Woori Financial (WF) F-4/A 28 Sep 18 2018 Q2 Registration of securities (foreign) (amended) Financial data

Document and Entity Information

Document and Entity Information	6 Months Ended
	Jun. 30, 2018shares
Document and entity information [Abstract]
Entity Registrant Name	Woori Bank
Entity Central Index Key	1,264,136
Document Type	F-4/A
Document Period End Date	Jun. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	676,000,000

Consolidated Statements Of Fina

Consolidated Statements Of Financial Position	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)		Dec. 31, 2017KRW (₩)
ASSETS [Abstract]
Cash and cash equivalents	₩ 5,920,568,000,000		$ 5,325,210,000		₩ 6,908,286,000,000
Financial assets at fair value through profit or loss in accordance with IFRS 9	6,340,704,000,000	[1]	5,703,098,000	[1]	0
Financial assets at fair value through profit or loss in accordance with IAS 39	0		0		5,843,077,000,000
Financial assets at fair value through other comprehensive income	14,644,608,000,000	[1]	13,171,981,000	[1]	0
Available-for-sale financial assets	0		0		15,352,950,000,000
Securities at amortized cost	17,702,129,000,000	[1]	15,922,044,000		0
Held-to-maturity financial assets	0		0		16,749,296,000,000
Loans and other financial assets at amortized cost	277,720,003,000,000	[1]	249,793,131,000		0
Loans and receivables	0		0		267,106,204,000,000
Investments in joint ventures and associates	412,940,000,000		371,416,000		417,051,000,000
Investment properties	381,177,000,000		342,847,000		371,301,000,000
Premises and equipments	2,450,754,000,000		2,204,312,000		2,477,545,000,000
Intangible assets and goodwill	653,514,000,000		587,798,000		518,599,000,000
Assets held for sale	18,705,000,000		16,824,000		48,624,000,000
Current income tax assets	11,322,000,000		10,183,000		4,722,000,000
Deferred income tax assets	89,711,000,000		80,690,000		280,130,000,000
Derivative financial assets	12,395,000,000		11,149,000		59,272,000,000
Other assets	202,800,000,000		182,406,000		158,404,000,000
Total assets	326,561,330,000,000		293,723,089,000		316,295,461,000,000
LIABILITIES [Abstract]
Financial liabilities at fair value through profit or loss in accordance with IFRS 9	2,578,332,000,000	[1]	2,319,061,000	[1]	0
Financial liabilities at fair value through profit or loss in accordance with IAS 39	0		0		3,427,909,000,000
Deposits due to customers	237,900,166,000,000		213,977,483,000		234,695,084,000,000
Borrowings	15,899,599,000,000		14,300,773,000		14,784,706,000,000
Debentures	26,752,725,000,000		24,062,534,000		27,869,651,000,000
Provisions	386,374,000,000		347,521,000		410,470,000,000
Net Defined benefit liabilities	99,859,000,000		89,817,000		43,264,000,000
Current income tax liabilities	154,202,000,000		138,696,000		232,600,000,000
Deferred income tax liabilities	14,777,000,000		13,291,000		22,681,000,000
Derivative financial liabilities	67,505,000,000		60,717,000		67,754,000,000
Other financial liabilities	21,408,267,000,000		19,255,502,000		13,892,461,000,000
Other liabilities	302,913,000,000		272,453,000		283,981,000,000
Total liabilities	305,564,719,000,000		274,837,848,000		295,730,561,000,000
EQUITY [Abstract]
Owner's equity	20,790,188,000,000		18,699,575,000		20,365,892,000,000
Capital stock	3,381,392,000,000		3,041,367,000		3,381,392,000,000
Hybrid securities	2,763,256,000,000		2,485,389,000		3,017,888,000,000
Capital surplus	285,885,000,000		257,137,000		285,880,000,000
Other equity	(2,113,798,000,000)		(1,901,239,000)		(1,939,274,000,000)
Retained earnings	16,473,453,000,000		14,816,921,000		15,620,006,000,000
Non-controlling interests	206,423,000,000		185,666,000		199,008,000,000
Total equity	20,996,611,000,000		18,885,241,000		20,564,900,000,000
Total liabilities and equity	₩ 326,561,330,000,000		$ 293,723,089,000		₩ 316,295,461,000,000
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income	3 Months Ended			6 Months Ended
	Jun. 30, 2018KRW (₩)₩ / shares		Jun. 30, 2017KRW (₩)₩ / shares	Jun. 30, 2018KRW (₩)₩ / shares		Jun. 30, 2018USD ($)$ / shares		Jun. 30, 2017KRW (₩)₩ / shares
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Interest income	₩ 2,368,669,000,000		₩ 2,105,808,000,000	₩ 4,643,416,000,000		$ 4,176,485,000		₩ 4,189,584,000,000
Interest income on financial assets at fair value through profit or loss (IFRS 9)	13,367,000,000	[1]	0	28,537,000,000	[1]	25,667,000	[1]	0
Interest income on financial assets at fair value through other comprehensive income	62,170,000,000	[1]	0	119,446,000,000	[1]	107,435,000	[1]	0
Interest income on financial assets at amortized cost	2,293,132,000,000	[1]	0	4,495,433,000,000	[1]	4,043,383,000	[1]	0
Interest income on financial assets at fair value through profit or loss in accordance with IAS 39	0		13,074,000,000	0		0		26,806,000,000
Interest income on available-for-sale financial assets	0		67,667,000,000	0		0		144,067,000,000
Interest income on held-to-maturity financial assets	0		74,690,000,000	0		0		149,673,000,000
Interest income on loans and receivables	0		1,950,377,000,000	0		0		3,869,038,000,000
Interest expense	(971,346,000,000)		(818,232,000,000)	(1,878,942,000,000)		(1,690,000,000)		(1,639,264,000,000)
Net interest income	1,397,323,000,000		1,287,576,000,000	2,764,474,000,000		2,486,485,000		2,550,320,000,000
Fees and commissions income	555,400,000,000		506,281,000,000	1,113,006,000,000		1,001,084,000		1,013,893,000,000
Fees and commissions expense	(258,053,000,000)		(243,533,000,000)	(510,351,000,000)		(459,031,000)		(476,193,000,000)
Net fees and commissions income	297,347,000,000		262,748,000,000	602,655,000,000		542,053,000		537,700,000,000
Dividend income	14,151,000,000		19,617,000,000	49,704,000,000		44,706,000		59,445,000,000
Net gain (loss) on financial instruments at fair value through profit or loss (IFRS 9)	67,693,000,000	[1]	0	117,023,000,000	[1]	105,255,000	[1]	0
Gain (loss) on financial instruments at fair value through profit or loss (IAS 39)	0		12,066,000,000	0		0		(146,409,000,000)
Net gain (loss) on financial assets at fair value through other comprehensive income	475,000,000	[1]	0	1,287,000,000	[1]	1,158,000	[1]	0
Net gain (loss) on available-for-sale financial assets	0		88,387,000,000	0		0		104,172,000,000
Net gain (loss) on financial assets at amortized cost	9,361,000,000	[1]	0	30,886,000,000	[1]	27,780,000	[1]	0
Net gain (loss) on disposals of securities at amortized cost	0		0	431,000,000	[1]	388,000	[1]	0
Net gain (loss) on disposals of loans and other financial assets at amortized cost	9,361,000,000	[1]	0	30,455,000,000	[1]	27,392,000	[1]	0
Impairment losses due to credit loss	150,673,000,000		(204,486,000,000)	28,438,000,000		25,578,000		(283,763,000,000)
General and administrative expenses	(827,654,000,000)		(784,157,000,000)	(1,567,338,000,000)		(1,409,730,000)		(1,538,427,000,000)
Other net operating income (expenses)	(122,951,000,000)		(77,267,000,000)	(219,414,000,000)		(197,350,000)		201,190,000,000
Operating income	986,418,000,000		604,484,000,000	1,807,715,000,000		1,625,935,000		1,484,228,000,000
Share of losses of joint ventures and associates	7,681,000,000		(14,863,000,000)	(1,462,000,000)		(1,315,000)		(64,278,000,000)
Net other non-operating income (expenses)	1,398,000,000		11,697,000,000	(4,721,000,000)		(4,246,000)		9,998,000,000
Non-operating income (loss)	9,079,000,000		(3,166,000,000)	(6,183,000,000)		(5,561,000)		(54,280,000,000)
Net income before income tax expense	995,497,000,000		601,318,000,000	1,801,532,000,000		1,620,374,000		1,429,948,000,000
Income tax expense	(273,701,000,000)		(135,034,000,000)	(485,216,000,000)		(436,424,000)		(320,933,000,000)
Net income	721,796,000,000		466,284,000,000	1,316,316,000,000		1,183,950,000		1,109,015,000,000
Other comprehensive income [abstract]
Net gain on equity securities of financial assets measured at fair value through other comprehensive income, net of tax	2,490,000,000	[1]	0	31,428,000,000	[1]	28,268,000	[1]	0
Net gain on valuation of financial liabilities designated as at FVTPL due to own credit risk	40,000,000	[1]	0	130,000,000	[1],[2]	117,000		0
Items out of change in equity method securities due to change in equity of investee that will not be reclassified to profit or loss	1,145,000,000		(41,000,000)	1,456,000,000		1,310,000		(3,087,000,000)
Remeasurement gain (loss) related to defined benefit plan	(6,113,000,000)		16,840,000,000	(59,573,000,000)		(53,583,000)		(9,677,000,000)
Items that will not be reclassified to profit or loss	(2,438,000,000)		16,799,000,000	(26,559,000,000)		(23,888,000)		(12,764,000,000)
Net gain on valuation of debt securities at FVTOCI	8,009,000,000	[1]	0	10,024,000,000	[1]	9,016,000	[1]	0
Net loss on valuation of AFS financial assets	0		(41,680,000,000)	0				(28,706,000,000)
Share of other comprehensive gain (loss) of joint ventures and associates	955,000,000		(156,000,000)	(246,000,000)		(221,000)		4,594,000,000
Gain (loss) on foreign currencies translation of foreign operations	37,268,000,000		31,450,000,000	35,526,000,000		31,954,000		(69,010,000,000)
Net loss on valuation of cash flow hedge	(2,787,000,000)		(673,000,000)	(6,213,000,000)		(5,588,000)		(1,526,000,000)
Net loss on disposal of assets held for sale	(4,709,000,000)		0	(4,709,000,000)		(4,236,000)		0
Items that may be reclassified to profit or loss	38,736,000,000		(11,059,000,000)	34,382,000,000		30,925,000		(94,648,000,000)
Other comprehensive income(loss), net of tax	36,298,000,000		5,740,000,000	7,823,000,000		7,037,000		(107,412,000,000)
Total comprehensive income	758,094,000,000		472,024,000,000	1,324,139,000,000		1,190,987,000		1,001,603,000,000
Net income attributable to:
Net income attributable to owners	716,142,000,000		460,888,000,000	1,305,878,000,000		1,174,562,000		1,098,361,000,000
Net Income (loss) attributable to non-controlling interests	5,654,000,000		5,396,000,000	10,438,000,000		9,388,000		10,654,000,000
Total comprehensive income attributable to:
Comprehensive income attributable to owners	751,528,000,000		464,129,000,000	1,315,322,000,000		1,183,056,000		995,742,000,000
Comprehensive income (loss) attributable to non-controlling interests	₩ 6,566,000,000		₩ 7,895,000,000	₩ 8,817,000,000		$ 7,931,000		₩ 5,861,000,000
Basic and diluted earnings from continuing and discontinued operations per share (Note 42) (Unit: Korean Won and U.S. Dollar) | (per share)	₩ 1,008		₩ 623	₩ 1,828		$ 1,644		₩ 1,497
[1]	The consolidated interim statements of comprehensive income for the three months and six months ended June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated interim statements of comprehensive income for the three months and six months ended June 30, 2017 was not retrospectively restated in accordance with IFRS 9.
[2]	The consolidated interim statements of changes in equity for the six months ended June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated interim statements of changes in equity for the six months ended June 30, 2017 was not retrospectively restated in accordance with IFRS 9.

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Equity	KRW (₩)		USD ($)	Owner's equityKRW (₩)		Owner's equityUSD ($)	Capital StockKRW (₩)	Capital StockUSD ($)	Hybrid securitiesKRW (₩)	Hybrid securitiesUSD ($)	Capital surplusKRW (₩)	Capital surplusUSD ($)	Other equityKRW (₩)		Other equityUSD ($)	Retained earningsKRW (₩)		Retained earningsUSD ($)	Non-controlling interestsKRW (₩)		Non-controlling interestsUSD ($)
Balance at beginning at Dec. 31, 2016	₩ 20,545,953,000,000			₩ 20,386,160,000,000			₩ 3,381,392,000,000		₩ 3,574,896,000,000		₩ 286,331,000,000		₩ (1,468,025,000,000)			₩ 14,611,566,000,000			₩ 159,793,000,000
Changes in equity [Abstract]
Net income	1,109,015,000,000			1,098,361,000,000			0		0		0		0			1,098,361,000,000			10,654,000,000
Dividends to common stocks	(270,842,000,000)			(269,308,000,000)			0		0		0		0			(269,308,000,000)			(1,534,000,000)
Capital increase of subsidiaries	(257,000,000)			(257,000,000)			0		0		(257,000,000)		0			0			0
Net gain on valuation of financial liabilities designated as at FVTPL due to own credit risk	0
Gain (loss) on valuation of financial assets at FVTOCI	0
Net loss on valuation of AFS financial assets	(28,706,000,000)			(29,033,000,000)			0		0		0		(29,033,000,000)			0			327,000,000
Change in equity method securities due to change in equity of investees	1,507,000,000			1,507,000,000			0		0		0		1,507,000,000			0			0
Gain (loss) on foreign currencies translation of foreign operations	(69,010,000,000)			(63,944,000,000)			0		0		0		(63,944,000,000)			0			(5,066,000,000)
Net loss on valuation of cash flow hedge	(1,526,000,000)			(1,526,000,000)			0		0		0		(1,526,000,000)			0			0
Remeasurement gain (loss) related to defined benefit plan	(9,677,000,000)			(9,622,000,000)			0		0		0		(9,622,000,000)			0			(55,000,000)
Equity related to assets held for sale	0
Dividends to hybrid securities	(90,823,000,000)			(90,823,000,000)			0		0		0		0			(90,823,000,000)			0
Issuance of hybrid securities	559,565,000,000			559,565,000,000			0		559,565,000,000		0		0			0			0
Redemption of hybrid securities	(1,324,731,000,000)			(1,324,731,000,000)			0		(1,116,573,000,000)		0		(208,158,000,000)			0			0
Balance at end at Jun. 30, 2017	20,420,468,000,000			20,256,349,000,000			3,381,392,000,000		3,017,888,000,000		286,074,000,000		(1,778,801,000,000)			15,349,796,000,000			164,119,000,000
Balance at beginning at Dec. 31, 2017	20,564,900,000,000		$ 18,496,942,000	20,365,892,000,000		$ 18,317,946,000	3,381,392,000,000	$ 3,041,367,000	3,017,888,000,000	$ 2,714,416,000	285,880,000,000	$ 257,133,000	(1,939,274,000,000)		$ (1,744,265,000)	15,620,006,000,000		$ 14,049,295,000	199,008,000,000		$ 178,996,000
Changes in equity [Abstract]
Net income	1,316,316,000,000		1,183,950,000	1,305,878,000,000		1,174,562,000	0	0	0	0	0	0	0		0	1,305,878,000,000		1,174,562,000	10,438,000,000		9,388,000
Dividends to common stocks	(338,744,000,000)		(304,681,000)	(336,636,000,000)		(302,785,000)	0	0	0	0	0	0	0		0	(336,636,000,000)		(302,785,000)	(2,108,000,000)		(1,896,000)
Net gain on valuation of financial liabilities designated as at FVTPL due to own credit risk	130,000,000	[1],[2]	117,000	130,000,000	[1]	117,000	0	0	0	0	0	0	130,000,000	[1]	117,000	0		0	0		0
Gain (loss) on valuation of financial assets at FVTOCI	41,452,000,000	[1]	37,284,000	41,736,000,000	[1]	37,539,000	0	0	0	0	0	0	41,736,000,000	[1]	37,539,000			0	(284,000,000)	[1]	(255,000)
Changes in other comprehensive income due to disposal of equity securities at fair value through other comprehensive income	0		0	0		0	0	0	0	0	0	0	424,000,000	[1]	381,000	(424,000,000)	[1]	(381,000)	0		0
Net loss on valuation of AFS financial assets	0
Change in equity method securities due to change in equity of investees	(7,496,000,000)		(6,742,000)	(7,496,000,000)		(6,742,000)	0	0	0	0	0	0	1,210,000,000		1,089,000	(8,706,000,000)		(7,831,000)	0		0
Gain (loss) on foreign currencies translation of foreign operations	35,526,000,000		31,954,000	36,769,000,000		33,072,000	0	0	0	0	0	0	36,769,000,000		33,072,000	0		0	(1,243,000,000)		(1,118,000)
Net loss on valuation of cash flow hedge	(6,213,000,000)		(5,588,000)	(6,213,000,000)		(5,588,000)	0	0	0	0	0	0	(6,213,000,000)		(5,588,000)	0		0	0		0
Remeasurement gain (loss) related to defined benefit plan	(59,573,000,000)		(53,583,000)	(59,480,000,000)		(53,499,000)	0	0	0	0	0	0	(59,480,000,000)		(53,499,000)	0		0	(93,000,000)		(84,000)
Equity related to assets held for sale	(4,709,000,000)		(4,236,000)	(4,709,000,000)		(4,236,000)	0	0	0	0	0	0	(4,709,000,000)		(4,236,000)	0		0	0		0
Dividends to hybrid securities	(75,603,000,000)		(68,000,000)	(75,603,000,000)		(68,000,000)	0	0	0	0	0	0	0		0	(75,603,000,000)		(68,000,000)	0		0
Issuance of hybrid securities	0		0
Redemption of hybrid securities	(255,000,000,000)		(229,358,000)	(255,000,000,000)		(229,358,000)	0	0	(254,632,000,000)	(229,027,000)	0	0	(368,000,000)		(331,000)	0		0	0		0
Appropriation of retained earnings			0	0		0	0	0	0	0	0	0	208,158,000,000		187,226,000	(208,158,000,000)		(187,226,000)	0		0
Capital decrease of subsidiaries	(13,000,000)		(12,000)	5,000,000		4,000	0	0	0	0	5,000,000	4,000			0			0	(18,000,000)		(16,000)
Balance at end at Jun. 30, 2018	20,996,611,000,000		18,885,241,000	20,790,188,000,000		18,699,575,000	3,381,392,000,000	3,041,367,000	2,763,256,000,000	2,485,389,000	285,885,000,000	257,137,000	(2,113,798,000,000)		(1,901,239,000)	16,473,453,000,000		14,816,921,000	206,423,000,000		185,666,000
Cumulative effect of changes in accounting policy	(214,362,000,000)		(192,806,000)	(215,085,000,000)		(193,457,000)	0	0	0	0	0	0	(392,176,000,000)		(352,740,000)	177,091,000,000		159,283,000	723,000,000		651,000
Adjusted balance, beginning of period	20,350,538,000,000		18,304,136,000	20,150,807,000,000		18,124,489,000	3,381,392,000,000	3,041,367,000	3,017,888,000,000	2,714,416,000	285,880,000,000	257,133,000	(2,331,450,000,000)		(2,097,005,000)	15,797,097,000,000		14,208,578,000	199,731,000,000		179,647,000
Changes in equity [Abstract]
Changes in other comprehensive income due to redemption of financial liabilities designated as at FVTPL	₩ 0		$ 0	₩ 0		$ 0	₩ 0	$ 0	₩ 0	$ 0	₩ 0	$ 0	₩ (5,000,000)	[1]	$ (4,000)	₩ 5,000,000	[1]	$ 4,000	₩ 0		$ 0
[1]	The consolidated interim statements of changes in equity for the six months ended June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated interim statements of changes in equity for the six months ended June 30, 2017 was not retrospectively restated in accordance with IFRS 9.
[2]	The consolidated interim statements of comprehensive income for the three months and six months ended June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated interim statements of comprehensive income for the three months and six months ended June 30, 2017 was not retrospectively restated in accordance with IFRS 9.

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows	6 Months Ended
	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)		Jun. 30, 2017KRW (₩)
Cash flows from operating activities
Net income	₩ 1,316,316,000,000		$ 1,183,950,000		₩ 1,109,015,000,000
Adjustments
Income tax expense	485,216,000,000		436,424,000		320,933,000,000
Interest income	(4,643,416,000,000)		(4,176,485,000)		(4,189,584,000,000)
Interest expense	1,878,942,000,000		1,690,000,000		1,639,264,000,000
Dividend income	(49,704,000,000)		(44,706,000)		(59,445,000,000)
Sub-total	(2,328,962,000,000)		(2,094,767,000)		(2,288,832,000,000)
Additions of expenses not involving cash outflows:
Impairment losses recognised due to credit loss	0		0		283,763,000,000
Share of losses of investments in joint ventures and associates	16,809,000,000		15,119,000		67,594,000,000
Loss on disposal of investments in joint ventures and associates	2,931,000,000		2,636,000		27,730,000,000
Loss on transaction and valuation of derivatives (hedging)	62,366,000,000		56,095,000		31,131,000,000
Loss on hedged items (fair value hedge)	0		0		15,846,000,000
Loss on provision	38,553,000,000		34,676,000		35,665,000,000
Retirement benefits	71,631,000,000		64,428,000		71,902,000,000
Depreciation and amortization	126,886,000,000		114,127,000		121,361,000,000
Loss on disposal of premises and equipment and other assets	221,000,000		199,000		608,000,000
Impairment loss on premises and equipment and other assets	2,000,000		2,000		160,000,000
Loss on financial assets at FVTOCI	477,000,000	[1]	429,000	[1]	0
Additions of expenses not involving cash outflows (sub-total)	319,876,000,000		287,711,000		655,760,000,000
Deductions of income not involving cash inflows:
Reversal of impairment losses due to credit loss	28,438,000,000		25,578,000		0
Gain on valuation of financial assets at FVTPL (IFRS 9)	167,268,000,000	[1]	150,448,000	[1]	0
Gain on valuation of financial instruments at FVTPL (IAS 39)	0		0		7,859,000,000
Gain on financial assets at FVTOCI	1,764,000,000	[1]	1,587,000	[1]	0
Gain on AFS financial assets	0		0		104,172,000,000
Gain on disposal of securities at amortized cost	431,000,000	[1]	388,000	[1]	0
Share of profits of investments in joint ventures and associates	15,347,000,000		13,804,000		3,316,000,000
Gain on disposal of investments in joint ventures and associates	0		0		32,886,000,000
Gain on transaction and valuation of derivatives (hedging)	28,943,000,000		26,033,000		11,656,000,000
Gain on hedged items (fair value hedge)	66,555,000,000		59,862,000		11,860,000,000
Gain on provisions	1,220,000,000		1,097,000		1,285,000,000
Gain on disposal of premises and equipment and other assets	17,037,000,000		15,324,000		1,675,000,000
Reversal of impairment loss on premises and equipment and other assets	341,000,000		307,000		32,000,000
Deductions of income not involving cash inflows (sub-total)	327,344,000,000		294,428,000		174,741,000,000
Changes in operating assets and liabilities:
Financial assets at FVTPL (IFRS 9)	440,367,000,000	[1]	396,085,000	[1]	0
Financial assets at FVTPL (IAS 39)	0		0		(187,086,000,000)
Loans and other financial assets at amortized cost	(10,667,142,000,000)	[1]	(9,594,479,000)	[1]	0
Loans and receivables	0		0		(7,908,486,000,000)
Other assets	85,119,000,000		76,560,000		(995,000,000)
Deposits due to customers	3,149,083,000,000		2,832,419,000		5,182,735,000,000
Provisions	(26,838,000,000)		(24,139,000)		(98,114,000,000)
Net defined benefit liability	(97,206,000,000)		(87,431,000)		(19,799,000,000)
Other financial liabilities	7,366,307,000,000		6,625,568,000		2,790,480,000,000
Other liabilities	11,536,000,000		10,376,000		(29,837,000,000)
Changes in operating assets and liabilities (sub-total)	261,226,000,000		234,959,000		(271,102,000,000)
Cash received from (paid for) operating activities:
Interest income received	4,609,449,000,000		4,145,934,000		4,281,385,000,000
Interest expense paid	(1,776,933,000,000)		(1,598,249,000)		(1,749,917,000,000)
Dividends received	49,917,000,000		44,897,000		62,014,000,000
Income tax paid	(312,471,000,000)		(281,050,000)		(236,246,000,000)
Net cash provided by operating activities	1,811,074,000,000		1,628,957,000		1,387,336,000,000
Cash in-flows from investing activities [Abstract]
Disposal of financial assets at FVTPL (IFRS 9)	5,316,190,000,000	[1]	4,781,606,000	[1]	0
Disposal of financial assets at FVTOCI	4,280,921,000,000	[1]	3,850,442,000	[1]	0
Disposal of AFS financial assets	0		0		13,312,489,000,000
Redemption of securities at amortized cost	4,873,896,000,000	[1]	4,383,788,000	[1]	0
Redemption of HTM financial assets	0		0		4,665,209,000,000
Disposal of investments in joint ventures and associates	3,855,000,000		3,467,000		62,974,000,000
Disposal of investment properties	2,076,000,000		1,867,000		162,000,000
Disposal of premises and equipment	119,000,000		107,000		1,042,000,000
Disposal of intangible assets	3,779,000,000		3,399,000		933,000,000
Disposal of assets held for sale	50,190,000,000		45,143,000		6,488,000,000
Cash in-flows from investing activities (sub-total)	14,531,026,000,000		13,069,819,000		18,049,297,000,000
Cash out-flows from investing activities [Abstract]
Net cash in-flows of business combination	71,559,000,000		64,363,000		0
Acquisition of financial assets at FVTPL (IFRS 9)	5,342,987,000,000	[1]	4,805,709,000	[1]	0
Acquisition of financial assets at FVTOCI	5,075,580,000,000	[1]	4,565,192,000	[1]	0
Acquisition of available-for-sale financial assets	0		0		11,268,756,000,000
Acquisition of securities at amortized cost	5,829,462,000,000	[1]	5,243,265,000	[1]	0
Acquisition of HTM financial assets	0		0		5,945,147,000,000
Acquisition of investments in joint ventures and associates	20,048,000,000		18,032,000		13,485,000,000
Acquisition of investment properties	7,311,000,000		6,576,000		1,221,000,000
Acquisition of premises and equipment	42,695,000,000		38,402,000		68,596,000,000
Acquisition of intangible assets	107,344,000,000		96,550,000		97,977,000,000
Cash out-flows from investing activities (sub-total)	16,496,986,000,000		14,838,089,000		17,395,182,000,000
Net cash provided by (used in) investing activities	(1,965,960,000,000)		(1,768,270,000)		654,115,000,000
Cash in-flows from financing activities [Abstract]
Increase in borrowings	4,972,075,000,000		4,472,095,000		4,349,952,000,000
Issuance of debentures	10,100,189,000,000		9,084,538,000		10,299,507,000,000
Issuance of hybrid securities	0		0		559,565,000,000
Cash in-flows from financing activities (sub-total)	15,072,264,000,000		13,556,633,000		15,209,024,000,000
Cash out-flows from financing activities [Abstract]
Repayment of borrowings	4,114,751,000,000		3,700,981,000		7,432,992,000,000
Repayment of debentures	11,441,709,000,000		10,291,158,000		8,223,263,000,000
Payment of dividends	336,636,000,000		302,785,000		269,308,000,000
Dividends paid on hybrid securities	75,683,000,000		68,071,000		100,627,000,000
Redemption of hybrid securities	255,000,000,000		229,358,000		1,323,400,000,000
Dividends paid on non-controlling interests	2,108,000,000		1,896,000		1,534,000,000
Cash out-flows from financing activities (sub-total)	16,225,887,000,000		14,594,249,000		17,351,124,000,000
Net cash used in financing activities	(1,153,623,000,000)		(1,037,616,000)		(2,142,100,000,000)
Net decrease in cash and cash equivalents	(1,308,509,000,000)		(1,176,929,000)		(100,649,000,000)
Cash and cash equivalents, beginning of the period	6,908,286,000,000		6,213,605,000		7,591,324,000,000
Effects of exchange rate changes on cash and cash equivalents	320,791,000,000		288,534,000		(113,551,000,000)
Cash and cash equivalents, end of the period (Note 6)	₩ 5,920,568,000,000		$ 5,325,210,000		₩ 7,377,124,000,000
[1]	The consolidated interim statements of cash flows for the six months ended June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated interim statements of cash flows for the six months ended June 30, 2017 was not retrospectively restated to apply IFRS 9.

General

General	6 Months Ended
	Jun. 30, 2018
Disclosure of notes and other explanatory information [Abstract]
General	1. GENERAL (1) Summary of the parent company Woori Bank (hereinafter referred to the “Bank”), which is a controlling entity in accordance with International Financial Reporting Standards (“IFRS”) 10 – Consolidated Financial Statements Previously, Woori Finance Holdings Co., Ltd., the former holding company of Woori Financial Group, established on March 27, 2001 held a 100% ownership of the Bank. Effective November 1, 2014, Woori Finance Holdings Co., Ltd. completed its merger (the “Merger”) with and into the Bank. Accordingly, the shares of the Bank, 597 million shares, prior to the merger, were reduced to nil in accordance with capital reduction procedure, and then, in accordance with the merger ratio, the Bank newly issued 676 million shares. As a result, as of June 30, 2018, the common stock of the Bank amounts to 3,381,392 million Korean Won. During the year ended December 31, 2016, the Korea Deposit Insurance Corporation (“KDIC”), the majority shareholder of the Bank, sold its 187 million shares in the Bank in accordance with the contract of “Disposal of Woori Bank’s shares to Oligopolistic Shareholders”. In addition to the sale, during the year ended December 31, 2017, KDIC sold additional 33 million shares. As of June 30, 2018 and December 31, 2017, KDIC held 125 million shares (18.43% ownership interest), of the Bank’s shares issued. On June 24, 2002, Woori Finance Holdings Co., Ltd. listed its common shares on the Korea Exchange through public offering. In addition, on September 29, 2003, the holding company registered with the Securities and Exchange Commission in the United States of America and, on the same day, listed its American Depositary Shares on the New York Stock Exchange. As Woori Finance Holdings Co., Ltd. was merged into the Bank, the Bank, which is the existing company, succeeded such rights and obligations as a listed company on the Korea Exchange and the New York Stock Exchange. As a result of such merger, the Bank incorporated Woori Card Co., Ltd., Woori Investment Bank Co., Ltd., Woori FIS Co., Ltd., Woori Private Equity Asset Management Co., Ltd., and Woori Finance Research Institute Co., Ltd. as its subsidiaries. The headquarters of the Bank is located in 51, Sogong-ro, (2) The consolidated financial statements for Woori Bank and its subsidiaries (the “Group”) include the following subsidiaries: Percentage of ownership Location Financial Subsidiaries Main business June 30, December 31, Woori Bank: Woori FIS Co., Ltd. System software 100.0 100.0 Korea June 30 Woori Private Equity Asset Management Co., Ltd. Finance 100.0 100.0 Korea June 30 Woori Finance Research Institute Co., Ltd. Other service 100.0 100.0 Korea June 30 Woori Card Co., Ltd. Finance 100.0 100.0 Korea June 30 Woori Investment Bank Co., Ltd. Other credit 59.8 59.8 Korea June 30 Woori Credit Information Co., Ltd. Credit information 100.0 100.0 Korea June 30 Woori America Bank Finance 100.0 100.0 U.S.A. June 30 Woori Global Markets Asia Limited ” 100.0 100.0 Hong Kong June 30 Woori Bank China Limited ” 100.0 100.0 China June 30 AO Woori Bank ” 100.0 100.0 Russia June 30 PT Bank Woori Saudara Indonesia 1906 Tbk ” 79.9 79.9 Indonesia June 30 Banco Woori Bank do Brasil S.A. ” 100.0 100.0 Brazil June 30 Korea BTL Infrastructure Fund ” 99.9 99.9 Korea June 30 Woori Fund Service Co., Ltd. ” 100.0 100.0 Korea June 30 Woori Finance Cambodia PLC. ” 100.0 100.0 Cambodia June 30 Woori Finance Myanmar Co., Ltd. ” 100.0 100.0 Myanmar June 30 Wealth Development Bank ” 51.0 51.0 Philippines June 30 Woori Bank Vietnam Limited ” 100.0 100.0 Vietnam June 30 WB Finance Co., Ltd. ” 100.0 — Cambodia June 30 Kumho Trust First Co., Ltd. (*1) Asset securitization 0.0 0.0 Korea June 30 Asiana Saigon Inc. (*1) ” 0.0 0.0 Korea June 30 Consus Eighth Co., LLC (*1) ” 0.0 0.0 Korea June 30 KAMCO Value Recreation First Securitization Specialty Co., Ltd. (*1) ” 15.0 15.0 Korea June 30 Hermes STX Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 BWL First Co., LLC (*1) ” 0.0 0.0 Korea June 30 Deogi Dream Fourth Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Jeonju Iwon Ltd. (*1) ” 0.0 0.0 Korea June 30 Wonju I one Inc. (*1) ” 0.0 0.0 Korea June 30 Heitz Third Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Woorihansoop 1st Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Electric Cable First Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Woori International First Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Woori HJ First Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Woori WEBST 1st Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Wibihansoop 1st Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 HNLD 1st Inc.(*4) ” — 0.0 Korea — Percentage of ownership Location Financial Subsidiaries Main business June 30, December 31, Uri QS 1st Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Uri Display 1st Co., Ltd.(*1) ” 0.0 0.0 Korea June 30 Tiger Eyes 2nd Co., Ltd.(*1) ” 0.0 0.0 Korea June 30 Woori Serveone 1st Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Uri Display 2nd Co.,Ltd. (*1) ” 0.0 — Korea June 30 Woori the Colony Unjung Securitization Specialty Co., Ltd. (*1) ” 0.0 — Korea June 30 Woori Dream 1st Co., Ltd. (*1) ” 0.0 — Korea June 30 Woori HS 1st Co., Ltd. (*1) ” 0.0 — Korea June 30 Smart Casting Inc. (*1) ” 0.0 — Korea June 30 HeungkukWoori Tech Company Private Placement Investment Trust No. 1 and 6 beneficiary certificates (*2) Securities investment — — Korea June 30 Principle Guaranteed Trust (*3) Trust 0.0 0.0 Korea June 30 Principle and Interest Guaranteed Trust (*3) ” 0.0 0.0 Korea June 30 Woori Investment Bank: Dongwoo First Securitization Specialty Co., Ltd. (*1) Asset securitization 5.0 5.0 Korea June 30 Seari First Securitization Specialty Co., Ltd. (*1) ” 5.0 5.0 Korea June 30 Namjong 1st Securitization Specialty Co., Ltd. (*1) ” 5.0 5.0 Korea June 30 Bukgeum First Securitization Specialty Co., Ltd. (*1) ” 5.0 5.0 Korea June 30 Seori Second Securitization Specialty Co., Ltd. (*1) Asset securitization 5.0 — Korea June 30 Bukgeum Second Securitization Specialty Co., Ltd. (*1) ” 5.0 — Korea June 30 Woori Card Co., Ltd.: TUTU Finance-WCI Finance 100.0 100.0 Myanmar June 30 Woori Card one of 2017-1 Asset securitization 0.5 0.5 Korea June 30 Woori Card one of 2017-2 ” 0.5 0.5 Korea June 30 (*1) The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns. (*2) The entity was a structured entity for the purpose of investment in securities and was in scope for consolidation, considering that the Group 1) had the power over the investee, 2) was exposed, or has rights, to variable returns from its involvement with the investee, and 3) has the ability to use its power to affect its returns. (*3) The entity was a money trust under the Financial Investment Services and Capital Markets Act and was in scope for consolidation. Although the Group was not a majority shareholder, the Group 1) has the power over the investee, 2) was exposed, or has rights, to variable returns from its involvement with the investee, and 3) has the ability to use its power to affect its returns. (*4) The entity is a structured entity for the purpose of asset securitization and is not in scope for consolidation considering that the Group 1) does not have the power over the investee, 2) is not exposed, or does not have rights to variable returns from its involvement with the investee, and 3) does not have the ability to use its power to affect its returns. (3) As of June 30, 2018, and December 31, 2017, despite having more than 50% ownership interest, the Group has not consolidated the following companies as the Group does not have the ability to control following subsidiaries: As of June 30, 2018 Subsidiaries Location Main Percentage of Golden Bridge NHN Online Private Equity Investment (*) Korea Securities Investment 60.0 Mirae Asset Maps Clean Water Private Equity Investment Trust 7th (*) Korea Securities Investment 57.1 Kiwoom Yonsei Private Equity Investment Trust (*) Korea Securities Investment 88.3 Hana Walmart Real Estate Investment Trust 41-1 Korea Securities Investment 77.0 IGIS Global Private Placement Real Estate Fund No. 148-1 (*) Korea Securities Investment 75.0 IGIS Global Private Placement Real Estate Fund No. 148-2 (*) Korea Securities Investment 75.0 Mirae Asset Seoul Ring Expressway Private Special Asset Fund I (*) Korea Securities Investment 66.2 Hangkang Sewage Treatment Plant Fund (*) Korea Securities Investment 55.6 Consus KyungJu Green Private Placement Real Estate Fund 1 st Korea Securities Investment 52.4 (*) The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities. As of December 31, 2017 Subsidiaries Location Main Percentage of Golden Bridge NHN Online Private Equity Investment (*) Korea Securities Investment 60.0 Mirae Asset Maps Clean Water Private Equity Investment Trust 7th (*) Korea Securities Investment 59.7 Kiwoom Yonsei Private Equity Investment Trust (*) Korea Securities Investment 88.9 Hana Walmart Real Estate Investment Trust 41-1 Korea Securities Investment 90.1 IGIS Global Private Placement Real Estate Fund No. 148-1 (*) Korea Securities Investment 75.0 IGIS Global Private Placement Real Estate Fund No. 148-2 (*) Korea Securities Investment 75.0 (*) The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities. (4) The summarized financial information before the elimination of intercompany transactions of the subsidiaries whose financial information was prepared under IFRS for the Group’s consolidated financial statements is as follows (Unit: Korean Won in millions): As of and for the six months ended June 30, 2018 Assets Liabilities Operating Net income Comprehensive Woori FIS Co., Ltd. 80,851 55,312 138,088 (7,006 ) (7,040 ) Woori Private Equity Asset Management Co., Ltd. 40,799 2,064 556 (1,493 ) (1,490 ) Woori Finance Research Institute Co., Ltd. 4,314 615 2,776 258 258 Woori Card Co., Ltd. 9,100,890 7,462,577 944,657 67,618 62,866 Woori Investment Bank Co., Ltd. 2,723,251 2,418,664 109,428 14,722 14,878 Woori Credit Information Co., Ltd. 34,130 6,167 17,601 839 839 Woori America Bank 2,073,420 1,777,327 42,624 11,186 24,091 Woori Global Markets Asia Limited 406,684 287,622 7,302 2,156 7,298 Woori Bank China Limited 5,120,070 4,596,883 143,390 7,382 25,267 AO Woori Bank 277,555 224,860 8,778 2,570 200 PT Bank Woori Saudara Indonesia 1906 Tbk 2,349,222 1,858,176 96,177 22,401 15,947 Banco Woori Bank do Brasil S.A. 155,083 125,288 7,341 882 (2,515 ) Korea BTL Infrastructure Fund 777,576 297 14,704 12,865 12,865 Woori Fund Service Co., Ltd. 13,411 977 4,922 1,023 1,023 Woori Finance Cambodia PLC. 73,212 52,584 4,912 1,277 2,197 Woori Finance Myanmar Co., Ltd. 19,837 6,496 2,086 (187 ) 412 Wealth Development Bank 185,866 152,414 6,240 (2 ) (788 ) Woori Bank Vietnam Limited 1,142,018 990,228 23,746 3,545 8,822 WB Finance Co., Ltd. 227,582 186,772 — — — Money trust under the FISCM Act (*) 1,573,367 1,543,491 24,029 (36 ) (36 ) Structured entity for the securitization of financial assets 1,226,022 1,631,837 32,089 12,202 5,725 Structured entity for the investments in securities 41,221 40 785 (798 ) (1,869 ) (*) FISCM Act: Financial Investment Services and Capital Markets Act As of and for the year ended December 31, 2017 Assets Liabilities Operating Net income Comprehensive Woori FIS Co., Ltd. 103,932 71,386 252,460 1,940 (2,963 ) Woori Private Equity Asset Management Co., Ltd. 42,894 2,670 7,257 (4,114 ) (4,074 ) Woori Finance Research Institute Co., Ltd. 3,790 350 4,733 83 64 Woori Card Co., Ltd. 8,605,993 6,973,705 1,771,157 101,214 107,321 Woori Investment Bank Co., Ltd. 1,880,157 1,588,610 183,376 20,023 20,210 Woori Credit Information Co., Ltd. 33,298 6,175 31,580 861 752 Woori America Bank 1,954,301 1,679,248 81,337 11,869 (16,833 ) Woori Global Markets Asia Limited 290,226 178,343 11,345 1,922 (12,544 ) Woori Bank China Limited 4,960,637 4,458,683 388,913 13,809 (15,252 ) AO Woori Bank 201,704 149,101 15,656 4,748 1,217 As of and for the year ended December 31, 2017 Assets Liabilities Operating Net income Comprehensive PT Bank Woori Saudara Indonesia 1906 Tbk 2,230,617 1,745,171 192,485 38,488 (18,689 ) Banco Woori Bank do Brasil S.A. 213,889 181,544 20,455 1,843 (2,840 ) Korea BTL Infrastructure Fund 786,480 301 30,240 26,390 26,390 Woori Fund Service Co., Ltd. 12,653 1,242 9,021 1,398 1,398 Woori Finance Cambodia PLC. 51,304 32,873 5,895 983 (473 ) Woori Finance Myanmar Co., Ltd. 18,236 5,307 2,506 791 15 Wealth Development Bank 191,049 156,808 13,632 1,323 (1,093 ) Woori Bank Vietnam Limited 775,758 632,160 29,698 2,436 (15,347 ) Money trust under the FISCM Act (*) 1,560,672 1,530,760 44,344 582 582 Structured entity for the securitization of financial assets 867,583 1,275,719 22,730 1,179 (2,800 ) Structured entity for the investments in securities 34,939 76 377 (475 ) (38,592 ) (*) FISCM Act: Financial Investment Services and Capital Markets Act (5) The financial support that the Group provides to consolidated structured entities is as follows: - Structured entity for the securitization of financial assets The structured entity is established for the purpose of securitization of project financing loans, corporate bonds, and other financial assets. The Group is involved with the structured entity through providing with credit facility over asset-backed commercial papers issued by the entity, originating loans directly to the structured entity, or purchasing 100% of the subordinated debts issued by the structured entity. - Structured entity for the investments in securities The structured entity is established for the purpose of investments in securities. The Group acquires beneficiary certificates through its contribution of fund to the structured entity, and it is exposed to the risk that it may not be able to recover its fund depending on the result of investment performance of asset managers of the structured entity. - Money trust under the Financial Investment Services and Capital Markets Act The Group provides with financial guarantee of principal and interest or principal only to some of its trust products. Due to the financial guarantees, the Group may be obliged to supplement when the principal and interest or principal of the trust product sold is short of the guaranteed amount depending on the result of investment performance of the trust product. - The Group is providing purchase commitment and credit facilities to structured entities that are subsidiaries of the Group. Purchase commitments guarantee the purchase and payment of outstanding commercial papers that were issued but were not repurchased by the structured entities. Credit facilities allow lending of funds to structured entities under certain conditions when there are grounds for discontinuing the issuance of commercial papers, or when structured entities default due to some reasons. As of June 30, 2018, the Group is providing credit facilities (including ABCP purchase commitments, etc.) amounting to 1,156,431 million Won to aforementioned structured entities. (6) The Group has entered into various agreements with structured entities such as asset securitization vehicles, structured finance and investment funds, and monetary funds. Where it is determined in accordance with IFRS 10 that the Group has no controlling power over such structured entities, the entities are not consolidated. The nature of interests, which the Group retains, and the risks, to which the Group is exposed, of the unconsolidated structured entities are as follows: The interests to unconsolidated structured entities, which the Group retains, are classified to asset securitization vehicles, structured finance and investment fund, based on the nature and the purpose of the structured entities. Asset securitization vehicle issues asset-backed securities and redeems the principal and interest or distributes dividends on asset-backed securities with profits from collecting cash flows or sale of securitized assets. The Group, as a secondary guarantor, provides purchase commitments for its asset-backed securities or guarantees to such asset securitization vehicle and recognizes commission income or interest income related to the commitment or guarantees. Therefore, the Group would be exposed to risks to purchases or pays back asset-backed securities issued by the vehicles when a primary guarantor fails to provide the financing asset securitization vehicles. Structured finance includes investments in project financing on real estates, social overhead capital (“SOC”), infrastructure and shipping finance. They are formed as special purpose entity by funding through equity investments and loans from various investors. Investment decisions are made by the Group based on business outlook of such projects. In relation to such investments, the Group recognizes interest income on loans, gains or losses on valuation of equity investments or dividend income. The structured finance is secured by additional funding agreement, guarantee or credit facilities. However, the structured financing project would fail to return the capital of equity investments or principal of loans to the Group if it is discontinued or did not achieve business outcome. Investment funds include trusts and private equity funds. A trust is formed by contributions from various investors, operated by a manager engaged to the trust and distributed proceeds from sales of investments to the investors. A private equity fund is established in order to acquire ownership interests in a portfolio company with exit strategy after implementing financial and operational restructuring of the company. The Group recognizes unrealized gains or losses on change in value of investments in proposition of ownership interests in investments. The Group would be exposed to risks of loss when the value of portfolio investment is decreased. Total assets of the unconsolidated structured entities, the carrying value of the related items recorded, the maximum exposure to risks, and the loss recognized in conjunction with the unconsolidated structured entities as of June 30, 2018 and December 31, 2017 are as follows (Unit: Korean Won in millions): June 30, 2018 Asset Structured Investment Total asset of the unconsolidated structured entities 7,955,990 36,949,944 14,777,372 Assets recognized in the consolidated financial statements related to the unconsolidated structured entities 2,956,395 2,162,493 1,333,612 Financial assets at FVTPL 232,931 69,259 1,079,544 Financial assets at FVTOCI 499,861 49,538 — Financial assets at amortized cost 2,223,211 2,039,184 10,697 Investments in joint ventures and associates — 885 243,371 Derivative assets 392 3,627 — Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities 1,442 1,587 81 Derivative liabilities 361 749 — Other liabilities (including provisions) 1,081 838 81 The maximum exposure to risks 3,697,522 2,818,678 1,398,067 Investments 2,956,395 2,162,493 1,333,612 Credit facilities 741,127 656,185 64,455 Loss recognized on unconsolidated structured entities 158 8,757 9,110 December 31, 2017 Asset Structured Investment Total asset of the unconsolidated structured entities 7,295,601 40,172,830 13,641,135 Assets recognized in the consolidated financial statements related to the unconsolidated structured entities 3,215,159 2,314,043 1,138,523 Loans and receivables 43,180 1,969,760 — Financial assets held for trading — 233,428 10,160 AFS financial assets 902,390 106,819 904,774 HTM financial assets 2,269,451 — — Investments in joint ventures and associates — — 223,589 Derivative assets 138 4,036 — Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities 1,433 1,506 — Derivative liabilities 575 968 — Other liabilities (including provisions) 858 538 — The maximum exposure to risks 4,032,531 2,918,448 1,138,523 Investments 3,215,159 2,314,043 1,138,523 Credit facilities 817,372 604,405 — Loss recognized on unconsolidated structured entities 837 3,939 5,993 (7) Subsidiaries of which non-controlling 1) Accumulated non-controlling June 30, 2018 December 31, 2017 Woori Investment Bank 125,809 119,111 PT Bank Woori Saudara Indonesia 1906 Tbk 66,004 64,877 Wealth Development Bank 16,391 16,778 2) Net income attributable to non-controlling For the six months ended For the six months ended Woori Investment Bank 5,912 5,072 PT Bank Woori Saudara Indonesia 1906 Tbk 4,508 5,048 Wealth Development Bank (1 ) 515 3) Dividends to non-controlling For the six months ended For the six months ended PT Bank Woori Saudara Indonesia 1906 Tbk 2,082 1,513

Basis of preparation and signif

Basis of preparation and significant accounting policies	6 Months Ended
	Jun. 30, 2018
Accounting policies [Abstract]
Basis of preparation and significant accounting policies	2. BASIS OF PREPARATION AND SIGNIFICANT ACCOUNTING POLICIES Basis of presentation The Group’s consolidated interim financial statements are prepared in accordance with International Financial Reporting Standards (“IFRS”) 34, Interim Financial Reporting Consolidated Financial Statements Unless stated below, the accounting policies applied in preparing the accompanying consolidated interim financial statements have been applied consistently with the annual consolidated financial statements as of and for the year ended December 31, 2017. (1) The Group has newly adopted the following adoption of IFRS that affected the Group’s accounting policies: - Adoption of IFRS 9 – Financial instruments The Group applied for the first time as of January 1, 2018, the adoption to IFRS 9 and other standards related to IFRS 9, which introduces new rules: 1) classification and measurement of financial assets and financial liabilities, 2) impairment of financial assets, and 3) hedge accounting. The Group decided not to restate the prior period figures when applying the Standard for the first time, thus the comparative financial statements presented are not restated. The main contents of the new accounting standard and the effect on the financial statements of the Group are as follows: a) Classification and measurement of financial assets and financial liabilities All financial assets included in the scope of IFRS 9 are subsequently measured at amortized cost or fair value based on the business model for the management of financial assets and the nature of the contractual cash flows. Debt instruments that are held within a business model whose objective is to collect the contractual cash flows, and that have contractual cash flows that are solely payments of principal and interest on the principal outstanding are generally measured at amortized cost at the end of subsequent accounting periods (financial assets at amortized cost). Debt instruments that are held within a business model whose objective is achieved both by collecting contractual cash flows and selling financial assets, and that have contractual terms that give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding, are generally measured at fair value through other comprehensive income (financial assets at fair value through other comprehensive income (“FVTOCI”)). All other debt instruments and equity instruments are measured at their fair value at the end of subsequent accounting periods (financial assets at fair value through profit or loss (“FVTPL”)). Notwithstanding the foregoing, the Group may make the following irrevocable choice or designation at the time of initial recognition of financial assets. The Group may make an irrevocable election to present in other comprehensive income subsequent changes in the fair value of an investment in an equity instrument within the scope of this Standard that is neither held for trading nor contingent consideration recognized by an acquirer in a business combination to which IFRS 3(R) applies. At initial recognition, financial assets at amortized cost or FVTOCI may be irrevocably designated as financial assets at fair value through profit or loss mandatorily measured at fair value if doing so eliminate or significantly reduce a measurement or recognition inconsistency. As of the date of first adoption of IFRS 9, there are no debt instruments classified either as financial assets at amortized cost or FVTOCI that are designated as financial assets at fair value through profit or loss. When debt instruments measured at FVTOCI are removed, the cumulative gain or loss recognized in other comprehensive income is reclassified from equity to profit or loss as a reclassification adjustment. On the other hand, for equity instruments designated as financial assets at fair value through other comprehensive income, cumulative gains or losses previously recognized in other comprehensive income are not subsequently reclassified to profit or loss. Debt instruments measured subsequently at amortized cost or fair value through other comprehensive income are subject to impairment provisions. The classification and measurement of financial assets and financial liabilities in accordance with IFRS 9 and IAS 39 as of January 1, 2018 are as follows (Unit: Korean Won in millions): Account Classification Classification Classification Reclassificati- Remeasure- Classification Deposit Loans and receivables Loan and other financial assets at amortized cost 8,870,835 — — 8,870,835 Deposit Financial assets at FVTPL Financial assets at FVTPL 25,972 — — 25,972 Debt securities Financial assets at FVTPL Financial assets at FVTPL(*) 2,654,027 — — 2,654,027 Equity securities Financial assets at FVTPL Financial assets at FVTPL(*) 47,304 — — 47,304 Derivatives Financial assets at FVTPL Financial assets at FVTPL(*) 3,115,775 (2,137 ) — 3,113,638 Equity securities Available-for-sale Financial assets at FVTPL(*) 1,273,498 1,219 — 1,274,717 Equity securities Available-for-sale Financial assets at FVTOCI 850,207 — — 850,207 Debt securities Available-for-sale Financial assets at FVTPL 46,855 — — 46,855 Debt securities Available-for-sale Financial assets at FVTOCI 12,874,209 — — 12,874,209 Debt securities Available-for-sale Securities at amortized cost 308,181 — 14,119 322,300 Debt securities Held to maturity financial assets Securities at amortized cost 16,749,296 — — 16,749,296 Loans Loans and receivables Financial assets at FVTPL (*) 279,032 918 50 280,000 Loans Loans and receivables Loan and other financial assets at amortized cost 253,014,491 — — 253,014,491 Derivatives Derivatives Derivatives 59,272 — — 59,272 Other financial assets Loans and receivables Loan and other financial assets at amortized cost 6,772,088 — — 6,772,088 Total financial assets 306,941,042 — 14,169 306,955,211 (*) Under IAS 39, the embedded derivatives out of hybrid financial instruments are accounted for as derivatives assets or liabilities if the criteria for separation of the embedded derivative are met and the rest of host contracts in those instruments are recorded as available-for-sale Account Classification Classification Classification Reclassifica- Remeasure- Classification Deposit due to customers Financial liabilities at FVTPL Financial liabilities at FVTPL 25,964 — — 25,964 Deposit due to customers Deposit due to customers Financial liabilities at amortized cost 234,695,084 — — 234,695,084 Borrowings Borrowings Financial liabilities at amortized cost 14,784,706 — — 14,784,706 Debentures Financial liabilities at FVTPL Financial liabilities at FVTPL 91,739 — — 91,739 Debentures Debentures Financial liabilities at amortized cost 27,869,651 — — 27,869,651 Equity-linked securities Financial liabilities at FVTPL Financial liabilities at FVTPL 160,057 — — 160,057 Derivatives liabilities Financial liabilities at FVTPL Financial liabilities at FVTPL 3,150,149 — — 3,150,149 Derivatives liabilities Derivatives liabilities Derivatives liabilities 67,754 — — 67,754 Other financial liabilities Other financial liabilities Financial liabilities at amortized cost 13,892,461 — — 13,892,461 Provision for financial guarantee Provision for financial guarantee Financial liabilities at amortized cost 71,697 — — 71,697 Total financial liabilities 294,809,262 — — 294,809,262 At the date of the initial application of IFRS 9, there were no financial assets or liabilities measured at FVTPL that were reclassified to FVTOCI or amortized cost category. As of the date of first adoption of IFRS 9, the amount of valuation gain or loss and the fair value of financial assets that would have been recognized in the book, had the entity decided not to reclassify financial assets at FVTPL or FVTOCI that has been reclassified into financial assets at amortized cost, are as follows: (Unit: Korean Won in millions) Account subject Category before the adoption of Amount of valuation gain/loss had Fair value Debt securities AFS securities (236 ) 302,638 b) Impairment of financial assets The impairment model under IFRS 9 reflects expected credit losses, as opposed to incurred credit losses under IAS 39. Under the impairment approach in IFRS 9, it is no longer necessary for a credit event to have occurred before credit losses are recognized. Instead, the Group accounts for expected credit losses and changes in those expected credit losses. The amount of expected credit losses should be updated at each reporting date to reflect changes in credit risk since initial recognition. The Group is required to recognize the expected credit losses for financial instruments measured at amortized cost or FVTOCI, and loan commitments and financial guarantee contracts that are subject to the impairment provisions of IFRS 9. In particular, when the credit risk of the financial instruments are significantly increased after initial recognition, or when the credit quality of the financial instruments are already impaired at acquisition, the loss allowance is measured as the expected credit loss for the whole life of the financial assets. If the credit risk of a financial instruments does not increase significantly after initial recognition (excluding POCI loans - for financial assets already impaired at initial recognition), the Group measures the loss allowance on the financial instruments at the amount equivalent to the expected 12-month Management determined the credit risk at the date of initial recognition of the financial instrument in accordance with IFRS 9 and provided a reasonable and supportive measure that can be used without undue cost or effort in comparison with the credit risk of the initial application date (January 1, 2018) the Group used information that could be used to assess the impairment of the Group’s financial assets, lending arrangements and financial guarantees at the date of initial application. As of January 1, 2018, the evaluation results are as follows (Unit: Korean Won in millions): Account Classification Classification Loss allowance Loss allowance Increases (B-A) Deposit Loans and receivables Loans and other financial assets at amortized cost 2,458 3,092 634 Debt securities AFS debt securities AFS financial assets Financial assets at FVTOCI — 4,236 4,236 HTM securities HTM financial assets Securities at amortized cost — 5,078 5,078 Loans and other financial assets Loans and receivables Loans and other financial assets at amortized cost 1,827,785 2,076,873 249,088 Payment guarantee 183,247 192,924 9,677 Loan commitment 66,115 104,985 38,870 Total 2,079,605 2,387,188 307,583 c) Classification and measurement of financial liabilities One of the major changes related to the classification and measurement of financial liabilities as a result of the adoption of IFRS 9 is the change in the fair value of financial liabilities designated at fair value through profit or loss due to the changes in issuer’s own credit risk. The Group recognizes the effect of changes in the credit risk of financial liabilities designated as at FVTOCI in other comprehensive income, except for cases where it causes or disproves accounting mismatch of the profit or loss. Changes in fair value due to credit risk of financial liabilities are not subsequently reclassified to profit or loss, but are reclassified as retained earnings when financial liabilities are eliminated. In accordance with IAS 39, the entire of changes in fair value of financial liabilities designated as at FVTPL are recognized in profit or loss. As of January 1, 2018, the Group designated 251,796 million Korean Won of FVTPL out of 294,813,795 million of financial liabilities, and recognized 133 million Korean Won as accumulated other comprehensive loss in relation to the changes in credit risk of financial liabilities. d) Hedge accounting The new hedge accounting model maintains three types of hedge accounting. However, it is introduced more flexibility in the types of transactions that are eligible for hedge accounting and is expanded the types of hedging instruments and non-financial In accordance with the transitional provisions of IFRS 9 on hedge accounting, the Group adopted the hedge accounting provisions of IFRS 9 prospectively from January 1, 2018. As of the date of initial application, the Group has considered that the hedging relationship in accordance with IAS 39 is appropriate for hedge accounting under IFRS 9, thus the hedging relationship is considered to exist continually. Since the major conditions for hedging instruments and the hedged items are consistent, all hedging relationships are consistent with the effectiveness assessment requirements of IFRS 9. The Group has not designated a hedging relationship in accordance with IFRS 9 in which the hedge relationship would not have met the requirements for hedge accounting under IAS 39. Consistent with prior periods, the Group continues to designate fair value changes in interest rate swaps as hedging instruments in the fair value hedge relationship. e) Effect on equity as a result of adoption of IFRS 9 The effect on equity due to the adoption of IFRS 9 as of January 1, 2018 is as follows (Unit: Korean Won in millions): - Impact on accumulated other comprehensive loss as result of financial assets at FVTOCI, etc. Amount Beginning balance (prior to IFRS 9) (89,723 ) Reclassification (392,177 ) Reclassification of available-for-sale 494 Reclassification of available-for-sale (152,124 ) Recognition of expected credit losses of debt securities at FVTOCI 4,293 Reclassified of available for sale financial assets (equity securities) to financial assets at FVTOCI (397,508 ) Effect on changes in credit risk of financial liabilities at fair value through profit or loss designated as upon initial recognition (133 ) Others 3,005 Income tax effect 149,796 Ending balance (based on IFRS 9) (481,900 ) - Retained earnings impact Amount Beginning balance (prior to IFRS 9) 15,620,006 Reclassification 177,091 Reclassification of available-for-sale (494 ) Reclassification of available-for-sale 152,067 Recognition of expected credit losses of debt instruments at FVTOCI (4,236 ) Reclassified of available for sale financial assets (equity securities) to financial assets at FVTOCI 397,508 Effect on revaluation of financial assets at amortized cost from loan and receivables or AFS financial assets 282 Recognition of expected credit losses of financial assets at amortized cost which were previously loan and receivables (240,683 ) Effect of payment guarantees / unused commitments on liabilities (48,548 ) Effect on changes in credit risk of financial liabilities at fair value through profit or loss designated as upon initial recognition 133 Others (4,456 ) Income tax effect (74,482 ) Ending balance (based on IFRS 9) 15,797,097 - Adoption of IFRS 15 – Revenue from contracts with customers (enacted) The Group adopted IFRS 15 for the first time and decided to retrospectively apply the cumulative effect of the first application of IFRS 15 as of January 1, 2018. In addition, the Standard has been retrospectively applied only to contracts that are not completed on the date of initial application, and all contractual changes made prior to the first application date are not rewritten. In addition, the Group decided not to restate the prior periods when applying IFRS 15 for the first time. Accordingly, the Group has not retroactively restated the comparative consolidated financial statements presented herein. - Amendments to IFRS 2 – Classification and Measurement of Share-based Payment Transactions The amendments clarify the following; i) In estimating the fair value of a cash-settled share-based payment, the accounting for the effects of vesting and non-vesting - Amendments to IAS 40 – Transfers of Investment Property The amendments clarify that a transfer to, or from, investment property necessitates an assessment of whether a property meets the definition of investment property, supported by observable evidence that a change in use has occurred. The amendments further clarify that the situations listed in IAS 40 are not exhaustive and that a change in use is possible for properties under construction (i.e. a change in use is not limited to completed properties). - Amendments to IFRIC 22 – Foreign Currency Transactions and Advance Consideration IFRIC 22 addresses how to determine the ‘date of transaction’ for the purpose of determining the exchange rate to use on initial recognition of an asset, expense or income (or part of them), when consideration for that item has been paid or received in advance in a foreign currency which resulted in the recognition of a non-monetary non-monetary non-refundable The Interpretation specifies that the date of transaction is the date on which the entity initially recognizes the non-monetary non-monetary - Annual Improvements to IFRS 2014-2016 Cycle The amendments include partial amendments to IFRS 1 ‘First-time Adoption of IFRS’ and IAS 28 ‘Investments in Associates and Joint Ventures.’ Amendments to IAS 28 provide that an investment company such as a venture capital investment vehicle may selectively designate each of its investment in associates and/or joint ventures to be measured at fair value through profit or loss mandatorily measured at fair value, and that such designation must be made at the time of each investment’s initial recognition. In addition, when non-investment There are no significant impacts on financial statements due to newly adopted accounting standards except for IFRS 9. (2) The Group has not applied the following IFRS that have been issued but are not yet effective: - IFRS 16—Leases (enacted) IFRS 16 introduces a comprehensive model for the identification of lease arrangements and accounting treatments for both lessors and lessees. IFRS 16 will supersede the current lease guidance including IAS 17 Leases and the related interpretations, and will be applied to periods beginning on or after January 1, 2019. IFRS 16 distinguishes leases and service contracts on the basis of whether an identified asset is controlled by a customer. Distinctions of operating leases and finance leases are removed for lessee accounting, and is replaced by model where a right-of-use The right-of-use In contrast to lessee accounting, IFRS 16 substantially carries forward the lessor accounting requirements in IAS 17, and continues to require a lessor to classify a lease either as an operating lease or a finance lease. Also, IFRS 16 requires expanded disclosures. According to the preliminary assessment of the Group, the lease agreements entered into by the Group as of June 30, 2018 are expected to meet the definition of lease under the Standard, and accordingly, if the Group adopts the Standard, it applies to all leases except short-term leases and leases of low value assets, and the Group will recognize the right-of-use

Significant accounting estimate

Significant accounting estimates and assumptions	6 Months Ended
	Jun. 30, 2018
Disclosure of accounting judgements and estimates [Abstract]
Significant Accounting Estimates And Assumptions	3. SIGNIFICANT ACCOUNTING ESTIMATES AND ASSUMPTIONS In the application of the Group’s accounting policies to the interim financial statements, management is required to make judgments, estimates and assumptions about the carrying amounts of assets and liabilities that are not readily apparent from other sources. Actual results can differ from those estimates based on such definitions. The significant judgments which management has made about the application of the Group’s accounting policies and key sources of uncertainty in estimate do not differ from those used in preparing the consolidated financial statements for the year ended December 31, 2017, except the Group’s policy, accounting estimates and assumptions described below; (1) Income taxes The Group is operating in numerous countries and the income generated from these operations is subject to income taxes based on tax laws and interpretations of tax authorities in numerous jurisdictions. There are many transactions and calculations which makes the ultimate tax determination uncertain. If certain portion of the taxable income is not used for investments, increase in wages, and others in accordance with the Tax System for Promotion of investment and Collaborative Cooperation (Recirculation of Corporate Income), the Group is liable to pay additional income tax calculated based on the tax laws. The new tax system is effective for three years from 2018. Accordingly, the measurement of current and deferred income tax is affected by the tax effects from the new system. As the Group’s income tax is dependent on the investments, increase in wages, and others, there exists uncertainty with regard to measuring the final tax effects. (2) Provisions for credit losses (allowances for loan losses, provisions for acceptances and guarantees, and unused loan commitments) In accordance with IFRS 9, the Group tests impairment and recognizes allowances for losses on financial assets classified at amortized cost, and debt instruments measured at fair value through other comprehensive income and lease receivables through impairment testing and recognizes provisions for guarantees, and unused loan commitments. Accuracy of provisions for credit losses is dependent upon estimation of expected cash flows of the borrower for individually assessed allowances of loans, and upon assumptions and methodology used for collectively assessed allowances for the Group’s of loans, guarantees and unused loan commitments.

Risk management

Risk management	6 Months Ended
	Jun. 30, 2018
Disclosure of risk management [Abstract]
Disclosure of risk management	4. RISK MANAGEMENT The Group’s operating activity is exposed to various financial risks. The Group is required to analyze and assess the level of complex risks, and determine the permissible level of risks and manage such risks. The Group’s risk management procedures have been established to improve the quality of assets for holding or investment purposes by making decisions as how to avoid or mitigate risks through the identification of the source of the potential risks and their impact. The Group has established an approach to manage the acceptable level of risks and reduce the excessive risks in financial instruments in order to maximize the profit given risks present, for which the Group has implemented processes for risk identification, assessment, control, and monitoring and reporting. The risk is managed by the risk management department in accordance with the Group’s risk management policy. The Risk Management Committee makes decisions on the risk strategies such as the allocation of risk capital and the establishment of acceptable level of risk. (1) Credit risk Credit risk represents the possibility of financial losses incurred when the counterparty fails to fulfill its contractual obligations. The goal of credit risk management is to maintain the Group’s credit risk exposure to a permissible degree and to optimize its rate of return considering such credit risk. 1) Credit risk management The Group considers the probability of failure in performing the obligation of its counterparties, credit exposure to the counterparty, the related default risk and the rate of default loss. The Group uses the credit rating model to assess the possibility of counterparty’s default risk; and when assessing the obligor’s credit grade, the Group utilizes credit grades derived using statistical methods. In order to manage credit risk limit, the Group establishes the appropriate credit line per obligor, company or industry. It monitors obligor’s credit line, total exposures and loan portfolios when approving the loan. The Group mitigates credit risk resulting from the obligor’s credit condition by using financial and physical collateral, guarantees, netting agreements and credit derivatives. The Group has adopted the entrapment method to mitigate its credit risk. Credit risk mitigation is reflected in qualifying financial collateral, trade receivables, guarantees, residential and commercial real estate and other collaterals. The Group regularly performs a revaluation of collateral reflecting such credit risk mitigation. 2) Maximum exposure to credit risk The Group’s maximum exposure to credit risk refers to net book value of financial assets net of allowances, which shows the uncertainties of maximum changes of net value of financial assets attributable to a particular risk without considering collateral and other credit enhancements obtained. However, the maximum exposure is the fair value amount (recorded on the books) for derivatives, maximum contractual obligation for payment guarantees and unused commitment. The maximum exposure to credit risk is as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Loans and other financial assets at amortized cost Korean treasury and government agencies 17,912,135 — Banks 21,942,788 — Corporates 92,333,155 — Consumers 145,531,925 — Subtotal 277,720,003 — Loans and receivables Korean treasury and government agencies — 8,823,584 Banks — 26,845,309 Corporates — 90,570,551 Consumers — 140,866,760 Subtotal — 267,106,204 Financial assets at FVTPL (IFRS 9) Deposit 24,921 — Debt securities 1,993,851 — Loans and receivables 336,967 — Derivative assets 2,391,211 — Subtotal 4,746,950 — Financial assets at FVTPL (IAS 39) Deposit — 25,972 Debt securities — 2,644,333 Financial assets designated at FVTPL — 9,694 Derivative assets — 3,115,775 Subtotal — 5,795,774 Financial assets at FVTOCI Debt securities 13,738,829 — AFS financial assets Debt securities — 13,229,244 Securities at amortized cost Debt securities 17,702,129 — HTM financial assets Debt securities — 16,749,296 Derivative assets Derivative assets (hedging) 12,395 59,272 Off-balance Guarantees 12,372,573 12,859,715 Loan commitments 98,251,006 80,760,325 Subtotal 110,623,579 93,620,040 total 424,543,885 396,559,830 a) Credit risk exposure by geographical areas The following tables analyze credit risk exposure by geographical areas (Unit: Korean Won in millions): June 30, 2018 Korea China USA UK Japan Others (*) Total Loans and other financial assets at amortized cost 258,023,468 4,589,930 4,514,541 1,268,461 400,907 8,922,696 277,720,003 Securities at amortized cost 17,531,402 — 64,856 — — 105,871 17,702,129 Financial assets at FVTPL 4,493,256 6,077 — 147,242 — 100,375 4,746,950 Financial assets at FVTOCI 12,749,695 50,874 43,352 78,485 2,274 814,149 13,738,829 Derivative assets 7,450 — — 4,945 — — 12,395 Off-balance 108,052,029 928,841 175,050 70,503 31,216 1,365,940 110,623,579 Total 400,857,300 5,575,722 4,797,799 1,569,636 434,397 11,309,031 424,543,885 December 31, 2017 Korea China USA UK Japan Others (*) Total Loans and receivables 250,678,479 4,104,912 2,823,247 1,094,988 381,890 8,022,688 267,106,204 Financial assets at FVTPL 5,551,870 2,937 — 148,955 — 92,012 5,795,774 AFS debt securities 12,407,602 52,259 151,131 — — 618,252 13,229,244 HTM securities 16,606,692 — 63,732 — — 78,872 16,749,296 Derivative assets 16,590 — — 42,682 — — 59,272 Off-balance 91,603,852 529,193 172,570 66,974 25,039 1,222,412 93,620,040 Total 376,865,085 4,689,301 3,210,680 1,353,599 406,929 10,034,236 396,559,830 (*) Others consist of financial assets in Indonesia, Hong Kong, Singapore, and other countries. b) Credit risk exposure by industries The following tables analyze credit risk exposure by industries, which are service, manufacturing, finance and insurance, construction, individuals and others in accordance with the Korea Standard Industrial Classification Code (Unit: Korean Won in millions): June 30, 2018 Service Manufacturing Finance and Construction Individuals Others Total Loans and other financial assets at amortized cost 48,025,922 35,583,702 42,207,115 3,657,220 138,906,711 9,339,333 277,720,003 Securities at amortized cost 1,142,178 — 11,516,407 313,936 — 4,729,608 17,702,129 Financial assets at FVTPL 97,529 166,054 3,404,674 43,899 3,019 1,031,775 4,746,950 Financial assets at FVTOCI 434,389 54,445 9,020,012 214,549 — 4,015,434 13,738,829 Derivative assets — — 12,395 — — — 12,395 Off-balance 18,236,857 22,675,034 9,503,718 4,052,757 49,105,163 7,050,050 110,623,579 Total 67,936,875 58,479,235 75,664,321 8,282,361 188,014,893 26,166,200 424,543,885 December 31, 2017 Service Manufacturing Finance and Construction Individuals Others Total Loans and receivables 47,192,641 34,502,509 38,260,051 3,574,746 133,094,287 10,481,970 267,106,204 Financial assets at FVTPL 100,766 83,239 4,640,068 15,073 1,040 955,588 5,795,774 AFS debt securities 707,737 37,719 7,331,774 153,534 — 4,998,480 13,229,244 HTM securities 1,348,754 — 10,962,149 296,214 — 4,142,179 16,749,296 Derivative assets — — 59,272 — — — 59,272 Off-balance 16,892,926 21,427,378 9,841,379 3,842,479 36,928,554 4,687,324 93,620,040 Total 66,242,824 56,050,845 71,094,693 7,882,046 170,023,881 25,265,541 396,559,830 3) Credit risk exposure The allowance to be recognized under IFRS 9 is the amount of expected 12-month Stage 1 Stage 2 Stage 3 Credit risk has not significantly Credit risk has Credit has been Allowance for expected credit losses Expected 12-month credit losses: Expected lifetime credit losses: Expected credit losses due to 12-month Expected credit losses from all possible defaults during the expected lifetime of the financial instruments. (*) Credit risk may be considered to not have been significantly increased when credit risk is low at the reporting date. The Group has estimated the allowance for credit losses based on experience losses with taken account of forward-looking information. The probability of default and loss at given default per financial assets considering account type of borrowers, credit rate grade, portfolio are used in estimation of allowance for expected credit losses and those factors are reviewed periodically to reduce the difference of expected losses and actual losses. The Group also measures expected credit losses using supportive and reasonable macroeconomic indicators, such as economic growth rates, interest rates, and composite stock indices. The methods for the estimation of forward-looking are also regularly reviewed. The Group undertakes the following procedures in order to predict and apply the forward-looking economic information: - Development of a prediction model by analyzing the correlation between macroeconomic data and yearly default rate of corporate and retail exposures. - Calculation of predicted annual default rate by applying forward-looking economic information, which includes estimated macroeconomic indices provided by verified institutions such as Bank of Korea and National Assembly Budget Office, to the prediction model developed. - If the predicted default rate is above the applicable default rate of the current period, application of the increase in default rate as a form of adjustment coefficient to the forward-looking economic information, thereby adjusting the current period estimation. At the end of each period the Group evaluates whether there has been a significant increase in the credit risk since initial recognition. The Group is assessing the change in the risk of a default occurring over the expected life of the financial instruments instead of the change in the amount of expected credit losses. The Group distinguishes corporates/consumers exposures when determining significant increase in credit risk, and the applied methodology is as follows: Corporates exposure Consumers exposure Under precautionary in assets quality More than 30 days past due Watch grade in early warning system Significant change of borrower financial situation (Working capital deficiencies, Adverse opinion, Disclaimer of opinion) Significant decreases in credit ratings Under precautionary in assets quality More than 30 days past due Significant decreases in credit ratings At the end of each reporting period, the Group assesses whether there is a significant increase in credit risk at the end of the reporting period compared to its initial recognition. The Group uses credit ratings, asset soundness, early warning systems, and delinquency days to determine whether the credit risk has significantly increased. The financial assets are impaired if the following conditions are met; - The principal and interest of the loan has been overdue for more than 90 days due to the serious deterioration of the credit condition, - It is deemed that the borrowers will not pay any portion of the debts without actions of recourse such as the disposition of the collateral is not taken - Objective evidence of impairment of financial assets are identified The Group writes off assets when it is determined that the receivables are virtually impossible to collect. The Group determines which receivable to write-off a) Financial assets The maximum exposure to credit risk, except for financial assets at FVTPL and derivative asset is as follows (Unit: Korean Won in millions): June 30, 2018 Stage 1 Stage 2 Stage 3 Total Loss Total, net Collateral Above Less than a Above Less than a Loans and other financial assets at amortized cost 246,719,865 18,794,529 6,195,331 5,772,369 2,068,664 279,550,758 (1,830,755 ) 277,720,003 789,660 Korean treasury and government agencies 17,916,231 — — — — 17,916,231 (4,096 ) 17,912,135 — Banks 21,599,560 83,471 269,742 — 10,905 21,963,678 (20,890 ) 21,942,788 — Corporates 72,113,414 15,745,380 582,857 3,618,576 1,482,948 93,543,175 (1,210,020 ) 92,333,155 555,228 General business 42,620,870 6,674,237 510,663 1,681,120 1,231,634 52,718,524 (843,365 ) 51,875,159 405,304 Small- and medium-sized 25,012,286 8,491,759 72,194 1,766,232 222,804 35,565,275 (327,323 ) 35,237,952 130,181 Project financing and others 4,480,258 579,384 — 171,224 28,510 5,259,376 (39,332 ) 5,220,044 19,743 June 30, 2018 Stage 1 Stage 2 Stage 3 Total Loss Total, net Collateral Above Less than a Above Less than a Consumers 135,090,660 2,965,678 5,342,732 2,153,793 574,811 146,127,674 (595,749 ) 145,531,925 234,432 Securities at amortized cost 17,707,379 — — — — 17,707,379 (5,250 ) 17,702,129 — Financial assets at FVTOCI (*3) 13,675,528 48,126 15,175 — — 13,738,829 (4,670 ) 13,738,829 — Total 278,102,772 18,842,655 6,210,506 5,772,369 2,068,664 310,996,966 (1,840,675 ) 309,160,961 789,660 (*1) Credit grade of corporates are AAA ~ BBB, and consumers are grades 1 ~ 6. (*2) Credit grade of corporates are BBB- (*3) Financial assets at FVTOCI have not been disclosed as the amount before deducting provisions because the carrying amount does not decrease. - Loans and receivables December 31, 2017 Corporates Korean Banks General Small and Project Subtotal Consumers Total Loans and receivables neither overdue nor impaired 8,825,767 26,861,286 50,463,112 34,107,547 5,547,950 90,118,609 139,886,407 265,692,069 Loans and receivables overdue but not impaired 8 — 65,616 63,067 — 128,683 878,406 1,007,097 Impaired loans and receivables — — 1,402,131 251,431 46,717 1,700,279 537,001 2,237,280 Total 8,825,775 26,861,286 51,930,859 34,422,045 5,594,667 91,947,571 141,301,814 268,936,446 Allowance for credit losses 2,191 15,977 1,078,733 267,162 31,125 1,377,020 435,054 1,830,242 Total, net 8,823,584 26,845,309 50,852,126 34,154,883 5,563,542 90,570,551 140,866,760 267,106,204 - Debt securities The Group manages debt securities based on the external credit rating. Credit soundness of debt securities on the basis of External Credit Assessment Institution (ECAI)’s rating is as follows (Unit: Korean Won in millions): December 31, 2017 Financial assets at AFS debt HTM securities Total AAA 1,685,099 9,897,689 15,806,327 27,389,115 AA- 722,923 2,386,567 888,547 3,998,037 BBB- 236,311 876,482 52,188 1,164,981 Below BBB- 9,694 68,506 2,234 80,434 Total 2,654,027 13,229,244 16,749,296 32,632,567 (*) Financial assets at FVTPL comprise debt securities held for trading and financial assets designated at FVTPL b) Guarantees and loan commitments The credit quality of the guarantees and loan commitments as of June 30, 2018 as follows (Unit: Korean Won in millions): June 30, 2018 Financial assets Stage 1 Stage 2 Stage 3 Total Above Less than a Above Less than a Off-balance 10,684,154 1,104,097 12,464 390,253 181,605 12,372,573 Loan commitments 92,335,107 3,717,790 1,455,884 740,283 1,942 98,251,006 Total 103,019,261 4,821,887 1,468,348 1,130,536 183,547 110,623,579 (*1) Credit grade of corporates are AAA ~ BBB, and consumers are grades 1 ~ 6. (*2) Credit grade of corporate are BBB- 4) Collateral and other credit enhancements There have been no significant changes in the value of collateral or other credit enhancements held by the Group during the current quarter, changes in collateral or other credit enhancements due to changes in the collateral policy of the Group. As of June 30, 2018, there are no financial assets that do not recognize the allowance for losses due to collateral. (2) Market risk Market risk is the possible risk of loss arising from trading activities and non-trading 1) Market risk management For trading activities and non-trading On a yearly basis, the Risk Management Committee establishes a Value at Risk (“VaR”, maximum losses) limit, loss limit and risk capital limit by subsidiaries for its management purposes. The limit by investment desk/dealer is independently managed to the extent of the limit given to subsidiaries and the limit by investment and loss cut is managed by the risk management personnel within the department. The Group uses both a standard-based and an internal model-based approach to measure market risk. The standard-based approach is used to calculate individual market risk of owned capital while the internal model-based approach is used to calculate general capital market risk and it is used to measure internal risk management measure. For the trading activities, the Risk Management department measures the VaR limit by department, risk factor and loss limit on a daily basis and reports regularly to the Risk Management Committee. 2) Sensitivity analysis of market risk The Group performs the sensitivity analyses both for trading and for non-trading For trading activities, the Group uses a VaR model that uses certain assumptions of possible fluctuations in market condition and, by conducting simulations of gains and losses, under which the model estimates the maximum losses that may occur. A VaR model predicts based on statistics of possible losses on the portfolio at a certain period currently or in the future. It indicates the maximum expected loss with at least 99% confidence level. In short, there exists a one percent possibility that the actual loss might exceed the predicted loss generated from the VaR calculation. The actual results are periodically monitored to examine the validity of the assumptions, variables, and factors that are used in VaR calculations. However, this approach cannot prevent the loss when the market fluctuation exceeds expectation. For the non-trading NII is a profit-based indicator for displaying the profit changes in short term due to the short-term interest changes. It will be estimated as subtracting interest expenses of liabilities from the interest income of assets. NPV is an indicator for displaying risks in economic view according to unfavorable changes related to interest rate. It will be estimated as subtracting the present value of liabilities from the present value of assets. EaR shows the maximum profit-loss amount, which indicates the maximum deduction amount caused by the unfavorable changes related to the interest rate of a certain period (i.e. 1 year). Interest rate VaR shows the potential maximum loss generated by the unfavorable changes during a certain period of time in the present or future. a) Trading activities The minimum, maximum and average VaR for the six months ended June 30, 2018 and for the year ended December 31, 2017, respectively, and the VaR as of June 30, 2018 and December 31, 2017, respectively, are as follows (Unit: Korean Won in millions): As of For the six months ended As of For the year ended Risk factor Average Maximum Minimum Average Maximum Minimum Interest rate 2,179 3,787 4,992 1,730 4,183 3,799 4,918 2,467 Stock price 2,872 2,524 4,618 1,138 909 2,863 4,419 909 Foreign currencies 4,224 4,853 6,136 3,695 4,750 5,051 6,636 4,061 Commodity price 2 1 4 — — 31 188 — Diversification (4,095 ) (4,745 ) (7,136 ) (1,749 ) (4,472 ) (4,621 ) (6,798 ) (2,067 ) Total VaR(*) 5,182 6,420 8,614 4,814 5,370 7,123 9,363 5,370 (*) VaR : Maximum losses b) Non-trading The NII and NPV are calculated for the assets and liabilities owned by the Bank and consolidated trusts, respectively, by using the simulation method. The scenario responding to interest rate (“IR”) changes are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 NII(*1) NPV(*2) NII(*1) NPV(*2) Base case 4,497,407 23,856,916 4,916,138 23,472,792 Base case (Prepay) 4,491,363 23,546,002 4,916,015 23,163,942 IR 100bp up 5,022,303 23,803,250 5,361,546 22,886,122 IR 100bp down 4,051,601 23,933,844 4,386,437 24,127,559 IR 200bp up 5,992,145 23,766,488 5,806,723 22,372,208 IR 200bp down 3,672,050 24,043,703 3,452,590 24,830,482 IR 300bp up 6,848,435 23,742,304 6,251,897 21,929,189 IR 300bp down 3,527,210 24,201,770 2,254,609 26,633,807 (*1) NII: Net Interest Income (*2) NPV: Net Portfolio Value The interest EaR and VaR calculated based on the BIS Framework of subsidiaries other than the Bank and consolidated trusts are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 EaR (*1) VaR (*2) EaR (*1) VaR (*2) 209,621 148,818 255,679 130,821 (*1) EaR: Earning at Risk (*2) VaR: Value at Risk The Group estimates and manages risks related to changes in interest rate due to the difference in the maturities of interest-bearing assets and liabilities and discrepancies in the terms of interest rates. Cash flows (both principal and interest) from non-trading, re-pricing June 30, 2018 Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over 5 Total Asset: Loans and other financial assets at amortized cost 148,324,408 41,273,662 9,372,945 8,650,081 47,212,644 4,314,787 259,148,527 Financial assets at FVTOCI 6,771,707 3,243,204 1,902,718 1,637,346 5,246,163 180,998 18,982,136 Securities at amortized cost 2,350,831 1,983,421 1,725,286 2,005,103 9,955,809 350,744 18,371,194 Total 157,446,946 46,500,287 13,000,949 12,292,530 62,414,616 4,846,529 296,501,857 Liability: Deposits due to customers 101,367,145 48,458,377 29,955,015 19,029,698 38,912,199 296,042 238,018,476 Borrowings 9,390,749 2,020,828 859,698 513,068 2,823,334 523,418 16,131,095 Debentures 979,221 1,801,149 2,183,459 2,407,879 18,625,611 2,727,547 28,724,866 Total 111,737,115 52,280,354 32,998,172 21,950,645 60,361,144 3,547,007 282,874,437 December 31, 2017 Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over 5 Total Asset: Loans and receivables 161,653,892 41,671,530 7,614,159 6,411,841 54,150,998 26,272,958 297,775,378 AFS financial assets 2,150,708 2,500,103 2,016,711 2,367,762 4,229,000 601,735 13,866,019 HTM financial assets 2,286,179 2,161,467 1,433,425 1,687,362 9,369,794 345,868 17,284,095 Total 166,090,779 46,333,100 11,064,295 10,466,965 67,749,792 27,220,561 328,925,492 Liability: Deposits due to customers 106,815,564 37,750,367 25,117,556 27,585,458 37,518,878 91,246 234,879,069 Borrowings 9,865,249 1,056,579 412,966 437,431 2,709,010 479,827 14,961,062 Debentures 1,955,902 2,452,240 1,018,563 1,752,847 19,770,538 2,869,766 29,819,856 Total 118,636,715 41,259,186 26,549,085 29,775,736 59,998,426 3,440,839 279,659,987 3) Currency risk Currency risk arises from the financial instruments denominated in foreign currencies other than the functional currency. Therefore, no currency risk arises from non-monetary Financial instruments in foreign currencies exposed to currency risk are as follows (Unit: USD in millions, JPY in millions, CNY in millions, EUR in millions, and Korean Won in millions): June 30, 2018 USD JPY CNY EUR Others Total Foreign Korean Foreign Korean Foreign Korean Foreign Korean Korean Korean Asset Loans and other financial assets at amortized cost 24,664 27,694,163 135,138 1,371,362 31,972 5,416,294 1,172 1,520,044 4,472,890 40,474,753 Financial assets at FVTPL 84 94,261 359 3,645 — — 36 46,488 75,122 219,516 Financial assets at FVTOCI 1,726 1,936,385 — — 300 50,874 — — 338,214 2,325,473 Securities at amortized cost 115 129,245 — — — — — — 105,949 235,194 Total 26,589 29,854,054 135,497 1,375,007 32,272 5,467,168 1,208 1,566,532 4,992,175 43,254,936 Liability Financial liabilities at FVTPL 63 70,963 505 5,127 — — 33 43,070 102,226 221,386 Deposits due to customer 11,160 12,517,349 145,058 1,472,035 21,633 3,664,842 1,230 1,595,651 2,700,164 21,950,041 Borrowings 6,417 7,201,536 2,211 22,438 — — 232 303,001 476,871 8,003,846 Debentures 3,708 4,159,175 — — — — — — 284,293 4,443,468 Other financial liabilities 3,240 3,633,942 23,541 238,890 5,568 943,321 140 182,002 4,602 5,002,757 Total 24,588 27,582,965 171,315 1,738,490 27,201 4,608,163 1,635 2,123,724 3,568,156 39,621,498 Off-balance 6,374 7,149,273 32,887 333,730 4,804 813,812 453 587,615 827,004 9,711,434 December 31, 2017 USD JPY CNY EUR Others Total Foreign Korean Foreign Korean Foreign Korean Foreign Korean Korean Korean Asset Loans and receivables 23,000 24,642,900 126,944 1,204,843 25,224 4,127,936 1,156 1,479,351 3,937,733 35,392,763 Financial assets at FVTPL 32 34,303 25 238 — — 27 34,583 104,892 174,016 AFS financial assets 1,966 2,105,972 — — 319 52,259 — 590 302,801 2,461,622 HTM financial assets 111 118,868 — — — — — — 78,175 197,043 Total 25,109 26,902,043 126,969 1,205,081 25,543 4,180,195 1,183 1,514,524 4,423,601 38,225,444 Liability Financial liabilities at FVTPL 41 43,423 79 752 — — 19 24,878 69,977 139,030 Deposits due to customer 13,744 14,725,686 195,176 1,852,440 21,865 3,578,142 883 1,129,802 2,396,826 23,682,896 Borrowings 6,604 7,080,118 2,218 21,056 — — 247 315,685 242,874 7,659,733 Debentures 3,467 3,714,411 — — 700 114,555 — — 375,749 4,204,715 Other financial liabilities 2,392 2,562,740 16,125 153,043 1,802 294,950 129 165,189 588,625 3,764,547 Total 26,248 28,126,378 213,598 2,027,291 24,367 3,987,647 1,278 1,635,554 3,674,051 39,450,921 Off-balance 8,108 8,687,009 33,624 319,127 1,199 196,261 406 519,843 176,886 9,899,126 (3) Liquidity risk Liquidity risk refers to the risk that the Group may encounter difficulties in meeting obligations from its financial liabilities. 1) Liquidity risk management Liquidity risk management is to prevent potential cash shortages as a result of mismatching the use of funds (assets) and sources of funds (liabilities) or unexpected cash outflows. The financial liabilities that are relevant to liquidity risk are incorporated within the scope of risk management. Derivatives instruments are excluded from those financial liabilities as they reflect expected cash flows for a pre-determined Assets and liabilities are grouped by account under Asset Liability Management (“ALM”) in accordance with the characteristics of the account. The Group manages liquidity risk by identifying the maturity gap and such gap ratio through various cash flows analysis (i.e. based on remaining maturity and contract period, etc.), while maintaining the gap ratio at or below the target limit. 2) Maturity analysis of non-derivative a) Cash flows of principals and interests by remaining contractual maturities of non-derivative June 30, 2018 Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over Total Financial liabilities at FVTPL 176,097 — — — — — 176,097 Deposits due to customers 145,033,422 38,505,386 22,976,591 24,574,059 7,487,432 2,144,802 240,721,692 Borrowings 6,407,137 2,639,064 1,876,893 1,478,115 3,238,353 545,403 16,184,965 Debentures 979,221 1,801,149 2,183,459 2,407,879 18,626,696 2,726,462 28,724,866 Other financial liabilities 14,098,508 216,627 3,644 908 621,127 1,955,992 16,896,806 Total 166,694,385 43,162,226 27,040,587 28,460,961 29,973,608 7,372,659 302,704,426 December 31, 2017 Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over Total Financial liabilities at FVTPL 168,442 155,984 1,717 512 375 — 327,030 Deposits due to customers 148,008,777 29,563,310 18,175,348 32,468,110 7,409,118 2,624,594 238,249,257 Borrowings 6,115,732 1,893,173 1,489,272 1,178,107 3,924,681 479,568 15,080,533 Debentures 1,955,255 2,452,565 1,018,714 1,744,731 19,770,380 2,869,699 29,811,344 Other financial liabilities 7,121,342 162,871 825 1,003 128,940 2,730,001 10,144,982 Total 163,369,548 34,227,903 20,685,876 35,392,463 31,233,494 8,703,862 293,613,146 b) Cash flows of principals and interests by expected maturities of non-derivative June 30, 2018 Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over 5 Total Financial liabilities at FVTPL 176,097 — — — — — 176,097 Deposits due to customers 154,934,637 40,340,567 20,220,152 18,154,029 6,115,894 348,774 240,114,053 Borrowings 6,407,137 2,639,064 1,876,893 1,478,115 3,242,839 540,917 16,184,965 Debentures 979,221 1,801,149 2,183,459 2,407,879 18,626,696 2,726,462 28,724,866 Other financial liabilities 14,098,508 216,627 3,644 908 621,127 1,955,992 16,896,806 Total 176,595,600 44,997,407 24,284,148 22,040,931 28,606,556 5,572,145 302,096,787 December 31, 2017 Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over 5 Total Financial liabilities at FVTPL 168,442 155,984 1,717 512 375 — 327,030 Deposits due to customers 159,146,602 31,298,562 16,667,130 21,995,294 6,487,047 2,278,756 237,873,391 Borrowings 6,115,732 1,893,173 1,489,272 1,178,107 3,924,681 479,568 15,080,533 Debentures 1,955,255 2,452,565 1,018,714 1,744,731 19,770,380 2,869,699 29,811,344 Other financial liabilities 7,121,342 162,871 825 1,003 128,940 2,730,001 10,144,982 Total 174,507,373 35,963,155 19,177,658 24,919,647 30,311,423 8,358,024 293,237,280 3) Maturity analysis of derivative financial liabilities Derivatives held for trading purpose are not managed in accordance with their contractual maturity, since the Group holds such financial instruments with the purpose of disposing or redemption before their maturity. As such, those derivatives are incorporated as “within 3 months” in the table below. Derivatives held for hedging purpose are estimated by offsetting cash inflows and cash outflows. The cash flow by the maturity of derivative financial liabilities as of June 30, 2018 and December 31, 2017 is as follows (Unit: Korean Won in millions): Remaining maturity Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over 5 Total June 30, 2018 2,377,750 2,130 — — 59,820 5,555 2,445,255 December 31, 2017 3,150,149 — — 381 67,373 — 3,217,903 4) Maturity analysis of off-balance The Group provides guarantees on behalf of customers. A financial guarantee represents an irrevocable undertaking that the Group should meet a customer’s obligations to third parties if the customer fails to do so. Under a loan commitment, the Group agrees to make funds available to a customer in the future. Loan commitments that are usually for a specified term may persist or may be unconditionally cancellable, provided all conditions in the loan facility are satisfied or waived. Commitments to lend include commercial standby facilities and credit lines, liquidity facilities to commercial paper conduits and utilized overdraft facilities. The maximum limit to be paid by the Group in accordance with guarantees and loan commitment only applies to principal amounts. There are contractual maturities for financial guarantees, such as guarantees for debentures issued or loans, loan commitments, and other guarantees, however, under the terms of the guarantees and loan commitments, funds should be paid upon demand from the counterparty. Details of off-balance June 30, 2018 December 31, 2017 Guarantees 12,372,573 12,859,715 Loan commitments 98,251,005 80,760,325 (4) Operational risk The Group defines the operational risk that could cause a negative effect on capital resulting from inadequate internal process, labor work and systematic problem or external factors. 1) Operational risk management The Group has been running the operational risk management system under Basel II. The Group developed Advanced Measurement Approaches (“AMA”) to quantify required capital for operational risk. This system is used for reinforcement in foreign competitions, reducing the amount of risk capitals, managing the risk, and precaution for any unexpected occasions. This system has been tested by an independent third party, and this system approved by the Financial Supervisory Service. 2) Operational risk measurement To quantify required capital for operational risk, the Group applies AMA using internal and external loss data, business environment and internal control factors, and scenario analysis. For the operational risk management for its subsidiaries, the Group adopted the Basic Indicator Approach. (5) Capital management The Group complies with the standard of capital adequacy provided by financial regulatory authorities. The capital adequacy standard is based on Basel III of Basel Committee on Banking Supervision and Basel III was applied from the end of December, 2013. The capital adequacy ratio is calculated by dividing own capital by asset (weighted with a risk premium – risk weighted assets) based on the consolidated financial statements of the Group. According to the above regulations, the Group is required to meet the following new minimum requirements: Common Equity Tier 1 capital ratio of 7.13% and 6.25%, a minimum Tier 1 ratio of 8.63% and 7.75% and a minimum total regulatory capital of 10.63% and 9.75% as of June 30, 2018 and December 31, 2017, respectively. Details of the Group’s capital adequacy ratio as of June 30, 2018 and December 31, 2017 are as follows (Unit: Korean Won in millions): June 30, 2018 (*) December 31, 2017 Tier 1 capital 16,952,436 16,074,987 Other Tier 1 capital 2,748,005 3,041,664 Tier 2 capital 3,499,122 3,486,555 Total risk-adjusted capital 23,199,563 22,603,206 Risk-weighted assets for credit risk 139,868,803 134,767,711 Risk-weighted assets for market risk 2,292,979 2,316,938 Risk-weighted assets for operational risk 9,826,809 9,677,559 Total risk-weighted assets 151,988,591 146,762,208 Common Equity Tier 1 ratio 11.15 % 10.95 % Tier 1 capital ratio 12.96 % 13.03 % Total capital ratio 15.26 % 15.40 % (*) Capital adequacy ratio as of June 30, 2018 is t

Operating segments

Operating segments	6 Months Ended
	Jun. 30, 2018
Disclosure of operating segments [Abstract]
Operating Segments	5. OPERATING SEGMENTS In evaluating the results of the Group and allocating resources, the Group’s Chief Operation Decision Maker (“CODM”) utilizes the information per type of customers. This financial information of the segments is regularly reviewed by the CODM to make decisions about resources to be allocated to each segment and evaluate its performance. (1) Segment by type of customers The Group’s reporting segments comprise the following customers: consumer banking, corporate banking, investment banking, capital market, credit card market and headquarters and others. The reportable segments are classified based on the target customers for whom the service is being provided. • Consumer banking: Loans/deposits and financial services for retail and individual consumers, etc. • Corporate banking: Loans/deposits and export/import, financial services for corporations, etc. • Investment banking: Domestic/foreign investment, structured finance, M&A, equity & fund investment related business, venture advisory related tasks, real estate SOC development practices, etc. • Capital market: Fund management, investment in securities and derivatives, etc. • Credit card: Credit card, cash service and card loan, etc. • Headquarter and others: Segments that do not belong to above operating segments The details of operating income by each segment are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Consumer Corporate Investment Capital Credit cards Headquarters Subtotal Adjustments Total Net Interest income Interest income 1,703,521 1,638,747 74,670 5,687 323,443 747,596 4,493,664 149,752 4,643,416 Interest expense (499,830 ) (994,523 ) (92 ) — (75,716 ) (458,733 ) (2,028,894 ) 149,952 (1,878,942 ) Inter-segment (274,405 ) 323,139 (77,656 ) 10,259 — 18,663 — — — 929,286 967,363 (3,078 ) 15,946 247,727 307,526 2,464,770 299,704 2,764,474 Net non-interest Non-interest 405,145 432,262 137,031 4,765,167 605,165 516,766 6,861,536 (236,269 ) 6,625,267 Non-interest (127,357 ) (183,814 ) (40,188 ) (4,725,584 ) (562,210 ) (218,710 ) (5,857,863 ) (182,141 ) (6,040,004 ) Inter-segment 78,522 36,407 — — — (114,929 ) — — — 356,310 284,855 96,843 39,583 42,955 183,127 1,003,673 (418,410 ) 585,263 Other income (expense) Administrative expense (875,328 ) (403,216 ) (5,689 ) (7,852 ) (83,575 ) (327,244 ) (1,702,904 ) 135,566 (1,567,338 ) Reversal of allowance for credit loss and impairment losses due to credit loss (53,008 ) 109,283 52,244 (3,268 ) (113,960 ) 62,729 54,020 (28,704 ) 25,316 (928,336 ) (293,933 ) 46,555 (11,120 ) (197,535 ) (264,515 ) (1,648,884 ) 106,862 (1,542,022 ) Operating income (expenses) 357,260 958,285 140,320 44,409 93,147 226,138 1,819,559 (11,844 ) 1,807,715 Non-operating (9,889 ) 671 17,411 — (2,988 ) 17,615 22,820 (29,003 ) (6,183 ) Net income before income tax expense 347,371 958,956 157,731 44,409 90,159 243,753 1,842,379 (40,847 ) 1,801,532 Income tax expense (95,528 ) (260,186 ) (43,377 ) (12,212 ) (22,541 ) (52,320 ) (486,164 ) 948 (485,216 ) Net income 251,843 698,770 114,354 32,197 67,618 191,433 1,356,215 (39,899 ) 1,316,316 For the six months ended June 30, 2017 Consumer Corporate Investment Capital Credit cards Headquarters Subtotal Adjustments Total Net Interest income Interest income 1,539,729 1,456,198 72,232 8,938 288,648 668,644 4,034,389 155,195 4,189,584 Interest expense (480,814 ) (818,422 ) (126 ) — (65,600 ) (411,449 ) (1,776,411 ) 137,147 (1,639,264 ) Inter-segment (248,116 ) 229,029 (66,693 ) 8,324 — 77,456 — — — 810,799 866,805 5,413 17,262 223,048 334,651 2,257,978 292,342 2,550,320 Net non-interest Non-interest 424,214 333,646 212,107 4,991,598 566,107 1,129,696 7,657,368 (126,727 ) 7,530,641 Non-interest (146,630 ) (82,261 ) (121,238 ) (4,968,840 ) (520,469 ) (862,571 ) (6,702,009 ) (240,504 ) (6,942,513 ) Inter-segment 45,402 29,680 — — — (75,082 ) — — — 322,986 281,065 90,869 22,758 45,638 192,043 955,359 (367,231 ) 588,128 For the six months ended June 30, 2017 Consumer Corporate Investment Capital Credit Headquarters Subtotal Adjustments Total Other income (expense) General and administrative expense (869,732 ) (402,661 ) (5,696 ) (7,721 ) (77,909 ) (298,578 ) (1,662,297 ) 123,870 (1,538,427 ) Reversal of allowance for credit loss and impairment losses due to credit loss (45,964 ) (128,685 ) 31,311 22,135 (106,698 ) 152,836 (75,065 ) (40,728 ) (115,793 ) (915,696 ) (531,346 ) 25,615 14,414 (184,607 ) (145,742 ) (1,737,362 ) 83,142 (1,654,220 ) Operating income 218,089 616,524 121,897 54,434 84,079 380,952 1,475,975 8,253 1,484,228 Non-operating 8,862 (3,122 ) 22,581 — (2,399 ) (26,180 ) (258 ) (54,022 ) (54,280 ) Net income before income tax expense 226,951 613,402 144,478 54,434 81,680 354,772 1,475,717 (45,769 ) 1,429,948 Income tax expense (54,923 ) (139,138 ) (34,964 ) (13,173 ) (19,816 ) (50,841 ) (312,855 ) (8,078 ) (320,933 ) Net income 172,028 474,264 109,514 41,261 61,864 303,931 1,162,862 (53,847 ) 1,109,015 (2) Information on products and services The products of the Group are classified as interest-bearing products such as loans, deposits and debt securities and non-interest non-interest (3) Information on geographical areas Among the Group’s revenue (interest income and non-interest non-current non-current

Cash and cash equivalents

Cash and cash equivalents	6 Months Ended
	Jun. 30, 2018
Cash and cash equivalents [Abstract]
Cash And Cash Equivalents	6. CASH AND CASH EQUIVALENTS (1) Details of cash and cash equivalents are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Cash 1,889,739 2,009,363 Foreign currencies 795,692 617,155 Demand deposits 2,777,874 3,423,355 Fixed deposits 457,263 858,413 Total 5,920,568 6,908,286 (2) Significant transactions of investing activities and financing activities not involving cash inflows and outflows are as follows (Unit: Korean Won in millions): For the For the Changes in other comprehensive gain due to remeasurement of financial assets designated at FVTOCI 41,452 — Changes in other comprehensive loss due to valuation of AFS financial assets — (28,706 ) Changes in other comprehensive income of investment in associates 1,210 1,507 Changes in other comprehensive gain (loss) of foreign operations translation 35,526 (69,010 ) Changes in other comprehensive loss related to valuation of cash flow hedging (6,213 ) (1,526 ) Changes in other comprehensive loss due to remeasurement of the net defined benefit liability (59,573 ) (9,677 ) Changes in investments in associates due to debt-equity swap — 51,405 Changes in investments in associates due to accounts transfer (5,865 ) (16,354 ) Changes in accrued dividends of hybrid equity securities (80 ) (9,804 ) Changes in intangible assets related to accounts payable 32,369 (8,506 ) Classified to assets held for sale from premises and equipment 6,050 2,184

Financial assets at fair value

Financial assets at fair value through profit or loss	6 Months Ended
	Jun. 30, 2018
Financial assets at fair value through profit or loss [Abstract]
Disclosure of financial assets at fair value through profit or loss	7. FINANCIAL ASSETS AT FVTPL (1) Financial assets at FVTPL are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Financial assets at fair value through profit or loss mandatorily measured at fair value 6,340,704 — Financial assets held for trading — 5,820,787 Financial assets designated at FVTPL — 22,290 Total 6,340,704 5,843,077 (2) Financial assets at fair value through profit or loss mandatorily measured at fair value and financial assets held for trading are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Deposits: Gold banking asset 24,921 25,972 Securities: Debt securities Korean treasury and government agencies 639,476 540,438 Financial institutions 639,711 1,476,498 Corporates 714,508 627,397 Others 156 — June 30, 2018 December 31, 2017 Equity securities 433,316 21,666 Capital contributions 349,470 — Beneficiary certificates 810,968 13,041 Subtotal 3,587,605 2,679,040 Loans 336,967 — Derivatives assets 2,391,211 3,115,775 Total 6,340,704 5,820,787 (3) Financial assets at fair value through profit or loss designated as upon initial recognition as of June 30, 2018 and financial assets at fair value through profit or loss designated as upon initial recognition as of December 31, 2017 are as follows (Unit: Korean Won in millions): December 31, 2017 Debt securities 9,694 Equity securities 12,596 Total 22,290

Financial assets at fair valu13

Financial assets at fair value through other comprehensive income and available for sale financial assets	6 Months Ended
	Jun. 30, 2018
Financial assets at fair falue through other comprehensive income and available-for-sale financial assets [Abstract]
Financial assets at fair value through other comprehensive income and available-for-sale assets explanatory	8. FINANCIAL ASSETS AT FVTOCI AND AFS FINANCIAL ASSETS (1) Details of financial assets at FVTOCI as of June 30, 2018 and AFS financial assets as of December 31, 2017 are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Debt securities: Korean treasury and government agencies 2,195,526 2,330,567 Financial institutions 7,370,107 5,217,266 Corporates 1,797,635 2,725,232 Asset-backed securities — 308,181 Bond denominated in foreign currencies 2,325,422 2,442,579 Others — 35,163 Subtotal 13,688,690 13,058,988 Equity securities 905,779 1,411,078 Beneficiary certificates — 712,628 Securities loaned 50,139 170,256 Total 14,644,608 15,352,950 (2) Details of equity securities designated as financial assets at FVTOCI are as follows (Unit: Korean Won in millions): June 30, 2018 Purpose of acquisition Fair value Strategic business partnership 737,104 Debt-equity swap 168,533 Others(*) 142 Total 905,779 (*) Cooperate insurance, etc. (3) Changes in the loss allowance and gross carrying amount of financial assets at FVTOCI are as follows (Unit: Korean Won in millions): 1) Loss allowance For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance (*1) (4,107 ) (129 ) — (4,236 ) Transfer to 12-month — — — — Transfer to lifetime expected credit losses — — — — Transfer to credit-impaired financial assets — — — — Net reversal (provision) of loss allowance (562 ) 103 — (459 ) Disposal 27 — — 27 Others (*2) (2 ) — — (2 ) Ending balance (4,644 ) (26 ) — (4,670 ) (*1) The beginning balance was restated in accordance with IFRS 9. (*2) Others consist of foreign currencies translation, etc. 2) Gross carrying amount For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance 12,843,997 30,212 — 12,874,209 Transfer to 12-month — — — — Transfer to lifetime expected credit losses — — — — Transfer to credit-impaired financial assets — — — — Acquisition 5,075,597 — — 5,075,597 Disposal (4,294,135 ) (15,047 ) — (4,309,182 ) Gain (loss) on valuation 12,874 10 — 12,884 Amortization on the effective interest method (2,289 ) — — (2,289 ) Others (*) 87,610 — — 87,610 Ending balance 13,723,654 15,175 — 13,738,829 (*) Others consist of foreign currencies translation, etc. (4) The Group disposed equity securities designated as financial assets at FVTOCI in accordance with the resolution of disposal from the creditors’ council for the six months ended June 30, 2018. The fair value and accumulative loss on valuation of that equity securities at disposal date are 3,974 million Won and 424 million Won, respectively.

Securities at amortized cost an

Securities at amortized cost and held to maturity financial assets	6 Months Ended
	Jun. 30, 2018
Disclosure of securities at amortised cost and held to maturity financial assets [Abstract]
Securities at amortised cost and held to maturity financial assets	9. SECURITIES AT AMORTIZED COST AND HTM FINANCIAL ASSETS (1) Details of securities at amortized cost as of June 30, 2018 and HTM financial assets as of December 31, 2017 are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Korean treasury and government agencies 4,630,598 3,994,857 Financial institutions 7,767,490 7,245,426 Corporates 5,074,097 5,311,970 Bond denominated in foreign currencies 235,194 197,043 Loss allowance (5,250 ) — Total 17,702,129 16,749,296 (2) Changes in the loss allowance and gross carrying amount of securities at amortized cost are as follows (Unit: Korean Won in millions): 1) Loss allowance For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance (*1) (5,078 ) — — (5,078 ) Transfer to 12-month — — — — Transfer to lifetime expected credit losses — — — — Transfer to credit-impaired financial assets — — — — Net provision of loss allowance (191 ) — — (191 ) Disposal 22 — — 22 Others (*2) (3 ) — — (3 ) Ending balance (5,250 ) — — (5,250 ) (*1) The beginning balance was restated in accordance with IFRS 9. (*2) Others consist of foreign currencies translation, etc. 2) Gross carrying amount For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance 16,749,296 — — 16,749,296 Transfer to 12-month — — — — Transfer to lifetime expected credit losses — — — — Transfer to credit-impaired financial assets — — — — Acquisition 5,829,462 — — 5,829,462 Disposal / Redemption (4,873,896 ) — — (4,873,896 ) Amortization on the effective interest method (6,008 ) — — (6,008 ) Others (*) 8,525 — — 8,525 Ending balance 17,707,379 — — 17,707,379 (*) Others consist of foreign currencies translation, etc.

Loans and other financial asset

Loans and other financial assets at amortized cost and loans and receivables	6 Months Ended
	Jun. 30, 2018
Disclosure of loans and other financial assets at amortized cost and loans and receivables [Abstract]
Loans and other financial assets at amortized cost and loans and receivables	10. LOANS AND OTHER FINANCIAL ASSETS AT AMORTIZED COST, AND LOANS AND RECEIVABLES (1) Details of loans and other financial assets at amortized cost as of June 30, 2018 and loans and receivables as of December 31, 2017 are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Due from banks 17,770,356 8,868,378 Loans 248,794,014 251,523,301 Other financial assets (other receivables) 11,155,633 6,714,525 Total 277,720,003 267,106,204 (2) Details of due from banks are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Due from banks in local currency: Due from The Bank of Korea (“BOK”) 14,500,746 6,246,496 Due from depository banks 90,003 30,003 Due from non-depository 33 150 Due from the Korea Exchange — 50,000 Others 68,132 97,365 Loss allowance (3,475 ) (1,541 ) Subtotal 14,655,439 6,422,473 Due from banks in foreign currencies: Due from banks on demand 1,055,513 794,353 Due from banks on time 1,237,312 972,915 Others 824,229 679,554 Loss allowance (2,137 ) (917 ) Subtotal 3,114,917 2,445,905 Total 17,770,356 8,868,378 (3) Details of restricted due from banks are as follows (Unit: Korean Won in millions): Counterparty June 30, 2018 Reason of restriction Due from banks in local currency: Due from BOK The BOK 14,500,746 Reserve deposits under the BOK Act Others The Korea Exchange and others 64,150 Central counterparty KRW margin and others Subtotal 14,564,896 Due from banks in foreign currencies: Due from banks on demand The BOK and others 1,048,609 Reserve deposits under the BOK Act and others Others The People’s Bank of China and others 824,229 Reserve deposits and others Due from banks on time National Bank of Cambodia 56 Fast And Secure Transfer (Payment system) Subtotal 1,872,894 Total 16,437,790 Counterparty December 31, 2017 Reason of restriction Due from banks in local currency: Due from BOK The BOK 6,246,496 Reserve deposits under the BOK Act Others The Korea Exchange and others 94,394 Central counterparty KRW margin and others Subtotal 6,340,890 Counterparty December 31, 2017 Reason of restriction Due from banks in foreign currencies: Due from banks on demand The BOK and others 787,520 Reserve deposits under the BOK Act and others Others The People’s Bank of China and others 367,108 Reserve deposits and others Subtotal 1,154,628 Total 7,495,518 (4) Changes in the loss allowance and gross carrying amount of due from banks are as follows (Unit: Korean Won in millions): 1) Loss allowance For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance (*1) (3,092 ) — — (3,092 ) Transfer to 12-month — — — — Transfer to lifetime expected credit losses — — — — Transfer to credit-impaired financial assets — — — — Net provision of loss allowance (2,500 ) — — (2,500 ) Others (*2) (20 ) — — (20 ) Ending balance (5,612 ) — — (5,612 ) (*1) The beginning balance was restated in accordance with IFRS 9. (*2) Others consist of foreign currencies translation and etc. 2) Gross carrying amount For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance 8,870,835 — — 8,870,835 Transfer to 12-month — — — — Transfer to lifetime expected credit losses — — — — Transfer to credit-impaired financial assets — — — — Net increase 8,855,041 — — 8,855,041 Others (*) 50,092 — — 50,092 Ending balance 17,775,968 — — 17,775,968 (*) Others consist of foreign currencies translation and etc. (5) Details of loans are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Loans in local currency 204,830,133 200,213,230 Loans in foreign currencies 14,731,407 13,147,888 Domestic banker’s letter of credit 3,074,011 2,516,907 Credit card accounts 7,570,281 6,827,295 Bills bought in foreign currencies 6,830,374 8,197,159 Bills bought in local currency 257,405 334,714 Factoring receivables 61,382 137,523 June 30, 2018 December 31, 2017 Advances for customers on guarantees 14,910 23,620 Private placement bonds 433,591 362,319 Securitized loans 1,228,212 563,152 Call loans 3,135,670 3,003,455 Bonds purchased under resale agreements 6,999,881 16,859,064 Loan origination costs and fees 545,864 510,860 Others 836,266 607,325 Discounted present value (5,068 ) (10,988 ) Loss allowance (1,750,305 ) (1,770,222 ) Total 248,794,014 251,523,301 (6) Changes in the loss allowance on loans for the six months ended June 30, 2018 are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Consumers Corporates Stage 1 Stage 2 Stage 3 Stage 1 Stage 2 Stage 3 Beginning balance (*1) (101,479 ) (41,358 ) (117,168 ) (365,246 ) (255,926 ) (905,243 ) Transfer to 12-month (9,219 ) 8,797 421 (20,913 ) 20,634 280 Transfer to lifetime expected credit losses 6,076 (7,514 ) 1,438 17,263 (106,963 ) 89,700 Transfer to credit-impaired financial assets 19,177 23,228 (42,406 ) 2,976 12,016 (14,991 ) Net reversal (provision) of loss allowance (22,903 ) (29,025 ) (51,219 ) (5,600 ) 30,121 154,111 Recoveries of loans previously charged off — — (23,392 ) — — (52,273 ) Charge-off — — 117,228 — — 121,847 Disposal — — 780 — 67 17,676 Unwinding effect — — 3,665 — — 12,961 Others (*2) (1,994 ) (39 ) (1,156 ) 23,916 (87 ) (312 ) Ending balance (110,342 ) (45,911 ) (111,809 ) (347,604 ) (300,138 ) (576,244 ) For the six months ended June 30, 2018 Credit card accounts Sub-total Stage 1 Stage 2 Stage 3 Stage 1 Stage 2 Stage 3 Beginning balance (*1) (57,134 ) (71,463 ) (102,858 ) (523,859 ) (368,747 ) (1,125,269 ) Transfer to 12-month (12,969 ) 12,880 89 (43,101 ) 42,311 790 Transfer to lifetime expected credit losses 6,963 (7,307 ) 344 30,302 (121,784 ) 91,482 Transfer to credit-impaired financial assets 698 2,537 (3,235 ) 22,851 37,781 (60,632 ) Net reversal (provision) of loss allowance (409 ) (11,715 ) (90,448 ) (28,912 ) (10,619 ) 12,444 Recoveries of loans previously charged off — — (28,706 ) — — (104,371 ) Charge-off — — 104,478 — — 343,553 Disposal — — — — 67 18,456 Unwinding effect — — — — — 16,626 Others (*2) (2 ) — — 21,920 (126 ) (1,468 ) Ending balance (62,853 ) (75,068 ) (120,336 ) (520,799 ) (421,117 ) (808,389 ) (*1) The beginning balance was restated in accordance with IFRS 9. (*2) Others consist of debt-equity swap, foreign currencies translation and etc. Changes in the loss allowances on loans and receivables for the six months ended June 30, 2017 are as follows (Unit: Korean Won in millions): For six months ended June 30, 2017 Consumers Corporates Credit card Others Total Beginning balance (163,858 ) (1,498,842 ) (155,372 ) (209,024 ) (2,027,096 ) Net reversal (provision) of loss allowance (65,582 ) (191,263 ) (91,022 ) 13,891 (333,976 ) Recoveries of loans previously charged off (21,659 ) (55,319 ) (24,808 ) (3 ) (101,789 ) Charge-off 67,593 220,598 104,195 51,260 443,646 Disposal 830 58,431 — 29,264 88,525 Unwinding effect 4,620 20,047 — — 24,667 Others (*) 416 179,068 — (633 ) 178,851 Ending balance (177,640 ) (1,267,280 ) (167,007 ) (115,245 ) (1,727,172 ) (*) Others consist of debt-equity swap, foreign currencies translation and etc. (7) Changes in the gross carrying amount of loans are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Consumers Corporates Stage 1 Stage 2 Stage 3 Stage 1 Stage 2 Stage 3 Beginning balance 103,502,347 5,487,758 326,739 130,561,786 5,000,966 1,622,410 Transfer to 12-month 1,772,982 (1,768,978 ) (4,004 ) 1,113,857 (1,112,533 ) (1,324 ) Transfer to lifetime expected credit losses (2,731,516 ) 2,746,818 (15,302 ) (2,112,755 ) 2,222,364 (109,609 ) Transfer to credit-impaired financial assets (84,885 ) (101,151 ) 186,036 (155,933 ) (118,707 ) 274,640 Charge-off — — (117,228 ) — — (121,847 ) Disposal — (270 ) (13,483 ) — (883 ) (67,695 ) Net increase (decrease) 2,913,765 (742,949 ) (22,980 ) (4,520,684 ) (688,875 ) (149,456 ) Ending balance 105,372,693 5,621,228 339,778 124,886,271 5,302,332 1,447,119 For the six months ended June 30, 2018 Credit card accounts Sub-total Stage 1 Stage 2 Stage 3 Stage 1 Stage 2 Stage 3 Beginning balance 5,721,743 935,266 177,983 239,785,876 11,423,990 2,127,132 Transfer to 12-month 243,044 (242,932 ) (112 ) 3,129,883 (3,124,443 ) (5,440 ) Transfer to lifetime expected credit losses (299,729 ) 300,190 (461 ) (5,144,000 ) 5,269,372 (125,372 ) Transfer to credit-impaired financial assets (27,288 ) (24,128 ) 51,416 (268,106 ) (243,986 ) 512,092 Charge-off — — (104,478 ) — — (343,553 ) Disposal — — — — (1,153 ) (81,178 ) Net increase (decrease) 722,640 46,551 75,193 (884,279 ) (1,385,273 ) (97,243 ) Ending balance 6,360,410 1,014,947 199,541 236,619,374 11,938,507 1,986,438 (8) Details of other financial assets (other receivables) are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 CMA accounts 200,000 135,000 Receivables 8,721,745 4,459,318 Accrued income 1,055,713 1,026,273 Telex and telephone subscription rights and refundable deposits 980,611 984,620 Other receivables 272,403 166,877 Loss allowance (74,839 ) (57,563 ) Total 11,155,633 6,714,525 (9) Changes in the loss allowances on other financial assets are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance (*) (2,955 ) (1,832 ) (54,211 ) (58,998 ) Transfer to 12-month (161 ) 146 15 — Transfer to lifetime expected credit losses 112 (122 ) 10 — Transfer to credit-impaired financial assets 23 167 (190 ) — Net provision of loss allowance (360 ) (256 ) (30,854 ) (31,470 ) Recoveries of other financial assets previously charged off — — (2 ) (2 ) Charge-off — — 15,225 15,225 Disposal — — 593 593 Others (208 ) — 21 (187 ) Ending balance (3,549 ) (1,897 ) (69,393 ) (74,839 ) (*) The beginning balance was restated in accordance with IFRS 9. (10) Changes in the gross carrying amount of other financial assets are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance 6,662,335 29,124 79,912 6,771,371 Transfer to 12-month 8,130 (8,109 ) (21 ) — Transfer to lifetime expected credit losses (10,935 ) 10,949 (14 ) — Transfer to credit-impaired financial assets (768 ) (1,120 ) 1,888 — Charge-off — — (15,225 ) (15,225 ) Disposal — (2 ) (735 ) (737 ) Net increase and others 4,460,291 (1,650 ) 16,422 4,475,063 Ending balance 11,119,053 29,192 82,227 11,230,472

Fair value of financial assets

Fair value of financial assets and liabilities	6 Months Ended
	Jun. 30, 2018
Disclosure of fair value measurement [Abstract]
The Fair Value Of Financial Assets And Liabilities	11. FAIR VALUE OF FINANCIAL ASSETS AND LIABILITIES (1) The fair value hierarchy The fair value hierarchy is determined by the levels of judgment involved in estimating fair values of financial assets and liabilities. The specific financial instruments characteristics and market condition such as volume of transactions and transparency are reflected to the market observable inputs. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities. The Group maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value of its financial assets and financial liabilities. Fair value is measured based on the perspective of a market participant. As such, even when market assumptions are not readily available, the Group’s own assumptions reflect those that market participants would use for measuring the assets or liabilities at the measurement date. The fair value measurement is described in the one of the following three levels used to classify fair value measurements: • Level 1—fair value measurements are those derived from quoted prices (unadjusted) in active markets for identical assets or liabilities. The types of financial assets or liabilities generally included in Level 1 are publicly traded equity securities, derivatives, and debt securities issued by governmental bodies. • Level 2—fair value measurements are those derived from inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly (i.e. prices) or indirectly (i.e. derived from prices). The types of financial assets or liabilities generally included in Level 2 are debt securities not traded in active markets and derivatives traded in OTC but not required significant judgment. • Level 3—fair value measurements are those derived from valuation technique that include inputs for the asset or liability that are not based on observable market data (unobservable inputs). The types of financial assets or liabilities generally included in Level 3 are non-public The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The Group’s assessment of the significance of a particular input to a fair value measurement in its entirety requires judgment and consideration of inherent factors of the asset or liability. (2) Fair value hierarchy of financial assets and liabilities measured at fair value are as follows (Unit: Korean Won in millions): June 30, 2018 Level 1 (*1) Level 2 (*1) Level 3 Total Financial assets: Financial assets at fair value through profit or loss mandatorily measured at fair value Deposits 24,921 — — 24,921 Debt securities 375,280 1,611,129 7,442 1,993,851 Equity securities 80,536 — 352,780 433,316 Capital contributions — — 349,470 349,470 Beneficiary certificates — 62,173 748,795 810,968 Loans — 85,000 251,967 336,967 Derivative assets 17,439 2,337,601 36,171 2,391,211 Subtotal 498,176 4,095,903 1,746,625 6,340,704 Financial assets at FVTOCI Debt securities 2,463,992 11,224,698 — 13,688,690 Equity securities 440,038 — 465,741 905,779 Securities loaned — 50,139 — 50,139 Subtotal 2,904,030 11,274,837 465,741 14,644,608 Derivative assets — 12,395 — 12,395 Total 3,402,206 15,383,135 2,212,366 20,997,707 June 30, 2018 Level 1 (*1) Level 2 (*1) Level 3 Total Financial liabilities: Financial liabilities at fair value through profit or loss mandatorily measured at fair value Deposits due to customers 24,485 — — 24,485 Derivative liabilities 3,269 2,333,558 40,923 2,377,750 Subtotal 27,754 2,333,558 40,923 2,402,235 Financial liabilities at fair value through profit or loss designated as upon initial recognition Equity-linked securities — — 176,097 176,097 Derivative liabilities — 67,505 — 67,505 Total 27,754 2,401,063 217,020 2,645,837 December 31, 2017 Level 1 (*1) Level 2 (*1) Level 3 (*2) Total Financial assets: Financial assets held for trading Deposits 25,972 — — 25,972 Debt securities 405,942 2,238,391 — 2,644,333 Equity securities 21,666 — — 21,666 Beneficiary certificates — 13,041 — 13,041 Derivative assets 1,021 3,093,272 21,482 3,115,775 Subtotal 454,601 5,344,704 21,482 5,820,787 Financial assets designated at FVTPL Debt securities — — 9,694 9,694 Equity securities — — 12,596 12,596 Subtotal — — 22,290 22,290 AFS financial assets Debt securities 2,710,172 10,348,816 — 13,058,988 Equity securities 399,214 — 1,011,864 1,411,078 Beneficiary certificates — 68,722 643,906 712,628 Securities loaned 69,778 100,478 — 170,256 Subtotal 3,179,164 10,518,016 1,655,770 15,352,950 Derivative assets — 59,272 — 59,272 Total 3,633,765 15,921,992 1,699,542 21,255,299 Financial liabilities: Financial liabilities held for trading Deposits due to customers 25,964 — — 25,964 Derivative liabilities 2,613 3,126,585 20,951 3,150,149 Subtotal 28,577 3,126,585 20,951 3,176,113 Financial liabilities designated at FVTPL Equity-linked securities — — 160,057 160,057 Debentures — 91,739 — 91,739 Subtotal — 91,739 160,057 251,796 Derivative liabilities — 67,754 — 67,754 Total 28,577 3,286,078 181,008 3,495,663 (*1) There were no transfers between Level 1 and Level 2 of financial assets and liabilities measured at fair value. The Group recognizes transfers among levels at the end of reporting period in which events have occurred or conditions have changed. (*2) Certain AFS unquoted equity securities were measured at cost as of December 31, 2017, that amounted to 37,092 million Won. These unquoted equity instruments mostly represent minority investments in structured entity vehicles, such as asset securitization structures. They are measured at cost because (a) observable inputs of financial information to measure fair value were not available to obtain, (b) there was a significant variance in likely estimated cash flows or (c) the probabilities for various estimated cash flows could not be measured reliably. In addition, the Group has no intention to dispose these investments in the foreseeable future. Financial assets and liabilities at fair value through profit or loss mandatorily measured at fair value, financial liabilities at fair value through profit or loss designated as upon initial recognition, financial assets at FVTOCI, and derivative assets and liabilities are recognized at fair value. Fair value is the amount that would be received to sell an asset, or paid to transfer a liability, in an orderly transaction between market participants at the measurement date. Financial instruments are measured at fair value using a quoted market price in active markets. If there is no active market for a financial instrument, the Group determines the fair value using valuation methods. Valuation methods and input variables for each type of financial instruments are as follows: Valuation methods Input variables Loans The fair value of Loans is measured by the Binomial tree given the values of underlying assets and volatility. Values of underlying assets, Volatility Debt securities The fair value is measured by discounting the projected cash flows of debt securities by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the issuers of the securities. Risk-free market rate, credit spread Equity securities, capital contribution and Beneficiary certificates Among DCF (Discounted Cash Flow) Model, FCFE (Free Cash Flow to Equity) Model, Comparable Company Analysis, Dividend Discount Model, Risk-adjusted Rate of Return Method, and Net Asset Value Method, more than one method is used given the characteristic of the subject of fair value measurement. Risk-free market rate, market risk premium, Beta, etc. Valuation methods Input variables Derivatives The in-house However, for some complicated financial instruments of which valuation should be based on some assumptions since some significant or all inputs to be used in the model are not observable in the market, the in-house Risk-free market rate, forward rate, volatility, foreign exchange rate, stock prices, etc. Equity-linked securities The fair value of security linked to stock prices or derivatives is measured by the models such as DCF model, FDM, or Monte Carlo Simulation given the natures of the securities or underlying assets. Values of underlying assets, risk-free market rate, market rate, dividend and convenience yield, volatility, correlation coefficient, credit spread, and foreign exchange rate Debentures The fair value is measured by discounting the projected cash flows of a debenture by applying the market discount rate that is reflecting credit rating of the Group. Risk-free market rate, forward rate Valuation methods of financial assets and liabilities measured at fair value and classified into Level 3 and significant but unobservable inputs are as follows: Fair value measurement Input variable Range Impact of changes in significant unobservable Loans Binomial tree Stock, Volatility of underlying asset 14.92% – 41.24% Variation of fair value increases as volatility increases. Derivative assets Option valuation model and others Correlation coefficient 0.900 – 0.970 Variation of fair value increases as correlation coefficient increases. Volatility of underlying asset 10.61% – 27.59% Variation of fair value increases as volatility increases. Derivative liabilities Option valuation model and others Correlation coefficient 0.900 – 0.970 Variation of fair value increases as correlation coefficient increases. Volatility of underlying asset 10.61% – 27.59% Variation of fair value increases as volatility increases. Equity-linked securities Monte Carlo Simulation and others Correlation coefficient 0.0861 – 0.688 Equity-linked securities’ variation of fair value increases if both volatility and correlation coefficient increase. However, when correlation coefficient decreases despite the increase in volatility, the variation of fair value of a compound financial instrument may decrease. Volatility of underlying asset 18.60% – 26.88% Equity securities and beneficiary certificates External appraisal value and others Expected growth rate 0.00% Fair value increases as expected growth rate increases. Discount rate 0.99% – 18.73% Fair value increases as discount rate decreases. Volatility of real estate sale price 0.00% Fair value increases as sale price increases. Fair value of financial assets and liabilities classified into Level 3 is measured by the Group using its own valuation methods or using external specialists. Unobservable inputs used in the fair value measurements are produced by the internal system of the Group and the appropriateness of inputs is reviewed regularly. (3) Changes in financial assets and liabilities measured at fair value classified into Level 3 are as follows (Unit: Korean Won in millions): For six months ended June 30, 2018 January 1, Net Other Purchases/ Disposals/ Transfer to June 30, Financial assets: Financial assets at fair value through profit or loss mandatorily measured at fair value Debt securities 9,694 (111 ) — — (2,141 ) — 7,442 Equity securities 280,171 22,834 — 50,005 (230 ) — 352,780 Capital contributions 294,121 21,934 — 49,367 (15,952 ) — 349,470 Beneficiary certificates 654,066 12,973 — 1,924,763 (1,843,007 ) — 748,795 Loans 165,001 3,616 — 125,807 (42,457 ) — 251,967 Derivative assets 19,346 65,856 — 1,936 (50,967 ) — 36,171 Subtotal 1,422,399 127,102 — 2,151,878 (1,954,754 ) — 1,746,625 Financial assets at FVTOCI Equity securities 451,287 (393 ) 14,557 290 — — 465,741 Total 1,873,686 126,709 14,557 2,152,168 (1,954,754 ) — 2,212,366 Financial liabilities: Financial liabilities at fair value through profit or loss mandatorily measured at fair value Derivative liabilities 20,951 73,951 — (3,058 ) (50,921 ) — 40,923 Financial liabilities at fair value through profit or loss designated as upon initial recognition Equity-linked securities 160,057 (1,438 ) — 179,044 (161,566 ) — 176,097 Total 181,008 72,513 — 175,986 (212,487 ) — 217,020 (*1) The losses that increase financial liabilities are presented as positive amounts, and the gains that decrease financial liabilities are presented as negative amounts. The gain amounting to 61,323 million Won for six months ended June 30, 2018, which is from financial assets and liabilities that the Group holds as at the end of the periods, has been recognized in net gain (loss) on financial assets at FVTPL and net gain (loss) on financial assets at FVTOCI in the consolidated statement of comprehensive income. (*2) The Group recognizes transfers between levels at the end of reporting period within which events have occurred or conditions have changed. For the six months ended June 30, 2017 January 1, Net Other Purchases/ Disposals/ Transfer to June 30, Financial assets: Financial assets held for trading Derivative assets 23,153 21,217 — 472 (17,420 ) — 27,422 Financial assets designed at FVTPL Debt securities 4,348 191 — 2,000 — — 6,539 Equity securities 12,652 (207 ) — — — — 12,445 Sub-total 17,000 (16 ) — 2,000 — — 18,984 For the six months ended June 30, 2017 January 1, Net Other Purchases/ Disposals/ Transfer to June 30, AFS financial assets Equity securities 1,024,935 19,241 10,175 27,289 (31,692 ) — 1,049,948 Beneficiary certificates 530,511 3,442 (2,188 ) 127,147 (70,600 ) — 588,312 Sub-total 1,555,446 22,683 7,987 154,436 (102,292 ) — 1,638,260 Derivative assets 99 185 — — (284 ) — — Total 1,595,698 44,069 7,987 156,908 (119,996 ) — 1,684,666 Financial liabilities: Financial liabilities held for trading Derivative liabilities 33,524 14,142 — 501 (15,015 ) — 33,152 Financial liabilities designated at FVTPL Equity-linked securities 673,709 83,962 — — (235,296 ) — 522,375 Total 707,233 98,104 — 501 (250,311 ) — 555,527 (*1) The loss amounting to 61,518 million Won for the six months ended June 30, 2017, which is from financial assets and liabilities that the Group holds, has been recognized in net gain (loss) on financial instruments at FVTPL and net gain (loss) on AFS financial assets in the statement of comprehensive income. (*2) The Group recognizes transfers between levels at the end of reporting period within which events have occurred or conditions have changed. (4) Sensitivity analysis on the unobservable inputs used for measuring Level 3 financial instruments The sensitivity analysis of the financial instruments has been performed by classifying with favorable and unfavorable changes based on how changes in unobservable assumptions would have effects on the fluctuations of financial instruments’ value. When the fair value of a financial instrument is affected by more than one unobservable assumption, the below table reflects the most favorable or the most unfavorable changes which resulted from varying the assumptions individually. The sensitivity analysis was performed for two types of level 3 financial instruments: (1) interest rate related derivatives, currency related derivatives, equity related derivatives, equity-linked securities beneficiary certificates and loans of which fair value changes are recognized as net income; (2) equity securities of which fair value changes are recognized as other comprehensive income. The equity investments classified as Level 3 equity securities whose costs are considered to provide the best estimate of fair value are excluded from sensitivity analysis. The following table presents the sensitivity analysis to disclose the effect of reasonably possible volatility on the fair value of a Level 3 financial instruments (Unit: Korean Won in millions): June 30, 2018 Net income (loss) Other comprehensive income (loss) Favorable Unfavorable Favorable Unfavorable Financial assets: Financial assets at FVTPL Derivative assets (*1) (*2) 4,305 (2,452 ) — — Loans 422 (323 ) — — Debt securities 914 (784 ) — — Equity securities (*3) (*4) 10,740 (7,562 ) — — Beneficiary certificates (*4) 1,436 (1,544 ) — — Financial assets at FVTOCI Equity securities (*3) (*4) — — 19,464 (8,704 ) Total 17,817 (12,665 ) 19,464 (8,704 ) June 30, 2018 Net income (loss) Other comprehensive income (loss) Favorable Unfavorable Favorable Unfavorable Financial liabilities: Financial liabilities at fair value through profit or loss mandatorily measured at fair value Derivative liabilities (*1) (*2) 2,409 (4,285 ) — — Financial liabilities at fair value through profit or loss designated as upon initial recognition Equity-linked securities (*1) 1,083 (1,158 ) — — Total 3,492 (5,443 ) — — December 31, 2017 Net income (loss) Other comprehensive income (loss) Favorable Unfavorable Favorable Unfavorable Financial assets: Financial assets held for trading Derivatives assets (*1) (*2) 1,234 (526 ) — — Financial assets designed at FVTPL Debt securities (*5) 265 (309 ) — — Equity securities (*5) 670 (624 ) — — AFS Financial assets Equity securities (*3) (*4) — — 28,583 (15,246 ) Beneficiary certificates (*4) — — 1,861 (1,857 ) Total 2,169 (1,459 ) 30,444 (17,103 ) Financial liabilities: Financial liabilities held for trading Derivative liabilities (*1) (*2) 5 (513 ) — — Financial liabilities designated at FVTPL Equity-linked securities (*1) 8 (7 ) — — Total 13 (520 ) — — (*1) Fair value changes of equity related derivatives assets and liabilities and equity-linked securities are calculated by increasing or decreasing historical volatility of the stock price and correlation, which are major unobservable variables, by 10%, respectively. In the case of interest rate related derivative assets and liabilities, fair value changes are calculated by increasing or decreasing the volatility of interest rate, which are major unobservable variables, by 10%. (*2) Both derivative assets and liabilities for held for trading and hedging are included. (*3) Fair value changes of equity securities are calculated by increasing or decreasing growth rate (0~1%) and discount rate or liquidation value (-1~1%). (*4) Even if the sensitivity analysis of the capital contributions and beneficiary certificates is not possible in practice, fair value changes of beneficiary certificates and other securities whose major unobservable variables are composed of the real estate are calculated by increasing or decreasing price fluctuation of real estate which is underlying assets and discount rate by 1%. (*5) Changes of fair value are measured by increasing or decreasing the discount rate by 10%, which is major unobservable variable, respectively. (5) Fair value and carrying amount of financial assets and liabilities that are recorded at amortized cost are as follows (Unit: Korean Won in millions): June 30, 2018 Fair value Book Level 1 Level 2 Level 3 Total Financial assets: Securities at amortized cost 1,792,215 15,911,262 — 17,703,477 17,702,129 Loans and other financial assets at amortized cost — — 277,718,440 277,718,440 277,720,003 Financial liabilities: Deposits due to customers — 237,811,780 — 237,811,780 237,900,166 Borrowings — 15,924,417 — 15,924,417 15,899,599 Debentures — 26,586,897 — 26,586,897 26,752,725 Other financial liabilities — 21,405,921 — 21,405,921 21,408,267 December 31, 2017 Fair value Book Level 1 Level 2 Level 3 Total Financial assets: HTM financial assets 1,206,292 15,509,387 — 16,715,679 16,749,296 Loans and receivables — — 265,570,649 265,570,649 267,106,204 Financial liabilities: Deposits due to customers — 234,682,775 — 234,682,775 234,695,084 Borrowings — 14,754,506 — 14,754,506 14,784,706 Debentures — 27,889,781 — 27,889,781 27,869,651 Other financial liabilities — 13,890,789 — 13,890,789 13,892,461 The fair values of financial instruments are measured using quoted market price in active markets. In case there is no active market for financial instruments, the Group determines the fair value using valuation methods. Valuation methods and input variables for financial assets and liabilities that are measured at amortized costs are given as follows: Valuation methods Input variables Securities at amortized cost (HTM financial assets in previous year) The fair value is measured by discounting the projected cash flows of debt securities by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the issuers of the securities. Risk-free market rate Loans and other financial assets at amortized cost (Loans and receivables in previous year) The fair value is measured by discounting the projected cash flows of loan products by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the debtor. Risk-free market rate, credit spread and prepayment-rate Deposits due to customers, borrowings, debentures and other financial liabilities The fair value is measured by discounting the projected cash flows of debt products by applying the market discount rate that is reflecting credit rating of the Group. Risk-free market rate and forward rate (6) Financial instruments by category Carrying amounts of financial assets and liabilities are as follows (Unit: Korean Won in millions): June 30, 2018 Financial assets Financial asset Financial assets Financial assets at Derivatives Total Deposits 24,921 — 17,770,356 — 17,795,277 Securities at fair value through profit or loss 3,587,605 — — — 3,587,605 Securities at FVTOCI — 14,644,608 — — 14,644,608 Securities at amortized cost — — 17,702,129 — 17,702,129 Loans 336,967 — 248,794,014 — 249,130,981 Derivative assets 2,391,211 — — 12,395 2,403,606 Other financial assets at amortized cost — — 11,155,633 — 11,155,633 Total 6,340,704 14,644,608 295,422,132 12,395 316,419,839 Financial liabilities June 30, 2018 Financial liabilities Financial liabilities Derivatives Total Deposits due to customers 24,485 237,900,166 — 237,924,651 Borrowings 176,097 15,899,599 — 16,075,696 Debentures — 26,752,725 — 26,752,725 Derivative liabilities 2,377,750 — 67,505 2,445,255 Other financial liabilities (*) — 21,463,163 — 21,463,163 Total 2,578,332 302,015,653 67,505 304,661,490 (*) Other financial liabilities include 54,896 million Won of financial guarantee liabilities measured at amortized cost included in provisions (Note 23). December 31, 2017 Financial assets Financial assets AFS financial HTM financial Loans Derivatives Total Deposits 25,972 — — 8,868,378 — 8,894,350 Financial assets at FVTPL 2,701,330 — — — — 2,701,330 AFS financial assets — 15,352,950 — — — 15,352,950 HTM financial assets — — 16,749,296 — — 16,749,296 Loans — — — 251,523,301 — 251,523,301 Derivative assets 3,115,775 — — — 59,272 3,175,047 Other financial assets at amortized cost — — — 6,714,525 — 6,714,525 Total 5,843,077 15,352,950 16,749,296 267,106,204 59,272 305,110,799 Financial liabilities June 30, 2017 Financial liabilities Financial liabilities Derivatives Total Deposits due to customers 25,964 234,695,084 — 234,721,048 Borrowings 160,057 14,784,706 — 14,944,763 Debentures 91,739 27,869,651 — 27,961,390 Derivative liabilities 3,150,149 — 67,754 3,217,903 Other financial liabilities (*) — 13,964,158 — 13,964,158 Total 3,427,909 291,313,599 67,754 294,809,262 (*) Other financial liabilities include 71,697 million Won of financial guarantee liabilities measured at amortized cost included in provisions (Note 23).

Derecognition and offset of fin

Derecognition and offset of financial instruments	6 Months Ended
	Jun. 30, 2018
Disclosure of derecognition and offsetting of financial assets and liabilities [Abstract]
Disclosure of derecognition and offsetting of financial assets and liabilities	12. DERECOGNITION AND OFFSET OF FINANCIAL INSTRUMENTS (1) Derecognition of financial instruments Transferred financial assets that do not meet the condition of derecognition in their entirety. a) Disposal of securities under repurchase agreements The financial instruments that were disposed but the Group agreed to repurchase at the fixed amounts at the same time, so that they did not meet the conditions of derecognition, are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Assets transferred Financial assets at FVTOCI 10,002 — AFS financial assets — 9,998 Securities at amortized cost 5,444 — HTM financial assets — 5,436 Total 15,446 15,434 Related liabilities Bonds sold under repurchase agreements 5,372 3,173 b) Securities loaned When the Group loans its securities to outside parties, the legal ownerships of the securities are transferred; however, they should be returned at the end of lending period. Therefore, the Group does not derecognize them from the financial statements as it owns majority of risks and benefits from the securities continuously, regardless of the transfer of legal ownership. The carrying amounts of the securities loaned are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Loaned to Financial assets at FVTOCI Korean treasury, corporation bonds and others 50,139 — Korea Securities AFS financial assets Korean treasury, government bonds and others — 170,256 Korea Securities Total 50,139 170,256 The details of the transferred financial assets that are not meet the condition of derecognition in their entirety, such as disposal of securities under repurchase agreement or securities loaned, are explained in Note 18. (2) The offset of financial assets and liabilities The Group possesses both the uncollected domestic exchange receivables and the unpaid domestic exchange payable, which satisfy offsetting criteria of IAS 32. Therefore, the total number of uncollected domestic exchange receivables or unpaid domestic exchange payable has been countervailed with part of unpaid domestic exchange payable or uncollected domestic exchange receivables and has been disclosed in loans at amortized cost and other financial assets (loans and receivables in previous year) or other financial liabilities of the Group’s statements of financial position. The Group possesses the derivative assets, derivative liabilities, receivable spot exchange and payable spot exchange that do not satisfy the offsetting criteria of IAS 32, but provide the Group under the circumstances of the trading party’s defaults, insolvency or bankruptcy, the right of offsetting. Item such as cash collateral cannot satisfy the offsetting criteria of IAS 32, but in accordance with the collateral arrangements and under the circumstances of the trading party’s default, insolvency or bankruptcy, the net amount of derivative assets and derivative liabilities, receivable spot exchange and payable spot exchange can be offset. The Group has entered into a resale and repurchase agreement and accounted it as a collateralized borrowing. The Group has also entered into a resale and purchase agreement and accounted it as a secured advance. The resale and repurchase agreements can have the offsetting right only under the trading party’s default, insolvency or bankruptcy, which do not satisfy the offsetting criteria of IAS 32. The Group recorded the collateralized borrowing in borrowings and the secured loans in loans and receivables. The Group under the repurchase agreements has offsetting right only upon the counterparty’s default, insolvency or bankruptcy; thus, the repurchase agreements are applied by the TBMA/ISMA Global Master Repurchase Agreement, which does not satisfy the offsetting criteria of IAS 32. The Group disclosed bonds sold (purchased) under repurchase(resale) agreements as borrowings loan at amortized cost and other financial assets (loans and receivables in previous year). As of June 30, 2018 and December 31, 2017, the financial instruments to be off set and may be covered by master netting agreements and similar agreements are as follows (Unit: Korean Won in millions): June 30, 2018 Gross Gross Net Related amounts not set off Net Netting Cash Financial assets: Derivative assets and others (*1) 2,132,698 — 2,132,698 8,716,272 21,543 857,980 Receivable spot exchange (*2) 7,463,097 — 7,463,097 Bonds purchased under resale agreements (*2) 6,999,881 — 6,999,881 6,999,881 — — Domestic exchanges receivable (*2)(*5) 27,527,610 27,338,204 189,406 — — 189,406 Total 44,123,286 27,338,204 16,785,082 15,716,153 21,543 1,047,386 June 30, 2018 Gross Gross Net Related amounts not set off Net Netting Cash Financial liabilities: Derivative liabilities and others (*1) 2,305,516 — 2,305,516 8,704,614 208,955 856,626 Payable spot exchange (*3) 7,464,679 — 7,464,679 Bonds sold under repurchase agreements (*4) 5,372 — 5,372 5,372 — — Domestic exchanges payable (*3)(*5) 31,538,065 27,338,204 4,199,861 3,408,953 — 790,908 Total 41,313,632 27,338,204 13,975,428 12,118,939 208,955 1,647,534 (*1) The items include derivatives held for trading, derivatives held for hedging and equity-linked securities. (*2) The items are included in loan at amortized cost and other financial assets. (*3) The items are included in other financial liabilities. (*4) The items are included in borrowings. (*5) Certain financial assets and liabilities are presented as net amounts. December 31, 2017 Gross Gross Net Related amounts not set off in Net Netting Cash Financial assets: Derivative assets and others (*1) 2,992,476 1,710 2,990,766 5,787,448 174,415 796,629 Receivable spot exchange (*2) 3,767,726 — 3,767,726 Bonds purchased under resale agreements (*2) 16,859,064 — 16,859,064 16,859,064 — — Domestic exchanges receivable (*2)(*5) 39,050,227 38,985,354 64,873 — — 64,873 Total 62,669,493 38,987,064 23,682,429 22,646,512 174,415 861,502 December 31, 2017 Gross Gross Net Related amounts not set off in Net Netting Cash Financial liabilities: Derivative liabilities and others (*1) 3,160,217 1,710 3,158,507 5,866,682 157,750 857,961 Payable spot exchange (*3) 3,723,886 — 3,723,886 Bonds sold under repurchase agreements (*4) 3,173 — 3,173 3,173 — — Domestic exchanges payable (*3)(*5) 40,284,515 38,985,354 1,299,161 1,293,931 — 5,230 Total 47,171,791 38,987,064 8,184,727 7,163,786 157,750 863,191 (*1) The items include derivatives held for trading, derivatives for hedging and equity linked securities. (*2) The items are included in loans and receivables. (*3) The items are included in other financial liabilities. (*4) The items are included in borrowings. (*5) Certain financial assets and liabilities are presented at as net amounts.

Investment in Joint Ventures an

Investment in Joint Ventures and Associates	6 Months Ended
	Jun. 30, 2018
Equity Method Investments And Joint Ventures [Abstract]
Investment In Joint Ventures And Associates	13. INVESTMENTS IN JOINT VENTURES AND ASSOCIATES (1) Investments in joint ventures and associates accounted for using the equity method of accounting are as follows (Unit: Korean Won in millions): Percentage of Financial Joint ventures and Associates Main business June 30, December 31, Woori Bank: Kumho Tire Co., Inc. (*1)(*2) Manufacturing 14.2 14.2 March 31 (*3) Woori Service Networks Co., Ltd. (*4) Freight & staffing services 4.9 4.9 May 31 (*3) Korea Credit Bureau Co., Ltd. (*5) Credit information 9.9 9.9 June 30 Korea Finance Security Co., Ltd. (*4) Security service 15.0 15.0 May 31 (*3) Chin Hung International Inc. (*2) Construction 25.3 25.3 May 31 (*3) Poonglim Industrial Co., Ltd. (*6)(*9) Construction — 29.4 — STX Engine Co., Ltd. (*10) Manufacturing — 29.2 — STX Corporation (*1)(*11) Wholesale of non-specialized 19.7 19.7 May 31 (*3) Saman Corporation (*5) General construction Technology service 9.2 9.2 May 31 (*3) Dongwoo C & C Co., Ltd. (*6) Construction 23.2 23.2 — SJCO Co., Ltd. (*6) Aggregate transportation and wholesale 26.5 26.5 — G2 Collection Co., Ltd. (*6) Wholesale and retail sales 28.9 28.9 — The Base Enterprise Co., Ltd. (*6) Manufacturing 48.4 48.4 — Kyesan Engineering Co., Ltd. (*6) Construction 23.2 23.2 — Good Software Lap Co., Ltd. (*6) Service 28.9 28.9 — Wongwang Co., Ltd. (*6) Wholesale and real estate 29.0 29.0 — Sejin Construction Co., Ltd. (*6) Construction 29.6 29.6 — QTS Shipping Co., Ltd. (*6) Composite transportation Arrangement 49.4 49.4 — DAEA SNC Co., Ltd. (*6) Wholesale and retail sales 24.0 24.0 ARES-TECH Co., Ltd. (*6) Electronic component manufacturing 23.4 23.4 — Reading Doctors Co., Ltd. (*6) Other service business 35.4 35.4 — PREXCO Co., Ltd. (*6) Manufacturing 28.1 28.1 — Hyunwoo International Co., Ltd. (*6) Manufacturing 25.9 25.9 — Jiwon Plating Co., Ltd. (*6) Plating 20.5 20.5 — Cultizm Korea LTD Co., Ltd. (*6) Wholesale and retail sales 31.3 31.3 — Gil Co.,Ltd. (*6) Manufacturing 26.1 26.1 — NK Eng Co., Ltd. (*6) Manufacturing 23.1 23.1 — Youngdong Sea Food Co., Ltd. (*6)(*7) Processed sea food manufacturing 24.0 — — Woori Growth Partnerships New Technology Private Equity Fund Other financial business 23.1 23.1 June 30 2016KIF-IMM Other financial business 20.0 20.0 June 30 K BANK Co., Ltd. (*5) Finance 13.0 13.0 May 31 (*3) Smart Private Equity Fund No.2 Other financial business 20.0 20.0 June 30 Woori Bank-Company K Korea Movie Asset Fund Other financial business 25.0 25.0 June 30 Well to Sea No. 3 Private Equity Fund (*12) Finance 50.0 50.0 March 31 (*3) Partner One Value Up I Private Equity Fund (*8) Other financial business 23.3 — June 30 IBK KIP Seongjang Dideemdol 1st Private Investment Limited Partnership (*8) Other Finance business 20.0 — June 30 Woori Investment Bank Co., Ltd.: Nomura-Rifa Private Real Estate Investment Trust No.17 Other financial business 21.9 25.0 June 30 (*1) The Group has significant influence on these entities through its position in the creditors’ council which is the decision making body regarding to financial and operational policies of associates. (*2) The investments in associates that have quoted market prices are Kumho Tire Co., Ltd. (current period: KRW 6,310, previous year: KRW 4,425), Chin Hung International Inc. (current period: KRW 1,935, previous year: KRW 1,915). (*3) The significant transactions and events between the end of reporting period of the associates and the Group have been properly incorporated. (*4) Most of the significant business transactions of associates are with the Group as of June 30, 2018 and December 31, 2017. (*5) The Group can participate in decision-making body and exercise significant influence over associates through business partnerships. (*6) The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017. (*7) As of December 31, 2017, the ownership ratio of the common stocks was more than 20%, but the entity was excluded from investments in associates because it has been under rehabilitation and not able to exercise significant influence. However, as of June 30, 2018, it was included in investments in associates by finalizing rehabilitation process by the court administration. (*8) Due to capital contribution by the Group for the six months ended June 30, 2018, the entities has been included in the investment in associates. (*9) The Group does not have significant influence over the entity since it is going through work-out (*10) The entity was sold after it was transferred to assets held for sale for the year ended June 30, 2018. (*11) The shares of STX Corporation owned by the Group were reclassified as assets held for sale, as the creditor financial institutions committee entered into a contract with AFC Korea Co., Ltd. during the previous year to sell STX Corporation shares. (*12) The Bank has entered into a contract whereas the Bank (or a third party designated by the Bank) obtains a preemptive right to acquire the base assets (Aju Capital Co. Ltd.) of Well to Sea No. 3 Private Equity Fund, an affiliate of the Bank, when the Fund disposes them. (2) Changes in the carrying value of investments in joint ventures and associates accounted for using the equity method of accounting are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Acquisition January 1, Share of Acquisition Disposal Dividends Change in June 30, Kumho Tire Co., Inc. 175,652 98,933 (10,451 ) — — — (5,196 ) 83,286 Woori Service Networks Co., Ltd. 108 158 (20 ) — — — — 138 Korea Credit Bureau Co., Ltd. 3,313 5,816 692 — — (113 ) — 6,395 Korea Finance Security Co., Ltd. 3,267 3,519 4 — — (54 ) 1 3,470 Chin Hung International Inc. 130,779 45,101 3,179 — — — (484 ) 47,796 Poonglim Industrial Co., Ltd. 13,916 — — — — — — — STX Corporation 50,760 6,947 (816 ) — (5,865 ) — (266 ) — Saman Corporation 8,521 1,254 (48 ) — — — 34 1,240 Woori Growth Partnerships New Technology Private Equity Fund 28,833 27,611 1,139 — (3,346 ) (484 ) — 24,920 2016KIF-IMM 6,840 6,840 — 6,780 — — — 13,620 K BANK Co., Ltd. 45,392 31,735 (5,384 ) — — — 7 26,358 Smart Private Equity Fund No.2 3,000 2,932 (21 ) — — — — 2,911 Woori Bank-Company K Korea Movie Asset Fund 3,000 2,957 10 — — — — 2,967 Well to Sea No.3 Private Equity Fund 101,992 182,309 10,321 — (508 ) — (6,423 ) 185,699 Partner One Value Up I Private Equity Fund 10,000 — (13 ) 10,000 — — — 9,987 IBK KIP Seongjang Dideemdol 1st Private Investment Limited Partnership 3,268 — — 3,268 — — — 3,268 Nomura-Rifa Private Real Estate Investment Trust No.17 1,000 939 (54 ) — — — — 885 Total 589,641 417,051 (1,462 ) 20,048 (9,719 ) (651 ) (12,327 ) 412,940 (*1) Investments in joint ventures and associates decreased by 5,865 million Won through transfers to assets held for sale which occurred during the six months ended June 30, 2018. For the six months ended June 30, 2017 Acquisition January 1, Share of Acquisition Disposal Dividends Change in Others June 30, Woori Blackstone Korea Opportunity No.1 Private Equity Fund 6,881 15,289 (1,460 ) — — — — — 13,829 Kumho Tire Co., Inc. 175,652 200,332 2 — — — (1,623 ) — 198,711 Woori Service Networks Co., Ltd. 108 145 (10 ) — — (8 ) — — 127 Korea Credit Bureau Co., Ltd. 3,313 5,592 508 — — (149 ) — — 5,951 Korea Finance Security Co., Ltd. 3,266 3,376 63 — — (54 ) — — 3,385 Chin Hung International Inc. 89,725 43,032 (20,050 ) 41,053 — — 171 (25,966 ) 38,240 Poonglim Industrial Co., Ltd. 13,916 — — — — — — — — STX Engine Co., Ltd. 92,038 43,036 722 — — — 4,047 — 47,805 SamHo Co., Ltd. 7,492 19,729 2,021 — (16,354 ) — (73 ) (5,323 ) — STX Corporation 42,215 — (33,739 ) 8,546 — — (215 ) 27,772 2,364 Saman Corporation 8,521 8,699 (96 ) — — — 26 — 8,629 Woori Growth Partnerships New Technology Private Equity Fund 13,602 13,118 (371 ) 5,745 (498 ) — (156 ) — 17,838 2016KIF-IMM 1,800 1,800 — 3,240 — — — — 5,040 K BANK Co., Ltd. 32,500 30,442 (5,861 ) — — — (139 ) — 24,442 Smart Private Equity Fund No.2 3,000 — (47 ) 3,000 — — — — 2,953 Woori Bank-Company K Korea Movie Asset Fund 1,500 — (15 ) 1,500 — — — — 1,485 Woori Renaissance Holdings 63,000 54,422 (622 ) — — (57,109 ) — 3,309 — 558,529 439,012 (58,955 ) 63,084 (16,852 ) (57,320 ) 2,038 (208 ) 370,799 (*1) Changes in investments in joint ventures and associates due to debt-equity swap is 51,405 million Won. (*2) Investments in joint ventures and associates decreased by 16,354 million Won through transfers to assets held for sale occurred for the six months ended June 30, 2017. (3) Summary financial information relating to investments in joint ventures and associates accounted for using the equity method of accounting is as follows (Unit: Korean Won in millions): June 30, 2018 Assets Liabilities Operating Net income Kumho Tire Co., Inc. 4,513,972 3,521,608 624,981 (10,774 ) Woori Service Networks Co., Ltd. 4,909 2,111 7,250 456 Korea Credit Bureau Co., Ltd. 80,792 18,764 37,342 5,919 Korea Finance Security Co., Ltd. 32,635 9,501 27,161 91 Chin Hung International Inc. 403,962 311,502 263,861 19,062 Saman Corporation 89,932 61,583 26,418 (326 ) Woori Growth Partnerships New Technology Private Equity Fund 108,427 441 7,865 4,936 2016KIF-IMM 65,760 383 6 (754 ) K BANK Co., Ltd. 1,758,930 1,557,206 24,296 (32,126 ) Smart Private Equity Fund No.2 14,605 51 1 (106 ) Woori Bank-Company K Korea Movie Asset Fund 11,872 3 893 769 Well to Sea No.3 Private Equity Fund 5,297,764 4,759,158 140,041 13,450 Partner One Value Up I Private Equity Fund 43,114 172 114 (58 ) IBK KIP Seongjang Dideemdol 1st Private Investment Limited Partnership 15,843 744 4 (822 ) Nomura-Rifa Private Real Estate Investment Trust No.17 20,433 16,407 56 (55 ) December 31, 2017 Assets Liabilities Operating Net income Kumho Tire Co., Inc. 5,105,107 3,928,327 2,136,569 (61,748 ) Woori Service Networks Co., Ltd. 4,982 1,780 14,887 1,003 Korea Credit Bureau Co., Ltd. 75,504 19,323 68,750 3,580 Korea Finance Security Co., Ltd. 33,915 10,461 55,610 1,071 Chin Hung International Inc. 341,284 259,454 513,285 28,698 Poonglim Industrial Co., Ltd. 241,063 309,925 107,360 (29,812 ) STX Corporation 595,348 543,458 1,371,272 342,869 Saman Corporation 98,435 69,929 76,135 (6,096 ) Woori Growth Partnerships New Technology Private Equity Fund 120,133 485 1,024 (3,199 ) 2016KIF-IMM 32,815 380 6 (1,515 ) K BANK Co., Ltd. 1,244,270 1,001,121 19,231 (74,403 ) Smart Private Equity Fund No.2 14,711 51 1 (340 ) Woori Bank-Company K Korea Movie Asset Fund 11,830 2 16 (172 ) Well to Sea No.3 Private Equity Fund 5,068,424 4,534,957 131,488 162,743 Nomura-Rifa Private Real Estate Investment Trust No.17 20,265 16,507 62 (242 ) (4) The entities that the Group has not applied equity method of accounting although the Group’s ownership interest is more than 20% as of June 30, 2018 and December 31, 2017 are as follows: June 30, 2018 Associate (*) Number of shares owned Ownership (%) Poonglim Industrial Co., Ltd. 4,142,782 29.1 Orient Shipyard Co., Ltd. 464,812 21.4 Saenuel Co., Ltd. 3,531 37.4 E Mirae Tech Co., Ltd. 7,696 41.0 Jehin Trading Co., Ltd. 81,610 27.3 The season Co., Ltd. 18,187 30.1 Yuil PESC Co., Ltd. 8,642 24.0 Sinseong Trading Co., Ltd. 2,584 27.2 CL Tech Co., Ltd. 13,759 38.6 Force TEC Co., Ltd. 4,780,907 25.8 Protronics Co., Ltd. 95,921 48.1 Instern Co., Ltd. 14,296 20.1 (*) Even though the Group’s ownership interest of the entity is more than 20%, the Group does not have significant influence over the entity since it is going through work-out As of December 31, 2017 Associate (*) Number of shares owned Ownership (%) Orient Shipyard Co., Ltd. 465,050 21.4 Saenuel Co., Ltd. 3,531 37.4 E Mirae Tech Co., Ltd. 7,696 41.0 Jehin Trading Co., Ltd. 81,610 27.3 The season Co., Ltd. 18,187 30.1 Yuil PESC Co., Ltd. 8,642 24.0 Youngdong Sea Food Co., Ltd. 12,106 24.0 Sinseong Trading Co., Ltd. 2,584 27.2 CL Tech Co., Ltd. 13,759 38.6 Force TEC Co., Ltd. 4,780,907 25.8 Protronics Co., Ltd. 95,921 48.1 Instern Co., Ltd. 14,296 20.1 (*) Even though the Group’s ownership interest of the entity is more than 20%, the Group does not have significant influence over the entity since it is going through work-out (5) As of June 30, 2018 and December 31, 2017, the reconciliations from the net assets of associates based on the ownership ratio of the Group to its corresponding book value of investment in joint ventures and associates are as follows (Unit: Korean Won in millions except for ownership): June 30, 2018 Total net Ownership Ownership Cost-book Impairment Intercompany Book Kumho Tire Co., Inc. (*) 954,857 14.2 135,122 48,459 (102,843 ) 2,548 83,286 Woori Service Networks Co., Ltd. 2,798 4.9 138 — — — 138 Korea Credit Bureau Co., Ltd. 62,028 9.9 6,149 246 — — 6,395 Korea Finance Security Co., Ltd. 23,134 15.0 3,470 — — — 3,470 Chin Hung International Inc. (*) 92,316 25.3 23,361 24,565 — (130 ) 47,796 Saman Corporation 28,349 9.2 2,605 5,373 (6,738 ) — 1,240 Woori Growth Partnerships New Technology Private Equity Fund 107,986 23.1 24,920 — — — 24,920 2016KIF-IMM 65,377 20.0 13,075 — — 545 13,620 K BANK Co., Ltd. 201,724 13.0 26,162 — — 196 26,358 Smart Private Equity Fund No.2 14,554 20.0 2,911 — — — 2,911 Woori Bank-Company K Korea Movie Asset Fund 11,869 25.0 2,967 — — — 2,967 Well to Sea No.3 Private Equity Fund (*) 371,813 50.0 185,816 — — (117 ) 185,699 Partner One Value Up I Private Equity Fund 42,942 23.3 9,987 — — — 9,987 IBK KIP Seongjang Dideemdol 1st Private Investment Limited Partnership 15,099 20.0 3,020 — — 248 3,268 Nomura-Rifa Private Real Estate Investment Trust No.17 4,026 21.9 882 — — 3 885 (*) The net asset amount is after reflecting debt-equity swap and others. December 31, 2017 Total net Ownership Ownership Cost-book Impairment Intercompany Book Kumho Tire Co., Inc. (*) 1,065,421 14.2 150,767 48,459 (102,843 ) 2,550 98,933 Woori Service Networks Co., Ltd. 3,202 4.9 158 — — — 158 Korea Credit Bureau Co., Ltd. 56,181 9.9 5,568 248 — — 5,816 Korea Finance Security Co., Ltd. 23,454 15.0 3,519 — — — 3,519 Chin Hung International Inc. (*) 81,686 25.3 20,671 24,565 — (135 ) 45,101 Poonglim Industrial Co., Ltd. (*) (168,154 ) 29.4 (49,446 ) 54,542 (20,504 ) 15,408 — STX Corporation 51,890 19.7 10,232 24,614 (27,904 ) 5 6,947 Saman Corporation 28,506 9.2 2,619 5,373 (6,738 ) — 1,254 Woori Growth Partnerships New Technology Private Equity Fund 119,648 23.1 27,611 — — — 27,611 2016KIF-IMM 32,435 20.0 6,487 — — 353 6,840 K BANK Co., Ltd. 243,149 13.0 31,535 — — 200 31,735 Smart Private Equity Fund No.2 14,660 20.0 2,932 — — — 2,932 Woori Bank-Company K Korea Movie Asset Fund 11,828 25.0 2,957 — — — 2,957 Well to Sea No.3 Private Equity Fund (*) 364,909 50.0 182,366 — — (57 ) 182,309 Nomura-Rifa Private Real Estate Investment Trust No.17 3,758 25.0 939 — — — 939 (*) The net asset amount is after reflecting debt-equity swap and others.

Investment Properties

Investment Properties	6 Months Ended
	Jun. 30, 2018
Disclosure Of Investment Property [Abstract]
Investment Properties	14. INVESTMENT PROPERTIES (1) Details of investment properties are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Acquisition cost 417,692 404,741 Accumulated depreciation (36,515 ) (33,440 ) Net carrying value 381,177 371,301 (2) Changes in investment properties are as follows (Unit: Korean Won in millions): For the six months ended June 30 2018 2017 Beginning balance 371,301 358,497 Acquisition 7,311 1,221 Disposal (1,738 ) (225 ) Depreciation (2,010 ) (1,991 ) Transfers 6,333 (2,708 ) Classified to held for sale — (534 ) Foreign currencies translation adjustments (79 ) (120 ) Others 59 5,797 Ending balance 381,177 359,937 (3) Rental fee earned from investment properties is amounting to 2,396 million Won and 2,411 million Won for the six months ended June 30, 2018 and 2017, respectively.

Premises and Equipment

Premises and Equipment	6 Months Ended
	Jun. 30, 2018
Disclosure Of Property Plant And Equipment [Abstract]
Premises And Equipment	15. PREMISES AND EQUIPMENT (1) Details of premises and equipment are as follows (Unit: Korean Won in millions): June 30, 2018 Land Building Properties for Structures in Construction Structures Total Acquisition cost 1,482,169 863,503 1,105,029 441,835 4,421 20 3,896,977 Accumulated depreciation — (197,688 ) (868,768 ) (379,750 ) — (17 ) (1,446,223 ) Net carrying value 1,482,169 665,815 236,261 62,085 4,421 3 2,450,754 December 31, 2017 Land Building Properties for Structures in Construction Structures Total Acquisition cost 1,487,278 867,804 1,024,186 429,665 64,559 20 3,873,512 Accumulated depreciation — (186,958 ) (844,114 ) (364,878 ) — (17 ) (1,395,967 ) Net carrying value 1,487,278 680,846 180,072 64,787 64,559 3 2,477,545 (2) Details of changes in premises and equipment are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Land Building Properties for Structures in Construction Structures Total Beginning balance 1,487,278 680,846 180,072 64,787 64,559 3 2,477,545 Acquisitions 463 4,326 27,635 6,928 3,342 — 42,694 Disposals — — (72 ) (89 ) — — (161 ) Depreciation — (12,960 ) (36,144 ) (17,696 ) — — (66,800 ) Classified to held for sale (3,573 ) (2,477 ) — — — — (6,050 ) Transfer (1,910 ) (4,423 ) 63,433 — (63,433 ) — (6,333 ) Foreign currencies translation adjustments (89 ) (121 ) 352 489 (47 ) — 584 Acquisition through business combination — — 969 661 — — 1,630 Others — 624 16 7,005 — — 7,645 Ending balance 1,482,169 665,815 236,261 62,085 4,421 3 2,450,754 For the six months ended June 30, 2017 Land Building Properties for Structures in Construction Structures Total Beginning balance 1,488,745 691,699 189,902 68,958 18,717 4 2,458,025 Acquisitions — 3,831 31,624 8,120 25,053 — 68,628 Disposals (606 ) (205 ) (235 ) (423 ) — — (1,469 ) Depreciation — (13,029 ) (38,063 ) (18,253 ) — (1 ) (69,346 ) Classified to assets held for sale (1,743 ) (441 ) — — — — (2,184 ) Transfer 2,466 403 5,485 — (5,646 ) — 2,708 Foreign currencies translation adjustments (596 ) (560 ) (676 ) (675 ) (247 ) — (2,754 ) Others — (6 ) 188 5,386 — — 5,568 Ending balance 1,488,266 681,692 188,225 63,113 37,877 3 2,459,176

Intangible assets

Intangible assets	6 Months Ended
	Jun. 30, 2018
Disclosure Of Intangible Assets [Abstract]
Intangible assets	16. INTANGIBLE ASSETS (1) Details of intangible assets are as follows (Unit: Korean Won in millions): June 30, 2018 Goodwill Software Industrial Development Others Membership Construction Total Acquisition cost 154,644 208,383 1,180 463,361 717,332 26,087 8,978 1,579,965 Accumulated amortization — (170,700 ) (611 ) (199,179 ) (550,996 ) — — (921,486 ) Accumulated impairment losses — — — — (137 ) (4,828 ) — (4,965 ) Net carrying value 154,644 37,683 569 264,182 166,199 21,259 8,978 653,514 December 31, 2017 Goodwill Software Industrial Development Others Membership Construction Total Acquisition cost 108,707 203,418 1,063 260,087 634,150 27,337 153,209 1,387,971 Accumulated amortization — (162,746 ) (524 ) (182,846 ) (516,467 ) — — (862,583 ) Accumulated impairment losses — — — — (137 ) (6,652 ) — (6,789 ) Net carrying value 108,707 40,672 539 77,241 117,546 20,685 153,209 518,599 (2) Details of changes in intangible assets are as follows (Unit: Korean Won in millions): June 30, 2018 Goodwill Software Industrial Development Others Membership Construction Total Beginning balance 108,707 40,672 539 77,241 117,546 20,685 153,209 518,599 Acquisitions — 3,737 117 21,455 36,191 2,311 84,318 148,129 Disposal — — — — — (2,107 ) — (2,107 ) Amortization (*) — (7,510 ) (87 ) (16,317 ) (34,162 ) — — (58,076 ) Reversal of impairment loss — — — — — 339 — 339 Transfer — — — 181,803 46,746 — (228,549 ) — Acquisition through business combination 47,406 763 — — — — — 48,169 Foreign currencies translation adjustment (1,469 ) 21 — — 243 74 — (1,131 ) Others — — — — (365 ) (43 ) — (408 ) Ending balance 154,644 37,683 569 264,182 166,199 21,259 8,978 653,514 (*) Amortization of other intangible assets amounting to 25,179 million Won is included in other operating expenses. June 30, 2017 Goodwill Software Industrial Development Others Membership Construction Total Beginning balance 124,803 35,477 313 70,697 164,364 20,086 67,999 483,739 Acquisitions 105 10,152 54 12,628 10,276 480 55,984 89,679 Disposal — — — — — (866 ) — (866 ) Amortization (*) — (8,064 ) (56 ) (11,515 ) (30,389 ) — — (50,024 ) Impairment loss — — — — — (128 ) — (128 ) Transfer — 8,091 — — 36 — (8,127 ) — Foreign currencies translation adjustment (7,479 ) (68 ) — — (1,053 ) (81 ) (383 ) (9,064 ) Others — (22 ) — (55 ) (6,371 ) (6 ) — (6,454 ) Ending balance 117,429 45,566 311 71,755 136,863 19,485 115,473 506,882 (*) Amortization of other intangible assets amounting to 24,443 million Won is included in other operating expenses.

Assets Held for sale

Assets Held for sale	6 Months Ended
	Jun. 30, 2018
Non-current assets or disposal groups classified as held for sale or as held for distribution to owners [Abstract]
Assets Held for Sale	17. ASSETS HELD FOR SALE Assets held for sale are as follows (Unit: Korean Won in millions): June 30, December 31, Investments in joint ventures and associates 5,865 46,217 Premises and equipment, etc (*) 12,840 2,407 Total 18,705 48,624 (*) As of June 30, 2018 and December 31, 2017, non-operating

Assets Subject to Lien and Asse

Assets Subject to Lien and Assets Acquired Through Foreclosures	6 Months Ended
	Jun. 30, 2018
Disclosure Of Collateral [Abstract]
Assets Subject To Lien And Assets Acquired Through Foreclosures	18. ASSETS SUBJECT TO LIEN AND ASSETS ACQUIRED THROUGH FORECLOSURES (1) Assets subjected to lien are as follows (Unit: Korean Won in millions): June 30, 2018 Collateral given to Amount Reason for collateral Loan at amortized cost and other financial assets Due from banks on time in local currency DaishinAMC and others 1,500 Right of pledge Due from banks in local currencies Samsung Securities Co., Ltd. and others 19,698 Margin deposit for futures or option Due from banks in foreign currencies Korea Investment & Securities Co., Ltd. and others 135,515 Foreign margin deposit for future or option and others Financial assets at FVTPL Korean financial institutions’ debt securities and others Kyobo Life Insurance Co., Ltd. and others 72,915 CSA collateral and others Financial assets at FVTOCI Korean treasury and corporate bonds Korea Securities Depository 10,002 Related to bonds sold under repurchase agreements (*) Korean treasury and government bonds and others The BOK and others 1,621,221 Settlement risk and others Securities at amortized cost Korean treasury and government bonds Korea Securities Depository 5,444 Related to bonds sold under repurchase agreements (*) Korean treasury and government bonds and others The BOK and others 4,908,149 Settlement risk and others Premises and equipment Land and building Credit Counselling & Recovery Service and others 6,065 Right to collateral and others Total 6,780,509 (*) The Group has the agreements to repurchase the sold assets at the predetermined price or the price that includes the rate of return and to provide the guarantee on the assets. The transferee has the right to sell or to provide as guarantee. Therefore, the Group does not derecognize the assets, but recognizes the relevant amounts as liability (bonds sold under repurchase agreements). December 31, 2017 Collateral given to Amount Reason for collateral Loan and receivables Due from banks on time in local currency Bank of China and others 6,629 Collaterals for issuing letter of guarantee and others Due from banks in local currencies Samsung Securities Co., Ltd. and others 10,809 Margin deposit for futures or option Due from banks in foreign currencies Korea Investment & Securities Co., Ltd. and others 9,136 Foreign margin deposit for future or option and others Financial assets at FVTPL Korean financial institutions’ debt securities and others Yuanta Securities Co., Ltd. and others 501,523 Substitute securities and others AFS financial assets Korean treasury and corporate bonds Korea Securities Depository and others 9,998 Related to bonds sold under repurchase agreements (*) Korean treasury and government bonds and others The BOK and others 1,570,608 Settlement risk and others HTM financial assets Korean treasury and government bonds Korea Securities Depository 5,436 Related to bonds sold under repurchase agreements (*) Korean financial institutions’ debt securities and others The BOK and others 7,605,292 Settlement risk and others Premises and equipment Land and building Credit Counselling & Recovery Service and others 6,186 Leasehold rights and others Total 9,725,617 (*) The Group has the agreements to repurchase the sold assets at the predetermined price or the price that includes the rate of return and to provide the guarantee on the assets. The transferee has the right to sell or to provide as guarantee. Therefore, the Group does not derecognize the assets, but recognizes the relevant amounts as liability (bonds sold under repurchase agreements). (2) The carrying amounts of assets acquired through foreclosure are as follows. (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Land 327 332 Buildings — 44 Total 327 376 (3) Securities loaned are as follows (Unit: Korean Won in millions): June 30, December 31, Loaned to Financial assets at FVTOCI Korean treasury, corporate bonds and others 50,139 — Korea Securities Finance Corporation AFS financial assets Korean treasury, government bonds and others — 170,256 Korea Securities Finance Corporation and others Total 50,139 170,256 Securities loaned are lending of specific securities to borrowers who agree to return the same quantity of the same security at the end of lending period. As the Group does not derecognize these securities, there are no liabilities recognized through such transactions relates to securities loaned. (4) Collaterals held that can be disposed and re-subjected Fair values of collaterals held that can be disposed and re-subjected June 30, 2018 Fair values of collaterals Fair values of collaterals were disposed or re-subjected to lien Securities 7,303,137 — December 31, 2017 Fair values of collaterals Fair values of collaterals were disposed or re-subjected to lien Securities 17,671,490 —

Other Assets

Other Assets	6 Months Ended
	Jun. 30, 2018
Miscellaneous assets [Abstract]
Other Assets	19. OTHER ASSETS Details of other assets are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Prepaid expenses 165,150 130,245 Advance payments 24,879 18,363 Non-operative 327 376 Others 12,444 9,420 Total 202,800 158,404

Financial Liabilitiy at Fair Va

Financial Liabilitiy at Fair Value Through Profit or Loss	6 Months Ended
	Jun. 30, 2018
Financial liabilities at fair value through profit or loss [Abstract]
Disclosure of financial liabilities at fair value through profit or loss	20. FINANCIAL LIABILITIES AT FVTPL (1) Financial liabilities at FVTPL are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Financial liabilities at fair value through profit or loss mandatorily measured at fair value 2,402,235 — Financial liabilities held for trading — 3,176,113 Financial liabilities at fair value through profit or loss designated as upon initial recognition 176,097 — Financial liabilities designated as at FVTPL — 251,796 Total 2,578,332 3,427,909 (2) Financial liabilities at fair value through profit or loss mandatorily measured at fair value(Financial liabilities held for trading) are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Deposits Gold banking liabilities 24,485 25,964 Derivative liabilities 2,377,750 3,150,149 Total 2,402,235 3,176,113 (3) Financial liabilities at fair value through profit or loss designated as upon initial recognition(Financial liabilities designated as at FVTPL) are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Equity linked securities index: Equity linked securities index in short position 176,097 160,057 Debentures: Debentures in local currency — 91,739 Total 176,097 251,796 Financial liabilities at fair value through profit or loss designated are designated as such in order to eliminate or significantly reduce accounting mismatch arising from recognition or measurement. (4) Credit risk adjustments to financial liabilities at fair value through profit or loss designated as upon initial recognition(Financial liabilities designated as at FVTPL) are as follows (Unit: Korean Won in millions): For the six months For the six months Financial liabilities at fair value through profit or loss designated as upon initial recognition 176,097 — Financial liabilities designated as at FVTPL — 616,177 Changes in fair value for credit risk adjustments (179 ) (261 ) Accumulated changes in credit risk adjustments (39 ) 89 The adjustment to reflect Group’s credit risk is considered in measuring the fair value of derivatives. The Group’s credit risk is determined by adjusting credit spread observed in credit rating of bank. (5) The difference between financial liabilities at fair value through profit or loss designated as upon initial recognition’s(Financial liabilities designated as at FVTPL) carrying amount and nominal amount at maturity is as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Carrying amount 176,097 251,796 Nominal amount at maturity 212,259 255,408 Difference (36,162 ) (3,612 ) (6) Changes in equity in relation to Financial liabilities at fair value through profit or loss designated as upon initial recognition 1) Realized cumulative gain or loss designated in other comprehensive income due to derecognition of financial liabilities designated at FVTPL is nil for the six months ended June 30, 2018. 2) Cumulative gains on financial liabilities designated at FVTPL replaced to retained earnings from other comprehensive income are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Equity-linked securities index: (8 )

Deposits Due to Customers

Deposits Due to Customers	6 Months Ended
	Jun. 30, 2018
Deposits from customers [Abstract]
Deposits Due To Customers	21. DEPOSITS DUE TO CUSTOMERS Details of deposits due to customers by type are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Deposits in local currency: Deposits on demand 9,337,563 9,349,070 Deposits at termination 198,768,356 194,292,679 Mutual installment 32,292 34,055 Deposits on notes payables 1,705,871 1,323,679 Deposits on CMA 154,782 164,431 Certificate of deposits 4,592,575 4,436,443 Other deposits 1,401,853 1,451,841 Subtotal 215,993,292 211,052,198 Deposits in foreign currency: Deposits in foreign currencies 21,950,041 23,682,896 Present value discount (43,167 ) (40,010 ) Total 237,900,166 234,695,084

Borrowings and Debentures

Borrowings and Debentures	6 Months Ended
	Jun. 30, 2018
Borrowings [Abstract]
Borrowings And Debentures	22. BORROWINGS AND DEBENTURES (1) Details of borrowings are as follows (Unit: Korean Won in millions): June 30, 2018 Lenders Interest rate (%) Amount Borrowings in local currency: Borrowings from The BOK The BOK 0.5 ~ 0.8 1,420,990 Borrowings from government funds Small Enterprise And Market Service and others 0.0 ~ 2.5 1,782,603 Others The Korea Development Bank and others 0.0 ~ 4.0 4,665,845 Subtotal 7,869,438 Borrowings in foreign currencies: Borrowings in foreign currencies The Export-Import 0.0 ~ 6.5 7,148,402 Offshore borrowings in foreign currencies JPMORGAN CHASE BANK 2.8 33,651 Subtotal 7,182,053 Bills sold Others 0.0 ~ 1.2 23,874 Call money Bank and others 0.0 ~ 6.3 818,889 Bonds sold under repurchase agreements Other financial institutions 0.7 ~ 12.7 5,372 Present value discount (27 ) Total 15,899,599 December 31, 2017 Lenders Interest rate (%) Amount Borrowings in local currency: Borrowings from The BOK The BOK 0.5 ~ 0.8 1,404,087 Borrowings from government funds Small Enterprise And Market Service and others 0.0 ~ 2.9 1,723,340 Others The Korea Development Bank and others 0.0 ~ 3.2 3,957,421 Subtotal 7,084,848 Borrowings in foreign currencies: Borrowings in foreign currencies The Export-Import 0.0 ~ 6.8 6,996,551 Offshore borrowings in foreign currencies Commonwealth Bank 1.8 28,285 Subtotal 7,024,836 Bills sold Others 0.0 ~ 1.2 36,953 Call money Bank and others 1.5 ~ 2.7 635,061 Bonds sold under repurchase agreements Other financial institutions 0.6 ~ 12.7 3,173 Present value discount (165 ) Total 14,784,706 (2) Details of debentures are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Interest rate Amount Interest rate Amount Face value of bond(*): Ordinary bonds 1.5 ~ 4.5 21,105,565 1.5 ~ 5.8 22,468,908 Subordinated bonds 3.0 ~ 12.6 5,006,632 3.4 ~ 12.6 4,781,301 Other bonds 1.9 ~ 17.0 676,144 1.6 ~ 17.0 649,615 Subtotal 26,788,341 27,899,824 Discounts on bonds (35,616 ) (30,173 ) Total 26,752,725 27,869,651 (*) Included debentures under fair value hedge relationships are 3,150,145 million Won and 3,089,751 million Won as of June 30, 2018 and December 31, 2017, respectively. Also, debentures under cash flow hedge amounting to 724,487 million Won and 694,548 million Won are included as of June 30, 2018 and December 31, 2017.

Provisions

Provisions	6 Months Ended
	Jun. 30, 2018
Provisions [Abstract]
Provisions	23. PROVISIONS (1) Details of provisions are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Asset retirement obligation 67,458 61,872 Provisions for guarantees (*1) 106,827 183,247 Provisions for unused commitments 101,874 66,115 Provisions for customer reward credits 46,735 40,445 Other provisions (*2) 63,480 58,791 Total 386,374 410,470 (*1) Provisions for guarantees includes provision for financial guarantee of 54,896 million Won and 71,697 million Won as of June 30, 2018 and December 31, 2017, respectively. (*2) Other provisions consist of provision for litigation and others. (2) Changes in provisions for guarantees and loan commitments are as follows (Unit: Korean Won in millions): 1) Provisions for guarantees For the six months ended June 30, 2018 Stage1 Stage2 Stage3 Total Beginning balance (*) 47,132 18,281 127,511 192,924 Replaced by 12-month 76 (76 ) — — Replaced with expected credit loss for the entire period (954 ) 58,894 (57,940 ) — Replaced with credit-impaired financial assets (21 ) (20 ) 41 — Provisions used (8,506 ) — — (8,506 ) Net reversal of unused amount (4,873 ) (46,344 ) (35,773 ) (86,990 ) Others 9,393 6 — 9,399 Ending balance 42,247 30,741 33,839 106,827 (*) The beginning balance was restated in accordance with IFRS 9. For the six months ended Beginning balance 238,117 Provisions provided 1,003 Provisions used (12,335 ) Reversal of provisions unused (45,971 ) Foreign currencies translation adjustments 20 Others 7,920 Ending balance 188,754 2) Provisions for unused commitment For the six months ended June 30, 2018 Stage1 Stage2 Stage3 Total Beginning balance (*) 75,232 27,875 1,878 104,985 Replaced by 12-month 6,262 (6,145 ) (117 ) — Replaced with expected credit loss for the entire period (2,543 ) 2,614 (71 ) — Replaced with credit-impaired financial assets (159 ) (325 ) 484 — Net provision(reversal) of unused amount (6,183 ) 3,356 (328 ) (3,155 ) Others 44 — — 44 Ending balance 72,653 27,375 1,846 101,874 (*) The beginning balance was restated in accordance with IFRS 9. For the six months ended Beginning balance 87,909 Provisions provided 491 Provisions used (42 ) Reversal of provisions unused (5,736 ) Foreign currencies translation adjustments (1 ) Ending balance 82,621 (3) Changes in asset retirement obligation are as follows (Unit: Korean Won in millions): For the six months 2018 2017 Beginning balance 61,872 58,076 Provisions provided 1,083 654 Provisions used (295 ) (416 ) Reversal of provisions unused (993 ) (727 ) Amortization 259 203 Increase in restoration costs and others 5,532 4,163 Ending balance 67,458 61,953 The amount of the asset retirement obligation is the present value of the best estimate of future expected recovery cost arising from leased premises as of June 30, 2018, discounted by appropriate discount rate. The expenditure of the recovery cost is expected to occur by the end of each premise’s lease period, and the Group has used average lease period of each category of leases terminated during the past years in order to rationally estimate the lease period. In addition, the Group used average amount of actual recovery cost for the past 3 years and the average inflation rate for last year in order to estimate future recovery cost. (4) Changes in other provisions are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Provisions for Other Total Beginning balance 40,445 58,791 99,236 Provisions provided 36,044 2,236 38,280 Provisions used (48,891 ) (2,199 ) (51,090 ) Reversal of unused amount — (40 ) (40 ) Foreign currencies translation adjustments — (7 ) (7 ) Transfer (*) 5,467 — 5,467 Others 13,670 4,699 18,369 Ending balance 46,735 63,480 110,215 (*) As the credits of the affiliates were transferred to the Group, the allowance for the provisions for customer reward credits increased for the six months ended June 30, 2018. For the six months ended June 30, 2017 Provisions for Other Total Beginning balance 22,093 22,282 44,375 Provisions provided 32,208 2,390 34,598 Provisions used (39,402 ) (9,013 ) (48,415 ) Reversal of unused amount — (40 ) (40 ) Foreign currencies translation adjustments — (146 ) (146 ) Transfer (*) 11,482 — 11,482 Amortization — 53 53 Others 5,667 128 5,795 Ending balance 32,048 15,654 47,702 (*) As the credits of the affiliates were transferred to the Group, the allowance for the provisions for customer reward credits increased for the six months ended June 30, 2017.

Net Defined Benefits Liability

Net Defined Benefits Liability (Asset)	6 Months Ended
	Jun. 30, 2018
Disclosure of defined benefit plans [Abstract]
Net defined benefit liability	24. NET DEFINED BENEFIT LIABILITY The characteristics of the Group’s defined benefit retirement pension plans characteristics are as follows: Employees and directors with one or more years of service are entitled to receive a payment upon termination of their employment, based on their length of service and rate of pay at the time of termination. The assets of the plans are measured at their fair value at the end of reporting date. The plan liabilities are measured using the projected unit method, which takes account of projected earnings increases, using actuarial assumptions that give the best estimate of the future cash flows that will arise under the plan liabilities. The Group is exposed to various risks through defined benefit retirement pension plan, and the most significant risks are as follows: Volatility of asset The defined benefit obligation was estimated with an interest rate calculated based on blue chip corporate bonds earnings. A deficit may occur if the rate of return of plan assets falls short of the interest rate. Decrease in profitability of blue chip bonds A decrease in profitability of blue chip bonds will be offset by some increase in the value of debt securities that the employee benefit plan owns but will bring an increase in the defined benefit obligation. Risk of inflation Defined benefit obligations are related to inflation rate; the higher the inflation rate is, the higher the level of liabilities. Therefore, deficit occurs in the system if an inflation rate increases. (1) Details of net defined benefit liability are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Defined benefit obligation 1,175,786 1,071,170 Fair value of plan assets (1,075,927 ) (1,027,906 ) Net defined benefit liability 99,859 43,264 (2) Changes in the carrying value of defined benefit obligation are as follows (Unit: Korean Won in millions): For the six months For the six months Beginning balance 1,071,170 984,381 Current service cost 72,460 73,564 Interest cost 15,797 13,144 Remeasurements 72,374 4,639 Foreign currencies translation adjustments 8 (121 ) Retirement benefit paid (57,109 ) (31,022 ) Curtailment or settlement — (10,076 ) Others 1,086 127 Ending balance 1,175,786 1,034,636 (3) Changes in the plan assets are as follows (Unit: Korean Won in millions): For the six months For the six months Beginning balance 1,027,906 990,653 Interest income 16,626 15,127 Remeasurements (9,088 ) (7,847 ) Employer’s contributions 96,273 18,000 Retirement benefit paid (55,790 ) (29,431 ) Curtailment or settlement — (10,396 ) Others — 43,113 Ending balance 1,075,927 1,019,219 (4) Plan assets wholly consist of time deposits as of June 30, 2018 and December 31, 2017, respectively. Among plan assets, realized returns on plan assets amount to 7,538 million Won and 7,280 million Won for the six months ended June 30, 2018 and 2017, respectively. Meanwhile, the contribution expected to be paid in the current accounting year amounts to 125,818 million Won. (5) Current service cost, net interest income, loss (gain) on the curtailment or settlement and remeasurements recognized in the consolidated statements of net income and total comprehensive income are as follows (Unit: Korean Won in millions): For the six months For the six months Current service cost 72,460 73,564 Net interest income (829 ) (1,983 ) Loss (gain) on the curtailment or settlement — 321 Cost recognized in net income 71,631 71,902 Remeasurements(*) 81,462 12,486 Cost recognized in total comprehensive income 153,093 84,388 (*) This is an amount before considering the tax effects. Retirement benefit service costs related to defined contribution plans amount to 1,304 million Won and 2,155 million Won for the six months ended June 30, 2018 and 2017, respectively. (6) Key actuarial assumptions used in defined benefit liability measurement are as follows: June 30, 2018 December 31, 2017 Discount rate 3.25% 3.18% Future wage growth rate 6.18% 6.18% Mortality rate Issued by Korea Insurance Issued by Korea Insurance Retirement rate Experience rate for each Experience rate for each The weighted average maturity of defined benefit liability is 12.94 years. (7) The sensitivity to actuarial assumptions used in the assessment of defined benefit obligation is as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Discount rate Increase by 1% point (124,157 ) (116,405 ) Decrease by 1% point 146,273 137,151 Future wage growth rate Increase by 1% point 145,794 136,707 Decrease by 1% point (125,567 ) (117,765 )

Other Financial Liabilities and

Other Financial Liabilities and Other Liabilities	6 Months Ended
	Jun. 30, 2018
Miscellaneous Liabilities [Abstract]
Disclosure of other financial liabilities and other liabilities	25. OTHER FINANCIAL LIABILITIES AND OTHER LIABILITIES Other financial liabilities and other liabilities are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Other financial liabilities: Accounts payable 9,021,786 4,692,320 Accrued expenses 1,809,499 2,049,861 Borrowings from trust accounts 3,999,899 3,271,817 Agency business revenue 258,497 344,591 Foreign exchange payables 604,344 590,667 Domestic exchange payables 4,229,125 1,309,646 Other miscellaneous financial liabilities 1,487,513 1,635,156 Present value discount (2,396 ) (1,597 ) Subtotal 21,408,267 13,892,461 June 30, 2018 December 31, 2017 Other liabilities: Unearned income 178,799 180,664 Other miscellaneous liabilities 124,114 103,317 Subtotal 302,913 283,981 Total 21,711,180 14,176,442

Derivatives

Derivatives	6 Months Ended
	Jun. 30, 2018
Disclosure of detailed information about hedges [Abstract]
Derivatives	26. DERIVATIVES (1) Derivative assets and derivative liabilities are as follows (Unit: Korean Won in millions): June 30, 2018 Nominal Assets Liabilities For fair For trading For cash flow For fair For trading Interest rate: Futures 272,778 — — — — — Swaps 143,307,983 12,395 218,551 — 34,540 232,719 Purchase options 660,000 — 10,897 — — — Written options 785,000 — — — — 11,731 Currency: Futures 371,529 — — — — — Forwards 80,082,126 — 1,200,200 — — 1,164,623 Swaps 56,427,354 — 806,790 32,965 — 750,377 Purchase options 2,635,551 — 36,079 — — — Written options 4,651,496 — — — — 49,352 Equity: Futures 124,009 — — — — — Swaps 435,790 — 3,021 — — 4,542 Purchase options 4,272,150 — 115,210 — — — Written options 5,661,146 — — — — 163,966 Others: Futures 965 — — — — — Forward 5,618 — — — — — Swaps 8,081 — 463 — — 440 Total 299,701,576 12,395 2,391,211 32,965 34,540 2,377,750 December 31, 2017 Nominal Assets Liabilities For fair For trading For cash flow For fair For trading Interest rate: Futures 75,845 — — — — — Swaps 130,197,378 59,272 223,935 — 12,103 253,972 Purchase options 630,000 — 12,346 — — — Written options 795,000 — — — — 12,869 December 31, 2017 Nominal Assets Liabilities For fair For trading For cash flow For fair For trading Currency: Futures 318,217 — — — — — Forwards 72,526,956 — 1,314,368 — — 1,375,799 Swaps 48,176,306 — 1,352,924 55,651 — 1,347,905 Purchase options 2,291,154 — 64,267 — — — Written options 4,038,237 — — — — 58,687 Equity: Futures 91,436 — — — — — Swaps 15,000 — 103 — — 10 Purchase options 5,060,706 — 146,775 — — — Written options 4,504,290 — — — — 99,770 Others: Futures — — — — — — Swaps 7,805 — 1,057 — — 1,037 Purchase options — — — — — — Written options 5,000 — — — — 100 Total 268,733,330 59,272 3,115,775 55,651 12,103 3,150,149 Derivatives held for trading are classified into financial assets at FVTPL (Note 7) and financial liabilities at FVTPL (Note 20), and derivatives held for hedging are presented as a separate line item in the consolidated statements of financial position. (2) Overview of the Group’s hedge accounting 1) Fair value hedge As of the current period end, the Group has applied fair value hedge on fixed interest rate foreign currency denominated debentures amounting to 3,150,145 million Won. The purpose of the hedging is to avoid fair value volatility risk of fixed interest rate foreign currency denominated debentures derived from fluctuations of market interest rate, and as such the Group entered into interest rate swap agreements designated as hedging instruments. The Group entered into interest rate swap agreements to manage its exposure to interest rate risk and designated as hedging instruments. Pursuant to the interest rate swap agreement, hedge ratio is determined by matching the nominal value to the face value of the hedging instrument. In this hedging relationship, only the market interest rate fluctuation, which is the most significant part of the fair value change of the hedged item, is designated as the hedged risk, and other risk factors including credit risk are not included in the hedged risk. Therefore, the ineffective portion of the hedge could arise from fluctuations in the timing of the cash flow of the hedged item, the change in the total amount and price of the hedged item, or significant credit risk fluctuation of either party of the hedged item. The interest rate swap agreements and the hedged items are subject to fluctuations in the underlying market rate of interest and the Group expects the value of the interest rate swap contract and the value of the hedged item to generally change in the opposite direction. The fair value of the interest rate swap at the end of the reporting period is determined by discounting future cash flows estimated using the yield curve at the end of the reporting period and the credit risk embedded in the contract and the average interest rate is determined based on the outstanding balance at the end of the reporting period. The variable interest rate applied to the interest rate swap is USD Libor 3M (6M) plus spread. In accordance with the terms of each interest rate swap contract designated as a hedging instrument, the Group receives interest at a fixed interest rate and pays interest at a variable interest rate. 2) Cash Flow Hedge As of the current period end, the Group has applied Cash Flow hedge on foreign currency denominated bonds amounting to 724,487 million Won. The Group’s objectives of hedging are to (1) Mitigate risks of cash flow fluctuation from principal and interest of variable interest rate debentures denominated in foreign currency, which arise from changes in foreign exchange rate and market interest rate; and (2) Mitigate the risks of cash flow fluctuation from principal and interest of fixed-interest rate debentures denominated in foreign currency, which arise from changes in foreign exchange rates. The Group has designated foreign currency swap contracts as hedging instruments in order to achieve such objectives. (3) The nominal amounts of the hedging instrument as of June 30, 2018 are as follows (Unit: USD, SGD): 1 year or less 1 year to 5 years More than 5 years Total Fair value hedging derivatives Interest rate risk Interest rate swap (USD) 500,000,000 1,350,000,000 1,000,000,000 2,850,000,000 Cash flow hedge Foreign currencies translation risk and interest rate risk Currency swap (USD) 50,000,000 450,000,000 — 500,000,000 Foreign currencies translation risk Currency swap (SGD) — 204,000,000 — 204,000,000 (4) The average interest rate and average currency rate of the hedging instrument as of June 30, 2018 are as follows: Average interest rate and average currency rate Fair value hedging derivatives Interest rate risk Interest rate swaps (USD) Fixed 3.98% receipt and 3.96% floating paid Cash flow hedge Foreign currencies translation risk and interest rate risk Currency swap (USD) USD 2.65% receipt, KRW 1.71% paid, USD/KRW = 1,173 Won Foreign currencies translation risk Currency swap (SGD) SGD 1.91% receipt, KRW 1.98% paid, SGD/KRW = 828 Won (5) The amounts related to items designated as hedging instruments as of June 30, 2018 are as follows (Unit: Korean Won in millions, USD, SGD): Carrying amounts of Line item in the Nominal amounts of Assets Liabilities Changing in fair Fair value hedge Interest rate risk Interest rate swaps USD2,850,000,000 12,395 34,540 Derivative (62,246 ) Cash flow hedge Foreign currencies translation risk and interest rate risk Currency swap USD500,000,000 — 27,594 Derivative 22,013 Foreign currencies translation risk Currency swap SGD204,000,000 — 5,372 Derivative 672 (6) Details of carrying amount to hedged and amount adjusted due to hedge accounting as of June 30, 2018 are as follows (Unit: Korean won in millions): Carrying amounts of Accumulated amount of Line item in the Changing in Cash flow Assets Liabilities Assets Liabilities Fair value hedging Interest rate risk Debenture — 3,150,145 — 60,732 Debentures 66,455 — Cash flow hedge Foreign currencies translation risk and interest rate risk Debenture — 558,258 — — Debentures (21,725 ) (1,665 ) Foreign currencies translation risk Debenture — 166,229 — — Debentures (505 ) (3,770 ) (*) Amount after tax deduction (7) Amounts recognized in profit or loss due to the ineffective portion of fair value hedges during the current period are as follows (Unit: Korean Won in millions): Hedge ineffectiveness Line item in the profit that Fair value hedge Interest rate risk 4,209 Other net operating (8) Reclassification of profit or loss from other comprehensive income and equity related to cash flow hedges is as follows (Unit: Korean Won in millions): Changes in Hedge Line item in the Amounts Line item Cash flow hedge Foreign currencies translation risk and interest rate risk 22,043 (30 ) Other net 25,049 Other net Foreign currencies translation risk 672 — Other net 3,894 Other net

Deferred Day 1 Profit or Loss

Deferred Day 1 Profit or Loss	6 Months Ended
	Jun. 30, 2018
Disclosure Of Day One Profit Or Loss [Abstract]
Disclosure of day one profit or loss	27. DEFERRED DAY 1 PROFITS OR LOSSES Changes in deferred day 1 profits or losses are as follows (Unit: Korean Won in millions): For the six months 2018 2017 Beginning balance 7,416 13,422 New transactions 20,820 500 Amounts recognized in losses (3,000 ) (3,613 ) Ending balance 25,236 10,309 In case some variables to measure fair values of financial instruments are not observable or available in the market, valuation techniques are utilized to evaluate such financial instruments. Those financial instruments are recorded at the fair value produced by the valuation techniques as at the time of acquisition, even though there are difference noted between the transaction price and the fair value. The table above presents the difference yet to be realized as profit or losses.

Capital Stock and Capital Surpl

Capital Stock and Capital Surplus	6 Months Ended
	Jun. 30, 2018
Disclosure Of Issued Capital And Miscellaneous Equity [Abstract]
Disclosure of issued capital and miscellaneous equity	28. CAPITAL STOCK AND CAPITAL SURPLUS (1) The number of shares authorized and others are as follows: June 30, 2018 December 31, 2017 Shares of common stock authorized 5,000,000,000 Shares 5,000,000,000 Shares Par value 5,000 Won 5,000 Won Shares of common stock issued 676,000,000 Shares 676,000,000 Shares Capital stock 3,381,392 million Won 3,381,392 million Won (2) There is no change to be disclosed in numbers of issued and outstanding shares of common stock for the six months ended June, 2018 and 2017. (3) Details of capital surplus are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Capital in excess of par value 269,533 269,533 Other capital surplus 16,352 16,347 Total 285,885 285,880

Hybrid Securities

Hybrid Securities	6 Months Ended
	Jun. 30, 2018
Hybrid Instruments [Abstract]
Disclosure Of Hybrid Securities	29. HYBRID SECURITIES The bond-type hybrid securities classified as owner’s equity are as follows (Unit: Korean Won in millions): Issue date Maturity Interest rate June 30, December 31, Securities in local currency June 20, 2008 June 20, 2038 7.7 — 255,000 April 25, 2013 April 25, 2043 4.4 500,000 500,000 November 13, 2013 November 13, 2043 5.7 200,000 200,000 December 12, 2014 December 12, 2044 5.2 160,000 160,000 June 3, 2015 June 3, 2045 4.4 240,000 240,000 Securities in foreign currencies June 10, 2015 June 10, 2045 5.0 559,650 559,650 September 27, 2016 — 4.5 553,450 553,450 May 16, 2017 — 5.3 562,700 562,700 Issuance cost (12,544 ) (12,912 ) Total 2,763,256 3,017,888 The hybrid securities mentioned above are either without a maturity date or its maturity can be extended indefinitely at the maturity date without change of terms. Further, if a resolution is passed not to pay dividends on common stock, interest payments on the hybrid securities may be not occur.

Other Equity

Other Equity	6 Months Ended
	Jun. 30, 2018
Disclosure Of Other Equity [Abstract]
Disclosure of other equity	30. OTHER EQUITY (1) Details of other equity are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Accumulated other comprehensive loss: Net gain or loss on valuation of financial assets at FVTOCI (46,746 ) — Gain on valuation of AFS financial assets — 301,930 Gain (loss) on financial liabilities at fair value through profit or loss designated as upon initial recognition due to own credit risk 29 — Share of other comprehensive loss of joint ventures and associates (1,446 ) (1,251 ) Loss on foreign currency translation of foreign operations (206,037 ) (242,700 ) Remeasurement loss related to defined benefit plan (211,838 ) (152,624 ) Gain (loss) on valuation of cash flow hedges (5,436 ) 777 Equity related to assets held for sale (564 ) 4,145 Subtotal (472,038 ) (89,723 ) Treasury shares (34,113 ) (34,113 ) Other capital adjustments (1,607,647 ) (1,815,438 ) Total (2,113,798 ) (1,939,274 ) (2) Changes in the accumulated other comprehensive loss are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Beginning Increase Reclassification Income tax Ending Net gain or loss on valuation of financial assets at FVTOCI (88,906 ) 58,846 (694 ) (15,992 ) (46,746 ) Gain (loss) on financial liabilities at fair value through profit or loss designated as upon initial recognition due to own credit risk (96 ) 172 — (47 ) 29 Share of other comprehensive gain (loss) of joint ventures and associates (2,656 ) 1,669 — (459 ) (1,446 ) Gain (loss) on foreign currency translation of foreign operations (242,806 ) 50,717 — (13,948 ) (206,037 ) Remeasurement gain (loss) related to defined benefit plan (152,358 ) (82,041 ) — 22,561 (211,838 ) Gain (loss) on valuation of cash flow hedges 777 (8,570 ) — 2,357 (5,436 ) Transfer to non-current 4,145 (564 ) (4,145 ) — (564 ) Total (481,900 ) 20,229 (4,839 ) (5,528 ) (472,038 ) (*1) The beginning balance was restated in accordance with IFRS 9. (*2) Net gain or loss on valuation of financial assets at FVTOCI included the 1,500 million Won transfer to retained earnings due to disposal of equity securities. For the six months ended June 30, 2017 Beginning Increase Reclassification Income tax Ending Gain (loss) on valuation of AFS financial assets 386,981 46,479 (81,114 ) 5,602 357,948 Share of other comprehensive income (loss) of joint ventures and associates (1,863 ) 2,038 — (531 ) (356 ) Gain (loss) on foreign currency translation of foreign operations (48,353 ) (81,571 ) — 17,627 (112,297 ) Remeasurement gain (loss) related to defined benefit plan (163,397 ) (12,642 ) — 3,020 (173,019 ) Gain (loss) on valuation of cash flow hedges — (1,947 ) — 421 (1,526 ) Total 173,368 (47,643 ) (81,114 ) 26,139 70,750 (*) For the change in gain (loss) on valuation of AFS financial assets, “increase (decrease)” represents change due to the valuation during the period, and “reclassification adjustments” represents disposal or recognition of impairment losses on AFS financial assets.

Retained Earnings

Retained Earnings	6 Months Ended
	Jun. 30, 2018
Retained Earnings Note Disclosure [Abstract]
Disclosure of retained earnings accumulated deficit	31. RETAINED EARNINGS (1) Details of retained earnings are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Legal reserve Earned surplus reserve 1,857,754 1,729,754 Other legal reserve 46,384 45,668 Subtotal 1,904,138 1,775,422 Voluntary reserve Business rationalization reserve 8,000 8,000 Reserve for financial structure improvement 235,400 235,400 Additional reserve 7,759,804 7,418,806 Regulatory reserve for credit loss 2,578,457 2,438,191 Revaluation reserve 715,860 751,964 Other voluntary reserve — 11,700 Subtotal 11,297,521 10,864,061 Conversion of loss on disposal of equity securities at FVTOCI to retained earnings (424 ) — Derecognition of the credit risk on financial liabilities designated at FVTPL 5 — Retained earnings before appropriation 3,272,213 2,980,523 Total 16,473,453 15,620,006 i. Earned surplus reserve In accordance with the Banking Act, earned surplus reserve is appropriated at least one tenth of the earnings after tax on every dividend declaration, not exceeding the paid in capital. This reserve may not be used other than for offsetting a deficit or transferring to capital. ii. Other legal reserve Other legal reserves were appropriated in the branches located in Japan, Vietnam and Bangladesh according to the banking laws of Japan, Vietnam and Bangladesh, and may be used to offset any deficit incurred in those branches. iii. Business rationalization reserve Pursuant to the Restriction of Special Taxation Act, the Group was previously required to appropriate, as a reserve for business rationalization, amounts equal to tax reductions arising from tax exemptions and tax credits up to December 31, 2001. The requirement was no longer effective from 2002. iv. Reserve for financial structure improvement From 2002 to 2014, the Finance Supervisory Services recommended banks in Korea to appropriate at least 10 percent of net income after accumulated deficit for financial structure improvement, until tangible common equity ratio equals 5.5 percent. But this reserve is not available for payment of cash dividends; however, it can be used to reduce a deficit or be transferred to capital. The reserve and appropriation are an Autonomous judgment matter of the Group since 2015. v. Additional reserve Additional reserve was appropriated for capital adequacy and other management purpose. vi. Regulatory reserve for credit loss In accordance with Article 29 of the Regulation on Supervision of Banking Business (“RSBB”), if provisions for credit loss under IFRS for the accounting purpose are lower than provisions under RSBB, the Group discloses such short fall amount as regulatory reserve for credit loss. vii. Revaluation reserve Revaluation reserve is the amount of limited dividends set by the board of directors to be the recognized as complementary capital when the gain or loss occurred in the property revaluation by adopting IFRS. (2) Changes in retained earnings are as follows (Unit: Korean Won in millions): For the six months ended June 30 2018 (*) 2017 Beginning balance 15,797,097 14,611,566 Net attributable to owners 1,305,878 1,098,361 Dividends on common stock (336,636 ) (269,308 ) Dividends on hybrid securities (75,603 ) (90,823 ) Loss on disposal of equity securities at FVTOCI (424 ) — Derecognition of the credit risk on financial liabilities designated at FVTPL 5 — Capital adjustments due to appropriation of retained earnings (216,864 ) — Ending balance 16,473,453 15,349,796 (*) The beginning balance as of 2018 was restated in accordance with IFRS 9.

Dividends

Dividends	6 Months Ended
	Jun. 30, 2018
Dividends [Abstract]
Dividends	32. DIVIDENDS At the shareholders’ meeting on March 23, 2018, dividend payment for the year ended December 31, 2017 amounting to 336,636 million Won (500 Won per share) was approved and paid for the six months ended June 30, 2018.

Net Interest Income

Net Interest Income	6 Months Ended
	Jun. 30, 2018
Interest Revenue (Expense), Net [Abstract]
Disclosure of interest income (expense)	33. NET INTEREST INCOME (1) Interest income recognized is as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Financial assets at FVTPL (IFRS 9) 13,367 28,537 — — Financial assets at FVTPL (IAS 39) — — 13,074 26,806 Financial assets at FVTOCI 62,170 119,446 — — AFS financial assets — — 67,667 144,067 Securities at amortized cost 87,587 168,789 — — HTM financial assets — — 74,690 149,673 Financial assets at amortized cost: Interest on due from banks 28,323 61,461 — — Interest on loans 2,170,291 4,251,497 — — Interest of other receivables 6,931 13,686 — — Subtotal 2,205,545 4,326,644 — — Loans and receivables: Interest on due from banks — — 20,182 41,403 Interest on loans — — 1,921,359 3,810,008 Interest of other receivables — — 8,836 17,627 Subtotal — — 1,950,377 3,869,038 Total 2,368,669 4,643,416 2,105,808 4,189,584 (2) Interest expense recognized is as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Interest on deposits due to customers 704,007 1,358,964 586,051 1,174,384 Interest on borrowings 70,519 129,929 57,666 115,548 Interest on debentures 174,890 346,948 154,445 305,804 Other interest expense 21,930 43,101 20,070 43,528 Total 971,346 1,878,942 818,232 1,639,264

Net Fees and Commissions Income

Net Fees and Commissions Income	6 Months Ended
	Jun. 30, 2018
Fee and commission income (expense) [Abstract]
Net Fees And Commissions Income	34. NET FEES AND COMMISSIONS INCOME (1) Details of fees and commissions income recognized are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Fees and commissions received (*) 169,171 346,925 163,688 336,322 Fees and commissions received for provision of guarantee 14,660 30,263 15,911 31,700 Fees and commissions received on project financing 10,528 16,945 4,614 6,334 Fees and commissions received on credit card 283,407 556,984 268,887 527,566 Fees and commissions received on securities 23,767 50,238 19,757 40,267 Other fees and commissions received 53,867 111,651 33,424 71,704 Total 555,400 1,113,006 506,281 1,013,893 (*) Fees and commissions received include fees income from agency commission, fees income from electronic finance, fees income related to loan, fees for import letter of credit dealing, commission received on foreign exchange and others. (2) Details of fees and commissions expense incurred are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Fees and commissions paid 41,532 80,866 41,930 73,167 Credit card commission 213,887 425,204 200,275 400,349 Brokerage commission 934 1,268 121 348 Others 1,700 3,013 1,207 2,329 Total 258,053 510,351 243,533 476,193

Dividend Income

Dividend Income	6 Months Ended
	Jun. 30, 2018
Disclosure Of Revenue From Dividends [Abstract]
Disclosure of revenue from dividends	35. DIVIDEND INCOME (1) Details of dividend income recognized are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Financial assets at FVTPL (IFRS 9) 12,210 31,860 — — Financial assets at FVTPL (IAS 39) — — 47 190 Financial assets at FVTOCI 1,941 17,844 — — AFS financial assets — — 19,570 59,255 Total 14,151 49,704 19,617 59,445 (2) Details of dividends related to financial assets at FVTOCI are as follows (Unit: Korean Won in millions): Six month ended Dividend income recognized from assets held Equity securities 17,570 Dividend income recognized in assets derecognized 274 Total 17,844

Net gain or loss on financial i

Net gain or loss on financial instruments at fair value through profit or loss mandatorily measured at fair value (IFRS 9 and IAS 39)	6 Months Ended
	Jun. 30, 2018
Disclosure of gains (losses) on financial instruments at fair value through profit or loss [Abstract]
Net gain or loss on financial instruments at fair value through profit or loss mandatorily measured at fair value (IFRS 9 and IAS 39)	36. NET GAIN OR LOSS ON FINANCIAL INSTRUMENTS AT FAIR VALUE THROUGH PROFIT OR LOSS MANDATORILY MEASURED AT FAIR VALUE (IFRS 9 AND IAS 39) (1) Details of gains or losses related to net gain or loss on financial instruments at FVTPL (IFRS 9 and IAS 39) are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Gains on financial assets at fair value through profit or loss mandatorily measured at fair value 70,116 114,146 — — Gains (losses) on financial instruments held for trading — — 36,266 (60,186 ) Gains (losses) on financial instrument at fair value through profit or loss designated as upon initial recognition (2,423 ) 2,877 — — Losses on financial instruments at fair value through profit or loss designated as upon initial recognition — — (24,200 ) (86,223 ) Total 67,693 117,023 12,066 (146,409 ) (2) Details of net gain or loss on financial instrument at fair value through profit or loss mandatorily measured at fair value and financial assets held for trading are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Financial assets at FVTPL (financial assets held for trading) Securities Gain on valuation 36,982 81,861 1,055 5,895 Gain on disposals 18,885 22,377 3,936 9,860 Loss on valuation (11,957 ) (23,795 ) (2,785 ) (6,511 ) Loss on disposals (7,481 ) (9,180 ) (1,308 ) (2,057 ) Subtotal 36,429 71,263 898 7,187 Loans Gain on valuation 373 3,191 — — Loss on valuation (107 ) (127 ) — — Subtotal 266 3,064 — — Other financial assets Gain on valuation 228 1,969 1,495 3,071 Gain on disposals 143 405 814 933 Loss on valuation (320 ) (2,193 ) (1,971 ) (3,590 ) Loss on disposals (11 ) (83 ) (211 ) (234 ) Subtotal 40 98 127 180 Total of financial assets held for trading 36,735 74,425 1,025 7,367 2018 2017 Three months Six months Three months Six months Derivatives (for trading) Interest rates derivatives Gain on transactions and valuation 231,372 600,362 201,637 433,349 Loss on transactions and valuation (247,381 ) (594,525 ) (198,170 ) (421,734 ) Subtotal (16,009 ) 5,837 3,467 11,615 Currency derivatives Gain on transactions and valuation 2,546,154 3,535,106 (94,206 ) 3,773,565 Loss on transactions and valuation (2,502,934 ) (3,505,890 ) 105,055 (3,943,609 ) Subtotal 43,220 29,216 10,849 (170,044 ) Equity derivatives Gain on transactions and valuation 115,712 249,364 92,302 302,927 Loss on transactions and valuation (109,288 ) (244,063 ) (71,116 ) (211,551 ) Subtotal 6,424 5,301 21,186 91,376 Other derivatives Gain on transactions and valuation 2,142 2,790 2,295 12,312 Loss on transactions and valuation (2,396 ) (3,423 ) (2,556 ) (12,812 ) Subtotal (254 ) (633 ) (261 ) (500 ) Total of derivatives (for trading) 33,381 39,721 35,241 (67,553 ) Total 70,116 114,146 36,266 (60,186 ) (3) Details of net gain or loss on financial instrument at fair value through profit or loss designated as upon initial recognition are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Gain (loss) on equity-linked securities: Loss on disposals of equity-linked securities (1,203 ) (1,534 ) (3,686 ) (15,877 ) Gain (loss) on valuation of equity-linked securities (2,164 ) 2,814 (20,667 ) (69,714 ) Subtotal (3,367 ) 1,280 (24,353 ) (85,591 ) Loss on other securities: Loss on valuation of other securities — — (114 ) (16 ) Gain (loss) on other financial instruments: Gain (loss) on valuation of other financial instruments 944 1,597 267 (616 ) Total (2,423 ) 2,877 (24,200 ) (86,223 )

Gains (losses) on financial ass

Gains (losses) on financial assets at fair value through other comprehensive income and available-for-sale financial assets	6 Months Ended
	Jun. 30, 2018
Gains (losses) on financial assets at fair value through other comprehensive income and available-for-sale financial assets [Abstract]
Gains (losses) on financial assets at fair value through other comprehensive income and available-for-sale financial assets	37. NET GAIN OR LOSS ON FINANCIAL ASSETS AT FVTOCI AND AFS FINANCIAL ASSETS Details of net gain on financial assets at FVTOCI and AFS financial assets recognized are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Gains on redemption of securities 11 16 220 547 Gains on transaction of securities 464 1,271 95,019 116,262 Impairment losses on securities — — (6,852 ) (12,637 ) Total 475 1,287 88,387 104,172

Impairment Losses Due to Credit

Impairment Losses Due to Credit Loss	6 Months Ended
	Jun. 30, 2018
Disclosure of impairment loss and reversal of impairment loss [Abstract]
Impairment Losses Due To Credit Loss	38. REVERSAL OF ALLOWANCE FOR (IMPAIRMENT LOSSES DUE TO) CREDIT LOSS Reversal of allowance for (Impairment losses due to) credit loss are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Reversal of credit loss on financial assets at FVTOCI (679 ) (459 ) — — Reversal of credit loss on securities at amortized cost losses (199 ) (191 ) — — Provision for credit loss on loans and other financial assets at amortized cost 76,699 (61,057 ) — — Impairment losses due to credit loss — — (211,842 ) (333,976 ) Reversal of provision on guarantee 76,354 86,990 16,071 44,968 Reversal of provision on (provision for) loan commitment (1,502 ) 3,155 (8,715 ) 5,245 Total 150,673 28,438 (204,486 ) (283,763 )

General administrative expenses

General administrative expenses and other operating income (expense)	6 Months Ended
	Jun. 30, 2018
Disclosure of general administrative expenses and other operating income (expense) [Abstract]
Disclosure of general administrative expenses and other operating income (expense)	39. GENERAL ADMINISTRATIVE EXPENSES AND OTHER NET OPERATING INCOME (EXPENSES) (1) Details of general and administrative expenses recognized are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Salaries Short term employee benefits Salaries 341,645 644,663 326,034 654,191 Employee benefits 108,933 213,627 114,170 213,600 Retirement benefit service costs 36,610 72,936 36,972 74,057 Termination 20,994 20,994 5,477 5,477 Subtotal 508,182 952,220 482,653 947,325 2018 2017 Three months Six months Three months Six months Depreciation and amortization 52,222 99,698 45,380 94,927 Other general and administrative expenses Rent 79,546 159,126 76,297 156,708 Taxes and public dues 38,275 67,385 34,077 63,178 Service charges 52,807 104,970 47,611 96,418 Computer and IT related 21,704 43,581 16,089 30,477 Telephone and communication 16,819 33,729 16,111 31,590 Operating promotion 9,339 19,768 10,003 21,053 Advertising 13,808 20,493 22,434 29,880 Printing 1,928 3,892 2,095 4,237 Traveling 2,679 6,034 2,920 6,024 Supplies 1,737 3,223 1,517 3,117 Insurance premium 1,961 4,002 1,956 4,169 Reimbursement 4,964 5,902 4,710 9,177 Maintenance 3,672 8,027 3,331 6,882 Water, light, and heating 2,809 7,203 2,883 7,146 Vehicle maintenance 2,379 4,594 2,602 4,964 Others 12,823 23,491 11,488 21,155 Subtotal 267,250 515,420 256,124 496,175 Total 827,654 1,567,338 784,157 1,538,427 (2) Details of other operating income recognized are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Gains on transaction of foreign exchange 157,245 847,397 619,297 1,698,987 Gains on disposal of loans and receivables (*1) — — 14,861 201,860 Gains related to derivatives 26,373 28,943 11,592 11,656 Gains on fair value hedged items 18,861 66,555 (7,094 ) 11,860 Others (*2) 1,741 17,522 5,813 68,668 Total 204,220 960,417 644,469 1,993,031 (*1) Gain on disposal of loan and receivables occurred for the six month ended June 30, 2018 was presented into a separate account for gain related to financial assets at amortized cost in accordance with the adoption of IFRS 9. (*2) Other income includes such income amounting to 28,800 million Won for the six months ended June 30, 2017, respectively, that the Group recognized for it is to receive from other creditor financial institutions in accordance with the creditor financial institutions committee agreement. (3) Details of other operating expenses recognized are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Losses on transactions of foreign exchange 114,971 726,348 534,740 1,374,764 KDIC deposit insurance premium 79,585 156,765 77,146 150,256 Contribution to miscellaneous funds 73,849 146,781 71,927 144,262 Losses (Gains) on disposals of loans and receivables (*1) — — (40 ) 28 Losses (Gains) related to derivatives 13,059 62,366 (16,441 ) 31,131 Losses on fair value hedged items — — 15,820 15,846 Others (*2) 45,707 87,571 38,584 75,554 Total 327,171 1,179,831 721,736 1,791,841 (*1) Loss on disposal of loan and receivables occurred for the six month ended June 30, 2018 was presented into a separate account for loss related to financial assets at amortized cost in accordance with the adoption of IFRS 9. (*2) Other expense includes such expenses amounting to 1,412 million Won and 3,325 million Won for the six months ended June 30, 2018 and 2017, respectively, which are related to the Group’s expected payments to other creditor financial institutions in accordance with the creditor financial institutions committee agreement. In addition, ‘Other expense’ for the six months ended June 30, 2018 and 2017 includes 25,179 million Won and 24,443 million Won, respectively, of intangible asset amortization expense.

Other non-operating income (exp

Other non-operating income (expense)	6 Months Ended
	Jun. 30, 2018
Other non-operating income (expense) [Abstract]
Other non-operating income (expense)	40. OTHER NON-OPERATING (1) Details of gains or losses on valuation of investments in joint ventures and associates are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Gain on valuation 10,687 15,347 (10,061 ) 3,316 Loss on valuation (3,006 ) (16,809 ) 521 (62,271 ) Impairment loss — — (5,323 ) (5,323 ) Total 7,681 (1,462 ) (14,863 ) (64,278 ) (2) Details of other non-operating 2018 2017 Three months Six months Three months Six months Other non-operating 23,345 39,041 30,411 77,185 Other non-operating (21,947 ) (43,762 ) (18,714 ) (67,187 ) Total 1,398 (4,721 ) 11,697 9,998 (3) Details of other non-operating 2018 2017 Three months Six months Three months Six months Rental fee income 1,687 3,203 1,880 3,700 Gains on disposal of investments in joint ventures and associates — — 4,466 32,886 Gains on disposal of premises and equipment, intangible assets and other assets 15,760 17,037 1,494 1,675 Reversal of impairment loss of premises and equipment, intangible assets and other assets 1 341 — 32 Others 5,897 18,460 22,571 38,892 Total 23,345 39,041 30,411 77,185 (4) Details of other non-operating 2018 2017 Three months Six months Three months Six months Depreciation on investment properties 1,004 2,010 992 1,991 Interest expense of rent leasehold deposits 150 292 105 223 Losses on disposal of investment in joint ventures and associates — 2,931 46 27,730 Losses on disposal of premises and equipment, intangible assets and other assets 167 221 271 608 Impairment losses of premises and equipment, intangible assets and other assets 2 2 40 160 Donation 8,551 22,042 10,426 14,980 Others 12,073 16,264 6,834 21,495 Total 21,947 43,762 18,714 67,187

Income Tax Expense

Income Tax Expense	6 Months Ended
	Jun. 30, 2018
Major components of tax expense (income) [Abstract]
Income Tax Expense	41. INCOME TAX EXPENSE (1) Details of income tax expenses are as follows (Unit: Korean Won in millions): For the six months 2018 2017 Current tax expense Current tax expense in respect of the current period 231,393 284,030 Adjustments recognized in the current period in relation to the current tax of prior periods (3,632 ) (4,919 ) Subtotal 227,761 279,111 Deferred tax expense Deferred tax assets (liabilities) relating to the origination and reversal of temporary differences 182,515 13,889 Deferred tax charged directly to equity (378 ) 27,933 Others (tax effect charged directly to equity due to the adoption of IFRS 9) 75,318 — Subtotal 257,455 41,822 Income tax expense 485,216 320,933 (2) Income tax expense reconciled to net income before income tax expense is as follows (Unit: Korean Won in millions): For the six months 2018 2017 Net income before income tax expense 1,801,532 1,429,948 Tax calculated at statutory tax rate (*) 490,240 345,585 Adjustments Effect of income that is exempt from taxation (19,695 ) (32,683 ) Effect of expense not deductible in determining taxable profit 9,395 9,624 Adjustments recognized in the current period in relation to the current tax of prior periods (3,632 ) (4,919 ) Others 8,908 3,326 Subtotal (5,024 ) (24,652 ) Income tax expense 485,216 320,933 Effective tax rate 26.9 % 22.4 % (*) The applicable income tax rate; 1) 11% for below 200 million Won, 2) 22% for above 200 million Won and below 20 billion Won, 3) 24.2% for above 20 billion Won and below 300 billion Won, 4) 27.5% for above 300 billion Won. (3) Details of accumulated deferred tax charged directly to equity are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Net gain on valuation of financial assets at FVTOCI 18,568 — Loss on valuation of AFS securities — (114,169 ) Share of other comprehensive gain (loss) of joint ventures and associates 378 (954 ) Foreign currency translation of foreign operations 6,852 15,855 Remeasurements of the net defined benefit liability 78,685 56,317 Gain (loss) on cash flow hedge 1,735 (248 ) Total 106,218 (43,199 )

Earnings per Share (EPS)

Earnings per Share (EPS)	6 Months Ended
	Jun. 30, 2018
Earnings per share [Abstract]
Earnings Per Share (Eps)	42. EARNINGS PER SHARE (“EPS”) Basic EPS is calculated by dividing net income by weighted average number of common shares outstanding (Unit: Korean Won in millions, except for EPS and number of shares): 2018 2017 Three months Six months Three months Six months Net income attributable to Owners 716,142 1,305,878 460,888 1,098,361 Dividends to hybrid securities (37,748 ) (75,603 ) (41,557 ) (90,823 ) Net income attributable to common shareholders 678,394 1,230,275 419,331 1,007,538 Weighted average number of common shares outstanding 673 shares 673 shares 673 shares 673 shares Basic EPS 1,008 1,828 623 1,497 Diluted EPS is equal to basic EPS because there is no dilution effect for the three and six months ended June 30, 2018 and 2017.

Contingent Liabilities and Comm

Contingent Liabilities and Commitments	6 Months Ended
	Jun. 30, 2018
Disclosure of contingent liabilities [Abstract]
Contingent Liabilities And Commitments	43. CONTINGENT LIABILITIES AND COMMITMENTS (1) Details of guarantees are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Confirmed guarantees Guarantee for loans 141,193 157,299 Acceptances 333,365 320,519 Guarantees in acceptances of imported goods 106,675 108,238 Other confirmed guarantees 5,981,767 6,288,965 Sub-total 6,563,000 6,875,021 Unconfirmed guarantees Local letter of credit 365,302 383,117 Letter of credit 3,207,797 3,637,787 Other unconfirmed guarantees 936,971 505,689 Sub-total 4,510,070 4,526,593 Commercial paper purchase commitments and others 1,299,503 1,458,101 Total 12,372,573 12,859,715 (2) Details of loan commitments and others are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Loan commitments 98,251,006 80,760,325 Other commitments 5,942,784 4,546,090 (3) Litigation case Legal cases where the Group is involved are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 As plaintiff As defendant As plaintiff As defendant Number of cases (*) 68 cases 161 cases 83 cases 155 cases Amount of litigation 443,234 256,147 413,267 244,767 Provisions for litigations 19,887 9,277 (*) The number of lawsuits as of June 30, 2018 and December 31, 2017 does not include fraud lawsuits, etc. and those lawsuits that are filed only to extend the statute of limitation. (4) Other The Group provides settlement services for payments in Korean Won to facilitate trade transactions between Korea and Iran. In connection with these services, the Group is currently being investigated by US government agencies including US prosecutors (United States Attorney’s Office and New York State Attorney General’s Office) as to whether the Group has violated United States laws by participating in prohibited transactions involving countries sanctioned by the US.

Related party transactions

Related party transactions	6 Months Ended
	Jun. 30, 2018
Disclosure of transactions between related parties [Abstract]
Related Party Transactions	44. RELATED PARTY TRANSACTIONS Related parties of the Group as of June 30, 2018, assets and liabilities recognized, guarantees and commitments, and major transactions with related parties for the six months ended June 30, 2018 and 2017 are as follows: (1) Related parties Related parties Associates Kumho Tire Co., Inc., Woori Service Networks Co., Ltd., Korea Credit Bureau Co., Ltd., Korea Finance Security Co., Ltd., Chin Hung International Inc., STX Corporation, 2016KIF-IMM (2) Assets and liabilities from transactions with related parties are as follows (Unit: Korean Won in millions): Related party A title of account June 30, December 31, Associates Kumho Tire Co., Inc. Loans 257,856 170,917 Loss allowance (62,957 ) (156,712 ) Deposits due to customers 482 666 Other liabilities 489 50 Woori Service Networks Co., Ltd. Loans 22 45 Deposits due to customers 1,732 1,311 Other liabilities 339 357 Korea Credit Bureau Co., Ltd. Loans 4 6 Deposits due to customers 1,063 5,586 Other liabilities 6 54 Korea Finance Security Co., Ltd. Loans 42 56 Loss allowance (2 ) — Deposits due to customers 3,078 2,854 Other liabilities 4 7 Chin Hung International Inc. Loans 182 408 Loss allowance (24 ) (22 ) Deposits due to customers 61,551 46,220 Other liabilities 2,899 1,658 Poonglim Industrial Co., Ltd. (*1) Deposits due to customers — 4 STX Engine Co., Ltd. (*2) Loans — 106,176 Loss allowance — (88,734 ) Deposits due to customers — 18,092 Other liabilities — 29 STX Corporation Loans 73,519 47,711 Loss allowance (49,734 ) (31,210 ) Deposits due to customers 2,130 77,555 Other liabilities 131 80 Associates K BANK Co., Ltd. Loans 103 212 Well to Sea No.3 Private Equity Fund Loans 85,000 73,810 Loss allowance (85 ) (39 ) Deposits due to customers 3,213 61 Other liabilities 69 27 Related party A title of account June 30, December 31, Others (*3) Loans 260 499 Loss allowance (235) (471) Other assets 1 1 Deposits due to customers 6,369 2,906 Other liabilities 153 73 (*1) The Group did not have significant influence over the entity due to the fact that the entity was going through workout process under receivership, and thus the entity was excluded from the investment in associates (*2) The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018. (*3) Others include Saman Corporation, Kyesan Engineering Co., Ltd., Hyunwoo International Co., Ltd., DAEA SNC Co., Ltd. and others as of June 30, 2018 and December 31, 2017. (3) Gain or loss from transactions with related parties are as follows (Unit: Korean Won in millions): For the six months Related party A title of account 2018 2017 Corporation that has significant influence over the group KDIC (*1) Interest expenses — 15,331 Associates Kumho Tire Co., Inc. Interest income 1,098 1,501 Fees income — 6 Impairment losses due to credit loss (reversal of allowance for credit loss) (93,755) 1,042 Woori Blackstone Korea Opportunity Private Equity Fund No.1 (*2) Fees income — 29 Woori Service Networks Co., Ltd. Other income 15 15 Interest expenses 7 13 Fees expenses 270 335 Other expenses 231 249 Korea Credit Bureau Co., Ltd. Interest expenses 21 38 Fees expenses 1,038 1,023 Korea Finance Security Co., Ltd. Interest expenses 4 5 Impairment losses due to credit loss 2 — Fees expenses 71 — Chin Hung International Inc. Interest income — 53 Fees income — 1 Interest expenses 21 13 Impairment losses due to credit loss (reversal of allowance for credit loss) 2 (4,270) For the six months Related party A title of account 2018 2017 Associates STX Engine Co., Ltd (*3). Interest income 333 672 Fees income — 28 Interest expenses 86 72 Reversal of allowance for credit loss (88,734) (1,835) Samho International Co., Ltd. (*4) Interest income — 364 Fees income — 6 Interest expenses — 214 Reversal of allowance for credit loss — (116) STX Corporation Interest income — 219 Fees income — 58 Interest expenses 2 4 Impairment losses due to credit loss (reversal of allowance for credit loss) 18,524 (59,507) K BANK Co., Ltd. Fees income 514 396 Other income 5 1,051 Well to Sea No.3 Interest income 1,288 — Private Equity Fund (*5) Interest expenses 4 — Impairment losses due to credit loss 46 — Others (*6) Other income 6 — Interest expenses 22 5 Reversal of impairment losses due to credit loss (236) (10) (*1) As its ownership interest in the Group is lower than 20% as of December 31, 2017, it has been excluded from the corporation that have significant influence over the Group. (*2) Due to disposition previous year, the entity is not in scope for associate. (*3) The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018. (*4) The entity was sold after it was transferred to assets held for sale and was excluded from the investment in associates for the year ended December 31, 2017. (*5) Due to capital contribution for the year ended December 31, 2017, the entity has been included in the investment in associates. (*6) Others include the amount transacted with Saman Corporation, Kyesan Engineering Co., Ltd., Hyunwoo International Co., Ltd., DAEA SNC Co., Ltd. and others for the six months ended June 30, 2018 and 2017. (4) Major loan transactions with related parties for the six months ended June 30, 2018 and June 30, 2017 are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Related parties Beginning Loan Collection Others Ending Associates Kumho Tire Co., Inc. 57,470 — 7,057 — 50,413 Well to Sea No. 3 Private Equity Fund (*2) 73,810 11,190 — — 85,000 STX Engine Co., Ltd. (*3) 39,886 — 2,177 (37,709 ) — For the six months ended June 30, 2017 Related parties Beginning Loan Collection Others Ending Associates Kumho Tire Co., Inc. 50,413 — — — 50,413 STX Engine Co., Ltd. (*3) 44,797 — 7,088 — 37,709 (*1) Settlement payment caused in operation among the related parties were excluded, and in the case of a limited loan, it was presented as a net increase (decrease). (*2) The entity is in scope for the associates due to contribution as of the year ended December 31, 2017. (*3) The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018. (5) There are no major borrowing transactions with related parties for the six months ended June 30, 2018 and June 30, 2017. (6) Guarantees provided to the related parties are as follows (Unit: Korean Won in millions): June 30, December 31, Warranty Kumho Tire Co., Inc. 13,830 4,181 Import credit in foreign currencies and others 511 636 Loan commitment Korea Finance Security Co., Ltd. 218 204 Loan commitment Korea Credit Bureau Co., Ltd. 31 29 Loan commitment Woori Service Networks Co., Ltd. 178 155 Loan commitment Chin Hung International Inc. 32,117 31,891 Loan commitment STX Engine Co., Ltd. (*) — 68,858 Import credit in foreign currencies and others STX corporation 14,914 17,557 Import credit in foreign currencies and others 132 53 Loan commitment K BANK Co., Ltd. 101 — Loan commitment Well to Sea No. 3 Private Equity Fund 225,000 236,190 Loan commitment (*) The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018. For the guarantee provided to the related parties, the Group recognized provisions for guarantees amounting to 11,525 million Won and 71,459 million Won, as of June 30, 2018 and December 31, 2017, respectively. (7) Compensation for key management is as follows (Unit: Korean Won in millions): For the six months 2018 2017 Short term benefits 6,023 6,524 Severance payments 280 280 Total 6,303 6,804 Key management includes registered executives and non-registered

Business combination

Business combination	6 Months Ended
	Jun. 30, 2018
Disclosure of detailed information about business combination [Abstract]
Business Combination	45. BUSINESS COMBINATION The business combination occurred during the current period is as follows: (1) Acquisition of WB Finance Co., Ltd. In order to expand Cambodia’s retail business, the Group had acquired 100% ownership of Vision Fund Cambodia on June, 2018. And The Group changed its name to WB Finance Co., Ltd.. (2) Details of the accounting for the business combination are as follows (Unit: Korean Won in millions): June 30, 2018 Consideration transferred: Cash and cash equivalents 88,216 Identifiable assets and liabilities recognized: Cash and cash equivalents 16,657 Financial assets at FVTOCI 17 Loans and other financial assets at amortized cost 205,451 Premises and equipment 1,630 Intangible assets 763 Current tax assets 173 Deferred tax assets 1,381 Other assets 1,510 Total assets 227,582 Deposits due to customers 54,615 Borrowings 120,644 Other financial liabilities 6,149 Current tax liabilities 640 Other liabilities 4,724 Total liabilities 186,772 Identifiable net fair value 40,810 Goodwill(*) 47,406 (*) Identifying the intangible assets and measuring the fair value of identifiable assets acquired are incomplete as the acquisition date was June 21, 2018. The amount of Goodwill could change due to the result of the measurement of the identifiable assets and liabilities.

Establishment of a financial ho

Establishment of a financial holding company and plan of stock transfer	6 Months Ended
	Jun. 30, 2018
Disclosure of financial holding company and plan of stock transfer [Abstract]
Establishment of a Financial Holding Company and Plan of Stock Transfer	46. ESTABLISHMENT OF A FINANCIAL HODING COMPANY AND PLAN OF STOCK TRANSFER The Group’s board of directors held a meeting on June 19, 2018, approving the plan to transfer shares which was formulated to facilitate the establishment of a financial holding company by means of comprehensive share transfer. In relation to the establishment of the financial holding company, the Group is currently undertaking processes to obtain approval from the Financial Services Committee. The six companies that are subject to the share transfer plan include the Bank, Woori FIS Co., Ltd., Woori Finance Research Institute Co., Ltd., Woori Credit Information Co., Ltd., Woori Fund Service Co., Ltd., and Woori Private Equity Asset Management Co., Ltd. After the Group obtains approval from the Financial Services Committee, the Group is planning to establish the financial holding company during the first half of 2019 through processes such as annual shareholders’ meeting. Following the establishment of the financial holding company, the six companies mentioned above will become fully owned subsidiaries of the holding company. After the financial holding company is established, the shares of the Group will be delisted from the Korea Stock Exchange and New York Stock Exchange during the first half of the 2019, and the shares of the newly established financial holding company will be listed on both Korea Stock Exchange and New York Stock Exchange.

Basis of preparation and sign52

Basis of preparation and significant accounting policies (Policies)	6 Months Ended
	Jun. 30, 2018
Accounting policies [Abstract]
Basis of presentation	Basis of presentation The Group’s consolidated interim financial statements are prepared in accordance with International Financial Reporting Standards (“IFRS”) 34, Interim Financial Reporting Consolidated Financial Statements Unless stated below, the accounting policies applied in preparing the accompanying consolidated interim financial statements have been applied consistently with the annual consolidated financial statements as of and for the year ended December 31, 2017.
Adoption of IFRS 9 – Financial instruments (enacted)	Adoption of IFRS 9 – Financial instruments The Group applied for the first time as of January 1, 2018, the adoption to IFRS 9 and other standards related to IFRS 9, which introduces new rules: 1) classification and measurement of financial assets and financial liabilities, 2) impairment of financial assets, and 3) hedge accounting. The Group decided not to restate the prior period figures when applying the Standard for the first time, thus the comparative financial statements presented are not restated. The main contents of the new accounting standard and the effect on the financial statements of the Group are as follows: a) Classification and measurement of financial assets and financial liabilities All financial assets included in the scope of IFRS 9 are subsequently measured at amortized cost or fair value based on the business model for the management of financial assets and the nature of the contractual cash flows. Debt instruments that are held within a business model whose objective is to collect the contractual cash flows, and that have contractual cash flows that are solely payments of principal and interest on the principal outstanding are generally measured at amortized cost at the end of subsequent accounting periods (financial assets at amortized cost). Debt instruments that are held within a business model whose objective is achieved both by collecting contractual cash flows and selling financial assets, and that have contractual terms that give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding, are generally measured at fair value through other comprehensive income (financial assets at fair value through other comprehensive income (“FVTOCI”)). All other debt instruments and equity instruments are measured at their fair value at the end of subsequent accounting periods (financial assets at fair value through profit or loss (“FVTPL”)). Notwithstanding the foregoing, the Group may make the following irrevocable choice or designation at the time of initial recognition of financial assets. The Group may make an irrevocable election to present in other comprehensive income subsequent changes in the fair value of an investment in an equity instrument within the scope of this Standard that is neither held for trading nor contingent consideration recognized by an acquirer in a business combination to which IFRS 3(R) applies. At initial recognition, financial assets at amortized cost or FVTOCI may be irrevocably designated as financial assets at fair value through profit or loss mandatorily measured at fair value if doing so eliminate or significantly reduce a measurement or recognition inconsistency. As of the date of first adoption of IFRS 9, there are no debt instruments classified either as financial assets at amortized cost or FVTOCI that are designated as financial assets at fair value through profit or loss. When debt instruments measured at FVTOCI are removed, the cumulative gain or loss recognized in other comprehensive income is reclassified from equity to profit or loss as a reclassification adjustment. On the other hand, for equity instruments designated as financial assets at fair value through other comprehensive income, cumulative gains or losses previously recognized in other comprehensive income are not subsequently reclassified to profit or loss. Debt instruments measured subsequently at amortized cost or fair value through other comprehensive income are subject to impairment provisions. The classification and measurement of financial assets and financial liabilities in accordance with IFRS 9 and IAS 39 as of January 1, 2018 are as follows (Unit: Korean Won in millions): Account Classification Classification Classification Reclassificati- Remeasure- Classification Deposit Loans and receivables Loan and other financial assets at amortized cost 8,870,835 — — 8,870,835 Deposit Financial assets at FVTPL Financial assets at FVTPL 25,972 — — 25,972 Debt securities Financial assets at FVTPL Financial assets at FVTPL(*) 2,654,027 — — 2,654,027 Equity securities Financial assets at FVTPL Financial assets at FVTPL(*) 47,304 — — 47,304 Derivatives Financial assets at FVTPL Financial assets at FVTPL(*) 3,115,775 (2,137 ) — 3,113,638 Equity securities Available-for-sale Financial assets at FVTPL(*) 1,273,498 1,219 — 1,274,717 Equity securities Available-for-sale Financial assets at FVTOCI 850,207 — — 850,207 Debt securities Available-for-sale Financial assets at FVTPL 46,855 — — 46,855 Debt securities Available-for-sale Financial assets at FVTOCI 12,874,209 — — 12,874,209 Debt securities Available-for-sale Securities at amortized cost 308,181 — 14,119 322,300 Debt securities Held to maturity financial assets Securities at amortized cost 16,749,296 — — 16,749,296 Loans Loans and receivables Financial assets at FVTPL (*) 279,032 918 50 280,000 Loans Loans and receivables Loan and other financial assets at amortized cost 253,014,491 — — 253,014,491 Derivatives Derivatives Derivatives 59,272 — — 59,272 Other financial assets Loans and receivables Loan and other financial assets at amortized cost 6,772,088 — — 6,772,088 Total financial assets 306,941,042 — 14,169 306,955,211 (*) Under IAS 39, the embedded derivatives out of hybrid financial instruments are accounted for as derivatives assets or liabilities if the criteria for separation of the embedded derivative are met and the rest of host contracts in those instruments are recorded as available-for-sale Account Classification Classification Classification Reclassifica- Remeasure- Classification Deposit due to customers Financial liabilities at FVTPL Financial liabilities at FVTPL 25,964 — — 25,964 Deposit due to customers Deposit due to customers Financial liabilities at amortized cost 234,695,084 — — 234,695,084 Borrowings Borrowings Financial liabilities at amortized cost 14,784,706 — — 14,784,706 Debentures Financial liabilities at FVTPL Financial liabilities at FVTPL 91,739 — — 91,739 Debentures Debentures Financial liabilities at amortized cost 27,869,651 — — 27,869,651 Equity-linked securities Financial liabilities at FVTPL Financial liabilities at FVTPL 160,057 — — 160,057 Derivatives liabilities Financial liabilities at FVTPL Financial liabilities at FVTPL 3,150,149 — — 3,150,149 Derivatives liabilities Derivatives liabilities Derivatives liabilities 67,754 — — 67,754 Other financial liabilities Other financial liabilities Financial liabilities at amortized cost 13,892,461 — — 13,892,461 Provision for financial guarantee Provision for financial guarantee Financial liabilities at amortized cost 71,697 — — 71,697 Total financial liabilities 294,809,262 — — 294,809,262 At the date of the initial application of IFRS 9, there were no financial assets or liabilities measured at FVTPL that were reclassified to FVTOCI or amortized cost category. As of the date of first adoption of IFRS 9, the amount of valuation gain or loss and the fair value of financial assets that would have been recognized in the book, had the entity decided not to reclassify financial assets at FVTPL or FVTOCI that has been reclassified into financial assets at amortized cost, are as follows: (Unit: Korean Won in millions) Account subject Category before the adoption of Amount of valuation gain/loss had Fair value Debt securities AFS securities (236 ) 302,638 b) Impairment of financial assets The impairment model under IFRS 9 reflects expected credit losses, as opposed to incurred credit losses under IAS 39. Under the impairment approach in IFRS 9, it is no longer necessary for a credit event to have occurred before credit losses are recognized. Instead, the Group accounts for expected credit losses and changes in those expected credit losses. The amount of expected credit losses should be updated at each reporting date to reflect changes in credit risk since initial recognition. The Group is required to recognize the expected credit losses for financial instruments measured at amortized cost or FVTOCI, and loan commitments and financial guarantee contracts that are subject to the impairment provisions of IFRS 9. In particular, when the credit risk of the financial instruments are significantly increased after initial recognition, or when the credit quality of the financial instruments are already impaired at acquisition, the loss allowance is measured as the expected credit loss for the whole life of the financial assets. If the credit risk of a financial instruments does not increase significantly after initial recognition (excluding POCI loans - for financial assets already impaired at initial recognition), the Group measures the loss allowance on the financial instruments at the amount equivalent to the expected 12-month Management determined the credit risk at the date of initial recognition of the financial instrument in accordance with IFRS 9 and provided a reasonable and supportive measure that can be used without undue cost or effort in comparison with the credit risk of the initial application date (January 1, 2018) the Group used information that could be used to assess the impairment of the Group’s financial assets, lending arrangements and financial guarantees at the date of initial application. As of January 1, 2018, the evaluation results are as follows (Unit: Korean Won in millions): Account Classification Classification Loss allowance Loss allowance Increases (B-A) Deposit Loans and receivables Loans and other financial assets at amortized cost 2,458 3,092 634 Debt securities AFS debt securities AFS financial assets Financial assets at FVTOCI — 4,236 4,236 HTM securities HTM financial assets Securities at amortized cost — 5,078 5,078 Loans and other financial assets Loans and receivables Loans and other financial assets at amortized cost 1,827,785 2,076,873 249,088 Payment guarantee 183,247 192,924 9,677 Loan commitment 66,115 104,985 38,870 Total 2,079,605 2,387,188 307,583 c) Classification and measurement of financial liabilities One of the major changes related to the classification and measurement of financial liabilities as a result of the adoption of IFRS 9 is the change in the fair value of financial liabilities designated at fair value through profit or loss due to the changes in issuer’s own credit risk. The Group recognizes the effect of changes in the credit risk of financial liabilities designated as at FVTOCI in other comprehensive income, except for cases where it causes or disproves accounting mismatch of the profit or loss. Changes in fair value due to credit risk of financial liabilities are not subsequently reclassified to profit or loss, but are reclassified as retained earnings when financial liabilities are eliminated. In accordance with IAS 39, the entire of changes in fair value of financial liabilities designated as at FVTPL are recognized in profit or loss. As of January 1, 2018, the Group designated 251,796 million Korean Won of FVTPL out of 294,813,795 million of financial liabilities, and recognized 133 million Korean Won as accumulated other comprehensive loss in relation to the changes in credit risk of financial liabilities. d) Hedge accounting The new hedge accounting model maintains three types of hedge accounting. However, it is introduced more flexibility in the types of transactions that are eligible for hedge accounting and is expanded the types of hedging instruments and non-financial In accordance with the transitional provisions of IFRS 9 on hedge accounting, the Group adopted the hedge accounting provisions of IFRS 9 prospectively from January 1, 2018. As of the date of initial application, the Group has considered that the hedging relationship in accordance with IAS 39 is appropriate for hedge accounting under IFRS 9, thus the hedging relationship is considered to exist continually. Since the major conditions for hedging instruments and the hedged items are consistent, all hedging relationships are consistent with the effectiveness assessment requirements of IFRS 9. The Group has not designated a hedging relationship in accordance with IFRS 9 in which the hedge relationship would not have met the requirements for hedge accounting under IAS 39. Consistent with prior periods, the Group continues to designate fair value changes in interest rate swaps as hedging instruments in the fair value hedge relationship. e) Effect on equity as a result of adoption of IFRS 9 The effect on equity due to the adoption of IFRS 9 as of January 1, 2018 is as follows (Unit: Korean Won in millions): - Impact on accumulated other comprehensive loss as result of financial assets at FVTOCI, etc. Amount Beginning balance (prior to IFRS 9) (89,723 ) Reclassification (392,177 ) Reclassification of available-for-sale 494 Reclassification of available-for-sale (152,124 ) Recognition of expected credit losses of debt securities at FVTOCI 4,293 Reclassified of available for sale financial assets (equity securities) to financial assets at FVTOCI (397,508 ) Effect on changes in credit risk of financial liabilities at fair value through profit or loss designated as upon initial recognition (133 ) Others 3,005 Income tax effect 149,796 Ending balance (based on IFRS 9) (481,900 ) - Retained earnings impact Amount Beginning balance (prior to IFRS 9) 15,620,006 Reclassification 177,091 Reclassification of available-for-sale (494 ) Reclassification of available-for-sale 152,067 Recognition of expected credit losses of debt instruments at FVTOCI (4,236 ) Reclassified of available for sale financial assets (equity securities) to financial assets at FVTOCI 397,508 Effect on revaluation of financial assets at amortized cost from loan and receivables or AFS financial assets 282 Recognition of expected credit losses of financial assets at amortized cost which were previously loan and receivables (240,683 ) Effect of payment guarantees / unused commitments on liabilities (48,548 ) Effect on changes in credit risk of financial liabilities at fair value through profit or loss designated as upon initial recognition 133 Others (4,456 ) Income tax effect (74,482 ) Ending balance (based on IFRS 9) 15,797,097
Adoption of IFRS 15 – Revenue from contracts with customers (enacted)	- Adoption of IFRS 15 – Revenue from contracts with customers (enacted) The Group adopted IFRS 15 for the first time and decided to retrospectively apply the cumulative effect of the first application of IFRS 15 as of January 1, 2018. In addition, the Standard has been retrospectively applied only to contracts that are not completed on the date of initial application, and all contractual changes made prior to the first application date are not rewritten. In addition, the Group decided not to restate the prior periods when applying IFRS 15 for the first time. Accordingly, the Group has not retroactively restated the comparative consolidated financial statements presented herein.
Amendments to IFRS 2 – Classification and Measurement of Share-based Payment Transactions	- Amendments to IFRS 2 – Classification and Measurement of Share-based Payment Transactions The amendments clarify the following; i) In estimating the fair value of a cash-settled share-based payment, the accounting for the effects of vesting and non-vesting
Amendments to IAS 40 – Transfers of Investment Property	- Amendments to IAS 40 – Transfers of Investment Property The amendments clarify that a transfer to, or from, investment property necessitates an assessment of whether a property meets the definition of investment property, supported by observable evidence that a change in use has occurred. The amendments further clarify that the situations listed in IAS 40 are not exhaustive and that a change in use is possible for properties under construction (i.e. a change in use is not limited to completed properties).
Amendments to IFRIC 22 – Foreign Currency Transactions and Advance Consideration	- Amendments to IFRIC 22 – Foreign Currency Transactions and Advance Consideration IFRIC 22 addresses how to determine the ‘date of transaction’ for the purpose of determining the exchange rate to use on initial recognition of an asset, expense or income (or part of them), when consideration for that item has been paid or received in advance in a foreign currency which resulted in the recognition of a non-monetary non-monetary non-refundable The Interpretation specifies that the date of transaction is the date on which the entity initially recognizes the non-monetary non-monetary
Annual Improvements to IFRS 2014-2016 Cycle	- Annual Improvements to IFRS 2014-2016 Cycle The amendments include partial amendments to IFRS 1 ‘First-time Adoption of IFRS’ and IAS 28 ‘Investments in Associates and Joint Ventures.’ Amendments to IAS 28 provide that an investment company such as a venture capital investment vehicle may selectively designate each of its investment in associates and/or joint ventures to be measured at fair value through profit or loss mandatorily measured at fair value, and that such designation must be made at the time of each investment’s initial recognition. In addition, when non-investment
IFRS 16—Leases (enacted)	- IFRS 16—Leases (enacted) IFRS 16 introduces a comprehensive model for the identification of lease arrangements and accounting treatments for both lessors and lessees. IFRS 16 will supersede the current lease guidance including IAS 17 Leases and the related interpretations, and will be applied to periods beginning on or after January 1, 2019. IFRS 16 distinguishes leases and service contracts on the basis of whether an identified asset is controlled by a customer. Distinctions of operating leases and finance leases are removed for lessee accounting, and is replaced by model where a right-of-use The right-of-use In contrast to lessee accounting, IFRS 16 substantially carries forward the lessor accounting requirements in IAS 17, and continues to require a lessor to classify a lease either as an operating lease or a finance lease. Also, IFRS 16 requires expanded disclosures. According to the preliminary assessment of the Group, the lease agreements entered into by the Group as of June 30, 2018 are expected to meet the definition of lease under the Standard, and accordingly, if the Group adopts the Standard, it applies to all leases except short-term leases and leases of low value assets, and the Group will recognize the right-of-use

Significant accounting estima53

Significant accounting estimates and assumptions (Policies)	6 Months Ended
	Jun. 30, 2018
Disclosure of accounting judgements and estimates explanatory [Abstract]
Significant accounting estimates and assumptions for preparation of the Interim financial statements	In the application of the Group’s accounting policies to the interim financial statements, management is required to make judgments, estimates and assumptions about the carrying amounts of assets and liabilities that are not readily apparent from other sources. Actual results can differ from those estimates based on such definitions. The significant judgments which management has made about the application of the Group’s accounting policies and key sources of uncertainty in estimate do not differ from those used in preparing the consolidated financial statements for the year ended December 31, 2017, except the Group’s policy, accounting estimates and assumptions described below;
Accounting policy for income tax	(1) Income taxes The Group is operating in numerous countries and the income generated from these operations is subject to income taxes based on tax laws and interpretations of tax authorities in numerous jurisdictions. There are many transactions and calculations which makes the ultimate tax determination uncertain. If certain portion of the taxable income is not used for investments, increase in wages, and others in accordance with the Tax System for Promotion of investment and Collaborative Cooperation (Recirculation of Corporate Income), the Group is liable to pay additional income tax calculated based on the tax laws. The new tax system is effective for three years from 2018. Accordingly, the measurement of current and deferred income tax is affected by the tax effects from the new system. As the Group’s income tax is dependent on the investments, increase in wages, and others, there exists uncertainty with regard to measuring the final tax effects.
Accounting policy for credit losses (allowance for loan losses, provisions for acceptances and guarantees, and unused loan commitments)	(2) Provisions for credit losses (allowances for loan losses, provisions for acceptances and guarantees, and unused loan commitments) In accordance with IFRS 9, the Group tests impairment and recognizes allowances for losses on financial assets classified at amortized cost, and debt instruments measured at fair value through other comprehensive income and lease receivables through impairment testing and recognizes provisions for guarantees, and unused loan commitments. Accuracy of provisions for credit losses is dependent upon estimation of expected cash flows of the borrower for individually assessed allowances of loans, and upon assumptions and methodology used for collectively assessed allowances for the Group’s of loans, guarantees and unused loan commitments.

General (Tables)

General (Tables)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Disclosure of investments in subsidiaries	(2) The consolidated financial statements for Woori Bank and its subsidiaries (the “Group”) include the following subsidiaries: Percentage of ownership Location Financial Subsidiaries Main business June 30, December 31, Woori Bank: Woori FIS Co., Ltd. System software 100.0 100.0 Korea June 30 Woori Private Equity Asset Management Co., Ltd. Finance 100.0 100.0 Korea June 30 Woori Finance Research Institute Co., Ltd. Other service 100.0 100.0 Korea June 30 Woori Card Co., Ltd. Finance 100.0 100.0 Korea June 30 Woori Investment Bank Co., Ltd. Other credit 59.8 59.8 Korea June 30 Woori Credit Information Co., Ltd. Credit information 100.0 100.0 Korea June 30 Woori America Bank Finance 100.0 100.0 U.S.A. June 30 Woori Global Markets Asia Limited ” 100.0 100.0 Hong Kong June 30 Woori Bank China Limited ” 100.0 100.0 China June 30 AO Woori Bank ” 100.0 100.0 Russia June 30 PT Bank Woori Saudara Indonesia 1906 Tbk ” 79.9 79.9 Indonesia June 30 Banco Woori Bank do Brasil S.A. ” 100.0 100.0 Brazil June 30 Korea BTL Infrastructure Fund ” 99.9 99.9 Korea June 30 Woori Fund Service Co., Ltd. ” 100.0 100.0 Korea June 30 Woori Finance Cambodia PLC. ” 100.0 100.0 Cambodia June 30 Woori Finance Myanmar Co., Ltd. ” 100.0 100.0 Myanmar June 30 Wealth Development Bank ” 51.0 51.0 Philippines June 30 Woori Bank Vietnam Limited ” 100.0 100.0 Vietnam June 30 WB Finance Co., Ltd. ” 100.0 — Cambodia June 30 Kumho Trust First Co., Ltd. (*1) Asset securitization 0.0 0.0 Korea June 30 Asiana Saigon Inc. (*1) ” 0.0 0.0 Korea June 30 Consus Eighth Co., LLC (*1) ” 0.0 0.0 Korea June 30 KAMCO Value Recreation First Securitization Specialty Co., Ltd. (*1) ” 15.0 15.0 Korea June 30 Hermes STX Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 BWL First Co., LLC (*1) ” 0.0 0.0 Korea June 30 Deogi Dream Fourth Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Jeonju Iwon Ltd. (*1) ” 0.0 0.0 Korea June 30 Wonju I one Inc. (*1) ” 0.0 0.0 Korea June 30 Heitz Third Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Woorihansoop 1st Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Electric Cable First Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Woori International First Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Woori HJ First Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Woori WEBST 1st Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Wibihansoop 1st Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 HNLD 1st Inc.(*4) ” — 0.0 Korea — Percentage of ownership Location Financial Subsidiaries Main business June 30, December 31, Uri QS 1st Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Uri Display 1st Co., Ltd.(*1) ” 0.0 0.0 Korea June 30 Tiger Eyes 2nd Co., Ltd.(*1) ” 0.0 0.0 Korea June 30 Woori Serveone 1st Co., Ltd. (*1) ” 0.0 0.0 Korea June 30 Uri Display 2nd Co.,Ltd. (*1) ” 0.0 — Korea June 30 Woori the Colony Unjung Securitization Specialty Co., Ltd. (*1) ” 0.0 — Korea June 30 Woori Dream 1st Co., Ltd. (*1) ” 0.0 — Korea June 30 Woori HS 1st Co., Ltd. (*1) ” 0.0 — Korea June 30 Smart Casting Inc. (*1) ” 0.0 — Korea June 30 HeungkukWoori Tech Company Private Placement Investment Trust No. 1 and 6 beneficiary certificates (*2) Securities investment — — Korea June 30 Principle Guaranteed Trust (*3) Trust 0.0 0.0 Korea June 30 Principle and Interest Guaranteed Trust (*3) ” 0.0 0.0 Korea June 30 Woori Investment Bank: Dongwoo First Securitization Specialty Co., Ltd. (*1) Asset securitization 5.0 5.0 Korea June 30 Seari First Securitization Specialty Co., Ltd. (*1) ” 5.0 5.0 Korea June 30 Namjong 1st Securitization Specialty Co., Ltd. (*1) ” 5.0 5.0 Korea June 30 Bukgeum First Securitization Specialty Co., Ltd. (*1) ” 5.0 5.0 Korea June 30 Seori Second Securitization Specialty Co., Ltd. (*1) Asset securitization 5.0 — Korea June 30 Bukgeum Second Securitization Specialty Co., Ltd. (*1) ” 5.0 — Korea June 30 Woori Card Co., Ltd.: TUTU Finance-WCI Finance 100.0 100.0 Myanmar June 30 Woori Card one of 2017-1 Asset securitization 0.5 0.5 Korea June 30 Woori Card one of 2017-2 ” 0.5 0.5 Korea June 30 (*1) The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns. (*2) The entity was a structured entity for the purpose of investment in securities and was in scope for consolidation, considering that the Group 1) had the power over the investee, 2) was exposed, or has rights, to variable returns from its involvement with the investee, and 3) has the ability to use its power to affect its returns. (*3) The entity was a money trust under the Financial Investment Services and Capital Markets Act and was in scope for consolidation. Although the Group was not a majority shareholder, the Group 1) has the power over the investee, 2) was exposed, or has rights, to variable returns from its involvement with the investee, and 3) has the ability to use its power to affect its returns. (*4) The entity is a structured entity for the purpose of asset securitization and is not in scope for consolidation considering that the Group 1) does not have the power over the investee, 2) is not exposed, or does not have rights to variable returns from its involvement with the investee, and 3) does not have the ability to use its power to affect its returns.
Unconsolidated companies with more than 50 Percent ownership interests	(3) As of June 30, 2018, and December 31, 2017, despite having more than 50% ownership interest, the Group has not consolidated the following companies as the Group does not have the ability to control following subsidiaries: As of June 30, 2018 Subsidiaries Location Main Percentage of Golden Bridge NHN Online Private Equity Investment (*) Korea Securities Investment 60.0 Mirae Asset Maps Clean Water Private Equity Investment Trust 7th (*) Korea Securities Investment 57.1 Kiwoom Yonsei Private Equity Investment Trust (*) Korea Securities Investment 88.3 Hana Walmart Real Estate Investment Trust 41-1 Korea Securities Investment 77.0 IGIS Global Private Placement Real Estate Fund No. 148-1 (*) Korea Securities Investment 75.0 IGIS Global Private Placement Real Estate Fund No. 148-2 (*) Korea Securities Investment 75.0 Mirae Asset Seoul Ring Expressway Private Special Asset Fund I (*) Korea Securities Investment 66.2 Hangkang Sewage Treatment Plant Fund (*) Korea Securities Investment 55.6 Consus KyungJu Green Private Placement Real Estate Fund 1 st Korea Securities Investment 52.4 (*) The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities. As of December 31, 2017 Subsidiaries Location Main Percentage of Golden Bridge NHN Online Private Equity Investment (*) Korea Securities Investment 60.0 Mirae Asset Maps Clean Water Private Equity Investment Trust 7th (*) Korea Securities Investment 59.7 Kiwoom Yonsei Private Equity Investment Trust (*) Korea Securities Investment 88.9 Hana Walmart Real Estate Investment Trust 41-1 Korea Securities Investment 90.1 IGIS Global Private Placement Real Estate Fund No. 148-1 (*) Korea Securities Investment 75.0 IGIS Global Private Placement Real Estate Fund No. 148-2 (*) Korea Securities Investment 75.0 (*) The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.
Summarized financial information before elimination of intercompany transactions of the subsidiaries	(4) The summarized financial information before the elimination of intercompany transactions of the subsidiaries whose financial information was prepared under IFRS for the Group’s consolidated financial statements is as follows (Unit: Korean Won in millions): As of and for the six months ended June 30, 2018 Assets Liabilities Operating Net income Comprehensive Woori FIS Co., Ltd. 80,851 55,312 138,088 (7,006 ) (7,040 ) Woori Private Equity Asset Management Co., Ltd. 40,799 2,064 556 (1,493 ) (1,490 ) Woori Finance Research Institute Co., Ltd. 4,314 615 2,776 258 258 Woori Card Co., Ltd. 9,100,890 7,462,577 944,657 67,618 62,866 Woori Investment Bank Co., Ltd. 2,723,251 2,418,664 109,428 14,722 14,878 Woori Credit Information Co., Ltd. 34,130 6,167 17,601 839 839 Woori America Bank 2,073,420 1,777,327 42,624 11,186 24,091 Woori Global Markets Asia Limited 406,684 287,622 7,302 2,156 7,298 Woori Bank China Limited 5,120,070 4,596,883 143,390 7,382 25,267 AO Woori Bank 277,555 224,860 8,778 2,570 200 PT Bank Woori Saudara Indonesia 1906 Tbk 2,349,222 1,858,176 96,177 22,401 15,947 Banco Woori Bank do Brasil S.A. 155,083 125,288 7,341 882 (2,515 ) Korea BTL Infrastructure Fund 777,576 297 14,704 12,865 12,865 Woori Fund Service Co., Ltd. 13,411 977 4,922 1,023 1,023 Woori Finance Cambodia PLC. 73,212 52,584 4,912 1,277 2,197 Woori Finance Myanmar Co., Ltd. 19,837 6,496 2,086 (187 ) 412 Wealth Development Bank 185,866 152,414 6,240 (2 ) (788 ) Woori Bank Vietnam Limited 1,142,018 990,228 23,746 3,545 8,822 WB Finance Co., Ltd. 227,582 186,772 — — — Money trust under the FISCM Act (*) 1,573,367 1,543,491 24,029 (36 ) (36 ) Structured entity for the securitization of financial assets 1,226,022 1,631,837 32,089 12,202 5,725 Structured entity for the investments in securities 41,221 40 785 (798 ) (1,869 ) (*) FISCM Act: Financial Investment Services and Capital Markets Act As of and for the year ended December 31, 2017 Assets Liabilities Operating Net income Comprehensive Woori FIS Co., Ltd. 103,932 71,386 252,460 1,940 (2,963 ) Woori Private Equity Asset Management Co., Ltd. 42,894 2,670 7,257 (4,114 ) (4,074 ) Woori Finance Research Institute Co., Ltd. 3,790 350 4,733 83 64 Woori Card Co., Ltd. 8,605,993 6,973,705 1,771,157 101,214 107,321 Woori Investment Bank Co., Ltd. 1,880,157 1,588,610 183,376 20,023 20,210 Woori Credit Information Co., Ltd. 33,298 6,175 31,580 861 752 Woori America Bank 1,954,301 1,679,248 81,337 11,869 (16,833 ) Woori Global Markets Asia Limited 290,226 178,343 11,345 1,922 (12,544 ) Woori Bank China Limited 4,960,637 4,458,683 388,913 13,809 (15,252 ) AO Woori Bank 201,704 149,101 15,656 4,748 1,217 As of and for the year ended December 31, 2017 Assets Liabilities Operating Net income Comprehensive PT Bank Woori Saudara Indonesia 1906 Tbk 2,230,617 1,745,171 192,485 38,488 (18,689 ) Banco Woori Bank do Brasil S.A. 213,889 181,544 20,455 1,843 (2,840 ) Korea BTL Infrastructure Fund 786,480 301 30,240 26,390 26,390 Woori Fund Service Co., Ltd. 12,653 1,242 9,021 1,398 1,398 Woori Finance Cambodia PLC. 51,304 32,873 5,895 983 (473 ) Woori Finance Myanmar Co., Ltd. 18,236 5,307 2,506 791 15 Wealth Development Bank 191,049 156,808 13,632 1,323 (1,093 ) Woori Bank Vietnam Limited 775,758 632,160 29,698 2,436 (15,347 ) Money trust under the FISCM Act (*) 1,560,672 1,530,760 44,344 582 582 Structured entity for the securitization of financial assets 867,583 1,275,719 22,730 1,179 (2,800 ) Structured entity for the investments in securities 34,939 76 377 (475 ) (38,592 ) (*) FISCM Act: Financial Investment Services and Capital Markets Act
Total assets of the unconsolidated structured entities the carrying value of the related items recorded the maximum exposure to risks and the loss recognized	Total assets of the unconsolidated structured entities, the carrying value of the related items recorded, the maximum exposure to risks, and the loss recognized in conjunction with the unconsolidated structured entities as of June 30, 2018 and December 31, 2017 are as follows (Unit: Korean Won in millions): June 30, 2018 Asset Structured Investment Total asset of the unconsolidated structured entities 7,955,990 36,949,944 14,777,372 Assets recognized in the consolidated financial statements related to the unconsolidated structured entities 2,956,395 2,162,493 1,333,612 Financial assets at FVTPL 232,931 69,259 1,079,544 Financial assets at FVTOCI 499,861 49,538 — Financial assets at amortized cost 2,223,211 2,039,184 10,697 Investments in joint ventures and associates — 885 243,371 Derivative assets 392 3,627 — Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities 1,442 1,587 81 Derivative liabilities 361 749 — Other liabilities (including provisions) 1,081 838 81 The maximum exposure to risks 3,697,522 2,818,678 1,398,067 Investments 2,956,395 2,162,493 1,333,612 Credit facilities 741,127 656,185 64,455 Loss recognized on unconsolidated structured entities 158 8,757 9,110 F-15 December 31, 2017 Asset Structured Investment Total asset of the unconsolidated structured entities 7,295,601 40,172,830 13,641,135 Assets recognized in the consolidated financial statements related to the unconsolidated structured entities 3,215,159 2,314,043 1,138,523 Loans and receivables 43,180 1,969,760 — Financial assets held for trading — 233,428 10,160 AFS financial assets 902,390 106,819 904,774 HTM financial assets 2,269,451 — — Investments in joint ventures and associates — — 223,589 Derivative assets 138 4,036 — Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities 1,433 1,506 — Derivative liabilities 575 968 — Other liabilities (including provisions) 858 538 — The maximum exposure to risks 4,032,531 2,918,448 1,138,523 Investments 3,215,159 2,314,043 1,138,523 Credit facilities 817,372 604,405 — Loss recognized on unconsolidated structured entities 837 3,939 5,993
Accumulated non-controlling interests	(7) Subsidiaries of which non-controlling 1) Accumulated non-controlling June 30, 2018 December 31, 2017 Woori Investment Bank 125,809 119,111 PT Bank Woori Saudara Indonesia 1906 Tbk 66,004 64,877 Wealth Development Bank 16,391 16,778 2) Net income attributable to non-controlling For the six months ended For the six months ended Woori Investment Bank 5,912 5,072 PT Bank Woori Saudara Indonesia 1906 Tbk 4,508 5,048 Wealth Development Bank (1 ) 515 3) Dividends to non-controlling For the six months ended For the six months ended PT Bank Woori Saudara Indonesia 1906 Tbk 2,082 1,513

Basis of preparation and sign55

Basis of preparation and significant accounting policies (Tables)	6 Months Ended
	Jun. 30, 2018
Accounting policies [Abstract]
Classification and measurement	The classification and measurement of financial assets and financial liabilities in accordance with IFRS 9 and IAS 39 as of January 1, 2018 are as follows (Unit: Korean Won in millions): Account Classification Classification Classification Reclassificati- Remeasure- Classification Deposit Loans and receivables Loan and other financial assets at amortized cost 8,870,835 — — 8,870,835 Deposit Financial assets at FVTPL Financial assets at FVTPL 25,972 — — 25,972 Debt securities Financial assets at FVTPL Financial assets at FVTPL(*) 2,654,027 — — 2,654,027 Equity securities Financial assets at FVTPL Financial assets at FVTPL(*) 47,304 — — 47,304 Derivatives Financial assets at FVTPL Financial assets at FVTPL(*) 3,115,775 (2,137 ) — 3,113,638 Equity securities Available-for-sale Financial assets at FVTPL(*) 1,273,498 1,219 — 1,274,717 Equity securities Available-for-sale Financial assets at FVTOCI 850,207 — — 850,207 Debt securities Available-for-sale Financial assets at FVTPL 46,855 — — 46,855 Debt securities Available-for-sale Financial assets at FVTOCI 12,874,209 — — 12,874,209 Debt securities Available-for-sale Securities at amortized cost 308,181 — 14,119 322,300 Debt securities Held to maturity financial assets Securities at amortized cost 16,749,296 — — 16,749,296 Loans Loans and receivables Financial assets at FVTPL (*) 279,032 918 50 280,000 Loans Loans and receivables Loan and other financial assets at amortized cost 253,014,491 — — 253,014,491 Derivatives Derivatives Derivatives 59,272 — — 59,272 Other financial assets Loans and receivables Loan and other financial assets at amortized cost 6,772,088 — — 6,772,088 Total financial assets 306,941,042 — 14,169 306,955,211 (*) Under IAS 39, the embedded derivatives out of hybrid financial instruments are accounted for as derivatives assets or liabilities if the criteria for separation of the embedded derivative are met and the rest of host contracts in those instruments are recorded as available-for-sale Account Classification Classification Classification Reclassifica- Remeasure- Classification Deposit due to customers Financial liabilities at FVTPL Financial liabilities at FVTPL 25,964 — — 25,964 Deposit due to customers Deposit due to customers Financial liabilities at amortized cost 234,695,084 — — 234,695,084 Borrowings Borrowings Financial liabilities at amortized cost 14,784,706 — — 14,784,706 Debentures Financial liabilities at FVTPL Financial liabilities at FVTPL 91,739 — — 91,739 Debentures Debentures Financial liabilities at amortized cost 27,869,651 — — 27,869,651 Equity-linked securities Financial liabilities at FVTPL Financial liabilities at FVTPL 160,057 — — 160,057 Derivatives liabilities Financial liabilities at FVTPL Financial liabilities at FVTPL 3,150,149 — — 3,150,149 Derivatives liabilities Derivatives liabilities Derivatives liabilities 67,754 — — 67,754 Other financial liabilities Other financial liabilities Financial liabilities at amortized cost 13,892,461 — — 13,892,461 Provision for financial guarantee Provision for financial guarantee Financial liabilities at amortized cost 71,697 — — 71,697 Total financial liabilities 294,809,262 — — 294,809,262
Fair value and fair value gain or loss of financial assets reclassified as measured at amortized cost at first application of IFRS 9	As of the date of first adoption of IFRS 9, the amount of valuation gain or loss and the fair value of financial assets that would have been recognized in the book, had the entity decided not to reclassify financial assets at FVTPL or FVTOCI that has been reclassified into financial assets at amortized cost, are as follows: (Unit: Korean Won in millions) Account subject Category before the adoption of Amount of valuation gain/loss had Fair value Debt securities AFS securities (236 ) 302,638
Impairment of financial assets	Management determined the credit risk at the date of initial recognition of the financial instrument in accordance with IFRS 9 and provided a reasonable and supportive measure that can be used without undue cost or effort in comparison with the credit risk of the initial application date (January 1, 2018) the Group used information that could be used to assess the impairment of the Group’s financial assets, lending arrangements and financial guarantees at the date of initial application. As of January 1, 2018, the evaluation results are as follows (Unit: Korean Won in millions): Account Classification Classification Loss allowance Loss allowance Increases (B-A) Deposit Loans and receivables Loans and other financial assets at amortized cost 2,458 3,092 634 Debt securities AFS debt securities AFS financial assets Financial assets at FVTOCI — 4,236 4,236 HTM securities HTM financial assets Securities at amortized cost — 5,078 5,078 Loans and other financial assets Loans and receivables Loans and other financial assets at amortized cost 1,827,785 2,076,873 249,088 Payment guarantee 183,247 192,924 9,677 Loan commitment 66,115 104,985 38,870 Total 2,079,605 2,387,188 307,583
Effect on accumulated other comprehensive income or loss out of equity as a result of adoption of IFRS 9	- Impact on accumulated other comprehensive loss as result of financial assets at FVTOCI, etc. Amount Beginning balance (prior to IFRS 9) (89,723 ) Reclassification (392,177 ) Reclassification of available-for-sale 494 Reclassification of available-for-sale (152,124 ) Recognition of expected credit losses of debt securities at FVTOCI 4,293 Reclassified of available for sale financial assets (equity securities) to financial assets at FVTOCI (397,508 ) Effect on changes in credit risk of financial liabilities at fair value through profit or loss designated as upon initial recognition (133 ) Others 3,005 Income tax effect 149,796 Ending balance (based on IFRS 9) (481,900 )
Effect on retained earnings out of equity as a result of adoption of IFRS 9	- Retained earnings impact Amount Beginning balance (prior to IFRS 9) 15,620,006 Reclassification 177,091 Reclassification of available-for-sale (494 ) Reclassification of available-for-sale 152,067 Recognition of expected credit losses of debt instruments at FVTOCI (4,236 ) Reclassified of available for sale financial assets (equity securities) to financial assets at FVTOCI 397,508 Effect on revaluation of financial assets at amortized cost from loan and receivables or AFS financial assets 282 Recognition of expected credit losses of financial assets at amortized cost which were previously loan and receivables (240,683 ) Effect of payment guarantees / unused commitments on liabilities (48,548 ) Effect on changes in credit risk of financial liabilities at fair value through profit or loss designated as upon initial recognition 133 Others (4,456 ) Income tax effect (74,482 ) Ending balance (based on IFRS 9) 15,797,097

Risk Management (Tables)

Risk Management (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of risk management [Abstract]
Maximum exposure to credit risk by customer	2) Maximum exposure to credit risk The Group’s maximum exposure to credit risk refers to net book value of financial assets net of allowances, which shows the uncertainties of maximum changes of net value of financial assets attributable to a particular risk without considering collateral and other credit enhancements obtained. However, the maximum exposure is the fair value amount (recorded on the books) for derivatives, maximum contractual obligation for payment guarantees and unused commitment. The maximum exposure to credit risk is as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Loans and other financial assets at amortized cost Korean treasury and government agencies 17,912,135 — Banks 21,942,788 — Corporates 92,333,155 — Consumers 145,531,925 — Subtotal 277,720,003 — Loans and receivables Korean treasury and government agencies — 8,823,584 Banks — 26,845,309 Corporates — 90,570,551 Consumers — 140,866,760 Subtotal — 267,106,204 Financial assets at FVTPL (IFRS 9) Deposit 24,921 — Debt securities 1,993,851 — Loans and receivables 336,967 — Derivative assets 2,391,211 — Subtotal 4,746,950 — Financial assets at FVTPL (IAS 39) Deposit — 25,972 Debt securities — 2,644,333 Financial assets designated at FVTPL — 9,694 Derivative assets — 3,115,775 Subtotal — 5,795,774 Financial assets at FVTOCI Debt securities 13,738,829 — AFS financial assets Debt securities — 13,229,244 Securities at amortized cost Debt securities 17,702,129 — HTM financial assets Debt securities — 16,749,296 Derivative assets Derivative assets (hedging) 12,395 59,272 Off-balance Guarantees 12,372,573 12,859,715 Loan commitments 98,251,006 80,760,325 Subtotal 110,623,579 93,620,040 total 424,543,885 396,559,830
Credit risk exposure by geographical areas	a) Credit risk exposure by geographical areas The following tables analyze credit risk exposure by geographical areas (Unit: Korean Won in millions): June 30, 2018 Korea China USA UK Japan Others (*) Total Loans and other financial assets at amortized cost 258,023,468 4,589,930 4,514,541 1,268,461 400,907 8,922,696 277,720,003 Securities at amortized cost 17,531,402 — 64,856 — — 105,871 17,702,129 Financial assets at FVTPL 4,493,256 6,077 — 147,242 — 100,375 4,746,950 Financial assets at FVTOCI 12,749,695 50,874 43,352 78,485 2,274 814,149 13,738,829 Derivative assets 7,450 — — 4,945 — — 12,395 Off-balance 108,052,029 928,841 175,050 70,503 31,216 1,365,940 110,623,579 Total 400,857,300 5,575,722 4,797,799 1,569,636 434,397 11,309,031 424,543,885 December 31, 2017 Korea China USA UK Japan Others (*) Total Loans and receivables 250,678,479 4,104,912 2,823,247 1,094,988 381,890 8,022,688 267,106,204 Financial assets at FVTPL 5,551,870 2,937 — 148,955 — 92,012 5,795,774 AFS debt securities 12,407,602 52,259 151,131 — — 618,252 13,229,244 HTM securities 16,606,692 — 63,732 — — 78,872 16,749,296 Derivative assets 16,590 — — 42,682 — — 59,272 Off-balance 91,603,852 529,193 172,570 66,974 25,039 1,222,412 93,620,040 Total 376,865,085 4,689,301 3,210,680 1,353,599 406,929 10,034,236 396,559,830 (*) Others consist of financial assets in Indonesia, Hong Kong, Singapore, and other countries.
Credit risk exposure by industries	b) Credit risk exposure by industries The following tables analyze credit risk exposure by industries, which are service, manufacturing, finance and insurance, construction, individuals and others in accordance with the Korea Standard Industrial Classification Code (Unit: Korean Won in millions): June 30, 2018 Service Manufacturing Finance and Construction Individuals Others Total Loans and other financial assets at amortized cost 48,025,922 35,583,702 42,207,115 3,657,220 138,906,711 9,339,333 277,720,003 Securities at amortized cost 1,142,178 — 11,516,407 313,936 — 4,729,608 17,702,129 Financial assets at FVTPL 97,529 166,054 3,404,674 43,899 3,019 1,031,775 4,746,950 Financial assets at FVTOCI 434,389 54,445 9,020,012 214,549 — 4,015,434 13,738,829 Derivative assets — — 12,395 — — — 12,395 Off-balance 18,236,857 22,675,034 9,503,718 4,052,757 49,105,163 7,050,050 110,623,579 Total 67,936,875 58,479,235 75,664,321 8,282,361 188,014,893 26,166,200 424,543,885 December 31, 2017 Service Manufacturing Finance and Construction Individuals Others Total Loans and receivables 47,192,641 34,502,509 38,260,051 3,574,746 133,094,287 10,481,970 267,106,204 Financial assets at FVTPL 100,766 83,239 4,640,068 15,073 1,040 955,588 5,795,774 AFS debt securities 707,737 37,719 7,331,774 153,534 — 4,998,480 13,229,244 HTM securities 1,348,754 — 10,962,149 296,214 — 4,142,179 16,749,296 Derivative assets — — 59,272 — — — 59,272 Off-balance 16,892,926 21,427,378 9,841,379 3,842,479 36,928,554 4,687,324 93,620,040 Total 66,242,824 56,050,845 71,094,693 7,882,046 170,023,881 25,265,541 396,559,830
Three stages of credit risk deterioration since initial recognition	3) Credit risk exposure The allowance to be recognized under IFRS 9 is the amount of expected 12-month Stage 1 Stage 2 Stage 3 Credit risk has not significantly Credit risk has Credit has been Allowance for expected credit losses Expected 12-month credit losses: Expected lifetime credit losses: Expected credit losses due to 12-month Expected credit losses from all possible defaults during the expected lifetime of the financial instruments. (*) Credit risk may be considered to not have been significantly increased when credit risk is low at the reporting date.
Determining significant increase in credit risk, and the applied methodology	At the end of each period the Group evaluates whether there has been a significant increase in the credit risk since initial recognition. The Group is assessing the change in the risk of a default occurring over the expected life of the financial instruments instead of the change in the amount of expected credit losses. The Group distinguishes corporates/consumers exposures when determining significant increase in credit risk, and the applied methodology is as follows: Corporates exposure Consumers exposure Under precautionary in assets quality More than 30 days past due Watch grade in early warning system Significant change of borrower financial situation (Working capital deficiencies, Adverse opinion, Disclaimer of opinion) Significant decreases in credit ratings Under precautionary in assets quality More than 30 days past due Significant decreases in credit ratings
The maximum exposure to credit risk of financial assets, except for financial assets at FVTPL and derivative asset	a) Financial assets The maximum exposure to credit risk, except for financial assets at FVTPL and derivative asset is as follows (Unit: Korean Won in millions): June 30, 2018 Stage 1 Stage 2 Stage 3 Total Loss Total, net Collateral Above Less than a Above Less than a Loans and other financial assets at amortized cost 246,719,865 18,794,529 6,195,331 5,772,369 2,068,664 279,550,758 (1,830,755 ) 277,720,003 789,660 Korean treasury and government agencies 17,916,231 — — — — 17,916,231 (4,096 ) 17,912,135 — Banks 21,599,560 83,471 269,742 — 10,905 21,963,678 (20,890 ) 21,942,788 — Corporates 72,113,414 15,745,380 582,857 3,618,576 1,482,948 93,543,175 (1,210,020 ) 92,333,155 555,228 General business 42,620,870 6,674,237 510,663 1,681,120 1,231,634 52,718,524 (843,365 ) 51,875,159 405,304 Small- and medium-sized 25,012,286 8,491,759 72,194 1,766,232 222,804 35,565,275 (327,323 ) 35,237,952 130,181 Project financing and others 4,480,258 579,384 — 171,224 28,510 5,259,376 (39,332 ) 5,220,044 19,743 June 30, 2018 Stage 1 Stage 2 Stage 3 Total Loss Total, net Collateral Above Less than a Above Less than a Consumers 135,090,660 2,965,678 5,342,732 2,153,793 574,811 146,127,674 (595,749 ) 145,531,925 234,432 Securities at amortized cost 17,707,379 — — — — 17,707,379 (5,250 ) 17,702,129 — Financial assets at FVTOCI (*3) 13,675,528 48,126 15,175 — — 13,738,829 (4,670 ) 13,738,829 — Total 278,102,772 18,842,655 6,210,506 5,772,369 2,068,664 310,996,966 (1,840,675 ) 309,160,961 789,660 (*1) Credit grade of corporates are AAA ~ BBB, and consumers are grades 1 ~ 6. (*2) Credit grade of corporates are BBB- (*3) Financial assets at FVTOCI have not been disclosed as the amount before deducting provisions because the carrying amount does not decrease.
The maximum exposure to credit risk of loans and receivables	- Loans and receivables December 31, 2017 Corporates Korean Banks General Small and Project Subtotal Consumers Total Loans and receivables neither overdue nor impaired 8,825,767 26,861,286 50,463,112 34,107,547 5,547,950 90,118,609 139,886,407 265,692,069 Loans and receivables overdue but not impaired 8 — 65,616 63,067 — 128,683 878,406 1,007,097 Impaired loans and receivables — — 1,402,131 251,431 46,717 1,700,279 537,001 2,237,280 Total 8,825,775 26,861,286 51,930,859 34,422,045 5,594,667 91,947,571 141,301,814 268,936,446 Allowance for credit losses 2,191 15,977 1,078,733 267,162 31,125 1,377,020 435,054 1,830,242 Total, net 8,823,584 26,845,309 50,852,126 34,154,883 5,563,542 90,570,551 140,866,760 267,106,204
Credit soundness of debt securities	- Debt securities The Group manages debt securities based on the external credit rating. Credit soundness of debt securities on the basis of External Credit Assessment Institution (ECAI)’s rating is as follows (Unit: Korean Won in millions): December 31, 2017 Financial assets at AFS debt HTM securities Total AAA 1,685,099 9,897,689 15,806,327 27,389,115 AA- 722,923 2,386,567 888,547 3,998,037 BBB- 236,311 876,482 52,188 1,164,981 Below BBB- 9,694 68,506 2,234 80,434 Total 2,654,027 13,229,244 16,749,296 32,632,567 (*) Financial assets at FVTPL comprise debt securities held for trading and financial assets designated at FVTPL
Credit quality of guarantees and loan commitments	b) Guarantees and loan commitments The credit quality of the guarantees and loan commitments as of June 30, 2018 as follows (Unit: Korean Won in millions): June 30, 2018 Financial assets Stage 1 Stage 2 Stage 3 Total Above Less than a Above Less than a Off-balance 10,684,154 1,104,097 12,464 390,253 181,605 12,372,573 Loan commitments 92,335,107 3,717,790 1,455,884 740,283 1,942 98,251,006 Total 103,019,261 4,821,887 1,468,348 1,130,536 183,547 110,623,579 (*1) Credit grade of corporates are AAA ~ BBB, and consumers are grades 1 ~ 6. (*2) Credit grade of corporate are BBB-
Value at risk analysis for trading activities	a) Trading activities The minimum, maximum and average VaR for the six months ended June 30, 2018 and for the year ended December 31, 2017, respectively, and the VaR as of June 30, 2018 and December 31, 2017, respectively, are as follows (Unit: Korean Won in millions): As of For the six months ended As of For the year ended Risk factor Average Maximum Minimum Average Maximum Minimum Interest rate 2,179 3,787 4,992 1,730 4,183 3,799 4,918 2,467 Stock price 2,872 2,524 4,618 1,138 909 2,863 4,419 909 Foreign currencies 4,224 4,853 6,136 3,695 4,750 5,051 6,636 4,061 Commodity price 2 1 4 — — 31 188 — Diversification (4,095 ) (4,745 ) (7,136 ) (1,749 ) (4,472 ) (4,621 ) (6,798 ) (2,067 ) Total VaR(*) 5,182 6,420 8,614 4,814 5,370 7,123 9,363 5,370 (*) VaR : Maximum losses
Net interest income and net portfolio value analysis according to interest changing scenario for assets and liabilities held by the bank	b) Non-trading The NII and NPV are calculated for the assets and liabilities owned by the Bank and consolidated trusts, respectively, by using the simulation method. The scenario responding to interest rate (“IR”) changes are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 NII(*1) NPV(*2) NII(*1) NPV(*2) Base case 4,497,407 23,856,916 4,916,138 23,472,792 Base case (Prepay) 4,491,363 23,546,002 4,916,015 23,163,942 IR 100bp up 5,022,303 23,803,250 5,361,546 22,886,122 IR 100bp down 4,051,601 23,933,844 4,386,437 24,127,559 IR 200bp up 5,992,145 23,766,488 5,806,723 22,372,208 IR 200bp down 3,672,050 24,043,703 3,452,590 24,830,482 IR 300bp up 6,848,435 23,742,304 6,251,897 21,929,189 IR 300bp down 3,527,210 24,201,770 2,254,609 26,633,807 (*1) NII: Net Interest Income (*2) NPV: Net Portfolio Value
Interest earning at risk and interest value at risk based on BIS framework for subsidiaries other than bank	The interest EaR and VaR calculated based on the BIS Framework of subsidiaries other than the Bank and consolidated trusts are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 EaR (*1) VaR (*2) EaR (*1) VaR (*2) 209,621 148,818 255,679 130,821 (*1) EaR: Earning at Risk (*2) VaR: Value at Risk
Cash flows of principal amounts and interests from interest bearing assets and liabilities by re-pricing date	The Group estimates and manages risks related to changes in interest rate due to the difference in the maturities of interest-bearing assets and liabilities and discrepancies in the terms of interest rates. Cash flows (both principal and interest) from non-trading, re-pricing June 30, 2018 Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over 5 Total Asset: Loans and other financial assets at amortized cost 148,324,408 41,273,662 9,372,945 8,650,081 47,212,644 4,314,787 259,148,527 Financial assets at FVTOCI 6,771,707 3,243,204 1,902,718 1,637,346 5,246,163 180,998 18,982,136 Securities at amortized cost 2,350,831 1,983,421 1,725,286 2,005,103 9,955,809 350,744 18,371,194 Total 157,446,946 46,500,287 13,000,949 12,292,530 62,414,616 4,846,529 296,501,857 Liability: Deposits due to customers 101,367,145 48,458,377 29,955,015 19,029,698 38,912,199 296,042 238,018,476 Borrowings 9,390,749 2,020,828 859,698 513,068 2,823,334 523,418 16,131,095 Debentures 979,221 1,801,149 2,183,459 2,407,879 18,625,611 2,727,547 28,724,866 Total 111,737,115 52,280,354 32,998,172 21,950,645 60,361,144 3,547,007 282,874,437 December 31, 2017 Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over 5 Total Asset: Loans and receivables 161,653,892 41,671,530 7,614,159 6,411,841 54,150,998 26,272,958 297,775,378 AFS financial assets 2,150,708 2,500,103 2,016,711 2,367,762 4,229,000 601,735 13,866,019 HTM financial assets 2,286,179 2,161,467 1,433,425 1,687,362 9,369,794 345,868 17,284,095 Total 166,090,779 46,333,100 11,064,295 10,466,965 67,749,792 27,220,561 328,925,492 Liability: Deposits due to customers 106,815,564 37,750,367 25,117,556 27,585,458 37,518,878 91,246 234,879,069 Borrowings 9,865,249 1,056,579 412,966 437,431 2,709,010 479,827 14,961,062 Debentures 1,955,902 2,452,240 1,018,563 1,752,847 19,770,538 2,869,766 29,819,856 Total 118,636,715 41,259,186 26,549,085 29,775,736 59,998,426 3,440,839 279,659,987
Foreign currency risk exposure of financial instruments in foreign currency	3) Currency risk Currency risk arises from the financial instruments denominated in foreign currencies other than the functional currency. Therefore, no currency risk arises from non-monetary Financial instruments in foreign currencies exposed to currency risk are as follows (Unit: USD in millions, JPY in millions, CNY in millions, EUR in millions, and Korean Won in millions): June 30, 2018 USD JPY CNY EUR Others Total Foreign Korean Foreign Korean Foreign Korean Foreign Korean Korean Korean Asset Loans and other financial assets at amortized cost 24,664 27,694,163 135,138 1,371,362 31,972 5,416,294 1,172 1,520,044 4,472,890 40,474,753 Financial assets at FVTPL 84 94,261 359 3,645 — — 36 46,488 75,122 219,516 Financial assets at FVTOCI 1,726 1,936,385 — — 300 50,874 — — 338,214 2,325,473 Securities at amortized cost 115 129,245 — — — — — — 105,949 235,194 Total 26,589 29,854,054 135,497 1,375,007 32,272 5,467,168 1,208 1,566,532 4,992,175 43,254,936 Liability Financial liabilities at FVTPL 63 70,963 505 5,127 — — 33 43,070 102,226 221,386 Deposits due to customer 11,160 12,517,349 145,058 1,472,035 21,633 3,664,842 1,230 1,595,651 2,700,164 21,950,041 Borrowings 6,417 7,201,536 2,211 22,438 — — 232 303,001 476,871 8,003,846 Debentures 3,708 4,159,175 — — — — — — 284,293 4,443,468 Other financial liabilities 3,240 3,633,942 23,541 238,890 5,568 943,321 140 182,002 4,602 5,002,757 Total 24,588 27,582,965 171,315 1,738,490 27,201 4,608,163 1,635 2,123,724 3,568,156 39,621,498 Off-balance 6,374 7,149,273 32,887 333,730 4,804 813,812 453 587,615 827,004 9,711,434 December 31, 2017 USD JPY CNY EUR Others Total Foreign Korean Foreign Korean Foreign Korean Foreign Korean Korean Korean Asset Loans and receivables 23,000 24,642,900 126,944 1,204,843 25,224 4,127,936 1,156 1,479,351 3,937,733 35,392,763 Financial assets at FVTPL 32 34,303 25 238 — — 27 34,583 104,892 174,016 AFS financial assets 1,966 2,105,972 — — 319 52,259 — 590 302,801 2,461,622 HTM financial assets 111 118,868 — — — — — — 78,175 197,043 Total 25,109 26,902,043 126,969 1,205,081 25,543 4,180,195 1,183 1,514,524 4,423,601 38,225,444 Liability Financial liabilities at FVTPL 41 43,423 79 752 — — 19 24,878 69,977 139,030 Deposits due to customer 13,744 14,725,686 195,176 1,852,440 21,865 3,578,142 883 1,129,802 2,396,826 23,682,896 Borrowings 6,604 7,080,118 2,218 21,056 — — 247 315,685 242,874 7,659,733 Debentures 3,467 3,714,411 — — 700 114,555 — — 375,749 4,204,715 Other financial liabilities 2,392 2,562,740 16,125 153,043 1,802 294,950 129 165,189 588,625 3,764,547 Total 26,248 28,126,378 213,598 2,027,291 24,367 3,987,647 1,278 1,635,554 3,674,051 39,450,921 Off-balance 8,108 8,687,009 33,624 319,127 1,199 196,261 406 519,843 176,886 9,899,126
Cash flow from principal and interest payments of non-derivative financial liabilities by remaining contractual maturities	a) Cash flows of principals and interests by remaining contractual maturities of non-derivative June 30, 2018 Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over Total Financial liabilities at FVTPL 176,097 — — — — — 176,097 Deposits due to customers 145,033,422 38,505,386 22,976,591 24,574,059 7,487,432 2,144,802 240,721,692 Borrowings 6,407,137 2,639,064 1,876,893 1,478,115 3,238,353 545,403 16,184,965 Debentures 979,221 1,801,149 2,183,459 2,407,879 18,626,696 2,726,462 28,724,866 Other financial liabilities 14,098,508 216,627 3,644 908 621,127 1,955,992 16,896,806 Total 166,694,385 43,162,226 27,040,587 28,460,961 29,973,608 7,372,659 302,704,426 December 31, 2017 Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over Total Financial liabilities at FVTPL 168,442 155,984 1,717 512 375 — 327,030 Deposits due to customers 148,008,777 29,563,310 18,175,348 32,468,110 7,409,118 2,624,594 238,249,257 Borrowings 6,115,732 1,893,173 1,489,272 1,178,107 3,924,681 479,568 15,080,533 Debentures 1,955,255 2,452,565 1,018,714 1,744,731 19,770,380 2,869,699 29,811,344 Other financial liabilities 7,121,342 162,871 825 1,003 128,940 2,730,001 10,144,982 Total 163,369,548 34,227,903 20,685,876 35,392,463 31,233,494 8,703,862 293,613,146
Cash flow from principal and interest payments of non-derivative financial liabilities by estimated redemption or withdrawal	b) Cash flows of principals and interests by expected maturities of non-derivative June 30, 2018 Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over 5 Total Financial liabilities at FVTPL 176,097 — — — — — 176,097 Deposits due to customers 154,934,637 40,340,567 20,220,152 18,154,029 6,115,894 348,774 240,114,053 Borrowings 6,407,137 2,639,064 1,876,893 1,478,115 3,242,839 540,917 16,184,965 Debentures 979,221 1,801,149 2,183,459 2,407,879 18,626,696 2,726,462 28,724,866 Other financial liabilities 14,098,508 216,627 3,644 908 621,127 1,955,992 16,896,806 Total 176,595,600 44,997,407 24,284,148 22,040,931 28,606,556 5,572,145 302,096,787 December 31, 2017 Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over 5 Total Financial liabilities at FVTPL 168,442 155,984 1,717 512 375 — 327,030 Deposits due to customers 159,146,602 31,298,562 16,667,130 21,995,294 6,487,047 2,278,756 237,873,391 Borrowings 6,115,732 1,893,173 1,489,272 1,178,107 3,924,681 479,568 15,080,533 Debentures 1,955,255 2,452,565 1,018,714 1,744,731 19,770,380 2,869,699 29,811,344 Other financial liabilities 7,121,342 162,871 825 1,003 128,940 2,730,001 10,144,982 Total 174,507,373 35,963,155 19,177,658 24,919,647 30,311,423 8,358,024 293,237,280
Cash flow of derivative financial liabilities by maturities	The cash flow by the maturity of derivative financial liabilities as of June 30, 2018 and December 31, 2017 is as follows (Unit: Korean Won in millions): Remaining maturity Within 3 4 to 6 7 to 9 10 to 12 1 to 5 Over 5 Total June 30, 2018 2,377,750 2,130 — — 59,820 5,555 2,445,255 December 31, 2017 3,150,149 — — 381 67,373 — 3,217,903
Maturity analysis of off-balance accounts	4) Maturity analysis of off-balance The Group provides guarantees on behalf of customers. A financial guarantee represents an irrevocable undertaking that the Group should meet a customer’s obligations to third parties if the customer fails to do so. Under a loan commitment, the Group agrees to make funds available to a customer in the future. Loan commitments that are usually for a specified term may persist or may be unconditionally cancellable, provided all conditions in the loan facility are satisfied or waived. Commitments to lend include commercial standby facilities and credit lines, liquidity facilities to commercial paper conduits and utilized overdraft facilities. The maximum limit to be paid by the Group in accordance with guarantees and loan commitment only applies to principal amounts. There are contractual maturities for financial guarantees, such as guarantees for debentures issued or loans, loan commitments, and other guarantees, however, under the terms of the guarantees and loan commitments, funds should be paid upon demand from the counterparty. Details of off-balance June 30, 2018 December 31, 2017 Guarantees 12,372,573 12,859,715 Loan commitments 98,251,005 80,760,325
Capital Ratio	Details of the Group’s capital adequacy ratio as of June 30, 2018 and December 31, 2017 are as follows (Unit: Korean Won in millions): June 30, 2018 (*) December 31, 2017 Tier 1 capital 16,952,436 16,074,987 Other Tier 1 capital 2,748,005 3,041,664 Tier 2 capital 3,499,122 3,486,555 Total risk-adjusted capital 23,199,563 22,603,206 Risk-weighted assets for credit risk 139,868,803 134,767,711 Risk-weighted assets for market risk 2,292,979 2,316,938 Risk-weighted assets for operational risk 9,826,809 9,677,559 Total risk-weighted assets 151,988,591 146,762,208 Common Equity Tier 1 ratio 11.15 % 10.95 % Tier 1 capital ratio 12.96 % 13.03 % Total capital ratio 15.26 % 15.40 % (*) Capital adequacy ratio as of June 30, 2018 is tentatively measured.

Operating Segments (Tables)

Operating Segments (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of operating segments [Abstract]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	The details of operating income by each segment are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Consumer Corporate Investment Capital Credit cards Headquarters Subtotal Adjustments Total Net Interest income Interest income 1,703,521 1,638,747 74,670 5,687 323,443 747,596 4,493,664 149,752 4,643,416 Interest expense (499,830 ) (994,523 ) (92 ) — (75,716 ) (458,733 ) (2,028,894 ) 149,952 (1,878,942 ) Inter-segment (274,405 ) 323,139 (77,656 ) 10,259 — 18,663 — — — 929,286 967,363 (3,078 ) 15,946 247,727 307,526 2,464,770 299,704 2,764,474 Net non-interest Non-interest 405,145 432,262 137,031 4,765,167 605,165 516,766 6,861,536 (236,269 ) 6,625,267 Non-interest (127,357 ) (183,814 ) (40,188 ) (4,725,584 ) (562,210 ) (218,710 ) (5,857,863 ) (182,141 ) (6,040,004 ) Inter-segment 78,522 36,407 — — — (114,929 ) — — — 356,310 284,855 96,843 39,583 42,955 183,127 1,003,673 (418,410 ) 585,263 Other income (expense) Administrative expense (875,328 ) (403,216 ) (5,689 ) (7,852 ) (83,575 ) (327,244 ) (1,702,904 ) 135,566 (1,567,338 ) Reversal of allowance for credit loss and impairment losses due to credit loss (53,008 ) 109,283 52,244 (3,268 ) (113,960 ) 62,729 54,020 (28,704 ) 25,316 (928,336 ) (293,933 ) 46,555 (11,120 ) (197,535 ) (264,515 ) (1,648,884 ) 106,862 (1,542,022 ) Operating income (expenses) 357,260 958,285 140,320 44,409 93,147 226,138 1,819,559 (11,844 ) 1,807,715 Non-operating (9,889 ) 671 17,411 — (2,988 ) 17,615 22,820 (29,003 ) (6,183 ) Net income before income tax expense 347,371 958,956 157,731 44,409 90,159 243,753 1,842,379 (40,847 ) 1,801,532 Income tax expense (95,528 ) (260,186 ) (43,377 ) (12,212 ) (22,541 ) (52,320 ) (486,164 ) 948 (485,216 ) Net income 251,843 698,770 114,354 32,197 67,618 191,433 1,356,215 (39,899 ) 1,316,316 For the six months ended June 30, 2017 Consumer Corporate Investment Capital Credit cards Headquarters Subtotal Adjustments Total Net Interest income Interest income 1,539,729 1,456,198 72,232 8,938 288,648 668,644 4,034,389 155,195 4,189,584 Interest expense (480,814 ) (818,422 ) (126 ) — (65,600 ) (411,449 ) (1,776,411 ) 137,147 (1,639,264 ) Inter-segment (248,116 ) 229,029 (66,693 ) 8,324 — 77,456 — — — 810,799 866,805 5,413 17,262 223,048 334,651 2,257,978 292,342 2,550,320 Net non-interest Non-interest 424,214 333,646 212,107 4,991,598 566,107 1,129,696 7,657,368 (126,727 ) 7,530,641 Non-interest (146,630 ) (82,261 ) (121,238 ) (4,968,840 ) (520,469 ) (862,571 ) (6,702,009 ) (240,504 ) (6,942,513 ) Inter-segment 45,402 29,680 — — — (75,082 ) — — — 322,986 281,065 90,869 22,758 45,638 192,043 955,359 (367,231 ) 588,128 For the six months ended June 30, 2017 Consumer Corporate Investment Capital Credit Headquarters Subtotal Adjustments Total Other income (expense) General and administrative expense (869,732 ) (402,661 ) (5,696 ) (7,721 ) (77,909 ) (298,578 ) (1,662,297 ) 123,870 (1,538,427 ) Reversal of allowance for credit loss and impairment losses due to credit loss (45,964 ) (128,685 ) 31,311 22,135 (106,698 ) 152,836 (75,065 ) (40,728 ) (115,793 ) (915,696 ) (531,346 ) 25,615 14,414 (184,607 ) (145,742 ) (1,737,362 ) 83,142 (1,654,220 ) Operating income 218,089 616,524 121,897 54,434 84,079 380,952 1,475,975 8,253 1,484,228 Non-operating 8,862 (3,122 ) 22,581 — (2,399 ) (26,180 ) (258 ) (54,022 ) (54,280 ) Net income before income tax expense 226,951 613,402 144,478 54,434 81,680 354,772 1,475,717 (45,769 ) 1,429,948 Income tax expense (54,923 ) (139,138 ) (34,964 ) (13,173 ) (19,816 ) (50,841 ) (312,855 ) (8,078 ) (320,933 ) Net income 172,028 474,264 109,514 41,261 61,864 303,931 1,162,862 (53,847 ) 1,109,015

Cash and cash equivalents (Tabl

Cash and cash equivalents (Tables)	6 Months Ended
	Jun. 30, 2018
Cash and cash equivalents [Abstract]
Schedule of Cash and Cash Equivalents	(1) Details of cash and cash equivalents are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Cash 1,889,739 2,009,363 Foreign currencies 795,692 617,155 Demand deposits 2,777,874 3,423,355 Fixed deposits 457,263 858,413 Total 5,920,568 6,908,286
Schedule of Other Significant Noncash Transactions	(2) Significant transactions of investing activities and financing activities not involving cash inflows and outflows are as follows (Unit: Korean Won in millions): For the For the Changes in other comprehensive gain due to remeasurement of financial assets designated at FVTOCI 41,452 — Changes in other comprehensive loss due to valuation of AFS financial assets — (28,706 ) Changes in other comprehensive income of investment in associates 1,210 1,507 Changes in other comprehensive gain (loss) of foreign operations translation 35,526 (69,010 ) Changes in other comprehensive loss related to valuation of cash flow hedging (6,213 ) (1,526 ) Changes in other comprehensive loss due to remeasurement of the net defined benefit liability (59,573 ) (9,677 ) Changes in investments in associates due to debt-equity swap — 51,405 Changes in investments in associates due to accounts transfer (5,865 ) (16,354 ) Changes in accrued dividends of hybrid equity securities (80 ) (9,804 ) Changes in intangible assets related to accounts payable 32,369 (8,506 ) Classified to assets held for sale from premises and equipment 6,050 2,184

Financial assets at fair valu59

Financial assets at fair value through profit or loss (Tables)	6 Months Ended
	Jun. 30, 2018
Financial assets at fair value through profit or loss [Abstract]
Financial assets at fair value through profit or loss	(1) Financial assets at FVTPL are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Financial assets at fair value through profit or loss mandatorily measured at fair value 6,340,704 — Financial assets held for trading — 5,820,787 Financial assets designated at FVTPL — 22,290 Total 6,340,704 5,843,077
Financial assets at fair value through profit or loss and financial assets held for trading	(2) Financial assets at fair value through profit or loss mandatorily measured at fair value and financial assets held for trading are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Deposits: Gold banking asset 24,921 25,972 Securities: Debt securities Korean treasury and government agencies 639,476 540,438 Financial institutions 639,711 1,476,498 Corporates 714,508 627,397 Others 156 — June 30, 2018 December 31, 2017 Equity securities 433,316 21,666 Capital contributions 349,470 — Beneficiary certificates 810,968 13,041 Subtotal 3,587,605 2,679,040 Loans 336,967 — Derivatives assets 2,391,211 3,115,775 Total 6,340,704 5,820,787
Financial assets designated at fair value through profit or loss	(3) Financial assets at fair value through profit or loss designated as upon initial recognition as of June 30, 2018 and financial assets at fair value through profit or loss designated as upon initial recognition as of December 31, 2017 are as follows (Unit: Korean Won in millions): December 31, 2017 Debt securities 9,694 Equity securities 12,596 Total 22,290

Financial assets at fair valu60

Financial assets at fair value through other comprehensive income and available-for-sale financial assets (Tables)	6 Months Ended
	Jun. 30, 2018
Financial assets at fair falue through other comprehensive income and available-for-sale financial assets [Abstract]
Details of financial assets at fair value through other comprehensive income and available for sale financial assets	(1) Details of financial assets at FVTOCI as of June 30, 2018 and AFS financial assets as of December 31, 2017 are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Debt securities: Korean treasury and government agencies 2,195,526 2,330,567 Financial institutions 7,370,107 5,217,266 Corporates 1,797,635 2,725,232 Asset-backed securities — 308,181 Bond denominated in foreign currencies 2,325,422 2,442,579 Others — 35,163 Subtotal 13,688,690 13,058,988 Equity securities 905,779 1,411,078 Beneficiary certificates — 712,628 Securities loaned 50,139 170,256 Total 14,644,608 15,352,950
Details of equity securities designated as financial assets at fair value through other comprehensive income	(2) Details of equity securities designated as financial assets at FVTOCI are as follows (Unit: Korean Won in millions): June 30, 2018 Purpose of acquisition Fair value Strategic business partnership 737,104 Debt-equity swap 168,533 Others(*) 142 Total 905,779 (*) Cooperate insurance, etc.
Changes in loss allowance and gross carrying amount of financial assets at fair value through other comprehensive income	1) Loss allowance For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance (*1) (4,107 ) (129 ) — (4,236 ) Transfer to 12-month — — — — Transfer to lifetime expected credit losses — — — — Transfer to credit-impaired financial assets — — — — Net reversal (provision) of loss allowance (562 ) 103 — (459 ) Disposal 27 — — 27 Others (*2) (2 ) — — (2 ) Ending balance (4,644 ) (26 ) — (4,670 ) (*1) The beginning balance was restated in accordance with IFRS 9. (*2) Others consist of foreign currencies translation, etc.
Changes in gross carrying amount of financial assets at fair value through other comprehensive income	2) Gross carrying amount For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance 12,843,997 30,212 — 12,874,209 Transfer to 12-month — — — — Transfer to lifetime expected credit losses — — — — Transfer to credit-impaired financial assets — — — — Acquisition 5,075,597 — — 5,075,597 Disposal (4,294,135 ) (15,047 ) — (4,309,182 ) Gain (loss) on valuation 12,874 10 — 12,884 Amortization on the effective interest method (2,289 ) — — (2,289 ) Others (*) 87,610 — — 87,610 Ending balance 13,723,654 15,175 — 13,738,829 (*) Others consist of foreign currencies translation, etc.

Securities at amortized cost 61

Securities at amortized cost and Held to maturity financial assets (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of securities at amortized cost and held to maturity financial assets [Abstract]
Details of securities at amortized cost and held to maturity financial assets	(1) Details of securities at amortized cost as of June 30, 2018 and HTM financial assets as of December 31, 2017 are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Korean treasury and government agencies 4,630,598 3,994,857 Financial institutions 7,767,490 7,245,426 Corporates 5,074,097 5,311,970 Bond denominated in foreign currencies 235,194 197,043 Loss allowance (5,250 ) — Total 17,702,129 16,749,296
Changes in loss allowance and gross carrying amount of securities at amortized cost	1) Loss allowance For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance (*1) (5,078 ) — — (5,078 ) Transfer to 12-month — — — — Transfer to lifetime expected credit losses — — — — Transfer to credit-impaired financial assets — — — — Net provision of loss allowance (191 ) — — (191 ) Disposal 22 — — 22 Others (*2) (3 ) — — (3 ) Ending balance (5,250 ) — — (5,250 ) (*1) The beginning balance was restated in accordance with IFRS 9. (*2) Others consist of foreign currencies translation, etc.
Changes in loss allowance and gross carrying amount of securities at amortized cost	2) Gross carrying amount For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance 16,749,296 — — 16,749,296 Transfer to 12-month — — — — Transfer to lifetime expected credit losses — — — — Transfer to credit-impaired financial assets — — — — Acquisition 5,829,462 — — 5,829,462 Disposal / Redemption (4,873,896 ) — — (4,873,896 ) Amortization on the effective interest method (6,008 ) — — (6,008 ) Others (*) 8,525 — — 8,525 Ending balance 17,707,379 — — 17,707,379 (*) Others consist of foreign currencies translation, etc.

Loans and other financial ass62

Loans and other financial assets at amortized cost and loans and receivables (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of loans and receivables [Abstract]
Details of loans and other financial assets at amortized cost and loans and receivables	(1) Details of loans and other financial assets at amortized cost as of June 30, 2018 and loans and receivables as of December 31, 2017 are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Due from banks 17,770,356 8,868,378 Loans 248,794,014 251,523,301 Other financial assets (other receivables) 11,155,633 6,714,525 Total 277,720,003 267,106,204
Details of due from banks	(2) Details of due from banks are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Due from banks in local currency: Due from The Bank of Korea (“BOK”) 14,500,746 6,246,496 Due from depository banks 90,003 30,003 Due from non-depository 33 150 Due from the Korea Exchange — 50,000 Others 68,132 97,365 Loss allowance (3,475 ) (1,541 ) Subtotal 14,655,439 6,422,473 Due from banks in foreign currencies: Due from banks on demand 1,055,513 794,353 Due from banks on time 1,237,312 972,915 Others 824,229 679,554 Loss allowance (2,137 ) (917 ) Subtotal 3,114,917 2,445,905 Total 17,770,356 8,868,378
Details of restricted due from banks	(3) Details of restricted due from banks are as follows (Unit: Korean Won in millions): Counterparty June 30, 2018 Reason of restriction Due from banks in local currency: Due from BOK The BOK 14,500,746 Reserve deposits under the BOK Act Others The Korea Exchange and others 64,150 Central counterparty KRW margin and others Subtotal 14,564,896 Due from banks in foreign currencies: Due from banks on demand The BOK and others 1,048,609 Reserve deposits under the BOK Act and others Others The People’s Bank of China and others 824,229 Reserve deposits and others Due from banks on time National Bank of Cambodia 56 Fast And Secure Transfer (Payment system) Subtotal 1,872,894 Total 16,437,790 Counterparty December 31, 2017 Reason of restriction Due from banks in local currency: Due from BOK The BOK 6,246,496 Reserve deposits under the BOK Act Others The Korea Exchange and others 94,394 Central counterparty KRW margin and others Subtotal 6,340,890 Counterparty December 31, 2017 Reason of restriction Due from banks in foreign currencies: Due from banks on demand The BOK and others 787,520 Reserve deposits under the BOK Act and others Others The People’s Bank of China and others 367,108 Reserve deposits and others Subtotal 1,154,628 Total 7,495,518
Changes in loss allowance of due from banks	1) Loss allowance For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance (*1) (3,092 ) — — (3,092 ) Transfer to 12-month — — — — Transfer to lifetime expected credit losses — — — — Transfer to credit-impaired financial assets — — — — Net provision of loss allowance (2,500 ) — — (2,500 ) Others (*2) (20 ) — — (20 ) Ending balance (5,612 ) — — (5,612 ) (*1) The beginning balance was restated in accordance with IFRS 9. (*2) Others consist of foreign currencies translation and etc.
Changes in gross carrying amount of due from banks	2) Gross carrying amount For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance 8,870,835 — — 8,870,835 Transfer to 12-month — — — — Transfer to lifetime expected credit losses — — — — Transfer to credit-impaired financial assets — — — — Net increase 8,855,041 — — 8,855,041 Others (*) 50,092 — — 50,092 Ending balance 17,775,968 — — 17,775,968 (*) Others consist of foreign currencies translation and etc.
Details of loans	(5) Details of loans are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Loans in local currency 204,830,133 200,213,230 Loans in foreign currencies 14,731,407 13,147,888 Domestic banker’s letter of credit 3,074,011 2,516,907 Credit card accounts 7,570,281 6,827,295 Bills bought in foreign currencies 6,830,374 8,197,159 Bills bought in local currency 257,405 334,714 Factoring receivables 61,382 137,523 June 30, 2018 December 31, 2017 Advances for customers on guarantees 14,910 23,620 Private placement bonds 433,591 362,319 Securitized loans 1,228,212 563,152 Call loans 3,135,670 3,003,455 Bonds purchased under resale agreements 6,999,881 16,859,064 Loan origination costs and fees 545,864 510,860 Others 836,266 607,325 Discounted present value (5,068 ) (10,988 ) Loss allowance (1,750,305 ) (1,770,222 ) Total 248,794,014 251,523,301
Changes in loss allowance of loans	(6) Changes in the loss allowance on loans for the six months ended June 30, 2018 are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Consumers Corporates Stage 1 Stage 2 Stage 3 Stage 1 Stage 2 Stage 3 Beginning balance (*1) (101,479 ) (41,358 ) (117,168 ) (365,246 ) (255,926 ) (905,243 ) Transfer to 12-month (9,219 ) 8,797 421 (20,913 ) 20,634 280 Transfer to lifetime expected credit losses 6,076 (7,514 ) 1,438 17,263 (106,963 ) 89,700 Transfer to credit-impaired financial assets 19,177 23,228 (42,406 ) 2,976 12,016 (14,991 ) Net reversal (provision) of loss allowance (22,903 ) (29,025 ) (51,219 ) (5,600 ) 30,121 154,111 Recoveries of loans previously charged off — — (23,392 ) — — (52,273 ) Charge-off — — 117,228 — — 121,847 Disposal — — 780 — 67 17,676 Unwinding effect — — 3,665 — — 12,961 Others (*2) (1,994 ) (39 ) (1,156 ) 23,916 (87 ) (312 ) Ending balance (110,342 ) (45,911 ) (111,809 ) (347,604 ) (300,138 ) (576,244 ) For the six months ended June 30, 2018 Credit card accounts Sub-total Stage 1 Stage 2 Stage 3 Stage 1 Stage 2 Stage 3 Beginning balance (*1) (57,134 ) (71,463 ) (102,858 ) (523,859 ) (368,747 ) (1,125,269 ) Transfer to 12-month (12,969 ) 12,880 89 (43,101 ) 42,311 790 Transfer to lifetime expected credit losses 6,963 (7,307 ) 344 30,302 (121,784 ) 91,482 Transfer to credit-impaired financial assets 698 2,537 (3,235 ) 22,851 37,781 (60,632 ) Net reversal (provision) of loss allowance (409 ) (11,715 ) (90,448 ) (28,912 ) (10,619 ) 12,444 Recoveries of loans previously charged off — — (28,706 ) — — (104,371 ) Charge-off — — 104,478 — — 343,553 Disposal — — — — 67 18,456 Unwinding effect — — — — — 16,626 Others (*2) (2 ) — — 21,920 (126 ) (1,468 ) Ending balance (62,853 ) (75,068 ) (120,336 ) (520,799 ) (421,117 ) (808,389 ) (*1) The beginning balance was restated in accordance with IFRS 9. (*2) Others consist of debt-equity swap, foreign currencies translation and etc.
Changes in allowance for credit losses of loans and receivables	Changes in the loss allowances on loans and receivables for the six months ended June 30, 2017 are as follows (Unit: Korean Won in millions): For six months ended June 30, 2017 Consumers Corporates Credit card Others Total Beginning balance (163,858 ) (1,498,842 ) (155,372 ) (209,024 ) (2,027,096 ) Net reversal (provision) of loss allowance (65,582 ) (191,263 ) (91,022 ) 13,891 (333,976 ) Recoveries of loans previously charged off (21,659 ) (55,319 ) (24,808 ) (3 ) (101,789 ) Charge-off 67,593 220,598 104,195 51,260 443,646 Disposal 830 58,431 — 29,264 88,525 Unwinding effect 4,620 20,047 — — 24,667 Others (*) 416 179,068 — (633 ) 178,851 Ending balance (177,640 ) (1,267,280 ) (167,007 ) (115,245 ) (1,727,172 ) (*) Others consist of debt-equity swap, foreign currencies translation and etc.
Changes in gross carrying amount of loans	(7) Changes in the gross carrying amount of loans are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Consumers Corporates Stage 1 Stage 2 Stage 3 Stage 1 Stage 2 Stage 3 Beginning balance 103,502,347 5,487,758 326,739 130,561,786 5,000,966 1,622,410 Transfer to 12-month 1,772,982 (1,768,978 ) (4,004 ) 1,113,857 (1,112,533 ) (1,324 ) Transfer to lifetime expected credit losses (2,731,516 ) 2,746,818 (15,302 ) (2,112,755 ) 2,222,364 (109,609 ) Transfer to credit-impaired financial assets (84,885 ) (101,151 ) 186,036 (155,933 ) (118,707 ) 274,640 Charge-off — — (117,228 ) — — (121,847 ) Disposal — (270 ) (13,483 ) — (883 ) (67,695 ) Net increase (decrease) 2,913,765 (742,949 ) (22,980 ) (4,520,684 ) (688,875 ) (149,456 ) Ending balance 105,372,693 5,621,228 339,778 124,886,271 5,302,332 1,447,119 For the six months ended June 30, 2018 Credit card accounts Sub-total Stage 1 Stage 2 Stage 3 Stage 1 Stage 2 Stage 3 Beginning balance 5,721,743 935,266 177,983 239,785,876 11,423,990 2,127,132 Transfer to 12-month 243,044 (242,932 ) (112 ) 3,129,883 (3,124,443 ) (5,440 ) Transfer to lifetime expected credit losses (299,729 ) 300,190 (461 ) (5,144,000 ) 5,269,372 (125,372 ) Transfer to credit-impaired financial assets (27,288 ) (24,128 ) 51,416 (268,106 ) (243,986 ) 512,092 Charge-off — — (104,478 ) — — (343,553 ) Disposal — — — — (1,153 ) (81,178 ) Net increase (decrease) 722,640 46,551 75,193 (884,279 ) (1,385,273 ) (97,243 ) Ending balance 6,360,410 1,014,947 199,541 236,619,374 11,938,507 1,986,438
Details of other receivables	(8) Details of other financial assets (other receivables) are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 CMA accounts 200,000 135,000 Receivables 8,721,745 4,459,318 Accrued income 1,055,713 1,026,273 Telex and telephone subscription rights and refundable deposits 980,611 984,620 Other receivables 272,403 166,877 Loss allowance (74,839 ) (57,563 ) Total 11,155,633 6,714,525
Changes in loss allowance of other receivables	(9) Changes in the loss allowances on other financial assets are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance (*) (2,955 ) (1,832 ) (54,211 ) (58,998 ) Transfer to 12-month (161 ) 146 15 — Transfer to lifetime expected credit losses 112 (122 ) 10 — Transfer to credit-impaired financial assets 23 167 (190 ) — Net provision of loss allowance (360 ) (256 ) (30,854 ) (31,470 ) Recoveries of other financial assets previously charged off — — (2 ) (2 ) Charge-off — — 15,225 15,225 Disposal — — 593 593 Others (208 ) — 21 (187 ) Ending balance (3,549 ) (1,897 ) (69,393 ) (74,839 ) (*) The beginning balance was restated in accordance with IFRS 9.
Changes in gross carrying amount of other receivables	(10) Changes in the gross carrying amount of other financial assets are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Stage 1 Stage 2 Stage 3 Total Beginning balance 6,662,335 29,124 79,912 6,771,371 Transfer to 12-month 8,130 (8,109 ) (21 ) — Transfer to lifetime expected credit losses (10,935 ) 10,949 (14 ) — Transfer to credit-impaired financial assets (768 ) (1,120 ) 1,888 — Charge-off — — (15,225 ) (15,225 ) Disposal — (2 ) (735 ) (737 ) Net increase and others 4,460,291 (1,650 ) 16,422 4,475,063 Ending balance 11,119,053 29,192 82,227 11,230,472

Fair value of financial asset63

Fair value of financial assets and liabilities (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of fair value measurement [Abstract]
Schedule of fair value measurement of financial instruments [Table Text Block]	(2) Fair value hierarchy of financial assets and liabilities measured at fair value are as follows (Unit: Korean Won in millions): June 30, 2018 Level 1 (*1) Level 2 (*1) Level 3 Total Financial assets: Financial assets at fair value through profit or loss mandatorily measured at fair value Deposits 24,921 — — 24,921 Debt securities 375,280 1,611,129 7,442 1,993,851 Equity securities 80,536 — 352,780 433,316 Capital contributions — — 349,470 349,470 Beneficiary certificates — 62,173 748,795 810,968 Loans — 85,000 251,967 336,967 Derivative assets 17,439 2,337,601 36,171 2,391,211 Subtotal 498,176 4,095,903 1,746,625 6,340,704 Financial assets at FVTOCI Debt securities 2,463,992 11,224,698 — 13,688,690 Equity securities 440,038 — 465,741 905,779 Securities loaned — 50,139 — 50,139 Subtotal 2,904,030 11,274,837 465,741 14,644,608 Derivative assets — 12,395 — 12,395 Total 3,402,206 15,383,135 2,212,366 20,997,707 June 30, 2018 Level 1 (*1) Level 2 (*1) Level 3 Total Financial liabilities: Financial liabilities at fair value through profit or loss mandatorily measured at fair value Deposits due to customers 24,485 — — 24,485 Derivative liabilities 3,269 2,333,558 40,923 2,377,750 Subtotal 27,754 2,333,558 40,923 2,402,235 Financial liabilities at fair value through profit or loss designated as upon initial recognition Equity-linked securities — — 176,097 176,097 Derivative liabilities — 67,505 — 67,505 Total 27,754 2,401,063 217,020 2,645,837 December 31, 2017 Level 1 (*1) Level 2 (*1) Level 3 (*2) Total Financial assets: Financial assets held for trading Deposits 25,972 — — 25,972 Debt securities 405,942 2,238,391 — 2,644,333 Equity securities 21,666 — — 21,666 Beneficiary certificates — 13,041 — 13,041 Derivative assets 1,021 3,093,272 21,482 3,115,775 Subtotal 454,601 5,344,704 21,482 5,820,787 Financial assets designated at FVTPL Debt securities — — 9,694 9,694 Equity securities — — 12,596 12,596 Subtotal — — 22,290 22,290 AFS financial assets Debt securities 2,710,172 10,348,816 — 13,058,988 Equity securities 399,214 — 1,011,864 1,411,078 Beneficiary certificates — 68,722 643,906 712,628 Securities loaned 69,778 100,478 — 170,256 Subtotal 3,179,164 10,518,016 1,655,770 15,352,950 Derivative assets — 59,272 — 59,272 Total 3,633,765 15,921,992 1,699,542 21,255,299 Financial liabilities: Financial liabilities held for trading Deposits due to customers 25,964 — — 25,964 Derivative liabilities 2,613 3,126,585 20,951 3,150,149 Subtotal 28,577 3,126,585 20,951 3,176,113 Financial liabilities designated at FVTPL Equity-linked securities — — 160,057 160,057 Debentures — 91,739 — 91,739 Subtotal — 91,739 160,057 251,796 Derivative liabilities — 67,754 — 67,754 Total 28,577 3,286,078 181,008 3,495,663 (*1) There were no transfers between Level 1 and Level 2 of financial assets and liabilities measured at fair value. The Group recognizes transfers among levels at the end of reporting period in which events have occurred or conditions have changed. (*2) Certain AFS unquoted equity securities were measured at cost as of December 31, 2017, that amounted to 37,092 million Won. These unquoted equity instruments mostly represent minority investments in structured entity vehicles, such as asset securitization structures. They are measured at cost because (a) observable inputs of financial information to measure fair value were not available to obtain, (b) there was a significant variance in likely estimated cash flows or (c) the probabilities for various estimated cash flows could not be measured reliably. In addition, the Group has no intention to dispose these investments in the foreseeable future.
Valuation techniques and inputs used in fair value measurement of financial instruments measured at fair value [Table Text Block]	Financial instruments are measured at fair value using a quoted market price in active markets. If there is no active market for a financial instrument, the Group determines the fair value using valuation methods. Valuation methods and input variables for each type of financial instruments are as follows: Valuation methods Input variables Loans The fair value of Loans is measured by the Binomial tree given the values of underlying assets and volatility. Values of underlying assets, Volatility Debt securities The fair value is measured by discounting the projected cash flows of debt securities by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the issuers of the securities. Risk-free market rate, credit spread Equity securities, capital contribution and Beneficiary certificates Among DCF (Discounted Cash Flow) Model, FCFE (Free Cash Flow to Equity) Model, Comparable Company Analysis, Dividend Discount Model, Risk-adjusted Rate of Return Method, and Net Asset Value Method, more than one method is used given the characteristic of the subject of fair value measurement. Risk-free market rate, market risk premium, Beta, etc. Valuation methods Input variables Derivatives The in-house However, for some complicated financial instruments of which valuation should be based on some assumptions since some significant or all inputs to be used in the model are not observable in the market, the in-house Risk-free market rate, forward rate, volatility, foreign exchange rate, stock prices, etc. Equity-linked securities The fair value of security linked to stock prices or derivatives is measured by the models such as DCF model, FDM, or Monte Carlo Simulation given the natures of the securities or underlying assets. Values of underlying assets, risk-free market rate, market rate, dividend and convenience yield, volatility, correlation coefficient, credit spread, and foreign exchange rate Debentures The fair value is measured by discounting the projected cash flows of a debenture by applying the market discount rate that is reflecting credit rating of the Group. Risk-free market rate, forward rate
Schedule of significant unobservable inputs used in fair value measurement of financial assets and liabilities [Table Text Block]	Valuation methods of financial assets and liabilities measured at fair value and classified into Level 3 and significant but unobservable inputs are as follows: Fair value measurement Input variable Range Impact of changes in significant unobservable Loans Binomial tree Stock, Volatility of underlying asset 14.92% – 41.24% Variation of fair value increases as volatility increases. Derivative assets Option valuation model and others Correlation coefficient 0.900 – 0.970 Variation of fair value increases as correlation coefficient increases. Volatility of underlying asset 10.61% – 27.59% Variation of fair value increases as volatility increases. Derivative liabilities Option valuation model and others Correlation coefficient 0.900 – 0.970 Variation of fair value increases as correlation coefficient increases. Volatility of underlying asset 10.61% – 27.59% Variation of fair value increases as volatility increases. Equity-linked securities Monte Carlo Simulation and others Correlation coefficient 0.0861 – 0.688 Equity-linked securities’ variation of fair value increases if both volatility and correlation coefficient increase. However, when correlation coefficient decreases despite the increase in volatility, the variation of fair value of a compound financial instrument may decrease. Volatility of underlying asset 18.60% – 26.88% Equity securities and beneficiary certificates External appraisal value and others Expected growth rate 0.00% Fair value increases as expected growth rate increases. Discount rate 0.99% – 18.73% Fair value increases as discount rate decreases. Volatility of real estate sale price 0.00% Fair value increases as sale price increases.
Reconciliation of changes in financial assets and liabilities classified as level3 of fair value hierarchy [Table Text Block]	(3) Changes in financial assets and liabilities measured at fair value classified into Level 3 are as follows (Unit: Korean Won in millions): For six months ended June 30, 2018 January 1, Net Other Purchases/ Disposals/ Transfer to June 30, Financial assets: Financial assets at fair value through profit or loss mandatorily measured at fair value Debt securities 9,694 (111 ) — — (2,141 ) — 7,442 Equity securities 280,171 22,834 — 50,005 (230 ) — 352,780 Capital contributions 294,121 21,934 — 49,367 (15,952 ) — 349,470 Beneficiary certificates 654,066 12,973 — 1,924,763 (1,843,007 ) — 748,795 Loans 165,001 3,616 — 125,807 (42,457 ) — 251,967 Derivative assets 19,346 65,856 — 1,936 (50,967 ) — 36,171 Subtotal 1,422,399 127,102 — 2,151,878 (1,954,754 ) — 1,746,625 Financial assets at FVTOCI Equity securities 451,287 (393 ) 14,557 290 — — 465,741 Total 1,873,686 126,709 14,557 2,152,168 (1,954,754 ) — 2,212,366 Financial liabilities: Financial liabilities at fair value through profit or loss mandatorily measured at fair value Derivative liabilities 20,951 73,951 — (3,058 ) (50,921 ) — 40,923 Financial liabilities at fair value through profit or loss designated as upon initial recognition Equity-linked securities 160,057 (1,438 ) — 179,044 (161,566 ) — 176,097 Total 181,008 72,513 — 175,986 (212,487 ) — 217,020 (*1) The losses that increase financial liabilities are presented as positive amounts, and the gains that decrease financial liabilities are presented as negative amounts. The gain amounting to 61,323 million Won for six months ended June 30, 2018, which is from financial assets and liabilities that the Group holds as at the end of the periods, has been recognized in net gain (loss) on financial assets at FVTPL and net gain (loss) on financial assets at FVTOCI in the consolidated statement of comprehensive income. (*2) The Group recognizes transfers between levels at the end of reporting period within which events have occurred or conditions have changed. For the six months ended June 30, 2017 January 1, Net Other Purchases/ Disposals/ Transfer to June 30, Financial assets: Financial assets held for trading Derivative assets 23,153 21,217 — 472 (17,420 ) — 27,422 Financial assets designed at FVTPL Debt securities 4,348 191 — 2,000 — — 6,539 Equity securities 12,652 (207 ) — — — — 12,445 Sub-total 17,000 (16 ) — 2,000 — — 18,984 For the six months ended June 30, 2017 January 1, Net Other Purchases/ Disposals/ Transfer to June 30, AFS financial assets Equity securities 1,024,935 19,241 10,175 27,289 (31,692 ) — 1,049,948 Beneficiary certificates 530,511 3,442 (2,188 ) 127,147 (70,600 ) — 588,312 Sub-total 1,555,446 22,683 7,987 154,436 (102,292 ) — 1,638,260 Derivative assets 99 185 — — (284 ) — — Total 1,595,698 44,069 7,987 156,908 (119,996 ) — 1,684,666 Financial liabilities: Financial liabilities held for trading Derivative liabilities 33,524 14,142 — 501 (15,015 ) — 33,152 Financial liabilities designated at FVTPL Equity-linked securities 673,709 83,962 — — (235,296 ) — 522,375 Total 707,233 98,104 — 501 (250,311 ) — 555,527 (*1) The loss amounting to 61,518 million Won for the six months ended June 30, 2017, which is from financial assets and liabilities that the Group holds, has been recognized in net gain (loss) on financial instruments at FVTPL and net gain (loss) on AFS financial assets in the statement of comprehensive income. (*2) The Group recognizes transfers between levels at the end of reporting period within which events have occurred or conditions have changed.
Schedule of sensitivity analysis dueto one or more unobservable inputs on fair value of level3 financial instruments [Table Text Block]	The following table presents the sensitivity analysis to disclose the effect of reasonably possible volatility on the fair value of a Level 3 financial instruments (Unit: Korean Won in millions): June 30, 2018 Net income (loss) Other comprehensive income (loss) Favorable Unfavorable Favorable Unfavorable Financial assets: Financial assets at FVTPL Derivative assets (*1) (*2) 4,305 (2,452 ) — — Loans 422 (323 ) — — Debt securities 914 (784 ) — — Equity securities (*3) (*4) 10,740 (7,562 ) — — Beneficiary certificates (*4) 1,436 (1,544 ) — — Financial assets at FVTOCI Equity securities (*3) (*4) — — 19,464 (8,704 ) Total 17,817 (12,665 ) 19,464 (8,704 ) June 30, 2018 Net income (loss) Other comprehensive income (loss) Favorable Unfavorable Favorable Unfavorable Financial liabilities: Financial liabilities at fair value through profit or loss mandatorily measured at fair value Derivative liabilities (*1) (*2) 2,409 (4,285 ) — — Financial liabilities at fair value through profit or loss designated as upon initial recognition Equity-linked securities (*1) 1,083 (1,158 ) — — Total 3,492 (5,443 ) — — December 31, 2017 Net income (loss) Other comprehensive income (loss) Favorable Unfavorable Favorable Unfavorable Financial assets: Financial assets held for trading Derivatives assets (*1) (*2) 1,234 (526 ) — — Financial assets designed at FVTPL Debt securities (*5) 265 (309 ) — — Equity securities (*5) 670 (624 ) — — AFS Financial assets Equity securities (*3) (*4) — — 28,583 (15,246 ) Beneficiary certificates (*4) — — 1,861 (1,857 ) Total 2,169 (1,459 ) 30,444 (17,103 ) Financial liabilities: Financial liabilities held for trading Derivative liabilities (*1) (*2) 5 (513 ) — — Financial liabilities designated at FVTPL Equity-linked securities (*1) 8 (7 ) — — Total 13 (520 ) — — (*1) Fair value changes of equity related derivatives assets and liabilities and equity-linked securities are calculated by increasing or decreasing historical volatility of the stock price and correlation, which are major unobservable variables, by 10%, respectively. In the case of interest rate related derivative assets and liabilities, fair value changes are calculated by increasing or decreasing the volatility of interest rate, which are major unobservable variables, by 10%. (*2) Both derivative assets and liabilities for held for trading and hedging are included. (*3) Fair value changes of equity securities are calculated by increasing or decreasing growth rate (0~1%) and discount rate or liquidation value (-1~1%). (*4) Even if the sensitivity analysis of the capital contributions and beneficiary certificates is not possible in practice, fair value changes of beneficiary certificates and other securities whose major unobservable variables are composed of the real estate are calculated by increasing or decreasing price fluctuation of real estate which is underlying assets and discount rate by 1%. (*5) Changes of fair value are measured by increasing or decreasing the discount rate by 10%, which is major unobservable variable, respectively.
Schedule of fair value measurement of financial instruments measured at amortised costs [Table Text Block]	(5) Fair value and carrying amount of financial assets and liabilities that are recorded at amortized cost are as follows (Unit: Korean Won in millions): June 30, 2018 Fair value Book Level 1 Level 2 Level 3 Total Financial assets: Securities at amortized cost 1,792,215 15,911,262 — 17,703,477 17,702,129 Loans and other financial assets at amortized cost — — 277,718,440 277,718,440 277,720,003 Financial liabilities: Deposits due to customers — 237,811,780 — 237,811,780 237,900,166 Borrowings — 15,924,417 — 15,924,417 15,899,599 Debentures — 26,586,897 — 26,586,897 26,752,725 Other financial liabilities — 21,405,921 — 21,405,921 21,408,267 December 31, 2017 Fair value Book Level 1 Level 2 Level 3 Total Financial assets: HTM financial assets 1,206,292 15,509,387 — 16,715,679 16,749,296 Loans and receivables — — 265,570,649 265,570,649 267,106,204 Financial liabilities: Deposits due to customers — 234,682,775 — 234,682,775 234,695,084 Borrowings — 14,754,506 — 14,754,506 14,784,706 Debentures — 27,889,781 — 27,889,781 27,869,651 Other financial liabilities — 13,890,789 — 13,890,789 13,892,461
Valuation techniques and inputs used in fair value measurement of financial instruments measured at amortised costs [Table Text Block]	The fair values of financial instruments are measured using quoted market price in active markets. In case there is no active market for financial instruments, the Group determines the fair value using valuation methods. Valuation methods and input variables for financial assets and liabilities that are measured at amortized costs are given as follows: Valuation methods Input variables Securities at amortized cost (HTM financial assets in previous year) The fair value is measured by discounting the projected cash flows of debt securities by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the issuers of the securities. Risk-free market rate Loans and other financial assets at amortized cost (Loans and receivables in previous year) The fair value is measured by discounting the projected cash flows of loan products by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the debtor. Risk-free market rate, credit spread and prepayment-rate Deposits due to customers, borrowings, debentures and other financial liabilities The fair value is measured by discounting the projected cash flows of debt products by applying the market discount rate that is reflecting credit rating of the Group. Risk-free market rate and forward rate
Disclosure of categories of financial assets	Carrying amounts of financial assets and liabilities are as follows (Unit: Korean Won in millions): June 30, 2018 Financial assets Financial asset Financial assets Financial assets at Derivatives Total Deposits 24,921 — 17,770,356 — 17,795,277 Securities at fair value through profit or loss 3,587,605 — — — 3,587,605 Securities at FVTOCI — 14,644,608 — — 14,644,608 Securities at amortized cost — — 17,702,129 — 17,702,129 Loans 336,967 — 248,794,014 — 249,130,981 Derivative assets 2,391,211 — — 12,395 2,403,606 Other financial assets at amortized cost — — 11,155,633 — 11,155,633 Total 6,340,704 14,644,608 295,422,132 12,395 316,419,839 December 31, 2017 Financial assets Financial assets AFS financial HTM financial Loans Derivatives Total Deposits 25,972 — — 8,868,378 — 8,894,350 Financial assets at FVTPL 2,701,330 — — — — 2,701,330 AFS financial assets — 15,352,950 — — — 15,352,950 HTM financial assets — — 16,749,296 — — 16,749,296 Loans — — — 251,523,301 — 251,523,301 Derivative assets 3,115,775 — — — 59,272 3,175,047 Other financial assets at amortized cost — — — 6,714,525 — 6,714,525 Total 5,843,077 15,352,950 16,749,296 267,106,204 59,272 305,110,799
Disclosure of categories of financial liabilities	Carrying amounts of financial assets and liabilities are as follows (Unit: Korean Won in millions): Financial liabilities June 30, 2018 Financial liabilities Financial liabilities Derivatives Total Deposits due to customers 24,485 237,900,166 — 237,924,651 Borrowings 176,097 15,899,599 — 16,075,696 Debentures — 26,752,725 — 26,752,725 Derivative liabilities 2,377,750 — 67,505 2,445,255 Other financial liabilities (*) — 21,463,163 — 21,463,163 Total 2,578,332 302,015,653 67,505 304,661,490 (*) Other financial liabilities include 54,896 million Won of financial guarantee liabilities measured at amortized cost included in provisions (Note 23). Financial liabilities June 30, 2017 Financial liabilities Financial liabilities Derivatives Total Deposits due to customers 25,964 234,695,084 — 234,721,048 Borrowings 160,057 14,784,706 — 14,944,763 Debentures 91,739 27,869,651 — 27,961,390 Derivative liabilities 3,150,149 — 67,754 3,217,903 Other financial liabilities (*) — 13,964,158 — 13,964,158 Total 3,427,909 291,313,599 67,754 294,809,262 (*) Other financial liabilities include 71,697 million Won of financial guarantee liabilities measured at amortized cost included in provisions (Note 23).

Derecognition and offset of f64

Derecognition and offset of financial instruments (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of derecognition and offsetting of financial assets and liabilities [Abstract]
Transferred financial assets of securities under repurchase agreement that are not derecognized in their entirety	a) Disposal of securities under repurchase agreements The financial instruments that were disposed but the Group agreed to repurchase at the fixed amounts at the same time, so that they did not meet the conditions of derecognition, are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Assets transferred Financial assets at FVTOCI 10,002 — AFS financial assets — 9,998 Securities at amortized cost 5,444 — HTM financial assets — 5,436 Total 15,446 15,434 Related liabilities Bonds sold under repurchase agreements 5,372 3,173
Transferred financial assets of loaned securities that are not derecognized in their entirety	b) Securities loaned When the Group loans its securities to outside parties, the legal ownerships of the securities are transferred; however, they should be returned at the end of lending period. Therefore, the Group does not derecognize them from the financial statements as it owns majority of risks and benefits from the securities continuously, regardless of the transfer of legal ownership. The carrying amounts of the securities loaned are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Loaned to Financial assets at FVTOCI Korean treasury, corporation bonds and others 50,139 — Korea Securities AFS financial assets Korean treasury, government bonds and others — 170,256 Korea Securities Total 50,139 170,256
Financial instruments subject to offset enforceable master netting agreements or similar agreements	As of June 30, 2018 and December 31, 2017, the financial instruments to be off set and may be covered by master netting agreements and similar agreements are as follows (Unit: Korean Won in millions): June 30, 2018 Gross Gross Net Related amounts not set off Net Netting Cash Financial assets: Derivative assets and others (*1) 2,132,698 — 2,132,698 8,716,272 21,543 857,980 Receivable spot exchange (*2) 7,463,097 — 7,463,097 Bonds purchased under resale agreements (*2) 6,999,881 — 6,999,881 6,999,881 — — Domestic exchanges receivable (*2)(*5) 27,527,610 27,338,204 189,406 — — 189,406 Total 44,123,286 27,338,204 16,785,082 15,716,153 21,543 1,047,386 June 30, 2018 Gross Gross Net Related amounts not set off Net Netting Cash Financial liabilities: Derivative liabilities and others (*1) 2,305,516 — 2,305,516 8,704,614 208,955 856,626 Payable spot exchange (*3) 7,464,679 — 7,464,679 Bonds sold under repurchase agreements (*4) 5,372 — 5,372 5,372 — — Domestic exchanges payable (*3)(*5) 31,538,065 27,338,204 4,199,861 3,408,953 — 790,908 Total 41,313,632 27,338,204 13,975,428 12,118,939 208,955 1,647,534 (*1) The items include derivatives held for trading, derivatives held for hedging and equity-linked securities. (*2) The items are included in loan at amortized cost and other financial assets. (*3) The items are included in other financial liabilities. (*4) The items are included in borrowings. (*5) Certain financial assets and liabilities are presented as net amounts. December 31, 2017 Gross Gross Net Related amounts not set off in Net Netting Cash Financial assets: Derivative assets and others (*1) 2,992,476 1,710 2,990,766 5,787,448 174,415 796,629 Receivable spot exchange (*2) 3,767,726 — 3,767,726 Bonds purchased under resale agreements (*2) 16,859,064 — 16,859,064 16,859,064 — — Domestic exchanges receivable (*2)(*5) 39,050,227 38,985,354 64,873 — — 64,873 Total 62,669,493 38,987,064 23,682,429 22,646,512 174,415 861,502 December 31, 2017 Gross Gross Net Related amounts not set off in Net Netting Cash Financial liabilities: Derivative liabilities and others (*1) 3,160,217 1,710 3,158,507 5,866,682 157,750 857,961 Payable spot exchange (*3) 3,723,886 — 3,723,886 Bonds sold under repurchase agreements (*4) 3,173 — 3,173 3,173 — — Domestic exchanges payable (*3)(*5) 40,284,515 38,985,354 1,299,161 1,293,931 — 5,230 Total 47,171,791 38,987,064 8,184,727 7,163,786 157,750 863,191 (*1) The items include derivatives held for trading, derivatives for hedging and equity linked securities. (*2) The items are included in loans and receivables. (*3) The items are included in other financial liabilities. (*4) The items are included in borrowings. (*5) Certain financial assets and liabilities are presented at as net amounts.

Investment in Joint Ventures 65

Investment in Joint Ventures and Associates (Tables)	6 Months Ended
	Jun. 30, 2018
Equity Method Investments And Joint Ventures [Abstract]
Schedule of investments in associates and joint ventures accounted for using equity method [Table Text Block]	(1) Investments in joint ventures and associates accounted for using the equity method of accounting are as follows (Unit: Korean Won in millions): Percentage of Financial Joint ventures and Associates Main business June 30, December 31, Woori Bank: Kumho Tire Co., Inc. (*1)(*2) Manufacturing 14.2 14.2 March 31 (*3) Woori Service Networks Co., Ltd. (*4) Freight & staffing services 4.9 4.9 May 31 (*3) Korea Credit Bureau Co., Ltd. (*5) Credit information 9.9 9.9 June 30 Korea Finance Security Co., Ltd. (*4) Security service 15.0 15.0 May 31 (*3) Chin Hung International Inc. (*2) Construction 25.3 25.3 May 31 (*3) Poonglim Industrial Co., Ltd. (*6)(*9) Construction — 29.4 — STX Engine Co., Ltd. (*10) Manufacturing — 29.2 — STX Corporation (*1)(*11) Wholesale of non-specialized 19.7 19.7 May 31 (*3) Saman Corporation (*5) General construction Technology service 9.2 9.2 May 31 (*3) Dongwoo C & C Co., Ltd. (*6) Construction 23.2 23.2 — SJCO Co., Ltd. (*6) Aggregate transportation and wholesale 26.5 26.5 — G2 Collection Co., Ltd. (*6) Wholesale and retail sales 28.9 28.9 — The Base Enterprise Co., Ltd. (*6) Manufacturing 48.4 48.4 — Kyesan Engineering Co., Ltd. (*6) Construction 23.2 23.2 — Good Software Lap Co., Ltd. (*6) Service 28.9 28.9 — Wongwang Co., Ltd. (*6) Wholesale and real estate 29.0 29.0 — Sejin Construction Co., Ltd. (*6) Construction 29.6 29.6 — QTS Shipping Co., Ltd. (*6) Composite transportation Arrangement 49.4 49.4 — DAEA SNC Co., Ltd. (*6) Wholesale and retail sales 24.0 24.0 ARES-TECH Co., Ltd. (*6) Electronic component manufacturing 23.4 23.4 — Reading Doctors Co., Ltd. (*6) Other service business 35.4 35.4 — PREXCO Co., Ltd. (*6) Manufacturing 28.1 28.1 — Hyunwoo International Co., Ltd. (*6) Manufacturing 25.9 25.9 — Jiwon Plating Co., Ltd. (*6) Plating 20.5 20.5 — Cultizm Korea LTD Co., Ltd. (*6) Wholesale and retail sales 31.3 31.3 — Gil Co.,Ltd. (*6) Manufacturing 26.1 26.1 — NK Eng Co., Ltd. (*6) Manufacturing 23.1 23.1 — Youngdong Sea Food Co., Ltd. (*6)(*7) Processed sea food manufacturing 24.0 — — Woori Growth Partnerships New Technology Private Equity Fund Other financial business 23.1 23.1 June 30 2016KIF-IMM Other financial business 20.0 20.0 June 30 K BANK Co., Ltd. (*5) Finance 13.0 13.0 May 31 (*3) Smart Private Equity Fund No.2 Other financial business 20.0 20.0 June 30 Woori Bank-Company K Korea Movie Asset Fund Other financial business 25.0 25.0 June 30 Well to Sea No. 3 Private Equity Fund (*12) Finance 50.0 50.0 March 31 (*3) Partner One Value Up I Private Equity Fund (*8) Other financial business 23.3 — June 30 IBK KIP Seongjang Dideemdol 1st Private Investment Limited Partnership (*8) Other Finance business 20.0 — June 30 Woori Investment Bank Co., Ltd.: Nomura-Rifa Private Real Estate Investment Trust No.17 Other financial business 21.9 25.0 June 30 (*1) The Group has significant influence on these entities through its position in the creditors’ council which is the decision making body regarding to financial and operational policies of associates. (*2) The investments in associates that have quoted market prices are Kumho Tire Co., Ltd. (current period: KRW 6,310, previous year: KRW 4,425), Chin Hung International Inc. (current period: KRW 1,935, previous year: KRW 1,915). (*3) The significant transactions and events between the end of reporting period of the associates and the Group have been properly incorporated. (*4) Most of the significant business transactions of associates are with the Group as of June 30, 2018 and December 31, 2017. (*5) The Group can participate in decision-making body and exercise significant influence over associates through business partnerships. (*6) The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017. (*7) As of December 31, 2017, the ownership ratio of the common stocks was more than 20%, but the entity was excluded from investments in associates because it has been under rehabilitation and not able to exercise significant influence. However, as of June 30, 2018, it was included in investments in associates by finalizing rehabilitation process by the court administration. (*8) Due to capital contribution by the Group for the six months ended June 30, 2018, the entities has been included in the investment in associates. (*9) The Group does not have significant influence over the entity since it is going through work-out (*10) The entity was sold after it was transferred to assets held for sale for the year ended June 30, 2018. (*11) The shares of STX Corporation owned by the Group were reclassified as assets held for sale, as the creditor financial institutions committee entered into a contract with AFC Korea Co., Ltd. during the previous year to sell STX Corporation shares. (*12) The Bank has entered into a contract whereas the Bank (or a third party designated by the Bank) obtains a preemptive right to acquire the base assets (Aju Capital Co. Ltd.) of Well to Sea No. 3 Private Equity Fund, an affiliate of the Bank, when the Fund disposes them.
Schedule of changes in carrying value of investments in associates and joint ventures accounted for using equity method [Table Text Block]	(2) Changes in the carrying value of investments in joint ventures and associates accounted for using the equity method of accounting are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Acquisition January 1, Share of Acquisition Disposal Dividends Change in June 30, Kumho Tire Co., Inc. 175,652 98,933 (10,451 ) — — — (5,196 ) 83,286 Woori Service Networks Co., Ltd. 108 158 (20 ) — — — — 138 Korea Credit Bureau Co., Ltd. 3,313 5,816 692 — — (113 ) — 6,395 Korea Finance Security Co., Ltd. 3,267 3,519 4 — — (54 ) 1 3,470 Chin Hung International Inc. 130,779 45,101 3,179 — — — (484 ) 47,796 Poonglim Industrial Co., Ltd. 13,916 — — — — — — — STX Corporation 50,760 6,947 (816 ) — (5,865 ) — (266 ) — Saman Corporation 8,521 1,254 (48 ) — — — 34 1,240 Woori Growth Partnerships New Technology Private Equity Fund 28,833 27,611 1,139 — (3,346 ) (484 ) — 24,920 2016KIF-IMM 6,840 6,840 — 6,780 — — — 13,620 K BANK Co., Ltd. 45,392 31,735 (5,384 ) — — — 7 26,358 Smart Private Equity Fund No.2 3,000 2,932 (21 ) — — — — 2,911 Woori Bank-Company K Korea Movie Asset Fund 3,000 2,957 10 — — — — 2,967 Well to Sea No.3 Private Equity Fund 101,992 182,309 10,321 — (508 ) — (6,423 ) 185,699 Partner One Value Up I Private Equity Fund 10,000 — (13 ) 10,000 — — — 9,987 IBK KIP Seongjang Dideemdol 1st Private Investment Limited Partnership 3,268 — — 3,268 — — — 3,268 Nomura-Rifa Private Real Estate Investment Trust No.17 1,000 939 (54 ) — — — — 885 Total 589,641 417,051 (1,462 ) 20,048 (9,719 ) (651 ) (12,327 ) 412,940 (*1) Investments in joint ventures and associates decreased by 5,865 million Won through transfers to assets held for sale which occurred during the six months ended June 30, 2018. For the six months ended June 30, 2017 Acquisition January 1, Share of Acquisition Disposal Dividends Change in Others June 30, Woori Blackstone Korea Opportunity No.1 Private Equity Fund 6,881 15,289 (1,460 ) — — — — — 13,829 Kumho Tire Co., Inc. 175,652 200,332 2 — — — (1,623 ) — 198,711 Woori Service Networks Co., Ltd. 108 145 (10 ) — — (8 ) — — 127 Korea Credit Bureau Co., Ltd. 3,313 5,592 508 — — (149 ) — — 5,951 Korea Finance Security Co., Ltd. 3,266 3,376 63 — — (54 ) — — 3,385 Chin Hung International Inc. 89,725 43,032 (20,050 ) 41,053 — — 171 (25,966 ) 38,240 Poonglim Industrial Co., Ltd. 13,916 — — — — — — — — STX Engine Co., Ltd. 92,038 43,036 722 — — — 4,047 — 47,805 SamHo Co., Ltd. 7,492 19,729 2,021 — (16,354 ) — (73 ) (5,323 ) — STX Corporation 42,215 — (33,739 ) 8,546 — — (215 ) 27,772 2,364 Saman Corporation 8,521 8,699 (96 ) — — — 26 — 8,629 Woori Growth Partnerships New Technology Private Equity Fund 13,602 13,118 (371 ) 5,745 (498 ) — (156 ) — 17,838 2016KIF-IMM 1,800 1,800 — 3,240 — — — — 5,040 K BANK Co., Ltd. 32,500 30,442 (5,861 ) — — — (139 ) — 24,442 Smart Private Equity Fund No.2 3,000 — (47 ) 3,000 — — — — 2,953 Woori Bank-Company K Korea Movie Asset Fund 1,500 — (15 ) 1,500 — — — — 1,485 Woori Renaissance Holdings 63,000 54,422 (622 ) — — (57,109 ) — 3,309 — 558,529 439,012 (58,955 ) 63,084 (16,852 ) (57,320 ) 2,038 (208 ) 370,799 (*1) Changes in investments in joint ventures and associates due to debt-equity swap is 51,405 million Won. (*2) Investments in joint ventures and associates decreased by 16,354 million Won through transfers to assets held for sale occurred for the six months ended June 30, 2017.
Reconciliation of summarised financial information of associates and joint ventures accounted for using equity method to carrying amount of interest in associates and joint ventures [Table Text Block]	(3) Summary financial information relating to investments in joint ventures and associates accounted for using the equity method of accounting is as follows (Unit: Korean Won in millions): June 30, 2018 Assets Liabilities Operating Net income Kumho Tire Co., Inc. 4,513,972 3,521,608 624,981 (10,774 ) Woori Service Networks Co., Ltd. 4,909 2,111 7,250 456 Korea Credit Bureau Co., Ltd. 80,792 18,764 37,342 5,919 Korea Finance Security Co., Ltd. 32,635 9,501 27,161 91 Chin Hung International Inc. 403,962 311,502 263,861 19,062 Saman Corporation 89,932 61,583 26,418 (326 ) Woori Growth Partnerships New Technology Private Equity Fund 108,427 441 7,865 4,936 2016KIF-IMM 65,760 383 6 (754 ) K BANK Co., Ltd. 1,758,930 1,557,206 24,296 (32,126 ) Smart Private Equity Fund No.2 14,605 51 1 (106 ) Woori Bank-Company K Korea Movie Asset Fund 11,872 3 893 769 Well to Sea No.3 Private Equity Fund 5,297,764 4,759,158 140,041 13,450 Partner One Value Up I Private Equity Fund 43,114 172 114 (58 ) IBK KIP Seongjang Dideemdol 1st Private Investment Limited Partnership 15,843 744 4 (822 ) Nomura-Rifa Private Real Estate Investment Trust No.17 20,433 16,407 56 (55 ) December 31, 2017 Assets Liabilities Operating Net income Kumho Tire Co., Inc. 5,105,107 3,928,327 2,136,569 (61,748 ) Woori Service Networks Co., Ltd. 4,982 1,780 14,887 1,003 Korea Credit Bureau Co., Ltd. 75,504 19,323 68,750 3,580 Korea Finance Security Co., Ltd. 33,915 10,461 55,610 1,071 Chin Hung International Inc. 341,284 259,454 513,285 28,698 Poonglim Industrial Co., Ltd. 241,063 309,925 107,360 (29,812 ) STX Corporation 595,348 543,458 1,371,272 342,869 Saman Corporation 98,435 69,929 76,135 (6,096 ) Woori Growth Partnerships New Technology Private Equity Fund 120,133 485 1,024 (3,199 ) 2016KIF-IMM 32,815 380 6 (1,515 ) K BANK Co., Ltd. 1,244,270 1,001,121 19,231 (74,403 ) Smart Private Equity Fund No.2 14,711 51 1 (340 ) Woori Bank-Company K Korea Movie Asset Fund 11,830 2 16 (172 ) Well to Sea No.3 Private Equity Fund 5,068,424 4,534,957 131,488 162,743 Nomura-Rifa Private Real Estate Investment Trust No.17 20,265 16,507 62 (242 )
Schedule of investments that were not accounted for using equity method [Table Text Block]	(4) The entities that the Group has not applied equity method of accounting although the Group’s ownership interest is more than 20% as of June 30, 2018 and December 31, 2017 are as follows: June 30, 2018 Associate (*) Number of shares owned Ownership (%) Poonglim Industrial Co., Ltd. 4,142,782 29.1 Orient Shipyard Co., Ltd. 464,812 21.4 Saenuel Co., Ltd. 3,531 37.4 E Mirae Tech Co., Ltd. 7,696 41.0 Jehin Trading Co., Ltd. 81,610 27.3 The season Co., Ltd. 18,187 30.1 Yuil PESC Co., Ltd. 8,642 24.0 Sinseong Trading Co., Ltd. 2,584 27.2 CL Tech Co., Ltd. 13,759 38.6 Force TEC Co., Ltd. 4,780,907 25.8 Protronics Co., Ltd. 95,921 48.1 Instern Co., Ltd. 14,296 20.1 (*) Even though the Group’s ownership interest of the entity is more than 20%, the Group does not have significant influence over the entity since it is going through work-out As of December 31, 2017 Associate (*) Number of shares owned Ownership (%) Orient Shipyard Co., Ltd. 465,050 21.4 Saenuel Co., Ltd. 3,531 37.4 E Mirae Tech Co., Ltd. 7,696 41.0 Jehin Trading Co., Ltd. 81,610 27.3 The season Co., Ltd. 18,187 30.1 Yuil PESC Co., Ltd. 8,642 24.0 Youngdong Sea Food Co., Ltd. 12,106 24.0 Sinseong Trading Co., Ltd. 2,584 27.2 CL Tech Co., Ltd. 13,759 38.6 Force TEC Co., Ltd. 4,780,907 25.8 Protronics Co., Ltd. 95,921 48.1 Instern Co., Ltd. 14,296 20.1 (*) Even though the Group’s ownership interest of the entity is more than 20%, the Group does not have significant influence over the entity since it is going through work-out
Reconciliation from net assets of investments in associates and joint ventures accounted for using equity method to book value [Table Text Block]	(5) As of June 30, 2018 and December 31, 2017, the reconciliations from the net assets of associates based on the ownership ratio of the Group to its corresponding book value of investment in joint ventures and associates are as follows (Unit: Korean Won in millions except for ownership): June 30, 2018 Total net Ownership Ownership Cost-book Impairment Intercompany Book Kumho Tire Co., Inc. (*) 954,857 14.2 135,122 48,459 (102,843 ) 2,548 83,286 Woori Service Networks Co., Ltd. 2,798 4.9 138 — — — 138 Korea Credit Bureau Co., Ltd. 62,028 9.9 6,149 246 — — 6,395 Korea Finance Security Co., Ltd. 23,134 15.0 3,470 — — — 3,470 Chin Hung International Inc. (*) 92,316 25.3 23,361 24,565 — (130 ) 47,796 Saman Corporation 28,349 9.2 2,605 5,373 (6,738 ) — 1,240 Woori Growth Partnerships New Technology Private Equity Fund 107,986 23.1 24,920 — — — 24,920 2016KIF-IMM 65,377 20.0 13,075 — — 545 13,620 K BANK Co., Ltd. 201,724 13.0 26,162 — — 196 26,358 Smart Private Equity Fund No.2 14,554 20.0 2,911 — — — 2,911 Woori Bank-Company K Korea Movie Asset Fund 11,869 25.0 2,967 — — — 2,967 Well to Sea No.3 Private Equity Fund (*) 371,813 50.0 185,816 — — (117 ) 185,699 Partner One Value Up I Private Equity Fund 42,942 23.3 9,987 — — — 9,987 IBK KIP Seongjang Dideemdol 1st Private Investment Limited Partnership 15,099 20.0 3,020 — — 248 3,268 Nomura-Rifa Private Real Estate Investment Trust No.17 4,026 21.9 882 — — 3 885 (*) The net asset amount is after reflecting debt-equity swap and others. December 31, 2017 Total net Ownership Ownership Cost-book Impairment Intercompany Book Kumho Tire Co., Inc. (*) 1,065,421 14.2 150,767 48,459 (102,843 ) 2,550 98,933 Woori Service Networks Co., Ltd. 3,202 4.9 158 — — — 158 Korea Credit Bureau Co., Ltd. 56,181 9.9 5,568 248 — — 5,816 Korea Finance Security Co., Ltd. 23,454 15.0 3,519 — — — 3,519 Chin Hung International Inc. (*) 81,686 25.3 20,671 24,565 — (135 ) 45,101 Poonglim Industrial Co., Ltd. (*) (168,154 ) 29.4 (49,446 ) 54,542 (20,504 ) 15,408 — STX Corporation 51,890 19.7 10,232 24,614 (27,904 ) 5 6,947 Saman Corporation 28,506 9.2 2,619 5,373 (6,738 ) — 1,254 Woori Growth Partnerships New Technology Private Equity Fund 119,648 23.1 27,611 — — — 27,611 2016KIF-IMM 32,435 20.0 6,487 — — 353 6,840 K BANK Co., Ltd. 243,149 13.0 31,535 — — 200 31,735 Smart Private Equity Fund No.2 14,660 20.0 2,932 — — — 2,932 Woori Bank-Company K Korea Movie Asset Fund 11,828 25.0 2,957 — — — 2,957 Well to Sea No.3 Private Equity Fund (*) 364,909 50.0 182,366 — — (57 ) 182,309 Nomura-Rifa Private Real Estate Investment Trust No.17 3,758 25.0 939 — — — 939 (*) The net asset amount is after reflecting debt-equity swap and others.

Investment Properties (Tables)

Investment Properties (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure Of Investment Property [Abstract]
Details of investment properties	(1) Details of investment properties are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Acquisition cost 417,692 404,741 Accumulated depreciation (36,515 ) (33,440 ) Net carrying value 381,177 371,301
Changes in investment properties	(2) Changes in investment properties are as follows (Unit: Korean Won in millions): For the six months ended June 30 2018 2017 Beginning balance 371,301 358,497 Acquisition 7,311 1,221 Disposal (1,738 ) (225 ) Depreciation (2,010 ) (1,991 ) Transfers 6,333 (2,708 ) Classified to held for sale — (534 ) Foreign currencies translation adjustments (79 ) (120 ) Others 59 5,797 Ending balance 381,177 359,937

Premises and Equipment (Tables)

Premises and Equipment (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure Of Property Plant And Equipment [Abstract]
Carrying value of property plant and equipment	(1) Details of premises and equipment are as follows (Unit: Korean Won in millions): June 30, 2018 Land Building Properties for Structures in Construction Structures Total Acquisition cost 1,482,169 863,503 1,105,029 441,835 4,421 20 3,896,977 Accumulated depreciation — (197,688 ) (868,768 ) (379,750 ) — (17 ) (1,446,223 ) Net carrying value 1,482,169 665,815 236,261 62,085 4,421 3 2,450,754 December 31, 2017 Land Building Properties for Structures in Construction Structures Total Acquisition cost 1,487,278 867,804 1,024,186 429,665 64,559 20 3,873,512 Accumulated depreciation — (186,958 ) (844,114 ) (364,878 ) — (17 ) (1,395,967 ) Net carrying value 1,487,278 680,846 180,072 64,787 64,559 3 2,477,545
Changes in premises and equipment	(2) Details of changes in premises and equipment are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Land Building Properties for Structures in Construction Structures Total Beginning balance 1,487,278 680,846 180,072 64,787 64,559 3 2,477,545 Acquisitions 463 4,326 27,635 6,928 3,342 — 42,694 Disposals — — (72 ) (89 ) — — (161 ) Depreciation — (12,960 ) (36,144 ) (17,696 ) — — (66,800 ) Classified to held for sale (3,573 ) (2,477 ) — — — — (6,050 ) Transfer (1,910 ) (4,423 ) 63,433 — (63,433 ) — (6,333 ) Foreign currencies translation adjustments (89 ) (121 ) 352 489 (47 ) — 584 Acquisition through business combination — — 969 661 — — 1,630 Others — 624 16 7,005 — — 7,645 Ending balance 1,482,169 665,815 236,261 62,085 4,421 3 2,450,754 For the six months ended June 30, 2017 Land Building Properties for Structures in Construction Structures Total Beginning balance 1,488,745 691,699 189,902 68,958 18,717 4 2,458,025 Acquisitions — 3,831 31,624 8,120 25,053 — 68,628 Disposals (606 ) (205 ) (235 ) (423 ) — — (1,469 ) Depreciation — (13,029 ) (38,063 ) (18,253 ) — (1 ) (69,346 ) Classified to assets held for sale (1,743 ) (441 ) — — — — (2,184 ) Transfer 2,466 403 5,485 — (5,646 ) — 2,708 Foreign currencies translation adjustments (596 ) (560 ) (676 ) (675 ) (247 ) — (2,754 ) Others — (6 ) 188 5,386 — — 5,568 Ending balance 1,488,266 681,692 188,225 63,113 37,877 3 2,459,176

Intangible assets (Tables)

Intangible assets (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure Of Intangible Assets [Abstract]
Carrying value of intangible assets and goodwill	(1) Details of intangible assets are as follows (Unit: Korean Won in millions): June 30, 2018 Goodwill Software Industrial Development Others Membership Construction Total Acquisition cost 154,644 208,383 1,180 463,361 717,332 26,087 8,978 1,579,965 Accumulated amortization — (170,700 ) (611 ) (199,179 ) (550,996 ) — — (921,486 ) Accumulated impairment losses — — — — (137 ) (4,828 ) — (4,965 ) Net carrying value 154,644 37,683 569 264,182 166,199 21,259 8,978 653,514 December 31, 2017 Goodwill Software Industrial Development Others Membership Construction Total Acquisition cost 108,707 203,418 1,063 260,087 634,150 27,337 153,209 1,387,971 Accumulated amortization — (162,746 ) (524 ) (182,846 ) (516,467 ) — — (862,583 ) Accumulated impairment losses — — — — (137 ) (6,652 ) — (6,789 ) Net carrying value 108,707 40,672 539 77,241 117,546 20,685 153,209 518,599
Changes in intangible assets	(2) Details of changes in intangible assets are as follows (Unit: Korean Won in millions): June 30, 2018 Goodwill Software Industrial Development Others Membership Construction Total Beginning balance 108,707 40,672 539 77,241 117,546 20,685 153,209 518,599 Acquisitions — 3,737 117 21,455 36,191 2,311 84,318 148,129 Disposal — — — — — (2,107 ) — (2,107 ) Amortization (*) — (7,510 ) (87 ) (16,317 ) (34,162 ) — — (58,076 ) Reversal of impairment loss — — — — — 339 — 339 Transfer — — — 181,803 46,746 — (228,549 ) — Acquisition through business combination 47,406 763 — — — — — 48,169 Foreign currencies translation adjustment (1,469 ) 21 — — 243 74 — (1,131 ) Others — — — — (365 ) (43 ) — (408 ) Ending balance 154,644 37,683 569 264,182 166,199 21,259 8,978 653,514 (*) Amortization of other intangible assets amounting to 25,179 million Won is included in other operating expenses. June 30, 2017 Goodwill Software Industrial Development Others Membership Construction Total Beginning balance 124,803 35,477 313 70,697 164,364 20,086 67,999 483,739 Acquisitions 105 10,152 54 12,628 10,276 480 55,984 89,679 Disposal — — — — — (866 ) — (866 ) Amortization (*) — (8,064 ) (56 ) (11,515 ) (30,389 ) — — (50,024 ) Impairment loss — — — — — (128 ) — (128 ) Transfer — 8,091 — — 36 — (8,127 ) — Foreign currencies translation adjustment (7,479 ) (68 ) — — (1,053 ) (81 ) (383 ) (9,064 ) Others — (22 ) — (55 ) (6,371 ) (6 ) — (6,454 ) Ending balance 117,429 45,566 311 71,755 136,863 19,485 115,473 506,882 (*) Amortization of other intangible assets amounting to 24,443 million Won is included in other operating expenses.

Assets Held for sale (Tables)

Assets Held for sale (Tables)	6 Months Ended
	Jun. 30, 2018
Non-current assets or disposal groups classified as held for sale or as held for distribution to owners [Abstract]
Details of assets held for sale	Assets held for sale are as follows (Unit: Korean Won in millions): June 30, December 31, Investments in joint ventures and associates 5,865 46,217 Premises and equipment, etc (*) 12,840 2,407 Total 18,705 48,624 (*) As of June 30, 2018 and December 31, 2017, non-operating

Assets Subject to Lien and As70

Assets Subject to Lien and Assets Acquired Through Foreclosures (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure Of Collateral [Abstract]
Assets subjected to lien	(1) Assets subjected to lien are as follows (Unit: Korean Won in millions): June 30, 2018 Collateral given to Amount Reason for collateral Loan at amortized cost and other financial assets Due from banks on time in local currency DaishinAMC and others 1,500 Right of pledge Due from banks in local currencies Samsung Securities Co., Ltd. and others 19,698 Margin deposit for futures or option Due from banks in foreign currencies Korea Investment & Securities Co., Ltd. and others 135,515 Foreign margin deposit for future or option and others Financial assets at FVTPL Korean financial institutions’ debt securities and others Kyobo Life Insurance Co., Ltd. and others 72,915 CSA collateral and others Financial assets at FVTOCI Korean treasury and corporate bonds Korea Securities Depository 10,002 Related to bonds sold under repurchase agreements (*) Korean treasury and government bonds and others The BOK and others 1,621,221 Settlement risk and others Securities at amortized cost Korean treasury and government bonds Korea Securities Depository 5,444 Related to bonds sold under repurchase agreements (*) Korean treasury and government bonds and others The BOK and others 4,908,149 Settlement risk and others Premises and equipment Land and building Credit Counselling & Recovery Service and others 6,065 Right to collateral and others Total 6,780,509 (*) The Group has the agreements to repurchase the sold assets at the predetermined price or the price that includes the rate of return and to provide the guarantee on the assets. The transferee has the right to sell or to provide as guarantee. Therefore, the Group does not derecognize the assets, but recognizes the relevant amounts as liability (bonds sold under repurchase agreements). December 31, 2017 Collateral given to Amount Reason for collateral Loan and receivables Due from banks on time in local currency Bank of China and others 6,629 Collaterals for issuing letter of guarantee and others Due from banks in local currencies Samsung Securities Co., Ltd. and others 10,809 Margin deposit for futures or option Due from banks in foreign currencies Korea Investment & Securities Co., Ltd. and others 9,136 Foreign margin deposit for future or option and others Financial assets at FVTPL Korean financial institutions’ debt securities and others Yuanta Securities Co., Ltd. and others 501,523 Substitute securities and others AFS financial assets Korean treasury and corporate bonds Korea Securities Depository and others 9,998 Related to bonds sold under repurchase agreements (*) Korean treasury and government bonds and others The BOK and others 1,570,608 Settlement risk and others HTM financial assets Korean treasury and government bonds Korea Securities Depository 5,436 Related to bonds sold under repurchase agreements (*) Korean financial institutions’ debt securities and others The BOK and others 7,605,292 Settlement risk and others Premises and equipment Land and building Credit Counselling & Recovery Service and others 6,186 Leasehold rights and others Total 9,725,617 (*) The Group has the agreements to repurchase the sold assets at the predetermined price or the price that includes the rate of return and to provide the guarantee on the assets. The transferee has the right to sell or to provide as guarantee. Therefore, the Group does not derecognize the assets, but recognizes the relevant amounts as liability (bonds sold under repurchase agreements).
Assets acquired through foreclosure [Table Text Block]	(2) The carrying amounts of assets acquired through foreclosure are as follows. (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Land 327 332 Buildings — 44 Total 327 376
Schedule of securities lent [Table Text Block]	(3) Securities loaned are as follows (Unit: Korean Won in millions): June 30, December 31, Loaned to Financial assets at FVTOCI Korean treasury, corporate bonds and others 50,139 — Korea Securities Finance Corporation AFS financial assets Korean treasury, government bonds and others — 170,256 Korea Securities Finance Corporation and others Total 50,139 170,256
Collaterals held that can be disposed and re collateralized regardless of defaults of counterparties	(4) Collaterals held that can be disposed and re-subjected Fair values of collaterals held that can be disposed and re-subjected June 30, 2018 Fair values of collaterals Fair values of collaterals were disposed or re-subjected to lien Securities 7,303,137 — December 31, 2017 Fair values of collaterals Fair values of collaterals were disposed or re-subjected to lien Securities 17,671,490 —

Other Assets (Tables)

Other Assets (Tables)	6 Months Ended
	Jun. 30, 2018
Miscellaneous assets [Abstract]
Details of other assets	Details of other assets are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Prepaid expenses 165,150 130,245 Advance payments 24,879 18,363 Non-operative 327 376 Others 12,444 9,420 Total 202,800 158,404

Financial Liabilitiy at Fair 72

Financial Liabilitiy at Fair Value Through Profit or Loss (Tables)	6 Months Ended
	Jun. 30, 2018
Financial liabilities at fair value through profit or loss [Abstract]
Details of financial liabilities at fair value through profit or loss	(1) Financial liabilities at FVTPL are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Financial liabilities at fair value through profit or loss mandatorily measured at fair value 2,402,235 — Financial liabilities held for trading — 3,176,113 Financial liabilities at fair value through profit or loss designated as upon initial recognition 176,097 — Financial liabilities designated as at FVTPL — 251,796 Total 2,578,332 3,427,909
Details of financial liabilities at fair value through profit or loss mandatorily measured at fair value and financial liabilities held for trading	(2) Financial liabilities at fair value through profit or loss mandatorily measured at fair value(Financial liabilities held for trading) are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Deposits Gold banking liabilities 24,485 25,964 Derivative liabilities 2,377,750 3,150,149 Total 2,402,235 3,176,113
Details of financial liabilities at fair value through profit or loss designated as upon initial recognition and financial liabilities designated at fair value through profit or loss	(3) Financial liabilities at fair value through profit or loss designated as upon initial recognition(Financial liabilities designated as at FVTPL) are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Equity linked securities index: Equity linked securities index in short position 176,097 160,057 Debentures: Debentures in local currency — 91,739 Total 176,097 251,796 Financial liabilities at fair value through profit or loss designated are designated as such in order to eliminate or significantly reduce accounting mismatch arising from recognition or measurement.
Credit risk adjustments to financial liabilities designated at fair value through profit or loss	(4) Credit risk adjustments to financial liabilities at fair value through profit or loss designated as upon initial recognition(Financial liabilities designated as at FVTPL) are as follows (Unit: Korean Won in millions): For the six months For the six months Financial liabilities at fair value through profit or loss designated as upon initial recognition 176,097 — Financial liabilities designated as at FVTPL — 616,177 Changes in fair value for credit risk adjustments (179 ) (261 ) Accumulated changes in credit risk adjustments (39 ) 89
Differences between financial liabilities at fair value through profit or loss carrying amount and nominal amount at maturity	(5) The difference between financial liabilities at fair value through profit or loss designated as upon initial recognition’s(Financial liabilities designated as at FVTPL) carrying amount and nominal amount at maturity is as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Carrying amount 176,097 251,796 Nominal amount at maturity 212,259 255,408 Difference (36,162 ) (3,612 )
Changes in equity in relation to financial liabilities at FVTPL designated upon initial recognition cumulative gains	2) Cumulative gains on financial liabilities designated at FVTPL replaced to retained earnings from other comprehensive income are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Equity-linked securities index: (8 )

Deposits Due to Customers (Tabl

Deposits Due to Customers (Tables)	6 Months Ended
	Jun. 30, 2018
Deposits from customers [Abstract]
Details of deposits sorted by interest type	Details of deposits due to customers by type are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Deposits in local currency: Deposits on demand 9,337,563 9,349,070 Deposits at termination 198,768,356 194,292,679 Mutual installment 32,292 34,055 Deposits on notes payables 1,705,871 1,323,679 Deposits on CMA 154,782 164,431 Certificate of deposits 4,592,575 4,436,443 Other deposits 1,401,853 1,451,841 Subtotal 215,993,292 211,052,198 Deposits in foreign currency: Deposits in foreign currencies 21,950,041 23,682,896 Present value discount (43,167 ) (40,010 ) Total 237,900,166 234,695,084

Borrowings and Debentures (Tabl

Borrowings and Debentures (Tables)	6 Months Ended
	Jun. 30, 2018
Borrowings [Abstract]
Details of borrowings	(1) Details of borrowings are as follows (Unit: Korean Won in millions): June 30, 2018 Lenders Interest rate (%) Amount Borrowings in local currency: Borrowings from The BOK The BOK 0.5 ~ 0.8 1,420,990 Borrowings from government funds Small Enterprise And Market Service and others 0.0 ~ 2.5 1,782,603 Others The Korea Development Bank and others 0.0 ~ 4.0 4,665,845 Subtotal 7,869,438 Borrowings in foreign currencies: Borrowings in foreign currencies The Export-Import 0.0 ~ 6.5 7,148,402 Offshore borrowings in foreign currencies JPMORGAN CHASE BANK 2.8 33,651 Subtotal 7,182,053 Bills sold Others 0.0 ~ 1.2 23,874 Call money Bank and others 0.0 ~ 6.3 818,889 Bonds sold under repurchase agreements Other financial institutions 0.7 ~ 12.7 5,372 Present value discount (27 ) Total 15,899,599 December 31, 2017 Lenders Interest rate (%) Amount Borrowings in local currency: Borrowings from The BOK The BOK 0.5 ~ 0.8 1,404,087 Borrowings from government funds Small Enterprise And Market Service and others 0.0 ~ 2.9 1,723,340 Others The Korea Development Bank and others 0.0 ~ 3.2 3,957,421 Subtotal 7,084,848 Borrowings in foreign currencies: Borrowings in foreign currencies The Export-Import 0.0 ~ 6.8 6,996,551 Offshore borrowings in foreign currencies Commonwealth Bank 1.8 28,285 Subtotal 7,024,836 Bills sold Others 0.0 ~ 1.2 36,953 Call money Bank and others 1.5 ~ 2.7 635,061 Bonds sold under repurchase agreements Other financial institutions 0.6 ~ 12.7 3,173 Present value discount (165 ) Total 14,784,706
Schedule of debentures [Table Text Block]	(2) Details of debentures are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Interest rate Amount Interest rate Amount Face value of bond(*): Ordinary bonds 1.5 ~ 4.5 21,105,565 1.5 ~ 5.8 22,468,908 Subordinated bonds 3.0 ~ 12.6 5,006,632 3.4 ~ 12.6 4,781,301 Other bonds 1.9 ~ 17.0 676,144 1.6 ~ 17.0 649,615 Subtotal 26,788,341 27,899,824 Discounts on bonds (35,616 ) (30,173 ) Total 26,752,725 27,869,651 (*) Included debentures under fair value hedge relationships are 3,150,145 million Won and 3,089,751 million Won as of June 30, 2018 and December 31, 2017, respectively. Also, debentures under cash flow hedge amounting to 724,487 million Won and 694,548 million Won are included as of June 30, 2018 and December 31, 2017.

Provisions (Tables)

Provisions (Tables)	6 Months Ended
	Jun. 30, 2018
Provisions [Abstract]
Details of provisions	(1) Details of provisions are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Asset retirement obligation 67,458 61,872 Provisions for guarantees (*1) 106,827 183,247 Provisions for unused commitments 101,874 66,115 Provisions for customer reward credits 46,735 40,445 Other provisions (*2) 63,480 58,791 Total 386,374 410,470 (*1) Provisions for guarantees includes provision for financial guarantee of 54,896 million Won and 71,697 million Won as of June 30, 2018 and December 31, 2017, respectively. (*2) Other provisions consist of provision for litigation and others.
Changes in provisions on guarantee	1) Provisions for guarantees For the six months ended June 30, 2018 Stage1 Stage2 Stage3 Total Beginning balance (*) 47,132 18,281 127,511 192,924 Replaced by 12-month 76 (76 ) — — Replaced with expected credit loss for the entire period (954 ) 58,894 (57,940 ) — Replaced with credit-impaired financial assets (21 ) (20 ) 41 — Provisions used (8,506 ) — — (8,506 ) Net reversal of unused amount (4,873 ) (46,344 ) (35,773 ) (86,990 ) Others 9,393 6 — 9,399 Ending balance 42,247 30,741 33,839 106,827 (*) The beginning balance was restated in accordance with IFRS 9. For the six months ended Beginning balance 238,117 Provisions provided 1,003 Provisions used (12,335 ) Reversal of provisions unused (45,971 ) Foreign currencies translation adjustments 20 Others 7,920 Ending balance 188,754
Changes in provisions on loan commitments	2) Provisions for unused commitment For the six months ended June 30, 2018 Stage1 Stage2 Stage3 Total Beginning balance (*) 75,232 27,875 1,878 104,985 Replaced by 12-month 6,262 (6,145 ) (117 ) — Replaced with expected credit loss for the entire period (2,543 ) 2,614 (71 ) — Replaced with credit-impaired financial assets (159 ) (325 ) 484 — Net provision(reversal) of unused amount (6,183 ) 3,356 (328 ) (3,155 ) Others 44 — — 44 Ending balance 72,653 27,375 1,846 101,874 (*) The beginning balance was restated in accordance with IFRS 9. For the six months ended Beginning balance 87,909 Provisions provided 491 Provisions used (42 ) Reversal of provisions unused (5,736 ) Foreign currencies translation adjustments (1 ) Ending balance 82,621
Changes in asset retirement obligation	(3) Changes in asset retirement obligation are as follows (Unit: Korean Won in millions): For the six months 2018 2017 Beginning balance 61,872 58,076 Provisions provided 1,083 654 Provisions used (295 ) (416 ) Reversal of provisions unused (993 ) (727 ) Amortization 259 203 Increase in restoration costs and others 5,532 4,163 Ending balance 67,458 61,953
Changes in other obligation	(4) Changes in other provisions are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Provisions for Other Total Beginning balance 40,445 58,791 99,236 Provisions provided 36,044 2,236 38,280 Provisions used (48,891 ) (2,199 ) (51,090 ) Reversal of unused amount — (40 ) (40 ) Foreign currencies translation adjustments — (7 ) (7 ) Transfer (*) 5,467 — 5,467 Others 13,670 4,699 18,369 Ending balance 46,735 63,480 110,215 (*) As the credits of the affiliates were transferred to the Group, the allowance for the provisions for customer reward credits increased for the six months ended June 30, 2018. For the six months ended June 30, 2017 Provisions for Other Total Beginning balance 22,093 22,282 44,375 Provisions provided 32,208 2,390 34,598 Provisions used (39,402 ) (9,013 ) (48,415 ) Reversal of unused amount — (40 ) (40 ) Foreign currencies translation adjustments — (146 ) (146 ) Transfer (*) 11,482 — 11,482 Amortization — 53 53 Others 5,667 128 5,795 Ending balance 32,048 15,654 47,702 (*) As the credits of the affiliates were transferred to the Group, the allowance for the provisions for customer reward credits increased for the six months ended June 30, 2017.

Net Defined Benefits Liabilit76

Net Defined Benefits Liability (Asset) (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of defined benefit plans [Abstract]
Net defined benefit liability asset	(1) Details of net defined benefit liability are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Defined benefit obligation 1,175,786 1,071,170 Fair value of plan assets (1,075,927 ) (1,027,906 ) Net defined benefit liability 99,859 43,264
Changes in the carrying value of defined benefit obligation	(2) Changes in the carrying value of defined benefit obligation are as follows (Unit: Korean Won in millions): For the six months For the six months Beginning balance 1,071,170 984,381 Current service cost 72,460 73,564 Interest cost 15,797 13,144 Remeasurements 72,374 4,639 Foreign currencies translation adjustments 8 (121 ) Retirement benefit paid (57,109 ) (31,022 ) Curtailment or settlement — (10,076 ) Others 1,086 127 Ending balance 1,175,786 1,034,636
Changes in the plan assets	(3) Changes in the plan assets are as follows (Unit: Korean Won in millions): For the six months For the six months Beginning balance 1,027,906 990,653 Interest income 16,626 15,127 Remeasurements (9,088 ) (7,847 ) Employer’s contributions 96,273 18,000 Retirement benefit paid (55,790 ) (29,431 ) Curtailment or settlement — (10,396 ) Others — 43,113 Ending balance 1,075,927 1,019,219
Current service cost net interest expense income past service cost loss (gain) on the curtailment or settlement and loss (gain) due to remeasurements	(5) Current service cost, net interest income, loss (gain) on the curtailment or settlement and remeasurements recognized in the consolidated statements of net income and total comprehensive income are as follows (Unit: Korean Won in millions): For the six months For the six months Current service cost 72,460 73,564 Net interest income (829 ) (1,983 ) Loss (gain) on the curtailment or settlement — 321 Cost recognized in net income 71,631 71,902 Remeasurements(*) 81,462 12,486 Cost recognized in total comprehensive income 153,093 84,388 (*) This is an amount before considering the tax effects.
Key actuarial assumptions used in defined benefit liability assessment	(6) Key actuarial assumptions used in defined benefit liability measurement are as follows: June 30, 2018 December 31, 2017 Discount rate 3.25% 3.18% Future wage growth rate 6.18% 6.18% Mortality rate Issued by Korea Insurance Issued by Korea Insurance Retirement rate Experience rate for each Experience rate for each The weighted average maturity of defined benefit liability is 12.94 years.
Sensitivity to actuarial assumptions used in the assessment of defined benefit obligation	(7) The sensitivity to actuarial assumptions used in the assessment of defined benefit obligation is as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Discount rate Increase by 1% point (124,157 ) (116,405 ) Decrease by 1% point 146,273 137,151 Future wage growth rate Increase by 1% point 145,794 136,707 Decrease by 1% point (125,567 ) (117,765 )

Other Financial Liabilities a77

Other Financial Liabilities and Other Liabilities (Tables)	6 Months Ended
	Jun. 30, 2018
Miscellaneous Liabilities [Abstract]
Schedule of miscellaneous other liabilities [Table Text Block]	Other financial liabilities and other liabilities are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Other financial liabilities: Accounts payable 9,021,786 4,692,320 Accrued expenses 1,809,499 2,049,861 Borrowings from trust accounts 3,999,899 3,271,817 Agency business revenue 258,497 344,591 Foreign exchange payables 604,344 590,667 Domestic exchange payables 4,229,125 1,309,646 Other miscellaneous financial liabilities 1,487,513 1,635,156 Present value discount (2,396 ) (1,597 ) Subtotal 21,408,267 13,892,461 June 30, 2018 December 31, 2017 Other liabilities: Unearned income 178,799 180,664 Other miscellaneous liabilities 124,114 103,317 Subtotal 302,913 283,981 Total 21,711,180 14,176,442

Derivatives (Tables)

Derivatives (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of detailed information about hedges [Abstract]
Details of derivative assets and derivative liabilities	(1) Derivative assets and derivative liabilities are as follows (Unit: Korean Won in millions): June 30, 2018 Nominal Assets Liabilities For fair For trading For cash flow For fair For trading Interest rate: Futures 272,778 — — — — — Swaps 143,307,983 12,395 218,551 — 34,540 232,719 Purchase options 660,000 — 10,897 — — — Written options 785,000 — — — — 11,731 Currency: Futures 371,529 — — — — — Forwards 80,082,126 — 1,200,200 — — 1,164,623 Swaps 56,427,354 — 806,790 32,965 — 750,377 Purchase options 2,635,551 — 36,079 — — — Written options 4,651,496 — — — — 49,352 Equity: Futures 124,009 — — — — — Swaps 435,790 — 3,021 — — 4,542 Purchase options 4,272,150 — 115,210 — — — Written options 5,661,146 — — — — 163,966 Others: Futures 965 — — — — — Forward 5,618 — — — — — Swaps 8,081 — 463 — — 440 Total 299,701,576 12,395 2,391,211 32,965 34,540 2,377,750 December 31, 2017 Nominal Assets Liabilities For fair For trading For cash flow For fair For trading Interest rate: Futures 75,845 — — — — — Swaps 130,197,378 59,272 223,935 — 12,103 253,972 Purchase options 630,000 — 12,346 — — — Written options 795,000 — — — — 12,869 December 31, 2017 Nominal Assets Liabilities For fair For trading For cash flow For fair For trading Currency: Futures 318,217 — — — — — Forwards 72,526,956 — 1,314,368 — — 1,375,799 Swaps 48,176,306 — 1,352,924 55,651 — 1,347,905 Purchase options 2,291,154 — 64,267 — — — Written options 4,038,237 — — — — 58,687 Equity: Futures 91,436 — — — — — Swaps 15,000 — 103 — — 10 Purchase options 5,060,706 — 146,775 — — — Written options 4,504,290 — — — — 99,770 Others: Futures — — — — — — Swaps 7,805 — 1,057 — — 1,037 Purchase options — — — — — — Written options 5,000 — — — — 100 Total 268,733,330 59,272 3,115,775 55,651 12,103 3,150,149 Derivatives held for trading are classified into financial assets at FVTPL (Note 7) and financial liabilities at FVTPL (Note 20), and derivatives held for hedging are presented as a separate line item in the consolidated statements of financial position.
Details of nominal amounts of the hedging instrument	(3) The nominal amounts of the hedging instrument as of June 30, 2018 are as follows (Unit: USD, SGD): 1 year or less 1 year to 5 years More than 5 years Total Fair value hedging derivatives Interest rate risk Interest rate swap (USD) 500,000,000 1,350,000,000 1,000,000,000 2,850,000,000 Cash flow hedge Foreign currencies translation risk and interest rate risk Currency swap (USD) 50,000,000 450,000,000 — 500,000,000 Foreign currencies translation risk Currency swap (SGD) — 204,000,000 — 204,000,000
Details of average interest rate and average currency rate of the hedging instrument	(4) The average interest rate and average currency rate of the hedging instrument as of June 30, 2018 are as follows: Average interest rate and average currency rate Fair value hedging derivatives Interest rate risk Interest rate swaps (USD) Fixed 3.98% receipt and 3.96% floating paid Cash flow hedge Foreign currencies translation risk and interest rate risk Currency swap (USD) USD 2.65% receipt, KRW 1.71% paid, USD/KRW = 1,173 Won Foreign currencies translation risk Currency swap (SGD) SGD 1.91% receipt, KRW 1.98% paid, SGD/KRW = 828 Won
Details of amounts related to items designated as heding instruments	(5) The amounts related to items designated as hedging instruments as of June 30, 2018 are as follows (Unit: Korean Won in millions, USD, SGD): Carrying amounts of Line item in the Nominal amounts of Assets Liabilities Changing in fair Fair value hedge Interest rate risk Interest rate swaps USD2,850,000,000 12,395 34,540 Derivative (62,246 ) Cash flow hedge Foreign currencies translation risk and interest rate risk Currency swap USD500,000,000 — 27,594 Derivative 22,013 Foreign currencies translation risk Currency swap SGD204,000,000 — 5,372 Derivative 672
Details of carrying amount to hedge and amount due to hedge accounting	(6) Details of carrying amount to hedged and amount adjusted due to hedge accounting as of June 30, 2018 are as follows (Unit: Korean won in millions): Carrying amounts of Accumulated amount of Line item in the Changing in Cash flow Assets Liabilities Assets Liabilities Fair value hedging Interest rate risk Debenture — 3,150,145 — 60,732 Debentures 66,455 — Cash flow hedge Foreign currencies translation risk and interest rate risk Debenture — 558,258 — — Debentures (21,725 ) (1,665 ) Foreign currencies translation risk Debenture — 166,229 — — Debentures (505 ) (3,770 ) (*) Amount after tax deduction
Details of amounts recognized in profit or loss due to the ineffective portion of fair value hedges	(7) Amounts recognized in profit or loss due to the ineffective portion of fair value hedges during the current period are as follows (Unit: Korean Won in millions): Hedge ineffectiveness Line item in the profit that Fair value hedge Interest rate risk 4,209 Other net operating
Details of reclassification of profit or loss from other comprehensive income and equity related to cash flow hedges	(8) Reclassification of profit or loss from other comprehensive income and equity related to cash flow hedges is as follows (Unit: Korean Won in millions): Changes in Hedge Line item in the Amounts Line item Cash flow hedge Foreign currencies translation risk and interest rate risk 22,043 (30 ) Other net 25,049 Other net Foreign currencies translation risk 672 — Other net 3,894 Other net

Deferred Day 1 Profit or Loss (

Deferred Day 1 Profit or Loss (Tables)	6 Months Ended
	Jun. 30, 2018
Deferred Day One Profit Or Loss [Abstract]
Changes in deferred day one profits or losses [Table Text Block]	Changes in deferred day 1 profits or losses are as follows (Unit: Korean Won in millions): For the six months 2018 2017 Beginning balance 7,416 13,422 New transactions 20,820 500 Amounts recognized in losses (3,000 ) (3,613 ) Ending balance 25,236 10,309

Capital Stock and Capital Sur80

Capital Stock and Capital Surplus (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure Of Issued Capital And Miscellaneous Equity [Abstract]
Number of authorized shares and others	(1) The number of shares authorized and others are as follows: June 30, 2018 December 31, 2017 Shares of common stock authorized 5,000,000,000 Shares 5,000,000,000 Shares Par value 5,000 Won 5,000 Won Shares of common stock issued 676,000,000 Shares 676,000,000 Shares Capital stock 3,381,392 million Won 3,381,392 million Won
Disclosure of issued capital and capital surplus [Table Text Block]	(3) Details of capital surplus are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Capital in excess of par value 269,533 269,533 Other capital surplus 16,352 16,347 Total 285,885 285,880

Hybrid Securities (Tables)

Hybrid Securities (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of other equity interest [Abstract]
Schedule of other equity interest [Table Text Block]	The bond-type hybrid securities classified as owner’s equity are as follows (Unit: Korean Won in millions): Issue date Maturity Interest rate June 30, December 31, Securities in local currency June 20, 2008 June 20, 2038 7.7 — 255,000 April 25, 2013 April 25, 2043 4.4 500,000 500,000 November 13, 2013 November 13, 2043 5.7 200,000 200,000 December 12, 2014 December 12, 2044 5.2 160,000 160,000 June 3, 2015 June 3, 2045 4.4 240,000 240,000 Securities in foreign currencies June 10, 2015 June 10, 2045 5.0 559,650 559,650 September 27, 2016 — 4.5 553,450 553,450 May 16, 2017 — 5.3 562,700 562,700 Issuance cost (12,544 ) (12,912 ) Total 2,763,256 3,017,888

Other Equity (Tables)

Other Equity (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure Of Other Equity [Abstract]
Details of other equity	(1) Details of other equity are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Accumulated other comprehensive loss: Net gain or loss on valuation of financial assets at FVTOCI (46,746 ) — Gain on valuation of AFS financial assets — 301,930 Gain (loss) on financial liabilities at fair value through profit or loss designated as upon initial recognition due to own credit risk 29 — Share of other comprehensive loss of joint ventures and associates (1,446 ) (1,251 ) Loss on foreign currency translation of foreign operations (206,037 ) (242,700 ) Remeasurement loss related to defined benefit plan (211,838 ) (152,624 ) Gain (loss) on valuation of cash flow hedges (5,436 ) 777 Equity related to assets held for sale (564 ) 4,145 Subtotal (472,038 ) (89,723 ) Treasury shares (34,113 ) (34,113 ) Other capital adjustments (1,607,647 ) (1,815,438 ) Total (2,113,798 ) (1,939,274 )
Changes in the accumulated other comprehensive income or loss	(2) Changes in the accumulated other comprehensive loss are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Beginning Increase Reclassification Income tax Ending Net gain or loss on valuation of financial assets at FVTOCI (88,906 ) 58,846 (694 ) (15,992 ) (46,746 ) Gain (loss) on financial liabilities at fair value through profit or loss designated as upon initial recognition due to own credit risk (96 ) 172 — (47 ) 29 Share of other comprehensive gain (loss) of joint ventures and associates (2,656 ) 1,669 — (459 ) (1,446 ) Gain (loss) on foreign currency translation of foreign operations (242,806 ) 50,717 — (13,948 ) (206,037 ) Remeasurement gain (loss) related to defined benefit plan (152,358 ) (82,041 ) — 22,561 (211,838 ) Gain (loss) on valuation of cash flow hedges 777 (8,570 ) — 2,357 (5,436 ) Transfer to non-current 4,145 (564 ) (4,145 ) — (564 ) Total (481,900 ) 20,229 (4,839 ) (5,528 ) (472,038 ) (*1) The beginning balance was restated in accordance with IFRS 9. (*2) Net gain or loss on valuation of financial assets at FVTOCI included the 1,500 million Won transfer to retained earnings due to disposal of equity securities. For the six months ended June 30, 2017 Beginning Increase Reclassification Income tax Ending Gain (loss) on valuation of AFS financial assets 386,981 46,479 (81,114 ) 5,602 357,948 Share of other comprehensive income (loss) of joint ventures and associates (1,863 ) 2,038 — (531 ) (356 ) Gain (loss) on foreign currency translation of foreign operations (48,353 ) (81,571 ) — 17,627 (112,297 ) Remeasurement gain (loss) related to defined benefit plan (163,397 ) (12,642 ) — 3,020 (173,019 ) Gain (loss) on valuation of cash flow hedges — (1,947 ) — 421 (1,526 ) Total 173,368 (47,643 ) (81,114 ) 26,139 70,750 (*) For the change in gain (loss) on valuation of AFS financial assets, “increase (decrease)” represents change due to the valuation during the period, and “reclassification adjustments” represents disposal or recognition of impairment losses on AFS financial assets.

Retained Earnings (Tables)

Retained Earnings (Tables)	6 Months Ended
	Jun. 30, 2018
Retained Earnings Note Disclosure [Abstract]
Schedule of appropriated and unappropriated retained earnings [Table Text Block]	(1) Details of retained earnings are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Legal reserve Earned surplus reserve 1,857,754 1,729,754 Other legal reserve 46,384 45,668 Subtotal 1,904,138 1,775,422 Voluntary reserve Business rationalization reserve 8,000 8,000 Reserve for financial structure improvement 235,400 235,400 Additional reserve 7,759,804 7,418,806 Regulatory reserve for credit loss 2,578,457 2,438,191 Revaluation reserve 715,860 751,964 Other voluntary reserve — 11,700 Subtotal 11,297,521 10,864,061 Conversion of loss on disposal of equity securities at FVTOCI to retained earnings (424 ) — Derecognition of the credit risk on financial liabilities designated at FVTPL 5 — Retained earnings before appropriation 3,272,213 2,980,523 Total 16,473,453 15,620,006
Changes in retained earnings [Table Text Block]	(2) Changes in retained earnings are as follows (Unit: Korean Won in millions): For the six months ended June 30 2018 (*) 2017 Beginning balance 15,797,097 14,611,566 Net attributable to owners 1,305,878 1,098,361 Dividends on common stock (336,636 ) (269,308 ) Dividends on hybrid securities (75,603 ) (90,823 ) Loss on disposal of equity securities at FVTOCI (424 ) — Derecognition of the credit risk on financial liabilities designated at FVTPL 5 — Capital adjustments due to appropriation of retained earnings (216,864 ) — Ending balance 16,473,453 15,349,796 (*) The beginning balance as of 2018 was restated in accordance with IFRS 9.

Net Interest Income (Tables)

Net Interest Income (Tables)	6 Months Ended
	Jun. 30, 2018
Interest Revenue (Expense), Net [Abstract]
Details of interest income	(1) Interest income recognized is as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Financial assets at FVTPL (IFRS 9) 13,367 28,537 — — Financial assets at FVTPL (IAS 39) — — 13,074 26,806 Financial assets at FVTOCI 62,170 119,446 — — AFS financial assets — — 67,667 144,067 Securities at amortized cost 87,587 168,789 — — HTM financial assets — — 74,690 149,673 Financial assets at amortized cost: Interest on due from banks 28,323 61,461 — — Interest on loans 2,170,291 4,251,497 — — Interest of other receivables 6,931 13,686 — — Subtotal 2,205,545 4,326,644 — — Loans and receivables: Interest on due from banks — — 20,182 41,403 Interest on loans — — 1,921,359 3,810,008 Interest of other receivables — — 8,836 17,627 Subtotal — — 1,950,377 3,869,038 Total 2,368,669 4,643,416 2,105,808 4,189,584
Details of interest expense	(2) Interest expense recognized is as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Interest on deposits due to customers 704,007 1,358,964 586,051 1,174,384 Interest on borrowings 70,519 129,929 57,666 115,548 Interest on debentures 174,890 346,948 154,445 305,804 Other interest expense 21,930 43,101 20,070 43,528 Total 971,346 1,878,942 818,232 1,639,264

Net Fees and Commissions Inco85

Net Fees and Commissions Income (Tables)	6 Months Ended
	Jun. 30, 2018
Fee and commission income (expense) [Abstract]
Schedule of fee and commission income [Table Text Block]	(1) Details of fees and commissions income recognized are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Fees and commissions received (*) 169,171 346,925 163,688 336,322 Fees and commissions received for provision of guarantee 14,660 30,263 15,911 31,700 Fees and commissions received on project financing 10,528 16,945 4,614 6,334 Fees and commissions received on credit card 283,407 556,984 268,887 527,566 Fees and commissions received on securities 23,767 50,238 19,757 40,267 Other fees and commissions received 53,867 111,651 33,424 71,704 Total 555,400 1,113,006 506,281 1,013,893 (*) Fees and commissions received include fees income from agency commission, fees income from electronic finance, fees income related to loan, fees for import letter of credit dealing, commission received on foreign exchange and others.
Schedule of fee and commission expense [Table Text Block]	(2) Details of fees and commissions expense incurred are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Fees and commissions paid 41,532 80,866 41,930 73,167 Credit card commission 213,887 425,204 200,275 400,349 Brokerage commission 934 1,268 121 348 Others 1,700 3,013 1,207 2,329 Total 258,053 510,351 243,533 476,193

Dividend Income (Tables)

Dividend Income (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure Of Revenue From Dividends [Abstract]
Schedule of revenue from dividends [Table Text Block]	(1) Details of dividend income recognized are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Financial assets at FVTPL (IFRS 9) 12,210 31,860 — — Financial assets at FVTPL (IAS 39) — — 47 190 Financial assets at FVTOCI 1,941 17,844 — — AFS financial assets — — 19,570 59,255 Total 14,151 49,704 19,617 59,445
Details of dividend income related to financial assets at fair value through other comprehensive income	(2) Details of dividends related to financial assets at FVTOCI are as follows (Unit: Korean Won in millions): Six month ended Dividend income recognized from assets held Equity securities 17,570 Dividend income recognized in assets derecognized 274 Total 17,844

Net gain or loss on financial87

Net gain or loss on financial instruments at fair value through profit or loss mandatorily measured at fair value (IFRS 9 and IAS 39) (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of gains (losses) on financial instruments at fair value through profit or loss [Abstract]
Details of gains or losses related to financial assets at fair value through profit or loss	(1) Details of gains or losses related to net gain or loss on financial instruments at FVTPL (IFRS 9 and IAS 39) are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Gains on financial assets at fair value through profit or loss mandatorily measured at fair value 70,116 114,146 — — Gains (losses) on financial instruments held for trading — — 36,266 (60,186 ) Gains (losses) on financial instrument at fair value through profit or loss designated as upon initial recognition (2,423 ) 2,877 — — Losses on financial instruments at fair value through profit or loss designated as upon initial recognition — — (24,200 ) (86,223 ) Total 67,693 117,023 12,066 (146,409 )
Gains or losses on financial assets held for trading	(2) Details of net gain or loss on financial instrument at fair value through profit or loss mandatorily measured at fair value and financial assets held for trading are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Financial assets at FVTPL (financial assets held for trading) Securities Gain on valuation 36,982 81,861 1,055 5,895 Gain on disposals 18,885 22,377 3,936 9,860 Loss on valuation (11,957 ) (23,795 ) (2,785 ) (6,511 ) Loss on disposals (7,481 ) (9,180 ) (1,308 ) (2,057 ) Subtotal 36,429 71,263 898 7,187 Loans Gain on valuation 373 3,191 — — Loss on valuation (107 ) (127 ) — — Subtotal 266 3,064 — — Other financial assets Gain on valuation 228 1,969 1,495 3,071 Gain on disposals 143 405 814 933 Loss on valuation (320 ) (2,193 ) (1,971 ) (3,590 ) Loss on disposals (11 ) (83 ) (211 ) (234 ) Subtotal 40 98 127 180 Total of financial assets held for trading 36,735 74,425 1,025 7,367 2018 2017 Three months Six months Three months Six months Derivatives (for trading) Interest rates derivatives Gain on transactions and valuation 231,372 600,362 201,637 433,349 Loss on transactions and valuation (247,381 ) (594,525 ) (198,170 ) (421,734 ) Subtotal (16,009 ) 5,837 3,467 11,615 Currency derivatives Gain on transactions and valuation 2,546,154 3,535,106 (94,206 ) 3,773,565 Loss on transactions and valuation (2,502,934 ) (3,505,890 ) 105,055 (3,943,609 ) Subtotal 43,220 29,216 10,849 (170,044 ) Equity derivatives Gain on transactions and valuation 115,712 249,364 92,302 302,927 Loss on transactions and valuation (109,288 ) (244,063 ) (71,116 ) (211,551 ) Subtotal 6,424 5,301 21,186 91,376 Other derivatives Gain on transactions and valuation 2,142 2,790 2,295 12,312 Loss on transactions and valuation (2,396 ) (3,423 ) (2,556 ) (12,812 ) Subtotal (254 ) (633 ) (261 ) (500 ) Total of derivatives (for trading) 33,381 39,721 35,241 (67,553 ) Total 70,116 114,146 36,266 (60,186 )
Gains or losses on financial assets designated at fair value through profit or loss	(3) Details of net gain or loss on financial instrument at fair value through profit or loss designated as upon initial recognition are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Gain (loss) on equity-linked securities: Loss on disposals of equity-linked securities (1,203 ) (1,534 ) (3,686 ) (15,877 ) Gain (loss) on valuation of equity-linked securities (2,164 ) 2,814 (20,667 ) (69,714 ) Subtotal (3,367 ) 1,280 (24,353 ) (85,591 ) Loss on other securities: Loss on valuation of other securities — — (114 ) (16 ) Gain (loss) on other financial instruments: Gain (loss) on valuation of other financial instruments 944 1,597 267 (616 ) Total (2,423 ) 2,877 (24,200 ) (86,223 )

Gains (losses) on financial a88

Gains (losses) on financial assets at vair value through other comprehensiveIncome and available-for-sale financial assets (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of gains losses recognised in profit or loss available-for-sale securities [Abstract]
Details of Gains (Losses) on financial assets at fair value through other comprehensive income and available-for-sale financial assets	Details of net gain on financial assets at FVTOCI and AFS financial assets recognized are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Gains on redemption of securities 11 16 220 547 Gains on transaction of securities 464 1,271 95,019 116,262 Impairment losses on securities — — (6,852 ) (12,637 ) Total 475 1,287 88,387 104,172

Impairment Losses Due to Cred89

Impairment Losses Due to Credit Loss (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of impairment loss and reversal of impairment loss [Abstract]
Impairment losses on loans and receivables guarantees and loan commitment recognized for credit loss	38. REVERSAL OF ALLOWANCE FOR (IMPAIRMENT LOSSES DUE TO) CREDIT LOSS Reversal of allowance for (Impairment losses due to) credit loss are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Reversal of credit loss on financial assets at FVTOCI (679 ) (459 ) — — Reversal of credit loss on securities at amortized cost losses (199 ) (191 ) — — Provision for credit loss on loans and other financial assets at amortized cost 76,699 (61,057 ) — — Impairment losses due to credit loss — — (211,842 ) (333,976 ) Reversal of provision on guarantee 76,354 86,990 16,071 44,968 Reversal of provision on (provision for) loan commitment (1,502 ) 3,155 (8,715 ) 5,245 Total 150,673 28,438 (204,486 ) (283,763 )

General administrative expens90

General administrative expenses and other operating incomes (expenses) (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of general administrative expenses and other operating income (expense) [Abstract]
Details of administrative expenses	(1) Details of general and administrative expenses recognized are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Salaries Short term employee benefits Salaries 341,645 644,663 326,034 654,191 Employee benefits 108,933 213,627 114,170 213,600 Retirement benefit service costs 36,610 72,936 36,972 74,057 Termination 20,994 20,994 5,477 5,477 Subtotal 508,182 952,220 482,653 947,325 F-90 2018 2017 Three months Six months Three months Six months Depreciation and amortization 52,222 99,698 45,380 94,927 Other general and administrative expenses Rent 79,546 159,126 76,297 156,708 Taxes and public dues 38,275 67,385 34,077 63,178 Service charges 52,807 104,970 47,611 96,418 Computer and IT related 21,704 43,581 16,089 30,477 Telephone and communication 16,819 33,729 16,111 31,590 Operating promotion 9,339 19,768 10,003 21,053 Advertising 13,808 20,493 22,434 29,880 Printing 1,928 3,892 2,095 4,237 Traveling 2,679 6,034 2,920 6,024 Supplies 1,737 3,223 1,517 3,117 Insurance premium 1,961 4,002 1,956 4,169 Reimbursement 4,964 5,902 4,710 9,177 Maintenance 3,672 8,027 3,331 6,882 Water, light, and heating 2,809 7,203 2,883 7,146 Vehicle maintenance 2,379 4,594 2,602 4,964 Others 12,823 23,491 11,488 21,155 Subtotal 267,250 515,420 256,124 496,175 Total 827,654 1,567,338 784,157 1,538,427
Details of other operating incomes	(2) Details of other operating income recognized are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Gains on transaction of foreign exchange 157,245 847,397 619,297 1,698,987 Gains on disposal of loans and receivables (*1) — — 14,861 201,860 Gains related to derivatives 26,373 28,943 11,592 11,656 Gains on fair value hedged items 18,861 66,555 (7,094 ) 11,860 Others (*2) 1,741 17,522 5,813 68,668 Total 204,220 960,417 644,469 1,993,031 (*1) Gain on disposal of loan and receivables occurred for the six month ended June 30, 2018 was presented into a separate account for gain related to financial assets at amortized cost in accordance with the adoption of IFRS 9. (*2) Other income includes such income amounting to 28,800 million Won for the six months ended June 30, 2017, respectively, that the Group recognized for it is to receive from other creditor financial institutions in accordance with the creditor financial institutions committee agreement.
Details of other operating expenses	(3) Details of other operating expenses recognized are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Losses on transactions of foreign exchange 114,971 726,348 534,740 1,374,764 KDIC deposit insurance premium 79,585 156,765 77,146 150,256 Contribution to miscellaneous funds 73,849 146,781 71,927 144,262 Losses (Gains) on disposals of loans and receivables (*1) — — (40 ) 28 Losses (Gains) related to derivatives 13,059 62,366 (16,441 ) 31,131 Losses on fair value hedged items — — 15,820 15,846 Others (*2) 45,707 87,571 38,584 75,554 Total 327,171 1,179,831 721,736 1,791,841 (*1) Loss on disposal of loan and receivables occurred for the six month ended June 30, 2018 was presented into a separate account for loss related to financial assets at amortized cost in accordance with the adoption of IFRS 9. (*2) Other expense includes such expenses amounting to 1,412 million Won and 3,325 million Won for the six months ended June 30, 2018 and 2017, respectively, which are related to the Group’s expected payments to other creditor financial institutions in accordance with the creditor financial institutions committee agreement. In addition, ‘Other expense’ for the six months ended June 30, 2018 and 2017 includes 25,179 million Won and 24,443 million Won, respectively, of intangible asset amortization expense.

Other non-operating income (e91

Other non-operating income (expense) (Tables)	6 Months Ended
	Jun. 30, 2018
Other non-operating income (expense) [Abstract]
Details of gain or loss on valuation of investments in joint ventures and associates	(1) Details of gains or losses on valuation of investments in joint ventures and associates are as follows (Unit: Korean Won in millions): 2018 2017 Three months Six months Three months Six months Gain on valuation 10,687 15,347 (10,061 ) 3,316 Loss on valuation (3,006 ) (16,809 ) 521 (62,271 ) Impairment loss — — (5,323 ) (5,323 ) Total 7,681 (1,462 ) (14,863 ) (64,278 )
Other non-operating incomes and expenses	(2) Details of other non-operating 2018 2017 Three months Six months Three months Six months Other non-operating 23,345 39,041 30,411 77,185 Other non-operating (21,947 ) (43,762 ) (18,714 ) (67,187 ) Total 1,398 (4,721 ) 11,697 9,998
Details of other non-operating incomes	(3) Details of other non-operating 2018 2017 Three months Six months Three months Six months Rental fee income 1,687 3,203 1,880 3,700 Gains on disposal of investments in joint ventures and associates — — 4,466 32,886 Gains on disposal of premises and equipment, intangible assets and other assets 15,760 17,037 1,494 1,675 Reversal of impairment loss of premises and equipment, intangible assets and other assets 1 341 — 32 Others 5,897 18,460 22,571 38,892 Total 23,345 39,041 30,411 77,185
Details of other non-operating expenses	(4) Details of other non-operating 2018 2017 Three months Six months Three months Six months Depreciation on investment properties 1,004 2,010 992 1,991 Interest expense of rent leasehold deposits 150 292 105 223 Losses on disposal of investment in joint ventures and associates — 2,931 46 27,730 Losses on disposal of premises and equipment, intangible assets and other assets 167 221 271 608 Impairment losses of premises and equipment, intangible assets and other assets 2 2 40 160 Donation 8,551 22,042 10,426 14,980 Others 12,073 16,264 6,834 21,495 Total 21,947 43,762 18,714 67,187

Income Tax Expense (Tables)

Income Tax Expense (Tables)	6 Months Ended
	Jun. 30, 2018
Major components of tax expense (income) [Abstract]
Details of income tax expenses	(1) Details of income tax expenses are as follows (Unit: Korean Won in millions): For the six months 2018 2017 Current tax expense Current tax expense in respect of the current period 231,393 284,030 Adjustments recognized in the current period in relation to the current tax of prior periods (3,632 ) (4,919 ) Subtotal 227,761 279,111 Deferred tax expense Deferred tax assets (liabilities) relating to the origination and reversal of temporary differences 182,515 13,889 Deferred tax charged directly to equity (378 ) 27,933 Others (tax effect charged directly to equity due to the adoption of IFRS 9) 75,318 — Subtotal 257,455 41,822 Income tax expense 485,216 320,933
Relationship between net income loss before income tax expense and Income tax expense benefit	(2) Income tax expense reconciled to net income before income tax expense is as follows (Unit: Korean Won in millions): For the six months 2018 2017 Net income before income tax expense 1,801,532 1,429,948 Tax calculated at statutory tax rate (*) 490,240 345,585 Adjustments Effect of income that is exempt from taxation (19,695 ) (32,683 ) Effect of expense not deductible in determining taxable profit 9,395 9,624 Adjustments recognized in the current period in relation to the current tax of prior periods (3,632 ) (4,919 ) Others 8,908 3,326 Subtotal (5,024 ) (24,652 ) Income tax expense 485,216 320,933 Effective tax rate 26.9 % 22.4 % (*) The applicable income tax rate; 1) 11% for below 200 million Won, 2) 22% for above 200 million Won and below 20 billion Won, 3) 24.2% for above 20 billion Won and below 300 billion Won, 4) 27.5% for above 300 billion Won.
Changes in Deferred tax assets and liabilities	(3) Details of accumulated deferred tax charged directly to equity are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Net gain on valuation of financial assets at FVTOCI 18,568 — Loss on valuation of AFS securities — (114,169 ) Share of other comprehensive gain (loss) of joint ventures and associates 378 (954 ) Foreign currency translation of foreign operations 6,852 15,855 Remeasurements of the net defined benefit liability 78,685 56,317 Gain (loss) on cash flow hedge 1,735 (248 ) Total 106,218 (43,199 )

Earnings per Share (Tables)

Earnings per Share (Tables)	6 Months Ended
	Jun. 30, 2018
Earnings per share [Abstract]
Details of earnings per share	Basic EPS is calculated by dividing net income by weighted average number of common shares outstanding (Unit: Korean Won in millions, except for EPS and number of shares): 2018 2017 Three months Six months Three months Six months Net income attributable to Owners 716,142 1,305,878 460,888 1,098,361 Dividends to hybrid securities (37,748 ) (75,603 ) (41,557 ) (90,823 ) Net income attributable to common shareholders 678,394 1,230,275 419,331 1,007,538 Weighted average number of common shares outstanding 673 shares 673 shares 673 shares 673 shares Basic EPS 1,008 1,828 623 1,497 Diluted EPS is equal to basic EPS because there is no dilution effect for the three and six months ended June 30, 2018 and 2017.

Contingent Liabilities and Co94

Contingent Liabilities and Commitments (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of contingent liabilities [Abstract]
Details of guarantees	(1) Details of guarantees are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Confirmed guarantees Guarantee for loans 141,193 157,299 Acceptances 333,365 320,519 Guarantees in acceptances of imported goods 106,675 108,238 Other confirmed guarantees 5,981,767 6,288,965 Sub-total 6,563,000 6,875,021 Unconfirmed guarantees Local letter of credit 365,302 383,117 Letter of credit 3,207,797 3,637,787 Other unconfirmed guarantees 936,971 505,689 Sub-total 4,510,070 4,526,593 Commercial paper purchase commitments and others 1,299,503 1,458,101 Total 12,372,573 12,859,715
Details of loan commitments and others	(2) Details of loan commitments and others are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 Loan commitments 98,251,006 80,760,325 Other commitments 5,942,784 4,546,090
Litigation case [Table Text Block]	(3) Litigation case Legal cases where the Group is involved are as follows (Unit: Korean Won in millions): June 30, 2018 December 31, 2017 As plaintiff As defendant As plaintiff As defendant Number of cases (*) 68 cases 161 cases 83 cases 155 cases Amount of litigation 443,234 256,147 413,267 244,767 Provisions for litigations 19,887 9,277 (*) The number of lawsuits as of June 30, 2018 and December 31, 2017 does not include fraud lawsuits, etc. and those lawsuits that are filed only to extend the statute of limitation.

Related Party Transactions (Tab

Related Party Transactions (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of transactions between related parties [Abstract]
Details of related parties	(1) Related parties Related parties Associates Kumho Tire Co., Inc., Woori Service Networks Co., Ltd., Korea Credit Bureau Co., Ltd., Korea Finance Security Co., Ltd., Chin Hung International Inc., STX Corporation, 2016KIF-IMM
Assets and liabilities from transactions with related parties	(2) Assets and liabilities from transactions with related parties are as follows (Unit: Korean Won in millions): Related party A title of account June 30, December 31, Associates Kumho Tire Co., Inc. Loans 257,856 170,917 Loss allowance (62,957 ) (156,712 ) Deposits due to customers 482 666 Other liabilities 489 50 Woori Service Networks Co., Ltd. Loans 22 45 Deposits due to customers 1,732 1,311 Other liabilities 339 357 Korea Credit Bureau Co., Ltd. Loans 4 6 Deposits due to customers 1,063 5,586 Other liabilities 6 54 Korea Finance Security Co., Ltd. Loans 42 56 Loss allowance (2 ) — Deposits due to customers 3,078 2,854 Other liabilities 4 7 Chin Hung International Inc. Loans 182 408 Loss allowance (24 ) (22 ) Deposits due to customers 61,551 46,220 Other liabilities 2,899 1,658 Poonglim Industrial Co., Ltd. (*1) Deposits due to customers — 4 STX Engine Co., Ltd. (*2) Loans — 106,176 Loss allowance — (88,734 ) Deposits due to customers — 18,092 Other liabilities — 29 STX Corporation Loans 73,519 47,711 Loss allowance (49,734 ) (31,210 ) Deposits due to customers 2,130 77,555 Other liabilities 131 80 Associates K BANK Co., Ltd. Loans 103 212 Well to Sea No.3 Private Equity Fund Loans 85,000 73,810 Loss allowance (85 ) (39 ) Deposits due to customers 3,213 61 Other liabilities 69 27 Related party A title of account June 30, December 31, Others (*3) Loans 260 499 Loss allowance (235) (471) Other assets 1 1 Deposits due to customers 6,369 2,906 Other liabilities 153 73 (*1) The Group did not have significant influence over the entity due to the fact that the entity was going through workout process under receivership, and thus the entity was excluded from the investment in associates (*2) The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018. (*3) Others include Saman Corporation, Kyesan Engineering Co., Ltd., Hyunwoo International Co., Ltd., DAEA SNC Co., Ltd. and others as of June 30, 2018 and December 31, 2017.
Gain or loss from transactions with related parties	(3) Gain or loss from transactions with related parties are as follows (Unit: Korean Won in millions): For the six months Related party A title of account 2018 2017 Corporation that has significant influence over the group KDIC (*1) Interest expenses — 15,331 Associates Kumho Tire Co., Inc. Interest income 1,098 1,501 Fees income — 6 Impairment losses due to credit loss (reversal of allowance for credit loss) (93,755) 1,042 Woori Blackstone Korea Opportunity Private Equity Fund No.1 (*2) Fees income — 29 Woori Service Networks Co., Ltd. Other income 15 15 Interest expenses 7 13 Fees expenses 270 335 Other expenses 231 249 Korea Credit Bureau Co., Ltd. Interest expenses 21 38 Fees expenses 1,038 1,023 Korea Finance Security Co., Ltd. Interest expenses 4 5 Impairment losses due to credit loss 2 — Fees expenses 71 — Chin Hung International Inc. Interest income — 53 Fees income — 1 Interest expenses 21 13 Impairment losses due to credit loss (reversal of allowance for credit loss) 2 (4,270) For the six months Related party A title of account 2018 2017 Associates STX Engine Co., Ltd (*3). Interest income 333 672 Fees income — 28 Interest expenses 86 72 Reversal of allowance for credit loss (88,734) (1,835) Samho International Co., Ltd. (*4) Interest income — 364 Fees income — 6 Interest expenses — 214 Reversal of allowance for credit loss — (116) STX Corporation Interest income — 219 Fees income — 58 Interest expenses 2 4 Impairment losses due to credit loss (reversal of allowance for credit loss) 18,524 (59,507) K BANK Co., Ltd. Fees income 514 396 Other income 5 1,051 Well to Sea No.3 Interest income 1,288 — Private Equity Fund (*5) Interest expenses 4 — Impairment losses due to credit loss 46 — Others (*6) Other income 6 — Interest expenses 22 5 Reversal of impairment losses due to credit loss (236) (10) (*1) As its ownership interest in the Group is lower than 20% as of December 31, 2017, it has been excluded from the corporation that have significant influence over the Group. (*2) Due to disposition previous year, the entity is not in scope for associate. (*3) The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018. (*4) The entity was sold after it was transferred to assets held for sale and was excluded from the investment in associates for the year ended December 31, 2017. (*5) Due to capital contribution for the year ended December 31, 2017, the entity has been included in the investment in associates. (*6) Others include the amount transacted with Saman Corporation, Kyesan Engineering Co., Ltd., Hyunwoo International Co., Ltd., DAEA SNC Co., Ltd. and others for the six months ended June 30, 2018 and 2017.
Major loan transactions with related parties	(4) Major loan transactions with related parties for the six months ended June 30, 2018 and June 30, 2017 are as follows (Unit: Korean Won in millions): For the six months ended June 30, 2018 Related parties Beginning Loan Collection Others Ending Associates Kumho Tire Co., Inc. 57,470 — 7,057 — 50,413 Well to Sea No. 3 Private Equity Fund (*2) 73,810 11,190 — — 85,000 STX Engine Co., Ltd. (*3) 39,886 — 2,177 (37,709 ) — For the six months ended June 30, 2017 Related parties Beginning Loan Collection Others Ending Associates Kumho Tire Co., Inc. 50,413 — — — 50,413 STX Engine Co., Ltd. (*3) 44,797 — 7,088 — 37,709 (*1) Settlement payment caused in operation among the related parties were excluded, and in the case of a limited loan, it was presented as a net increase (decrease). (*2) The entity is in scope for the associates due to contribution as of the year ended December 31, 2017. (*3) The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018.
Guarantees provided to the related parties	(6) Guarantees provided to the related parties are as follows (Unit: Korean Won in millions): June 30, December 31, Warranty Kumho Tire Co., Inc. 13,830 4,181 Import credit in foreign currencies and others 511 636 Loan commitment Korea Finance Security Co., Ltd. 218 204 Loan commitment Korea Credit Bureau Co., Ltd. 31 29 Loan commitment Woori Service Networks Co., Ltd. 178 155 Loan commitment Chin Hung International Inc. 32,117 31,891 Loan commitment STX Engine Co., Ltd. (*) — 68,858 Import credit in foreign currencies and others STX corporation 14,914 17,557 Import credit in foreign currencies and others 132 53 Loan commitment K BANK Co., Ltd. 101 — Loan commitment Well to Sea No. 3 Private Equity Fund 225,000 236,190 Loan commitment (*) The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018. For the guarantee provided to the related parties, the Group recognized provisions for guarantees amounting to 11,525 million Won and 71,459 million Won, as of June 30, 2018 and December 31, 2017, respectively.
Compensation for key management	(7) Compensation for key management is as follows (Unit: Korean Won in millions): For the six months 2018 2017 Short term benefits 6,023 6,524 Severance payments 280 280 Total 6,303 6,804 Key management includes registered executives and non-registered

Business Combination (Tables)

Business Combination (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of detailed information about business combination [Abstract]
Acquisition accounting of business combination [Table Text Block]	(2) Details of the accounting for the business combination are as follows (Unit: Korean Won in millions): June 30, 2018 Consideration transferred: Cash and cash equivalents 88,216 Identifiable assets and liabilities recognized: Cash and cash equivalents 16,657 Financial assets at FVTOCI 17 Loans and other financial assets at amortized cost 205,451 Premises and equipment 1,630 Intangible assets 763 Current tax assets 173 Deferred tax assets 1,381 Other assets 1,510 Total assets 227,582 Deposits due to customers 54,615 Borrowings 120,644 Other financial liabilities 6,149 Current tax liabilities 640 Other liabilities 4,724 Total liabilities 186,772 Identifiable net fair value 40,810 Goodwill(*) 47,406 (*) Identifying the intangible assets and measuring the fair value of identifiable assets acquired are incomplete as the acquisition date was June 21, 2018. The amount of Goodwill could change due to the result of the measurement of the identifiable assets and liabilities.

General_General Information (De

General_General Information (Details) $ in Thousands, ₩ in Millions	6 Months Ended
	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Disclosure of notes and other explanatory information [Abstract]
Name of reporting entity or other means of identification	Woori Bank and subsidiaries
Name of parent entity	Woori Bank
Description of entity incorporation	established in 1899
Description of nature of entitys operations and principal activities	engaged in the commercial banking business under the Banking Act, trust business and foreign exchange business under the Financial Investment Services and Capital Market Act.
Change of holding company	Previously, Woori Finance Holdings Co., Ltd., the former holding company of Woori Financial Group, established on March 27, 2001 held a 100% ownership of the Bank. Effective November 1, 2014, Woori Finance Holdings Co., Ltd. completed its merger (the “Merger”) with and into the Bank. Accordingly, the shares of the Bank, 597 million shares, prior to the merger, were reduced to nil in accordance with capital reduction procedure, and then, in accordance with the merger ratio, the Bank newly issued 676 million shares.
Information of listing on stock market	On June 24, 2002, Woori Finance Holdings Co., Ltd. listed its common shares on the Korea Exchange through public offering. In addition, on September 29, 2003, the holding company registered with the Securities and Exchange Commission in the United States of America and, on the same day, listed its American Depositary Shares on the New York Stock Exchange. As Woori Finance Holdings Co., Ltd. was merged into the Bank, the Bank, which is the existing company, succeeded such rights and obligations as a listed company on the Korea Exchange and the New York Stock Exchange.
Issued capital	₩ 3,381,392	$ 3,041,367	₩ 3,381,392
Information of incorporated subsidiaries	As a result of such merger, the Bank incorporated Woori Card Co., Ltd., Woori Investment Bank Co., Ltd., Woori FIS Co., Ltd., Woori Private Equity Asset Management Co., Ltd., and Woori Finance Research Institute Co., Ltd. as its subsidiaries.
Address of registered office of entity	The headquarters of the Bank is located in 51, Sogong-ro, Jung Gu, Seoul, Korea.
Description of additional information of number of branches and offices	The Bank has 880 branches and offices in Korea, and 23 branches and offices overseas as of June 30, 2018.

General_Consolidated subsidiari

General_Consolidated subsidiaries and their financial information (Details) - KRW (₩)		6 Months Ended		12 Months Ended
		Jun. 30, 2018		Dec. 31, 2017
Woori FIS Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori FIS Co., Ltd.		Woori FIS Co., Ltd.
Main business		System software development & maintenance		System software development & maintenance
Percentage of ownership		100.00%		100.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 80,851,000,000		₩ 103,932,000,000
Liabilities		55,312,000,000		71,386,000,000
Operating revenue		138,088,000,000		252,460,000,000
Net income (loss) attributable to owners		(7,006,000,000)		1,940,000,000
Comprehensive income (loss) attributable to owners		₩ (7,040,000,000)		₩ (2,963,000,000)
Woori Private Equity Asset Management Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori Private Equity Asset Management Co., Ltd.		Woori Private Equity Asset Management Co., Ltd.
Main business		Finance		Finance
Percentage of ownership		100.00%		100.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 40,799,000,000		₩ 42,894,000,000
Liabilities		2,064,000,000		2,670,000,000
Operating revenue		556,000,000		7,257,000,000
Net income (loss) attributable to owners		(1,493,000,000)		(4,114,000,000)
Comprehensive income (loss) attributable to owners		₩ (1,490,000,000)		₩ (4,074,000,000)
Woori Finance Research Institute Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori Finance Research Institute Co., Ltd.		Woori Finance Research Institute Co., Ltd.
Main business		Other service business		Other service business
Percentage of ownership		100.00%		100.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 4,314,000,000		₩ 3,790,000,000
Liabilities		615,000,000		350,000,000
Operating revenue		2,776,000,000		4,733,000,000
Net income (loss) attributable to owners		258,000,000		83,000,000
Comprehensive income (loss) attributable to owners		₩ 258,000,000		₩ 64,000,000
Woori Card Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori Card Co., Ltd.		Woori Card Co., Ltd.
Main business		Finance		Finance
Percentage of ownership		100.00%		100.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 9,100,890,000,000		₩ 8,605,993,000,000
Liabilities		7,462,577,000,000		6,973,705,000,000
Operating revenue		944,657,000,000		1,771,157,000,000
Net income (loss) attributable to owners		67,618,000,000		101,214,000,000
Comprehensive income (loss) attributable to owners		₩ 62,866,000,000		₩ 107,321,000,000
Woori Investment Bank Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori Investment Bank Co., Ltd		Woori Investment Bank Co., Ltd
Main business		Other credit finance business		Other credit finance business
Percentage of ownership		59.80%		59.80%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 2,723,251,000,000		₩ 1,880,157,000,000
Liabilities		2,418,664,000,000		1,588,610,000,000
Operating revenue		109,428,000,000		183,376,000,000
Net income (loss) attributable to owners		14,722,000,000		20,023,000,000
Comprehensive income (loss) attributable to owners		₩ 14,878,000,000		₩ 20,210,000,000
Woori Credit Information Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori Credit Information Co., Ltd.		Woori Credit Information Co., Ltd.
Main business		Credit information		Credit information
Percentage of ownership		100.00%		100.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 34,130,000,000		₩ 33,298,000,000
Liabilities		6,167,000,000		6,175,000,000
Operating revenue		17,601,000,000		31,580,000,000
Net income (loss) attributable to owners		839,000,000		861,000,000
Comprehensive income (loss) attributable to owners		₩ 839,000,000		₩ 752,000,000
Woori America Bank
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori America Bank		Woori America Bank
Main business		Finance		Finance
Percentage of ownership		100.00%		100.00%
Location		U.S.A.		U.S.A.
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 2,073,420,000,000		₩ 1,954,301,000,000
Liabilities		1,777,327,000,000		1,679,248,000,000
Operating revenue		42,624,000,000		81,337,000,000
Net income (loss) attributable to owners		11,186,000,000		11,869,000,000
Comprehensive income (loss) attributable to owners		₩ 24,091,000,000		₩ (16,833,000,000)
Woori Global Markets Asia Limited
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori Global Markets Asia Limited		Woori Global Markets Asia Limited
Main business		Finance		Finance
Percentage of ownership		100.00%		100.00%
Location		Hong Kong		Hong Kong
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 406,684,000,000		₩ 290,226,000,000
Liabilities		287,622,000,000		178,343,000,000
Operating revenue		7,302,000,000		11,345,000,000
Net income (loss) attributable to owners		2,156,000,000		1,922,000,000
Comprehensive income (loss) attributable to owners		₩ 7,298,000,000		₩ (12,544,000,000)
Woori Bank China Limited
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori Bank China Limited		Woori Bank China Limited
Main business		Finance		Finance
Percentage of ownership		100.00%		100.00%
Location		China		China
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 5,120,070,000,000		₩ 4,960,637,000,000
Liabilities		4,596,883,000,000		4,458,683,000,000
Operating revenue		143,390,000,000		388,913,000,000
Net income (loss) attributable to owners		7,382,000,000		13,809,000,000
Comprehensive income (loss) attributable to owners		₩ 25,267,000,000		₩ (15,252,000,000)
AO Woori Bank
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		AO Woori Bank		AO Woori Bank
Main business		Finance		Finance
Percentage of ownership		100.00%		100.00%
Location		Russia		Russia
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 277,555,000,000		₩ 201,704,000,000
Liabilities		224,860,000,000		149,101,000,000
Operating revenue		8,778,000,000		15,656,000,000
Net income (loss) attributable to owners		2,570,000,000		4,748,000,000
Comprehensive income (loss) attributable to owners		₩ 200,000,000		₩ 1,217,000,000
PT Bank Woori Saudara Indonesia 1906 Tbk
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		PT Bank Woori Saudara Indonesia 1906 Tbk		PT Bank Woori Saudara Indonesia 1906 Tbk
Main business		Finance		Finance
Percentage of ownership		79.90%		79.90%
Location		Indonesia		Indonesia
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 2,349,222,000,000		₩ 2,230,617,000,000
Liabilities		1,858,176,000,000		1,745,171,000,000
Operating revenue		96,177,000,000		192,485,000,000
Net income (loss) attributable to owners		22,401,000,000		38,488,000,000
Comprehensive income (loss) attributable to owners		₩ 15,947,000,000		₩ (18,689,000,000)
Banco Woori Bank do Brasil S.A
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Banco Woori Bank do Brasil S.A.		Banco Woori Bank do Brasil S.A.
Main business		Finance		Finance
Percentage of ownership		100.00%		100.00%
Location		Brazil		Brazil
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 155,083,000,000		₩ 213,889,000,000
Liabilities		125,288,000,000		181,544,000,000
Operating revenue		7,341,000,000		20,455,000,000
Net income (loss) attributable to owners		882,000,000		1,843,000,000
Comprehensive income (loss) attributable to owners		₩ (2,515,000,000)		₩ (2,840,000,000)
Korea BTL Infrastructure Fund
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Korea BTL Infrastructure Fund		Korea BTL Infrastructure Fund
Main business		Finance		Finance
Percentage of ownership		99.90%		99.90%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 777,576,000,000		₩ 786,480,000,000
Liabilities		297,000,000		301,000,000
Operating revenue		14,704,000,000		30,240,000,000
Net income (loss) attributable to owners		12,865,000,000		26,390,000,000
Comprehensive income (loss) attributable to owners		₩ 12,865,000,000		₩ 26,390,000,000
Woori Fund Service Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori Fund Service Co., Ltd.		Woori Fund Service Co., Ltd.
Main business		Finance		Finance
Percentage of ownership		100.00%		100.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 13,411,000,000		₩ 12,653,000,000
Liabilities		977,000,000		1,242,000,000
Operating revenue		4,922,000,000		9,021,000,000
Net income (loss) attributable to owners		1,023,000,000		1,398,000,000
Comprehensive income (loss) attributable to owners		₩ 1,023,000,000		₩ 1,398,000,000
Woori Finance Cambodia PLC
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori Finance Cambodia PLC.		Woori Finance Cambodia PLC.
Main business		Finance		Finance
Percentage of ownership		100.00%		100.00%
Location		Cambodia		Cambodia
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 73,212,000,000		₩ 51,304,000,000
Liabilities		52,584,000,000		32,873,000,000
Operating revenue		4,912,000,000		5,895,000,000
Net income (loss) attributable to owners		1,277,000,000		983,000,000
Comprehensive income (loss) attributable to owners		₩ 2,197,000,000		₩ (473,000,000)
Woori Finance Myanmar Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori Finance Myanmar Co., Ltd.		Woori Finance Myanmar Co., Ltd.
Main business		Finance		Finance
Percentage of ownership		100.00%		100.00%
Location		Myanmar		Myanmar
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 19,837,000,000		₩ 18,236,000,000
Liabilities		6,496,000,000		5,307,000,000
Operating revenue		2,086,000,000		2,506,000,000
Net income (loss) attributable to owners		(187,000,000)		791,000,000
Comprehensive income (loss) attributable to owners		₩ 412,000,000		₩ 15,000,000
Wealth Development Bank
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Wealth Development Bank		Wealth Development Bank
Main business		Finance		Finance
Percentage of ownership		51.00%		51.00%
Location		Philippines		Philippines
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 185,866,000,000		₩ 191,049,000,000
Liabilities		152,414,000,000		156,808,000,000
Operating revenue		6,240,000,000		13,632,000,000
Net income (loss) attributable to owners		(2,000,000)		1,323,000,000
Comprehensive income (loss) attributable to owners		₩ (788,000,000)		₩ (1,093,000,000)
Woori Bank Vietnam Limited
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori Bank Vietnam Limited		Woori Bank Vietnam Limited
Main business		Finance		Finance
Percentage of ownership		100.00%		100.00%
Location		Vietnam		Vietnam
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 1,142,018,000,000		₩ 775,758,000,000
Liabilities		990,228,000,000		632,160,000,000
Operating revenue		23,746,000,000		29,698,000,000
Net income (loss) attributable to owners		3,545,000,000		2,436,000,000
Comprehensive income (loss) attributable to owners		₩ 8,822,000,000		₩ (15,347,000,000)
WB Finance Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank
Subsidiaries		WB Finance Co., Ltd.
Main business		Finance
Percentage of ownership		100.00%
Location		Cambodia
Date of Financial statements		Jun. 30, 2018
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		₩ 227,582,000,000
Liabilities		186,772,000,000
Operating revenue		0
Net income (loss) attributable to owners		0
Comprehensive income (loss) attributable to owners		₩ 0
Kumho Trust First Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Kumho Trust First Co., Ltd.		Kumho Trust First Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Asiana Saigon Inc
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Asiana Saigon Inc.		Asiana Saigon Inc.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Consus Eighth Co LLC
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Consus Eighth Co., LLC		Consus Eighth Co., LLC
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
KAMCO Value Recreation First Securitization Specialty Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		KAMCO Value Recreation First Securitization Specialty Co., Ltd.		KAMCO Value Recreation First Securitization Specialty Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		15.00%		15.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Hermes STX Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Hermes STX Co., Ltd.		Hermes STX Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
BWL First Co LLC
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		BWL First Co., LLC		BWL First Co., LLC
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Deogi Dream Fourth Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Deogi Dream Fourth Co., Ltd.		Deogi Dream Fourth Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Jeonju Iwon Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Jeonju Iwon Ltd.		Jeonju Iwon Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Wonju I one Inc
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Wonju I one Inc.		Wonju I one Inc.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Heitz Third Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Heitz Third Co., Ltd.		Heitz Third Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Woorihansoop First Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woorihansoop 1st Co., Ltd.		Woorihansoop 1st Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Electric Cable First Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Electric Cable First Co., Ltd		Electric Cable First Co., Ltd
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Woori International First Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori International First Co., Ltd.		Woori International First Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Woori HJ First Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori HJ First Co., Ltd.		Woori HJ First Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Woori WEBST First Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori WEBST 1st Co., Ltd.		Woori WEBST 1st Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Wibihansoop First Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Wibihansoop 1st Co., Ltd.		Wibihansoop 1st Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
HNLD First Inc
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		HNLD 1st Inc.		HNLD 1st Inc.
Main business		Asset securitization		Asset securitization
Percentage of ownership				0.00%
Location		Korea		Korea
Description of reason why entityIs not subsidiary due to absence of control	[2]	The entity is a structured entity for the purpose of asset securitization and is not in scope for consolidation considering that the Group 1) does not have the power over the investee, 2) is not exposed, or does not have rights to variable returns from its involvement with the investee, and 3) does not have the ability to use its power to affect its returns.		The entity is a structured entity for the purpose of asset securitization and is not in scope for consolidation considering that the Group 1) does not have the power over the investee, 2) is not exposed, or does not have rights to variable returns from its involvement with the investee, and 3) does not have the ability to use its power to affect its returns.
Uri QS First Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Uri QS 1st Co., Ltd		Uri QS 1st Co., Ltd
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Uri Display First Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Uri Display 1st Co., Ltd.		Uri Display 1st Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Tiger Eyes Second Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Tiger Eyes 2nd Co., Ltd.		Tiger Eyes 2nd Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Woori Serveone First Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Woori Serveone 1st Co., Ltd.		Woori Serveone 1st Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Uri Display 2nd Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank
Subsidiaries		Uri Display 2nd Co.,Ltd.
Main business		Asset securitization
Percentage of ownership		0.00%
Location		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Woori the Colony Unjung Securitization Specialty Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank
Subsidiaries		Woori the Colony Unjung Securitization Specialty Co., Ltd.
Main business		Asset securitization
Percentage of ownership		0.00%
Location		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Woori Dream 1st Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank
Subsidiaries		Woori Dream 1st Co., Ltd.
Main business		Asset securitization
Percentage of ownership		0.00%
Location		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Woori HS 1st Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank
Subsidiaries		Woori HS 1st Co., Ltd.
Main business		Asset securitization
Percentage of ownership		0.00%
Location		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Smart Casting Inc
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank
Subsidiaries		Smart Casting Inc.
Main business		Asset securitization
Percentage of ownership		0.00%
Location		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
HeungkukWoori Tech Company Private Placement Investment Trust No.1 and 6 beneficiary certificates
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank
Subsidiaries		HeungkukWoori Tech Company Private Placement Investment Trust No. 1 and 6 beneficiary certificates
Main business		Securities investment and others
Location		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[3]	The entity was a structured entity for the purpose of investment in securities and was in scope for consolidation, considering that the Group 1) had the power over the investee, 2) was exposed, or has rights, to variable returns from its involvement with the investee, and 3) has the ability to use its power to affect its returns.
Principle Guaranteed Trust
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Principle Guaranteed Trust		Principle Guaranteed Trust
Main business		Trust		Trust
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power		The entity was a money trust under the Financial Investment Services and Capital Markets Act and was in scope for consolidation. Although the Group was not a majority shareholder, the Group 1) has the power over the investee, 2) was exposed, or has rights, to variable returns from its involvement with the investee, and 3) has the ability to use its power to affect its returns.	[4]	The entity was a money trust under the Financial Investment Services and Capital Markets Act and was in scope for consolidation. Although the Group was not a majority shareholder, the Group 1) has the power over the investee, 2) was exposed, or has rights, to variable returns from its involvement with the investee, and 3) has the ability to use its power to affect its returns.
Principle and Interest Guaranteed Trust
Significant investments in subsidiaries [Abstract]
Investor		Woori Bank		Woori Bank
Subsidiaries		Principle and Interest Guaranteed Trust		Principle and Interest Guaranteed Trust
Main business		Trust		Trust
Percentage of ownership		0.00%		0.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power		The entity was a money trust under the Financial Investment Services and Capital Markets Act and was in scope for consolidation. Although the Group was not a majority shareholder, the Group 1) has the power over the investee, 2) was exposed, or has rights, to variable returns from its involvement with the investee, and 3) has the ability to use its power to affect its returns.	[4]	The entity was a money trust under the Financial Investment Services and Capital Markets Act and was in scope for consolidation. Although the Group was not a majority shareholder, the Group 1) has the power over the investee, 2) was exposed, or has rights, to variable returns from its involvement with the investee, and 3) has the ability to use its power to affect its returns.
Dongwoo First Securitization Specialty Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Investment Bank		Woori Investment Bank
Subsidiaries		Dongwoo First Securitization Specialty Co., Ltd.		Dongwoo First Securitization Specialty Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		5.00%		5.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Seari First Securitization Specialty Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Investment Bank		Woori Investment Bank
Subsidiaries		Seari First Securitization Specialty Co., Ltd.		Seari First Securitization Specialty Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		5.00%		5.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Namjong First Securitization Specialty Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Investment Bank		Woori Investment Bank
Subsidiaries		Namjong 1st Securitization Specialty Co., Ltd.		Namjong 1st Securitization Specialty Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		5.00%		5.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Bukgeum First Securitization Specialty Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Investment Bank		Woori Investment Bank
Subsidiaries		Bukgeum First Securitization Specialty Co., Ltd.		Bukgeum First Securitization Specialty Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		5.00%		5.00%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Seari Second Securitization Specialty Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Investment Bank
Subsidiaries		Seori Second Securitization Specialty Co., Ltd.
Main business		Asset securitization
Percentage of ownership		5.00%
Location		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Bukgeum Second Securitization Specialty Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Investment Bank
Subsidiaries		Bukgeum Second Securitization Specialty Co., Ltd.
Main business		Asset securitization
Percentage of ownership		5.00%
Location		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
TUTU FinanceWCI Myanmar Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Card Co., Ltd.		Woori Card Co., Ltd.
Subsidiaries		TUTU Finance-WCI Myanmar Co., Ltd.		TUTU Finance-WCI Myanmar Co., Ltd.
Main business		Finance		Finance
Percentage of ownership		100.00%		100.00%
Location		Myanmar		Myanmar
Date of Financial statements		Jun. 30, 2018
Woori Card one of 2017-1 Securitization Specialty Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Card Co., Ltd.		Woori Card Co., Ltd.
Subsidiaries		Woori Card one of 2017-1 Securitization Specialty Co., Ltd.		Woori Card one of 2017-1 Securitization Specialty Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.50%		0.50%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Woori Card one of 2017-2 Securitization Specialty Co Ltd
Significant investments in subsidiaries [Abstract]
Investor		Woori Card Co., Ltd.		Woori Card Co., Ltd.
Subsidiaries		Woori Card one of 2017-2 Securitization Specialty Co., Ltd.		Woori Card one of 2017-2 Securitization Specialty Co., Ltd.
Main business		Asset securitization		Asset securitization
Percentage of ownership		0.50%		0.50%
Location		Korea		Korea
Date of Financial statements		Jun. 30, 2018
Description of nature of relationship with subsidiary where parent has directly or indirectly less than half of voting power	[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.		The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
Money trust under the FISCM Act
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets	[5]	₩ 1,573,367,000,000		₩ 1,560,672,000,000
Liabilities	[5]	1,543,491,000,000		1,530,760,000,000
Operating revenue	[5]	24,029,000,000		44,344,000,000
Net income (loss) attributable to owners	[5]	(36,000,000)		582,000,000
Comprehensive income (loss) attributable to owners	[5]	(36,000,000)		582,000,000
Structured entity for the securitization of financial assets
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		1,226,022,000,000		867,583,000,000
Liabilities		1,631,837,000,000		1,275,719,000,000
Operating revenue		32,089,000,000		22,730,000,000
Net income (loss) attributable to owners		12,202,000,000		1,179,000,000
Comprehensive income (loss) attributable to owners		5,725,000,000		(2,800,000,000)
Security investments structured entity
Disclosure of condensed financial information of significant investments in subsidiaries [Abstract]
Assets		41,221,000,000		34,939,000,000
Liabilities		40,000,000		76,000,000
Operating revenue		785,000,000		377,000,000
Net income (loss) attributable to owners		(798,000,000)		(475,000,000)
Comprehensive income (loss) attributable to owners		₩ (1,869,000,000)		₩ (38,592,000,000)
[1]	The entity was a structured entity for the purpose of asset securitization and was in scope for consolidation. Although the Group is not a majority shareholder, the Group 1) had the power over the investee, 2) was exposed, or had rights, to variable returns from its involvement with the investee, and 3) had the ability to use its power to affect its returns.
[2]	The entity is a structured entity for the purpose of asset securitization and is not in scope for consolidation considering that the Group 1) does not have the power over the investee, 2) is not exposed, or does not have rights to variable returns from its involvement with the investee, and 3) does not have the ability to use its power to affect its returns.
[3]	The entity was a structured entity for the purpose of investment in securities and was in scope for consolidation, considering that the Group 1) had the power over the investee, 2) was exposed, or has rights, to variable returns from its involvement with the investee, and 3) has the ability to use its power to affect its returns.
[4]	The entity was a money trust under the Financial Investment Services and Capital Markets Act and was in scope for consolidation. Although the Group was not a majority shareholder, the Group 1) has the power over the investee, 2) was exposed, or has rights, to variable returns from its involvement with the investee, and 3) has the ability to use its power to affect its returns.
[5]	FISCM Act: Financial Investment Services and Capital Markets Act

General_Unconsolidated companie

General_Unconsolidated companies with more than 50 Percent ownership interests (Details)		6 Months Ended		12 Months Ended
		Jun. 30, 2018		Dec. 31, 2017
Golden Bridge NHN Online Private Equity Investment
Disclosure of information about unconsolidated subsidiaries [Line Items]
Name of subsidiary		Golden Bridge NHN Online Private Equity Investment	[1]	Golden Bridge NHN Online Private Equity Investment
Location		Korea		Korea
Main business		Securities Investment		Securities Investment
Percentage of ownership		60.00%		60.00%
Description of reason why entity with more than half of voting power directly or indirectly owned which is not subsidiary due to absence of control	[1]	The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.		The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.
Mirae Asset Maps Clean Water Private Equity Investment Trust Seventh
Disclosure of information about unconsolidated subsidiaries [Line Items]
Name of subsidiary		Mirae Asset Maps Clean Water Private Equity Investment Trust 7th	[1]	Mirae Asset Maps Clean Water Private Equity Investment Trust 7th
Location		Korea		Korea
Main business		Securities Investment		Securities Investment
Percentage of ownership		57.10%		59.70%
Description of reason why entity with more than half of voting power directly or indirectly owned which is not subsidiary due to absence of control	[1]	The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.		The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.
Kiwoom Yonsei Private Equity Investment Trust
Disclosure of information about unconsolidated subsidiaries [Line Items]
Name of subsidiary		Kiwoom Yonsei Private Equity Investment Trust	[1]	Kiwoom Yonsei Private Equity Investment Trust
Location		Korea		Korea
Main business		Securities Investment		Securities Investment
Percentage of ownership		88.30%		88.90%
Description of reason why entity with more than half of voting power directly or indirectly owned which is not subsidiary due to absence of control	[1]	The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.		The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.
Hana Walmart Real Estate Investment Trust 41-1
Disclosure of information about unconsolidated subsidiaries [Line Items]
Name of subsidiary		Hana Walmart Real Estate Investment Trust 41-1	[1]	Hana Walmart Real Estate Investment Trust 41-1
Location		Korea		Korea
Main business		Securities Investment		Securities Investment
Percentage of ownership		77.00%		90.10%
Description of reason why entity with more than half of voting power directly or indirectly owned which is not subsidiary due to absence of control	[1]	The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.		The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.
IGIS Global Private Placement Real Estate Fund No. 148-1
Disclosure of information about unconsolidated subsidiaries [Line Items]
Name of subsidiary		IGIS Global Private Placement Real Estate Fund No. 148-1	[1]	IGIS Global Private Placement Real Estate Fund No. 148-1
Location		Korea		Korea
Main business		Securities Investment		Securities Investment
Percentage of ownership		75.00%		75.00%
Description of reason why entity with more than half of voting power directly or indirectly owned which is not subsidiary due to absence of control	[1]	The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.		The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.
IGIS Global Private Placement Real Estate Fund No. 148-2
Disclosure of information about unconsolidated subsidiaries [Line Items]
Name of subsidiary		IGIS Global Private Placement Real Estate Fund No. 148-2	[1]	IGIS Global Private Placement Real Estate Fund No. 148-2
Location		Korea		Korea
Main business		Securities Investment		Securities Investment
Percentage of ownership		75.00%		75.00%
Description of reason why entity with more than half of voting power directly or indirectly owned which is not subsidiary due to absence of control	[1]	The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.		The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.
Mirae Asset Seoul Ring Expresway Private Special Asset Fund I
Disclosure of information about unconsolidated subsidiaries [Line Items]
Name of subsidiary	[1]	Mirae Asset Seoul Ring Expressway Private Special Asset Fund I
Location		Korea
Main business		Securities Investment
Percentage of ownership		66.20%
Description of reason why entity with more than half of voting power directly or indirectly owned which is not subsidiary due to absence of control	[1]	The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.
Hangkang Sewage Treament Plant Fund
Disclosure of information about unconsolidated subsidiaries [Line Items]
Name of subsidiary	[1]	Hangkang Sewage Treatment Plant Fund
Location		Korea
Main business		Securities Investment
Percentage of ownership		55.60%
Description of reason why entity with more than half of voting power directly or indirectly owned which is not subsidiary due to absence of control	[1]	The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.
Consus KyungJu Green Private Placement Real Estate Fund 1st
Disclosure of information about unconsolidated subsidiaries [Line Items]
Name of subsidiary	[1]	Consus KyungJu Green Private Placement Real Estate Fund 1st
Location		Korea
Main business		Securities Investment
Percentage of ownership		52.40%
Description of reason why entity with more than half of voting power directly or indirectly owned which is not subsidiary due to absence of control	[1]	The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.
[1]	The Group owns the majority ownership interest in these structured entities, but has no power on the investees’ relevant activities. As results, it is deemed that the Group has no power or control on the structured entities.

General_Limitations on transfer

General_Limitations on transfer of assets or the redemption of liabilities within the Group (Details)	6 Months Ended
	Jun. 30, 2018
Consolidated structured entities [Member]
Disclosure of information about consolidated structured entities [Line Items]
Description of intentions to provide support to structured entity	The Group is providing purchase commitment and credit facilities to structured entities that are subsidiaries of the Group. Purchase commitments guarantee the purchase and payment of outstanding commercial papers that were issued but were not repurchased by the structured entities. Credit facilities allow lending of funds to structured entities under certain conditions when there are grounds for discontinuing the issuance of commercial papers, or when structured entities default due to some reasons. As of June 30, 2018, the Group is providing credit facilities (including ABCP purchase commitments, etc.) amounting to 1,156,431 million Won to aforementioned structured entities.
Structured entity for the securitization of financial assets
Disclosure of information about consolidated structured entities [Line Items]
Description of terms of contractual arrangements that could require parent or subsidiaries to provide financial support to structured entity	The structured entity is established for the purpose of securitization of project financing loans, corporate bonds, and other financial assets. The Group is involved with the structured entity through providing with credit facility over asset-backed commercial papers issued by the entity, originating loans directly to the structured entity, or purchasing 100% of the subordinated debts issued by the structured entity.
Structured entity for the investments in securities
Disclosure of information about consolidated structured entities [Line Items]
Description of terms of contractual arrangements that could require parent or subsidiaries to provide financial support to structured entity	The structured entity is established for the purpose of investments in securities. The Group acquires beneficiary certificates through its contribution of fund to the structured entity, and it is exposed to the risk that it may not be able to recover its fund depending on the result of investment performance of asset managers of the structured entity.
Money trust under the Financial Investment Services and Capital Markets Act
Disclosure of information about consolidated structured entities [Line Items]
Description of terms of contractual arrangements that could require parent or subsidiaries to provide financial support to structured entity	The Group provides with financial guarantee of principal and interest or principal only to some of its trust products. Due to the financial guarantees, the Group may be obliged to supplement when the principal and interest or principal of the trust product sold is short of the guaranteed amount depending on the result of investment performance of the trust product.

General_Financial informations

General_Financial informations Maximum exposure and Loss recognised of unconsolidated structured entities (Details) - KRW (₩)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Asset securitization vehicle
Disclosure of unconsolidated structured entities [Line Items]
The maximum exposure to risks	₩ 3,697,522,000,000	₩ 4,032,531,000,000
Investments	2,956,395,000,000	3,215,159,000,000
Credit facilities	741,127,000,000	817,372,000,000
Loss recognized on unconsolidated structured entities	₩ 158,000,000	₩ 837,000,000
Disclosure of information about interests in structured entity	Asset securitization vehicle issues asset-backed securities and redeems the principal and interest or distributes dividends on asset-backed securities with profits from collecting cash flows or sale of securitized assets. The Group, as a secondary guarantor, provides purchase commitments for its asset-backed securities or guarantees to such asset securitization vehicle and recognizes commission income or interest income related to the commitment or guarantees. Therefore, the Group would be exposed to risks to purchases or pays back asset-backed securities issued by the vehicles when a primary guarantor fails to provide the financing asset securitization vehicles.	Asset securitization vehicle issues asset-backed securities and redeems the principal and interest or distributes dividends on asset-backed securities with profits from collecting cash flows or sale of securitized assets. The Group, as a secondary guarantor, provides purchase commitments for its asset-backed securities or guarantees to such asset securitization vehicle and recognizes commission income or interest income related to the commitment or guarantees. Therefore, the Group would be exposed to risks to purchases or pays back asset-backed securities issued by the vehicles when a primary guarantor fails to provide the financing asset securitization vehicles.
Asset securitization vehicle | Classes of assets [Domain]
Disclosure of unconsolidated structured entities [Line Items]
Total asset of the unconsolidated structured entities	₩ 7,955,990,000,000	₩ 7,295,601,000,000
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	2,956,395,000,000	3,215,159,000,000
Asset securitization vehicle | Financial assets at FVTPL (IFRS 9)
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	232,931,000,000
Asset securitization vehicle | Financial assets at FVTOCI
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	499,861,000,000
Asset securitization vehicle | Financial assets at amortized cost
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	2,223,211,000,000
Asset securitization vehicle | Loans and receivables
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities		43,180,000,000
Asset securitization vehicle | Financial assets held for trading
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities		0
Asset securitization vehicle | Available-for-sale financial assets
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities		902,390,000,000
Asset securitization vehicle | Held-to-maturity financial assets
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities		2,269,451,000,000
Asset securitization vehicle | Investments in joint ventures and associates
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	0	0
Asset securitization vehicle | Derivative assets
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	392,000,000	138,000,000
Asset securitization vehicle | Liabilities [Domain]
Disclosure of unconsolidated structured entities [Line Items]
Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities	1,442,000,000	1,433,000,000
Asset securitization vehicle | Derivative liabilities
Disclosure of unconsolidated structured entities [Line Items]
Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities	361,000,000	575,000,000
Asset securitization vehicle | Other liabilities (including provisions)
Disclosure of unconsolidated structured entities [Line Items]
Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities	1,081,000,000	858,000,000
Structured finance
Disclosure of unconsolidated structured entities [Line Items]
The maximum exposure to risks	2,818,678,000,000	2,918,448,000,000
Investments	2,162,493,000,000	2,314,043,000,000
Credit facilities	656,185,000,000	604,405,000,000
Loss recognized on unconsolidated structured entities	₩ 8,757,000,000	₩ 3,939,000,000
Disclosure of information about interests in structured entity	Structured finance includes investments in project financing on real estates, social overhead capital (“SOC”), infrastructure and shipping finance. They are formed as special purpose entity by funding through equity investments and loans from various investors. Investment decisions are made by the Group based on business outlook of such projects. In relation to such investments, the Group recognizes interest income on loans, gains or losses on valuation of equity investments or dividend income. The structured finance is secured by additional funding agreement, guarantee or credit facilities. However, the structured financing project would fail to return the capital of equity investments or principal of loans to the Group if it is discontinued or did not achieve business outcome.	Structured finance includes investments in project financing on real estates, social overhead capital (“SOC”), infrastructure and shipping finance. They are formed as special purpose entity by funding through equity investments and loans from various investors. Investment decisions are made by the Group based on business outlook of such projects. In relation to such investments, the Group recognizes interest income on loans, gains or losses on valuation of equity investments or dividend income. The structured finance is secured by additional funding agreement, guarantee or credit facilities. However, the structured financing project would fail to return the capital of equity investments or principal of loans to the Group if it is discontinued or did not achieve business outcome.
Structured finance | Classes of assets [Domain]
Disclosure of unconsolidated structured entities [Line Items]
Total asset of the unconsolidated structured entities	₩ 36,949,944,000,000	₩ 40,172,830,000,000
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	2,162,493,000,000	2,314,043,000,000
Structured finance | Financial assets at FVTPL (IFRS 9)
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	69,259,000,000
Structured finance | Financial assets at FVTOCI
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	49,538,000,000
Structured finance | Financial assets at amortized cost
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	2,039,184,000,000
Structured finance | Loans and receivables
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities		1,969,760,000,000
Structured finance | Financial assets held for trading
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities		233,428,000,000
Structured finance | Available-for-sale financial assets
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities		106,819,000,000
Structured finance | Held-to-maturity financial assets
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities		0
Structured finance | Investments in joint ventures and associates
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	885,000,000	0
Structured finance | Derivative assets
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	3,627,000,000	4,036,000,000
Structured finance | Liabilities [Domain]
Disclosure of unconsolidated structured entities [Line Items]
Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities	1,587,000,000	1,506,000,000
Structured finance | Derivative liabilities
Disclosure of unconsolidated structured entities [Line Items]
Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities	749,000,000	968,000,000
Structured finance | Other liabilities (including provisions)
Disclosure of unconsolidated structured entities [Line Items]
Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities	838,000,000	538,000,000
Investment Funds
Disclosure of unconsolidated structured entities [Line Items]
The maximum exposure to risks	1,398,067,000,000	1,138,523,000,000
Investments	1,333,612,000,000	1,138,523,000,000
Credit facilities	64,455,000,000	0
Loss recognized on unconsolidated structured entities	₩ 9,110,000,000	₩ 5,993,000,000
Disclosure of information about interests in structured entity	Investment funds include trusts and private equity funds. A trust is formed by contributions from various investors, operated by a manager engaged to the trust and distributed proceeds from sales of investments to the investors. A private equity fund is established in order to acquire ownership interests in a portfolio company with exit strategy after implementing financial and operational restructuring of the company. The Group recognizes unrealized gains or losses on change in value of investments in proposition of ownership interests in investments. The Group would be exposed to risks of loss when the value of portfolio investment is decreased.	Investment funds include trusts and private equity funds. A trust is formed by contributions from various investors, operated by a manager engaged to the trust and distributed proceeds from sales of investments to the investors. A private equity fund is established in order to acquire ownership interests in a portfolio company with exit strategy after implementing financial and operational restructuring of the company. The Group recognizes unrealized gains or losses on change in value of investments in proposition of ownership interests in investments. The Group would be exposed to risks of loss when the value of portfolio investment is decreased.
Investment Funds | Classes of assets [Domain]
Disclosure of unconsolidated structured entities [Line Items]
Total asset of the unconsolidated structured entities	₩ 14,777,372,000,000	₩ 13,641,135,000,000
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	1,333,612,000,000	1,138,523,000,000
Investment Funds | Financial assets at FVTPL (IFRS 9)
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	1,079,544,000,000
Investment Funds | Financial assets at FVTOCI
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	0
Investment Funds | Financial assets at amortized cost
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	10,697,000,000
Investment Funds | Loans and receivables
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities		0
Investment Funds | Financial assets held for trading
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities		10,160,000,000
Investment Funds | Available-for-sale financial assets
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities		904,774,000,000
Investment Funds | Held-to-maturity financial assets
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities		0
Investment Funds | Investments in joint ventures and associates
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	243,371,000,000	223,589,000,000
Investment Funds | Derivative assets
Disclosure of unconsolidated structured entities [Line Items]
Assets recognized in the consolidated financial statements related to the unconsolidated structured entities	0	0
Investment Funds | Liabilities [Domain]
Disclosure of unconsolidated structured entities [Line Items]
Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities	81,000,000	0
Investment Funds | Derivative liabilities
Disclosure of unconsolidated structured entities [Line Items]
Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities	0	0
Investment Funds | Other liabilities (including provisions)
Disclosure of unconsolidated structured entities [Line Items]
Liabilities recognized in the consolidated financial statements related to the unconsolidated structured entities	₩ 81,000,000	₩ 0

General_Noncontrolling interest

General_Noncontrolling interests (Details) - KRW (₩) ₩ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Woori Investment Bank
Disclosure of significant investments in subsidiaries [Line Items]
Accumulated non-controlling interests	₩ 125,809		₩ 119,111
Net income attributable to non-controlling interests	5,912	₩ 5,072
PT Bank Woori Saudara Indonesia 1906 Tbk
Disclosure of significant investments in subsidiaries [Line Items]
Accumulated non-controlling interests	66,004		64,877
Net income attributable to non-controlling interests	4,508	5,048
Dividends to non-controlling interests	2,082	1,513
Wealth Development Bank
Disclosure of significant investments in subsidiaries [Line Items]
Accumulated non-controlling interests	16,391		₩ 16,778
Net income attributable to non-controlling interests	₩ (1)	₩ 515

Basis of preparation and sig103

Basis of preparation and significant accounting policies_Basis of presentation (Details)	6 Months Ended
	Jun. 30, 2018
Accounting policies [Abstract]
Description of accounting policies and methods of computation followed in interim financial statements	Unless stated below, the accounting policies applied in preparing the accompanying consolidated interim financial statements have been applied consistently with the annual consolidated financial statements as of and for the year ended December 31, 2017.
Description of compliance with IFRSs if applied for interim financial report	The Group’s consolidated interim financial statements are prepared in accordance with International Financial Reporting Standards (“IFRS”) 34, Interim Financial Reporting and IFRS 10, Consolidated Financial Statements. It is necessary to use the annual consolidated financial statements for the year ended December 31, 2017 for understanding of the accompanying interim financial statements.

Basis of preparation and sig104

Basis of preparation and significant accounting policies_The adoption of IFRS 9 and other standards related to IFRS 9 and the effect (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Disclosure of initial application of standards or interpretations [Line Items]
Title of initially applied IFRS
Adoption of IFRS 9 – Financial instruments (enacted)
Disclosure of initial application of standards or interpretations [Line Items]
Title of initially applied IFRS		Financial instruments
Description whether change in accounting policy is made in accordance with transitional provisions of initially applied IFRS		The Group applied for the first time as of January 1, 2018, the adoption to IFRS 9 and other standards related to IFRS 9, which introduces new rules: 1) classification and measurement of financial assets and financial liabilities, 2) impairment of financial assets, and 3) hedge accounting.
Description of nature of change in accounting policy		All financial assets included in the scope of IFRS 9 are subsequently measured at amortized cost or fair value based on the business model for the management of financial assets and the nature of the contractual cash flows.
Description of how and from when changes in accounting policies have been applied		The Group decided not to restate the prior period figures when applying the Standard for the first time, thus the comparative financial statements presented are not restated.
Adoption of IFRS 15 – Revenue from contracts with customers (enacted)
Disclosure of initial application of standards or interpretations [Line Items]
Title of initially applied IFRS		Revenue from contracts with customers
Description whether change in accounting policy is made in accordance with transitional provisions of initially applied IFRS		The Group adopted IFRS 15 for the first time and decided to retrospectively apply the cumulative effect of the first application of IFRS 15 as of January 1, 2018.
Description of how and from when changes in accounting policies have been applied		The Group decided not to restate the prior periods when applying IFRS 15 for the first time. Accordingly, the Group has not retroactively restated the comparative consolidated financial statements presented herein.
Amendments to IFRS 2 – Classification and Measurement of Share-based Payment Transactions
Disclosure of initial application of standards or interpretations [Line Items]
Title of initially applied IFRS		Classification and Measurement of Share-based Payment Transactions
Description of nature of change in accounting policy		The amendments clarify the following; i) In estimating the fair value of a cash-settled share-based payment, the accounting for the effects of vesting and non-vesting conditions should follow the same approach as for equity-settled share-based payments ii) Where tax law or regulation requires an entity to withhold a specified number of equity instruments equal to the monetary value of the employee’s tax obligation to meet the employee’s tax liability which is then remitted to the tax authority, i.e. the share-based payment arrangement has a ‘net settlement feature’, such an arrangement should be classified as equity-settled in its entirety, provided that the share-based payment would have been classified as equity-settled had it not included the net settlement feature, iii) A modification of a share-based payment that changes the transaction from cash-settled to equity-settled should be accounted for as follows; a) the original liability is derecognized; b) the equity-settled share-based payment is recognized at the modification date fair value of the equity instrument granted to the extent that services have been rendered up to the modification date; and c) any difference between the carrying amount of the liability at the modification date and the amount recognized in equity should be recognized in profit or loss immediately.
Amendments to IAS 40 – Transfers of Investment Property
Disclosure of initial application of standards or interpretations [Line Items]
Title of initially applied IFRS		Transfers of Investment Property
Description of nature of change in accounting policy		The amendments clarify that a transfer to, or from, investment property necessitates an assessment of whether a property meets the definition of investment property, supported by observable evidence that a change in use has occurred. The amendments further clarify that the situations listed in IAS 40 are not exhaustive and that a change in use is possible for properties under construction (i.e. a change in use is not limited to completed properties).
Amendments to IFRIC 22 – Foreign Currency Transactions and Advance Consideration
Disclosure of initial application of standards or interpretations [Line Items]
Title of initially applied IFRS		Foreign Currency Transactions and Advance Consideration
Description of nature of change in accounting policy		IFRIC 22 addresses how to determine the ‘date of transaction’ for the purpose of determining the exchange rate to use on initial recognition of an asset, expense or income (or part of them), when consideration for that item has been paid or received in advance in a foreign currency which resulted in the recognition of a non-monetary asset or non-monetary liability (e.g. a non-refundable deposit or deferred revenue).
Annual Improvements to IFRS 2014-2016 Cycle
Disclosure of initial application of standards or interpretations [Line Items]
Description of nature of change in accounting policy		The amendments include partial amendments to IFRS 1 ‘First-time Adoption of IFRS’ and IAS 28 ‘Investments in Associates and Joint Ventures.’ Amendments to IAS 28 provide that an investment company such as a venture capital investment vehicle may selectively designate each of its investment in associates and/or joint ventures to be measured at fair value through profit or loss mandatorily measured at fair value, and that such designation must be made at the time of each investment’s initial recognition. In addition, when non-investment companies apply equity method to investment in associates and/or joint ventures that are investment companies, these companies may apply the same fair value measurement used by the said associates to value their own subsidiaries. This accounting treatment may be selectively applied to each associate.

Basis Of Preparation And Sig105

Basis Of Preparation And Significant accounting policies_Details of classification and measurement of financial assets in accordance with IFRS 9 and IAS 39 (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	₩ 306,941,042,000,000
Reclassification	0
Remeasurement	14,169,000,000
Classification according to IFRS 9	₩ 306,955,211,000,000
Deposit - Loans and receivables (IAS39) - Loan and other financial assets at amortized cost (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Loans and receivables
Classification according to IAS 39	₩ 8,870,835,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Loan and other financial assets at amortized cost
Classification according to IFRS 9	₩ 8,870,835,000,000
Debt securities - Available-for-sale financial assets (IAS39) - Securities at amortized cost (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Available-for-sale financial assets
Classification according to IAS 39	₩ 308,181,000,000
Reclassification	0
Remeasurement	₩ 14,119,000,000
Classification according to IFRS 9	Securities at amortized cost
Classification according to IFRS 9	₩ 322,300,000,000
Debt securities - Held to maturity financial assets (IAS39) - Securities at amortized cost (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Held to maturity financial assets
Classification according to IAS 39	₩ 16,749,296,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Securities at amortized cost
Classification according to IFRS 9	₩ 16,749,296,000,000
Loans - Loans and receivables (IAS39) - Loans and other financial assets at amortized cost (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Loans and receivables
Classification according to IAS 39	₩ 253,014,491,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Loan and other financial assets at amortized cost
Classification according to IFRS 9	₩ 253,014,491,000,000
Other financial assets - Loans and receivables (IAS39) - Loan and other financial assets at amortized cost (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Loans and receivables
Classification according to IAS 39	₩ 6,772,088,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Loan and other financial assets at amortized cost
Classification according to IFRS 9	₩ 6,772,088,000,000
Deposit - Financial assets at FVTPL (IAS39) - Financial assets at FVTPL (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Financial assets at FVTPL
Classification according to IAS 39	₩ 25,972,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial assets at FVTPL
Classification according to IFRS 9	₩ 25,972,000,000
Debt securities - Financial assets at FVTPL (IAS39) - Financial assets at FVTPL (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Financial assets at FVTPL
Classification according to IAS 39	₩ 2,654,027,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial assets at FVTPL	[1]
Classification according to IFRS 9	₩ 2,654,027,000,000
Description of reclassification and measurement of embedded derivatives out of hybrid financial instruments	Under IAS 39, the embedded derivatives out of hybrid financial instruments are accounted for as derivatives assets or liabilities if the criteria for separation of the embedded derivative are met and the rest of host contracts in those instruments are recorded as available-for-sale financial assets or loans and receivables respectively. Since IFRS 9 requires financial instruments be accounted for based on the terms of the entire financial instruments, the hybrid financial assets are revalued and recorded as financial assets at fair value through profit or loss.
Equity securities - Financial assets at FVTPL (IAS39) - Financial assets at FVTPL (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Financial assets at FVTPL
Classification according to IAS 39	₩ 47,304,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial assets at FVTPL	[1]
Classification according to IFRS 9	₩ 47,304,000,000
Description of reclassification and measurement of embedded derivatives out of hybrid financial instruments	Under IAS 39, the embedded derivatives out of hybrid financial instruments are accounted for as derivatives assets or liabilities if the criteria for separation of the embedded derivative are met and the rest of host contracts in those instruments are recorded as available-for-sale financial assets or loans and receivables respectively. Since IFRS 9 requires financial instruments be accounted for based on the terms of the entire financial instruments, the hybrid financial assets are revalued and recorded as financial assets at fair value through profit or loss.
Derivatives - Financial assets at FVTPL (IAS39) - Financial assets at FVTPL (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Financial assets at FVTPL
Classification according to IAS 39	₩ 3,115,775,000,000
Reclassification	(2,137,000,000)
Remeasurement	₩ 0
Classification according to IFRS 9	Financial assets at FVTPL	[1]
Classification according to IFRS 9	₩ 3,113,638,000,000
Description of reclassification and measurement of embedded derivatives out of hybrid financial instruments	Under IAS 39, the embedded derivatives out of hybrid financial instruments are accounted for as derivatives assets or liabilities if the criteria for separation of the embedded derivative are met and the rest of host contracts in those instruments are recorded as available-for-sale financial assets or loans and receivables respectively. Since IFRS 9 requires financial instruments be accounted for based on the terms of the entire financial instruments, the hybrid financial assets are revalued and recorded as financial assets at fair value through profit or loss.
Equity securities - Available-for-sale financial assets (IAS39) - Financial assets at FVTPL (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Available-for-sale financial assets
Classification according to IAS 39	₩ 1,273,498,000,000
Reclassification	1,219,000,000
Remeasurement	₩ 0
Classification according to IFRS 9	Financial assets at FVTPL	[1]
Classification according to IFRS 9	₩ 1,274,717,000,000
Description of reclassification and measurement of embedded derivatives out of hybrid financial instruments	Under IAS 39, the embedded derivatives out of hybrid financial instruments are accounted for as derivatives assets or liabilities if the criteria for separation of the embedded derivative are met and the rest of host contracts in those instruments are recorded as available-for-sale financial assets or loans and receivables respectively. Since IFRS 9 requires financial instruments be accounted for based on the terms of the entire financial instruments, the hybrid financial assets are revalued and recorded as financial assets at fair value through profit or loss.
Debt securities - Available-for-sale financial assets (IAS39) - Financial assets at FVTPL (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Available-for-sale financial assets
Classification according to IAS 39	₩ 46,855,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial assets at FVTPL
Classification according to IFRS 9	₩ 46,855,000,000
Loans - Loans and receivables (IAS39) - Financial assets at FVTPL (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Loans and receivables
Classification according to IAS 39	₩ 279,032,000,000
Reclassification	918,000,000
Remeasurement	₩ 50,000,000
Classification according to IFRS 9	Financial assets at FVTPL	[1]
Classification according to IFRS 9	₩ 280,000,000,000
Description of reclassification and measurement of embedded derivatives out of hybrid financial instruments	Under IAS 39, the embedded derivatives out of hybrid financial instruments are accounted for as derivatives assets or liabilities if the criteria for separation of the embedded derivative are met and the rest of host contracts in those instruments are recorded as available-for-sale financial assets or loans and receivables respectively. Since IFRS 9 requires financial instruments be accounted for based on the terms of the entire financial instruments, the hybrid financial assets are revalued and recorded as financial assets at fair value through profit or loss.
Derivatives
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Derivatives
Classification according to IAS 39	₩ 59,272,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Derivatives
Classification according to IFRS 9	₩ 59,272,000,000
Equity securities - Available-for-sale financial assets (IAS39) - Financial assets at FVTOCI (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Available-for-sale financial assets
Classification according to IAS 39	₩ 850,207,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial assets at FVTOCI
Classification according to IFRS 9	₩ 850,207,000,000
Debt securities - Available-for-sale financial assets (IAS39) - Financial assets at FVTOCI (IFRS9)
Disclosure of financial assets at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Available-for-sale financial assets
Classification according to IAS 39	₩ 12,874,209,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial assets at FVTOCI
Classification according to IFRS 9	₩ 12,874,209,000,000
[1]	Under IAS 39, the embedded derivatives out of hybrid financial instruments are accounted for as derivatives assets or liabilities if the criteria for separation of the embedded derivative are met and the rest of host contracts in those instruments are recorded as available-for-sale financial assets or loans and receivables respectively. Since IFRS 9 requires financial instruments be accounted for based on the terms of the entire financial instruments, the hybrid financial assets are revalued and recorded as financial assets at fair value through profit or loss.

Basis of preparation and sig106

Basis of preparation and significant accounting policies_Details of classification and measurement of financial liabilities in accordance with IFRS 9 and IAS 39 (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)
Disclosure of financial liabilities at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	₩ 294,809,262,000,000
Reclassification	0
Remeasurement	0
Classification according to IFRS 9	₩ 294,809,262,000,000
Deposit due to customers - Deposit due to customers (IAS39) - Financial liabilities at amortized cost (IFRS9)
Disclosure of financial liabilities at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Deposit due to customers
Classification according to IAS 39	₩ 234,695,084,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial liabilities at amortized cost
Classification according to IFRS 9	₩ 234,695,084,000,000
Borrowings - Borrowings (IAS39) - Financial liabilities at amortized cost (IFRS9)
Disclosure of financial liabilities at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Borrowings
Classification according to IAS 39	₩ 14,784,706,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial liabilities at amortized cost
Classification according to IFRS 9	₩ 14,784,706,000,000
Debentures - Debentures (IAS39) - Financial liabilities at amortized cost (IFRS9)
Disclosure of financial liabilities at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Debentures
Classification according to IAS 39	₩ 27,869,651,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial liabilities at amortized cost
Classification according to IFRS 9	₩ 27,869,651,000,000
Other financial liabilities - Other financial liabilities (IAS39) - Financial liabilities at amortized cost (IFRS9)
Disclosure of financial liabilities at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Other financial liabilities
Classification according to IAS 39	₩ 13,892,461,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial liabilities at amortized cost
Classification according to IFRS 9	₩ 13,892,461,000,000
Provision for financial guarantee - Provision for financial guarantee (IAS39) - Financial liabilities at amortized cost (IFRS9)
Disclosure of financial liabilities at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Provision for financial guarantee
Classification according to IAS 39	₩ 71,697,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial liabilities at amortized cost
Classification according to IFRS 9	₩ 71,697,000,000
Deposit due to customers - Financial liabilities at FVTPL (IAS39) - Financial liabilities at FVTPL (IFRS9)
Disclosure of financial liabilities at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Financial liabilities at FVTPL
Classification according to IAS 39	₩ 25,964,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial liabilities at FVTPL
Classification according to IFRS 9	₩ 25,964,000,000
Debentures - Financial liabilities at FVTPL (IAS39) - Financial liabilities at FVTPL (IFRS9)
Disclosure of financial liabilities at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Financial liabilities at FVTPL
Classification according to IAS 39	₩ 91,739,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial liabilities at FVTPL
Classification according to IFRS 9	₩ 91,739,000,000
Equity-linked securities - Financial liabilities at FVTPL (IAS39) - Financial liabilities at FVTPL (IFRS9)
Disclosure of financial liabilities at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Financial liabilities at FVTPL
Classification according to IAS 39	₩ 160,057,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial liabilities at FVTPL
Classification according to IFRS 9	₩ 160,057,000,000
Derivatives liabilities - Financial liabilities at FVTPL (IAS39) - Financial liabilities at FVTPL (IFRS9)
Disclosure of financial liabilities at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Financial liabilities at FVTPL
Classification according to IAS 39	₩ 3,150,149,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Financial liabilities at FVTPL
Classification according to IFRS 9	₩ 3,150,149,000,000
Derivatives liabilities
Disclosure of financial liabilities at date of initial application of IFRS 9 [Line Items]
Classification according to IAS 39	Derivatives liabilities
Classification according to IAS 39	₩ 67,754,000,000
Reclassification	0
Remeasurement	₩ 0
Classification according to IFRS 9	Derivatives liabilities
Classification according to IFRS 9	₩ 67,754,000,000

Basis of preparation and sig107

Basis of preparation and significant accounting policies_Disclosure on financial instruments measured at amortized cost reclassified and financial assets at FVTOCI reclassified from financial assets at FVTPL (Details) - AFS securities ₩ in Millions	6 Months Ended
	Jun. 30, 2018KRW (₩)
Reclassification and mearuement financial assets and financial liabilities at date of initial application of IFRS9 [Line Items]
Fair value	₩ 302,638
Amount of valuation gain / loss had it not been reclassified	₩ (236)

Basis of preparation and sig108

Basis of preparation and significant accounting policies_Evaluation results of credit risk of financial assets at the date of initial recognition (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)
Initial application of impairment requirements for financial instruments [Line Items]
Loss allowance per IAS 39 (A)	₩ 2,079,605,000,000
Increases (B-A)	307,583,000,000
Loss allowance per IFRS 9 (B)	₩ 2,387,188,000,000
Description of initial application of impairment requirements for financial instruments	The impairment model under IFRS 9 reflects expected credit losses, as opposed to incurred credit losses under IFRS 9. Under the impairment approach in IFRS 9, it is no longer necessary for a credit event to have occurred before credit losses are recognized. Instead, the Group accounts for expected credit losses and changes in those expected credit losses. The amount of expected credit losses should be updated at each reporting date to reflect changes in credit risk since initial recognition. The Group is required to recognize the expected credit losses for financial instruments measured at amortized cost or FVTOCI, and loan commitments and financial guarantee contracts that are subject to the impairment provisions of IFRS 9. In particular, when the credit risk of the financial instruments are significantly increased after initial recognition, or when the credit quality of the financial instruments are already impaired at acquisition, the loss allowance is measured as the expected credit loss for the whole life of the financial assets. If the credit risk of a financial instruments does not increase significantly after initial recognition (excluding POCI loans - for financial assets already impaired at initial recognition), the Group measures the loss allowance on the financial instruments at the amount equivalent to the expected 12-month credit loss.
Deposit - Loans and receivables (IAS39) - Loan and other financial assets at amortized cost (IFRS9)
Initial application of impairment requirements for financial instruments [Line Items]
Loss allowance per IAS 39 (A)	₩ 2,458,000,000
Increases (B-A)	634,000,000
Loss allowance per IFRS 9 (B)	3,092,000,000
Debt securities - Available-for-sale financial assets (IAS39) - Financial assets at FVTOCI (IFRS9)
Initial application of impairment requirements for financial instruments [Line Items]
Loss allowance per IAS 39 (A)	0
Increases (B-A)	4,236,000,000
Loss allowance per IFRS 9 (B)	4,236,000,000
Debt securities - Held to maturity financial assets (IAS39) - Securities at amortized cost (IFRS9)
Initial application of impairment requirements for financial instruments [Line Items]
Loss allowance per IAS 39 (A)	0
Increases (B-A)	5,078,000,000
Loss allowance per IFRS 9 (B)	5,078,000,000
Loans and other financial assets - Loans and receivables (IAS39) - Loans and other financial assets at amortized cost (IFRS9)
Initial application of impairment requirements for financial instruments [Line Items]
Loss allowance per IAS 39 (A)	1,827,785,000,000
Increases (B-A)	249,088,000,000
Loss allowance per IFRS 9 (B)	2,076,873,000,000
Payment guarantee
Initial application of impairment requirements for financial instruments [Line Items]
Loss allowance per IAS 39 (A)	183,247,000,000
Increases (B-A)	9,677,000,000
Loss allowance per IFRS 9 (B)	192,924,000,000
Provision for loan commitments
Initial application of impairment requirements for financial instruments [Line Items]
Loss allowance per IAS 39 (A)	66,115,000,000
Increases (B-A)	38,870,000,000
Loss allowance per IFRS 9 (B)	₩ 104,985,000,000

Basis of preparation and sig109

Basis of preparation and significant accounting policies_Information of reclassification and mearuement financial assets and financial liabilities at date of initial application of IFRS 9 (Details) - KRW (₩)	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Disclosure of reclassification and mearuement financial assets and financial liabilities at date of initial application of IFRS9
Information on how entity applied classification requirements in IFRS 9 to financial assets whose classification has changed as result of applying IFRS 9	Debt instruments that are held within a business model whose objective is to collect the contractual cash flows, and that have contractual cash flows that are solely payments of principal and interest on the principal outstanding are generally measured at amortized cost at the end of subsequent accounting periods (financial assets at amortized cost). Debt instruments that are held within a business model whose objective is achieved both by collecting contractual cash flows and selling financial assets, and that have contractual terms that give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding, are generally measured at fair value through other comprehensive income (financial assets at fair value through other comprehensive income (“FVTOCI”)) All other debt instruments and equity instruments are measured at their fair value at the end of subsequent accounting periods (financial assets at fair value through profit or loss (“FVTPL”)).
Description of reasons for designation or de-designation of financial assets or financial liabilities as measured at fair value through profit or loss at date of initial application of IFRS 9	At initial recognition, financial assets at amortized cost or FVTOCI may be irrevocably designated as financial assets at fair value through profit or loss mandatorily measured at fair value if doing so eliminate or significantly reduce a measurement or recognition inconsistency
Debt instruments classified as financial assets at amortized cost		₩ 0
Debt instruments classified as FVOCI		0
Financial assets measured at FVTPL that were reclassified to FVTOCI or amortized cost category		0
Financial liabilities measured at FVTPL that were reclassified to FVTOCI or amortized cost category		0
Financial liabilities As of January 1, 2018		294,813,795,000,000
Financial liabilities designated as at FVTPL As of January 1, 2018		251,796,000,000
Accumulated other comprehensive loss in relation to the changes in credit risk of financial liabilities As of January 1, 2018		₩ (133,000,000)

Basis Of Preparation And Sig110

Basis Of Preparation And Significant Accounting Policies_Impact on accumulated other comprehensive income at date of initial application of IFRS 9 (Details) - KRW (₩) ₩ in Millions		12 Months Ended
		Dec. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2016
Disclosure of effect on other comprehensive income at date of initial application of IFRS9 [Abstract]
Amount recognised in other comprehensive income before application of Ifrs9		₩ (89,723)	₩ (472,038)	₩ 70,750	₩ 173,368
Changes in amount due to reclassification [Abstract]
Reclassification of available-for-sale financial assets to financial assets at Amortized cost		494
Reclassification of available-for-sale financial assets to financial assets at FVTPL		(152,124)
Recognition of expected credit losses of debt securities at FVTOCI		4,293
Reclassified of available for sale financial assets(equity securities) to financial assets at FVTOCI		(397,508)
Effect on changes in credit risk of financial liabilities at fair value through profit or loss designated as upon initial recognition		(133)
Others		3,005
Income tax effect		149,796
Reclassification		(392,177)
Ending balance (based on IFRS9)	[1]	₩ (481,900)
[1]	The beginning balance was restated in accordance with IFRS 9.

Basis of preparation and sig111

Basis of preparation and significant accounting policies_Impact on retained earnings at date of initial application of IFRS 9 (Details) $ in Thousands, ₩ in Millions		12 Months Ended
		Dec. 31, 2017KRW (₩)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)	Dec. 31, 2016KRW (₩)
Disclosure of effect on retained earnings at date of initial application of IFRS9 [Abstract]
Beginning balance (prior to IFRS 9)		₩ 15,620,006	₩ 16,473,453	$ 14,816,921	₩ 15,349,796	₩ 14,611,566
Changes in amount due to reclassification [Abstract]
Reclassification of available-for-sale financial assets to financial assets at Amortized cost		(494)
Reclassification of available-for-sale financial assets to financial assets at FVTPL		152,067
Recognition of expected credit losses of debt instruments at FVTOCI		(4,236)
Reclassified of available for sale financial assets(equity securities) to financial assets at FVTOCI		397,508
Effect on revaluation of financial assets at amortized cost from loan and receivables or AFS financial assets		282
Recognition of expected credit losses of financial assets at amortized cost which were previously loan and receivables		(240,683)
Effect of payment guarantees / unused commitments on liabilities		(48,548)
Effect on changes in credit risk of financial liabilities at fair value through profit or loss designated as upon initial recognition		133
Others		(4,456)
Income tax effect		(74,482)
Reclassification		177,091
Ending balance (based on IFRS9)	[1]	₩ 15,797,097
[1]	The beginning balance was restated in accordance with IFRS 9.

Basis of preparation and sig112

Basis of preparation and significant accounting policies_IFRS the Group not applied has been issued but is not yet effective (Details) - Enactment of IFRS 16 Leases	6 Months Ended
	Jun. 30, 2018
Description of expected impact of initial application of new standards or interpretations [Line Items]
Title of new IFRS	Leases
Explanation of not applied new standards or interpretations	IFRS 16 will supersede the current lease guidance including IAS 17 Leases and the related interpretations, and will be applied to periods beginning on or after January 1, 2019.
Description of nature of impending change in accounting policy	IFRS 16 distinguishes leases and service contracts on the basis of whether an identified asset is controlled by a customer. Distinctions of operating leases and finance leases are removed for lessee accounting, and is replaced by model where a right-of-use asset and corresponding liability have to be recognized for all leases by lessees except for short-term leases and leases of low value assets. The right-of-use asset is initially measured at cost and subsequently measured at cost (subject to certain exceptions) less accumulated depreciation and impairment losses, adjusted for any remeasurement of the lease liability. The lease liability is initially measured at the present value of the lease payments that are not paid at that date. Subsequently, the lease liability is adjusted for interest and lease payments, as well as the impact of lease modifications, amongst others. Furthermore, the classification of cash flows will also be affected as operating lease payments under IAS 17 are presented as operating cash flows; whereas under the IFRS 16 model, the lease payments will be split into a principal and an interest portion which will be presented as financing and operating cash flows respectively. In contrast to lessee accounting, IFRS 16 substantially carries forward the lessor accounting requirements in IAS 17, and continues to require a lessor to classify a lease either as an operating lease or a finance lease. Also, IFRS 16 requires expanded disclosures
Date by which application of new IFRS is required	Jan. 1, 2019
Date as at which entity plans to apply new IFRS initially	Jan. 1, 2019
Discussion of impact that initial application of IFRS is expected to have on financial statements	According to the preliminary assessment of the Group, the lease agreements entered into by the Group as of June 30, 2018 are expected to meet the definition of lease under the Standard, and accordingly, if the Group adopts the Standard, it applies to all leases except short-term leases and leases of low value assets, and the Group will recognize the right-of-use assets and related liabilities accordingly.
Description of fact that impact of initial application of new IFRS is not known or reasonably estimable	The Group is currently analyzing the potential impact of this standards as of June 30, 2018.

Significant accounting estim113

Significant accounting estimates and assumptions _Estimates and assumptions (Details)	6 Months Ended
	Jun. 30, 2018
Disclosure of changes in accounting estimates [Line Items]
Explanation of nature and amount of changes in estimates of amounts reported in prior interim periods or prior financial years	The significant judgments which management has made about the application of the Group’s accounting policies and key sources of uncertainty in estimate do not differ from those used in preparing the consolidated financial statements for the year ended December 31, 2017, except the Group’s policy, accounting estimates and assumptions described below;
Income taxes
Disclosure of changes in accounting estimates [Line Items]
Description of nature and amount of change in accounting estimate	If certain portion of the taxable income is not used for investments, increase in wages, and others in accordance with the Tax System for Promotion of investment and Collaborative Cooperation (Recirculation of Corporate Income), the Group is liable to pay additional income tax calculated based on the tax laws. The new tax system is effective for three years from 2018. Accordingly, the measurement of current and deferred income tax is affected by the tax effects from the new system.
Description of fact that amount of change in accounting estimateIs impracticable	As the Group’s income tax is dependent on the investments, increase in wages, and others, there exists uncertainty with regard to measuring the final tax effects.
Provisions for credit losses (allowances for loan losses, provisions for acceptances and guarantees, and unused loan commitments)
Disclosure of changes in accounting estimates [Line Items]
Description of nature and amount of change in accounting estimate	In accordance with IFRS 9, the Group tests impairment and recognizes allowances for losses on financial assets classified at amortized cost, and debt instruments measured at fair value through other comprehensive income and lease receivables through impairment testing and recognizes provisions for guarantees, and unused loan commitments.
Description of fact that amount of change in accounting estimateIs impracticable	Accuracy of provisions for credit losses is dependent upon estimation of expected cash flows of the borrower for individually assessed allowances of loans, and upon assumptions and methodology used for collectively assessed allowances for the Group’s of loans, guarantees and unused loan commitments.

Risk management_Maximum exposur

Risk management_Maximum exposure to credit risk (Details)	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Disclosure of credit risk exposure [Line Items]
Total	₩ 424,543,885,000,000			₩ 396,559,830,000,000
Categories of financial assets
Loans and other financial assets at amortized cost	277,720,003,000,000	[1]	$ 249,793,131,000	0
Securities at amortized cost	17,702,129,000,000	[1]	15,922,044,000	0
Loans and receivables	0		0	267,106,204,000,000
Financial assets at FVTPL (IAS 39)	0			5,795,774,000,000
Financial assets at FVTPL (IFRS 9)	4,746,950,000,000			0
AFS debt securities				13,229,244,000,000
Financial assets at FVTOCI	13,738,829,000,000	[2]		0
HTM securities	0		0	16,749,296,000,000
Derivative assets for hedging	12,395,000,000		$ 11,149,000	59,272,000,000
Off balance sheet item
Off balance sheet items	110,623,579,000,000			93,620,040,000,000
Korean treasury and government agencies
Categories of financial assets
Loans and other financial assets at amortized cost	17,912,135,000,000			0
Banks
Categories of financial assets
Loans and other financial assets at amortized cost	21,942,788,000,000			0
Corporates
Categories of financial assets
Loans and other financial assets at amortized cost	92,333,155,000,000			0
Consumers
Categories of financial assets
Loans and other financial assets at amortized cost	145,531,925,000,000			0
Korean treasury and government agencies
Categories of financial assets
Loans and other financial assets at amortized cost	17,912,135,000,000
Loans and receivables	0			8,823,584,000,000
Banks
Categories of financial assets
Loans and other financial assets at amortized cost	21,942,788,000,000
Loans and receivables	0			26,845,309,000,000
Corporates
Categories of financial assets
Loans and other financial assets at amortized cost	92,333,155,000,000
Loans and receivables	0			90,570,551,000,000
Consumers
Categories of financial assets
Loans and other financial assets at amortized cost	145,531,925,000,000
Loans and receivables	0			140,866,760,000,000
Deposits
Categories of financial assets
Financial assets at FVTPL (IFRS 9)	24,921,000,000			0
Debt securities
Categories of financial assets
Financial assets at FVTPL (IFRS 9)	1,993,851,000,000			0
Loans
Categories of financial assets
Financial assets at FVTPL (IFRS 9)	336,967,000,000			0
Derivative assets
Categories of financial assets
Financial assets at FVTPL (IFRS 9)	2,391,211,000,000			0
Deposits
Categories of financial assets
Financial assets at FVTPL (IAS 39)	0			25,972,000,000
Debt securities
Categories of financial assets
Financial assets at FVTPL (IAS 39)	0			2,644,333,000,000
Financial assets designated at FVTPL
Categories of financial assets
Financial assets at FVTPL (IAS 39)	0			9,694,000,000
Derivative assets
Categories of financial assets
Financial assets at FVTPL (IAS 39)	0			3,115,775,000,000
Financial assets at FVTOCI debt securities
Categories of financial assets
Financial assets at FVTOCI	13,738,829,000,000			0
Available for sale debt securities
Categories of financial assets
AFS debt securities	0			13,229,244,000,000
Debt securities at amortized cost
Categories of financial assets
Securities at amortized cost				0
Held to maturity debt securities
Categories of financial assets
HTM securities	0			16,749,296,000,000
Derivative assets for hedging
Categories of financial assets
Derivative assets for hedging	12,395,000,000			59,272,000,000
Guarantees
Off balance sheet item
Off balance sheet items	12,372,573,000,000			12,859,715,000,000
Loan commitments
Off balance sheet item
Off balance sheet items	₩ 98,251,006,000,000			₩ 80,760,325,000,000
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.
[2]	Financial assets at FVTOCI have not been disclosed as the amount before deducting provisions because the carrying amount does not decrease.

Risk management_Credit risk exp

Risk management_Credit risk exposure by geographical areas (Details)		Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Categories of financial assets
Loans and other financial assets at amortized cost		₩ 277,720,003,000,000	[1]	$ 249,793,131,000	₩ 0
Securities at amortized cost		17,702,129,000,000	[1]	15,922,044,000	0
Loans and receivables		0		0	267,106,204,000,000
Financial assets at FVTPL (IAS 39)		0			5,795,774,000,000
Financial assets at FVTPL (IFRS 9)		4,746,950,000,000			0
AFS debt securities					13,229,244,000,000
Financial assets at FVTOCI		13,738,829,000,000	[2]		0
HTM securities		0		0	16,749,296,000,000
Derivative assets for hedging		12,395,000,000		$ 11,149,000	59,272,000,000
Off balance sheet item
Off balance sheet items		110,623,579,000,000			93,620,040,000,000
Total		424,543,885,000,000			396,559,830,000,000
Korea
Categories of financial assets
Loans and other financial assets at amortized cost		258,023,468,000,000
Securities at amortized cost		17,531,402,000,000
Loans and receivables					250,678,479,000,000
Financial assets at FVTPL (IAS 39)					5,551,870,000,000
Financial assets at FVTPL (IFRS 9)		4,493,256,000,000
AFS debt securities					12,407,602,000,000
Financial assets at FVTOCI		12,749,695,000,000
HTM securities					16,606,692,000,000
Derivative assets for hedging		7,450,000,000			16,590,000,000
Off balance sheet item
Off balance sheet items		108,052,029,000,000			91,603,852,000,000
Total		400,857,300,000,000			376,865,085,000,000
China
Categories of financial assets
Loans and other financial assets at amortized cost		4,589,930,000,000
Securities at amortized cost		0
Loans and receivables					4,104,912,000,000
Financial assets at FVTPL (IAS 39)					2,937,000,000
Financial assets at FVTPL (IFRS 9)		6,077,000,000
AFS debt securities					52,259,000,000
Financial assets at FVTOCI		50,874,000,000
HTM securities					0
Derivative assets for hedging		0			0
Off balance sheet item
Off balance sheet items		928,841,000,000			529,193,000,000
Total		5,575,722,000,000			4,689,301,000,000
USA
Categories of financial assets
Loans and other financial assets at amortized cost		4,514,541,000,000
Securities at amortized cost		64,856,000,000
Loans and receivables					2,823,247,000,000
Financial assets at FVTPL (IAS 39)					0
Financial assets at FVTPL (IFRS 9)		0
AFS debt securities					151,131,000,000
Financial assets at FVTOCI		43,352,000,000
HTM securities					63,732,000,000
Derivative assets for hedging		0			0
Off balance sheet item
Off balance sheet items		175,050,000,000			172,570,000,000
Total		4,797,799,000,000			3,210,680,000,000
UK
Categories of financial assets
Loans and other financial assets at amortized cost		1,268,461,000,000
Securities at amortized cost		0
Loans and receivables					1,094,988,000,000
Financial assets at FVTPL (IAS 39)					148,955,000,000
Financial assets at FVTPL (IFRS 9)		147,242,000,000
AFS debt securities					0
Financial assets at FVTOCI		78,485,000,000
HTM securities					0
Derivative assets for hedging		4,945,000,000			42,682,000,000
Off balance sheet item
Off balance sheet items		70,503,000,000			66,974,000,000
Total		1,569,636,000,000			1,353,599,000,000
Japan
Categories of financial assets
Loans and other financial assets at amortized cost		400,907,000,000
Securities at amortized cost		0
Loans and receivables					381,890,000,000
Financial assets at FVTPL (IAS 39)					0
Financial assets at FVTPL (IFRS 9)		0
AFS debt securities					0
Financial assets at FVTOCI		2,274,000,000
HTM securities					0
Derivative assets for hedging		0			0
Off balance sheet item
Off balance sheet items		31,216,000,000			25,039,000,000
Total		434,397,000,000			406,929,000,000
Others
Categories of financial assets
Loans and other financial assets at amortized cost	[3]	8,922,696,000,000
Securities at amortized cost	[3]	105,871,000,000
Loans and receivables	[3]				8,022,688,000,000
Financial assets at FVTPL (IAS 39)	[3]				92,012,000,000
Financial assets at FVTPL (IFRS 9)	[3]	100,375,000,000
AFS debt securities	[3]				618,252,000,000
Financial assets at FVTOCI	[3]	814,149,000,000
HTM securities	[3]				78,872,000,000
Derivative assets for hedging		0			0
Off balance sheet item
Off balance sheet items	[3]	1,365,940,000,000			1,222,412,000,000
Total	[3]	₩ 11,309,031,000,000			₩ 10,034,236,000,000
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.
[2]	Financial assets at FVTOCI have not been disclosed as the amount before deducting provisions because the carrying amount does not decrease.
[3]	Others consist of financial assets in Indonesia, Hong Kong, Singapore, and other countries.

Risk management_Credit risk 116

Risk management_Credit risk exposure by industries (Details)	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Disclosure of credit risk exposure [Line Items]
Total	₩ 424,543,885,000,000			₩ 396,559,830,000,000
Categories of financial assets
Loans and other financial assets at amortized cost	277,720,003,000,000	[1]	$ 249,793,131,000	0
Securities at amortized cost	17,702,129,000,000	[1]	15,922,044,000	0
Loans and receivables	0		0	267,106,204,000,000
Financial assets at FVTPL (IAS 39)	0			5,795,774,000,000
Financial assets at FVTPL (IFRS 9)	4,746,950,000,000			0
AFS debt securities				13,229,244,000,000
Financial assets at FVTOCI	13,738,829,000,000	[2]		0
HTM securities	0		0	16,749,296,000,000
Derivative assets for hedging	12,395,000,000		$ 11,149,000	59,272,000,000
Off balance sheet item
Off balance sheet items	110,623,579,000,000			93,620,040,000,000
Service
Disclosure of credit risk exposure [Line Items]
Total	67,936,875,000,000			66,242,824,000,000
Categories of financial assets
Loans and other financial assets at amortized cost	48,025,922,000,000
Securities at amortized cost	1,142,178,000,000
Loans and receivables				47,192,641,000,000
Financial assets at FVTPL (IAS 39)				100,766,000,000
Financial assets at FVTPL (IFRS 9)	97,529,000,000
AFS debt securities				707,737,000,000
Financial assets at FVTOCI	434,389,000,000
HTM securities				1,348,754,000,000
Derivative assets for hedging	0
Off balance sheet item
Off balance sheet items	18,236,857,000,000			16,892,926,000,000
Manufacturing
Disclosure of credit risk exposure [Line Items]
Total	58,479,235,000,000			56,050,845,000,000
Categories of financial assets
Loans and other financial assets at amortized cost	35,583,702,000,000
Securities at amortized cost	0
Loans and receivables				34,502,509,000,000
Financial assets at FVTPL (IAS 39)				83,239,000,000
Financial assets at FVTPL (IFRS 9)	166,054,000,000
AFS debt securities				37,719,000,000
Financial assets at FVTOCI	54,445,000,000
HTM securities				0
Derivative assets for hedging	0
Off balance sheet item
Off balance sheet items	22,675,034,000,000			21,427,378,000,000
Finance and insurance
Disclosure of credit risk exposure [Line Items]
Total	75,664,321,000,000			71,094,693,000,000
Categories of financial assets
Loans and other financial assets at amortized cost	42,207,115,000,000
Securities at amortized cost	11,516,407,000,000
Loans and receivables				38,260,051,000,000
Financial assets at FVTPL (IAS 39)				4,640,068,000,000
Financial assets at FVTPL (IFRS 9)	3,404,674,000,000
AFS debt securities				7,331,774,000,000
Financial assets at FVTOCI	9,020,012,000,000
HTM securities				10,962,149,000,000
Derivative assets for hedging	12,395,000,000			59,272,000,000
Off balance sheet item
Off balance sheet items	9,503,718,000,000			9,841,379,000,000
Construction
Disclosure of credit risk exposure [Line Items]
Total	8,282,361,000,000			7,882,046,000,000
Categories of financial assets
Loans and other financial assets at amortized cost	3,657,220,000,000
Securities at amortized cost	313,936,000,000
Loans and receivables				3,574,746,000,000
Financial assets at FVTPL (IAS 39)				15,073,000,000
Financial assets at FVTPL (IFRS 9)	43,899,000,000
AFS debt securities				153,534,000,000
Financial assets at FVTOCI	214,549,000,000
HTM securities				296,214,000,000
Derivative assets for hedging	0
Off balance sheet item
Off balance sheet items	4,052,757,000,000			3,842,479,000,000
Individuals
Disclosure of credit risk exposure [Line Items]
Total	188,014,893,000,000			170,023,881,000,000
Categories of financial assets
Loans and other financial assets at amortized cost	138,906,711,000,000
Securities at amortized cost	0
Loans and receivables				133,094,287,000,000
Financial assets at FVTPL (IAS 39)				1,040,000,000
Financial assets at FVTPL (IFRS 9)	3,019,000,000
AFS debt securities				0
Financial assets at FVTOCI	0
HTM securities				0
Derivative assets for hedging	0
Off balance sheet item
Off balance sheet items	49,105,163,000,000			36,928,554,000,000
Others
Disclosure of credit risk exposure [Line Items]
Total	26,166,200,000,000			25,265,541,000,000
Categories of financial assets
Loans and other financial assets at amortized cost	9,339,333,000,000
Securities at amortized cost	4,729,608,000,000
Loans and receivables				10,481,970,000,000
Financial assets at FVTPL (IAS 39)				955,588,000,000
Financial assets at FVTPL (IFRS 9)	1,031,775,000,000
AFS debt securities				4,998,480,000,000
Financial assets at FVTOCI	4,015,434,000,000
HTM securities				4,142,179,000,000
Derivative assets for hedging	0
Off balance sheet item
Off balance sheet items	₩ 7,050,050,000,000			₩ 4,687,324,000,000
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.
[2]	Financial assets at FVTOCI have not been disclosed as the amount before deducting provisions because the carrying amount does not decrease.

Risk management_Description of

Risk management_Description of the Group's credit risk exposure (Details)	6 Months Ended
	Jun. 30, 2018
Disclosure of nature and extent of risks arising from financial instruments [Line Items]
Description of how forward-looking information has been incorporated into determination of expected credit losses	The Group has estimated the allowance for credit losses based on experience losses with taken account of forward-looking information. The probability of default and loss at given default per financial assets considering account type of borrowers, credit rate grade, portfolio are used in estimation of allowance for expected credit losses and those factors are reviewed periodically to reduce the difference of expected losses and actual losses. The Group also measures expected credit losses using supportive and reasonable macroeconomic indicators, such as economic growth rates, interest rates, and composite stock indices. The methods for the estimation of forward-looking are also regularly reviewed. The Group undertakes the following procedures in order to predict and apply the forward-looking economic information: - Development of a prediction model by analyzing the correlation between macroeconomic data and yearly default rate of corporate and retail exposures. - Calculation of predicted annual default rate by applying forward-looking economic information, which includes estimated macroeconomic indices provided by verified institutions such as Bank of Korea and National Assembly Budget Office, to the prediction model developed. - If the predicted default rate is above the applicable default rate of the current period, application of the increase in default rate as a form of adjustment coefficient to the forward-looking economic information, thereby adjusting the current period estimation.
Information on how entity determined whether credit risk of financial instruments has increased significantly since initial recognition	At the end of each period the Group evaluates whether there has been a significant increase in the credit risk since initial recognition. The Group is assessing the change in the risk of a default occurring over the expected life of the financial instruments instead of the change in the amount of expected credit losses.
Information on how instruments were grouped if expected credit losses were measured on collective basis	The Group distinguishes corporates/consumers exposures when determining significant increase in credit risk
Information on how entity determined that financial assets are credit-impaired financial assets	The financial assets are impaired if the following conditions are met; - The principal and interest of the loan has been overdue for more than 90 days due to the serious deterioration of the credit condition, - It is deemed that the borrowers will not pay any portion of the debts without actions of recourse such as the disposition of the collateral is not taken - Objective evidence of impairment of financial assets are identified
Information on entity's write-off policy	The Group writes off assets when it is determined that the receivables are virtually impossible to collect. The Group determines which receivable to write-off and subsequently writes them off in accordance with the company’s policy. Regardless of whether assets have been written off, the Group may continue to exercise its right of collection in accordance with company’s policy on receivables collection.
Stage 1
Disclosure of nature and extent of risks arising from financial instruments [Line Items]
Description of basis of inputs and assumptions and estimation techniques used to measure 12-month and lifetime expected credit losses	Expected credit losses due to possible defaults on financial instruments within a 12-month period from the reporting date. Credit risk may be considered to not have been significantly increased when credit risk is low at the reporting date.	[1]
Stage 2
Disclosure of nature and extent of risks arising from financial instruments [Line Items]
Description of basis of inputs and assumptions and estimation techniques used to determine whether credit risk of financial instruments have increased significantly since initial recognition	Expected credit losses from all possible defaults during the expected lifetime of the financial instruments.
Stage 3
Disclosure of nature and extent of risks arising from financial instruments [Line Items]
Description of basis of inputs and assumptions and estimation techniques used to determine whether financial asset is credit-impaired financial asset	Expected credit losses from all possible defaults during the expected lifetime of the financial instruments. The financial assets are impaired if the following conditions are met; - The principal and interest of the loan has been overdue for more than 90 days due to the serious deterioration of the credit condition, - It is deemed that the borrowers will not pay any portion of the debts without actions of recourse such as the disposition of the collateral is not taken - Objective evidence of impairment of financial assets are identified
[1]	Credit risk may be considered to not have been significantly increased when credit risk is low at the reporting date.

Risk management_Maximum expo118

Risk management_Maximum exposure to credit risk of financia assets except for financial assets at FVTPL and derivative assets by three stages (Details) $ in Thousands		Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		₩ 277,720,003,000,000	[1]	$ 249,793,131	₩ 0
Securities at amortized cost		17,702,129,000,000	[1]	$ 15,922,044	0
Financial assets at FVTOCI		13,738,829,000,000	[2]		0
Total		309,160,961,000,000
Collateral value of damaged property		789,660,000,000
Stage 1 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total	[3]	278,102,772,000,000
Stage 1 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total	[4]	18,842,655,000,000
Lifetime expected credit losses [Member] | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total		310,996,966,000,000
Lifetime expected credit losses [Member] | Loss allowance
Disclosure of credit risk exposure [Line Items]
Total		(1,840,675,000,000)
Stage 2 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total	[3]	6,210,506,000,000
Stage 2 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total	[4]	5,772,369,000,000
Stage 3 | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total		2,068,664,000,000
Loans and other financial assets at amortized cost
Disclosure of credit risk exposure [Line Items]
Collateral value of damaged property		789,660,000,000
Loans and other financial assets at amortized cost | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		279,550,758,000,000
Loans and other financial assets at amortized cost | Loss allowance
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		(1,830,755,000,000)
Loans and other financial assets at amortized cost | Stage 1 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	246,719,865,000,000
Loans and other financial assets at amortized cost | Stage 1 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	18,794,529,000,000
Loans and other financial assets at amortized cost | Stage 2 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	6,195,331,000,000
Loans and other financial assets at amortized cost | Stage 2 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	5,772,369,000,000
Loans and other financial assets at amortized cost | Stage 3 | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		2,068,664,000,000
Korean treasury and government agencies
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		17,912,135,000,000
Collateral value of damaged property		0
Korean treasury and government agencies | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		17,916,231,000,000
Korean treasury and government agencies | Loss allowance
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		(4,096,000,000)
Korean treasury and government agencies | Stage 1 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	17,916,231,000,000
Korean treasury and government agencies | Stage 1 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		0
Korean treasury and government agencies | Stage 2 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		0
Korean treasury and government agencies | Stage 2 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		0
Korean treasury and government agencies | Stage 3 | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		0
Banks
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		21,942,788,000,000
Collateral value of damaged property		0
Banks | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		21,963,678,000,000
Banks | Loss allowance
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		(20,890,000,000)
Banks | Stage 1 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	21,599,560,000,000
Banks | Stage 1 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	83,471,000,000
Banks | Stage 2 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	269,742,000,000
Banks | Stage 2 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		0
Banks | Stage 3 | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		10,905,000,000
Corporates
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		92,333,155,000,000
Collateral value of damaged property		555,228,000,000
Corporates | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		93,543,175,000,000
Corporates | Loss allowance
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		(1,210,020,000,000)
Corporates | Stage 1 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	72,113,414,000,000
Corporates | Stage 1 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	15,745,380,000,000
Corporates | Stage 2 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	582,857,000,000
Corporates | Stage 2 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	3,618,576,000,000
Corporates | Stage 3 | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		1,482,948,000,000
General business
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		51,875,159,000,000
Collateral value of damaged property		405,304,000,000
General business | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		52,718,524,000,000
General business | Loss allowance
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		(843,365,000,000)
General business | Stage 1 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	42,620,870,000,000
General business | Stage 1 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	6,674,237,000,000
General business | Stage 2 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	510,663,000,000
General business | Stage 2 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	1,681,120,000,000
General business | Stage 3 | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		1,231,634,000,000
Small and medium sized enterprise
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		35,237,952,000,000
Collateral value of damaged property		130,181,000,000
Small and medium sized enterprise | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		35,565,275,000,000
Small and medium sized enterprise | Loss allowance
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		(327,323,000,000)
Small and medium sized enterprise | Stage 1 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	25,012,286,000,000
Small and medium sized enterprise | Stage 1 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	8,491,759,000,000
Small and medium sized enterprise | Stage 2 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	72,194,000,000
Small and medium sized enterprise | Stage 2 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	1,766,232,000,000
Small and medium sized enterprise | Stage 3 | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		222,804,000,000
Project financing and others
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		5,220,044,000,000
Collateral value of damaged property		19,743,000,000
Project financing and others | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		5,259,376,000,000
Project financing and others | Loss allowance
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		(39,332,000,000)
Project financing and others | Stage 1 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	4,480,258,000,000
Project financing and others | Stage 1 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	579,384,000,000
Project financing and others | Stage 2 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		0
Project financing and others | Stage 2 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	171,224,000,000
Project financing and others | Stage 3 | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		28,510,000,000
Consumers
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		145,531,925,000,000
Collateral value of damaged property		234,432,000,000
Consumers | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		146,127,674,000,000
Consumers | Loss allowance
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		(595,749,000,000)
Consumers | Stage 1 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	135,090,660,000,000
Consumers | Stage 1 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	2,965,678,000,000
Consumers | Stage 2 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[3]	5,342,732,000,000
Consumers | Stage 2 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost	[4]	2,153,793,000,000
Consumers | Stage 3 | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Loans and other financial assets at amortized cost		574,811,000,000
Securities at amortized cost
Disclosure of credit risk exposure [Line Items]
Securities at amortized cost					₩ 0
Collateral value of damaged property		0
Securities at amortized cost | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Securities at amortized cost		17,707,379,000,000
Securities at amortized cost | Loss allowance
Disclosure of credit risk exposure [Line Items]
Securities at amortized cost		(5,250,000,000)
Securities at amortized cost | Stage 1 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Securities at amortized cost	[3]	17,707,379,000,000
Securities at amortized cost | Stage 1 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Securities at amortized cost		0
Securities at amortized cost | Stage 2 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Securities at amortized cost		0
Securities at amortized cost | Stage 2 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Securities at amortized cost		0
Securities at amortized cost | Stage 3 | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Securities at amortized cost		0
Financial assets at FVTOCI | Stage 1 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Financial assets at FVTOCI	[3]	13,675,528,000,000
Financial assets at FVTOCI | Stage 1 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Financial assets at FVTOCI	[4]	48,126,000,000
Financial assets at FVTOCI | Lifetime expected credit losses [Member]
Disclosure of credit risk exposure [Line Items]
Collateral value of damaged property		0
Financial assets at FVTOCI | Lifetime expected credit losses [Member] | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Financial assets at FVTOCI	[2]	13,738,829,000,000
Financial assets at FVTOCI | Lifetime expected credit losses [Member] | Loss allowance
Disclosure of credit risk exposure [Line Items]
Financial assets at FVTOCI	[2]	(4,670,000,000)
Financial assets at FVTOCI | Stage 2 | Above appropriate credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Financial assets at FVTOCI	[3]	15,175,000,000
Financial assets at FVTOCI | Stage 2 | Less than a limited credit rating | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Financial assets at FVTOCI		0
Financial assets at FVTOCI | Stage 3 | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Financial assets at FVTOCI		₩ 0
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.
[2]	Financial assets at FVTOCI have not been disclosed as the amount before deducting provisions because the carrying amount does not decrease.
[3]	Credit grade of corporates are AAA ~ BBB, and consumers are grades 1 ~ 6.
[4]	Credit grade of corporates are BBB- ~ C, and consumers are grades 7 ~ 10.

Risk management_Maximum expo119

Risk management_Maximum exposure to credit risk of loans and receivables in accordance with IAS 39 by customers (Details)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Disclosure of credit risk exposure [Line Items]
Total net	₩ 0	$ 0	₩ 267,106,204,000,000
Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			268,936,446,000,000
Loss allowance
Disclosure of credit risk exposure [Line Items]
Total net			1,830,242,000,000
Loans and receivables neither overdue nor impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			265,692,069,000,000
Loans and receivables overdue but not impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			1,007,097,000,000
Impaired loans and receivables | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			2,237,280,000,000
Korean treasury and government agencies
Disclosure of credit risk exposure [Line Items]
Total net	0		8,823,584,000,000
Korean treasury and government agencies | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			8,825,775,000,000
Korean treasury and government agencies | Loss allowance
Disclosure of credit risk exposure [Line Items]
Total net			2,191,000,000
Korean treasury and government agencies | Loans and receivables neither overdue nor impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			8,825,767,000,000
Korean treasury and government agencies | Loans and receivables overdue but not impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			8,000,000
Korean treasury and government agencies | Impaired loans and receivables | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			0
Banks
Disclosure of credit risk exposure [Line Items]
Total net	0		26,845,309,000,000
Banks | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			26,861,286,000,000
Banks | Loss allowance
Disclosure of credit risk exposure [Line Items]
Total net			15,977,000,000
Banks | Loans and receivables neither overdue nor impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			26,861,286,000,000
Banks | Loans and receivables overdue but not impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			0
Banks | Impaired loans and receivables | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			0
Corporates
Disclosure of credit risk exposure [Line Items]
Total net	0		90,570,551,000,000
Corporates | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			91,947,571,000,000
Corporates | Loss allowance
Disclosure of credit risk exposure [Line Items]
Total net			1,377,020,000,000
Corporates | Loans and receivables neither overdue nor impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			90,118,609,000,000
Corporates | Loans and receivables overdue but not impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			128,683,000,000
Corporates | Impaired loans and receivables | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			1,700,279,000,000
General business
Disclosure of credit risk exposure [Line Items]
Total net			50,852,126,000,000
General business | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			51,930,859,000,000
General business | Loss allowance
Disclosure of credit risk exposure [Line Items]
Total net			1,078,733,000,000
General business | Loans and receivables neither overdue nor impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			50,463,112,000,000
General business | Loans and receivables overdue but not impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			65,616,000,000
General business | Impaired loans and receivables | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			1,402,131,000,000
Small and medium sized enterprise
Disclosure of credit risk exposure [Line Items]
Total net			34,154,883,000,000
Small and medium sized enterprise | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			34,422,045,000,000
Small and medium sized enterprise | Loss allowance
Disclosure of credit risk exposure [Line Items]
Total net			267,162,000,000
Small and medium sized enterprise | Loans and receivables neither overdue nor impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			34,107,547,000,000
Small and medium sized enterprise | Loans and receivables overdue but not impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			63,067,000,000
Small and medium sized enterprise | Impaired loans and receivables | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			251,431,000,000
Project financing and others
Disclosure of credit risk exposure [Line Items]
Total net			5,563,542,000,000
Project financing and others | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			5,594,667,000,000
Project financing and others | Loss allowance
Disclosure of credit risk exposure [Line Items]
Total net			31,125,000,000
Project financing and others | Loans and receivables neither overdue nor impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			5,547,950,000,000
Project financing and others | Loans and receivables overdue but not impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			0
Project financing and others | Impaired loans and receivables | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			46,717,000,000
Consumers
Disclosure of credit risk exposure [Line Items]
Total net	₩ 0		140,866,760,000,000
Consumers | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			141,301,814,000,000
Consumers | Loss allowance
Disclosure of credit risk exposure [Line Items]
Total net			435,054,000,000
Consumers | Loans and receivables neither overdue nor impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			139,886,407,000,000
Consumers | Loans and receivables overdue but not impaired | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			878,406,000,000
Consumers | Impaired loans and receivables | Gross loans and receivables
Disclosure of credit risk exposure [Line Items]
Total net			₩ 537,001,000,000

Risk management_Details of loan

Risk management_Details of loans and receivables pastdue and impaired net of allowance (Details) ₩ in Millions	12 Months Ended
	Dec. 31, 2017KRW (₩)
Disclosure of credit risk exposure [Line Items]
Financial assets at FVTPL	₩ 2,654,027	[1]
AFS debt securities	13,229,244
HTM securities	16,749,296
Total	₩ 32,632,567
Description of rating agencies used	External Credit Assessment Institution (“ECAI”), Korea’s qualified external rating agency
AAA
Disclosure of credit risk exposure [Line Items]
Financial assets at FVTPL	₩ 1,685,099	[1]
AFS debt securities	9,897,689
HTM securities	15,806,327
Total	27,389,115
From AA minus to AA plus
Disclosure of credit risk exposure [Line Items]
Financial assets at FVTPL	722,923	[1]
AFS debt securities	2,386,567
HTM securities	888,547
Total	3,998,037
From BBB minus to A plus
Disclosure of credit risk exposure [Line Items]
Financial assets at FVTPL	236,311	[1]
AFS debt securities	876,482
HTM securities	52,188
Total	1,164,981
Below BBB minus
Disclosure of credit risk exposure [Line Items]
Financial assets at FVTPL	9,694	[1]
AFS debt securities	68,506
HTM securities	2,234
Total	₩ 80,434
[1]	Financial assets at FVTPL comprise debt securities held for trading and financial assets designated at FVTPL

Risk management_Credit soundnes

Risk management_Credit soundness of debt securities (Details) - KRW (₩) ₩ in Millions		Jun. 30, 2018	Dec. 31, 2017
Disclosure of credit risk exposure [Line Items]
Off balance accounts		₩ 110,623,579	₩ 93,620,040
Guarantees
Disclosure of credit risk exposure [Line Items]
Off balance accounts		12,372,573	12,859,715
Loan commitments
Disclosure of credit risk exposure [Line Items]
Off balance accounts		98,251,006	₩ 80,760,325
Stage 1 | Above appropriate credit rating | Off balance sheet items
Disclosure of credit risk exposure [Line Items]
Off balance accounts	[1]	103,019,261
Stage 1 | Above appropriate credit rating | Guarantees
Disclosure of credit risk exposure [Line Items]
Off balance accounts	[1]	10,684,154
Stage 1 | Above appropriate credit rating | Loan commitments
Disclosure of credit risk exposure [Line Items]
Off balance accounts	[1]	92,335,107
Stage 1 | Less than a limited credit rating | Off balance sheet items
Disclosure of credit risk exposure [Line Items]
Off balance accounts	[2]	4,821,887
Stage 1 | Less than a limited credit rating | Guarantees
Disclosure of credit risk exposure [Line Items]
Off balance accounts	[2]	1,104,097
Stage 1 | Less than a limited credit rating | Loan commitments
Disclosure of credit risk exposure [Line Items]
Off balance accounts	[2]	3,717,790
Stage 2 | Above appropriate credit rating | Off balance sheet items
Disclosure of credit risk exposure [Line Items]
Off balance accounts	[1]	1,468,348
Stage 2 | Above appropriate credit rating | Guarantees
Disclosure of credit risk exposure [Line Items]
Off balance accounts	[1]	12,464
Stage 2 | Above appropriate credit rating | Loan commitments
Disclosure of credit risk exposure [Line Items]
Off balance accounts	[1]	1,455,884
Stage 2 | Less than a limited credit rating | Off balance sheet items
Disclosure of credit risk exposure [Line Items]
Off balance accounts	[2]	1,130,536
Stage 2 | Less than a limited credit rating | Guarantees
Disclosure of credit risk exposure [Line Items]
Off balance accounts	[2]	390,253
Stage 2 | Less than a limited credit rating | Loan commitments
Disclosure of credit risk exposure [Line Items]
Off balance accounts	[2]	740,283
Stage 3 | Off balance sheet items
Disclosure of credit risk exposure [Line Items]
Off balance accounts		183,547
Stage 3 | Guarantees
Disclosure of credit risk exposure [Line Items]
Off balance accounts		181,605
Stage 3 | Loan commitments
Disclosure of credit risk exposure [Line Items]
Off balance accounts		₩ 1,942
[1]	Credit grade of corporates are AAA ~ BBB, and consumers are grades 1 ~ 6.
[2]	Credit grade of corporates are BBB- ~ C, and consumers are grades 7 ~ 10.

Risk management_Collateral and

Risk management_Collateral and other credit enhancements (Details)	6 Months Ended
	Jun. 30, 2018
Disclosure of collateral held as security and other credit enhancements [Abstract]
Description of collateral held as security and other credit enhancements and their financial effect in respect of amount that best represents maximum exposure	There have been no significant changes in the value of collateral or other credit enhancements held by the Group during the current quarter, changes in collateral or other credit enhancements due to changes in the collateral policy of the Group. As of June 30, 2018, there are no financial assets that do not recognize the allowance for losses due to collateral.

Risk Management_Sensitivity Ana

Risk Management_Sensitivity Analysis of Market Risk (Details)	6 Months Ended
	Jun. 30, 2018
Sensitivity analysis for market risk [Abstract]
Methods used in preparing sensitivity analysis reflecting interdependencies between risk variables	The Group performs the sensitivity analyses both for trading and for non-trading activities. For the trading activities, the Group uses a VaR model that uses certain assumptions of possible fluctuations in market conditions and, by conducting simulations of gains and losses, under which the model estimates the maximum losses that may occur. For the non-trading activities, interest rate Earning at Risk (“EaR”) and interest rate VaR, which is based on the simulations of the Net Interest Income (“NII”) and Net Present Value (“NPV”), are calculated for the Bank, and the risks for all other subsidiaries are measured and managed by the interest rate EaR and the interest rate VaR calculations based on the Bank for International Settlements (“BIS”) Framework.
Limitations that may result in information not fully reflecting fair value of assets and liabilities involved	A VaR model predicts based on statistics of possible losses on the portfolio at a certain period currently or in the future. It indicates the maximum expected loss with at least 99% credibility. In short, there exists a one percent possibility that the actual loss might exceed the predicted loss generated from the VaR calculation. The actual results are periodically monitored to examine the validity of the assumptions and variables and factors that are used in VaR calculations. However, this approach cannot prevent the loss when the market fluctuation exceeds expectation.
Methods and assumptions used in preparing sensitivity analysis	A VaR model predicts based on statistics of possible losses on the portfolio at a certain period currently or in the future. It indicates the maximum expected loss with at least 99% credibility. NII is a profit based indicator for displaying profit changes in the short term due to short term interest changes. It will be estimated as subtracting interest expenses of liabilities from the interest income of assets. NPV is an indicator for displaying risks in economic view according to unfavorable changes related to interest rate. It will be estimated as subtracting the present value of liabilities from the present value of assets. EaR shows the maximum profit-loss amount, which indicates the maximum deduction amount caused by the unfavorable changes related to the interest rate of a certain period (i.e. 1 year). Interest rate VaR shows the potential maximum loss generated by the unfavorable changes during a certain period of time in the present or future.

Risk Management_Value at risk a

Risk Management_Value at risk analysis for trading activities (Details) - KRW (₩)	Jun. 30, 2018	Dec. 31, 2017
Fair value concentration of risk market risk management reporting date value at risk [Member]
Value at risk [Line Items]
Total VaR	₩ 5,182,000,000	₩ 5,370,000,000
Fair value concentration of risk market risk management value at risk during year [Member] | Average
Value at risk [Line Items]
Total VaR	6,420,000,000	7,123,000,000
Fair value concentration of risk market risk management value at risk during year [Member] | Maximum
Value at risk [Line Items]
Total VaR	8,614,000,000	9,363,000,000
Fair value concentration of risk market risk management value at risk during year [Member] | Minimum
Value at risk [Line Items]
Total VaR	4,814,000,000	5,370,000,000
Interest rate risk | Fair value concentration of risk market risk management reporting date value at risk [Member]
Value at risk [Line Items]
Total VaR	2,179,000,000	4,183,000,000
Interest rate risk | Fair value concentration of risk market risk management value at risk during year [Member] | Average
Value at risk [Line Items]
Total VaR	3,787,000,000	3,799,000,000
Interest rate risk | Fair value concentration of risk market risk management value at risk during year [Member] | Maximum
Value at risk [Line Items]
Total VaR	4,992,000,000	4,918,000,000
Interest rate risk | Fair value concentration of risk market risk management value at risk during year [Member] | Minimum
Value at risk [Line Items]
Total VaR	1,730,000,000	2,467,000,000
Stock price | Fair value concentration of risk market risk management reporting date value at risk [Member]
Value at risk [Line Items]
Total VaR	2,872,000,000	909,000,000
Stock price | Fair value concentration of risk market risk management value at risk during year [Member] | Average
Value at risk [Line Items]
Total VaR	2,524,000,000	2,863,000,000
Stock price | Fair value concentration of risk market risk management value at risk during year [Member] | Maximum
Value at risk [Line Items]
Total VaR	4,618,000,000	4,419,000,000
Stock price | Fair value concentration of risk market risk management value at risk during year [Member] | Minimum
Value at risk [Line Items]
Total VaR	1,138,000,000	909,000,000
Foreign currencies translation risk | Fair value concentration of risk market risk management reporting date value at risk [Member]
Value at risk [Line Items]
Total VaR	4,224,000,000	4,750,000,000
Foreign currencies translation risk | Fair value concentration of risk market risk management value at risk during year [Member] | Average
Value at risk [Line Items]
Total VaR	4,853,000,000	5,051,000,000
Foreign currencies translation risk | Fair value concentration of risk market risk management value at risk during year [Member] | Maximum
Value at risk [Line Items]
Total VaR	6,136,000,000	6,636,000,000
Foreign currencies translation risk | Fair value concentration of risk market risk management value at risk during year [Member] | Minimum
Value at risk [Line Items]
Total VaR	3,695,000,000	4,061,000,000
Commodity price | Fair value concentration of risk market risk management reporting date value at risk [Member]
Value at risk [Line Items]
Total VaR	2,000,000	0
Commodity price | Fair value concentration of risk market risk management value at risk during year [Member] | Average
Value at risk [Line Items]
Total VaR	1,000,000	31,000,000
Commodity price | Fair value concentration of risk market risk management value at risk during year [Member] | Maximum
Value at risk [Line Items]
Total VaR	4,000,000	188,000,000
Commodity price | Fair value concentration of risk market risk management value at risk during year [Member] | Minimum
Value at risk [Line Items]
Total VaR	0	0
Diversification | Fair value concentration of risk market risk management reporting date value at risk [Member]
Value at risk [Line Items]
Total VaR	(4,095,000,000)	(4,472,000,000)
Diversification | Fair value concentration of risk market risk management value at risk during year [Member] | Average
Value at risk [Line Items]
Total VaR	(4,745,000,000)	(4,621,000,000)
Diversification | Fair value concentration of risk market risk management value at risk during year [Member] | Maximum
Value at risk [Line Items]
Total VaR	(7,136,000,000)	(6,798,000,000)
Diversification | Fair value concentration of risk market risk management value at risk during year [Member] | Minimum
Value at risk [Line Items]
Total VaR	₩ (1,749,000,000)	₩ (2,067,000,000)

Risk management_Scenario respon

Risk management_Scenario responding to IR changes of NII and NPV for assets and liabilities owned by the Bank and consolidated by trusts (Details) - KRW (₩) ₩ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Base case
Sensitivity analysis of market risk for non trading activities [Line Items]
NII	₩ 4,497,407	₩ 4,916,138
NPV	23,856,916	23,472,792
Base case (Prepay)
Sensitivity analysis of market risk for non trading activities [Line Items]
NII	4,491,363	4,916,015
NPV	23,546,002	23,163,942
IR 100bp up
Sensitivity analysis of market risk for non trading activities [Line Items]
NII	5,022,303	5,361,546
NPV	23,803,250	22,886,122
IR 100bp down
Sensitivity analysis of market risk for non trading activities [Line Items]
NII	4,051,601	4,386,437
NPV	23,933,844	24,127,559
IR 200bp up
Sensitivity analysis of market risk for non trading activities [Line Items]
NII	5,992,145	5,806,723
NPV	23,766,488	22,372,208
IR 200bp down
Sensitivity analysis of market risk for non trading activities [Line Items]
NII	3,672,050	3,452,590
NPV	24,043,703	24,830,482
IR 300bp up
Sensitivity analysis of market risk for non trading activities [Line Items]
NII	6,848,435	6,251,897
NPV	23,742,304	21,929,189
IR 300bp down
Sensitivity analysis of market risk for non trading activities [Line Items]
NII	3,527,210	2,254,609
NPV	₩ 24,201,770	₩ 26,633,807

Risk management_Interest EaR an

Risk management_Interest EaR and VaR based on BIS Framework of subsidiaries other than the Bank and consolidated trusts (Details) - KRW (₩) ₩ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Disclosure of sensitivity analysis of market risk for non trading activities of subsidiaries other than bank [Abstract]
EaR	₩ 209,621	₩ 255,679
VaR	₩ 148,818	₩ 130,821

Risk management_Cash flows of n

Risk management_Cash flows of non-trading interest bearing assets and liabilities by repricing date (Details) - KRW (₩) ₩ in Millions	Jun. 30, 2018	Dec. 31, 2017
Asset
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	₩ 296,501,857	₩ 328,925,492
Loans and other financial assets at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	259,148,527
Loans and receivables
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		297,775,378
Financial assets at FVTOCI
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	18,982,136
AFS financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		13,866,019
Securities at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	18,371,194
HTM financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		17,284,095
Liability
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	282,874,437	279,659,987
Deposits due to customers
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	238,018,476	234,879,069
Borrowings
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	16,131,095	14,961,062
Debentures
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	28,724,866	29,819,856
Within 3 months | Asset
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	157,446,946	166,090,779
Within 3 months | Loans and other financial assets at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	148,324,408
Within 3 months | Loans and receivables
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		161,653,892
Within 3 months | Financial assets at FVTOCI
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	6,771,707
Within 3 months | AFS financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		2,150,708
Within 3 months | Securities at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	2,350,831
Within 3 months | HTM financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		2,286,179
Within 3 months | Liability
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	111,737,115	118,636,715
Within 3 months | Deposits due to customers
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	101,367,145	106,815,564
Within 3 months | Borrowings
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	9,390,749	9,865,249
Within 3 months | Debentures
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	979,221	1,955,902
4 to 6 months | Asset
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	46,500,287	46,333,100
4 to 6 months | Loans and other financial assets at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	41,273,662
4 to 6 months | Loans and receivables
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		41,671,530
4 to 6 months | Financial assets at FVTOCI
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	3,243,204
4 to 6 months | AFS financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		2,500,103
4 to 6 months | Securities at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	1,983,421
4 to 6 months | HTM financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		2,161,467
4 to 6 months | Liability
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	52,280,354	41,259,186
4 to 6 months | Deposits due to customers
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	48,458,377	37,750,367
4 to 6 months | Borrowings
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	2,020,828	1,056,579
4 to 6 months | Debentures
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	1,801,149	2,452,240
7 to 9 months | Asset
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	13,000,949	11,064,295
7 to 9 months | Loans and other financial assets at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	9,372,945
7 to 9 months | Loans and receivables
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		7,614,159
7 to 9 months | Financial assets at FVTOCI
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	1,902,718
7 to 9 months | AFS financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		2,016,711
7 to 9 months | Securities at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	1,725,286
7 to 9 months | HTM financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		1,433,425
7 to 9 months | Liability
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	32,998,172	26,549,085
7 to 9 months | Deposits due to customers
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	29,955,015	25,117,556
7 to 9 months | Borrowings
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	859,698	412,966
7 to 9 months | Debentures
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	2,183,459	1,018,563
10 to 12 months | Asset
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	12,292,530	10,466,965
10 to 12 months | Loans and other financial assets at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	8,650,081
10 to 12 months | Loans and receivables
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		6,411,841
10 to 12 months | Financial assets at FVTOCI
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	1,637,346
10 to 12 months | AFS financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		2,367,762
10 to 12 months | Securities at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	2,005,103
10 to 12 months | HTM financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		1,687,362
10 to 12 months | Liability
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	21,950,645	29,775,736
10 to 12 months | Deposits due to customers
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	19,029,698	27,585,458
10 to 12 months | Borrowings
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	513,068	437,431
10 to 12 months | Debentures
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	2,407,879	1,752,847
1 to 5 years | Asset
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	62,414,616	67,749,792
1 to 5 years | Loans and other financial assets at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	47,212,644
1 to 5 years | Loans and receivables
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		54,150,998
1 to 5 years | Financial assets at FVTOCI
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	5,246,163
1 to 5 years | AFS financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		4,229,000
1 to 5 years | Securities at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	9,955,809
1 to 5 years | HTM financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		9,369,794
1 to 5 years | Liability
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	60,361,144	59,998,426
1 to 5 years | Deposits due to customers
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	38,912,199	37,518,878
1 to 5 years | Borrowings
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	2,823,334	2,709,010
1 to 5 years | Debentures
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	18,625,611	19,770,538
Over 5 years | Asset
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	4,846,529	27,220,561
Over 5 years | Loans and other financial assets at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	4,314,787
Over 5 years | Loans and receivables
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		26,272,958
Over 5 years | Financial assets at FVTOCI
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	180,998
Over 5 years | AFS financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		601,735
Over 5 years | Securities at amortized cost
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets	350,744
Over 5 years | HTM financial assets
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing assets		345,868
Over 5 years | Liability
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	3,547,007	3,440,839
Over 5 years | Deposits due to customers
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	296,042	91,246
Over 5 years | Borrowings
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	523,418	479,827
Over 5 years | Debentures
Cash flows of principal and interests from interest baring assets and liabilities [Line Items]
Cash flows of principal and interests from interest bearing liabilities	₩ 2,727,547	₩ 2,869,766

Risk Management_Foreign currenc

Risk Management_Foreign currency risk exposure of financial instruments in foreign currency (Details) $ in Millions	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2018JPY (¥)	Jun. 30, 2018CNY (¥)	Jun. 30, 2018EUR (€)	Dec. 31, 2017KRW (₩)	Dec. 31, 2017USD ($)	Dec. 31, 2017JPY (¥)	Dec. 31, 2017CNY (¥)	Dec. 31, 2017EUR (€)
Won equivalent | Asset
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	₩ 43,254,936,000,000					₩ 38,225,444,000,000
Won equivalent | Loans and other financial assets at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	40,474,753,000,000
Won equivalent | Loans and receivables
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						35,392,763,000,000
Won equivalent | Financial assets at FVTPL (IFRS 9)
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	219,516,000,000					174,016,000,000
Won equivalent | Financial assets at FVTOCI
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	2,325,473,000,000
Won equivalent | AFS financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						2,461,622,000,000
Won equivalent | Securities at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	235,194,000,000
Won equivalent | HTM financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						197,043,000,000
Won equivalent | Liability
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	39,621,498,000,000					39,450,921,000,000
Won equivalent | Financial liabilities at FVTPL
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	221,386,000,000					139,030,000,000
Won equivalent | Deposits due to customer
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	21,950,041,000,000					23,682,896,000,000
Won equivalent | Borrowings
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	8,003,846,000,000					7,659,733,000,000
Won equivalent | Debentures
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	4,443,468,000,000					4,204,715,000,000
Won equivalent | Other financial liabilities
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	5,002,757,000,000					3,764,547,000,000
Won equivalent | Off-balance accounts
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Off balance accounts	9,711,434,000,000					9,899,126,000,000
USD | Foreign currency | Asset
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | $		$ 26,589					$ 25,109
USD | Foreign currency | Loans and other financial assets at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | $		24,664
USD | Foreign currency | Loans and receivables
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | $							23,000
USD | Foreign currency | Financial assets at FVTPL (IFRS 9)
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | $		84					32
USD | Foreign currency | Financial assets at FVTOCI
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | $		1,726
USD | Foreign currency | AFS financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | $							1,966
USD | Foreign currency | Securities at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | $		115
USD | Foreign currency | HTM financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | $							111
USD | Foreign currency | Liability
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | $		24,588					26,248
USD | Foreign currency | Financial liabilities at FVTPL
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | $		63					41
USD | Foreign currency | Deposits due to customer
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | $		11,160					13,744
USD | Foreign currency | Borrowings
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | $		6,417					6,604
USD | Foreign currency | Debentures
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | $		3,708					3,467
USD | Foreign currency | Other financial liabilities
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | $		3,240					2,392
USD | Foreign currency | Off-balance accounts
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Off balance accounts | $		$ 6,374					$ 8,108
USD | Won equivalent | Asset
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	29,854,054,000,000					26,902,043,000,000
USD | Won equivalent | Loans and other financial assets at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	27,694,163,000,000
USD | Won equivalent | Loans and receivables
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						24,642,900,000,000
USD | Won equivalent | Financial assets at FVTPL (IFRS 9)
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	94,261,000,000					34,303,000,000
USD | Won equivalent | Financial assets at FVTOCI
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	1,936,385,000,000
USD | Won equivalent | AFS financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						2,105,972,000,000
USD | Won equivalent | Securities at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	129,245,000,000
USD | Won equivalent | HTM financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						118,868,000,000
USD | Won equivalent | Liability
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	27,582,965,000,000					28,126,378,000,000
USD | Won equivalent | Financial liabilities at FVTPL
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	70,963,000,000					43,423,000,000
USD | Won equivalent | Deposits due to customer
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	12,517,349,000,000					14,725,686,000,000
USD | Won equivalent | Borrowings
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	7,201,536,000,000					7,080,118,000,000
USD | Won equivalent | Debentures
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	4,159,175,000,000					3,714,411,000,000
USD | Won equivalent | Other financial liabilities
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	3,633,942,000,000					2,562,740,000,000
USD | Won equivalent | Off-balance accounts
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Off balance accounts	7,149,273,000,000					8,687,009,000,000
JPY | Foreign currency | Asset
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥			¥ 135,497,000,000					¥ 126,969,000,000
JPY | Foreign currency | Loans and other financial assets at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥			135,138,000,000
JPY | Foreign currency | Loans and receivables
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥								126,944,000,000
JPY | Foreign currency | Financial assets at FVTPL (IFRS 9)
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥			359,000,000					25,000,000
JPY | Foreign currency | Financial assets at FVTOCI
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥			0
JPY | Foreign currency | AFS financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥								0
JPY | Foreign currency | Securities at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥			0
JPY | Foreign currency | HTM financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥								0
JPY | Foreign currency | Liability
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | ¥			171,315,000,000					213,598,000,000
JPY | Foreign currency | Financial liabilities at FVTPL
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | ¥			505,000,000					79,000,000
JPY | Foreign currency | Deposits due to customer
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | ¥			145,058,000,000					195,176,000,000
JPY | Foreign currency | Borrowings
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | ¥			2,211,000,000					2,218,000,000
JPY | Foreign currency | Debentures
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | ¥			0					0
JPY | Foreign currency | Other financial liabilities
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | ¥			23,541,000,000					16,125,000,000
JPY | Foreign currency | Off-balance accounts
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Off balance accounts | ¥			¥ 32,887,000,000					¥ 33,624,000,000
JPY | Won equivalent | Asset
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	1,375,007,000,000					1,205,081,000,000
JPY | Won equivalent | Loans and other financial assets at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	1,371,362,000,000
JPY | Won equivalent | Loans and receivables
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						1,204,843,000,000
JPY | Won equivalent | Financial assets at FVTPL (IFRS 9)
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	3,645,000,000					238,000,000
JPY | Won equivalent | Financial assets at FVTOCI
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	0
JPY | Won equivalent | AFS financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						0
JPY | Won equivalent | Securities at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	0
JPY | Won equivalent | HTM financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						0
JPY | Won equivalent | Liability
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	1,738,490,000,000					2,027,291,000,000
JPY | Won equivalent | Financial liabilities at FVTPL
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	5,127,000,000					752,000,000
JPY | Won equivalent | Deposits due to customer
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	1,472,035,000,000					1,852,440,000,000
JPY | Won equivalent | Borrowings
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	22,438,000,000					21,056,000,000
JPY | Won equivalent | Debentures
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	0					0
JPY | Won equivalent | Other financial liabilities
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	238,890,000,000					153,043,000,000
JPY | Won equivalent | Off-balance accounts
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Off balance accounts	333,730,000,000					319,127,000,000
CNY | Foreign currency | Asset
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥				¥ 32,272,000,000					¥ 25,543,000,000
CNY | Foreign currency | Loans and other financial assets at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥				31,972,000,000
CNY | Foreign currency | Loans and receivables
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥									25,224,000,000
CNY | Foreign currency | Financial assets at FVTPL (IFRS 9)
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥				0					0
CNY | Foreign currency | Financial assets at FVTOCI
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥				300,000,000
CNY | Foreign currency | AFS financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥									319,000,000
CNY | Foreign currency | Securities at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥				0
CNY | Foreign currency | HTM financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | ¥									0
CNY | Foreign currency | Liability
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | ¥				27,201,000,000					24,367,000,000
CNY | Foreign currency | Financial liabilities at FVTPL
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | ¥				0					0
CNY | Foreign currency | Deposits due to customer
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | ¥				21,633,000,000					21,865,000,000
CNY | Foreign currency | Borrowings
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | ¥				0					0
CNY | Foreign currency | Debentures
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | ¥				0					700,000,000
CNY | Foreign currency | Other financial liabilities
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | ¥				5,568,000,000					1,802,000,000
CNY | Foreign currency | Off-balance accounts
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Off balance accounts | ¥				¥ 4,804,000,000					¥ 1,199,000,000
CNY | Won equivalent | Asset
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	5,467,168,000,000					4,180,195,000,000
CNY | Won equivalent | Loans and other financial assets at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	5,416,294,000,000
CNY | Won equivalent | Loans and receivables
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						4,127,936,000,000
CNY | Won equivalent | Financial assets at FVTPL (IFRS 9)
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	0					0
CNY | Won equivalent | Financial assets at FVTOCI
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	50,874,000,000
CNY | Won equivalent | AFS financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						52,259,000,000
CNY | Won equivalent | Securities at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	0
CNY | Won equivalent | HTM financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						0
CNY | Won equivalent | Liability
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	4,608,163,000,000					3,987,647,000,000
CNY | Won equivalent | Financial liabilities at FVTPL
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	0					0
CNY | Won equivalent | Deposits due to customer
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	3,664,842,000,000					3,578,142,000,000
CNY | Won equivalent | Borrowings
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	0					0
CNY | Won equivalent | Debentures
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	0					114,555,000,000
CNY | Won equivalent | Other financial liabilities
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	943,321,000,000					294,950,000,000
CNY | Won equivalent | Off-balance accounts
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Off balance accounts	813,812,000,000					196,261,000,000
EUR | Foreign currency | Asset
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | €					€ 1,208,000,000					€ 1,183,000,000
EUR | Foreign currency | Loans and other financial assets at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | €					1,172,000,000
EUR | Foreign currency | Loans and receivables
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | €										1,156,000,000
EUR | Foreign currency | Financial assets at FVTPL (IFRS 9)
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | €					36,000,000					27,000,000
EUR | Foreign currency | Financial assets at FVTOCI
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | €					0
EUR | Foreign currency | AFS financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | €										0
EUR | Foreign currency | Securities at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | €					0
EUR | Foreign currency | HTM financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies | €										0
EUR | Foreign currency | Liability
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | €					1,635,000,000					1,278,000,000
EUR | Foreign currency | Financial liabilities at FVTPL
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | €					33,000,000					19,000,000
EUR | Foreign currency | Deposits due to customer
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | €					1,230,000,000					883,000,000
EUR | Foreign currency | Borrowings
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | €					232,000,000					247,000,000
EUR | Foreign currency | Debentures
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | €					0					0
EUR | Foreign currency | Other financial liabilities
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies | €					140,000,000					129,000,000
EUR | Foreign currency | Off-balance accounts
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Off balance accounts | €					€ 453,000,000					€ 406,000,000
EUR | Won equivalent | Asset
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	1,566,532,000,000					1,514,524,000,000
EUR | Won equivalent | Loans and other financial assets at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	1,520,044,000,000
EUR | Won equivalent | Loans and receivables
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						1,479,351,000,000
EUR | Won equivalent | Financial assets at FVTPL (IFRS 9)
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	46,488,000,000					34,583,000,000
EUR | Won equivalent | Financial assets at FVTOCI
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	0
EUR | Won equivalent | AFS financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						590,000,000
EUR | Won equivalent | Securities at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	0
EUR | Won equivalent | HTM financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						0
EUR | Won equivalent | Liability
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	2,123,724,000,000					1,635,554,000,000
EUR | Won equivalent | Financial liabilities at FVTPL
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	43,070,000,000					24,878,000,000
EUR | Won equivalent | Deposits due to customer
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	1,595,651,000,000					1,129,802,000,000
EUR | Won equivalent | Borrowings
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	303,001,000,000					315,685,000,000
EUR | Won equivalent | Debentures
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	0					0
EUR | Won equivalent | Other financial liabilities
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	182,002,000,000					165,189,000,000
EUR | Won equivalent | Off-balance accounts
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Off balance accounts	587,615,000,000					519,843,000,000
Others | Won equivalent | Asset
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	4,992,175,000,000					4,423,601,000,000
Others | Won equivalent | Loans and other financial assets at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	4,472,890,000,000
Others | Won equivalent | Loans and receivables
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						3,937,733,000,000
Others | Won equivalent | Financial assets at FVTPL (IFRS 9)
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	75,122,000,000					104,892,000,000
Others | Won equivalent | Financial assets at FVTOCI
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	338,214,000,000
Others | Won equivalent | AFS financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						302,801,000,000
Others | Won equivalent | Securities at amortized cost
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies	105,949,000,000
Others | Won equivalent | HTM financial assets
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial assets denominated in foregin currencies						78,175,000,000
Others | Won equivalent | Liability
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	3,568,156,000,000					3,674,051,000,000
Others | Won equivalent | Financial liabilities at FVTPL
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	102,226,000,000					69,977,000,000
Others | Won equivalent | Deposits due to customer
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	2,700,164,000,000					2,396,826,000,000
Others | Won equivalent | Borrowings
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	476,871,000,000					242,874,000,000
Others | Won equivalent | Debentures
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	284,293,000,000					375,749,000,000
Others | Won equivalent | Other financial liabilities
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Financial liabilities denominated in foregin currencies	4,602,000,000					588,625,000,000
Others | Won equivalent | Off-balance accounts
Financial statement lineitems with diffrences in reported amount and reporting currency denominated amounts [Line Items]
Off balance accounts	₩ 827,004,000,000					₩ 176,886,000,000

Risk Management_Cash flow from

Risk Management_Cash flow from principal and interest payments of nonderivative financial liabilities by remaining contractual maturities (Details) - KRW (₩)	Jun. 30, 2018	Dec. 31, 2017
Disclosure of maturity analysis for derivative financial liabilities by remaining contractual maturity [Line Items]
Financial liabilities at FVTPL	₩ 176,097,000,000	₩ 327,030,000,000
Deposits due to customers	240,721,692,000,000	238,249,257,000,000
Borrowings	16,184,965,000,000	15,080,533,000,000
Debentures	28,724,866,000,000	29,811,344,000,000
Other financial liabilities	16,896,806,000,000	10,144,982,000,000
Total	302,704,426,000,000	293,613,146,000,000
Within 3 months
Disclosure of maturity analysis for derivative financial liabilities by remaining contractual maturity [Line Items]
Financial liabilities at FVTPL	176,097,000,000	168,442,000,000
Deposits due to customers	145,033,422,000,000	148,008,777,000,000
Borrowings	6,407,137,000,000	6,115,732,000,000
Debentures	979,221,000,000	1,955,255,000,000
Other financial liabilities	14,098,508,000,000	7,121,342,000,000
Total	166,694,385,000,000	163,369,548,000,000
4 to 6 months
Disclosure of maturity analysis for derivative financial liabilities by remaining contractual maturity [Line Items]
Financial liabilities at FVTPL	0	155,984,000,000
Deposits due to customers	38,505,386,000,000	29,563,310,000,000
Borrowings	2,639,064,000,000	1,893,173,000,000
Debentures	1,801,149,000,000	2,452,565,000,000
Other financial liabilities	216,627,000,000	162,871,000,000
Total	43,162,226,000,000	34,227,903,000,000
7 to 9 months
Disclosure of maturity analysis for derivative financial liabilities by remaining contractual maturity [Line Items]
Financial liabilities at FVTPL	0	1,717,000,000
Deposits due to customers	22,976,591,000,000	18,175,348,000,000
Borrowings	1,876,893,000,000	1,489,272,000,000
Debentures	2,183,459,000,000	1,018,714,000,000
Other financial liabilities	3,644,000,000	825,000,000
Total	27,040,587,000,000	20,685,876,000,000
10 to 12 months
Disclosure of maturity analysis for derivative financial liabilities by remaining contractual maturity [Line Items]
Financial liabilities at FVTPL	0	512,000,000
Deposits due to customers	24,574,059,000,000	32,468,110,000,000
Borrowings	1,478,115,000,000	1,178,107,000,000
Debentures	2,407,879,000,000	1,744,731,000,000
Other financial liabilities	908,000,000	1,003,000,000
Total	28,460,961,000,000	35,392,463,000,000
1 to 5 years
Disclosure of maturity analysis for derivative financial liabilities by remaining contractual maturity [Line Items]
Financial liabilities at FVTPL	0	375,000,000
Deposits due to customers	7,487,432,000,000	7,409,118,000,000
Borrowings	3,238,353,000,000	3,924,681,000,000
Debentures	18,626,696,000,000	19,770,380,000,000
Other financial liabilities	621,127,000,000	128,940,000,000
Total	29,973,608,000,000	31,233,494,000,000
Over 5 years
Disclosure of maturity analysis for derivative financial liabilities by remaining contractual maturity [Line Items]
Financial liabilities at FVTPL	0	0
Deposits due to customers	2,144,802,000,000	2,624,594,000,000
Borrowings	545,403,000,000	479,568,000,000
Debentures	2,726,462,000,000	2,869,699,000,000
Other financial liabilities	1,955,992,000,000	2,730,001,000,000
Total	₩ 7,372,659,000,000	₩ 8,703,862,000,000

Risk Management_Cash flow fr130

Risk Management_Cash flow from principal and interest payments of nonderivative financial liabilities by estimated redemption or withdrawal (Details) - KRW (₩)	Jun. 30, 2018	Dec. 31, 2017
Disclosure of maturity analysis for derivative financial liabilities by estimated redemption or withdrawal [Line Items]
Financial liabilities at FVTPL	₩ 176,097,000,000	₩ 327,030,000,000
Deposits due to customers	240,114,053,000,000	237,873,391,000,000
Borrowings	16,184,965,000,000	15,080,533,000,000
Debentures	28,724,866,000,000	29,811,344,000,000
Other financial liabilities	16,896,806,000,000	10,144,982,000,000
Total	302,096,787,000,000	293,237,280,000,000
Within 3 months
Disclosure of maturity analysis for derivative financial liabilities by estimated redemption or withdrawal [Line Items]
Financial liabilities at FVTPL	176,097,000,000	168,442,000,000
Deposits due to customers	154,934,637,000,000	159,146,602,000,000
Borrowings	6,407,137,000,000	6,115,732,000,000
Debentures	979,221,000,000	1,955,255,000,000
Other financial liabilities	14,098,508,000,000	7,121,342,000,000
Total	176,595,600,000,000	174,507,373,000,000
4 to 6 months
Disclosure of maturity analysis for derivative financial liabilities by estimated redemption or withdrawal [Line Items]
Financial liabilities at FVTPL	0	155,984,000,000
Deposits due to customers	40,340,567,000,000	31,298,562,000,000
Borrowings	2,639,064,000,000	1,893,173,000,000
Debentures	1,801,149,000,000	2,452,565,000,000
Other financial liabilities	216,627,000,000	162,871,000,000
Total	44,997,407,000,000	35,963,155,000,000
7 to 9 months
Disclosure of maturity analysis for derivative financial liabilities by estimated redemption or withdrawal [Line Items]
Financial liabilities at FVTPL	0	1,717,000,000
Deposits due to customers	20,220,152,000,000	16,667,130,000,000
Borrowings	1,876,893,000,000	1,489,272,000,000
Debentures	2,183,459,000,000	1,018,714,000,000
Other financial liabilities	3,644,000,000	825,000,000
Total	24,284,148,000,000	19,177,658,000,000
10 to 12 months
Disclosure of maturity analysis for derivative financial liabilities by estimated redemption or withdrawal [Line Items]
Financial liabilities at FVTPL	0	512,000,000
Deposits due to customers	18,154,029,000,000	21,995,294,000,000
Borrowings	1,478,115,000,000	1,178,107,000,000
Debentures	2,407,879,000,000	1,744,731,000,000
Other financial liabilities	908,000,000	1,003,000,000
Total	22,040,931,000,000	24,919,647,000,000
1 to 5 years
Disclosure of maturity analysis for derivative financial liabilities by estimated redemption or withdrawal [Line Items]
Financial liabilities at FVTPL	0	375,000,000
Deposits due to customers	6,115,894,000,000	6,487,047,000,000
Borrowings	3,242,839,000,000	3,924,681,000,000
Debentures	18,626,696,000,000	19,770,380,000,000
Other financial liabilities	621,127,000,000	128,940,000,000
Total	28,606,556,000,000	30,311,423,000,000
Over 5 years
Disclosure of maturity analysis for derivative financial liabilities by estimated redemption or withdrawal [Line Items]
Financial liabilities at FVTPL	0	0
Deposits due to customers	348,774,000,000	2,278,756,000,000
Borrowings	540,917,000,000	479,568,000,000
Debentures	2,726,462,000,000	2,869,699,000,000
Other financial liabilities	1,955,992,000,000	2,730,001,000,000
Total	₩ 5,572,145,000,000	₩ 8,358,024,000,000

Risk Management_Cash flow of de

Risk Management_Cash flow of derivative financial liabilities by maturities (Details) - KRW (₩)	Jun. 30, 2018	Dec. 31, 2017
Disclosure of maturity analysis for derivative financial liabilities [Line Items]
Cash flow to be paid of total settlement derivatives	₩ 2,445,255,000,000	₩ 3,217,903,000,000
Within 3 months
Disclosure of maturity analysis for derivative financial liabilities [Line Items]
Cash flow to be paid of total settlement derivatives	2,377,750,000,000	3,150,149,000,000
4 to 6 months
Disclosure of maturity analysis for derivative financial liabilities [Line Items]
Cash flow to be paid of total settlement derivatives	2,130,000,000	0
7 to 9 months
Disclosure of maturity analysis for derivative financial liabilities [Line Items]
Cash flow to be paid of total settlement derivatives	0	0
10 to 12 months
Disclosure of maturity analysis for derivative financial liabilities [Line Items]
Cash flow to be paid of total settlement derivatives	0	381,000,000
1 to 5 years
Disclosure of maturity analysis for derivative financial liabilities [Line Items]
Cash flow to be paid of total settlement derivatives	59,820,000,000	67,373,000,000
Over 5 years
Disclosure of maturity analysis for derivative financial liabilities [Line Items]
Cash flow to be paid of total settlement derivatives	₩ 5,555,000,000	₩ 0

Risk Management_Maturity analys

Risk Management_Maturity analysis of Offbalance accounts (Details) - KRW (₩) ₩ in Millions	Jun. 30, 2018	Dec. 31, 2017
Disclosure of maturity analysis for off balance sheet item [Abstract]
Guarantees	₩ 12,372,573	₩ 12,859,715
Loan commitments	₩ 98,251,006	₩ 80,760,325

Risk Management_Capital Ratio (

Risk Management_Capital Ratio (Details) - KRW (₩) ₩ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2018		Dec. 31, 2017
Disclosure of objectives policies and processes for managing capital [Abstract]
Minimum common equity tier one ratio	7.13%		6.25%
Minimum tier one ratio	8.63%		7.75%
Minimum total regulatory capital ratio	10.63%		9.75%
Summary of quantitative data about what entity manages as capital	The Group is required to meet the following new minimum requirements: Common Equity Tier 1 capital ratio of 7.13% and 6.25%, a minimum Tier 1 ratio of 8.63% and 7.75% and a minimum total regulatory capital of 10.63% and 9.75% as of June 30, 2018 and December 31, 2017, respectively.		The Group is required to meet the following new minimum requirements: Common Equity Tier 1 capital ratio of 7.13% and 6.25%, a minimum Tier 1 ratio of 8.63% and 7.75% and a minimum total regulatory capital of 10.63% and 9.75% as of June 30, 2018 and December 31, 2017, respectively.
Qualitative information about entitys objectives policies and processes for managing capital	The Group complies with the standard of capital adequacy provided by financial regulatory authorities. The capital adequacy standard is based on Basel III of Basel Committee on Banking Supervision and Basel III was applied from the end of December, 2013. The capital adequacy ratio is calculated by dividing own capital by asset (weighted with a risk premium – risk weighted assets) based on the consolidated financial statements of the Group.		The Group complies with the standard of capital adequacy provided by financial regulatory authorities. The capital adequacy standard is based on Basel III of Basel Committee on Banking Supervision and Basel III was applied from the end of December, 2013. The capital adequacy ratio is calculated by dividing own capital by asset (weighted with a risk premium – risk weighted assets) based on the consolidated financial statements of the Group.
Tier one risk based capital [Abstract]
Tier 1 capital	₩ 16,952,436		₩ 16,074,987
Other Tier 1 capital	2,748,005		3,041,664
Tier 2 capital	3,499,122		3,486,555
Total risk adjusted capital	23,199,563		22,603,206
Risk weighted assets for credit risk	139,868,803		134,767,711
Risk weighted assets for market risk	2,292,979		2,316,938
Risk weighted assets for operational risk	9,826,809		9,677,559
Total risk weighted assets	₩ 151,988,591		₩ 146,762,208
Common Equity Tier 1 ratio	11.15%	[1]	10.95%
Tier 1 capital ratio	12.96%	[1]	13.03%
Total capital ratio	15.26%	[1]	15.40%
[1]	Capital adequacy ratio as of June 30, 2018 is tentatively measured.

Operating Segments_Segment by t

Operating Segments_Segment by types of customers (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018KRW (₩)	Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Inter segment transaction [Line Items]
Assets	₩ 326,561,330,000,000		₩ 326,561,330,000,000			$ 293,723,089	₩ 316,295,461,000,000
Liabilities	305,564,719,000,000		305,564,719,000,000			$ 274,837,848	₩ 295,730,561,000,000
Net interest income	1,397,323,000,000	₩ 1,287,576,000,000	2,764,474,000,000	$ 2,486,485	₩ 2,550,320,000,000
Interest income	2,368,669,000,000	2,105,808,000,000	4,643,416,000,000	4,176,485	4,189,584,000,000
Interest expense	(971,346,000,000)	(818,232,000,000)	(1,878,942,000,000)	(1,690,000)	(1,639,264,000,000)
Inter-segment			0		0
Net non-interest income			585,263,000,000		588,128,000,000
Non-interest income			6,625,267,000,000		7,530,641,000,000
Non-interest expense			(6,040,004,000,000)		(6,942,513,000,000)
Inter-segment			0		0
Other income(expense)			(1,542,022,000,000)		(1,654,220,000,000)
General and administrative expenses	(827,654,000,000)	(784,157,000,000)	(1,567,338,000,000)	(1,409,730)	(1,538,427,000,000)
Reversal of allowance for credit loss and impairment losses due to credit loss			25,316,000,000		(115,793,000,000)
Operating income	986,418,000,000	604,484,000,000	1,807,715,000,000	1,625,935	1,484,228,000,000
Non operating income(expense)	9,079,000,000	(3,166,000,000)	(6,183,000,000)	(5,561)	(54,280,000,000)
Net income before income tax expense	995,497,000,000	601,318,000,000	1,801,532,000,000	1,620,374	1,429,948,000,000
Income tax expense	(273,701,000,000)	(135,034,000,000)	(485,216,000,000)	(436,424)	(320,933,000,000)
Net income	₩ 721,796,000,000	₩ 466,284,000,000	₩ 1,316,316,000,000	$ 1,183,950	₩ 1,109,015,000,000
Factors used to identify entitys reportable segments			The Group’s reporting segments comprise the following customers: consumer banking, corporate banking, investment banking, capital market, credit card market and headquarters and others. The reportable segments are classified based on the target customers for whom the service is being provided.	The Group’s reporting segments comprise the following customers: consumer banking, corporate banking, investment banking, capital market, credit card market and headquarters and others. The reportable segments are classified based on the target customers for whom the service is being provided.	The Group’s reporting segments comprise the following customers: consumer banking, corporate banking, investment banking, capital market, credit card market and headquarters and others. The reportable segments are classified based on the target customers for whom the service is being provided.
Operating segments [Member]
Inter segment transaction [Line Items]
Net interest income			₩ 2,464,770,000,000		₩ 2,257,978,000,000
Interest income			4,493,664,000,000		4,034,389,000,000
Interest expense			(2,028,894,000,000)		(1,776,411,000,000)
Inter-segment			0		0
Net non-interest income			1,003,673,000,000		955,359,000,000
Non-interest income			6,861,536,000,000		7,657,368,000,000
Non-interest expense			(5,857,863,000,000)		(6,702,009,000,000)
Inter-segment			0		0
Other income(expense)			(1,648,884,000,000)		(1,737,362,000,000)
General and administrative expenses			(1,702,904,000,000)		(1,662,297,000,000)
Reversal of allowance for credit loss and impairment losses due to credit loss			54,020,000,000		(75,065,000,000)
Operating income			1,819,559,000,000		1,475,975,000,000
Non operating income(expense)			22,820,000,000		(258,000,000)
Net income before income tax expense			1,842,379,000,000		1,475,717,000,000
Income tax expense			(486,164,000,000)		(312,855,000,000)
Net income			1,356,215,000,000		1,162,862,000,000
Consumer banking
Inter segment transaction [Line Items]
Net interest income			929,286,000,000		810,799,000,000
Interest income			1,703,521,000,000		1,539,729,000,000
Interest expense			(499,830,000,000)		(480,814,000,000)
Inter-segment			(274,405,000,000)		(248,116,000,000)
Net non-interest income			356,310,000,000		322,986,000,000
Non-interest income			405,145,000,000		424,214,000,000
Non-interest expense			(127,357,000,000)		(146,630,000,000)
Inter-segment			78,522,000,000		45,402,000,000
Other income(expense)			(928,336,000,000)		(915,696,000,000)
General and administrative expenses			(875,328,000,000)		(869,732,000,000)
Reversal of allowance for credit loss and impairment losses due to credit loss			(53,008,000,000)		(45,964,000,000)
Operating income			357,260,000,000		218,089,000,000
Non operating income(expense)			(9,889,000,000)		8,862,000,000
Net income before income tax expense			347,371,000,000		226,951,000,000
Income tax expense			(95,528,000,000)		(54,923,000,000)
Net income			₩ 251,843,000,000		₩ 172,028,000,000
Factors used to identify entitys reportable segments			• Consumer banking: Loans/deposits and financial services for retail and individual consumers, etc.	• Consumer banking: Loans/deposits and financial services for retail and individual consumers, etc.	• Consumer banking: Loans/deposits and financial services for retail and individual consumers, etc.
Corporate banking
Inter segment transaction [Line Items]
Net interest income			₩ 967,363,000,000		₩ 866,805,000,000
Interest income			1,638,747,000,000		1,456,198,000,000
Interest expense			(994,523,000,000)		(818,422,000,000)
Inter-segment			323,139,000,000		229,029,000,000
Net non-interest income			284,855,000,000		281,065,000,000
Non-interest income			432,262,000,000		333,646,000,000
Non-interest expense			(183,814,000,000)		(82,261,000,000)
Inter-segment			36,407,000,000		29,680,000,000
Other income(expense)			(293,933,000,000)		(531,346,000,000)
General and administrative expenses			(403,216,000,000)		(402,661,000,000)
Reversal of allowance for credit loss and impairment losses due to credit loss			109,283,000,000		(128,685,000,000)
Operating income			958,285,000,000		616,524,000,000
Non operating income(expense)			671,000,000		(3,122,000,000)
Net income before income tax expense			958,956,000,000		613,402,000,000
Income tax expense			(260,186,000,000)		(139,138,000,000)
Net income			₩ 698,770,000,000		₩ 474,264,000,000
Factors used to identify entitys reportable segments			• Corporate banking: Loans/deposits and export/import, financial services for corporations, etc.	• Corporate banking: Loans/deposits and export/import, financial services for corporations, etc.	• Corporate banking: Loans/deposits and export/import, financial services for corporations, etc.
Investment banking
Inter segment transaction [Line Items]
Net interest income			₩ (3,078,000,000)		₩ 5,413,000,000
Interest income			74,670,000,000		72,232,000,000
Interest expense			(92,000,000)		(126,000,000)
Inter-segment			(77,656,000,000)		(66,693,000,000)
Net non-interest income			96,843,000,000		90,869,000,000
Non-interest income			137,031,000,000		212,107,000,000
Non-interest expense			(40,188,000,000)		(121,238,000,000)
Inter-segment			0		0
Other income(expense)			46,555,000,000		25,615,000,000
General and administrative expenses			(5,689,000,000)		(5,696,000,000)
Reversal of allowance for credit loss and impairment losses due to credit loss			52,244,000,000		31,311,000,000
Operating income			140,320,000,000		121,897,000,000
Non operating income(expense)			17,411,000,000		22,581,000,000
Net income before income tax expense			157,731,000,000		144,478,000,000
Income tax expense			(43,377,000,000)		(34,964,000,000)
Net income			₩ 114,354,000,000		₩ 109,514,000,000
Factors used to identify entitys reportable segments			• Investment banking: Domestic/foreign investment, structured finance, M&A, equity & fund investment related business, venture advisory related tasks, real estate SOC development practices, etc.	• Investment banking: Domestic/foreign investment, structured finance, M&A, equity & fund investment related business, venture advisory related tasks, real estate SOC development practices, etc.	• Investment banking: Domestic/foreign investment, structured finance, M&A, equity & fund investment related business, venture advisory related tasks, real estate SOC development practices, etc.
Capital market
Inter segment transaction [Line Items]
Net interest income			₩ 15,946,000,000		₩ 17,262,000,000
Interest income			5,687,000,000		8,938,000,000
Interest expense			0		0
Inter-segment			10,259,000,000		8,324,000,000
Net non-interest income			39,583,000,000		22,758,000,000
Non-interest income			4,765,167,000,000		4,991,598,000,000
Non-interest expense			(4,725,584,000,000)		(4,968,840,000,000)
Inter-segment			0		0
Other income(expense)			(11,120,000,000)		14,414,000,000
General and administrative expenses			(7,852,000,000)		(7,721,000,000)
Reversal of allowance for credit loss and impairment losses due to credit loss			(3,268,000,000)		22,135,000,000
Operating income			44,409,000,000		54,434,000,000
Non operating income(expense)			0		0
Net income before income tax expense			44,409,000,000		54,434,000,000
Income tax expense			(12,212,000,000)		(13,173,000,000)
Net income			₩ 32,197,000,000		₩ 41,261,000,000
Factors used to identify entitys reportable segments			• Capital market: Fund management, investment in securities and derivatives, etc	• Capital market: Fund management, investment in securities and derivatives, etc	• Capital market: Fund management, investment in securities and derivatives, etc
Credit Card
Inter segment transaction [Line Items]
Net interest income			₩ 247,727,000,000		₩ 223,048,000,000
Interest income			323,443,000,000		288,648,000,000
Interest expense			(75,716,000,000)		(65,600,000,000)
Inter-segment			0		0
Net non-interest income			42,955,000,000		45,638,000,000
Non-interest income			605,165,000,000		566,107,000,000
Non-interest expense			(562,210,000,000)		(520,469,000,000)
Inter-segment			0		0
Other income(expense)			(197,535,000,000)		(184,607,000,000)
General and administrative expenses			(83,575,000,000)		(77,909,000,000)
Reversal of allowance for credit loss and impairment losses due to credit loss			(113,960,000,000)		(106,698,000,000)
Operating income			93,147,000,000		84,079,000,000
Non operating income(expense)			(2,988,000,000)		(2,399,000,000)
Net income before income tax expense			90,159,000,000		81,680,000,000
Income tax expense			(22,541,000,000)		(19,816,000,000)
Net income			₩ 67,618,000,000		₩ 61,864,000,000
Factors used to identify entitys reportable segments			• Credit card: Credit card, cash service and card loan, etc.	• Credit card: Credit card, cash service and card loan, etc.	• Credit card: Credit card, cash service and card loan, etc.
Headquarter and Others
Inter segment transaction [Line Items]
Net interest income			₩ 307,526,000,000		₩ 334,651,000,000
Interest income			747,596,000,000		668,644,000,000
Interest expense			(458,733,000,000)		(411,449,000,000)
Inter-segment			18,663,000,000		77,456,000,000
Net non-interest income			183,127,000,000		192,043,000,000
Non-interest income			516,766,000,000		1,129,696,000,000
Non-interest expense			(218,710,000,000)		(862,571,000,000)
Inter-segment			(114,929,000,000)		(75,082,000,000)
Other income(expense)			(264,515,000,000)		(145,742,000,000)
General and administrative expenses			(327,244,000,000)		(298,578,000,000)
Reversal of allowance for credit loss and impairment losses due to credit loss			62,729,000,000		152,836,000,000
Operating income			226,138,000,000		380,952,000,000
Non operating income(expense)			17,615,000,000		(26,180,000,000)
Net income before income tax expense			243,753,000,000		354,772,000,000
Income tax expense			(52,320,000,000)		(50,841,000,000)
Net income			₩ 191,433,000,000		₩ 303,931,000,000
Factors used to identify entitys reportable segments			• Headquarter and others: Segments that do not belong to above operating segments	• Headquarter and others: Segments that do not belong to above operating segments	• Headquarter and others: Segments that do not belong to above operating segments
Inter segment transaction
Inter segment transaction [Line Items]
Net interest income			₩ 299,704,000,000		₩ 292,342,000,000
Interest income			149,752,000,000		155,195,000,000
Interest expense			149,952,000,000		137,147,000,000
Inter-segment			0		0
Net non-interest income			(418,410,000,000)		(367,231,000,000)
Non-interest income			(236,269,000,000)		(126,727,000,000)
Non-interest expense			(182,141,000,000)		(240,504,000,000)
Inter-segment			0		0
Other income(expense)			106,862,000,000		83,142,000,000
General and administrative expenses			135,566,000,000		123,870,000,000
Reversal of allowance for credit loss and impairment losses due to credit loss			(28,704,000,000)		(40,728,000,000)
Operating income			(11,844,000,000)		8,253,000,000
Non operating income(expense)			(29,003,000,000)		(54,022,000,000)
Net income before income tax expense			(40,847,000,000)		(45,769,000,000)
Income tax expense			948,000,000		(8,078,000,000)
Net income			₩ (39,899,000,000)		₩ (53,847,000,000)

Operating Segments_Information

Operating Segments_Information on products and services (Details)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Disclosure of products and services [Abstract]
Description of information on products and services	The products of the Group are classified as interest-bearing products such as loans, deposits and debt securities and non-interest bearing products such as loan commitment, credit commitment, equity securities, and credit card service. This classification of products has been reflected in the segment information presenting interest income and non-interest income.	The products of the Group are classified as interest-bearing products such as loans, deposits and debt securities and non-interest bearing products such as loan commitment, credit commitment, equity securities, and credit card service. This classification of products has been reflected in the segment information presenting interest income and non-interest income.

Operating Segments_Informati136

Operating Segments_Information on geographical areas (Details) - KRW (₩) ₩ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Domestic customers
Disclosure of geographical areas [Line Items]
Revenue	₩ 10,626,155	₩ 11,185,991
Non-current assets	3,664,521		₩ 3,550,764
Foreign customers
Disclosure of geographical areas [Line Items]
Revenue	642,528	₩ 534,234
Non-current assets	₩ 233,864		₩ 233,732

Cash and cash equivalents_Detai

Cash and cash equivalents_Details of cash and cash equivalents (Details) $ in Thousands, ₩ in Millions	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)	Dec. 31, 2017USD ($)	Jun. 30, 2017KRW (₩)	Dec. 31, 2016KRW (₩)
Cash and cash equivalents [Abstract]
Cash	₩ 1,889,739		₩ 2,009,363
Foreign currencies	795,692		617,155
Demand deposits	2,777,874		3,423,355
Fixed deposits	457,263		858,413
Total	₩ 5,920,568	$ 5,325,210	₩ 6,908,286	$ 6,213,605	₩ 7,377,124	₩ 7,591,324

Cash and cash equivalents_Signi

Cash and cash equivalents_Significant non-cash transactions (Details) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2018KRW (₩)		Jun. 30, 2017KRW (₩)		Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Cash flow noncash investing and financing activities disclosure [Abstract]
Changes in other comprehensive gain due to remeasurement of financial assets designated at FVTOCI					₩ 41,452,000,000	[1]	$ 37,284	₩ 0
Changes in other comprehensive loss due to valuation of AFS financial assets	₩ 0		₩ (41,680,000,000)		0			(28,706,000,000)
Changes in other comprehensive income and loss of investment in associates					1,210,000,000			1,507,000,000
Changes in other comprehensive gain (loss) of foreign operations translation	37,268,000,000		31,450,000,000		35,526,000,000		31,954	(69,010,000,000)
Changes in other comprehensive loss related to valuation of cash flow hedging	(2,787,000,000)		(673,000,000)		(6,213,000,000)		(5,588)	(1,526,000,000)
Changes in other comprehensive loss due to remeasurement of the net defined benefit liability	(6,113,000,000)		16,840,000,000		(59,573,000,000)		$ (53,583)	(9,677,000,000)
Changes in investments in associates due to equity swap	0		51,405,000,000	[2]	0			51,405,000,000	[2]
Changes in investments in associates due to accounts transfer	(5,865,000,000)	[3]	(16,354,000,000)	[4]	(5,865,000,000)	[3]		(16,354,000,000)	[4]
Changes in accrued dividends of hybrid equity securities					(80,000,000)			(9,804,000,000)
Changes in intangible assets related to accounts payable	32,369,000,000		(8,506,000,000)		32,369,000,000			(8,506,000,000)
Classified to assets held for sale from premises and equipment	₩ 6,050,000,000		₩ 2,184,000,000		₩ 6,050,000,000			₩ 2,184,000,000
[1]	The consolidated interim statements of changes in equity for the six months ended June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated interim statements of changes in equity for the six months ended June 30, 2017 was not retrospectively restated in accordance with IFRS 9.
[2]	Changes in investments in joint ventures and associates due to debt-equity swap is 51,405 million Won.
[3]	Investments in joint ventures and associates decreased by 5,865 million Won through transfers to assets held for sale which occurred during the six months ended June 30, 2018.
[4]	Investments in joint ventures and associates decreased by 16,354 million Won through transfers to assets held for sale occurred for the six months ended June 30, 2017.

Financial assets at FVTPL_Detai

Financial assets at FVTPL_Details of financial assets at FVTPL (Details)	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)		Dec. 31, 2017KRW (₩)
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL mandatorily measured at fair value (IFRS 9)	₩ 6,340,704,000,000
Financial assets at FVTPL	6,340,704,000,000	[1]	$ 5,703,098,000	[1]	₩ 0
Financial assets held for trading (IAS 39)	0				5,820,787,000,000
Financial assets designated at FVTPL (IAS 39)	0				22,290,000,000
Financial assets at FVTPL (IAS 39)	0		$ 0		5,843,077,000,000
Deposits
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL	24,921,000,000
Financial assets at FVTPL (IAS 39)					25,972,000,000
Deposits indexed to gold prices
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL mandatorily measured at fair value (IFRS 9)	24,921,000,000
Financial assets held for trading (IAS 39)					25,972,000,000
Securities
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL mandatorily measured at fair value (IFRS 9)	3,587,605,000,000
Financial assets held for trading (IAS 39)					2,679,040,000,000
Korean treasury and government agencies
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL mandatorily measured at fair value (IFRS 9)	639,476,000,000
Financial assets held for trading (IAS 39)					540,438,000,000
Financial institutions
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL mandatorily measured at fair value (IFRS 9)	639,711,000,000
Financial assets held for trading (IAS 39)					1,476,498,000,000
Corporates
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL mandatorily measured at fair value (IFRS 9)	714,508,000,000
Financial assets held for trading (IAS 39)					627,397,000,000
Others
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL mandatorily measured at fair value (IFRS 9)	156,000,000
Financial assets held for trading (IAS 39)					0
Equity securities
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL mandatorily measured at fair value (IFRS 9)	433,316,000,000
Financial assets held for trading (IAS 39)					21,666,000,000
Capital contributions
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL mandatorily measured at fair value (IFRS 9)	349,470,000,000
Financial assets held for trading (IAS 39)					0
Beneficiary certificates
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL mandatorily measured at fair value (IFRS 9)	810,968,000,000
Financial assets held for trading (IAS 39)					13,041,000,000
Loans
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL mandatorily measured at fair value (IFRS 9)	336,967,000,000
Financial assets held for trading (IAS 39)					0
Derivatives instruments assets
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets at FVTPL mandatorily measured at fair value (IFRS 9)	2,391,211,000,000
Financial assets at FVTPL	₩ 2,391,211,000,000
Financial assets held for trading (IAS 39)					3,115,775,000,000
Financial assets at FVTPL (IAS 39)					3,115,775,000,000
Debt securities
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets designated at FVTPL (IAS 39)					9,694,000,000
Equity securities
Disclosure of financial assets at fair value through profit or loss [Line Items]
Financial assets designated at FVTPL (IAS 39)					₩ 12,596,000,000
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.

Financial assets at FVTOCI and

Financial assets at FVTOCI and AFS financial assets_Details of financial assets at FVTOCI and AFS financial assets (Details)	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)		Dec. 31, 2017KRW (₩)
Disclosure of financial assets at fair value through other comprehensive income [Line Items]
Financial assets at FVTOCI	₩ 14,644,608,000,000	[1]	$ 13,171,981,000	[1]	₩ 0
Financial assets available-for-sale	0		$ 0		15,352,950,000,000
Debt securities
Disclosure of financial assets at fair value through other comprehensive income [Line Items]
Financial assets at FVTOCI	13,688,690,000,000
Financial assets available-for-sale					13,058,988,000,000
Korean treasury and government agencies
Disclosure of financial assets at fair value through other comprehensive income [Line Items]
Financial assets at FVTOCI	2,195,526,000,000
Financial assets available-for-sale					2,330,567,000,000
Financial institutions
Disclosure of financial assets at fair value through other comprehensive income [Line Items]
Financial assets at FVTOCI	7,370,107,000,000
Financial assets available-for-sale					5,217,266,000,000
Corporates
Disclosure of financial assets at fair value through other comprehensive income [Line Items]
Financial assets at FVTOCI	1,797,635,000,000
Financial assets available-for-sale					2,725,232,000,000
Asset-backed securities
Disclosure of financial assets at fair value through other comprehensive income [Line Items]
Financial assets at FVTOCI	0
Financial assets available-for-sale					308,181,000,000
Bond denominated in foreign currencies
Disclosure of financial assets at fair value through other comprehensive income [Line Items]
Financial assets at FVTOCI	2,325,422,000,000
Financial assets available-for-sale					2,442,579,000,000
Other debt securities
Disclosure of financial assets at fair value through other comprehensive income [Line Items]
Financial assets available-for-sale					35,163,000,000
Securities loaned
Disclosure of financial assets at fair value through other comprehensive income [Line Items]
Financial assets at FVTOCI	50,139,000,000
Financial assets available-for-sale					170,256,000,000
Equity securities
Disclosure of financial assets at fair value through other comprehensive income [Line Items]
Financial assets at FVTOCI	905,779,000,000
Financial assets available-for-sale					1,411,078,000,000
Beneficiary certificates
Disclosure of financial assets at fair value through other comprehensive income [Line Items]
Financial assets at FVTOCI	₩ 0
Financial assets available-for-sale					₩ 712,628,000,000
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.

Financial assets at FVTOCI a141

Financial assets at FVTOCI and AFS financial assets_Details of equity securities designated as financial assets at FVTOCI (Details) - KRW (₩)		3 Months Ended	6 Months Ended	12 Months Ended
		Jun. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [Line Items]
Investments in equity instruments designated at fair value through other comprehensive income		₩ 905,779,000,000	₩ 905,779,000,000
Description of reason for disposing of investments in equity instruments designated at fair value through other comprehensive income			The Group disposed equity securities designated as financial assets at FVTOCI in accordance with the resolution of disposal from the creditors' council for the six months ended June 30, 2018.
Fair value of investments in equity instruments designated at fair value through other comprehensive income at date of derecognition		3,974,000,000	₩ 3,974,000,000
Cumulative gain (loss) on disposal of investments in equity instruments designated at fair value through other comprehensive income		(424,000,000)	(424,000,000)	₩ 0
Strategic business partnership
Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [Line Items]
Investments in equity instruments designated at fair value through other comprehensive income		737,104,000,000	₩ 737,104,000,000
Description of reason for using presentation alternative			Strategic business partnership
Debt-equity swap
Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [Line Items]
Investments in equity instruments designated at fair value through other comprehensive income		168,533,000,000	₩ 168,533,000,000
Description of reason for using presentation alternative			Debt-equity swap
Others
Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [Line Items]
Investments in equity instruments designated at fair value through other comprehensive income		₩ 142,000,000	₩ 142,000,000
Description of reason for using presentation alternative	[1]		Others
[1]	Cooperate insurance, etc.

Financial assets at FVTOCI a142

Financial assets at FVTOCI and AFS financial assets_Changes in loss allowance of financial assets at FVTOCI (Details) - KRW (₩)		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disclosure of reconciliation of changes in loss allowance for financial assets at fair value through other comprehensive income [Line Items]
Beginning balance	[1]			₩ (4,236,000,000)
Increase (decrease) in impairment loss financial assets at financial assets at fair value through other comprehensive income [Abstract]
Transfer to 12-month expected credit losses				0
Transfer to lifetime expected credit losses				0
Transfer to credit impaired financial assets				0
Reversal of credit loss on financial assets at financial assets at FVTOCI		₩ (679,000,000)	₩ 0	(459,000,000)	₩ 0
Disposal				27,000,000
Other increase (decrease)	[2]			(2,000,000)
Ending balance		(4,670,000,000)		(4,670,000,000)
Financial assets at fair value through other comprehensive income, category [Member] | Stage 1
Disclosure of reconciliation of changes in loss allowance for financial assets at fair value through other comprehensive income [Line Items]
Beginning balance	[1]			(4,107,000,000)
Increase (decrease) in impairment loss financial assets at financial assets at fair value through other comprehensive income [Abstract]
Transfer to 12-month expected credit losses				0
Transfer to lifetime expected credit losses				0
Transfer to credit impaired financial assets				0
Reversal of credit loss on financial assets at financial assets at FVTOCI				(562,000,000)
Disposal				27,000,000
Other increase (decrease)	[2]			(2,000,000)
Ending balance		(4,644,000,000)		(4,644,000,000)
Financial assets at fair value through other comprehensive income, category [Member] | Stage 2
Disclosure of reconciliation of changes in loss allowance for financial assets at fair value through other comprehensive income [Line Items]
Beginning balance	[1]			(129,000,000)
Increase (decrease) in impairment loss financial assets at financial assets at fair value through other comprehensive income [Abstract]
Transfer to 12-month expected credit losses				0
Transfer to lifetime expected credit losses				0
Transfer to credit impaired financial assets				0
Reversal of credit loss on financial assets at financial assets at FVTOCI				103,000,000
Disposal				0
Other increase (decrease)				0
Ending balance		(26,000,000)		(26,000,000)
Financial assets at fair value through other comprehensive income, category [Member] | Stage 3
Disclosure of reconciliation of changes in loss allowance for financial assets at fair value through other comprehensive income [Line Items]
Beginning balance	[1]			0
Increase (decrease) in impairment loss financial assets at financial assets at fair value through other comprehensive income [Abstract]
Transfer to 12-month expected credit losses				0
Transfer to lifetime expected credit losses				0
Transfer to credit impaired financial assets				0
Reversal of credit loss on financial assets at financial assets at FVTOCI				0
Disposal				0
Other increase (decrease)				0
Ending balance		₩ 0		₩ 0
[1]	The beginning balance was restated in accordance with IFRS 9.
[2]	Others consist of foreign currencies translation, etc.

Financial assets at FVTOCI a143

Financial assets at FVTOCI and AFS financial assets_Changes in gross carrying amount of financial assets at FVTOCI (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)
Explanation of changes in gross carrying amount for financial assets at fair value through other comprehensive income [Line Items]
Beginning balance	₩ 12,874,209,000,000
Increase (decrease) in financial assets [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit impaired financial assets	0
Acquisition	5,075,597,000,000
Disposal and Redemption	(4,309,182,000,000)
Gain (loss) on valuation	12,884,000,000
Amortization on the effective interest method	(2,289,000,000)
Other increase (decrease)	87,610,000,000	[1]
Ending balance	13,738,829,000,000
Financial assets at fair value through other comprehensive income, category [Member] | Stage 1
Explanation of changes in gross carrying amount for financial assets at fair value through other comprehensive income [Line Items]
Beginning balance	12,843,997,000,000
Increase (decrease) in financial assets [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit impaired financial assets	0
Acquisition	5,075,597,000,000
Disposal and Redemption	(4,294,135,000,000)
Gain (loss) on valuation	12,874,000,000
Amortization on the effective interest method	(2,289,000,000)
Other increase (decrease)	87,610,000,000	[1]
Ending balance	13,723,654,000,000
Financial assets at fair value through other comprehensive income, category [Member] | Stage 2
Explanation of changes in gross carrying amount for financial assets at fair value through other comprehensive income [Line Items]
Beginning balance	30,212,000,000
Increase (decrease) in financial assets [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit impaired financial assets	0
Acquisition	0
Disposal and Redemption	(15,047,000,000)
Gain (loss) on valuation	10,000,000
Amortization on the effective interest method	0
Other increase (decrease)	0
Ending balance	15,175,000,000
Financial assets at fair value through other comprehensive income, category [Member] | Stage 3
Explanation of changes in gross carrying amount for financial assets at fair value through other comprehensive income [Line Items]
Beginning balance	0
Increase (decrease) in financial assets [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit impaired financial assets	0
Acquisition	0
Disposal and Redemption	0
Gain (loss) on valuation	0
Amortization on the effective interest method	0
Other increase (decrease)	0
Ending balance	₩ 0
[1]	Others consist of foreign currencies translation, etc.

Securities at amortized cost144

Securities at amortized cost and HTM financial assets_Details of securities at amortized cost and HTM financial assets (Details)	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Disclosure of securities at amortised cost and held to maturity financial assets [Line Items]
Securities at amortized cost	₩ 17,702,129,000,000	[1]	$ 15,922,044,000	₩ 0
Held-to-maturity financial assets	0		$ 0	16,749,296,000,000
Securities at amortised cost and held to maturity investments category [Member] | Accumulated impairment losses
Disclosure of securities at amortised cost and held to maturity financial assets [Line Items]
Securities at amortized cost	(5,250,000,000)
Held-to-maturity financial assets				0
Korean treasury and government agencies
Disclosure of securities at amortised cost and held to maturity financial assets [Line Items]
Securities at amortized cost	4,630,598,000,000
Held-to-maturity financial assets				3,994,857,000,000
Financial institutions
Disclosure of securities at amortised cost and held to maturity financial assets [Line Items]
Securities at amortized cost	7,767,490,000,000
Held-to-maturity financial assets				7,245,426,000,000
Corporates
Disclosure of securities at amortised cost and held to maturity financial assets [Line Items]
Securities at amortized cost	5,074,097,000,000
Held-to-maturity financial assets				5,311,970,000,000
Bond denominated in foreign currencies
Disclosure of securities at amortised cost and held to maturity financial assets [Line Items]
Securities at amortized cost	₩ 235,194,000,000
Held-to-maturity financial assets				₩ 197,043,000,000
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.

Securities at amortized cost145

Securities at amortized cost and HTM financial assets_Changes in loss allowance of securities at amortized cost (Details) - KRW (₩)		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disclosure of reconciliation of changes in loss allowance for securities at amortised cost [Line Items]
Beginning balance	[1]			₩ (5,078,000,000)
Increase (decrease) in impairment loss securities at amortised cost [Abstract]
Transfer to 12-month expected credit losses				0
Transfer to lifetime expected credit losses				0
Transfer to credit-impaired financial assets				0
Reversal of credit loss on securities at amortized cost losses		₩ (199,000,000)	₩ 0	(191,000,000)	₩ 0
Disposal				22,000,000
Others	[2]			(3,000,000)
Ending balance		(5,250,000,000)		(5,250,000,000)
Securities at amortized cost | Stage 1
Disclosure of reconciliation of changes in loss allowance for securities at amortised cost [Line Items]
Beginning balance	[1]			(5,078,000,000)
Increase (decrease) in impairment loss securities at amortised cost [Abstract]
Transfer to 12-month expected credit losses				0
Transfer to lifetime expected credit losses				0
Transfer to credit-impaired financial assets				0
Reversal of credit loss on securities at amortized cost losses				(191,000,000)
Disposal				22,000,000
Others	[2]			(3,000,000)
Ending balance		(5,250,000,000)		(5,250,000,000)
Securities at amortized cost | Stage 2
Disclosure of reconciliation of changes in loss allowance for securities at amortised cost [Line Items]
Beginning balance	[1]			0
Increase (decrease) in impairment loss securities at amortised cost [Abstract]
Transfer to 12-month expected credit losses				0
Transfer to lifetime expected credit losses				0
Transfer to credit-impaired financial assets				0
Reversal of credit loss on securities at amortized cost losses				0
Disposal				0
Others				0
Ending balance		0		0
Securities at amortized cost | Stage 3
Disclosure of reconciliation of changes in loss allowance for securities at amortised cost [Line Items]
Beginning balance	[1]			0
Increase (decrease) in impairment loss securities at amortised cost [Abstract]
Transfer to 12-month expected credit losses				0
Transfer to lifetime expected credit losses				0
Transfer to credit-impaired financial assets				0
Reversal of credit loss on securities at amortized cost losses				0
Disposal				0
Others				0
Ending balance		₩ 0		₩ 0
[1]	The beginning balance was restated in accordance with IFRS 9.
[2]	Others consist of foreign currencies translation, etc.

Securities at amortized cost146

Securities at amortized cost and HTM financial assets_Changes in carrying amount of securities at amortized cost (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)
Explanation of changes in gross carrying amount for securities at amortised cost [Line Items]
Beginning balance	₩ 16,749,296,000,000
Increase (decrease) in impairment loss securities at amortised cost [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit impaired financial assets	0
Acquisition	5,829,462,000,000
Disposal and Redemption	(4,873,896,000,000)
Amortization on the effective interest method	(6,008,000,000)
Other increase (decrease)	8,525,000,000	[1]
Ending balance	17,707,379,000,000
Securities at amortized cost | Stage 1
Explanation of changes in gross carrying amount for securities at amortised cost [Line Items]
Beginning balance	16,749,296,000,000
Increase (decrease) in impairment loss securities at amortised cost [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit impaired financial assets	0
Acquisition	5,829,462,000,000
Disposal and Redemption	(4,873,896,000,000)
Amortization on the effective interest method	(6,008,000,000)
Other increase (decrease)	8,525,000,000	[1]
Ending balance	17,707,379,000,000
Securities at amortized cost | Stage 2
Explanation of changes in gross carrying amount for securities at amortised cost [Line Items]
Beginning balance	0
Increase (decrease) in impairment loss securities at amortised cost [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit impaired financial assets	0
Acquisition	0
Disposal and Redemption	0
Amortization on the effective interest method	0
Other increase (decrease)	0
Ending balance	0
Securities at amortized cost | Stage 3
Explanation of changes in gross carrying amount for securities at amortised cost [Line Items]
Beginning balance	0
Increase (decrease) in impairment loss securities at amortised cost [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit impaired financial assets	0
Acquisition	0
Disposal and Redemption	0
Amortization on the effective interest method	0
Other increase (decrease)	0
Ending balance	₩ 0
[1]	Others consist of foreign currencies translation, etc.

Loans and other financial as147

Loans and other financial assets at amortized cost, and loans and receivables_Details of loans and other financial assets at amortized cost, and loans and receivables (Details)	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Disclosure of loans and other financial assets at amortised cost and loans and receivables [Abstract]
Due from banks	₩ 17,770,356,000,000			₩ 8,868,378,000,000
Loans	248,794,014,000,000			251,523,301,000,000
Other financial assets (other receivables)	11,155,633,000,000			6,714,525,000,000
Total	0		$ 0	267,106,204,000,000
Total	₩ 277,720,003,000,000	[1]	$ 249,793,131,000	₩ 0
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.

Loans and other financial as148

Loans and other financial assets at amortized cost, and loans and receivables_Details of due from banks (Details) - KRW (₩)	Jun. 30, 2018	Dec. 31, 2017
Cashand cash equivalents [Line Items]
Total	₩ 17,770,356,000,000	₩ 8,868,378,000,000
Due from banks in local currency
Cashand cash equivalents [Line Items]
Total	14,655,439,000,000	6,422,473,000,000
Due from banks in local currency | Loss allowance
Cashand cash equivalents [Line Items]
Total	(3,475,000,000)	(1,541,000,000)
Due from banks in local currency | Due from the Bank of Korea | Gross carrying amount [Member]
Cashand cash equivalents [Line Items]
Total	14,500,746,000,000	6,246,496,000,000
Due from banks in local currency | Due from the depository banks | Gross carrying amount [Member]
Cashand cash equivalents [Line Items]
Total	90,003,000,000	30,003,000,000
Due from banks in local currency | Due from non-monetary financial institutions | Gross carrying amount [Member]
Cashand cash equivalents [Line Items]
Total	33,000,000	150,000,000
Due from banks in local currency | Due from the Korea Exchange | Gross carrying amount [Member]
Cashand cash equivalents [Line Items]
Total	0	50,000,000,000
Due from banks in local currency | Others | Gross carrying amount [Member]
Cashand cash equivalents [Line Items]
Total	68,132,000,000	97,365,000,000
Due from banks in foreign currencies
Cashand cash equivalents [Line Items]
Total	3,114,917,000,000	2,445,905,000,000
Due from banks in foreign currencies | Loss allowance
Cashand cash equivalents [Line Items]
Total	(2,137,000,000)	(917,000,000)
Due from banks in foreign currencies | Due from banks on demand | Gross carrying amount [Member]
Cashand cash equivalents [Line Items]
Total	1,055,513,000,000	794,353,000,000
Due from banks in foreign currencies | Due from banks on time | Gross carrying amount [Member]
Cashand cash equivalents [Line Items]
Total	1,237,312,000,000	972,915,000,000
Due from banks in foreign currencies | Others | Gross carrying amount [Member]
Cashand cash equivalents [Line Items]
Total	₩ 824,229,000,000	₩ 679,554,000,000

Loans and other financial as149

Loans and other financial assets at amortized cost, and loans and receivables_Details of restricted due from banks (Details) - KRW (₩) ₩ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Restricted due from financial institutions [Line Items]
Total	₩ 16,437,790	₩ 7,495,518
Due from banks in local currency
Restricted due from financial institutions [Line Items]
Total	14,564,896	6,340,890
Due from banks in local currency | Due from the Bank of Korea
Restricted due from financial institutions [Line Items]
Total	₩ 14,500,746	₩ 6,246,496
Reason of restriction	Reserve deposits under BOK Act	Reserve deposits under BOK Act
Counterparty	The BOK	The BOK
Due from banks in local currency | Others
Restricted due from financial institutions [Line Items]
Total	₩ 64,150	₩ 94,394
Reason of restriction	Central counterparty KRW margin and others	Central counterparty KRW margin and others
Counterparty	The Korea Exchange and others	The Korea Exchange and others
Due from banks in foreign currencies
Restricted due from financial institutions [Line Items]
Total	₩ 1,872,894	₩ 1,154,628
Due from banks in foreign currencies | Due from banks on demand
Restricted due from financial institutions [Line Items]
Total	₩ 824,229	₩ 787,520
Reason of restriction	Reserve deposits and others	Reserve deposits under the BOK Act and others
Counterparty	The People’s Bank of China and others	The BOK and others
Due from banks in foreign currencies | Others
Restricted due from financial institutions [Line Items]
Total	₩ 1,048,609	₩ 367,108
Reason of restriction	Reserve deposits under the BOK Act and others	Reserve deposits and others
Counterparty	The BOK and others	The People’s Bank of China and others
Due from banks in foreign currencies | Due from banks on time
Restricted due from financial institutions [Line Items]
Total	₩ 56
Reason of restriction	Fast And Secure Transfer(Payment system)
Counterparty	National Bank of Cambodia

Loans and other financial as150

Loans and other financial assets at amortized cost, and loans and receivables_Changes in loss allowance of due from banks (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)
Reconciliation of changes in loss allowance for due from financial institutions [Line Items]
Beginning balance	₩ (3,092,000,000)	[1]
Increase (decrease) in impairment loss due from financial institutions [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit impaired financial assets	0
Net provision of loss allowance	(2,500,000,000)
Others	(20,000,000)	[2]
Ending balance	(5,612,000,000)
Stage 1
Reconciliation of changes in loss allowance for due from financial institutions [Line Items]
Beginning balance	(3,092,000,000)	[1]
Increase (decrease) in impairment loss due from financial institutions [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit impaired financial assets	0
Net provision of loss allowance	(2,500,000,000)
Others	(20,000,000)	[2]
Ending balance	(5,612,000,000)
Stage 2
Reconciliation of changes in loss allowance for due from financial institutions [Line Items]
Beginning balance	0
Increase (decrease) in impairment loss due from financial institutions [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit impaired financial assets	0
Net provision of loss allowance	0
Others	0
Ending balance	0
Stage 3
Reconciliation of changes in loss allowance for due from financial institutions [Line Items]
Beginning balance	0
Increase (decrease) in impairment loss due from financial institutions [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit impaired financial assets	0
Net provision of loss allowance	0
Others	0
Ending balance	₩ 0
[1]	The beginning balance was restated in accordance with IFRS 9.
[2]	Others consist of foreign currencies translation and etc.

Loans and other financial as151

Loans and other financial assets at amortized cost, and loans and receivables_Changes in gross carrying amount of due from banks (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)
Reconciliation of changes in gross carrying amount of due from financial institutions [Line Items]
Beginning balance	₩ 8,870,835,000,000
Changes in gross carrying amount of due from financial institutions [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit-impaired financial assets	0
Net increase	8,855,041,000,000
Others	50,092,000,000	[1]
Ending balance	17,775,968,000,000
Stage 1
Reconciliation of changes in gross carrying amount of due from financial institutions [Line Items]
Beginning balance	8,870,835,000,000
Changes in gross carrying amount of due from financial institutions [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit-impaired financial assets	0
Net increase	8,855,041,000,000
Others	50,092,000,000	[1]
Ending balance	17,775,968,000,000
Stage 2
Reconciliation of changes in gross carrying amount of due from financial institutions [Line Items]
Beginning balance	0
Changes in gross carrying amount of due from financial institutions [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit-impaired financial assets	0
Net increase	0
Others	0
Ending balance	0
Stage 3
Reconciliation of changes in gross carrying amount of due from financial institutions [Line Items]
Beginning balance	0
Changes in gross carrying amount of due from financial institutions [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit-impaired financial assets	0
Net increase	0
Others	0
Ending balance	₩ 0
[1]	Others consist of foreign currencies translation and etc.

Loans and other financial as152

Loans and other financial assets at amortized cost, and loans and receivables_Details of loans (Details) - KRW (₩) ₩ in Millions	Jun. 30, 2018	Dec. 31, 2017
Disclosure of loans other than banks [Line Items]
Total	₩ 248,794,014	₩ 251,523,301
Present value discount
Disclosure of loans other than banks [Line Items]
Total	(5,068)	(10,988)
Loss allowance
Disclosure of loans other than banks [Line Items]
Total	(1,750,305)	(1,770,222)
Loans in local currency | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	204,830,133	200,213,230
Loans in foreign currencies | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	14,731,407	13,147,888
Domestic banker’s letter of credit | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	3,074,011	2,516,907
Credit card accounts | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	7,570,281	6,827,295
Bills bought in foreign currencies | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	6,830,374	8,197,159
Bills bought in local currency | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	257,405	334,714
Factoring receivables | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	61,382	137,523
Advances for customers on guarantees | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	14,910	23,620
Privately placed bonds | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	433,591	362,319
Securitized loans | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	1,228,212	563,152
Call loans | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	3,135,670	3,003,455
Bonds purchased under resale agreements | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	6,999,881	16,859,064
Loan origination costs and fees | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	545,864	510,860
Others | Gross carrying amount [Member]
Disclosure of loans other than banks [Line Items]
Total	₩ 836,266	₩ 607,325

Loans and other financial as153

Loans and other financial assets at amortized cost, and loans and receivables_Changes in loss allowance on loans (Details) - KRW (₩)		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance			₩ (2,027,096,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Net reversal of provision (net provision)			(333,976,000,000)
Recoveries of written off loans			(101,789,000,000)
Charge off			443,646,000,000
Sales of loans and receivables			88,525,000,000
Unwinding effect			24,667,000,000
Others			178,851,000,000
Ending balance			(1,727,172,000,000)
Stage 1
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance	[1]	₩ (523,859,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Transfer to 12-month expected credit losses		(43,101,000,000)
Transfer to lifetime expected credit losses		30,302,000,000
Transfer to credit-impaired financial assets		22,851,000,000
Net reversal (provision) of loss allowance		(28,912,000,000)
Recoveries of loans previously charged off		0
Charge off		0
Disposal		0
Unwinding effect		0
Others	[2]	21,920,000,000
Ending balance		(520,799,000,000)
Stage 2
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance	[1]	(368,747,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Transfer to 12-month expected credit losses		42,311,000,000
Transfer to lifetime expected credit losses		(121,784,000,000)
Transfer to credit-impaired financial assets		37,781,000,000
Net reversal (provision) of loss allowance		(10,619,000,000)
Recoveries of loans previously charged off		0
Charge off		0
Disposal		67,000,000
Unwinding effect		0
Others	[2]	(126,000,000)
Ending balance		(421,117,000,000)
Stage 3
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance	[1]	(1,125,269,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Transfer to 12-month expected credit losses		790,000,000
Transfer to lifetime expected credit losses		91,482,000,000
Transfer to credit-impaired financial assets		(60,632,000,000)
Net reversal (provision) of loss allowance		12,444,000,000
Recoveries of loans previously charged off		(104,371,000,000)
Charge off		343,553,000,000
Disposal		18,456,000,000
Unwinding effect		16,626,000,000
Others	[2]	(1,468,000,000)
Ending balance		(808,389,000,000)
Consumers
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance			(163,858,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Net reversal of provision (net provision)			(65,582,000,000)
Recoveries of written off loans			(21,659,000,000)
Charge off			67,593,000,000
Sales of loans and receivables			830,000,000
Unwinding effect			4,620,000,000
Others			416,000,000
Ending balance			(177,640,000,000)
Consumers | Stage 1
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance	[1]	(101,479,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Transfer to 12-month expected credit losses		(9,219,000,000)
Transfer to lifetime expected credit losses		6,076,000,000
Transfer to credit-impaired financial assets		19,177,000,000
Net reversal (provision) of loss allowance		(22,903,000,000)
Recoveries of loans previously charged off		0
Charge off		0
Disposal		0
Unwinding effect		0
Others	[2]	(1,994,000,000)
Ending balance		(110,342,000,000)
Consumers | Stage 2
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance	[1]	(41,358,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Transfer to 12-month expected credit losses		8,797,000,000
Transfer to lifetime expected credit losses		(7,514,000,000)
Transfer to credit-impaired financial assets		23,228,000,000
Net reversal (provision) of loss allowance		(29,025,000,000)
Recoveries of loans previously charged off		0
Charge off		0
Disposal		0
Unwinding effect		0
Others	[2]	(39,000,000)
Ending balance		(45,911,000,000)
Consumers | Stage 3
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance	[1]	(117,168,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Transfer to 12-month expected credit losses		421,000,000
Transfer to lifetime expected credit losses		1,438,000,000
Transfer to credit-impaired financial assets		(42,406,000,000)
Net reversal (provision) of loss allowance		(51,219,000,000)
Recoveries of loans previously charged off		(23,392,000,000)
Charge off		117,228,000,000
Disposal		780,000,000
Unwinding effect		3,665,000,000
Others	[2]	(1,156,000,000)
Ending balance		(111,809,000,000)
Corporates
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance			(1,498,842,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Net reversal of provision (net provision)			(191,263,000,000)
Recoveries of written off loans			(55,319,000,000)
Charge off			220,598,000,000
Sales of loans and receivables			58,431,000,000
Unwinding effect			20,047,000,000
Others			179,068,000,000
Ending balance			(1,267,280,000,000)
Corporates | Stage 1
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance	[1]	(365,246,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Transfer to 12-month expected credit losses		(20,913,000,000)
Transfer to lifetime expected credit losses		17,263,000,000
Transfer to credit-impaired financial assets		2,976,000,000
Net reversal (provision) of loss allowance		(5,600,000,000)
Recoveries of loans previously charged off		0
Charge off		0
Disposal		0
Unwinding effect		0
Others	[2]	23,916,000,000
Ending balance		(347,604,000,000)
Corporates | Stage 2
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance	[1]	(255,926,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Transfer to 12-month expected credit losses		20,634,000,000
Transfer to lifetime expected credit losses		(106,963,000,000)
Transfer to credit-impaired financial assets		12,016,000,000
Net reversal (provision) of loss allowance		30,121,000,000
Recoveries of loans previously charged off		0
Charge off		0
Disposal		67,000,000
Unwinding effect		0
Others	[2]	(87,000,000)
Ending balance		(300,138,000,000)
Corporates | Stage 3
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance	[1]	(905,243,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Transfer to 12-month expected credit losses		280,000,000
Transfer to lifetime expected credit losses		89,700,000,000
Transfer to credit-impaired financial assets		(14,991,000,000)
Net reversal (provision) of loss allowance		154,111,000,000
Recoveries of loans previously charged off		(52,273,000,000)
Charge off		121,847,000,000
Disposal		17,676,000,000
Unwinding effect		12,961,000,000
Others	[2]	(312,000,000)
Ending balance		(576,244,000,000)
Credit card
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance			(155,372,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Net reversal of provision (net provision)			(91,022,000,000)
Recoveries of written off loans			(24,808,000,000)
Charge off			104,195,000,000
Sales of loans and receivables			0
Unwinding effect			0
Others			0
Ending balance			(167,007,000,000)
Credit card | Stage 1
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance	[1]	(57,134,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Transfer to 12-month expected credit losses		(12,969,000,000)
Transfer to lifetime expected credit losses		6,963,000,000
Transfer to credit-impaired financial assets		698,000,000
Net reversal (provision) of loss allowance		(409,000,000)
Recoveries of loans previously charged off		0
Charge off		0
Disposal		0
Unwinding effect		0
Others	[2]	(2,000,000)
Ending balance		(62,853,000,000)
Credit card | Stage 2
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance	[1]	(71,463,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Transfer to 12-month expected credit losses		12,880,000,000
Transfer to lifetime expected credit losses		(7,307,000,000)
Transfer to credit-impaired financial assets		2,537,000,000
Net reversal (provision) of loss allowance		(11,715,000,000)
Recoveries of loans previously charged off		0
Charge off		0
Disposal		0
Unwinding effect		0
Others		0
Ending balance		(75,068,000,000)
Credit card | Stage 3
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance	[1]	(102,858,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Transfer to 12-month expected credit losses		89,000,000
Transfer to lifetime expected credit losses		344,000,000
Transfer to credit-impaired financial assets		(3,235,000,000)
Net reversal (provision) of loss allowance		(90,448,000,000)
Recoveries of loans previously charged off		(28,706,000,000)
Charge off		104,478,000,000
Disposal		0
Unwinding effect		0
Others		0
Ending balance		₩ (120,336,000,000)
Others
Reconciliation of changes in allowance account for credit losses of financial assets [Line Items]
Beginning balance			(209,024,000,000)
Changes in allowance account for credit losses of financial assets [Abstract]
Net reversal of provision (net provision)			13,891,000,000
Recoveries of written off loans			(3,000,000)
Charge off			51,260,000,000
Sales of loans and receivables			29,264,000,000
Unwinding effect			0
Others			(633,000,000)
Ending balance			₩ (115,245,000,000)
[1]	The beginning balance was restated in accordance with IFRS 9.
[2]	Others consist of debt-equity swap, foreign currencies translation and etc.

Loans and other financial as154

Loans and other financial assets at amortized cost, and loans and receivables_Changes in gross carrying amount of loans (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)
Stage 1
Reconciliation of changes in gross carrying amount of loans [Line Items]
Beginning balance	₩ 239,785,876,000,000
Changes in gross carrying amount of loans [Abstract]
Transfer to 12-month expected credit losses	3,129,883,000,000
Transfer to lifetime expected credit losses	(5,144,000,000,000)
Transfer to credit-impaired financial assets	(268,106,000,000)
Charge off	0
Disposal	0
Net increase (decrease)	(884,279,000,000)
Ending balance	236,619,374,000,000
Stage 2
Reconciliation of changes in gross carrying amount of loans [Line Items]
Beginning balance	11,423,990,000,000
Changes in gross carrying amount of loans [Abstract]
Transfer to 12-month expected credit losses	(3,124,443,000,000)
Transfer to lifetime expected credit losses	5,269,372,000,000
Transfer to credit-impaired financial assets	(243,986,000,000)
Charge off	0
Disposal	(1,153,000,000)
Net increase (decrease)	(1,385,273,000,000)
Ending balance	11,938,507,000,000
Stage 3
Reconciliation of changes in gross carrying amount of loans [Line Items]
Beginning balance	2,127,132,000,000
Changes in gross carrying amount of loans [Abstract]
Transfer to 12-month expected credit losses	(5,440,000,000)
Transfer to lifetime expected credit losses	(125,372,000,000)
Transfer to credit-impaired financial assets	512,092,000,000
Charge off	(343,553,000,000)
Disposal	(81,178,000,000)
Net increase (decrease)	(97,243,000,000)
Ending balance	1,986,438,000,000
Consumers | Stage 1
Reconciliation of changes in gross carrying amount of loans [Line Items]
Beginning balance	103,502,347,000,000
Changes in gross carrying amount of loans [Abstract]
Transfer to 12-month expected credit losses	1,772,982,000,000
Transfer to lifetime expected credit losses	(2,731,516,000,000)
Transfer to credit-impaired financial assets	(84,885,000,000)
Charge off	0
Disposal	0
Net increase (decrease)	2,913,765,000,000
Ending balance	105,372,693,000,000
Consumers | Stage 2
Reconciliation of changes in gross carrying amount of loans [Line Items]
Beginning balance	5,487,758,000,000
Changes in gross carrying amount of loans [Abstract]
Transfer to 12-month expected credit losses	(1,768,978,000,000)
Transfer to lifetime expected credit losses	2,746,818,000,000
Transfer to credit-impaired financial assets	(101,151,000,000)
Charge off	0
Disposal	(270,000,000)
Net increase (decrease)	(742,949,000,000)
Ending balance	5,621,228,000,000
Consumers | Stage 3
Reconciliation of changes in gross carrying amount of loans [Line Items]
Beginning balance	326,739,000,000
Changes in gross carrying amount of loans [Abstract]
Transfer to 12-month expected credit losses	(4,004,000,000)
Transfer to lifetime expected credit losses	(15,302,000,000)
Transfer to credit-impaired financial assets	186,036,000,000
Charge off	(117,228,000,000)
Disposal	(13,483,000,000)
Net increase (decrease)	(22,980,000,000)
Ending balance	339,778,000,000
Corporates | Stage 1
Reconciliation of changes in gross carrying amount of loans [Line Items]
Beginning balance	130,561,786,000,000
Changes in gross carrying amount of loans [Abstract]
Transfer to 12-month expected credit losses	1,113,857,000,000
Transfer to lifetime expected credit losses	(2,112,755,000,000)
Transfer to credit-impaired financial assets	(155,933,000,000)
Charge off	0
Disposal	0
Net increase (decrease)	(4,520,684,000,000)
Ending balance	124,886,271,000,000
Corporates | Stage 2
Reconciliation of changes in gross carrying amount of loans [Line Items]
Beginning balance	5,000,966,000,000
Changes in gross carrying amount of loans [Abstract]
Transfer to 12-month expected credit losses	(1,112,533,000,000)
Transfer to lifetime expected credit losses	2,222,364,000,000
Transfer to credit-impaired financial assets	(118,707,000,000)
Charge off	0
Disposal	(883,000,000)
Net increase (decrease)	(688,875,000,000)
Ending balance	5,302,332,000,000
Corporates | Stage 3
Reconciliation of changes in gross carrying amount of loans [Line Items]
Beginning balance	1,622,410,000,000
Changes in gross carrying amount of loans [Abstract]
Transfer to 12-month expected credit losses	(1,324,000,000)
Transfer to lifetime expected credit losses	(109,609,000,000)
Transfer to credit-impaired financial assets	274,640,000,000
Charge off	(121,847,000,000)
Disposal	(67,695,000,000)
Net increase (decrease)	(149,456,000,000)
Ending balance	1,447,119,000,000
Credit card | Stage 1
Reconciliation of changes in gross carrying amount of loans [Line Items]
Beginning balance	5,721,743,000,000
Changes in gross carrying amount of loans [Abstract]
Transfer to 12-month expected credit losses	243,044,000,000
Transfer to lifetime expected credit losses	(299,729,000,000)
Transfer to credit-impaired financial assets	(27,288,000,000)
Charge off	0
Disposal	0
Net increase (decrease)	722,640,000,000
Ending balance	6,360,410,000,000
Credit card | Stage 2
Reconciliation of changes in gross carrying amount of loans [Line Items]
Beginning balance	935,266,000,000
Changes in gross carrying amount of loans [Abstract]
Transfer to 12-month expected credit losses	(242,932,000,000)
Transfer to lifetime expected credit losses	300,190,000,000
Transfer to credit-impaired financial assets	(24,128,000,000)
Charge off	0
Disposal	0
Net increase (decrease)	46,551,000,000
Ending balance	1,014,947,000,000
Credit card | Stage 3
Reconciliation of changes in gross carrying amount of loans [Line Items]
Beginning balance	177,983,000,000
Changes in gross carrying amount of loans [Abstract]
Transfer to 12-month expected credit losses	(112,000,000)
Transfer to lifetime expected credit losses	(461,000,000)
Transfer to credit-impaired financial assets	51,416,000,000
Charge off	(104,478,000,000)
Disposal	0
Net increase (decrease)	75,193,000,000
Ending balance	₩ 199,541,000,000

Loans and other financial as155

Loans and other financial assets at amortized cost, and loans and receivables_Details of other financial assests other receivables (Details) - KRW (₩) ₩ in Millions	Jun. 30, 2018	Dec. 31, 2017
Disclosure of other financial assets [Line Items]
Other receivables	₩ 11,155,633	₩ 6,714,525
Loss allowance
Disclosure of other financial assets [Line Items]
Other receivables	(74,839)	(57,563)
CMA accounts | Gross carrying amount [Member]
Disclosure of other financial assets [Line Items]
Other receivables	200,000	135,000
Receivables | Gross carrying amount [Member]
Disclosure of other financial assets [Line Items]
Other receivables	8,721,745	4,459,318
Accrued income | Gross carrying amount [Member]
Disclosure of other financial assets [Line Items]
Other receivables	1,055,713	1,026,273
Telex and telephone subscription rights and refundable deposits | Gross carrying amount [Member]
Disclosure of other financial assets [Line Items]
Other receivables	980,611	984,620
Other receivables | Gross carrying amount [Member]
Disclosure of other financial assets [Line Items]
Other receivables	₩ 272,403	₩ 166,877

Loans and other financial as156

Loans and other financial assets at amortized cost, and loans and receivables_Changes in loss allowance on other financial assets (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)
Reconciliation of changes in allowance account for credit losses of other receivables [Line Items]
Beginning balance	₩ (58,998,000,000)	[1]
Changes in allowance account for credit losses of other receivables [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit-impaired financial assets	0
Net provision of loss allowance	(31,470,000,000)
Recoveries of other financial assets previously	(2,000,000)
Charge off	15,225,000,000
Disposal	593,000,000
Others	(187,000,000)
Ending balance	(74,839,000,000)
Stage 1
Reconciliation of changes in allowance account for credit losses of other receivables [Line Items]
Beginning balance	(2,955,000,000)	[1]
Changes in allowance account for credit losses of other receivables [Abstract]
Transfer to 12-month expected credit losses	(161,000,000)
Transfer to lifetime expected credit losses	112,000,000
Transfer to credit-impaired financial assets	23,000,000
Net provision of loss allowance	(360,000,000)
Recoveries of other financial assets previously	0
Charge off	0
Disposal	0
Others	(208,000,000)
Ending balance	(3,549,000,000)
Stage 2
Reconciliation of changes in allowance account for credit losses of other receivables [Line Items]
Beginning balance	(1,832,000,000)	[1]
Changes in allowance account for credit losses of other receivables [Abstract]
Transfer to 12-month expected credit losses	146,000,000
Transfer to lifetime expected credit losses	(122,000,000)
Transfer to credit-impaired financial assets	167,000,000
Net provision of loss allowance	(256,000,000)
Recoveries of other financial assets previously	0
Charge off	0
Disposal	0
Others	0
Ending balance	(1,897,000,000)
Stage 3
Reconciliation of changes in allowance account for credit losses of other receivables [Line Items]
Beginning balance	(54,211,000,000)	[1]
Changes in allowance account for credit losses of other receivables [Abstract]
Transfer to 12-month expected credit losses	15,000,000
Transfer to lifetime expected credit losses	10,000,000
Transfer to credit-impaired financial assets	(190,000,000)
Net provision of loss allowance	(30,854,000,000)
Recoveries of other financial assets previously	(2,000,000)
Charge off	15,225,000,000
Disposal	593,000,000
Others	21,000,000
Ending balance	₩ (69,393,000,000)
[1]	The beginning balance was restated in accordance with IFRS 9.

Loans and other financial as157

Loans and other financial assets at amortized cost, and loans and receivables_Changes in gross carrying amount of other financial assets (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)
Reconciliation of changes in gross carrying amount of other receivables [Line Items]
Beginning balance	₩ 6,771,371,000,000
Changes in gross carrying amount of other receivables [Abstract]
Transfer to 12-month expected credit losses	0
Transfer to lifetime expected credit losses	0
Transfer to credit-impaired financial assets	0
Charge off	(15,225,000,000)
Disposal	(737,000,000)
Net increase	4,475,063,000,000
Ending balance	11,230,472,000,000
Stage 1
Reconciliation of changes in gross carrying amount of other receivables [Line Items]
Beginning balance	6,662,335,000,000
Changes in gross carrying amount of other receivables [Abstract]
Transfer to 12-month expected credit losses	8,130,000,000
Transfer to lifetime expected credit losses	(10,935,000,000)
Transfer to credit-impaired financial assets	(768,000,000)
Charge off	0
Disposal	0
Net increase	4,460,291,000,000
Ending balance	11,119,053,000,000
Stage 2
Reconciliation of changes in gross carrying amount of other receivables [Line Items]
Beginning balance	29,124,000,000
Changes in gross carrying amount of other receivables [Abstract]
Transfer to 12-month expected credit losses	(8,109,000,000)
Transfer to lifetime expected credit losses	10,949,000,000
Transfer to credit-impaired financial assets	(1,120,000,000)
Charge off	0
Disposal	(2,000,000)
Net increase	(1,650,000,000)
Ending balance	29,192,000,000
Stage 3
Reconciliation of changes in gross carrying amount of other receivables [Line Items]
Beginning balance	79,912,000,000
Changes in gross carrying amount of other receivables [Abstract]
Transfer to 12-month expected credit losses	(21,000,000)
Transfer to lifetime expected credit losses	(14,000,000)
Transfer to credit-impaired financial assets	1,888,000,000
Charge off	(15,225,000,000)
Disposal	(735,000,000)
Net increase	16,422,000,000
Ending balance	₩ 82,227,000,000

Fair value of financial asse158

Fair value of financial assets and liabilities_Fair value hierarchy of financial assets and liabilities measured at fair value (Details)		6 Months Ended		12 Months Ended
		Jun. 30, 2018KRW (₩)		Dec. 31, 2017KRW (₩)	Jun. 30, 2018USD ($)		Jun. 30, 2017KRW (₩)
Fair value of financial instruments measured at fair value [Line Items]
Description of level of fair value hierarchy within which fair value measurement is categorised		The fair value hierarchy is determined by the levels of judgment involved in estimating fair values of financial assets and liabilities. The specific financial instruments characteristics and market condition such as volume of transactions and transparency are reflected to the market observable inputs. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities. The Group maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value of its financial assets and financial liabilities. Fair value is measured based on the perspective of a market participant. As such, even when market assumptions are not readily available, the Group’s own assumptions reflect those that market participants would use for measuring the assets or liabilities at the measurement date. The fair value measurement is described in the one of the following three levels used to classify fair value measurements: •Level 1—fair value measurements are those derived from quoted prices (unadjusted) in active markets for identical assets or liabilities. The types of financial assets or liabilities generally included in Level 1 are publicly traded equity securities, derivatives, and debt securities issued by governmental bodies. •Level 2— fair value measurements are those derived from inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly (i.e. prices) or indirectly (i.e. derived from prices). The types of financial assets or liabilities generally included in Level 2 are debt securities not traded in active markets and derivatives traded in OTC but not required significant judgment. •Level 3— fair value measurements are those derived from valuation technique that include inputs for the asset or liability that are not based on observable market data (unobservable inputs). The types of financial assets or liabilities generally included in Level 3 are non-public securities and derivatives and debt securities of which valuation techniques require significant judgments and subjectivity.		The fair value hierarchy is determined by the levels of judgment involved in estimating fair values of financial assets and liabilities. The specific financial instruments characteristics and market condition such as volume of transactions and transparency are reflected to the market observable inputs. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities. The Group maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value of its financial assets and financial liabilities. Fair value is measured based on the perspective of a market participant. As such, even when market assumptions are not readily available, the Group’s own assumptions reflect those that market participants would use for measuring the assets or liabilities at the measurement date. The fair value measurement is described in the one of the following three levels used to classify fair value measurements: •Level 1—fair value measurements are those derived from quoted prices (unadjusted) in active markets for identical assets or liabilities. The types of financial assets or liabilities generally included in Level 1 are publicly traded equity securities, derivatives, and debt securities issued by governmental bodies. •Level 2— fair value measurements are those derived from inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly (i.e. prices) or indirectly (i.e. derived from prices). The types of financial assets or liabilities generally included in Level 2 are debt securities not traded in active markets and derivatives traded in OTC but not required significant judgment. •Level 3— fair value measurements are those derived from valuation technique that include inputs for the asset or liability that are not based on observable market data (unobservable inputs). The types of financial assets or liabilities generally included in Level 3 are non-public securities and derivatives and debt securities of which valuation techniques require significant judgments and subjectivity.
Financial assets held for trading (IAS 39)		₩ 0		₩ 5,820,787,000,000
Financial assets designated at FVTPL (IAS 39)		0		22,290,000,000
AFS financial assets		0		15,352,950,000,000	$ 0
Financial assets at FVTPL		6,340,704,000,000	[1]	0	5,703,098,000	[1]
Financial assets at FVTOCI		14,644,608,000,000	[1]	0	13,171,981,000	[1]
Derivative financial assets		12,395,000,000		59,272,000,000	11,149,000
Total		20,997,707,000,000		21,255,299,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at FVTPL		2,402,235,000,000		0
Carrying amount		176,097,000,000		0			₩ 0
Financial liabilities at FVTPL		2,578,332,000,000	[1]	0	2,319,061,000	[1]
Financial liabilities held for trading		0		3,176,113,000,000
Carrying amount Financial liabilities designated as at FVTPL (IAS39)		0		251,796,000,000			₩ 616,177,000,000
Derivative financial liabilities		67,505,000,000		67,754,000,000	$ 60,717,000
Total		₩ 2,645,837,000,000		₩ 3,495,663,000,000
Description of valuation processes used in fair value measurement assets		Financial assets and liabilities at fair value through profit or loss mandatorily measured at fair value, financial liabilities at fair value through profit or loss designated as upon initial recognition, financial assets at FVTOCI, and derivative assets and liabilities are recognized at fair value. Fair value is the amount that would be received to sell an asset, or paid to transfer a liability, in an orderly transaction between market participants at the measurement date. Financial instruments are measured at fair value using a quoted market price in active markets. If there is no active market for a financial instrument, the Group determines the fair value using valuation methods.		Financial assets and liabilities at fair value through profit or loss mandatorily measured at fair value, financial liabilities at fair value through profit or loss designated as upon initial recognition, financial assets at FVTOCI, and derivative assets and liabilities are recognized at fair value. Fair value is the amount that would be received to sell an asset, or paid to transfer a liability, in an orderly transaction between market participants at the measurement date. Financial instruments are measured at fair value using a quoted market price in active markets. If there is no active market for a financial instrument, the Group determines the fair value using valuation methods.
Description of valuation processes used in fair value measurement liabilities		Financial assets and liabilities at fair value through profit or loss mandatorily measured at fair value, financial liabilities at fair value through profit or loss designated as upon initial recognition, financial assets at FVTOCI, and derivative assets and liabilities are recognized at fair value. Fair value is the amount that would be received to sell an asset, or paid to transfer a liability, in an orderly transaction between market participants at the measurement date. Financial instruments are measured at fair value using a quoted market price in active markets. If there is no active market for a financial instrument, the Group determines the fair value using valuation methods.		Financial assets and liabilities at fair value through profit or loss mandatorily measured at fair value, financial liabilities at fair value through profit or loss designated as upon initial recognition, financial assets at FVTOCI, and derivative assets and liabilities are recognized at fair value. Fair value is the amount that would be received to sell an asset, or paid to transfer a liability, in an orderly transaction between market participants at the measurement date. Financial instruments are measured at fair value using a quoted market price in active markets. If there is no active market for a financial instrument, the Group determines the fair value using valuation methods.
Input variables		The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The Group’s assessment of the significance of a particular input to a fair value measurement in its entirety requires judgment and consideration of inherent factors of the asset or liability.		The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The Group’s assessment of the significance of a particular input to a fair value measurement in its entirety requires judgment and consideration of inherent factors of the asset or liability.
Input variables		The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The Group’s assessment of the significance of a particular input to a fair value measurement in its entirety requires judgment and consideration of inherent factors of the asset or liability.		The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The Group’s assessment of the significance of a particular input to a fair value measurement in its entirety requires judgment and consideration of inherent factors of the asset or liability.
Financial assets | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Total		₩ 3,402,206,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Financial assets | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Total		15,383,135,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Financial assets | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Total		2,212,366,000,000
Financial assets held for trading | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				₩ 454,601,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Financial assets held for trading | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				5,344,704,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Financial assets held for trading | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				21,482,000,000
Deposits
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				25,972,000,000
Deposits | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				25,972,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Deposits | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Deposits | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				0
Debt securities
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				₩ 2,644,333,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods				The fair value is measured by discounting the projected cash flows of debt securities by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the issuers of the securities.
Input variables				Risk-free market rate, credit spread
Debt securities | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				₩ 405,942,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Debt securities | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				2,238,391,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Debt securities | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				0
Equity securities
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				₩ 21,666,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods				Among DCF (Discounted Cash Flow) Model, FCFE (Free Cash Flow to Equity) Model, Comparable Company Analysis, Dividend Discount Model, Risk-adjusted Rate of Return Method, and Net Asset Value Method, more than one method is used given the characteristic of the subject of fair value measurement.
Input variables				Risk-free market rate, market risk premium, Beta, etc.
Equity securities | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				₩ 21,666,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Equity securities | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Equity securities | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				0
Beneficiary certificates
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				₩ 13,041,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods				Among DCF (Discounted Cash Flow) Model, FCFE (Free Cash Flow to Equity) Model, Comparable Company Analysis, Dividend Discount Model, Risk-adjusted Rate of Return Method, and Net Asset Value Method, more than one method is used given the characteristic of the subject of fair value measurement.
Input variables				Risk-free market rate, market risk premium, Beta, etc.
Beneficiary certificates | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				₩ 0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Beneficiary certificates | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				13,041,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Beneficiary certificates | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				0
Derivative assets
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				₩ 3,115,775,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods				The in-house developed model which is based on the models that are used by market participants in the valuation of general OTC derivative products, such as options, interest rate swaps, currency swap and currency forward that are based on inputs observable in the market. However, for some complicated financial instruments of which valuation should be based on some assumptions since some significant or all inputs to be used in the model are not observable in the market, the in-house derived model which is developed from the general valuation models, such as Finite Difference Method (“FDM”) or Monte Carlo Simulation.
Input variables				Risk-free market rate, forward rate, volatility, foreign exchange rate, stock prices, etc.
Derivative assets | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				₩ 1,021,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Derivative assets | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				3,093,272,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Derivative assets | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets held for trading (IAS 39)				21,482,000,000
Financial assets designated at FVTPL | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets designated at FVTPL (IAS 39)				0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Financial assets designated at FVTPL | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets designated at FVTPL (IAS 39)				0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Financial assets designated at FVTPL | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets designated at FVTPL (IAS 39)				22,290,000,000
Debt securities
Fair value of financial instruments measured at fair value [Line Items]
Financial assets designated at FVTPL (IAS 39)				₩ 9,694,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods				The fair value is measured by discounting the projected cash flows of debt securities by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the issuers of the securities.
Input variables				Risk-free market rate, credit spread
Debt securities | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets designated at FVTPL (IAS 39)				₩ 0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Debt securities | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets designated at FVTPL (IAS 39)				0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Debt securities | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets designated at FVTPL (IAS 39)				9,694,000,000
Equity securities
Fair value of financial instruments measured at fair value [Line Items]
Financial assets designated at FVTPL (IAS 39)				₩ 12,596,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods				Among DCF (Discounted Cash Flow) Model, FCFE (Free Cash Flow to Equity) Model, Comparable Company Analysis, Dividend Discount Model, Risk-adjusted Rate of Return Method, and Net Asset Value Method, more than one method is used given the characteristic of the subject of fair value measurement.
Input variables				Risk-free market rate, market risk premium, Beta, etc.
Equity securities | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets designated at FVTPL (IAS 39)				₩ 0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Equity securities | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets designated at FVTPL (IAS 39)				0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Equity securities | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets designated at FVTPL (IAS 39)				12,596,000,000
AFS financial assets | Level 1
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				3,179,164,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
AFS financial assets | Level 2
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				10,518,016,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
AFS financial assets | Level 3
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				₩ 1,655,770,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Description of financial instruments measured at cost	[3]			These unquoted equity instruments mostly represent minority investments in special purpose entity vehicles such as asset securitization structures They are measured at cost because observable inputs of financial information to measure fair value was not available to obtain or there is a significant variance in likely estimated cash flows or the probabilities for the various estimated cash flows could not be measured reliably In addition there were no indicators of impairments in these investments and the Group has no intention to dispose these investments in the foreseeable future
Equity securities of financial assets available-for-sale measured at cost	[3]			₩ 37,092,000,000
Debt securities
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				₩ 13,058,988,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods				The fair value is measured by discounting the projected cash flows of debt securities by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the issuers of the securities.
Input variables				Risk-free market rate, credit spread
Debt securities | Level 1
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				₩ 2,710,172,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Debt securities | Level 2
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				10,348,816,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Debt securities | Level 3
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				0
Equity securities
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				₩ 1,411,078,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods				Among DCF (Discounted Cash Flow) Model, FCFE (Free Cash Flow to Equity) Model, Comparable Company Analysis, Dividend Discount Model, Risk-adjusted Rate of Return Method, and Net Asset Value Method, more than one method is used given the characteristic of the subject of fair value measurement.
Input variables				Risk-free market rate, market risk premium, Beta, etc.
Equity securities | Level 1
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				₩ 399,214,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Equity securities | Level 2
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Equity securities | Level 3
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				1,011,864,000,000
Beneficiary certificates
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				₩ 712,628,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods				Among DCF (Discounted Cash Flow) Model, FCFE (Free Cash Flow to Equity) Model, Comparable Company Analysis, Dividend Discount Model, Risk-adjusted Rate of Return Method, and Net Asset Value Method, more than one method is used given the characteristic of the subject of fair value measurement.
Input variables				Risk-free market rate, market risk premium, Beta, etc.
Beneficiary certificates | Level 1
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				₩ 0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Beneficiary certificates | Level 2
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				68,722,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Beneficiary certificates | Level 3
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				643,906,000,000
Securities loaned
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				170,256,000,000
Securities loaned | Level 1
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				69,778,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Securities loaned | Level 2
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				100,478,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]			0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]			0
Securities loaned | Level 3
Fair value of financial instruments measured at fair value [Line Items]
AFS financial assets				0
Financial assets at FVTPL (IFRS 9) | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		498,176,000,000
Total				3,633,765,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0		0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0		0
Financial assets at FVTPL (IFRS 9) | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		4,095,903,000,000
Total				15,921,992,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0		0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0		0
Financial assets at FVTPL (IFRS 9) | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		1,746,625,000,000
Total				₩ 1,699,542,000,000
Deposits
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		24,921,000,000
Deposits | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		24,921,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Deposits | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Deposits | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		0
Debt securities
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		₩ 1,993,851,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods		The fair value is measured by discounting the projected cash flows of debt securities by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the issuers of the securities.
Input variables		Risk-free market rate, credit spread
Debt securities | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		₩ 375,280,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Debt securities | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		1,611,129,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Debt securities | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		7,442,000,000
Equity securities
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		₩ 433,316,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods		Among DCF (Discounted Cash Flow) Model, FCFE (Free Cash Flow to Equity) Model, Comparable Company Analysis, Dividend Discount Model, Risk-adjusted Rate of Return Method, and Net Asset Value Method, more than one method is used given the characteristic of the subject of fair value measurement.
Input variables		Risk-free market rate, market risk premium, Beta, etc.
Equity securities | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		₩ 80,536,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Equity securities | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Equity securities | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		352,780,000,000
Capital contributions
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		349,470,000,000
Capital contributions | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Capital contributions | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Capital contributions | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		349,470,000,000
Beneficiary certificates
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		₩ 810,968,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods		Among DCF (Discounted Cash Flow) Model, FCFE (Free Cash Flow to Equity) Model, Comparable Company Analysis, Dividend Discount Model, Risk-adjusted Rate of Return Method, and Net Asset Value Method, more than one method is used given the characteristic of the subject of fair value measurement.
Input variables		Risk-free market rate, market risk premium, Beta, etc.
Beneficiary certificates | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		₩ 0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Beneficiary certificates | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		62,173,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Beneficiary certificates | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		748,795,000,000
Loans
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		₩ 336,967,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods		The fair value of Loans is measured by the Binomial tree given the values of underlying assets and volatility.
Input variables		Values of underlying assets, Volatility
Loans | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		₩ 0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Loans | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		85,000,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Loans | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		251,967,000,000
Derivative instrument assets
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		₩ 2,391,211,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods		The in-house developed model which is based on the models that are used by market participants in the valuation of general OTC derivative products, such as options, interest rate swaps, currency swap and currency forward that are based on inputs observable in the market. However, for some complicated financial instruments of which valuation should be based on some assumptions since some significant or all inputs to be used in the model are not observable in the market, the in-house derived model which is developed from the general valuation models, such as Finite Difference Method (“FDM”) or Monte Carlo Simulation.
Input variables		Risk-free market rate, forward rate, volatility, foreign exchange rate, stock prices, etc.
Derivative instrument assets | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		₩ 17,439,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Derivative instrument assets | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		2,337,601,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Derivative instrument assets | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTPL		36,171,000,000
Financial assets at FVTOCI | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		2,904,030,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Financial assets at FVTOCI | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		11,274,837,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Financial assets at FVTOCI | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		465,741,000,000
Debt securities
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		₩ 13,688,690,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods		The fair value is measured by discounting the projected cash flows of debt securities by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the issuers of the securities.
Input variables		Risk-free market rate, credit spread
Debt securities | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		₩ 2,463,992,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Debt securities | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		11,224,698,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Debt securities | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		0
Equity securities
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		₩ 905,779,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods		Among DCF (Discounted Cash Flow) Model, FCFE (Free Cash Flow to Equity) Model, Comparable Company Analysis, Dividend Discount Model, Risk-adjusted Rate of Return Method, and Net Asset Value Method, more than one method is used given the characteristic of the subject of fair value measurement.
Input variables		Risk-free market rate, market risk premium, Beta, etc.
Equity securities | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		₩ 440,038,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Equity securities | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Equity securities | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		465,741,000,000
Loaned securities
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		50,139,000,000
Loaned securities | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Loaned securities | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		50,139,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0
Loaned securities | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Financial assets at FVTOCI		₩ 0
Derivative assets
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods		The in-house developed model which is based on the models that are used by market participants in the valuation of general OTC derivative products, such as options, interest rate swaps, currency swap and currency forward that are based on inputs observable in the market. However, for some complicated financial instruments of which valuation should be based on some assumptions since some significant or all inputs to be used in the model are not observable in the market, the in-house derived model which is developed from the general valuation models, such as Finite Difference Method (“FDM”) or Monte Carlo Simulation.		The in-house developed model which is based on the models that are used by market participants in the valuation of general OTC derivative products, such as options, interest rate swaps, currency swap and currency forward that are based on inputs observable in the market. However, for some complicated financial instruments of which valuation should be based on some assumptions since some significant or all inputs to be used in the model are not observable in the market, the in-house derived model which is developed from the general valuation models, such as Finite Difference Method (“FDM”) or Monte Carlo Simulation.
Input variables		Risk-free market rate, forward rate, volatility, foreign exchange rate, stock prices, etc.		Risk-free market rate, forward rate, volatility, foreign exchange rate, stock prices, etc.
Derivative assets | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Derivative financial assets		₩ 0		₩ 0
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0		0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0		0
Derivative assets | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Derivative financial assets		12,395,000,000		59,272,000,000
Financial liabilities at fair value through profit or loss [Abstract]
Transfers out of level1 into level2 of fair value hierarchy assets	[2]	0		0
Transfers out of level2 into level1 of fair value hierarchy assets	[2]	0		0
Derivative assets | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Derivative financial assets		₩ 0		₩ 0
Financial liabilities | Level 1
Fair value of financial instruments measured at fair value [Line Items]
Description of level of fair value hierarchy within which fair value measurement is categorised		Level 1—fair value measurements are those derived from quoted prices (unadjusted) in active markets for identical assets or liabilities. The types of financial assets or liabilities generally included in Level 1 are publicly traded equity securities, derivatives, and debt securities issued by governmental bodies		Level 1—fair value measurements are those derived from quoted prices (unadjusted) in active markets for identical assets or liabilities. The types of financial assets or liabilities generally included in Level 1 are publicly traded equity securities, derivatives, and debt securities issued by governmental bodies
Financial liabilities at fair value through profit or loss [Abstract]
Total		₩ 27,754,000,000		₩ 28,577,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]	0		0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]	₩ 0		₩ 0
Financial liabilities | Level 2
Fair value of financial instruments measured at fair value [Line Items]
Description of level of fair value hierarchy within which fair value measurement is categorised		Level 2— fair value measurements are those derived from inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly (i.e. prices) or indirectly (i.e. derived from prices). The types of financial assets or liabilities generally included in Level 2 are debt securities not traded in active markets and derivatives traded in OTC but not required significant judgment.		Level 2— fair value measurements are those derived from inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly (i.e. prices) or indirectly (i.e. derived from prices). The types of financial assets or liabilities generally included in Level 2 are debt securities not traded in active markets and derivatives traded in OTC but not required significant judgment.
Financial liabilities at fair value through profit or loss [Abstract]
Total		₩ 2,401,063,000,000		₩ 3,286,078,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]	0		0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]	₩ 0		₩ 0
Financial liabilities | Level 3
Fair value of financial instruments measured at fair value [Line Items]
Description of level of fair value hierarchy within which fair value measurement is categorised		Level 3— fair value measurements are those derived from valuation technique that include inputs for the asset or liability that are not based on observable market data (unobservable inputs). The types of financial assets or liabilities generally included in Level 3 are non-public securities and derivatives and debt securities of which valuation techniques require significant judgments and subjectivity		Level 3— fair value measurements are those derived from valuation technique that include inputs for the asset or liability that are not based on observable market data (unobservable inputs). The types of financial assets or liabilities generally included in Level 3 are non-public securities and derivatives and debt securities of which valuation techniques require significant judgments and subjectivity
Financial liabilities at fair value through profit or loss [Abstract]
Total		₩ 217,020,000,000		₩ 181,008,000,000
Financial liabilities held for trading | Level 1
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities held for trading				28,577,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]			0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]			0
Financial liabilities held for trading | Level 2
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities held for trading				3,126,585,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]			0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]			0
Financial liabilities held for trading | Level 3
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities held for trading				20,951,000,000
Deposits due to customers
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities held for trading				25,964,000,000
Deposits due to customers | Level 1
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities held for trading				25,964,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]			0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]			0
Deposits due to customers | Level 2
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities held for trading				0
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]			0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]			0
Deposits due to customers | Level 3
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities held for trading				0
Derivative liabilities
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities held for trading				₩ 3,150,149,000,000
Fair value measurement methods				The in-house developed model which is based on the models that are used by market participants in the valuation of general OTC derivative products, such as options, interest rate swaps, currency swap and currency forward that are based on inputs observable in the market. However, for some complicated financial instruments of which valuation should be based on some assumptions since some significant or all inputs to be used in the model are not observable in the market, the in-house derived model which is developed from the general valuation models, such as Finite Difference Method (“FDM”) or Monte Carlo Simulation.
Input variables				Risk-free market rate, forward rate, volatility, foreign exchange rate, stock prices, etc.
Derivative liabilities | Level 1
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities held for trading				₩ 2,613,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]			0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]			0
Derivative liabilities | Level 2
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities held for trading				3,126,585,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]			0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]			0
Derivative liabilities | Level 3
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities held for trading				20,951,000,000
Financial liabilities designated at FVTPL | Level 1
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount Financial liabilities designated as at FVTPL (IAS39)				0
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]			0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]			0
Financial liabilities designated at FVTPL | Level 2
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount Financial liabilities designated as at FVTPL (IAS39)				91,739,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]			0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]			0
Financial liabilities designated at FVTPL | Level 3
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount Financial liabilities designated as at FVTPL (IAS39)				160,057,000,000
Equity linked securities
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount Financial liabilities designated as at FVTPL (IAS39)				₩ 160,057,000,000
Fair value measurement methods				The fair value of security linked to stock prices or derivatives is measured by the models such as DCF model, FDM, or Monte Carlo Simulation given the natures of the securities or underlying assets.
Input variables				Values of underlying assets, Risk-free market rate, Market rate, Dividend and convenience yield, Correlation, Volatility, Credit spread, and Foreign Exchange rate
Equity linked securities | Level 1
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount Financial liabilities designated as at FVTPL (IAS39)				₩ 0
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]			0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]			0
Equity linked securities | Level 2
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount Financial liabilities designated as at FVTPL (IAS39)				0
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]			0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]			0
Equity linked securities | Level 3
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount Financial liabilities designated as at FVTPL (IAS39)				160,057,000,000
Debentures
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount Financial liabilities designated as at FVTPL (IAS39)				₩ 91,739,000,000
Fair value measurement methods				The fair value is measured by discounting the projected cash flows of a debenture by applying the market discount rate that is reflecting credit rating of the Group.
Input variables				Risk-free market rate, Forward rate
Debentures | Level 1
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount Financial liabilities designated as at FVTPL (IAS39)				₩ 0
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]			0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]			0
Debentures | Level 2
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount Financial liabilities designated as at FVTPL (IAS39)				91,739,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]			0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]			0
Debentures | Level 3
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount Financial liabilities designated as at FVTPL (IAS39)				₩ 0
Financial liabilities at fair value through profit or loss mandatorily measured at fair value | Level 1
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at FVTPL		27,754,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]	0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]	0
Financial liabilities at fair value through profit or loss mandatorily measured at fair value | Level 2
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at FVTPL		2,333,558,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]	0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]	0
Financial liabilities at fair value through profit or loss mandatorily measured at fair value | Level 3
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at FVTPL		40,923,000,000
Deposits
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at FVTPL		24,485,000,000
Deposits | Level 1
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at FVTPL		24,485,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]	0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]	0
Deposits | Level 2
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at FVTPL		0
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]	0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]	0
Deposits | Level 3
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at FVTPL		0
Derivative liabilities
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at FVTPL		₩ 2,377,750,000,000
Fair value measurement methods		The in-house developed model which is based on the models that are used by market participants in the valuation of general OTC derivative products, such as options, interest rate swaps, currency swap and currency forward that are based on inputs observable in the market. However, for some complicated financial instruments of which valuation should be based on some assumptions since some significant or all inputs to be used in the model are not observable in the market, the in-house derived model which is developed from the general valuation models, such as Finite Difference Method (“FDM”) or Monte Carlo Simulation.
Input variables		Risk-free market rate, forward rate, volatility, foreign exchange rate, stock prices, etc.
Derivative liabilities | Level 1
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at FVTPL		₩ 3,269,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]	0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]	0
Derivative liabilities | Level 2
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at FVTPL		2,333,558,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]	0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]	0
Derivative liabilities | Level 3
Financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at FVTPL		₩ 40,923,000,000
Equity-linked securities
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods		The fair value of security linked to stock prices or derivatives is measured by the models such as DCF model, FDM, or Monte Carlo Simulation given the natures of the securities or underlying assets.
Input variables		Values of underlying assets, Risk-free market rate, Market rate, Dividend and convenience yield, Correlation, Volatility, Credit spread, and Foreign Exchange rate
Equity-linked securities | Level 1
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount		₩ 0
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]	0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]	0
Equity-linked securities | Level 2
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount		0
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]	0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]	0
Equity-linked securities | Level 3
Financial liabilities at fair value through profit or loss [Abstract]
Carrying amount		₩ 176,097,000,000
Derivative Liabilities
Financial liabilities at fair value through profit or loss [Abstract]
Fair value measurement methods		The in-house developed model which is based on the models that are used by market participants in the valuation of general OTC derivative products, such as options, interest rate swaps, currency swap and currency forward that are based on inputs observable in the market. However, for some complicated financial instruments of which valuation should be based on some assumptions since some significant or all inputs to be used in the model are not observable in the market, the in-house derived model which is developed from the general valuation models, such as Finite Difference Method (“FDM”) or Monte Carlo Simulation.		The in-house developed model which is based on the models that are used by market participants in the valuation of general OTC derivative products, such as options, interest rate swaps, currency swap and currency forward that are based on inputs observable in the market. However, for some complicated financial instruments of which valuation should be based on some assumptions since some significant or all inputs to be used in the model are not observable in the market, the in-house derived model which is developed from the general valuation models, such as Finite Difference Method (“FDM”) or Monte Carlo Simulation.
Input variables		Risk-free market rate, forward rate, volatility, foreign exchange rate, stock prices, etc.		Risk-free market rate, forward rate, volatility, foreign exchange rate, stock prices, etc.
Derivative Liabilities | Level 1
Financial liabilities at fair value through profit or loss [Abstract]
Derivative financial liabilities		₩ 0		₩ 0
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]	0		0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]	0		0
Derivative Liabilities | Level 2
Financial liabilities at fair value through profit or loss [Abstract]
Derivative financial liabilities		67,505,000,000		67,754,000,000
Transfers out of level1 into level2 of fair value hierarchy liabilities	[2]	0		0
Transfers out of level2 into level1 of fair value hierarchy liabilities	[2]	0		0
Derivative Liabilities | Level 3
Financial liabilities at fair value through profit or loss [Abstract]
Derivative financial liabilities		₩ 0		₩ 0
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.
[2]	There were no transfers between Level 1 and Level 2 of financial assets and liabilities measured at fair value. The Group recognizes transfers among levels at the end of reporting period in which events have occurred or conditions have changed.
[3]	Certain AFS unquoted equity securities were measured at cost as of December 31, 2017, that amounted to 37,092 million Won. These unquoted equity instruments mostly represent minority investments in structured entity vehicles, such as asset securitization structures. They are measured at cost because (a) observable inputs of financial information to measure fair value were not available to obtain, (b) there was a significant variance in likely estimated cash flows or (c) the probabilities for various estimated cash flows could not be measured reliably. In addition, the Group has no intention to dispose these investments in the foreseeable future.

Fair value of financial asse159

Fair value of financial assets and liabilities_Details of financial assets and liabilities classified into Level 3 of fair value hierarchy (Details) - KRW (₩)		6 Months Ended				12 Months Ended
		Jun. 30, 2018		Jun. 30, 2017		Dec. 31, 2017
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Gains losses from financial assets and liabilities classified as level3 that the group holds as at the end of the year		₩ 61,323,000,000	[1]	₩ 61,518,000,000	[2]
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Unfavorable changes in unobservable inputs in other comprehensive income		The sensitivity analysis of the financial instruments has been performed by classifying with favorable and unfavorable changes based on how changes in unobservable assumptions would have effects on the fluctuations of financial instruments’ value. When the fair value of a financial instrument is affected by more than one unobservable assumption, the below table reflects the most favorable or the most unfavorable changes which resulted from varying the assumptions individually. The sensitivity analysis was performed for two types of level 3 financial instruments: (1) debt securities, equity securities, interest rate related derivatives, currency related derivatives, equity related derivatives, equity-linked securities and beneficiary certificates of which fair value changes are recognized as net income; (2) equity securities of which fair value changes are recognized as other comprehensive income. Equity investments classified as Level 3 equity securities whose costs are considered to provide the best estimate of fair value are excluded from sensitivity analysis. The equity investments classified as Level 3 equity securities whose costs are considered to provide the best estimate of fair value are excluded from sensitivity analysis.		The sensitivity analysis of the financial instruments has been performed by classifying with favorable and unfavorable changes based on how changes in unobservable assumptions would have effects on the fluctuations of financial instruments’ value. When the fair value of a financial instrument is affected by more than one unobservable assumption, the below table reflects the most favorable or the most unfavorable changes which resulted from varying the assumptions individually. The sensitivity analysis was performed for two types of level 3 financial instruments: (1) debt securities, equity securities, interest rate related derivatives, currency related derivatives, equity related derivatives, equity-linked securities and beneficiary certificates of which fair value changes are recognized as net income; (2) equity securities of which fair value changes are recognized as other comprehensive income. Equity investments classified as Level 3 equity securities whose costs are considered to provide the best estimate of fair value are excluded from sensitivity analysis. The equity investments classified as Level 3 equity securities whose costs are considered to provide the best estimate of fair value are excluded from sensitivity analysis.
Financial assets
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance		₩ 1,873,686,000,000		₩ 1,595,698,000,000		₩ 1,595,698,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)		126,709,000,000		44,069,000,000
Other comprehensive income(loss)		14,557,000,000		7,987,000,000
Purchases Issuances		2,152,168,000,000		156,908,000,000
Disposals Settlements		(1,954,754,000,000)		(119,996,000,000)
Transfer to or from level 3	[3]	0		0
Ending balance		2,212,366,000,000		1,684,666,000,000		1,873,686,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)		17,817,000,000				2,169,000,000
Unfavorable changes in unobservable inputs in net income(loss)		(12,665,000,000)				(1,459,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)		19,464,000,000				30,444,000,000
Unfavorable changes in unobservable inputs in other comprehensive income(loss)		(8,704,000,000)				(17,103,000,000)
Financial assets at fair value through profit or loss category in accordance with IAS 39 [Member]
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance				17,000,000,000		17,000,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)				(16,000,000)
Other comprehensive income(loss)				0
Purchases Issuances				2,000,000,000
Disposals Settlements				0
Transfer to or from level 3	[3]			0
Ending balance				₩ 18,984,000,000
Derivative assets
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique				Option valuation model and others
Input variable				Correlation coefficient Volatility of underlying asset
Impact of changes in significant unobservable inputs on fair value measurement				Variation of fair value increases as correlation coefficient increases. Variation of fair value increases as volatility increases.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance				₩ 23,153,000,000		23,153,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)				21,217,000,000
Other comprehensive income(loss)				0
Purchases Issuances				472,000,000
Disposals Settlements				(17,420,000,000)
Transfer to or from level 3	[3]			0
Ending balance				₩ 27,422,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)	[4],[5]					1,234,000,000
Unfavorable changes in unobservable inputs in net income(loss)	[4],[5]					(526,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)						0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)						0
Derivative assets | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset				10.61%
Correlation coefficient				90.00%
Derivative assets | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset				27.59%
Correlation coefficient				97.00%
Debt securities
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance				₩ 4,348,000,000		4,348,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)				191,000,000
Other comprehensive income(loss)				0
Purchases Issuances				2,000,000,000
Disposals Settlements				0
Transfer to or from level 3	[3]			0
Ending balance				₩ 6,539,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)	[6]					265,000,000
Unfavorable changes in unobservable inputs in net income(loss)	[6]					(309,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)						0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)						0
Equity securities
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique				External appraisal value and others
Input variable				Expected growth rate Discount rate Volatility of real estate sale price
Impact of changes in significant unobservable inputs on fair value measurement				Fair value increases as expected growth rate increases. Fair value increases as discount rate decreases. Fair value increases as sale price increases.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance				₩ 12,652,000,000		12,652,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)				(207,000,000)
Other comprehensive income(loss)				0
Purchases Issuances				0
Disposals Settlements				0
Transfer to or from level 3	[3]			0
Ending balance				₩ 12,445,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)	[6]					670,000,000
Unfavorable changes in unobservable inputs in net income(loss)	[6]					(624,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)						0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)						0
Equity securities | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Discount rate				0.99%
Equity securities | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Expected growth rate				0.00%
Volatility of real estate sale price				0.00%
Discount rate				18.73%
AFS financial assets
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance				₩ 1,555,446,000,000		1,555,446,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)				22,683,000,000
Other comprehensive income(loss)				7,987,000,000
Purchases Issuances				154,436,000,000
Disposals Settlements				(102,292,000,000)
Transfer to or from level 3	[3]			0
Ending balance				₩ 1,638,260,000,000
Equity securities
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique				External appraisal value and others
Input variable				Expected growth rate Discount rate Volatility of real estate sale price
Impact of changes in significant unobservable inputs on fair value measurement				Fair value increases as expected growth rate increases. Fair value increases as discount rate decreases. Fair value increases as sale price increases.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance				₩ 1,024,935,000,000		1,024,935,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)				19,241,000,000
Other comprehensive income(loss)				10,175,000,000
Purchases Issuances				27,289,000,000
Disposals Settlements				(31,692,000,000)
Transfer to or from level 3	[3]			0
Ending balance				₩ 1,049,948,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)						0
Unfavorable changes in unobservable inputs in net income(loss)						0
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)	[7],[8]					28,583,000,000
Unfavorable changes in unobservable inputs in other comprehensive income(loss)	[7],[8]					(15,246,000,000)
Equity securities | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Discount rate				0.99%
Equity securities | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Expected growth rate				0.00%
Volatility of real estate sale price				0.00%
Discount rate				18.73%
Beneficiary certificates
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique				External appraisal value and others
Input variable				Expected growth rate Discount rate Volatility of real estate sale price
Impact of changes in significant unobservable inputs on fair value measurement				Fair value increases as expected growth rate increases. Fair value increases as discount rate decreases. Fair value increases as sale price increases.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance				₩ 530,511,000,000		530,511,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)				3,442,000,000
Other comprehensive income(loss)				(2,188,000,000)
Purchases Issuances				127,147,000,000
Disposals Settlements				(70,600,000,000)
Transfer to or from level 3	[3]			0
Ending balance				₩ 588,312,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)						0
Unfavorable changes in unobservable inputs in net income(loss)						0
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)	[7]					1,861,000,000
Unfavorable changes in unobservable inputs in other comprehensive income(loss)	[7]					(1,857,000,000)
Beneficiary certificates | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Discount rate				0.99%
Beneficiary certificates | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Expected growth rate				0.00%
Volatility of real estate sale price				0.00%
Discount rate				18.73%
Financial assets at FVTPL (IFRS 9)
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance		1,422,399,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)		127,102,000,000
Other comprehensive income(loss)		0
Purchases Issuances		2,151,878,000,000
Disposals Settlements		(1,954,754,000,000)
Transfer to or from level 3	[3]	0
Ending balance		1,746,625,000,000				1,422,399,000,000
Debt securities
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance		9,694,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)		(111,000,000)
Other comprehensive income(loss)		0
Purchases Issuances		0
Disposals Settlements		(2,141,000,000)
Transfer to or from level 3	[3]	0
Ending balance		7,442,000,000				9,694,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)		914,000,000
Unfavorable changes in unobservable inputs in net income(loss)		(784,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)		0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)		₩ 0
Equity securities
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique		External appraisal value and others
Input variable		Expected growth rate Discount rate Volatility of real estate sale price
Impact of changes in significant unobservable inputs on fair value measurement		Fair value increases as expected growth rate increases. Fair value increases as discount rate decreases. Fair value increases as sale price increases.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance		₩ 280,171,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)		22,834,000,000
Other comprehensive income(loss)		0
Purchases Issuances		50,005,000,000
Disposals Settlements		(230,000,000)
Transfer to or from level 3	[3]	0
Ending balance		352,780,000,000				280,171,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)	[7],[8]	10,740,000,000
Unfavorable changes in unobservable inputs in net income(loss)	[7],[8]	(7,562,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)		0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)		₩ 0
Equity securities | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Discount rate		0.99%
Equity securities | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Expected growth rate		0.00%
Volatility of real estate sale price		0.00%
Discount rate		18.73%
Capital contributions
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance		₩ 294,121,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)		21,934,000,000
Other comprehensive income(loss)		0
Purchases Issuances		49,367,000,000
Disposals Settlements		(15,952,000,000)
Transfer to or from level 3	[3]	0
Ending balance		₩ 349,470,000,000				294,121,000,000
Beneficiary certificates
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique		External appraisal value and others
Input variable		Expected growth rate Discount rate Volatility of real estate sale price
Impact of changes in significant unobservable inputs on fair value measurement		Fair value increases as expected growth rate increases. Fair value increases as discount rate decreases. Fair value increases as sale price increases.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance		₩ 654,066,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)		12,973,000,000
Other comprehensive income(loss)		0
Purchases Issuances		1,924,763,000,000
Disposals Settlements		(1,843,007,000,000)
Transfer to or from level 3	[3]	0
Ending balance		748,795,000,000				654,066,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)	[7]	1,436,000,000
Unfavorable changes in unobservable inputs in net income(loss)	[7]	(1,544,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)		0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)		₩ 0
Beneficiary certificates | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Discount rate		0.99%
Beneficiary certificates | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Expected growth rate		0.00%
Volatility of real estate sale price		0.00%
Discount rate		18.73%
Loans
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique		Binomial tree
Input variable		Stock, Volatility of underlying
Impact of changes in significant unobservable inputs on fair value measurement		Variation of fair value increases as volatility increases.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance		₩ 165,001,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)		3,616,000,000
Other comprehensive income(loss)		0
Purchases Issuances		125,807,000,000
Disposals Settlements		(42,457,000,000)
Transfer to or from level 3	[3]	0
Ending balance		251,967,000,000				165,001,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)		422,000,000
Unfavorable changes in unobservable inputs in net income(loss)		(323,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)		0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)		₩ 0
Unfavorable changes in unobservable inputs in other comprehensive income
Loans | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset		14.92%
Loans | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset		41.24%
Derivative instrument assets
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique		Option valuation model and others
Input variable		Correlation coefficient Volatility of underlying asset
Impact of changes in significant unobservable inputs on fair value measurement		Variation of fair value increases as correlation coefficient increases. Variation of fair value increases as volatility increases.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance		₩ 19,346,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)		65,856,000,000
Other comprehensive income(loss)		0
Purchases Issuances		1,936,000,000
Disposals Settlements		(50,967,000,000)
Transfer to or from level 3	[3]	0
Ending balance		36,171,000,000				19,346,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)	[4],[5]	4,305,000,000
Unfavorable changes in unobservable inputs in net income(loss)	[4],[5]	(2,452,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)		0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)		₩ 0
Derivative instrument assets | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset		10.61%
Correlation coefficient		90.00%
Derivative instrument assets | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset		27.59%
Correlation coefficient		97.00%
Equity securities
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique		External appraisal value and others
Input variable		Expected growth rate Discount rate Volatility of real estate sale price
Impact of changes in significant unobservable inputs on fair value measurement		Fair value increases as expected growth rate increases. Fair value increases as discount rate decreases. Fair value increases as sale price increases.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance		₩ 451,287,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)		(393,000,000)
Other comprehensive income(loss)		14,557,000,000
Purchases Issuances		290,000,000
Disposals Settlements		0
Transfer to or from level 3	[3]	0
Ending balance		465,741,000,000				451,287,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)		0
Unfavorable changes in unobservable inputs in net income(loss)		0
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)	[7],[8]	19,464,000,000
Unfavorable changes in unobservable inputs in other comprehensive income(loss)	[7],[8]	₩ (8,704,000,000)
Equity securities | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Discount rate		0.99%
Equity securities | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Expected growth rate		0.00%
Volatility of real estate sale price		0.00%
Discount rate		18.73%
Derivative assets
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique				Option valuation model and others
Input variable				Correlation coefficient Volatility of underlying asset
Impact of changes in significant unobservable inputs on fair value measurement				Variation of fair value increases as correlation coefficient increases. Variation of fair value increases as volatility increases.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance				₩ 99,000,000		99,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)				185,000,000
Other comprehensive income(loss)				0
Purchases Issuances				0
Disposals Settlements				(284,000,000)
Transfer to or from level 3	[3]			₩ 0
Derivative assets | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset				10.61%
Correlation coefficient				90.00%
Derivative assets | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset				27.59%
Correlation coefficient				97.00%
Financial liabilities
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance		₩ 181,008,000,000		₩ 707,233,000,000		707,233,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)		72,513,000,000		98,104,000,000
Other comprehensive income(loss)		0		0
Purchases Issuances		175,986,000,000		501,000,000
Disposals Settlements		(212,487,000,000)		(250,311,000,000)
Transfer to or from level 3	[3]	0		0
Ending balance		217,020,000,000		₩ 555,527,000,000		181,008,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)		3,492,000,000				13,000,000
Unfavorable changes in unobservable inputs in net income(loss)		(5,443,000,000)				(520,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)		0				0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)		₩ 0				0
Derivative liabilities
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique				Option valuation model and others
Input variable				Correlation coefficient Volatility of underlying asset
Impact of changes in significant unobservable inputs on fair value measurement				Variation of fair value increases as correlation coefficient increases. Variation of fair value increases as volatility increases.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance				₩ 33,524,000,000		33,524,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)				14,142,000,000
Other comprehensive income(loss)				0
Purchases Issuances				501,000,000
Disposals Settlements				(15,015,000,000)
Transfer to or from level 3	[3]			0
Ending balance				₩ 33,152,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)	[4],[5]					5,000,000
Unfavorable changes in unobservable inputs in net income(loss)	[4],[5]					(513,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)						0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)						0
Derivative liabilities | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset				10.61%
Correlation coefficient				90.00%
Derivative liabilities | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset				27.59%
Correlation coefficient				97.00%
Equity linked securities
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique				Monte Carlo Simulation and others
Input variable				Correlation coefficient Volatility of underlying asset
Impact of changes in significant unobservable inputs on fair value measurement				Equity-linked securities’ variation of fair value increases if both volatility and correlation coefficient increase. However, when correlation coefficient decreases despite the increase in volatility, the variation of fair value of a compound financial instrument may decrease.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance				₩ 673,709,000,000		673,709,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)				83,962,000,000
Other comprehensive income(loss)				0
Purchases Issuances				0
Disposals Settlements				(235,296,000,000)
Transfer to or from level 3	[3]			0
Ending balance				₩ 522,375,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)	[5]					8,000,000
Unfavorable changes in unobservable inputs in net income(loss)	[5]					(7,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)						0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)						0
Equity linked securities | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset				18.60%
Correlation coefficient				8.61%
Equity linked securities | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset				26.88%
Correlation coefficient				68.80%
Derivative liabilities
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique		Option valuation model and others
Input variable		Correlation coefficient Volatility of underlying asset
Impact of changes in significant unobservable inputs on fair value measurement		Variation of fair value increases as correlation coefficient increases. Variation of fair value increases as volatility increases.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance		₩ 20,951,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)		73,951,000,000
Other comprehensive income(loss)		0
Purchases Issuances		(3,058,000,000)
Disposals Settlements		(50,921,000,000)
Transfer to or from level 3	[3]	0
Ending balance		40,923,000,000				20,951,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)	[4],[5]	2,409,000,000
Unfavorable changes in unobservable inputs in net income(loss)	[4],[5]	(4,285,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)		0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)		₩ 0
Derivative liabilities | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset		10.61%
Correlation coefficient		90.00%
Derivative liabilities | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset		27.59%
Correlation coefficient		97.00%
Equity-linked securities
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Fair value measurement technique		Monte Carlo Simulation and others
Input variable		Correlation coefficient Volatility of underlying asset
Impact of changes in significant unobservable inputs on fair value measurement		Equity-linked securities’ variation of fair value increases if both volatility and correlation coefficient increase. However, when correlation coefficient decreases despite the increase in volatility, the variation of fair value of a compound financial instrument may decrease.
Reconciliation of changes in level3 of fair value hierarchy [Abstract]
Beginning balance		₩ 160,057,000,000
Changes in financial assets liabilities measured at fair value level3 of the fair value hierarchy [Abstract]
Net Income(loss)		(1,438,000,000)
Other comprehensive income(loss)		0
Purchases Issuances		179,044,000,000
Disposals Settlements		(161,566,000,000)
Transfer to or from level 3	[3]	0
Ending balance		176,097,000,000				₩ 160,057,000,000
Changes in unobservable inputs financial assets liabilities recognition in profit or loss [Abstract]
Favorable changes in unobservable inputs in net income(loss)	[5]	1,083,000,000
Unfavorable changes in unobservable inputs in net income(loss)	[5]	(1,158,000,000)
Changes in unobservable inputs financial assets liabilities recognition in other comprehensive income [Abstract]
Favorable changes in unobservable inputs in other comprehensive income(loss)		0
Unfavorable changes in unobservable inputs in other comprehensive income(loss)		₩ 0
Equity-linked securities | Bottom of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset		18.60%
Correlation coefficient		8.61%
Equity-linked securities | Top of range [Member]
Disclosure of significant unobservable inputs used in fair value measurement of financial instruments [Abstract]
Volatility of underlying asset		26.88%
Correlation coefficient		68.80%
[1]	The losses that increase financial liabilities are presented as positive amounts, and the gains that decrease financial liabilities are presented as negative amounts. The gain amounting to 61,323 million Won for six months ended June 30, 2018, which is from financial assets and liabilities that the Group holds as at the end of the periods, has been recognized in net gain (loss) on financial assets at FVTPL and net gain (loss) on financial assets at FVTOCI in the consolidated statement of comprehensive income.
[2]	The loss amounting to 61,518 million Won for the six months ended June 30, 2017, which is from financial assets and liabilities that the Group holds, has been recognized in net gain (loss) on financial instruments at FVTPL and net gain (loss) on AFS financial assets in the statement of comprehensive income. The loss amounting to 61,518 million Won for the six months ended June 30, 2017, which is from financial assets and liabilities that the Group holds, has been recognized in net gain (loss) on financial instruments at FVTPL and net gain (loss) on AFS financial assets in the statement of comprehensive income.
[3]	The Group recognizes transfers between levels at the end of reporting period within which events have occurred or conditions have changed.
[4]	Both derivative assets and liabilities for held for trading and hedging are included.
[5]	Fair value changes of equity related derivatives assets and liabilities and equity-linked securities are calculated by increasing or decreasing historical volatility of the stock price and correlation, which are major unobservable variables, by 10%, respectively. In the case of interest rate related derivative assets and liabilities, fair value changes are calculated by increasing or decreasing the volatility of interest rate, which are major unobservable variables, by 10%.
[6]	Changes of fair value are measured by increasing or decreasing the discount rate by 10%, which is major unobservable variable, respectively.
[7]	Even if the sensitivity analysis of the capital contributions and beneficiary certificates is not possible in practice, fair value changes of beneficiary certificates and other securities whose major unobservable variables are composed of the real estate are calculated by increasing or decreasing price fluctuation of real estate which is underlying assets and discount rate by 1%.
[8]	Fair value changes of equity securities are calculated by increasing or decreasing growth rate (0~1%) and discount rate or liquidation value (-1~1%). The growth rate, discount rate, and liquidation value are major unobservable variables.

Fair value of financial asse160

Fair value of financial assets and liabilities_Fair value and carrying amount of financial assets and liabilities measured at amortized cost (Details)	6 Months Ended		12 Months Ended
	Jun. 30, 2018KRW (₩)		Dec. 31, 2017KRW (₩)	Jun. 30, 2018USD ($)
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Securities at amortized cost	₩ 17,703,477,000,000
Loans and other financial assets at amortized cost	277,718,440,000,000
Held-to-maturity financial assets			₩ 16,715,679,000,000
Loans and receivables			265,570,649,000,000
Deposits due to customers	237,811,780,000,000		234,682,775,000,000
Borrowings	15,924,417,000,000		14,754,506,000,000
Debentures	26,586,897,000,000		27,889,781,000,000
Other financial liabilities	21,405,921,000,000		13,890,789,000,000
Carrying value of financial assets liabilities measured at amortised cost [Abstract]
Securities at amortized cost	17,702,129,000,000	[1]	0	$ 15,922,044,000
Loans and other financial assets at amortized cost	277,720,003,000,000	[1]	0	249,793,131,000
Held-to-maturity financial assets	0		16,749,296,000,000	0
Loans and receivables	0		267,106,204,000,000	0
Deposits due to customers	237,900,166,000,000		234,695,084,000,000	213,977,483,000
Borrowings	15,899,599,000,000		14,784,706,000,000	14,300,773,000
Debentures	26,752,725,000,000		27,869,651,000,000	24,062,534,000
Other financial liabilities	₩ 21,408,267,000,000		₩ 13,892,461,000,000	$ 19,255,502,000
Securities at amortized cost
Disclosure of financial assets liabilities measured at amortised [Abstract]
Fair value measurement technique	The fair value is measured by discounting the projected cash flows of debt securities by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the issuers of the securities.
Input variables	Risk-free market rate and credit spread
Securities at amortized cost | Level 1
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Securities at amortized cost	₩ 1,792,215,000,000
Securities at amortized cost | Level 2
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Securities at amortized cost	15,911,262,000,000
Securities at amortized cost | Level 3
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Securities at amortized cost	₩ 0
Loans and other financial assets at amortized cost
Disclosure of financial assets liabilities measured at amortised [Abstract]
Fair value measurement technique	The fair value is measured by discounting the projected cash flows of loan products by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the debtor.
Input variables	Risk-free market rate, credit spread and prepayment-rate
Loans and other financial assets at amortized cost | Level 1
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Loans and other financial assets at amortized cost	₩ 0
Loans and other financial assets at amortized cost | Level 2
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Loans and other financial assets at amortized cost	0
Loans and other financial assets at amortized cost | Level 3
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Loans and other financial assets at amortized cost	₩ 277,718,440,000,000
HTM financial assets
Disclosure of financial assets liabilities measured at amortised [Abstract]
Fair value measurement technique			The fair value is measured by discounting the projected cash flows of debt securities by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the issuers of the securities.
Input variables			Risk-free market rate, Credit spread
HTM financial assets | Level 1
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Held-to-maturity financial assets			₩ 1,206,292,000,000
HTM financial assets | Level 2
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Held-to-maturity financial assets			15,509,387,000,000
HTM financial assets | Level 3
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Held-to-maturity financial assets			₩ 0
Loans
Disclosure of financial assets liabilities measured at amortised [Abstract]
Fair value measurement technique			The fair value is measured by discounting the projected cash flows of loan products by applying the market discount rate that has been applied to a proxy company that has similar credit rating to the debtor.
Input variables			Risk-free market rate, Credit spread, Prepayment-rate
Loans | Level 1
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Loans and receivables			₩ 0
Loans | Level 2
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Loans and receivables			0
Loans | Level 3
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Loans and receivables			₩ 265,570,649,000,000
Deposits due to customers
Disclosure of financial assets liabilities measured at amortised [Abstract]
Fair value measurement technique	The fair value is measured by discounting the projected cash flows of debt products by applying the market discount rate that is reflecting the credit rating of the Group.		The fair value is measured by discounting the projected cash flows of debt products by applying the market discount rate that is reflecting the credit rating of the Group.
Input variables	Risk-free market rate and forward rate Risk-free market rate and forward rate		Risk-free market rate, Forward rate
Deposits due to customers | Level 1
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Deposits due to customers	₩ 0		₩ 0
Deposits due to customers | Level 2
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Deposits due to customers	237,811,780,000,000		234,682,775,000,000
Deposits due to customers | Level 3
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Deposits due to customers	₩ 0		₩ 0
Borrowings
Disclosure of financial assets liabilities measured at amortised [Abstract]
Fair value measurement technique	The fair value is measured by discounting the projected cash flows of debt products by applying the market discount rate that is reflecting the credit rating of the Group.		The fair value is measured by discounting the projected cash flows of debt products by applying the market discount rate that is reflecting the credit rating of the Group.
Input variables	Risk-free market rate and forward rate		Risk-free market rate, Forward rate
Borrowings | Level 1
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Borrowings	₩ 0		₩ 0
Borrowings | Level 2
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Borrowings	15,924,417,000,000		14,754,506,000,000
Borrowings | Level 3
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Borrowings	₩ 0		₩ 0
Debentures
Disclosure of financial assets liabilities measured at amortised [Abstract]
Fair value measurement technique	The fair value is measured by discounting the projected cash flows of debt products by applying the market discount rate that is reflecting the credit rating of the Group.		The fair value is measured by discounting the projected cash flows of debt products by applying the market discount rate that is reflecting the credit rating of the Group.
Input variables	Risk-free market rate and forward rate		Risk-free market rate, Forward rate
Debentures | Level 1
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Debentures	₩ 0		₩ 0
Debentures | Level 2
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Debentures	26,586,897,000,000		27,889,781,000,000
Debentures | Level 3
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Debentures	₩ 0		₩ 0
Other financial liabilities
Disclosure of financial assets liabilities measured at amortised [Abstract]
Fair value measurement technique	The fair value is measured by discounting the projected cash flows of debt products by applying the market discount rate that is reflecting the credit rating of the Group.		The fair value is measured by discounting the projected cash flows of debt products by applying the market discount rate that is reflecting the credit rating of the Group.
Input variables	Risk-free market rate and forward rate		Risk-free market rate, Forward rate
Other financial liabilities | Level 1
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Other financial liabilities	₩ 0		₩ 0
Other financial liabilities | Level 2
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Other financial liabilities	21,405,921,000,000		13,890,789,000,000
Other financial liabilities | Level 3
Fair value of financial assets liabilities measured at amortised cost [Abstract]
Other financial liabilities	₩ 0		₩ 0
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.

Fair value of financial asse161

Fair value of financial assets and liabilities_Financial assets by category (Details)	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)		Dec. 31, 2017KRW (₩)
Disclosure of financial assets [Line Items]
Financial assets at FVTPL	₩ 6,340,704,000,000	[1]	$ 5,703,098,000	[1]	₩ 0
Financial assets at FVTPL (IAS 39)	0		0		5,843,077,000,000
Financial assets at FVTOCI	14,644,608,000,000	[1]	13,171,981,000	[1]	0
AFS financial assets	0		0		15,352,950,000,000
Financial assets at amortized cost	295,422,132,000,000
Held-to-maturity financial assets	0		0		16,749,296,000,000
Loans and receivables	0		0		267,106,204,000,000
Derivative assets for hedging	12,395,000,000		$ 11,149,000		59,272,000,000
Total	316,419,839,000,000				305,110,799,000,000
Deposits
Disclosure of financial assets [Line Items]
Financial assets at FVTPL	24,921,000,000
Financial assets at FVTPL (IAS 39)					25,972,000,000
Financial assets at amortized cost	17,770,356,000,000
Loans and receivables					8,868,378,000,000
Total	17,795,277,000,000				8,894,350,000,000
Securities at fair value through profit or loss
Disclosure of financial assets [Line Items]
Financial assets at FVTPL	3,587,605,000,000
Financial assets at FVTPL (IAS 39)					2,701,330,000,000
Total	3,587,605,000,000				2,701,330,000,000
Securities at FVTOCI
Disclosure of financial assets [Line Items]
Financial assets at FVTOCI	14,644,608,000,000
Total	14,644,608,000,000
AFS financial assets
Disclosure of financial assets [Line Items]
AFS financial assets					15,352,950,000,000
Total					15,352,950,000,000
Securities at amortized cost
Disclosure of financial assets [Line Items]
Financial assets at amortized cost	17,702,129,000,000
Total	17,702,129,000,000
HTM financial assets
Disclosure of financial assets [Line Items]
Held-to-maturity financial assets	0				16,749,296,000,000
Total					16,749,296,000,000
Loans
Disclosure of financial assets [Line Items]
Financial assets at FVTPL	336,967,000,000
Financial assets at amortized cost	248,794,014,000,000
Loans and receivables					251,523,301,000,000
Total	249,130,981,000,000				251,523,301,000,000
Derivatives instruments assets
Disclosure of financial assets [Line Items]
Financial assets at FVTPL	2,391,211,000,000
Financial assets at FVTPL (IAS 39)					3,115,775,000,000
Derivative assets for hedging	12,395,000,000				59,272,000,000
Total	2,403,606,000,000				3,175,047,000,000
Loans and receivables (Other financial assets)
Disclosure of financial assets [Line Items]
Financial assets at amortized cost	11,155,633,000,000
Loans and receivables					6,714,525,000,000
Total	₩ 11,155,633,000,000				₩ 6,714,525,000,000
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.

Fair value of financial asse162

Fair value of financial assets and liabilities_Financial liabilities by category (Details)	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)		Dec. 31, 2017KRW (₩)
Disclosure of financial liabilities [Line Items]
Financial liabilities at FVTPL	₩ 2,578,332,000,000	[1]	$ 2,319,061,000	[1]	₩ 0
Financial liabilities at FVTPL in accordance with IAS 39	0		0		3,427,909,000,000
Financial liabilities at amortized cost	302,015,653,000,000				291,313,599,000,000
Derivative liabilities for hedging	67,505,000,000		$ 60,717,000		67,754,000,000
Total	304,661,490,000,000				294,809,262,000,000
Deposits due to customer
Disclosure of financial liabilities [Line Items]
Financial liabilities at FVTPL	24,485,000,000
Financial liabilities at FVTPL in accordance with IAS 39					25,964,000,000
Financial liabilities at amortized cost	237,900,166,000,000				234,695,084,000,000
Total	237,924,651,000,000				234,721,048,000,000
Borrowing
Disclosure of financial liabilities [Line Items]
Financial liabilities at FVTPL	176,097,000,000
Financial liabilities at FVTPL in accordance with IAS 39					160,057,000,000
Financial liabilities at amortized cost	15,899,599,000,000				14,784,706,000,000
Total	16,075,696,000,000				14,944,763,000,000
Debentures
Disclosure of financial liabilities [Line Items]
Financial liabilities at FVTPL in accordance with IAS 39					91,739,000,000
Financial liabilities at amortized cost	26,752,725,000,000				27,869,651,000,000
Total	26,752,725,000,000				27,961,390,000,000
Derivatives (for trading)
Disclosure of financial liabilities [Line Items]
Financial liabilities at FVTPL	2,377,750,000,000
Financial liabilities at FVTPL in accordance with IAS 39					3,150,149,000,000
Derivative liabilities for hedging	67,505,000,000				67,754,000,000
Total	2,445,255,000,000				3,217,903,000,000
Other financial liabilities
Disclosure of financial liabilities [Line Items]
Financial liabilities at amortized cost	21,463,163,000,000	[2]			13,964,158,000,000	[3]
Total	21,463,163,000,000	[2]			13,964,158,000,000	[3]
Financial guarantee liabilities measured at amortized cost	₩ 54,896,000,000	[2]			₩ 71,697,000,000	[3]
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.
[2]	Other financial liabilities include 54,896 million Won of financial guarantee liabilities measured at amortized cost included in provisions (Note23).
[3]	Other financial liabilities include 71,697 million Won of financial guarantee liabilities measured at amortized cost included in provisions (Note23).

Derecognition And Offset Of 163

Derecognition And Offset Of Financial Instruments_Transferred financial assets that do not meet the condition of derecognition in their entirety (Details) - KRW (₩)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Nature of financial assets transferred during period which do not qualify for derecognition
Assets transferred
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Nature of financial assets transferred during period which do not qualify for derecognition	The financial instruments that were disposed but the Group agreed to repurchase at the fixed amounts at the same time, so that they did not meet the conditions of derecognition	The financial instruments that were disposed but the Group agreed to repurchase at the fixed amounts at the same time, so that they did not meet the conditions of derecognition
Assets that entity continues to recognise	₩ 15,446,000,000	₩ 15,434,000,000
Financial assets at FVTOCI
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Assets that entity continues to recognise	10,002,000,000	0
AFS financial assets
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Assets that entity continues to recognise	0	9,998,000,000
Securities at amortized cost
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Assets that entity continues to recognise	5,444,000,000	0
HTM financial assets
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Assets that entity continues to recognise	0	5,436,000,000
Bonds sold under repurchase agreements
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Related liabilities	₩ 5,372,000,000	₩ 3,173,000,000
Loaned securities
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Nature of financial assets transferred during period which do not qualify for derecognition	Securities loaned are lending of specific securities to borrowers who agree to return the same quantity of the same security at the end of lending period. As the Group does not derecognize these securities, there are no liabilities recognized through such transactions relates to securities loaned.	Securities loaned are lending of specific securities to borrowers who agree to return the same quantity of the same security at the end of lending period. As the Group does not derecognize these securities, there are no liabilities recognized through such transactions relates to securities loaned.
Assets that entity continues to recognise	₩ 50,139,000,000	₩ 170,256,000,000
Industrial and financial debt securities and others
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Assets that entity continues to recognise	₩ 50,139,000,000	0
Loaned to	Korea Securities Finance Corporation
Korean treasury and government agencies bonds
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Assets that entity continues to recognise	₩ 0	₩ 170,256,000,000
Loaned to		Korea Securities Finance Corporation and others

Derecognition and offset of 164

Derecognition and offset of financial instruments_Financial assets subject to offset enforceable master netting agreements or similar agreements (Details) - KRW (₩)		6 Months Ended		12 Months Ended
		Jun. 30, 2018		Dec. 31, 2017
Net financial assets subject to offsetting enforceable master netting arrangements or similar agreements in statement of financial position [Abstract]
Gross amounts of recognized financial assets		₩ 44,123,286,000,000		₩ 62,669,493,000,000
Gross amounts of recognized financial assets set off		27,338,204,000,000		38,987,064,000,000
Net amounts of financial assets presented		16,785,082,000,000		23,682,429,000,000
Related amounts not set off in the consolidated statement of financial position
Netting agreements and others		15,716,153,000,000		22,646,512,000,000
Cash collateral received		21,543,000,000		174,415,000,000
Net amounts		₩ 1,047,386,000,000		₩ 861,502,000,000
Description of rights of setoff associated with financial assets subject to enforceable master netting arrangement or similar agreement		The Group possesses both the uncollected domestic exchange receivables and the unpaid domestic exchange payable, which satisfy offsetting criteria of IAS 32. Therefore, the total number of uncollected domestic exchange receivables or unpaid domestic exchange payable has been countervailed with part of unpaid domestic exchange payable or uncollected domestic exchange receivables and has been disclosed in loans at amortized cost and other financial assets (loans and receivables in previous year) or other financial liabilities of the Group’s statements of financial position. The Group possesses the derivative assets, derivative liabilities, receivable spot exchange and payable spot exchange that do not satisfy the offsetting criteria of IAS 32, but provide the Group under the circumstances of the trading party’s defaults, insolvency or bankruptcy, the right of offsetting. Item such as cash collateral cannot satisfy the offsetting criteria of IAS 32, but in accordance with the collateral arrangements and under the circumstances of the trading party’s default, insolvency or bankruptcy, the net amount of derivative assets and derivative liabilities, receivable spot exchange and payable spot exchange can be offset. The Group has entered into a resale and repurchase agreement and accounted it as a collateralized borrowing. The Group has also entered into a resale and purchase agreement and accounted it as a secured advance. The resale and repurchase agreements can have the offsetting right only under the trading party’s default, insolvency or bankruptcy, which do not satisfy the offsetting criteria of IAS 32. The Group recorded the collateralized borrowing in borrowings and the secured loans in loans and receivables. The Group under the repurchase agreements has offsetting right only upon the counterparty’s default, insolvency or bankruptcy; thus, the repurchase agreements are applied by the TBMA/ISMA Global Master Repurchase Agreement, which does not satisfy the offsetting criteria of IAS 32. The Group disclosed bonds sold (purchased) under repurchase(resale) agreements as borrowings loan at amortized cost and other financial assets (loans and receivables in previous year).		The Group possesses both the uncollected domestic exchange receivables and the unpaid domestic exchange payable, which satisfy offsetting criteria of IAS 32. Therefore, the total number of uncollected domestic exchange receivables or unpaid domestic exchange payable has been countervailed with part of unpaid domestic exchange payable or uncollected domestic exchange receivables and has been disclosed in loans at amortized cost and other financial assets (loans and receivables in previous year) or other financial liabilities of the Group’s statements of financial position. The Group possesses the derivative assets, derivative liabilities, receivable spot exchange and payable spot exchange that do not satisfy the offsetting criteria of IAS 32, but provide the Group under the circumstances of the trading party’s defaults, insolvency or bankruptcy, the right of offsetting. Item such as cash collateral cannot satisfy the offsetting criteria of IAS 32, but in accordance with the collateral arrangements and under the circumstances of the trading party’s default, insolvency or bankruptcy, the net amount of derivative assets and derivative liabilities, receivable spot exchange and payable spot exchange can be offset. The Group has entered into a resale and repurchase agreement and accounted it as a collateralized borrowing. The Group has also entered into a resale and purchase agreement and accounted it as a secured advance. The resale and repurchase agreements can have the offsetting right only under the trading party’s default, insolvency or bankruptcy, which do not satisfy the offsetting criteria of IAS 32. The Group recorded the collateralized borrowing in borrowings and the secured loans in loans and receivables. The Group under the repurchase agreements has offsetting right only upon the counterparty’s default, insolvency or bankruptcy; thus, the repurchase agreements are applied by the TBMA/ISMA Global Master Repurchase Agreement, which does not satisfy the offsetting criteria of IAS 32. The Group disclosed bonds sold (purchased) under repurchase(resale) agreements as borrowings loan at amortized cost and other financial assets (loans and receivables in previous year).
Derivative assets and others
Net financial assets subject to offsetting enforceable master netting arrangements or similar agreements in statement of financial position [Abstract]
Gross amounts of recognized financial assets	[1]	₩ 2,132,698,000,000		₩ 2,992,476,000,000
Gross amounts of recognized financial assets set off		0		1,710,000,000	[1]
Net amounts of financial assets presented	[1]	2,132,698,000,000		2,990,766,000,000
Receivable spot exchange
Net financial assets subject to offsetting enforceable master netting arrangements or similar agreements in statement of financial position [Abstract]
Gross amounts of recognized financial assets		7,463,097,000,000	[2]	3,767,726,000,000	[3]
Gross amounts of recognized financial assets set off		0		0
Net amounts of financial assets presented		7,463,097,000,000	[2]	3,767,726,000,000	[3]
Derivative financial instruments assets and receivable spot exchange [Member]
Related amounts not set off in the consolidated statement of financial position
Netting agreements and others		8,716,272,000,000		5,787,448,000,000
Cash collateral received		21,543,000,000		174,415,000,000
Net amounts		857,980,000,000		796,629,000,000
Bonds purchased under resale agreements
Net financial assets subject to offsetting enforceable master netting arrangements or similar agreements in statement of financial position [Abstract]
Gross amounts of recognized financial assets		6,999,881,000,000	[2]	16,859,064,000,000	[3]
Gross amounts of recognized financial assets set off		0		0
Net amounts of financial assets presented		6,999,881,000,000	[2]	16,859,064,000,000	[3]
Related amounts not set off in the consolidated statement of financial position
Netting agreements and others		6,999,881,000,000		16,859,064,000,000	[3]
Cash collateral received		0		0
Net amounts		0		0
Domestic exchanges receivable
Net financial assets subject to offsetting enforceable master netting arrangements or similar agreements in statement of financial position [Abstract]
Gross amounts of recognized financial assets	[4]	27,527,610,000,000	[2]	39,050,227,000,000	[3]
Gross amounts of recognized financial assets set off	[4]	27,338,204,000,000	[2]	38,985,354,000,000	[3]
Net amounts of financial assets presented	[4]	189,406,000,000	[2]	64,873,000,000	[3]
Related amounts not set off in the consolidated statement of financial position
Netting agreements and others		0		0
Cash collateral received		0		0
Net amounts	[4]	₩ 189,406,000,000	[2]	₩ 64,873,000,000
[1]	The items include derivatives held for trading, derivatives held for hedging and equity-linked securities.
[2]	The items are included in loan at amortized cost and other financial assets.
[3]	The items are included in loans and receivables.
[4]	Certain financial assets and liabilities are presented as net amounts.

Derecognition and offset of 165

Derecognition and offset of financial instruments_Financial liabilities subject to offset enforceable master netting agreements or similar agreements (Details) - KRW (₩)		6 Months Ended	12 Months Ended
		Jun. 30, 2018	Dec. 31, 2017
Net financial liabilities subject to offsetting enforceable master netting arrangements or similar agreements in statement of financial position [Abstract]
Gross amounts of recognized financial liabilities		₩ 41,313,632,000,000	₩ 47,171,791,000,000
Gross amounts of recognized financial liabilities set off		27,338,204,000,000	38,987,064,000,000
Net amounts of financial liabilities presented		13,975,428,000,000	8,184,727,000,000
Related amounts not set off in the consolidated statement of financial position
Netting agreements and others		12,118,939,000,000	7,163,786,000,000
Cash collateral pledged		208,955,000,000	157,750,000,000
Net amounts		₩ 1,647,534,000,000	₩ 863,191,000,000
Description of rights of setoff associated with financial liabilities subject to enforceable master netting arrangement or similar agreement		The Group possesses both the uncollected domestic exchange receivables and the unpaid domestic exchange payable, which satisfy offsetting criteria of IAS 32. Therefore, the total number of uncollected domestic exchange receivables or unpaid domestic exchange payable has been countervailed with part of unpaid domestic exchange payable or uncollected domestic exchange receivables and has been disclosed in loans at amortized cost and other financial assets (loans and receivables in previous year) or other financial liabilities of the Group’s statements of financial position. The Group possesses the derivative assets, derivative liabilities, receivable spot exchange and payable spot exchange that do not satisfy the offsetting criteria of IAS 32, but provide the Group under the circumstances of the trading party’s defaults, insolvency or bankruptcy, the right of offsetting. Item such as cash collateral cannot satisfy the offsetting criteria of IAS 32, but in accordance with the collateral arrangements and under the circumstances of the trading party’s default, insolvency or bankruptcy, the net amount of derivative assets and derivative liabilities, receivable spot exchange and payable spot exchange can be offset. The Group has entered into a resale and repurchase agreement and accounted it as a collateralized borrowing. The Group has also entered into a resale and purchase agreement and accounted it as a secured advance. The resale and repurchase agreements can have the offsetting right only under the trading party’s default, insolvency or bankruptcy, which do not satisfy the offsetting criteria of IAS 32. The Group recorded the collateralized borrowing in borrowings and the secured loans in loans and receivables. The Group under the repurchase agreements has offsetting right only upon the counterparty’s default, insolvency or bankruptcy; thus, the repurchase agreements are applied by the TBMA/ISMA Global Master Repurchase Agreement, which does not satisfy the offsetting criteria of IAS 32. The Group disclosed bonds sold (purchased) under repurchase(resale) agreements as borrowings loan at amortized cost and other financial assets (loans and receivables in previous year).	The Group possesses both the uncollected domestic exchange receivables and the unpaid domestic exchange payable, which satisfy offsetting criteria of IAS 32. Therefore, the total number of uncollected domestic exchange receivables or unpaid domestic exchange payable has been countervailed with part of unpaid domestic exchange payable or uncollected domestic exchange receivables and has been disclosed in loans at amortized cost and other financial assets (loans and receivables in previous year) or other financial liabilities of the Group’s statements of financial position. The Group possesses the derivative assets, derivative liabilities, receivable spot exchange and payable spot exchange that do not satisfy the offsetting criteria of IAS 32, but provide the Group under the circumstances of the trading party’s defaults, insolvency or bankruptcy, the right of offsetting. Item such as cash collateral cannot satisfy the offsetting criteria of IAS 32, but in accordance with the collateral arrangements and under the circumstances of the trading party’s default, insolvency or bankruptcy, the net amount of derivative assets and derivative liabilities, receivable spot exchange and payable spot exchange can be offset. The Group has entered into a resale and repurchase agreement and accounted it as a collateralized borrowing. The Group has also entered into a resale and purchase agreement and accounted it as a secured advance. The resale and repurchase agreements can have the offsetting right only under the trading party’s default, insolvency or bankruptcy, which do not satisfy the offsetting criteria of IAS 32. The Group recorded the collateralized borrowing in borrowings and the secured loans in loans and receivables. The Group under the repurchase agreements has offsetting right only upon the counterparty’s default, insolvency or bankruptcy; thus, the repurchase agreements are applied by the TBMA/ISMA Global Master Repurchase Agreement, which does not satisfy the offsetting criteria of IAS 32. The Group disclosed bonds sold (purchased) under repurchase(resale) agreements as borrowings loan at amortized cost and other financial assets (loans and receivables in previous year).
Derivative liabilities and others
Net financial liabilities subject to offsetting enforceable master netting arrangements or similar agreements in statement of financial position [Abstract]
Gross amounts of recognized financial liabilities	[1]	₩ 2,305,516,000,000	₩ 3,160,217,000,000
Gross amounts of recognized financial liabilities set off		0	1,710,000,000	[1]
Net amounts of financial liabilities presented	[1]	2,305,516,000,000	3,158,507,000,000
Payable spot exchange
Net financial liabilities subject to offsetting enforceable master netting arrangements or similar agreements in statement of financial position [Abstract]
Gross amounts of recognized financial liabilities	[2]	7,464,679,000,000	3,723,886,000,000
Gross amounts of recognized financial liabilities set off		0	0
Net amounts of financial liabilities presented	[2]	7,464,679,000,000	3,723,886,000,000
Derivative financial instruments liabilities and payable spot exchange [Member]
Related amounts not set off in the consolidated statement of financial position
Netting agreements and others		8,704,614,000,000	5,866,682,000,000
Cash collateral pledged		208,955,000,000	157,750,000,000
Net amounts		856,626,000,000	857,961,000,000
Bonds sold under repurchase agreements
Net financial liabilities subject to offsetting enforceable master netting arrangements or similar agreements in statement of financial position [Abstract]
Gross amounts of recognized financial liabilities	[3]	5,372,000,000	3,173,000,000
Gross amounts of recognized financial liabilities set off		0	0
Net amounts of financial liabilities presented	[3]	5,372,000,000	3,173,000,000
Related amounts not set off in the consolidated statement of financial position
Netting agreements and others	[3]	5,372,000,000	3,173,000,000
Cash collateral pledged		0	0
Net amounts		0	0
Domestic exchange payable
Net financial liabilities subject to offsetting enforceable master netting arrangements or similar agreements in statement of financial position [Abstract]
Gross amounts of recognized financial liabilities	[2],[4]	31,538,065,000,000	40,284,515,000,000
Gross amounts of recognized financial liabilities set off	[2],[4]	27,338,204,000,000	38,985,354,000,000
Net amounts of financial liabilities presented	[2],[4]	4,199,861,000,000	1,299,161,000,000
Related amounts not set off in the consolidated statement of financial position
Netting agreements and others	[2],[4]	3,408,953,000,000	1,293,931,000,000
Cash collateral pledged		0	0
Net amounts	[2],[4]	₩ 790,908,000,000	₩ 5,230,000,000
[1]	The items include derivatives held for trading, derivatives held for hedging and equity-linked securities.
[2]	The items are included in other financial liabilities
[3]	The items are included in borrowings.
[4]	Certain financial assets and liabilities are presented as net amounts.

Investment in joint ventures166

Investment in joint ventures and associates_Investments in joint ventures and associates accounted for using the equity method of accounting (Details) - KRW (₩)		6 Months Ended		12 Months Ended
		Jun. 30, 2018		Dec. 31, 2017
Disclosure of investments in associates and joint ventures [Line Items]
Description of reasons why presumption that interest of more than twenty per cent in associate is overcome	[1]	Even though the Group’s ownership interest of the entity is more than 20%, the Group does not have significant influence over the entity since it is going through work-out process under receivership, thus it is excluded from the investment in associates.		Even though the Group’s ownership interest of the entity is more than 20%, the Group does not have significant influence over the entity since it is going through work-out process under receivership, thus it is excluded from the investment in associates.
Kumho Tire Co Inc
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Manufacturing		Manufacturing
Proportion of ownership interest in associates and joint ventures		14.20%		14.20%
Financial statements as of June 30 2018		Mar. 31, 2018
Description of reason why using different reporting date or period for associate	[2]	The significant transactions and events between the end of reporting period of the associates and the Group have been properly incorporated.
Description of nature of entitys relationship with associate	[3],[4]	The Group has significant influence on these entities through its position in the creditors' council which is the decision making body regarding to financial and operational policies of associates. The investments in associates that have quoted market prices are Kumho Tire Co., Ltd. , Chin Hung International Inc. .		The Group has significant influence on these entities through its position in the creditors' council which is the decision making body regarding to financial and operational policies of associates. The investments in associates that have quoted market prices are Kumho Tire Co., Ltd. , Chin Hung International Inc. .
Fair value of investments in associates for which there are quoted market prices	[4]	₩ 6,310		₩ 4,425
Woori Service Networks Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Freight & staffing services		Freight & staffing services
Proportion of ownership interest in associates and joint ventures		4.90%		4.90%
Financial statements as of June 30 2018		May 31, 2018
Description of reason why using different reporting date or period for associate	[2]	The significant transactions and events between the end of reporting period of the associates and the Group have been properly incorporated.
Description of nature of entitys relationship with associate	[5]	Most of the significant business transactions of associates are with the Group as of June 30, 2018 and December 31, 2017.		Most of the significant business transactions of associates are with the Group as of June 30, 2018 and December 31, 2017.
Korea Credit Bureau Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Credit information		Credit information
Proportion of ownership interest in associates and joint ventures		9.90%		9.90%
Financial statements as of June 30 2018		Jun. 30, 2018
Description of nature of entitys relationship with associate	[6]	The Group can participate in decision-making body and exercise significant influence over associates through business partnerships.		The Group can participate in decision-making body and exercise significant influence over associates through business partnerships.
Korea Finance Security Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Security service		Security service
Proportion of ownership interest in associates and joint ventures		15.00%		15.00%
Financial statements as of June 30 2018		May 31, 2018
Description of reason why using different reporting date or period for associate	[2]	The significant transactions and events between the end of reporting period of the associates and the Group have been properly incorporated.
Description of nature of entitys relationship with associate	[5]	Most of the significant business transactions of associates are with the Group as of June 30, 2018 and December 31, 2017.		Most of the significant business transactions of associates are with the Group as of June 30, 2018 and December 31, 2017.
Chin Hung International Inc
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Construction		Construction
Proportion of ownership interest in associates and joint ventures		25.30%		25.30%
Financial statements as of June 30 2018		May 31, 2018
Description of reason why using different reporting date or period for associate	[2]	The significant transactions and events between the end of reporting period of the associates and the Group have been properly incorporated.
Description of nature of entitys relationship with associate	[4]	The investments in associates that have quoted market prices are Kumho Tire Co., Ltd. , Chin Hung International Inc. .		The investments in associates that have quoted market prices are Kumho Tire Co., Ltd. , Chin Hung International Inc. .
Fair value of investments in associates for which there are quoted market prices	[4]	₩ 1,935		₩ 1,915
Poonglim Industrial Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Construction		Construction
Proportion of ownership interest in associates and joint ventures				29.40%
Description of reasons why presumption that interest of more than twenty per cent in associate is overcome	[7]	The Group does not have significant influence over the entity since it is going through work-out process under receivership, thus it is excluded from the investment in associates for the six months ended June 30, 2018.
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
STX Engine Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Manufacturing		Manufacturing
Proportion of ownership interest in associates and joint ventures				29.20%
Description of nature of entitys relationship with associate	[9]	The entity was sold after it was transferred to assets held for sale for the year ended June 30, 2018.
STX Corporation
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Wholesale of non-specialized goods		Wholesale of non-specialized goods
Proportion of ownership interest in associates and joint ventures		19.70%		19.70%
Financial statements as of June 30 2018		May 31, 2018
Description of reason why using different reporting date or period for associate	[2]	The significant transactions and events between the end of reporting period of the associates and the Group have been properly incorporated.
Description of nature of entitys relationship with associate	[3]	The Group has significant influence on these entities through its position in the creditors' council which is the decision making body regarding to financial and operational policies of associates. The shares of STX Corporation owned by the Group were reclassified as assets held for sale, as the creditor financial institutions committee entered into a contract with AFC Korea Co., Ltd. during the previous year to sell STX Corporation shares.	[4]	The Group has significant influence on these entities through its position in the creditors' council which is the decision making body regarding to financial and operational policies of associates.
Saman Corporation
Disclosure of investments in associates and joint ventures [Line Items]
Main business		General construction Technology service		General construction Technology service
Proportion of ownership interest in associates and joint ventures		9.20%		9.20%
Financial statements as of June 30 2018		May 31, 2018
Description of reason why using different reporting date or period for associate	[2]	The significant transactions and events between the end of reporting period of the associates and the Group have been properly incorporated.
Description of nature of entitys relationship with associate	[6]	The Group can participate in decision-making body and exercise significant influence over associates through business partnerships.		The Group can participate in decision-making body and exercise significant influence over associates through business partnerships.
Dongwoo C and C Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Construction		Construction
Proportion of ownership interest in associates and joint ventures		23.20%		23.20%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
SJCO Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Aggregate transportation and wholesale		Aggregate transportation and wholesale
Proportion of ownership interest in associates and joint ventures		26.50%		26.50%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
G2 Collection Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Wholesale and retail sales		Wholesale and retail sales
Proportion of ownership interest in associates and joint ventures		28.90%		28.90%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
The Base Enterprise Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Manufacturing		Manufacturing
Proportion of ownership interest in associates and joint ventures		48.40%		48.40%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
Kyesan engineering Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Construction		Construction
Proportion of ownership interest in associates and joint ventures		23.20%		23.20%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
Good software lab Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Service		Service
Proportion of ownership interest in associates and joint ventures		28.90%		28.90%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
Wongwang Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Wholesale and real estate		Wholesale and real estate
Proportion of ownership interest in associates and joint ventures		29.00%		29.00%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
Sejin construction Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Construction		Construction
Proportion of ownership interest in associates and joint ventures		29.60%		29.60%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
QTS shipping Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Composite transportation Arrangement		Composite transportation Arrangement
Proportion of ownership interest in associates and joint ventures		49.40%		49.40%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
DAEA SNC Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Wholesale and retail sales		Wholesale and retail sales
Proportion of ownership interest in associates and joint ventures		24.00%		24.00%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
ARES TECH Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Electronic component manufacturing		Electronic component manufacturing
Proportion of ownership interest in associates and joint ventures		23.40%		23.40%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
Reading Doctors Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Other service business		Other service business
Proportion of ownership interest in associates and joint ventures		35.40%		35.40%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
PREXCO Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Manufacturing		Manufacturing
Proportion of ownership interest in associates and joint ventures		28.10%		28.10%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
Hyunwoo International Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Manufacturing		Manufacturing
Proportion of ownership interest in associates and joint ventures		25.90%		25.90%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
Jiwon Plating Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Plating		Plating
Proportion of ownership interest in associates and joint ventures		20.50%		20.50%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
Cultizm Korea LTD Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Wholesale and retail sales		Wholesale and retail sales
Proportion of ownership interest in associates and joint ventures		31.30%		31.30%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
Gil Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Manufacturing		Manufacturing
Proportion of ownership interest in associates and joint ventures		26.10%		26.10%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
Nk Eng Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Manufacturing		Manufacturing
Proportion of ownership interest in associates and joint ventures		23.10%		23.10%
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
Youngdong Sea Food Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Processed sea food manufacturing		Processed sea food manufacturing
Proportion of ownership interest in associates and joint ventures		24.00%
Description of reasons why presumption that interest of more than twenty per cent in associate is overcome	[10]			As of December 31, 2017, the ownership ratio of the common stocks was more than 20%, but the entity was excluded from investments in associates because it has been under rehabilitation and not able to exercise significant influence. However, as of June 30, 2018, it was included in investments in associates by finalizing rehabilitation process by the court administration.
Description of nature of entitys relationship with associate	[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017. As of December 31, 2017, the ownership ratio of the common stocks was more than 20%, but the entity was excluded from investments in associates because it has been under rehabilitation and not able to exercise significant influence. However, as of June 30, 2018, it was included in investments in associates by finalizing rehabilitation process by the court administration.		The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
Woori Growth Partnerships New Technology Private Equity Fund
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Other financial business		Other financial business
Proportion of ownership interest in associates and joint ventures		23.10%		23.10%
Financial statements as of June 30 2018		Jun. 30, 2018
2016KIF-IMM Woori Bank Technology Venture Fund
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Other financial business		Other financial business
Proportion of ownership interest in associates and joint ventures		20.00%		20.00%
Financial statements as of June 30 2018		Jun. 30, 2018
K BANK Co Ltd
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Finance		Finance
Proportion of ownership interest in associates and joint ventures		13.00%		13.00%
Financial statements as of June 30 2018		May 31, 2018
Description of reason why using different reporting date or period for associate	[2]	The significant transactions and events between the end of reporting period of the associates and the Group have been properly incorporated.
Description of nature of entitys relationship with associate	[6]	The Group can participate in decision-making body and exercise significant influence over associates through business partnerships.		The Group can participate in decision-making body and exercise significant influence over associates through business partnerships.
Smart Private Equity Fund No.2
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Other financial business		Other financial business
Proportion of ownership interest in associates and joint ventures		20.00%		20.00%
Financial statements as of June 30 2018		Jun. 30, 2018
Woori Bank-Company K Korea Movie Asset Fund
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Other financial business		Other financial business
Proportion of ownership interest in associates and joint ventures		25.00%		25.00%
Financial statements as of June 30 2018		Jun. 30, 2018
Well to Sea No.3 Private Equity Fund
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Finance		Finance
Proportion of ownership interest in associates and joint ventures		50.00%		50.00%
Financial statements as of June 30 2018		Mar. 31, 2018
Description of reason why using different reporting date or period for associate	[2]	The significant transactions and events between the end of reporting period of the associates and the Group have been properly incorporated.
Description of nature of entitys relationship with associate	[11]	The Bank has entered into a contract whereas the Bank (or a third party designated by the Bank) obtains a preemptive right to acquire the base assets (Aju Capital Co. Ltd.) of Well to Sea No. 3 Private Equity Fund, an affiliate of the Bank, when the Fund disposes them.		The Bank has entered into a contract whereas the Bank (or a third party designated by the Bank) obtains a preemptive right to acquire the base assets (Aju Capital Co. Ltd.) of Well to Sea No. 3 Private Equity Fund, an affiliate of the Bank, when the Fund disposes them.
Partner one Value Up I Private Equity Fund
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Other financial business		Other financial business
Proportion of ownership interest in associates and joint ventures		23.30%
Financial statements as of June 30 2018		Jun. 30, 2018
Description of nature of entitys relationship with associate	[12]	Due to capital contribution by the Group for the six months ended June 30, 2018, the entities has been included in the investment in associates.
IBK KIP Seongjang Dideemdol 1st Private Investment Limited Partnership
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Other Finance business		Other Finance business
Proportion of ownership interest in associates and joint ventures		20.00%
Financial statements as of June 30 2018		Jun. 30, 2018
Description of nature of entitys relationship with associate	[12]	Due to capital contribution by the Group for the six months ended June 30, 2018, the entities has been included in the investment in associates.
Nomura-Rifa Private Real Estate Investment Trust No.17
Disclosure of investments in associates and joint ventures [Line Items]
Main business		Other financial business		Other financial business
Proportion of ownership interest in associates and joint ventures		21.90%		25.00%
Financial statements as of June 30 2018		Jun. 30, 2018
[1]	Even though the Group’s ownership interest of the entity is more than 20%, the Group does not have significant influence over the entity since it is going through work-out process under receivership, thus it is excluded from the investment in associates.
[2]	The significant transactions and events between the end of reporting period of the associates and the Group have been properly incorporated.
[3]	The Group has significant influence on these entities through its position in the creditors' council which is the decision making body regarding to financial and operational policies of associates.
[4]	The investments in associates that have quoted market prices are Kumho Tire Co., Ltd. (current period: KRW 6,310, previous year: KRW 4,425), Chin Hung International Inc. (current period: KRW 1,935, previous year: KRW 1,915).
[5]	Most of the significant business transactions of associates are with the Group as of June 30, 2018 and December 31, 2017.
[6]	The Group can participate in decision-making body and exercise significant influence over associates through business partnerships.
[7]	The Group does not have significant influence over the entity since it is going through work-out process under receivership, thus it is excluded from the investment in associates for the six months ended June 30, 2018.
[8]	The carrying values of investments in associates are nil as of June 30, 2018 and December 31, 2017.
[9]	The entity was sold after it was transferred to assets held for sale for the year ended June 30, 2018.
[10]	As of December 31, 2017, the ownership ratio of the common stocks was more than 20%, but the entity was excluded from investments in associates because it has been under rehabilitation and not able to exercise significant influence. However, as of June 30, 2018, it was included in investments in associates by finalizing rehabilitation process by the court administration.
[11]	The Bank has entered into a contract whereas the Bank (or a third party designated by the Bank) obtains a preemptive right to acquire the base assets (Aju Capital Co. Ltd.) of Well to Sea No. 3 Private Equity Fund, an affiliate of the Bank, when the Fund disposes them.
[12]	Due to capital contribution by the Group for the six months ended June 30, 2018, the entities has been included in the investment in associates.

Investment in joint ventures167

Investment in joint ventures and associates_Changes in the carrying value of investments in joint ventures and associates accounted for using the equity method of accounting (Details) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2018KRW (₩)		Jun. 30, 2017KRW (₩)		Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					₩ 417,051,000,000			₩ 439,012,000,000
Acquisition cost	₩ 589,641,000,000		₩ 558,529,000,000		589,641,000,000			558,529,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)	7,681,000,000		(14,863,000,000)		(1,462,000,000)			(58,955,000,000)
Acquisition					20,048,000,000			63,084,000,000
Disposal and others					(9,719,000,000)			(16,852,000,000)
Dividends					(651,000,000)			(57,320,000,000)
Change in capital					(12,327,000,000)			2,038,000,000
Others								(208,000,000)
Ending	412,940,000,000		370,799,000,000		412,940,000,000		$ 371,416	370,799,000,000
Changes in investments in associates due to accounts transfer	(5,865,000,000)	[1]	(16,354,000,000)	[2]	(5,865,000,000)	[1]		(16,354,000,000)	[2]
Changes in investments in associates due to equity swap	0		51,405,000,000	[3]	0			51,405,000,000	[3]
Woori Blackstone Korea Opportunity No.1 Private Equity Fund
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning								15,289,000,000
Acquisition cost			6,881,000,000					6,881,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)								(1,460,000,000)
Acquisition								0
Disposal and others								0
Dividends								0
Change in capital								0
Others								0
Ending			13,829,000,000					13,829,000,000
Kumho Tire Co Inc
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					98,933,000,000			200,332,000,000
Acquisition cost	175,652,000,000		175,652,000,000		175,652,000,000			175,652,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					(10,451,000,000)			2,000,000
Acquisition					0			0
Disposal and others					0			0
Dividends					0			0
Change in capital					(5,196,000,000)			(1,623,000,000)
Others								0
Ending	83,286,000,000		198,711,000,000		83,286,000,000			198,711,000,000
Woori Service Networks Co Ltd
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					158,000,000			145,000,000
Acquisition cost	108,000,000		108,000,000		108,000,000			108,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					(20,000,000)			(10,000,000)
Acquisition					0			0
Disposal and others					0			0
Dividends					0			(8,000,000)
Change in capital					0			0
Others								0
Ending	138,000,000		127,000,000		138,000,000			127,000,000
Korea Credit Bureau Co Ltd
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					5,816,000,000			5,592,000,000
Acquisition cost	3,313,000,000		3,313,000,000		3,313,000,000			3,313,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					692,000,000			508,000,000
Acquisition					0			0
Disposal and others					0			0
Dividends					(113,000,000)			(149,000,000)
Change in capital					0			0
Others								0
Ending	6,395,000,000		5,951,000,000		6,395,000,000			5,951,000,000
Korea Finance Security Co Ltd
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					3,519,000,000			3,376,000,000
Acquisition cost	3,267,000,000		3,266,000,000		3,267,000,000			3,266,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					4,000,000			63,000,000
Acquisition					0			0
Disposal and others					0			0
Dividends					(54,000,000)			(54,000,000)
Change in capital					1,000,000			0
Others								0
Ending	3,470,000,000		3,385,000,000		3,470,000,000			3,385,000,000
Chin Hung International Inc
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					45,101,000,000			43,032,000,000
Acquisition cost	130,779,000,000		89,725,000,000		130,779,000,000			89,725,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					3,179,000,000			(20,050,000,000)
Acquisition					0			41,053,000,000
Disposal and others					0			0
Dividends								0
Change in capital					(484,000,000)			171,000,000
Others								(25,966,000,000)
Ending	47,796,000,000		38,240,000,000		47,796,000,000			38,240,000,000
Poonglim Industrial Co Ltd
Disclosure of changes in investments in associates and joint ventures [Line Items]
Acquisition cost	13,916,000,000		13,916,000,000		13,916,000,000			13,916,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					0			0
Acquisition					0			0
Disposal and others					0			0
Dividends					0			0
Change in capital					0			0
Others								0
Ending	0		0		0			0
STX Engine Co Ltd
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning								43,036,000,000
Acquisition cost			92,038,000,000					92,038,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)								722,000,000
Acquisition								0
Disposal and others								0
Dividends								0
Change in capital								4,047,000,000
Others								0
Ending			47,805,000,000					47,805,000,000
Samho Co Ltd
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning								19,729,000,000
Acquisition cost			7,492,000,000					7,492,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)								2,021,000,000
Acquisition								0
Disposal and others								(16,354,000,000)
Dividends								0
Change in capital								(73,000,000)
Others								(5,323,000,000)
Ending			0					0
STX Corporation
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					6,947,000,000
Acquisition cost	50,760,000,000		42,215,000,000		50,760,000,000			42,215,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					(816,000,000)			(33,739,000,000)
Acquisition					0			8,546,000,000
Disposal and others					(5,865,000,000)			0
Dividends								0
Change in capital					(266,000,000)			(215,000,000)
Others								27,772,000,000
Ending			2,364,000,000					2,364,000,000
Saman Corporation
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					1,254,000,000			8,699,000,000
Acquisition cost	8,521,000,000		8,521,000,000		8,521,000,000			8,521,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					(48,000,000)			(96,000,000)
Acquisition					0			0
Disposal and others					0			0
Dividends								0
Change in capital					34,000,000			26,000,000
Others								0
Ending	1,240,000,000		8,629,000,000		1,240,000,000			8,629,000,000
Woori Growth Partnerships New Technology Private Equity Fund
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					27,611,000,000			13,118,000,000
Acquisition cost	28,833,000,000		13,602,000,000		28,833,000,000			13,602,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					1,139,000,000			(371,000,000)
Acquisition					0			5,745,000,000
Disposal and others					(3,346,000,000)			(498,000,000)
Dividends					(484,000,000)			0
Change in capital					0			(156,000,000)
Others								0
Ending	24,920,000,000		17,838,000,000		24,920,000,000			17,838,000,000
2016KIF-IMM Woori Bank Technology Venture Fund
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					6,840,000,000			1,800,000,000
Acquisition cost	6,840,000,000		1,800,000,000		6,840,000,000			1,800,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					0			0
Acquisition					6,780,000,000			3,240,000,000
Disposal and others					0			0
Dividends					0			0
Change in capital					0			0
Others								0
Ending	13,620,000,000		5,040,000,000		13,620,000,000			5,040,000,000
K BANK Co Ltd
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					31,735,000,000			30,442,000,000
Acquisition cost	45,392,000,000		32,500,000,000		45,392,000,000			32,500,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					(5,384,000,000)			(5,861,000,000)
Acquisition					0			0
Disposal and others					0			0
Dividends					0			0
Change in capital					7,000,000			(139,000,000)
Others								0
Ending	26,358,000,000		24,442,000,000		26,358,000,000			24,442,000,000
Smart Private Equity Fund No.2
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					2,932,000,000
Acquisition cost	3,000,000,000		3,000,000,000		3,000,000,000			3,000,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					(21,000,000)			(47,000,000)
Acquisition					0			3,000,000,000
Disposal and others					0			0
Dividends					0			0
Change in capital					0			0
Others								0
Ending	2,911,000,000		2,953,000,000		2,911,000,000			2,953,000,000
Woori Bank-Company K Korea Movie Asset Fund
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					2,957,000,000
Acquisition cost	3,000,000,000		1,500,000,000		3,000,000,000			1,500,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					10,000,000			(15,000,000)
Acquisition					0			1,500,000,000
Disposal and others					0			0
Dividends					0			0
Change in capital					0			0
Others								0
Ending	2,967,000,000		1,485,000,000		2,967,000,000			1,485,000,000
Well to Sea No.3 Private Equity Fund
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					182,309,000,000
Acquisition cost	101,992,000,000				101,992,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					10,321,000,000
Acquisition					0
Disposal and others					(508,000,000)
Dividends					0
Change in capital					(6,423,000,000)
Ending	185,699,000,000				185,699,000,000
Partner one Value Up I Private Equity Fund
Disclosure of changes in investments in associates and joint ventures [Line Items]
Acquisition cost	10,000,000,000				10,000,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					(13,000,000)
Acquisition					10,000,000,000
Disposal and others					0
Dividends					0
Change in capital					0
Ending	9,987,000,000				9,987,000,000
IBK KIP Seongjang Dideemdol 1st Private Investment Limited Partnership
Disclosure of changes in investments in associates and joint ventures [Line Items]
Acquisition cost	3,268,000,000				3,268,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					0
Acquisition					3,268,000,000
Disposal and others					0
Dividends					0
Change in capital					0
Ending	3,268,000,000				3,268,000,000
Woori Renaissance Holdings
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning								54,422,000,000
Acquisition cost			₩ 63,000,000,000					63,000,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)								(622,000,000)
Acquisition								0
Disposal and others								0
Dividends								(57,109,000,000)
Change in capital								0
Others								₩ 3,309,000,000
Nomura-Rifa Private Real Estate Investment Trust No.17
Disclosure of changes in investments in associates and joint ventures [Line Items]
Beginning					939,000,000
Acquisition cost	1,000,000,000				1,000,000,000
Changes in investments in associates and joint ventures [Abstract]
Share of profits(losses)					(54,000,000)
Acquisition					0
Disposal and others					0
Dividends					0
Change in capital					0
Ending	₩ 885,000,000				₩ 885,000,000
[1]	Investments in joint ventures and associates decreased by 5,865 million Won through transfers to assets held for sale which occurred during the six months ended June 30, 2018.
[2]	Investments in joint ventures and associates decreased by 16,354 million Won through transfers to assets held for sale occurred for the six months ended June 30, 2017.
[3]	Changes in investments in joint ventures and associates due to debt-equity swap is 51,405 million Won.

Investment In Joint Ventures168

Investment In Joint Ventures And Associates_Financial information relating to investments in joint ventures and associates accounted for using the equity method of accounting (Details) - KRW (₩) ₩ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Kumho Tire Co Inc
Equity method investment summarized financial information [Line Items]
Assets	₩ 4,513,972	₩ 5,105,107
Liabilities	3,521,608	3,928,327
Operating revenue	624,981	2,136,569
Net income(loss)	(10,774)	(61,748)
Woori Service Networks Co Ltd
Equity method investment summarized financial information [Line Items]
Assets	4,909	4,982
Liabilities	2,111	1,780
Operating revenue	7,250	14,887
Net income(loss)	456	1,003
Korea Credit Bureau Co Ltd
Equity method investment summarized financial information [Line Items]
Assets	80,792	75,504
Liabilities	18,764	19,323
Operating revenue	37,342	68,750
Net income(loss)	5,919	3,580
Korea Finance Security Co Ltd
Equity method investment summarized financial information [Line Items]
Assets	32,635	33,915
Liabilities	9,501	10,461
Operating revenue	27,161	55,610
Net income(loss)	91	1,071
Chin Hung International Inc
Equity method investment summarized financial information [Line Items]
Assets	403,962	341,284
Liabilities	311,502	259,454
Operating revenue	263,861	513,285
Net income(loss)	19,062	28,698
Poonglim Industrial Co Ltd
Equity method investment summarized financial information [Line Items]
Assets		241,063
Liabilities		309,925
Operating revenue		107,360
Net income(loss)		(29,812)
STX Corporation
Equity method investment summarized financial information [Line Items]
Assets		595,348
Liabilities		543,458
Operating revenue		1,371,272
Net income(loss)		342,869
Saman Corporation
Equity method investment summarized financial information [Line Items]
Assets	89,932	98,435
Liabilities	61,583	69,929
Operating revenue	26,418	76,135
Net income(loss)	(326)	(6,096)
Woori Growth Partnerships New Technology Private Equity Fund
Equity method investment summarized financial information [Line Items]
Assets	108,427	120,133
Liabilities	441	485
Operating revenue	7,865	1,024
Net income(loss)	4,936	(3,199)
2016KIF-IMM Woori Bank Technology Venture Fund
Equity method investment summarized financial information [Line Items]
Assets	65,760	32,815
Liabilities	383	380
Operating revenue	6	6
Net income(loss)	(754)	(1,515)
K BANK Co Ltd
Equity method investment summarized financial information [Line Items]
Assets	1,758,930	1,244,270
Liabilities	1,557,206	1,001,121
Operating revenue	24,296	19,231
Net income(loss)	(32,126)	(74,403)
Smart Private Equity Fund No.2
Equity method investment summarized financial information [Line Items]
Assets	14,605	14,711
Liabilities	51	51
Operating revenue	1	1
Net income(loss)	(106)	(340)
Woori Bank-Company K Korea Movie Asset Fund
Equity method investment summarized financial information [Line Items]
Assets	11,872	11,830
Liabilities	3	2
Operating revenue	893	16
Net income(loss)	769	(172)
Well to Sea No.3 Private Equity Fund
Equity method investment summarized financial information [Line Items]
Assets	5,297,764	5,068,424
Liabilities	4,759,158	4,534,957
Operating revenue	140,041	131,488
Net income(loss)	13,450	162,743
Partner one Value Up I Private Equity Fund
Equity method investment summarized financial information [Line Items]
Assets	43,114
Liabilities	172
Operating revenue	114
Net income(loss)	(58)
IBK KIP Seongjang Dideemdol 1st Private Investment Limited Partnership
Equity method investment summarized financial information [Line Items]
Assets	15,843
Liabilities	744
Operating revenue	4
Net income(loss)	(822)
Nomura-Rifa Private Real Estate Investment Trust No.17
Equity method investment summarized financial information [Line Items]
Assets	20,433	20,265
Liabilities	16,407	16,507
Operating revenue	56	62
Net income(loss)	₩ (55)	₩ (242)

Investment in joint ventures169

Investment in joint ventures and associates_Entities not applied for equity method of accounting with ownership ratio exceeding twenty percent (Details) - shares		6 Months Ended	12 Months Ended
		Jun. 30, 2018	Dec. 31, 2017
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Description of reasons why presumption that interest of more than twenty per cent in associate is overcome	[1]	Even though the Group’s ownership interest of the entity is more than 20%, the Group does not have significant influence over the entity since it is going through work-out process under receivership, thus it is excluded from the investment in associates.	Even though the Group’s ownership interest of the entity is more than 20%, the Group does not have significant influence over the entity since it is going through work-out process under receivership, thus it is excluded from the investment in associates.
Poonglim Industrial Co Ltd
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned		4,142,782
Ownership	[1]	29.10%
Description of reasons why presumption that interest of more than twenty per cent in associate is overcome	[2]	The Group does not have significant influence over the entity since it is going through work-out process under receivership, thus it is excluded from the investment in associates for the six months ended June 30, 2018.
Orient Shipyard Co Ltd
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned		464,812	465,050
Ownership	[1]	21.40%	21.40%
Saenuel Co Ltd
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned		3,531	3,531
Ownership	[1]	37.40%	37.40%
E mirae Tech Co Ltd
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned		7,696	7,696
Ownership	[1]	41.00%	41.00%
Jehin Trading Co Ltd
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned		81,610	81,610
Ownership	[1]	27.30%	27.30%
The season Co Ltd
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned		18,187	18,187
Ownership	[1]	30.10%	30.10%
Yuil PESC Co Ltd
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned		8,642	8,642
Ownership	[1]	24.00%	24.00%
Youngdong Sea Food Co Ltd
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned			12,106
Ownership	[1]		24.00%
Description of reasons why presumption that interest of more than twenty per cent in associate is overcome	[3]		As of December 31, 2017, the ownership ratio of the common stocks was more than 20%, but the entity was excluded from investments in associates because it has been under rehabilitation and not able to exercise significant influence. However, as of June 30, 2018, it was included in investments in associates by finalizing rehabilitation process by the court administration.
Sinseong Trading Co Ltd
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned		2,584	2,584
Ownership	[1]	27.20%	27.20%
CL Tech Co Ltd
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned		13,759	13,759
Ownership	[1]	38.60%	38.60%
Force tec Co Ltd [Member]
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned		4,780,907	4,780,907
Ownership	[1]	25.80%	25.80%
Protronics Co Ltd
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned		95,921	95,921
Ownership	[1]	48.10%	48.10%
Instern Co Ltd
Disclosure of entities not applied for equity method of accounting with ownership ratio exceeding twenty percent [Line Items]
Number of shares owned		14,296	14,296
Ownership	[1]	20.10%	20.10%
[1]	Even though the Group’s ownership interest of the entity is more than 20%, the Group does not have significant influence over the entity since it is going through work-out process under receivership, thus it is excluded from the investment in associates.
[2]	The Group does not have significant influence over the entity since it is going through work-out process under receivership, thus it is excluded from the investment in associates for the six months ended June 30, 2018.
[3]	As of December 31, 2017, the ownership ratio of the common stocks was more than 20%, but the entity was excluded from investments in associates because it has been under rehabilitation and not able to exercise significant influence. However, as of June 30, 2018, it was included in investments in associates by finalizing rehabilitation process by the court administration.

Investment in joint ventures170

Investment in joint ventures and associates_Reconciliations from the net assets of associates based on the ownership ratio to corresponding book value of investment in joint ventures and associates (Details) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2018KRW (₩)	Dec. 31, 2017KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)	Dec. 31, 2016KRW (₩)
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Book value		₩ 412,940,000,000	₩ 417,051,000,000	$ 371,416	₩ 370,799,000,000	₩ 439,012,000,000
Kumho Tire Co Inc
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset	[1]	₩ 954,857,000,000	₩ 1,065,421,000,000
Ownership		14.20%	14.20%
Net assets of associates(or joint ventures)		₩ 135,122,000,000	₩ 150,767,000,000
Cost-book value differential		48,459,000,000	48,459,000,000
Impairment		(102,843,000,000)	(102,843,000,000)
Intercompany transaction and others		2,548,000,000	2,549,000,000
Book value		83,286,000,000	98,933,000,000		198,711,000,000	200,332,000,000
Woori Service Networks Co Ltd
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset		₩ 2,798,000,000	₩ 3,202,000,000
Ownership		4.90%	4.90%
Net assets of associates(or joint ventures)		₩ 138,000,000	₩ 158,000,000
Cost-book value differential		0	0
Impairment		0	0
Intercompany transaction and others		0	0
Book value		138,000,000	158,000,000		127,000,000	145,000,000
Korea Credit Bureau Co Ltd
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset		₩ 62,028,000,000	₩ 56,181,000,000
Ownership		9.90%	9.90%
Net assets of associates(or joint ventures)		₩ 6,149,000,000	₩ 5,568,000,000
Cost-book value differential		246,000,000	248,000,000
Impairment		0	0
Intercompany transaction and others		0	0
Book value		6,395,000,000	5,816,000,000		5,951,000,000	5,592,000,000
Korea Finance Security Co Ltd
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset		₩ 23,134,000,000	₩ 23,454,000,000
Ownership		15.00%	15.00%
Net assets of associates(or joint ventures)		₩ 3,470,000,000	₩ 3,519,000,000
Cost-book value differential		0	0
Impairment		0	0
Intercompany transaction and others		0	0
Book value		3,470,000,000	3,519,000,000		3,385,000,000	3,376,000,000
Chin Hung International Inc
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset	[1]	₩ 92,316,000,000	₩ 81,686,000,000
Ownership		25.30%	25.30%
Net assets of associates(or joint ventures)		₩ 23,361,000,000	₩ 20,671,000,000
Cost-book value differential		24,565,000,000	24,565,000,000
Impairment		0	0
Intercompany transaction and others		(130,000,000)	(136,000,000)
Book value		47,796,000,000	45,101,000,000		38,240,000,000	43,032,000,000
Poonglim Industrial Co Ltd
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset	[1]		₩ (168,154,000,000)
Ownership			29.40%
Net assets of associates(or joint ventures)			₩ (49,446,000,000)
Cost-book value differential			54,542,000,000
Impairment			(20,504,000,000)
Intercompany transaction and others			15,408,000,000
Book value		₩ 0			0
STX Corporation
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset			₩ 51,890,000,000
Ownership		19.70%	19.70%
Net assets of associates(or joint ventures)			₩ 10,232,000,000
Cost-book value differential			24,614,000,000
Impairment			(27,904,000,000)
Intercompany transaction and others			5,000,000
Book value			6,947,000,000		2,364,000,000
Saman Corporation
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset		₩ 28,349,000,000	₩ 28,506,000,000
Ownership		9.20%	9.20%
Net assets of associates(or joint ventures)		₩ 2,605,000,000	₩ 2,619,000,000
Cost-book value differential		5,373,000,000	5,373,000,000
Impairment		(6,738,000,000)	(6,738,000,000)
Intercompany transaction and others		0	0
Book value		1,240,000,000	1,254,000,000		8,629,000,000	8,699,000,000
Woori Growth Partnerships New Technology Private Equity Fund
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset		₩ 107,986,000,000	₩ 119,648,000,000
Ownership		23.10%	23.10%
Net assets of associates(or joint ventures)		₩ 24,920,000,000	₩ 27,611,000,000
Cost-book value differential		0	0
Impairment		0	0
Intercompany transaction and others		0	0
Book value		24,920,000,000	27,611,000,000		17,838,000,000	13,118,000,000
2016KIF-IMM Woori Bank Technology Venture Fund
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset		₩ 65,377,000,000	₩ 32,435,000,000
Ownership		20.00%	20.00%
Net assets of associates(or joint ventures)		₩ 13,075,000,000	₩ 6,487,000,000
Cost-book value differential		0	0
Impairment		0	0
Intercompany transaction and others		545,000,000	353,000,000
Book value		13,620,000,000	6,840,000,000		5,040,000,000	1,800,000,000
K BANK Co Ltd
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset		₩ 201,724,000,000	₩ 243,149,000,000
Ownership		13.00%	13.00%
Net assets of associates(or joint ventures)		₩ 26,162,000,000	₩ 31,535,000,000
Cost-book value differential		0	0
Impairment		0	0
Intercompany transaction and others		196,000,000	200,000,000
Book value		26,358,000,000	31,735,000,000		24,442,000,000	₩ 30,442,000,000
Smart Private Equity Fund No.2
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset		₩ 14,554,000,000	₩ 14,660,000,000
Ownership		20.00%	20.00%
Net assets of associates(or joint ventures)		₩ 2,911,000,000	₩ 2,932,000,000
Cost-book value differential		0	0
Impairment		0	0
Intercompany transaction and others		0	0
Book value		2,911,000,000	2,932,000,000		2,953,000,000
Woori Bank-Company K Korea Movie Asset Fund
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset		₩ 11,869,000,000	₩ 11,828,000,000
Ownership		25.00%	25.00%
Net assets of associates(or joint ventures)		₩ 2,967,000,000	₩ 2,957,000,000
Cost-book value differential		0	0
Impairment		0	0
Intercompany transaction and others		0	0
Book value		2,967,000,000	2,957,000,000		₩ 1,485,000,000
Well to Sea No.3 Private Equity Fund
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset	[1]	₩ 371,813,000,000	₩ 364,909,000,000
Ownership		50.00%	50.00%
Net assets of associates(or joint ventures)		₩ 185,816,000,000	₩ 182,366,000,000
Cost-book value differential		0	0
Impairment		0	0
Intercompany transaction and others		(117,000,000)	(57,000,000)
Book value		185,699,000,000	182,309,000,000
Partner One Value Up I Private Equity Fund [Member]
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset		₩ 42,942,000,000
Ownership		23.30%
Net assets of associates(or joint ventures)		₩ 9,987,000,000
Cost-book value differential		0
Impairment		0
Intercompany transaction and others		0
Book value		9,987,000,000
IBK KIP Seongjang Dideemdol 1st Private Investment Limited Partnership [Member]
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset		₩ 15,099,000,000
Ownership		20.00%
Net assets of associates(or joint ventures)		₩ 3,020,000,000
Cost-book value differential		0
Impairment		0
Intercompany transaction and others		248,000,000
Book value		3,268,000,000
Nomura-Rifa Private Real Estate Investment Trust No.17
Reconciliations from the net assets of associates and joint ventures based on the ownership ratio to corresponding book value of investment in associates and joint ventures [Line Items]
Total net asset		₩ 4,026,000,000	₩ 3,758,000,000
Ownership		21.90%	25.00%
Net assets of associates(or joint ventures)		₩ 882,000,000	₩ 939,000,000
Cost-book value differential		0	0
Impairment		0	0
Intercompany transaction and others		3,000,000	0
Book value		₩ 885,000,000	₩ 939,000,000
[1]	The net asset amount is after reflecting debt-equity swap and others.

Investment properties_Details o

Investment properties_Details of investment properties (Details) $ in Thousands, ₩ in Millions	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)	Jun. 30, 2017KRW (₩)	Dec. 31, 2016KRW (₩)
Disclosure of investment property [Line Items]
Net carrying value	₩ 381,177	$ 342,847	₩ 371,301	₩ 359,937	₩ 358,497
Acquisition cost
Disclosure of investment property [Line Items]
Net carrying value	417,692		404,741
Accumulated depreciation
Disclosure of investment property [Line Items]
Net carrying value	₩ (36,515)		₩ (33,440)

Investment properties_Reconcili

Investment properties_Reconciliation of investment properties (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Reconciliation of changes in investment property [Abstract]
Beginning balance	₩ 371,301,000,000		₩ 358,497,000,000
Changes in investment property [Abstract]
Acquisition	7,311,000,000		1,221,000,000
Disposal	(1,738,000,000)		(225,000,000)
Depreciation	(2,010,000,000)		(1,991,000,000)
Transfer	6,333,000,000		(2,708,000,000)
Classified to assets held for sale	0		(534,000,000)
Foreign currencies translation adjustments	(79,000,000)		(120,000,000)
Others	59,000,000		5,797,000,000
Ending balance	₩ 381,177,000,000	$ 342,847	₩ 359,937,000,000

Investment properties_Rental fe

Investment properties_Rental fee earned from investment properties (Details) - KRW (₩) ₩ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Rental income from investment property net of direct operating expense [Abstract]
Rental fee earned from investment properties	₩ 2,396	₩ 2,411

Premises and equipment_Details

Premises and equipment_Details of premises and equipment (Details) $ in Thousands	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)	Jun. 30, 2017KRW (₩)	Dec. 31, 2016KRW (₩)
Disclosure of property plant and equipment [Line Items]
Net carrying value	₩ 2,450,754,000,000	$ 2,204,312	₩ 2,477,545,000,000	₩ 2,459,176,000,000	₩ 2,458,025,000,000
Acquisition cost
Disclosure of property plant and equipment [Line Items]
Net carrying value	3,896,977,000,000		3,873,512,000,000
Accumulated depreciation
Disclosure of property plant and equipment [Line Items]
Net carrying value	(1,446,223,000,000)		(1,395,967,000,000)
Land
Disclosure of property plant and equipment [Line Items]
Net carrying value	1,482,169,000,000		1,487,278,000,000	1,488,266,000,000	1,488,745,000,000
Land | Acquisition cost
Disclosure of property plant and equipment [Line Items]
Net carrying value	1,482,169,000,000		1,487,278,000,000
Building
Disclosure of property plant and equipment [Line Items]
Net carrying value	665,815,000,000		680,846,000,000	681,692,000,000	691,699,000,000
Building | Acquisition cost
Disclosure of property plant and equipment [Line Items]
Net carrying value	863,503,000,000		867,804,000,000
Building | Accumulated depreciation
Disclosure of property plant and equipment [Line Items]
Net carrying value	(197,688,000,000)		(186,958,000,000)
Properties for business use
Disclosure of property plant and equipment [Line Items]
Net carrying value	236,261,000,000		180,072,000,000	188,225,000,000	189,902,000,000
Properties for business use | Acquisition cost
Disclosure of property plant and equipment [Line Items]
Net carrying value	1,105,029,000,000		1,024,186,000,000
Properties for business use | Accumulated depreciation
Disclosure of property plant and equipment [Line Items]
Net carrying value	(868,768,000,000)		(844,114,000,000)
Structures in leased office
Disclosure of property plant and equipment [Line Items]
Net carrying value	62,085,000,000		64,787,000,000	63,113,000,000	68,958,000,000
Structures in leased office | Acquisition cost
Disclosure of property plant and equipment [Line Items]
Net carrying value	441,835,000,000		429,665,000,000
Structures in leased office | Accumulated depreciation
Disclosure of property plant and equipment [Line Items]
Net carrying value	(379,750,000,000)		(364,878,000,000)
Construction in progress
Disclosure of property plant and equipment [Line Items]
Net carrying value	4,421,000,000		64,559,000,000	37,877,000,000	18,717,000,000
Construction in progress | Acquisition cost
Disclosure of property plant and equipment [Line Items]
Net carrying value	4,421,000,000		64,559,000,000
Construction in progress | Accumulated depreciation
Disclosure of property plant and equipment [Line Items]
Net carrying value	0		0
Structures
Disclosure of property plant and equipment [Line Items]
Net carrying value	3,000,000		3,000,000	₩ 3,000,000	₩ 4,000,000
Structures | Acquisition cost
Disclosure of property plant and equipment [Line Items]
Net carrying value	20,000,000		20,000,000
Structures | Accumulated depreciation
Disclosure of property plant and equipment [Line Items]
Net carrying value	₩ (17,000,000)		₩ (17,000,000)

Premises and equipment_Reconcil

Premises and equipment_Reconciliation of premises and equipment (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Reconciliation of changes in property plant and equipment [Abstract]
Beginning balance	₩ 2,477,545,000,000		₩ 2,458,025,000,000
Changes in property plant and equipment [Abstract]
Acquisition	42,694,000,000		68,628,000,000
Disposal	(161,000,000)		(1,469,000,000)
Depreciation	(66,800,000,000)		(69,346,000,000)
Classified to assets held for sale	(6,050,000,000)		(2,184,000,000)
Transfer	(6,333,000,000)		2,708,000,000
Foreign currencies translation adjustment	584,000,000		(2,754,000,000)
Acquisition through business combination	1,630,000,000		0
Others	7,645,000,000		5,568,000,000
Ending balance	2,450,754,000,000	$ 2,204,312	2,459,176,000,000
Land
Reconciliation of changes in property plant and equipment [Abstract]
Beginning balance	1,487,278,000,000		1,488,745,000,000
Changes in property plant and equipment [Abstract]
Acquisition	463,000,000		0
Disposal	0		(606,000,000)
Depreciation	0		0
Classified to assets held for sale	(3,573,000,000)		(1,743,000,000)
Transfer	(1,910,000,000)		2,466,000,000
Foreign currencies translation adjustment	(89,000,000)		(596,000,000)
Acquisition through business combination	0		0
Others	0		0
Ending balance	1,482,169,000,000		1,488,266,000,000
Building
Reconciliation of changes in property plant and equipment [Abstract]
Beginning balance	680,846,000,000		691,699,000,000
Changes in property plant and equipment [Abstract]
Acquisition	4,326,000,000		3,831,000,000
Disposal	0		(205,000,000)
Depreciation	(12,960,000,000)		(13,029,000,000)
Classified to assets held for sale	(2,477,000,000)		(441,000,000)
Transfer	(4,423,000,000)		403,000,000
Foreign currencies translation adjustment	(121,000,000)		(560,000,000)
Acquisition through business combination	0		0
Others	624,000,000		(6,000,000)
Ending balance	665,815,000,000		681,692,000,000
Properties for business use
Reconciliation of changes in property plant and equipment [Abstract]
Beginning balance	180,072,000,000		189,902,000,000
Changes in property plant and equipment [Abstract]
Acquisition	27,635,000,000		31,624,000,000
Disposal	(72,000,000)		(235,000,000)
Depreciation	(36,144,000,000)		(38,063,000,000)
Classified to assets held for sale	0		0
Transfer	63,433,000,000		5,485,000,000
Foreign currencies translation adjustment	352,000,000		(676,000,000)
Acquisition through business combination	969,000,000		0
Others	16,000,000		188,000,000
Ending balance	236,261,000,000		188,225,000,000
Structures in leased office
Reconciliation of changes in property plant and equipment [Abstract]
Beginning balance	64,787,000,000		68,958,000,000
Changes in property plant and equipment [Abstract]
Acquisition	6,928,000,000		8,120,000,000
Disposal	(89,000,000)		(423,000,000)
Depreciation	(17,696,000,000)		(18,253,000,000)
Classified to assets held for sale	0		0
Transfer	0		0
Foreign currencies translation adjustment	489,000,000		(675,000,000)
Acquisition through business combination	661,000,000		0
Others	7,005,000,000		5,386,000,000
Ending balance	62,085,000,000		63,113,000,000
Construction in progress
Reconciliation of changes in property plant and equipment [Abstract]
Beginning balance	64,559,000,000		18,717,000,000
Changes in property plant and equipment [Abstract]
Acquisition	3,342,000,000		25,053,000,000
Disposal	0		0
Depreciation	0		0
Classified to assets held for sale	0		0
Transfer	(63,433,000,000)		(5,646,000,000)
Foreign currencies translation adjustment	(47,000,000)		(247,000,000)
Acquisition through business combination	0		0
Others	0		0
Ending balance	4,421,000,000		37,877,000,000
Structures
Reconciliation of changes in property plant and equipment [Abstract]
Beginning balance	3,000,000		4,000,000
Changes in property plant and equipment [Abstract]
Acquisition	0		0
Disposal	0		0
Depreciation	0		(1,000,000)
Classified to assets held for sale	0		0
Transfer	0		0
Foreign currencies translation adjustment	0		0
Acquisition through business combination	0		0
Others	0		0
Ending balance	₩ 3,000,000		₩ 3,000,000

Intangible assets_Details of in

Intangible assets_Details of intangible assets (Details) $ in Thousands	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)	Jun. 30, 2017KRW (₩)	Dec. 31, 2016KRW (₩)
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	₩ 653,514,000,000	$ 587,798	₩ 518,599,000,000	₩ 506,882,000,000	₩ 483,739,000,000
Acquisition cost
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	1,579,965,000,000		1,387,971,000,000
Accumulated amortization
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	(921,486,000,000)		(862,583,000,000)
Accumulated impairment losses
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	(4,965,000,000)		(6,789,000,000)
Goodwill
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	154,644,000,000		108,707,000,000	117,429,000,000	124,803,000,000
Goodwill | Acquisition cost
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	154,644,000,000		108,707,000,000
Goodwill | Accumulated amortization
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	0		0
Goodwill | Accumulated impairment losses
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	0		0
Software
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	37,683,000,000		40,672,000,000	45,566,000,000	35,477,000,000
Software | Acquisition cost
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	208,383,000,000		203,418,000,000
Software | Accumulated amortization
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	(170,700,000,000)		(162,746,000,000)
Software | Accumulated impairment losses
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	0		0
Industrial property rights
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	569,000,000		539,000,000	311,000,000	313,000,000
Industrial property rights | Acquisition cost
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	1,180,000,000		1,063,000,000
Industrial property rights | Accumulated amortization
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	(611,000,000)		(524,000,000)
Industrial property rights | Accumulated impairment losses
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	0		0
Development costs
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	264,182,000,000		77,241,000,000	71,755,000,000	70,697,000,000
Development costs | Acquisition cost
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	463,361,000,000		260,087,000,000
Development costs | Accumulated amortization
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	(199,179,000,000)		(182,846,000,000)
Development costs | Accumulated impairment losses
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	0		0
Others
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	166,199,000,000		117,546,000,000	136,863,000,000	164,364,000,000
Others | Acquisition cost
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	717,332,000,000		634,150,000,000
Others | Accumulated amortization
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	(550,996,000,000)		(516,467,000,000)
Others | Accumulated impairment losses
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	(137,000,000)		(137,000,000)
Membership deposit
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	21,259,000,000		20,685,000,000	19,485,000,000	20,086,000,000
Membership deposit | Acquisition cost
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	26,087,000,000		27,337,000,000
Membership deposit | Accumulated amortization
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	0		0
Membership deposit | Accumulated impairment losses
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	(4,828,000,000)		(6,652,000,000)
Construction in progress
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	8,978,000,000		153,209,000,000	₩ 115,473,000,000	₩ 67,999,000,000
Construction in progress | Acquisition cost
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	8,978,000,000		153,209,000,000
Construction in progress | Accumulated amortization
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	0		0
Construction in progress | Accumulated impairment losses
Disclosure of reconciliation of changes in intangible assets and goodwill [Line Items]
Net carrying value	₩ 0		₩ 0

Intangible Assets_Reconciliatio

Intangible Assets_Reconciliation of intangible assets (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Reconciliation of changes in intangible assets and goodwill [Abstract]
Beginning balance	₩ 518,599,000,000			₩ 483,739,000,000
Changes in intangible assets and goodwill [Abstract]
Acquisition	148,129,000,000			89,679,000,000
Disposal	(2,107,000,000)			(866,000,000)
Amortization	(58,076,000,000)			(50,024,000,000)
Impairment losses	0			(128,000,000)
Reversal of impairment loss	339,000,000			0
Transfer	0			0
Acquisition through business combination	48,169,000,000			0
Foreign currencies translation adjustment	(1,131,000,000)			(9,064,000,000)
Others	(408,000,000)			(6,454,000,000)
Ending balance	653,514,000,000		$ 587,798	506,882,000,000
Amortisation of other intangible assets included in other operating expenses	25,179,000,000	[1]		24,443,000,000	[2]
Goodwill
Reconciliation of changes in intangible assets and goodwill [Abstract]
Beginning balance	108,707,000,000			124,803,000,000
Changes in intangible assets and goodwill [Abstract]
Acquisition	0			105,000,000
Disposal	0			0
Amortization	0			0
Impairment losses	0			0
Reversal of impairment loss	0			0
Transfer	0			0
Acquisition through business combination	47,406,000,000			0
Foreign currencies translation adjustment	(1,469,000,000)			(7,479,000,000)
Others	0			0
Ending balance	154,644,000,000			117,429,000,000
Software
Reconciliation of changes in intangible assets and goodwill [Abstract]
Beginning balance	40,672,000,000			35,477,000,000
Changes in intangible assets and goodwill [Abstract]
Acquisition	3,737,000,000			10,152,000,000
Disposal	0			0
Amortization	(7,510,000,000)			(8,064,000,000)
Impairment losses	0			0
Reversal of impairment loss	0			0
Transfer	0			8,091,000,000
Acquisition through business combination	763,000,000			0
Foreign currencies translation adjustment	21,000,000			(68,000,000)
Others	0			(22,000,000)
Ending balance	37,683,000,000			45,566,000,000
Industrial property rights
Reconciliation of changes in intangible assets and goodwill [Abstract]
Beginning balance	539,000,000			313,000,000
Changes in intangible assets and goodwill [Abstract]
Acquisition	117,000,000			54,000,000
Disposal	0			0
Amortization	(87,000,000)			(56,000,000)
Impairment losses	0			0
Reversal of impairment loss	0			0
Transfer	0			0
Acquisition through business combination	0			0
Foreign currencies translation adjustment	0			0
Others	0			0
Ending balance	569,000,000			311,000,000
Development costs
Reconciliation of changes in intangible assets and goodwill [Abstract]
Beginning balance	77,241,000,000			70,697,000,000
Changes in intangible assets and goodwill [Abstract]
Acquisition	21,455,000,000			12,628,000,000
Disposal	0			0
Amortization	(16,317,000,000)			(11,515,000,000)
Impairment losses	0			0
Reversal of impairment loss	0			0
Transfer	181,803,000,000			0
Acquisition through business combination	0			0
Foreign currencies translation adjustment	0			0
Others	0			(55,000,000)
Ending balance	264,182,000,000			71,755,000,000
Others
Reconciliation of changes in intangible assets and goodwill [Abstract]
Beginning balance	117,546,000,000			164,364,000,000
Changes in intangible assets and goodwill [Abstract]
Acquisition	36,191,000,000			10,276,000,000
Disposal	0			0
Amortization	(34,162,000,000)	[1]		(30,389,000,000)	[2]
Impairment losses	0			0
Reversal of impairment loss	0			0
Transfer	46,746,000,000			36,000,000
Acquisition through business combination	0			0
Foreign currencies translation adjustment	243,000,000			(1,053,000,000)
Others	(365,000,000)			(6,371,000,000)
Ending balance	166,199,000,000			136,863,000,000
Amortisation of other intangible assets included in other operating expenses	25,179,000,000	[1]		24,443,000,000	[2]
Membership deposit
Reconciliation of changes in intangible assets and goodwill [Abstract]
Beginning balance	20,685,000,000			20,086,000,000
Changes in intangible assets and goodwill [Abstract]
Acquisition	2,311,000,000			480,000,000
Disposal	(2,107,000,000)			(866,000,000)
Amortization	0			0
Impairment losses	0			(128,000,000)
Reversal of impairment loss	339,000,000			0
Transfer	0			0
Acquisition through business combination	0			0
Foreign currencies translation adjustment	74,000,000			(81,000,000)
Others	(43,000,000)			(6,000,000)
Ending balance	21,259,000,000			19,485,000,000
Construction in progress
Reconciliation of changes in intangible assets and goodwill [Abstract]
Beginning balance	153,209,000,000			67,999,000,000
Changes in intangible assets and goodwill [Abstract]
Acquisition	84,318,000,000			55,984,000,000
Disposal	0			0
Amortization	0			0
Impairment losses	0			0
Reversal of impairment loss	0			0
Transfer	(228,549,000,000)			(8,127,000,000)
Acquisition through business combination	0			0
Foreign currencies translation adjustment	0			(383,000,000)
Others	0			0
Ending balance	₩ 8,978,000,000			₩ 115,473,000,000
[1]	Amortization of other intangible assets amounting to 25,179 million Won is included in other operating expenses.
[2]	Amortization of other intangible assets amounting to 24,443 million Won is included in other operating expenses.

Assets held for sale_Details of

Assets held for sale_Details of assets held for sale (Details) $ in Thousands, ₩ in Millions		Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Noncurrent assets or disposal groups classified as held for sale [Line Items]
Total		₩ 18,705	$ 16,824	₩ 48,624
Investments in joint ventures and associates
Noncurrent assets or disposal groups classified as held for sale [Line Items]
Total		5,865		46,217
Premises and equipment
Noncurrent assets or disposal groups classified as held for sale [Line Items]
Total	[1]	12,840		2,407
Non-current assets classified as held for sale out of assets of consolidated subsidiaries	[1]	₩ 5,223		₩ 840
[1]	As of June 30, 2018 and December 31, 2017, non-operating assets of the subsidiaries include land and buildings classified as assets held for sale amounting to 5,223 million Won and 840 million Won, respectively.

Assets subject to lien and a179

Assets subject to lien and assets acquired through foreclosures_Assets subjected to lien (Details) - KRW (₩) ₩ in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2018	Dec. 31, 2017
Financial instruments owned and pledged as collateral [Line Items]
Amount		₩ 6,780,509	₩ 9,725,617
Due from banks on time in local currency
Financial instruments owned and pledged as collateral [Line Items]
Amount		₩ 1,500
Collateral given to		DaishinAMC and others
Reason for collateral		Right of pledge
Due from banks in local currency
Financial instruments owned and pledged as collateral [Line Items]
Amount		₩ 19,698
Collateral given to		Samsung Securities Co., Ltd. and others
Reason for collateral		Margin deposit for futures or option
Due from banks in foreign currencies
Financial instruments owned and pledged as collateral [Line Items]
Amount		₩ 135,515
Collateral given to		Korea Investment & Securities Co., Ltd. and others
Reason for collateral		Foreign margin deposit for future or option and others
Korean financial institutions debt securities and others
Financial instruments owned and pledged as collateral [Line Items]
Amount		₩ 72,915
Collateral given to		Kyobo Life Insurance,.ltd and others
Reason for collateral		CSA collateral and others
Korean treasury and corporate bonds
Financial instruments owned and pledged as collateral [Line Items]
Amount		₩ 10,002
Collateral given to		Korea Securities Depository
Reason for collateral	[1]	Related to bonds sold under repurchase agreements
Korean treasury and government agencies bonds and others
Financial instruments owned and pledged as collateral [Line Items]
Amount		₩ 1,621,221
Collateral given to		The BOK and others
Reason for collateral		Settlement risk and others
Korean treasury and government agencies bonds
Financial instruments owned and pledged as collateral [Line Items]
Amount		₩ 5,444
Collateral given to		Korea Securities Depository The BOK and others
Reason for collateral	[1]	Related to bonds sold under repurchase agreements
Korean financial institutions debt securities and others
Financial instruments owned and pledged as collateral [Line Items]
Amount		₩ 4,908,149
Collateral given to		The BOK and others
Reason for collateral		Settlement risk and others
Due from banks on time in local currency
Financial instruments owned and pledged as collateral [Line Items]
Amount			₩ 6,629
Collateral given to			Bank of China and others
Reason for collateral			Collaterals for issuing letter of guarantee and others
Due from banks in local currency
Financial instruments owned and pledged as collateral [Line Items]
Amount			₩ 10,809
Collateral given to			Samsung Securities Co., Ltd. and others
Reason for collateral			Margin deposit for futures or option
Due from banks in foreign currencies
Financial instruments owned and pledged as collateral [Line Items]
Amount			₩ 9,136
Collateral given to			Korea Investment & Securities Co., Ltd. and others
Reason for collateral			Foreign margin deposit for future or option and others
Korean financial institutions debt securities and others
Financial instruments owned and pledged as collateral [Line Items]
Amount			₩ 501,523
Collateral given to			Yuanta Securities Co., Ltd. and others
Reason for collateral			Substitute securities and others
Korean treasury and corporate bonds
Financial instruments owned and pledged as collateral [Line Items]
Amount			₩ 9,998
Collateral given to			Korea Securities Depository and others
Reason for collateral	[1]		Related to bonds sold under repurchase agreements
Korean treasury and government agencies bonds and others
Financial instruments owned and pledged as collateral [Line Items]
Amount			₩ 1,570,608
Collateral given to			The BOK and others
Reason for collateral			Settlement risk and others
Korean treasury and government agencies bonds
Financial instruments owned and pledged as collateral [Line Items]
Amount			₩ 5,436
Collateral given to			Korea Securities Depository
Reason for collateral	[1]		Related to bonds sold under repurchase agreements
Korean financial institutions debt securities and others
Financial instruments owned and pledged as collateral [Line Items]
Amount			₩ 7,605,292
Collateral given to			The BOK and others
Reason for collateral			Settlement risk and others
Land and building
Financial instruments owned and pledged as collateral [Line Items]
Amount		₩ 6,065	₩ 6,186
Collateral given to		Credit Counselling & Recovery Service and others	Credit Counselling & Recovery Service and others
Reason for collateral		Right to collateral and others	Leasehold rights and others
[1]	The Group has the agreements to repurchase the sold assets at the predetermined price or the price that includes the rate of return and to provide the guarantee on the assets. The transferee has the right to sell or to provide as guarantee. Therefore, the Group does not derecognize the assets, but recognizes the relevant amounts as liability (bonds sold under repurchase agreements).

Assets subject to lien and a180

Assets subject to lien and assets acquired through foreclosures_Carrying amounts of buildings acquired through foreclosure (Details) - KRW (₩)	Jun. 30, 2018	Dec. 31, 2017
Disclsoure of carrying amounts o assets acquired through foreclosure [Abstract]
Land	₩ 327,000,000	₩ 332,000,000
Buildings	0	44,000,000
Total	₩ 327,000,000	₩ 376,000,000

Assets subject to lien and a181

Assets subject to lien and assets acquired through foreclosures_Details of securities lent (Details) - KRW (₩)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Nature of financial assets transferred during period which do not qualify for derecognition
Loaned securities
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Assets that entity continues to recognise	₩ 50,139,000,000	₩ 170,256,000,000
Nature of financial assets transferred during period which do not qualify for derecognition	Securities loaned are lending of specific securities to borrowers who agree to return the same quantity of the same security at the end of lending period. As the Group does not derecognize these securities, there are no liabilities recognized through such transactions relates to securities loaned.	Securities loaned are lending of specific securities to borrowers who agree to return the same quantity of the same security at the end of lending period. As the Group does not derecognize these securities, there are no liabilities recognized through such transactions relates to securities loaned.
Korean treasury, corporate bonds and others
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Assets that entity continues to recognise	₩ 50,139,000,000	₩ 0
Loaned to	Korea Securities Finance Corporation
Korean treasury and government bonds and others
Disclosure of financial assets transferred during period which do not qualify for derecognition [Line Items]
Assets that entity continues to recognise	₩ 0	₩ 170,256,000,000
Loaned to		Korea Securities Finance Corporation and others

Assets subject to lien and a182

Assets subject to lien and assets acquired through foreclosures_Collaterals held that can be disposed and recollateralized regardless of defaults of counterparties (Details) - KRW (₩)	Jun. 30, 2018	Dec. 31, 2017
Fair value of collateral available to sell or repledge and collateral sold or repledged [Line Items]
Fair values of collaterals	₩ 7,303,137,000,000	₩ 17,671,490,000,000
Fair values of collaterals were disposed or re-subjected to lien	₩ 0	₩ 0

Other assets_Details of other a

Other assets_Details of other assets (Details) $ in Thousands, ₩ in Millions	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Other assests [Line Items]
Total	₩ 202,800	$ 182,406	₩ 158,404
Prepaid expenses
Other assests [Line Items]
Total	165,150		130,245
Advance payments
Other assests [Line Items]
Total	24,879		18,363
Non-operative assets
Other assests [Line Items]
Total	327		376
Others
Other assests [Line Items]
Total	₩ 12,444		₩ 9,420

Financial liabilities at FVTPL_

Financial liabilities at FVTPL_Details of financial liabilities at FVTPL (Details)	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)		Dec. 31, 2017KRW (₩)	Jun. 30, 2017KRW (₩)
Disclosure of financial liabilities at fair value through profit or loss [Line Items]
Financial liabilities at FVTPL	₩ 2,402,235,000,000				₩ 0
Financial liabilities held for trading	0				3,176,113,000,000
Financial liabilities at fair value through profit or loss designated as upon initial recognition	176,097,000,000				0	₩ 0
Financial liabilities designated at FVTPL (IAS 39)	0				251,796,000,000	₩ 616,177,000,000
Financial liabilities at FVTPL	2,578,332,000,000	[1]	$ 2,319,061,000	[1]	0
Financial liabilities at fair value through profit or loss in accordance with IAS 39	0		$ 0		3,427,909,000,000
Gold banking liabilities
Disclosure of financial liabilities at fair value through profit or loss [Line Items]
Financial liabilities at FVTPL	24,485,000,000
Financial liabilities held for trading					25,964,000,000
Derivative liabilities
Disclosure of financial liabilities at fair value through profit or loss [Line Items]
Financial liabilities at FVTPL	2,377,750,000,000
Financial liabilities held for trading					3,150,149,000,000
Equity linked securities index in short position
Disclosure of financial liabilities at fair value through profit or loss [Line Items]
Financial liabilities at fair value through profit or loss designated as upon initial recognition	176,097,000,000
Financial liabilities designated at FVTPL (IAS 39)					160,057,000,000
Debentures in local currency
Disclosure of financial liabilities at fair value through profit or loss [Line Items]
Financial liabilities designated at FVTPL (IAS 39)	₩ 0				₩ 91,739,000,000
[1]	The consolidated interim statements of financial position as of June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated statements of financial position as of December 31, 2017 were not retrospectively restated accordance with IFRS 9.

Financial liabilities at FVT185

Financial liabilities at FVTPL_Credit risk adjustments to financial liabilities at FVTPL (Details) - KRW (₩)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Designated financial liabilities at fair value through profit or loss [Abstract]
Financial liabilities at fair value through profit or loss designated as upon initial recognition	₩ 176,097,000,000	₩ 0	₩ 0
Financial liabilities designated at FVTPL (IAS 39)	0	616,177,000,000	₩ 251,796,000,000
Credit risk adjustments	(179,000,000)	(261,000,000)
Accumulated changes in credit risk adjustments	₩ (39,000,000)	₩ 89,000,000
Additional information about credit risk adjustments	The adjustment to reflect Group’s credit risk is considered in measuring the fair value of derivatives. The Group’s credit risk is determined by adjusting credit spread observed in credit rating of bank.	The adjustment to reflect Group’s credit risk is considered in measuring the fair value of derivatives. The Group’s credit risk is determined by adjusting credit spread observed in credit rating of bank.

Financial liabilities at FVT186

Financial liabilities at FVTPL_Difference between carrying amount and nominal amount at maturity of financial liabilities at fair value through profit or loss designated as upon initial recognition (Details) - KRW (₩)	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Disclosure of difference between carrying amount and nominal amountat maturityof financial liabilities at fair value through profit or loss designated as upon initial recognition [Abstract]
Carrying amount	₩ 176,097,000,000	₩ 0	₩ 0
Carrying amount Financial liabilities designated as at FVTPL (IAS39)	0	251,796,000,000	₩ 616,177,000,000
Nominal amount at maturity	212,259,000,000	255,408,000,000
Difference	₩ (36,162,000,000)	₩ (3,612,000,000)

Financial liabilities at FVT187

Financial liabilities at FVTPL_Capital fluctuation in financial liabilities at fair value through profit or loss designated as upon initial recognition (Details) ₩ in Millions	6 Months Ended
	Jun. 30, 2018KRW (₩)
Disclosure of changes in equity in relation to financial liabilities at fair value through profit or loss designated as upon initial recognition [Abstract]
Equity-linked securities index	₩ (8)

Deposits due to customers_Detai

Deposits due to customers_Details of deposits due to customers by type (Details) $ in Thousands, ₩ in Millions	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Disclosure of deposits from customers [Line Items]
Total	₩ 237,900,166	$ 213,977,483	₩ 234,695,084
Present value discount
Disclosure of deposits from customers [Line Items]
Total	(43,167)		(40,010)
Deposits in local currency
Disclosure of deposits from customers [Line Items]
Total	215,993,292		211,052,198
Deposits in local currency | Deposits on demand | Gross carrying amount [Member]
Disclosure of deposits from customers [Line Items]
Total	9,337,563		9,349,070
Deposits in local currency | Deposits at termination | Gross carrying amount [Member]
Disclosure of deposits from customers [Line Items]
Total	198,768,356		194,292,679
Deposits in local currency | Mutual funds | Gross carrying amount [Member]
Disclosure of deposits from customers [Line Items]
Total	32,292		34,055
Deposits in local currency | Deposits on notes payables | Gross carrying amount [Member]
Disclosure of deposits from customers [Line Items]
Total	1,705,871		1,323,679
Deposits in local currency | Deposits on CMA | Gross carrying amount [Member]
Disclosure of deposits from customers [Line Items]
Total	154,782		164,431
Deposits in local currency | Certificate of deposits | Gross carrying amount [Member]
Disclosure of deposits from customers [Line Items]
Total	4,592,575		4,436,443
Deposits in local currency | Other deposits | Gross carrying amount [Member]
Disclosure of deposits from customers [Line Items]
Total	1,401,853		1,451,841
Due from banks in foreign currencies | Deposits in foreign currencies | Gross carrying amount [Member]
Disclosure of deposits from customers [Line Items]
Total	₩ 21,950,041		₩ 23,682,896

Borrowings and debentures_Detai

Borrowings and debentures_Details of borrowings (Details) $ in Thousands, ₩ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018KRW (₩)	Dec. 31, 2017KRW (₩)	Jun. 30, 2018USD ($)
Disclosure of detailed information about borrowings [Line Items]
Total	₩ 15,899,599	₩ 14,784,706	$ 14,300,773
Present value discount
Disclosure of detailed information about borrowings [Line Items]
Total	(27)	(165)
Borrowings in local currency
Disclosure of detailed information about borrowings [Line Items]
Total		7,084,848
Borrowings in local currency | Gross carrying amount [Member]
Disclosure of detailed information about borrowings [Line Items]
Total	7,869,438
Borrowings from The BOK | Gross carrying amount [Member]
Disclosure of detailed information about borrowings [Line Items]
Total	₩ 1,420,990	₩ 1,404,087
Lenders	The BOK	The BOK
Borrowings from The BOK | Gross carrying amount [Member] | Bottom of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	0.50%	0.50%	0.50%
Borrowings from The BOK | Gross carrying amount [Member] | Top of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	0.80%	0.80%	0.80%
Small Enterprise And Market Service and others | Gross carrying amount [Member]
Disclosure of detailed information about borrowings [Line Items]
Total	₩ 1,782,603	₩ 1,723,340
Lenders	Small Enterprise And Market Service and others	Small Enterprise And Market Service and others
Small Enterprise And Market Service and others | Gross carrying amount [Member] | Bottom of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	0.00%	0.00%	0.00%
Small Enterprise And Market Service and others | Gross carrying amount [Member] | Top of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	2.50%	2.90%	2.50%
The Korea Development Bank and others | Gross carrying amount [Member]
Disclosure of detailed information about borrowings [Line Items]
Total	₩ 4,665,845	₩ 3,957,421
Lenders	The Korea Development Bank and others	The Korea Development Bank and others
The Korea Development Bank and others | Gross carrying amount [Member] | Bottom of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	0.00%	0.00%	0.00%
The Korea Development Bank and others | Gross carrying amount [Member] | Top of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	4.00%	3.20%	4.00%
Borrowings in foreign currency
Disclosure of detailed information about borrowings [Line Items]
Total		₩ 7,024,836
Borrowings in foreign currency | Gross carrying amount [Member]
Disclosure of detailed information about borrowings [Line Items]
Total	₩ 7,182,053
The Export-Import BOK and others | Gross carrying amount [Member]
Disclosure of detailed information about borrowings [Line Items]
Total	₩ 7,148,402	₩ 6,996,551
Lenders	The Export-Import BOK and others	The Export-Import BOK and others
The Export-Import BOK and others | Gross carrying amount [Member] | Bottom of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	0.00%	0.00%	0.00%
The Export-Import BOK and others | Gross carrying amount [Member] | Top of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	6.50%	6.80%	6.50%
JP Morgan | Gross carrying amount [Member]
Disclosure of detailed information about borrowings [Line Items]
Total	₩ 33,651
Lenders	JPMORGAN CHASE BANK
JP Morgan | Gross carrying amount [Member] | Top of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	2.80%		2.80%
Commonwealth Bank | Gross carrying amount [Member]
Disclosure of detailed information about borrowings [Line Items]
Total		₩ 28,285
Lenders		Commonwealth Bank
Commonwealth Bank | Gross carrying amount [Member] | Top of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate		1.80%
Bills sold | Gross carrying amount [Member]
Disclosure of detailed information about borrowings [Line Items]
Total	₩ 23,874	₩ 36,953
Lenders	Others	Others
Bills sold | Gross carrying amount [Member] | Bottom of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	0.00%	0.00%	0.00%
Bills sold | Gross carrying amount [Member] | Top of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	1.20%	1.20%	1.20%
Call money | Gross carrying amount [Member]
Disclosure of detailed information about borrowings [Line Items]
Total	₩ 818,889	₩ 635,061
Lenders	Bank and others	Bank and others
Call money | Gross carrying amount [Member] | Bottom of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	0.00%	1.50%	0.00%
Call money | Gross carrying amount [Member] | Top of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	6.30%	2.70%	6.30%
Bonds sold under repurchase agreements | Gross carrying amount [Member]
Disclosure of detailed information about borrowings [Line Items]
Total	₩ 5,372	₩ 3,173
Lenders	Other financial institutions	Other financial institutions
Bonds sold under repurchase agreements | Gross carrying amount [Member] | Bottom of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	0.70%	0.60%	0.70%
Bonds sold under repurchase agreements | Gross carrying amount [Member] | Top of range [Member]
Disclosure of detailed information about borrowings [Line Items]
Interest rate	12.70%	12.70%	12.70%

Borrowings and debentures_De190

Borrowings and debentures_Details of debentures (Details) $ in Thousands, ₩ in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2018KRW (₩)	Dec. 31, 2017KRW (₩)	Jun. 30, 2018USD ($)
Disclosure of detailed information about debentures [Line Items]
Total		₩ 26,752,725	₩ 27,869,651	$ 24,062,534
Fair value hedged amount of debentures	[1]	3,150,145	3,089,751
Cash flow hedged amount of debentures	[1]	724,487	694,548
Discounts on bond
Disclosure of detailed information about debentures [Line Items]
Total		(35,616)	(30,173)
Face value of bond | Gross carrying amount [Member]
Disclosure of detailed information about debentures [Line Items]
Total		26,788,341	27,899,824
Ordinary bonds | Gross carrying amount [Member]
Disclosure of detailed information about debentures [Line Items]
Total		₩ 21,105,565	₩ 22,468,908
Ordinary bonds | Gross carrying amount [Member] | Bottom of range [Member]
Disclosure of detailed information about debentures [Line Items]
Interest rate		1.50%	1.50%
Ordinary bonds | Gross carrying amount [Member] | Top of range [Member]
Disclosure of detailed information about debentures [Line Items]
Interest rate		4.50%	5.80%
Subordinated bonds | Gross carrying amount [Member]
Disclosure of detailed information about debentures [Line Items]
Total		₩ 5,006,632	₩ 4,781,301
Subordinated bonds | Gross carrying amount [Member] | Bottom of range [Member]
Disclosure of detailed information about debentures [Line Items]
Interest rate		3.00%	3.40%
Subordinated bonds | Gross carrying amount [Member] | Top of range [Member]
Disclosure of detailed information about debentures [Line Items]
Interest rate		12.60%	12.60%
Other bonds | Gross carrying amount [Member]
Disclosure of detailed information about debentures [Line Items]
Total		₩ 676,144	₩ 649,615
Other bonds | Gross carrying amount [Member] | Bottom of range [Member]
Disclosure of detailed information about debentures [Line Items]
Interest rate		1.90%	1.60%
Other bonds | Gross carrying amount [Member] | Top of range [Member]
Disclosure of detailed information about debentures [Line Items]
Interest rate		17.00%	17.00%
[1]	Included debentures under fair value hedge relationships are 3,150,145 million Won and 3,089,751 million Won as of June 30, 2018 and December 31, 2017, respectively. Also, debentures under cash flow hedge amounting to 724,487 million Won and 694,548 million Won are included as of June 30, 2018 and December 31, 2017.

Provisions_Details of provision

Provisions_Details of provisions (Details) $ in Thousands, ₩ in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2018KRW (₩)	Dec. 31, 2017KRW (₩)	Jun. 30, 2018USD ($)
Disclosure of other provisions [Line Items]
Provisions		₩ 386,374	₩ 410,470	$ 347,521
Asset retirement obligation
Disclosure of other provisions [Line Items]
Provisions		67,458	61,872
Provision for guarantee
Disclosure of other provisions [Line Items]
Provisions	[1]	₩ 106,827	₩ 183,247
Description of nature of provisions for guarantee	[1]	Provision for guarantee includes provision for financial guarantee of 54,896 million Won and 71,697 million Won as of June 30, 2018 and December 31, 2017, respectively.	Provision for guarantee includes provision for financial guarantee of 66,953 million Won and 71,697 million Won as of March 31, 2018 and December 31, 2017, respectively.
Provision for financial guarantee contract	[1]	₩ 54,896	₩ 71,697
Provision for unused commitments
Disclosure of other provisions [Line Items]
Provisions		101,874	66,115
Provisions for customer reward credits
Disclosure of other provisions [Line Items]
Provisions		46,735	40,445
Other provisions
Disclosure of other provisions [Line Items]
Provisions	[2]	₩ 63,480	₩ 58,791
Description of nature of miscellaneous other provisions	[2]	Other provisions consist of provision for litigation and others.	Other provisions consist of provision for litigation and others.
[1]	Provisions for guarantees includes provision for financial guarantee of 54,896 million Won and 71,697 million Won as of June 30, 2018 and December 31, 2017, respectively.
[2]	Other provisions consist of provision for litigation and others.

Provisions_Details of provis192

Provisions_Details of provisions for guarantee (Details) - KRW (₩)		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
Reconciliation of changes in provisions for payment guarantee [Abstract]
Beginning balance	[1]	₩ 192,924,000,000
Beginning balance		183,247,000,000	₩ 238,117,000,000
Changes in provisions for payment guarantee [Abstract]
Replaced by 12-month expected credit loss		0
Replaced with expected credit loss for the entire period		0
Replaced with credit-impaired financial assets		0
Provisions provided			1,003,000,000
Provisions used		(8,506,000,000)	(12,335,000,000)
Unused provision reversed provisions for payment guarantee		(86,990,000,000)	(45,971,000,000)
Foreign currencies translation adjustments			20,000,000
Others		9,399,000,000	7,920,000,000
Ending balance		106,827,000,000	₩ 188,754,000,000
Stage 1
Reconciliation of changes in provisions for payment guarantee [Abstract]
Beginning balance	[1]	47,132,000,000
Changes in provisions for payment guarantee [Abstract]
Replaced by 12-month expected credit loss		76,000,000
Replaced with expected credit loss for the entire period		(954,000,000)
Replaced with credit-impaired financial assets		(21,000,000)
Provisions used		(8,506,000,000)
Unused provision reversed provisions for payment guarantee		(4,873,000,000)
Others		9,393,000,000
Ending balance		42,247,000,000
Stage 2
Reconciliation of changes in provisions for payment guarantee [Abstract]
Beginning balance	[1]	18,281,000,000
Changes in provisions for payment guarantee [Abstract]
Replaced by 12-month expected credit loss		(76,000,000)
Replaced with expected credit loss for the entire period		58,894,000,000
Replaced with credit-impaired financial assets		(20,000,000)
Provisions used		0
Unused provision reversed provisions for payment guarantee		(46,344,000,000)
Others		6,000,000
Ending balance		30,741,000,000
Stage 3
Reconciliation of changes in provisions for payment guarantee [Abstract]
Beginning balance	[1]	127,511,000,000
Changes in provisions for payment guarantee [Abstract]
Replaced by 12-month expected credit loss		0
Replaced with expected credit loss for the entire period		(57,940,000,000)
Replaced with credit-impaired financial assets		41,000,000
Provisions used		0
Unused provision reversed provisions for payment guarantee		(35,773,000,000)
Others		0
Ending balance		₩ 33,839,000,000
[1]	The beginning balance was restated in accordance with IFRS 9.

Provisions_Details of provis193

Provisions_Details of provisions for unused commitment (Details) - KRW (₩)		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
Reconciliation of changes in provisions for credit commitment [Abstract]
Beginning balance	[1]	₩ 104,985,000,000
Beginning balance		66,115,000,000	₩ 87,909,000,000
Changes in provisions for credit commitment [Abstract]
Replaced by 12-month expected credit loss		0
Replaced with expected credit loss for the entire period		0
Replaced with credit-impaired financial assets		0
Provisions provided			491,000,000
Provisions used			(42,000,000)
Net reversal of unused amount		(3,155,000,000)	(5,736,000,000)
Foreign currencies translation adjustments			(1,000,000)
Others		44,000,000
Ending balance		101,874,000,000	₩ 82,621,000,000
Stage 1
Reconciliation of changes in provisions for credit commitment [Abstract]
Beginning balance	[1]	75,232,000,000
Changes in provisions for credit commitment [Abstract]
Replaced by 12-month expected credit loss		6,262,000,000
Replaced with expected credit loss for the entire period		(2,543,000,000)
Replaced with credit-impaired financial assets		(159,000,000)
Net reversal of unused amount		(6,183,000,000)
Others		44,000,000
Ending balance		72,653,000,000
Stage 2
Reconciliation of changes in provisions for credit commitment [Abstract]
Beginning balance	[1]	27,875,000,000
Changes in provisions for credit commitment [Abstract]
Replaced by 12-month expected credit loss		(6,145,000,000)
Replaced with expected credit loss for the entire period		2,614,000,000
Replaced with credit-impaired financial assets		(325,000,000)
Net reversal of unused amount		3,356,000,000
Others		0
Ending balance		27,375,000,000
Stage 3
Reconciliation of changes in provisions for credit commitment [Abstract]
Beginning balance	[1]	1,878,000,000
Changes in provisions for credit commitment [Abstract]
Replaced by 12-month expected credit loss		(117,000,000)
Replaced with expected credit loss for the entire period		(71,000,000)
Replaced with credit-impaired financial assets		484,000,000
Net reversal of unused amount		(328,000,000)
Others		0
Ending balance		₩ 1,846,000,000
[1]	The beginning balance was restated in accordance with IFRS 9.

Provisions_Changes in asset ret

Provisions_Changes in asset retirement obligation (Details) - KRW (₩) ₩ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Reconciliation of changes in provision for decommissioning restoration and rehabilitation costs [Abstract]
Beginning balance	₩ 61,872	₩ 58,076
Changes in provision for decommissioning restoration and rehabilitation costs [Abstract]
Provisions provided	1,083	654
Provisions used	(295)	(416)
Reversal of provisions unused	(993)	(727)
Amortization	259	203
Increase in restoration costs and others	5,532	4,163
Ending balance	₩ 67,458	₩ 61,953
Description of nature of obligation, other provisions	The amount of the asset retirement obligation is the present value of the best estimate of future expected recovery cost arising from leased premises as of June 30, 2018, discounted by appropriate discount rate.
Description of expected timing of outflows, other provisions	The expenditure of the recovery cost is expected to occur by the end of each premise’s lease period, and the Group has used average lease period of each category of leases terminated during the past years in order to rationally estimate the lease period.
Description of major assumptions made concerning future events, other provisions	In addition, the Group used average amount of actual recovery cost for the past 3 years and the average inflation rate for last year in order to estimate future recovery cost.

Provisions_Changes in other pro

Provisions_Changes in other provisions (Details) - KRW (₩)	6 Months Ended
	Jun. 30, 2018		Jun. 30, 2017
Other provisions except for provision for decommissioning restoration and rehabilitation costs [Member]
Reconciliation of changes in other provisions [Abstract]
Beginning balance	₩ 99,236,000,000		₩ 44,375,000,000
Changes in other provisions [Abstract]
Provisions provided	38,280,000,000		34,598,000,000
Provisions used	(51,090,000,000)		(48,415,000,000)
Reversal of provisions unused	(40,000,000)		(40,000,000)
Foreign currencies translation adjustments	(7,000,000)		(146,000,000)
Transfer	5,467,000,000	[1]	11,482,000,000	[2]
Amortization			53,000,000
Others	18,369,000,000		5,795,000,000
Ending balance	110,215,000,000		47,702,000,000
Provisions for customer reward credits
Reconciliation of changes in other provisions [Abstract]
Beginning balance	40,445,000,000		22,093,000,000
Changes in other provisions [Abstract]
Provisions provided	36,044,000,000		32,208,000,000
Provisions used	(48,891,000,000)		(39,402,000,000)
Reversal of provisions unused	0		0
Foreign currencies translation adjustments	0		0
Transfer	5,467,000,000	[1]	11,482,000,000	[2]
Amortization			0
Others	13,670,000,000		5,667,000,000
Ending balance	₩ 46,735,000,000		₩ 32,048,000,000
Explanation of increase (decrease) through transfer other provisions	As the credits of the affiliates were transferred to the Group, the allowance for the provisions for customer reward credits increased for the three months ended March 31, 2018.		As the credits of the affiliates were transferred to the Group, the allowance for the provisions for customer reward credits increased for the six months ended June 30, 2017.
Other provisions
Reconciliation of changes in other provisions [Abstract]
Beginning balance	₩ 58,791,000,000		₩ 22,282,000,000
Changes in other provisions [Abstract]
Provisions provided	2,236,000,000		2,390,000,000
Provisions used	(2,199,000,000)		(9,013,000,000)
Reversal of provisions unused	(40,000,000)		(40,000,000)
Foreign currencies translation adjustments	(7,000,000)		(146,000,000)
Transfer	0		0
Amortization			53,000,000
Others	4,699,000,000		128,000,000
Ending balance	₩ 63,480,000,000		₩ 15,654,000,000
[1]	As the credits of the affiliates were transferred to the Group, the allowance for the provisions for customer reward credits increased for the six months ended June 30, 2018.
[2]	As the credits of the affiliates were transferred to the Group, the allowance for the provisions for customer reward credits increased for the six months ended June 30, 2017.

Net defined benefits liability_

Net defined benefits liability_Details of net defined benefit liability (Details) - KRW (₩) ₩ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Disclosure of defined benefit plans [Abstract]
Description of type of retirement benefit plan	Employees and directors with one or more years of service are entitled to receive a payment upon termination of their employment, based on their length of service and rate of pay at the time of termination.	Employees and directors with one or more years of service are entitled to receive a payment upon termination of their employment, based on their length of service and rate of pay at the time of termination.
Description of nature of benefits provided by plan	The assets of the plans are measured at their fair value at the end of reporting date.	The assets of the plans are measured at their fair value at the end of reporting date.
Description of significant actuarial assumptions made and method used to calculate actuarial present value of promised retirement benefits	The plan liabilities are measured using the projected unit method, which takes account of projected earnings increases, using actuarial assumptions that give the best estimate of the future cash flows that will arise under the plan liabilities.	The plan liabilities are measured using the projected unit method, which takes account of projected earnings increases, using actuarial assumptions that give the best estimate of the future cash flows that will arise under the plan liabilities.
Description of risks to which plan exposes entity	The Group is exposed to various risks through defined benefit retirement pension plan, and the most significant risks are as follows: -Volatility of asset:The defined benefit obligation was estimated with an interest rate calculated based on blue chip corporate bonds earnings. A deficit may occur if the rate of return of plan assets falls short of the interest rate. -Decrease in profitability of blue chip bonds:A decrease in profitability of blue chip bonds will be offset by some increase in the value of debt securities that the employee benefit plan owns but will bring an increase in the defined benefit obligation. -Risk of inflation:Defined benefit obligations are related to inflation rate; the higher the inflation rate is, the higher the level of liabilities. Therefore, deficit occurs in the system if an inflation rate increases.	The Group is exposed to various risks through defined benefit retirement pension plan, and the most significant risks are as follows: -Volatility of asset:The defined benefit obligation was estimated with an interest rate calculated based on blue chip corporate bonds earnings. A deficit may occur if the rate of return of plan assets falls short of the interest rate. -Decrease in profitability of blue chip bonds:A decrease in profitability of blue chip bonds will be offset by some increase in the value of debt securities that the employee benefit plan owns but will bring an increase in the defined benefit obligation. -Risk of inflation:Defined benefit obligations are related to inflation rate; the higher the inflation rate is, the higher the level of liabilities. Therefore, deficit occurs in the system if an inflation rate increases.
Surplus deficit in plan [Abstract]
Defined benefit obligation	₩ 1,175,786		₩ 1,071,170
Fair value of plan assets	(1,075,927)		(1,027,906)
Net defined benefit liability (asset)	₩ 99,859		₩ 43,264

Net defined benefits liabili197

Net defined benefits liability_Changes in the carrying value of defined benefit obligation and the plan assets (Details) - KRW (₩)		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
Disclosure of net defined benefit liability asset [Line Items]
Beginning balance		₩ 43,264,000,000
Changes in net defined benefit liability asset [Abstract]
Current service cost		(72,460,000,000)	₩ (73,564,000,000)
Interest expense(income)		(829,000,000)	(1,983,000,000)
Remeasurements	[1]	(81,462,000,000)	(12,486,000,000)
Curtailment or settlement		0	(321,000,000)
Ending balance		99,859,000,000
Present value of defined benefit obligation
Disclosure of net defined benefit liability asset [Line Items]
Beginning balance		1,071,170,000,000	984,381,000,000
Changes in net defined benefit liability asset [Abstract]
Current service cost		72,460,000,000	73,564,000,000
Interest expense(income)		15,797,000,000	13,144,000,000
Remeasurements		72,374,000,000	4,639,000,000
Foreign currencies translation adjustments		8,000,000	(121,000,000)
Retirement benefit paid		(57,109,000,000)	(31,022,000,000)
Curtailment or settlement		0	(10,076,000,000)
Others		1,086,000,000	127,000,000
Ending balance		1,175,786,000,000	1,034,636,000,000
Fair value of plan assets
Disclosure of net defined benefit liability asset [Line Items]
Beginning balance		1,027,906,000,000	990,653,000,000
Changes in net defined benefit liability asset [Abstract]
Interest expense(income)		16,626,000,000	15,127,000,000
Remeasurements		(9,088,000,000)	(7,847,000,000)
Employer’s contributions		96,273,000,000	18,000,000,000
Retirement benefit paid		(55,790,000,000)	(29,431,000,000)
Curtailment or settlement		0	(10,396,000,000)
Others		0	43,113,000,000
Ending balance		₩ 1,075,927,000,000	₩ 1,019,219,000,000
[1]	This is an amount before considering the tax effects.

Net defined benefits liabili198

Net defined benefits liability_Fair value of plan assets (Details) - KRW (₩) ₩ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Disclosure of fair value of plan assets [Abstract]
Return on plan assets, net defined benefit liability (asset)	₩ 7,538	₩ 7,280
Estimate of contributions expected to be paid to plan	₩ 125,818

Net defined benefits liabili199

Net defined benefits liability_Current service cost net interest expense income past service cost loss gain on the curtailment or settlement and loss gain due to remeasurements (Details) - KRW (₩)		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
Postemployment benefit expense defined benefit plans [Abstract]
Current service cost		₩ 72,460,000,000	₩ 73,564,000,000
Net interest income		(829,000,000)	(1,983,000,000)
Gain (loss) on the curtailment or settlement		0	321,000,000
Cost recognized in net income		71,631,000,000	71,902,000,000
Remeasurements	[1]	81,462,000,000	12,486,000,000
Cost recognized in total comprehensive income		153,093,000,000	84,388,000,000
Retirement benefit service costs defined contribution plans		₩ 1,304,000,000	₩ 2,155,000,000
[1]	This is an amount before considering the tax effects.

Net defined benefits liabili200

Net defined benefits liability_Key actuarial assumptions used in defined benefit liability assessment (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Disclosure of actuarial assumptions [Abstract]
Discount rate	3.25%	3.18%
Future wage growth rate	6.18%	6.18%
Mortality rate	Issued by Korea Insurance Development Institute	Issued by Korea Insurance Development Institute
Retirement rate	Experience rate for each employment classification	Experience rate for each employment classification
Weighted average maturity of defined benefit liability	12.94

Net defined benefits liabili201

Net defined benefits liability_Sensitivity to actuarial assumptions used in the assessment of defined benefit obligation (Details) - KRW (₩) ₩ in Millions	Jun. 30, 2018	Dec. 31, 2017
Discount rate | Increase by 1% point
Disclosure of sensitivity analysis for actuarial assumptions [Line Items]
Increase decrease in defined benefit obligation due to reasonably possible increase in actuarial assumption	₩ (124,157)	₩ (116,405)
Discount rate | Decrease by 1% point
Disclosure of sensitivity analysis for actuarial assumptions [Line Items]
Increase decrease in defined benefit obligation due to reasonably possible decrease in actuarial assumption	146,273	137,151
Future wage growth rate | Increase by 1% point
Disclosure of sensitivity analysis for actuarial assumptions [Line Items]
Increase decrease in defined benefit obligation due to reasonably possible increase in actuarial assumption	145,794	136,707
Future wage growth rate | Decrease by 1% point
Disclosure of sensitivity analysis for actuarial assumptions [Line Items]
Increase decrease in defined benefit obligation due to reasonably possible decrease in actuarial assumption	₩ (125,567)	₩ (117,765)

Other financial liabilities 202

Other financial liabilities and other liabilities_Details of other financial liabilities and other liabilities (Details) $ in Thousands, ₩ in Millions	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Other financial liabilities and other liabilities [Line Items]
Total of other financial liabilities	₩ 21,408,267	$ 19,255,502	₩ 13,892,461
Other liabilities	302,913	$ 272,453	283,981
Total of other financial liabilities and other liabilities	21,711,180		14,176,442
Present value discount
Other financial liabilities and other liabilities [Line Items]
Total of other financial liabilities	(2,396)		(1,597)
Account payables | Gross carrying amount [Member]
Other financial liabilities and other liabilities [Line Items]
Total of other financial liabilities	9,021,786		4,692,320
Accrued expenses | Gross carrying amount [Member]
Other financial liabilities and other liabilities [Line Items]
Total of other financial liabilities	1,809,499		2,049,861
Borrowings from trust accounts | Gross carrying amount [Member]
Other financial liabilities and other liabilities [Line Items]
Total of other financial liabilities	3,999,899		3,271,817
Agency business revenue | Gross carrying amount [Member]
Other financial liabilities and other liabilities [Line Items]
Total of other financial liabilities	258,497		344,591
Domestic exchange payables | Gross carrying amount [Member]
Other financial liabilities and other liabilities [Line Items]
Total of other financial liabilities	4,229,125		590,667
Foreign exchange payables | Gross carrying amount [Member]
Other financial liabilities and other liabilities [Line Items]
Total of other financial liabilities	604,344		1,309,646
Other miscellaneous financial liabilities | Gross carrying amount [Member]
Other financial liabilities and other liabilities [Line Items]
Total of other financial liabilities	1,487,513		1,635,156
Unearned Income | Gross carrying amount [Member]
Other financial liabilities and other liabilities [Line Items]
Other liabilities	178,799		180,664
Other miscellaneous liabilities | Gross carrying amount [Member]
Other financial liabilities and other liabilities [Line Items]
Other liabilities	₩ 124,114		₩ 103,317

Derivatives_Details of derivati

Derivatives_Details of derivative assets and derivative liabilities (Details) $ in Thousands	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	₩ 299,701,576,000,000		₩ 268,733,330,000,000
Derivative assets for hedging	12,395,000,000	$ 11,149	59,272,000,000
Derivative assets for trading	2,391,211,000,000		3,115,775,000,000
Derivative liabilities for hedging	67,505,000,000	$ 60,717	67,754,000,000
Derivative liabilities for trading	2,377,750,000,000		3,150,149,000,000
For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	12,395,000,000		59,272,000,000
Derivative liabilities for hedging	34,540,000,000		12,103,000,000
For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	32,965,000,000		55,651,000,000
For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	2,391,211,000,000		3,115,775,000,000
Derivative liabilities for trading	2,377,750,000,000		3,150,149,000,000
Interest rate futures
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	272,778,000,000		75,845,000,000
Interest rate futures | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Interest rate futures | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Interest rate futures | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	0		0
Derivative liabilities for trading	0		0
Interest rate swap
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	143,307,983,000,000		130,197,378,000,000
Interest rate swap | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	12,395,000,000		59,272,000,000
Derivative liabilities for hedging	34,540,000,000		12,103,000,000
Interest rate swap | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Interest rate swap | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	218,551,000,000		223,935,000,000
Derivative liabilities for trading	232,719,000,000		253,972,000,000
Interest rate options | Long [Member]
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	660,000,000,000		630,000,000,000
Interest rate options | Long [Member] | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Interest rate options | Long [Member] | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Interest rate options | Long [Member] | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	10,897,000,000		12,346,000,000
Derivative liabilities for trading	0		0
Interest rate options | Short [Member]
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	785,000,000,000		795,000,000,000
Interest rate options | Short [Member] | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Interest rate options | Short [Member] | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Interest rate options | Short [Member] | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	0		0
Derivative liabilities for trading	11,731,000,000		12,869,000,000
Currency futures
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	371,529,000,000		318,217,000,000
Currency futures | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Currency futures | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Currency futures | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	0		0
Derivative liabilities for trading	0		0
Currency forward
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	80,082,126,000,000		72,526,956,000,000
Currency forward | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Currency forward | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Currency forward | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	1,200,200,000,000		1,314,368,000,000
Derivative liabilities for trading	1,164,623,000,000		1,375,799,000,000
Currency swap
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	56,427,354,000,000		48,176,306,000,000
Currency swap | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Currency swap | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	32,965,000,000		55,651,000,000
Currency swap | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	806,790,000,000		1,352,924,000,000
Derivative liabilities for trading	750,377,000,000		1,347,905,000,000
Currency option | Long [Member]
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	2,635,551,000,000		2,291,154,000,000
Currency option | Long [Member] | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Currency option | Long [Member] | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Currency option | Long [Member] | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	36,079,000,000		64,267,000,000
Derivative liabilities for trading	0		0
Currency option | Short [Member]
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	4,651,496,000,000		4,038,237,000,000
Currency option | Short [Member] | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Currency option | Short [Member] | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Currency option | Short [Member] | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	0		0
Derivative liabilities for trading	49,352,000,000		58,687,000,000
Equity futures
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	124,009,000,000		91,436,000,000
Equity futures | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Equity futures | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Equity futures | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	0		0
Derivative liabilities for trading	0		0
Equity swap
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	435,790,000,000		15,000,000,000
Equity swap | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Equity swap | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Equity swap | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	3,021,000,000		103,000,000
Derivative liabilities for trading	4,542,000,000		10,000,000
Equity option | Long [Member]
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	4,272,150,000,000		5,060,706,000,000
Equity option | Long [Member] | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Equity option | Long [Member] | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Equity option | Long [Member] | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	115,210,000,000		146,775,000,000
Derivative liabilities for trading	0		0
Equity option | Short [Member]
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	5,661,146,000,000		4,504,290,000,000
Equity option | Short [Member] | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Equity option | Short [Member] | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Equity option | Short [Member] | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	0		0
Derivative liabilities for trading	163,966,000,000		99,770,000,000
Other futures
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	965,000,000		0
Other futures | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Other futures | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Other futures | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	0		0
Derivative liabilities for trading	0		0
Other forward
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	5,618,000,000
Other forward | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0
Derivative liabilities for hedging	0
Other forward | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0
Other forward | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	0
Derivative liabilities for trading	0
Other swap
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount	8,081,000,000		7,805,000,000
Other swap | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging	0		0
Derivative liabilities for hedging	0		0
Other swap | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging	0		0
Other swap | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading	463,000,000		1,057,000,000
Derivative liabilities for trading	₩ 440,000,000		1,037,000,000
Other option | Long [Member]
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount			0
Other option | Long [Member] | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging			0
Derivative liabilities for hedging			0
Other option | Long [Member] | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging			0
Other option | Long [Member] | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading			0
Derivative liabilities for trading			0
Other option | Short [Member]
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount			5,000,000,000
Other option | Short [Member] | For fair value hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for hedging			0
Derivative liabilities for hedging			0
Other option | Short [Member] | For cash flow hedging
Disclosure of detailed information about hedging instruments [Line Items]
Derivative liabilities for hedging			0
Other option | Short [Member] | For trading
Disclosure of detailed information about hedging instruments [Line Items]
Derivative assets for trading			0
Derivative liabilities for trading			₩ 100,000,000

Derivatives_Overview of the Gro

Derivatives_Overview of the Group's hedge accounting (Details)	6 Months Ended
	Jun. 30, 2018
Fair value hedges [Member]
Disclosure of detailed information about hedges [Line Items]
Description of type of hedge	As of the current period end, the Group has applied fair value hedge on fixed interest rate foreign currency denominated debentures amounting to 3,150,145 million Won. The purpose of the hedging is to avoid fair value volatility risk of fixed interest rate foreign currency denominated debentures derived from fluctuations of market interest rate, and as such the Group entered into interest rate swap agreements designated as hedging instruments.
Description of financial instruments designated as hedging instruments	The Group entered into interest rate swap agreements to manage its exposure to interest rate risk and designated as hedging instruments. Pursuant to the interest rate swap agreement, hedge ratio is determined by matching the nominal value to the face value of the hedging instrument. The fair value of the interest rate swap at the end of the reporting period is determined by discounting future cash flows estimated using the yield curve at the end of the reporting period and the credit risk embedded in the contract and the average interest rate is determined based on the outstanding balance at the end of the reporting period. The variable interest rate applied to the interest rate swap is USD Libor 3M (6M) plus spread. In accordance with the terms of each interest rate swap contract designated as a hedging instrument, the Group receives interest at a fixed interest rate and pays interest at a variable interest rate. The interest rate swap agreements and the hedged items are subject to fluctuations in the underlying market rate of interest and the Group expects the value of the interest rate swap contract and the value of the hedged item to generally change in the opposite direction.
Description of nature of risks being hedged	In this hedging relationship, only the market interest rate fluctuation, which is the most significant part of the fair value change of the hedged item, is designated as the hedged risk, and other risk factors including credit risk are not included in the hedged risk. Therefore, the ineffective portion of the hedge could arise from fluctuations in the timing of the cash flow of the hedged item, the change in the total amount and price of the hedged item, or significant credit risk fluctuation of either party of the hedged item.
Cash flow hedges [Member]
Disclosure of detailed information about hedges [Line Items]
Description of type of hedge	As of the current period end, the Group has applied Cash Flow hedge on foreign currency denominated bonds amounting to 724,487 million Won.
Description of financial instruments designated as hedging instruments	The Group has designated foreign currency swap contracts as hedging instruments in order to achieve such objectives.
Description of nature of risks being hedged	The Group’s objectives of hedging are to ① Mitigate risks of cash flow fluctuation from principal and interest of variable interest rate debentures denominated in foreign currency, which arise from changes in foreign exchange rate and market interest rate; and ② Mitigate the risks of cash flow fluctuation from principal and interest of fixed-interest rate debentures denominated in foreign currency, which arise from changes in foreign exchange rates.

Derivatives_The nominal amounts

Derivatives_The nominal amounts and the average interest and currency rate of hedging instrument (Details)	6 Months Ended
	Jun. 30, 2018USD ($)SGD ($)
For fair value hedging | Interest rate risk | Interest rate swaps
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [Line Items]
Nominal amount of hedging instrument	2,850,000,000
Description of average rate of interest rate risk hedging instrument	Fixed 3.98% receipt and 3.96% floating paid
For fair value hedging | Interest rate risk | Interest rate swaps | Less than 1 year
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [Line Items]
Nominal amount of hedging instrument	500,000,000
For fair value hedging | Interest rate risk | Interest rate swaps | 1 to 5 years
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [Line Items]
Nominal amount of hedging instrument	1,350,000,000
For fair value hedging | Interest rate risk | Interest rate swaps | Over 5 years
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [Line Items]
Nominal amount of hedging instrument	1,000,000,000
For cash flow hedging | Foreign currencies translation risk and interest rate risk | Currency swap
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [Line Items]
Nominal amount of hedging instrument	500,000,000
Description of average rate of currency risk hedging instrument	USD 2.65% receipt, KRW 1.71% paid, USD/KRW =1,173 Won
For cash flow hedging | Foreign currencies translation risk and interest rate risk | Currency swap | Less than 1 year
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [Line Items]
Nominal amount of hedging instrument	50,000,000
For cash flow hedging | Foreign currencies translation risk and interest rate risk | Currency swap | 1 to 5 years
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [Line Items]
Nominal amount of hedging instrument	450,000,000
For cash flow hedging | Foreign currencies translation risk and interest rate risk | Currency swap | Over 5 years
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [Line Items]
Nominal amount of hedging instrument	0
For cash flow hedging | Foreign currencies translation risk | Currency swap
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [Line Items]
Nominal amount of hedging instrument	204,000,000
Description of average rate of currency risk hedging instrument	SGD 1.91% receipt, KRW 1.98% paid, SGD/KRW = 828 Won
For cash flow hedging | Foreign currencies translation risk | Currency swap | Less than 1 year
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [Line Items]
Nominal amount of hedging instrument	0
For cash flow hedging | Foreign currencies translation risk | Currency swap | 1 to 5 years
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [Line Items]
Nominal amount of hedging instrument	204,000,000
For cash flow hedging | Foreign currencies translation risk | Currency swap | Over 5 years
Disclosure of information about terms and conditions of hedging instruments and how they affect future cash flows [Line Items]
Nominal amount of hedging instrument	0

Derivatives_Amounts related to

Derivatives_Amounts related to items designated as hedging instruments (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)USD ($)SGD ($)
For fair value hedging | Interest rate risk
Disclosure of detailed information about hedging instruments [Line Items]
Description of line item in statement of financial position that includes hedging instrument	Derivative assets, Derivative liabilities
For fair value hedging | Interest rate risk | Interest rate swaps
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount of hedging instrument | $	2,850,000,000
Hedging instrument, assets	₩ 12,395,000,000
Hedging instrument, liabilities	34,540,000,000
Gain (loss) on change in fair value of hedging instrument used as basis for recognising hedge ineffectiveness	₩ (62,246,000,000)
For cash flow hedging | Foreign currencies translation risk and interest rate risk
Disclosure of detailed information about hedging instruments [Line Items]
Description of line item in statement of financial position that includes hedging instrument	Derivative liabilities
For cash flow hedging | Foreign currencies translation risk and interest rate risk | Currency swap
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount of hedging instrument | $	500,000,000
Hedging instrument, assets	₩ 0
Hedging instrument, liabilities	27,594,000,000
Gain (loss) on change in fair value of hedging instrument used as basis for recognising hedge ineffectiveness	₩ 22,013,000,000
For cash flow hedging | Foreign currencies translation risk
Disclosure of detailed information about hedging instruments [Line Items]
Description of line item in statement of financial position that includes hedging instrument	Derivative liabilities
For cash flow hedging | Foreign currencies translation risk | Currency swap
Disclosure of detailed information about hedging instruments [Line Items]
Nominal amount of hedging instrument | $	204,000,000
Hedging instrument, assets	₩ 0
Hedging instrument, liabilities	5,372,000,000
Gain (loss) on change in fair value of hedging instrument used as basis for recognising hedge ineffectiveness	₩ 672,000,000

Derivatives_Carrying amounts of

Derivatives_Carrying amounts of hedged item and amount of hedge adjustments due to hedge accounting (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)
For fair value hedging | Interest rate risk
Disclosure of detailed information about hedged items [Line Items]
Hedged item, assets	₩ 0
Hedged item, liabilities	3,150,145,000,000
Accumulated fair value hedge adjustment on hedged item included in carrying amount, assets	0
Accumulated fair value hedge adjustment on hedged item included in carrying amount, liabilities	₩ 60,732,000,000
Line item in the statement of financial position in which the hedged item is included	Debentures
Changing in fair value used for calculating hedge ineffectiveness	₩ 66,455,000,000
Reserve of cash flow hedges, hedging relationships for which hedge accounting is no longer applied	0
For cash flow hedging | Foreign currencies translation risk and interest rate risk
Disclosure of detailed information about hedged items [Line Items]
Hedged item, assets	0
Hedged item, liabilities	558,258,000,000
Accumulated fair value hedge adjustment on hedged item included in carrying amount, assets	0
Accumulated fair value hedge adjustment on hedged item included in carrying amount, liabilities	₩ 0
Line item in the statement of financial position in which the hedged item is included	Debentures
Changing in fair value used for calculating hedge ineffectiveness	₩ (21,725,000,000)
Reserve of cash flow hedges, hedging relationships for which hedge accounting is no longer applied	(1,665,000,000)	[1]
For cash flow hedging | Foreign currencies translation risk
Disclosure of detailed information about hedged items [Line Items]
Hedged item, assets	0
Hedged item, liabilities	166,229,000,000
Accumulated fair value hedge adjustment on hedged item included in carrying amount, assets	0
Accumulated fair value hedge adjustment on hedged item included in carrying amount, liabilities	₩ 0
Line item in the statement of financial position in which the hedged item is included	Debentures
Changing in fair value used for calculating hedge ineffectiveness	₩ (505,000,000)
Reserve of cash flow hedges, hedging relationships for which hedge accounting is no longer applied	₩ (3,770,000,000)	[1]
[1]	Amount after tax deduction

Derivatives_Amounts recognized

Derivatives_Amounts recognized in profit or loss due to the ineffective portion of fair value hedge (Details)	6 Months Ended
	Jun. 30, 2018KRW (₩)
For fair value hedging | Interest rate risk
Disclosure of information about amounts that affected statement of comprehensive income as result of hedge accounting [Line Items]
Changes in the value of hedging instruments recognized in cash flow hedge reserve	₩ 0
Hedge ineffectiveness recognized in profit or loss	₩ 4,209,000,000
Line item in the profit or loss that includes hedge ineffectiveness	Other net operating income
Amounts reclassified from cash flow hedge reserve to profit or loss	₩ 0
For cash flow hedging | Foreign currencies translation risk and interest rate risk
Disclosure of information about amounts that affected statement of comprehensive income as result of hedge accounting [Line Items]
Changes in the value of hedging instruments recognized in cash flow hedge reserve	22,043,000,000
Hedge ineffectiveness recognized in profit or loss	₩ (30,000,000)
Line item in the profit or loss that includes hedge ineffectiveness	Other net operating expense
Amounts reclassified from cash flow hedge reserve to profit or loss	₩ 25,049,000,000
Line item affected in profit or loss because of the reclassification	Other net operating income
For cash flow hedging | Foreign currencies translation risk
Disclosure of information about amounts that affected statement of comprehensive income as result of hedge accounting [Line Items]
Changes in the value of hedging instruments recognized in cash flow hedge reserve	₩ 672,000,000
Hedge ineffectiveness recognized in profit or loss	₩ 0
Line item in the profit or loss that includes hedge ineffectiveness	Other net operating income
Amounts reclassified from cash flow hedge reserve to profit or loss	₩ 3,894,000,000
Line item affected in profit or loss because of the reclassification	Other net operating income

Deferred day 1 profits or losse

Deferred day 1 profits or losses_Changes of deferred day 1 profits or losses (Details) - KRW (₩) ₩ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Reconciliation of aggregate difference between fair value at initial recognition and amount determined using valuation technique yet to be recognised [Abstract]
Beginning balance	₩ 7,416	₩ 13,422
Changes in aggregate difference between fair value at initial recognition and amount determined using valuation technique yet to be recognised [Abstract]
New transactions	20,820	500
Amounts recognized in losses	(3,000)	(3,613)
Ending balance	₩ 25,236	₩ 10,309
Description of accounting policy for recognising difference between fair value at initial recognition and amount determined using valuation technique	In case some variables to measure fair values of financial instruments are not observable or available in the market, valuation techniques are utilized to evaluate such financial instruments. Those financial instruments are recorded at the fair value produced by the valuation techniques as at the time of acquisition, even though there are difference noted between the transaction price and the fair value. The table above presents the difference yet to be realized as profit or losses.	In case some variables to measure fair values of financial instruments are not observable or available in the market, valuation techniques are utilized to evaluate such financial instruments. Those financial instruments are recorded at the fair value produced by the valuation techniques as at the time of acquisition, even though there are difference noted between the transaction price and the fair value. The table above presents the difference yet to be realized as profit or losses.

Capital stock and capital su210

Capital stock and capital surplus_Details of share capital (Details) ₩ / shares in Units, $ in Thousands, ₩ in Millions	6 Months Ended
	Jun. 30, 2018KRW (₩)₩ / sharesshares	Jun. 30, 2017	Jun. 30, 2018USD ($)shares	Dec. 31, 2017KRW (₩)₩ / sharesshares
Disclosure of classes of share capital [Line Items]
Shares of common stock authorized	5,000,000,000		5,000,000,000	5,000,000,000
Par value | ₩ / shares	₩ 5,000			₩ 5,000
Shares of common stock issued	676,000,000		676,000,000	676,000,000
Capital stock	₩ 3,381,392		$ 3,041,367	₩ 3,381,392
Description Of changes in numbers of issued shares of common stock	There is no change to be disclosed in numbers of issued and outstanding shares of common stock for the six months ended June, 2018 and 2017.	There is no change to be disclosed in numbers of issued and outstanding shares of common stock for the six months ended June, 2018 and 2017.

Capital stock and capital su211

Capital stock and capital surplus_Details of capital surplus (Details) $ in Thousands, ₩ in Millions	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)
Miscellaneous equity [Abstract]
Capital in excess of par value	₩ 269,533		₩ 269,533
Other capital surplus	16,352		16,347
Total	₩ 285,885	$ 257,137	₩ 285,880

Hybrid securities_Details of hy

Hybrid securities_Details of hybrid securities classified as owners equity (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2018KRW (₩)	Dec. 31, 2017KRW (₩)	Jun. 30, 2018USD ($)
Disclosure of bond type hybrid securities of other equity interest classified as owner’ s equity [Line Items]
Hybrid securities	₩ 2,763,256,000,000	₩ 3,017,888,000,000	$ 2,485,389
Description of nature of bond type hybrid securities of other equity interest classified as owners equity	The hybrid securities mentioned above are either without a maturity date or its maturity can be extended indefinitely at the maturity date without change of terms. Further, if a resolution is passed not to pay dividends on common stock, interest payments on the hybrid securities may be not occur	The hybrid securities mentioned above are either without a maturity date or its maturity can be extended indefinitely at the maturity date without change of terms. Further, if a resolution is passed not to pay dividends on common stock, interest payments on the hybrid securities may be not occur
Hybrid securities of other equity interest in local currency issued in 200801
Disclosure of bond type hybrid securities of other equity interest classified as owner’ s equity [Line Items]
Issue date		Jun. 20, 2008
Maturity		Jun. 20, 2038
Interest rate (%)		7.70%
Hybrid securities	₩ 0	₩ 255,000,000,000
Hybrid securities of other equity interest in local currency issued in 201301
Disclosure of bond type hybrid securities of other equity interest classified as owner’ s equity [Line Items]
Issue date	Apr. 25, 2013	Apr. 25, 2013
Maturity	Apr. 25, 2043	Apr. 25, 2043
Interest rate (%)	4.40%	4.40%
Hybrid securities	₩ 500,000,000,000	₩ 500,000,000,000
Hybrid securities of other equity interest in local currency issued in 201302
Disclosure of bond type hybrid securities of other equity interest classified as owner’ s equity [Line Items]
Issue date	Nov. 13, 2013	Nov. 13, 2013
Maturity	Nov. 13, 2043	Nov. 13, 2043
Interest rate (%)	5.70%	5.70%
Hybrid securities	₩ 200,000,000,000	₩ 200,000,000,000
Hybrid securities of other equity interest in local currency issued in 201401
Disclosure of bond type hybrid securities of other equity interest classified as owner’ s equity [Line Items]
Issue date	Dec. 12, 2014	Dec. 12, 2014
Maturity	Dec. 12, 2044	Dec. 12, 2044
Interest rate (%)	5.20%	5.20%
Hybrid securities	₩ 160,000,000,000	₩ 160,000,000,000
Hybrid securities of other equity interest in local currency issued in 201501
Disclosure of bond type hybrid securities of other equity interest classified as owner’ s equity [Line Items]
Issue date	Jun. 3, 2015	Jun. 3, 2015
Maturity	Jun. 3, 2045	Jun. 3, 2045
Interest rate (%)	4.40%	4.40%
Hybrid securities	₩ 240,000,000,000	₩ 240,000,000,000
Hybrid securities of other equity interest in foreign currency issued in 201501
Disclosure of bond type hybrid securities of other equity interest classified as owner’ s equity [Line Items]
Issue date	Jun. 10, 2015	Jun. 10, 2015
Maturity	Jun. 10, 2045	Jun. 10, 2045
Interest rate (%)	5.00%	5.00%
Hybrid securities	₩ 559,650,000,000	₩ 559,650,000,000
Hybrid securities of other equity interest in foreign currency issued in 201601
Disclosure of bond type hybrid securities of other equity interest classified as owner’ s equity [Line Items]
Issue date	Sep. 27, 2016	Sep. 27, 2016
Interest rate (%)	4.50%	4.50%
Hybrid securities	₩ 553,450,000,000	₩ 553,450,000,000
Hybrid securities of other equity interest in foreign currency issued in 201701
Disclosure of bond type hybrid securities of other equity interest classified as owner’ s equity [Line Items]
Issue date	May 16, 2017	May 16, 2017
Interest rate (%)	5.30%	5.30%
Hybrid securities	₩ 562,700,000,000	₩ 562,700,000,000
Issuance cost
Disclosure of bond type hybrid securities of other equity interest classified as owner’ s equity [Line Items]
Hybrid securities	₩ (12,544,000,000)	₩ (12,912,000,000)

Other equity_Details of other e

Other equity_Details of other equity (Details) $ in Thousands	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Dec. 31, 2017KRW (₩)	Jun. 30, 2017KRW (₩)	Dec. 31, 2016KRW (₩)
Accumulated other comprehensive income [Abstract]
Net gain or loss on valuation of financial assets at FVTOCI	₩ (46,746,000,000)		₩ 0
Gain on valuation of AFS financial assets	0		301,930,000,000
Gain(loss) on financial liabilities at fair value through profit or loss designated as upon initial recognition due to own credit risk	29,000,000		0
Share of other comprehensive loss of joint ventures and associates	(1,446,000,000)		(1,251,000,000)
Loss on foreign currencies translation of foreign operations	(206,037,000,000)		(242,700,000,000)
Remeasurement loss related to defined benefit plan	(211,838,000,000)		(152,624,000,000)
Gain(loss) on valuation of cash flow hedges	(5,436,000,000)		777,000,000
Equity related to non-current assets held for sale	(564,000,000)		4,145,000,000
Sub-total	(472,038,000,000)		(89,723,000,000)	₩ 70,750,000,000	₩ 173,368,000,000
Treasury shares	(34,113,000,000)		(34,113,000,000)
Other capital adjustments	(1,607,647,000,000)		(1,815,438,000,000)
Total	₩ (2,113,798,000,000)	$ (1,901,239)	₩ (1,939,274,000,000)

Other equity_Changes in the acc

Other equity_Changes in the accumulated other comprehensive loss (Details) - KRW (₩)		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
Disclosure of analysis of other comprehensive income by item [Line Items]
Beginning balance	[1]	₩ (481,900,000,000)
Beginning balance		(89,723,000,000)	₩ 173,368,000,000
Changes in accumulated other comprehensive income [Abstract]
Increase (decrease) on valuation		20,229,000,000	(47,643,000,000)
Reclassification		(4,839,000,000)	(81,114,000,000)
Income tax effect		(5,528,000,000)	26,139,000,000
Ending balance		₩ (472,038,000,000)	70,750,000,000
Explanation of transfers of cumulative gain or loss within equity of investments in equity designated as measured at fair value through other comprehensive income		Net gain or loss on valuation of financial assets at FVTOCI included the 1,500 million Won transfer to retained earnings due to disposal of equity securities.
Gain (loss) on valuation of available-for-sale financial assets
Disclosure of analysis of other comprehensive income by item [Line Items]
Beginning balance			386,981,000,000
Changes in accumulated other comprehensive income [Abstract]
Increase (decrease) on valuation	[2]		46,479,000,000
Reclassification	[2]		(81,114,000,000)
Income tax effect			5,602,000,000
Ending balance			357,948,000,000
Net gain or loss on valuation of financial assets at FVTOCI
Disclosure of analysis of other comprehensive income by item [Line Items]
Beginning balance	[1]	₩ (88,906,000,000)
Changes in accumulated other comprehensive income [Abstract]
Increase (decrease) on valuation	[3]	58,846,000,000
Reclassification		(694,000,000)
Income tax effect		(15,992,000,000)
Ending balance		(46,746,000,000)
Gain (loss) on financial liabilities at fair value through profit or loss designated as upon initial recognition due to own credit risk
Disclosure of analysis of other comprehensive income by item [Line Items]
Beginning balance	[1]	(96,000,000)
Changes in accumulated other comprehensive income [Abstract]
Increase (decrease) on valuation		172,000,000
Reclassification		0
Income tax effect		(47,000,000)
Ending balance		29,000,000
Share of other comprehensive income (loss) of joint ventures and associates
Disclosure of analysis of other comprehensive income by item [Line Items]
Beginning balance	[1]	(2,656,000,000)
Beginning balance			(1,863,000,000)
Changes in accumulated other comprehensive income [Abstract]
Increase (decrease) on valuation		1,669,000,000	2,038,000,000
Reclassification		0	0
Income tax effect		(459,000,000)	(531,000,000)
Ending balance		(1,446,000,000)	(356,000,000)
Gain (loss) on foreign currency translation of foreign operations
Disclosure of analysis of other comprehensive income by item [Line Items]
Beginning balance	[1]	(242,806,000,000)
Beginning balance			(48,353,000,000)
Changes in accumulated other comprehensive income [Abstract]
Increase (decrease) on valuation		50,717,000,000	(81,571,000,000)
Reclassification		0	0
Income tax effect		(13,948,000,000)	17,627,000,000
Ending balance		(206,037,000,000)	(112,297,000,000)
Remeasurement gain (loss) related to defined benefit plan
Disclosure of analysis of other comprehensive income by item [Line Items]
Beginning balance	[1]	(152,358,000,000)
Beginning balance			(163,397,000,000)
Changes in accumulated other comprehensive income [Abstract]
Increase (decrease) on valuation		(82,041,000,000)	(12,642,000,000)
Reclassification		0	0
Income tax effect		22,561,000,000	3,020,000,000
Ending balance		(211,838,000,000)	(173,019,000,000)
Gain (loss) on valuation of cash flow hedges
Disclosure of analysis of other comprehensive income by item [Line Items]
Beginning balance	[1]	777,000,000
Changes in accumulated other comprehensive income [Abstract]
Increase (decrease) on valuation		(8,570,000,000)	(1,947,000,000)
Reclassification		0	0
Income tax effect		2,357,000,000	421,000,000
Ending balance		(5,436,000,000)	(1,526,000,000)
Transfer to non-current assets held for sale
Disclosure of analysis of other comprehensive income by item [Line Items]
Beginning balance	[1]	4,145,000,000
Beginning balance			₩ 0
Changes in accumulated other comprehensive income [Abstract]
Increase (decrease) on valuation		(564,000,000)
Reclassification		(4,145,000,000)
Income tax effect		0
Ending balance		₩ (564,000,000)
[1]	The beginning balance was restated in accordance with IFRS 9.
[2]	For the change in gain (loss) on valuation of AFS financial assets, “increase (decrease)” represents change due to the valuation during the period, and “reclassification adjustments” represents disposal or recognition of impairment losses on AFS financial assets.
[3]	Net gain or loss on valuation of financial assets at FVTOCI included the 1,500 million Won transfer to retained earnings due to disposal of equity securities.

Retained earnings_Details of re

Retained earnings_Details of retained earnings (Details) $ in Thousands		3 Months Ended		6 Months Ended			12 Months Ended
		Jun. 30, 2018KRW (₩)	Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)	Dec. 31, 2017KRW (₩)
Disclosure of changes in retained earnings [Line Items]
Beginning balance	[1]			₩ 15,797,097,000,000
Beginning balance				15,620,006,000,000		₩ 14,611,566,000,000	₩ 14,611,566,000,000
Changes in retained earnings [Abstract]
Net income attributable to owners		₩ 716,142,000,000	₩ 460,888,000,000	1,305,878,000,000	$ 1,174,562	1,098,361,000,000
Dividends on common stock				(336,636,000,000)		(269,308,000,000)	(336,636,000,000)
Dividends on hybrid securities				(75,603,000,000)		(90,823,000,000)
Loss on disposal of equity securities at FVTOCI		(424,000,000)		(424,000,000)			0
Derecognition of the credit risk on financial liabilities designated at FVTPL				5,000,000			0
Capital adjustments due to appropriation of retained earnings				(216,864,000,000)			0
Ending balance		16,473,453,000,000	₩ 15,349,796,000,000	16,473,453,000,000	$ 14,816,921	₩ 15,349,796,000,000	15,620,006,000,000
Legal Reserve Sub-total		1,904,138,000,000		1,904,138,000,000			1,775,422,000,000
Voluntary reserve Sub-total		11,297,521,000,000		11,297,521,000,000			10,864,061,000,000
Conversion of loss on disposal of equity securities at FVTOCI to retained earnings		(424,000,000)		(424,000,000)
Derecognition of the credit risk on financial liabilities designated at FVTPL		5,000,000		5,000,000
Retained earnings before appropriation		3,272,213,000,000		3,272,213,000,000			2,980,523,000,000
Earned surplus reserve
Changes in retained earnings [Abstract]
Legal Reserve Sub-total		1,857,754,000,000		₩ 1,857,754,000,000			₩ 1,729,754,000,000
Description of nature and purpose of legal reserves within equity				In accordance with the Banking Act, earned surplus reserve is appropriated at least one tenth of the earnings after tax on every dividend declaration, not exceeding the paid in capital. This reserve may not be used other than for offsetting a deficit or transferring to capital.	In accordance with the Banking Act, earned surplus reserve is appropriated at least one tenth of the earnings after tax on every dividend declaration, not exceeding the paid in capital. This reserve may not be used other than for offsetting a deficit or transferring to capital.		In accordance with the Banking Act, earned surplus reserve is appropriated at least one tenth of the earnings after tax on every dividend declaration, not exceeding the paid in capital. This reserve may not be used other than for offsetting a deficit or transferring to capital.
Other legal reserve
Changes in retained earnings [Abstract]
Legal Reserve Sub-total		46,384,000,000		₩ 46,384,000,000			₩ 45,668,000,000
Description of nature and purpose of legal reserves within equity				Other legal reserves were appropriated in the branches located in Japan, Vietnam and Bangladesh according to the banking laws of Japan, Vietnam and Bangladesh, and may be used to offset any deficit incurred in those branches.	Other legal reserves were appropriated in the branches located in Japan, Vietnam and Bangladesh according to the banking laws of Japan, Vietnam and Bangladesh, and may be used to offset any deficit incurred in those branches.		Other legal reserves were appropriated in the branches located in Japan, Vietnam and Bangladesh according to the banking laws of Japan, Vietnam and Bangladesh, and may be used to offset any deficit incurred in those branches.
Business rationalization reserve
Changes in retained earnings [Abstract]
Voluntary reserve Sub-total		8,000,000,000		₩ 8,000,000,000			₩ 8,000,000,000
Description of nature and purpose of voluntary reserves within equity				Pursuant to the Restriction of Special Taxation Act, the Group was previously required to appropriate, as a reserve for business rationalization, amounts equal to tax reductions arising from tax exemptions and tax credits up to December 31, 2001. The requirement was no longer effective from 2002.	Pursuant to the Restriction of Special Taxation Act, the Group was previously required to appropriate, as a reserve for business rationalization, amounts equal to tax reductions arising from tax exemptions and tax credits up to December 31, 2001. The requirement was no longer effective from 2002.		Pursuant to the Restriction of Special Taxation Act, the Group was previously required to appropriate, as a reserve for business rationalization, amounts equal to tax reductions arising from tax exemptions and tax credits up to December 31, 2001. The requirement was no longer effective from 2002.
Reserve for financial structure improvement
Changes in retained earnings [Abstract]
Voluntary reserve Sub-total		235,400,000,000		₩ 235,400,000,000			₩ 235,400,000,000
Description of nature and purpose of voluntary reserves within equity				From 2002 to 2014, the Finance Supervisory Services recommended banks in Korea to appropriate at least 10 percent of net income after accumulated deficit for financial structure improvement, until tangible common equity ratio equals 5.5 percent. But this reserve is not available for payment of cash dividends; however, it can be used to reduce a deficit or be transferred to capital. The reserve and appropriation are an Autonomous judgment matter of the Group since 2015.	From 2002 to 2014, the Finance Supervisory Services recommended banks in Korea to appropriate at least 10 percent of net income after accumulated deficit for financial structure improvement, until tangible common equity ratio equals 5.5 percent. But this reserve is not available for payment of cash dividends; however, it can be used to reduce a deficit or be transferred to capital. The reserve and appropriation are an Autonomous judgment matter of the Group since 2015.		From 2002 to 2014, the Finance Supervisory Services recommended banks in Korea to appropriate at least 10 percent of net income after accumulated deficit for financial structure improvement, until tangible common equity ratio equals 5.5 percent. But this reserve is not available for payment of cash dividends; however, it can be used to reduce a deficit or be transferred to capital. The reserve and appropriation are an Autonomous judgment matter of the Group since 2015.
Additional reserve
Changes in retained earnings [Abstract]
Voluntary reserve Sub-total		7,759,804,000,000		₩ 7,759,804,000,000			₩ 7,418,806,000,000
Description of nature and purpose of voluntary reserves within equity				Additional reserve was appropriated for capital adequacy and other management purpose.	Additional reserve was appropriated for capital adequacy and other management purpose.		Additional reserve was appropriated for capital adequacy and other management purpose.
Regulatory reserve for credit loss
Changes in retained earnings [Abstract]
Voluntary reserve Sub-total		2,578,457,000,000		₩ 2,578,457,000,000			₩ 2,438,191,000,000
Description of nature and purpose of voluntary reserves within equity				In accordance with Article 29 of the Regulation on Supervision of Banking Business (“RSBB”), if provisions for credit loss under IFRS for the accounting purpose are lower than provisions under RSBB, the Group discloses such short fall amount as regulatory reserve for credit loss.	In accordance with Article 29 of the Regulation on Supervision of Banking Business (“RSBB”), if provisions for credit loss under IFRS for the accounting purpose are lower than provisions under RSBB, the Group discloses such short fall amount as regulatory reserve for credit loss.		In accordance with Article 29 of the Regulation on Supervision of Banking Business (“RSBB”), if provisions for credit loss under IFRS for the accounting purpose are lower than provisions under RSBB, the Group discloses such short fall amount as regulatory reserve for credit loss.
Revaluation reserve
Changes in retained earnings [Abstract]
Voluntary reserve Sub-total		715,860,000,000		₩ 715,860,000,000			₩ 751,964,000,000
Description of nature and purpose of voluntary reserves within equity				Revaluation reserve is the amount of limited dividends set by the board of directors to be the recognized as complementary capital when the gain or loss occurred in the property revaluation by adopting IFRS.	Revaluation reserve is the amount of limited dividends set by the board of directors to be the recognized as complementary capital when the gain or loss occurred in the property revaluation by adopting IFRS.		Revaluation reserve is the amount of limited dividends set by the board of directors to be the recognized as complementary capital when the gain or loss occurred in the property revaluation by adopting IFRS.
Other voluntary reserve
Changes in retained earnings [Abstract]
Voluntary reserve Sub-total		₩ 0		₩ 0			₩ 11,700,000,000
[1]	The beginning balance was restated in accordance with IFRS 9.

Dividends_Details of dividend a

Dividends_Details of dividend approved and paid (Details) ₩ / shares in Units, ₩ in Millions	6 Months Ended
	Jun. 30, 2018KRW (₩)₩ / shares	[1]
Dividends [Abstract]
Dividend paid | ₩	₩ 336,636
Dividend paid per share | ₩ / shares	₩ 500
[1]	At the shareholders’ meeting on March 23, 2018, dividend payment for the year ended December 31, 2017 amounting to 336,636 million Won (500 Won per share) was approved and paid for the six months ended June 30, 2018

Net interest income_Details of

Net interest income_Details of interest income (Details)	3 Months Ended			6 Months Ended
	Jun. 30, 2018KRW (₩)		Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)		Jun. 30, 2017KRW (₩)
Disclosure of interest income operating [Abstract]
Financial assets at FVTPL (IFRS 9)	₩ 13,367,000,000	[1]	₩ 0	₩ 28,537,000,000	[1]	$ 25,667,000	[1]	₩ 0
Financial assets at FVTPL (IAS 39)	0		13,074,000,000	0		0		26,806,000,000
Financial assets at FVTOCI	62,170,000,000	[1]	0	119,446,000,000	[1]	107,435,000	[1]	0
AFS financial assets	0		67,667,000,000	0		0		144,067,000,000
Securities at amortized cost	87,587,000,000		0	168,789,000,000				0
HTM financial assets	0		74,690,000,000	0		0		149,673,000,000
Financial assets at amortized cost:
Interest on due from banks	28,323,000,000		0	61,461,000,000				0
Interest on loans	2,170,291,000,000		0	4,251,497,000,000				0
Interest of other receivables	6,931,000,000		0	13,686,000,000				0
Sub-total	2,205,545,000,000		0	4,326,644,000,000				0
Loans and receivables
Interest on due from banks	0		20,182,000,000	0				41,403,000,000
Interest on loans	0		1,921,359,000,000	0				3,810,008,000,000
Interest of other receivables	0		8,836,000,000	0				17,627,000,000
Sub-total	0		1,950,377,000,000	0		0		3,869,038,000,000
Total	₩ 2,368,669,000,000		₩ 2,105,808,000,000	₩ 4,643,416,000,000		$ 4,176,485,000		₩ 4,189,584,000,000
[1]	The consolidated interim statements of comprehensive income for the three months and six months ended June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated interim statements of comprehensive income for the three months and six months ended June 30, 2017 was not retrospectively restated in accordance with IFRS 9.

Net interest income_Details 218

Net interest income_Details of interest expense (Details) $ in Thousands, ₩ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018KRW (₩)	Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Interest expense [Abstract]
Interest on deposits due to customers	₩ 704,007	₩ 586,051	₩ 1,358,964		₩ 1,174,384
Interest on borrowings	70,519	57,666	129,929		115,548
Interest on debentures	174,890	154,445	346,948		305,804
Interest expense on others	21,930	20,070	43,101		43,528
Total	₩ 971,346	₩ 818,232	₩ 1,878,942	$ 1,690,000	₩ 1,639,264

Net fees and commissions inc219

Net fees and commissions income_Details of fees and commissions income recognized (Details) $ in Thousands, ₩ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2018KRW (₩)	Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Fee and commission income [Abstract]
Fees and commissions received	[1]	₩ 169,171	₩ 163,688	₩ 346,925		₩ 336,322
Fees and commissions received for provision of guarantee		14,660	15,911	30,263		31,700
Fees and commissions received on project financing		10,528	4,614	16,945		6,334
Fees and commissions received on credit card		283,407	268,887	556,984		527,566
Fees and commissions received on securities		23,767	19,757	50,238		40,267
Other fees and commissions received		53,867	33,424	111,651		71,704
Total		₩ 555,400	₩ 506,281	₩ 1,113,006	$ 1,001,084	₩ 1,013,893
Disclosure of composition of banking fees explanatory	[1]	Fees and commissions received include fees income from agency commission, fees income from electronic finance, fees income related to loan, fees for import letter of credit dealing, commission received on foreign exchange and others.	Fees and commissions received include fees income from agency commission, fees income from electronic finance, fees income related to loan, fees for import letter of credit dealing, commission received on foreign exchange and others.	Fees and commissions received include fees income from agency commission, fees income from electronic finance, fees income related to loan, fees for import letter of credit dealing, commission received on foreign exchange and others.	Fees and commissions received include fees income from agency commission, fees income from electronic finance, fees income related to loan, fees for import letter of credit dealing, commission received on foreign exchange and others.	Fees and commissions received include fees income from agency commission, fees income from electronic finance, fees income related to loan, fees for import letter of credit dealing, commission received on foreign exchange and others.
[1]	Fees and commissions received include fees income from agency commission, fees income from electronic finance, fees income related to loan, fees for import letter of credit dealing, commission received on foreign exchange and others.

Net fees and commissions inc220

Net fees and commissions income_Details of fees and commissions expense incurred (Details) $ in Thousands, ₩ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018KRW (₩)	Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Fee and commission expense [Abstract]
Fees and commissions paid	₩ 41,532	₩ 41,930	₩ 80,866		₩ 73,167
Credit card commissions	213,887	200,275	425,204		400,349
Brokerage commissions	934	121	1,268		348
Others	1,700	1,207	3,013		2,329
Total	₩ 258,053	₩ 243,533	₩ 510,351	$ 459,031	₩ 476,193

Dividend income_Details of divi

Dividend income_Details of dividend income (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018KRW (₩)	Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Disclosure Of Revenue From Dividends [Abstract]
Dividend from financial assets at FVTPL (IFRS 9)	₩ 12,210,000,000	₩ 0	₩ 31,860,000,000		₩ 0
Dividend from financial assets at FVTPL (IAS 39)	0	47,000,000	0		190,000,000
Dividend from financial assets FVTOCI	1,941,000,000	0	17,844,000,000		0
Dividend from AFS financial assets	0	19,570,000,000	0		59,255,000,000
Total	₩ 14,151,000,000	₩ 19,617,000,000	₩ 49,704,000,000	$ 44,706	₩ 59,445,000,000

Dividend income_Details of d222

Dividend income_Details of dividends related to financial assets at FVTOCI (Details) ₩ in Millions	6 Months Ended
	Jun. 30, 2018KRW (₩)
Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [Abstract]
Dividend income recognized from assets held equity securities	₩ 17,570
Dividend income recognized in assets derecognized	274
Total	₩ 17,844

Net gain or loss on financia223

Net gain or loss on financial instruments at fair value through profit or loss mandatorily measured at fair value (IFRS 9 And IAS 39)_Details of gains or losses related to net gain or loss on financial instruments at FVTPL (Details)	3 Months Ended			6 Months Ended
	Jun. 30, 2018KRW (₩)		Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)		Jun. 30, 2017KRW (₩)
Disclosure of gains (losses) on financial instruments at fair value through profit or loss [Abstract]
Gains (losses) on financial assets at fair value through profit or loss mandatorily measured at fair value	₩ 70,116,000,000		₩ 0	₩ 114,146,000,000				₩ 0
Gains (losses) on financial assets held for trading	0		36,266,000,000	0				(60,186,000,000)
Gains (losses) on financial instrument at fair value through profit or loss designated as upon initial recognition (IFRS 9)	(2,423,000,000)		0	2,877,000,000				0
Gains (losses) on financial instruments at fair value through profit or loss designated as upon initial recognition (IAS39)	0		(24,200,000,000)	0				(86,223,000,000)
Total	67,693,000,000	[1]	0	117,023,000,000	[1]	$ 105,255,000	[1]	0
Total	₩ 0		₩ 12,066,000,000	₩ 0		$ 0		₩ (146,409,000,000)
[1]	The consolidated interim statements of comprehensive income for the three months and six months ended June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated interim statements of comprehensive income for the three months and six months ended June 30, 2017 was not retrospectively restated in accordance with IFRS 9.

Net gain or loss on financia224

Net gain or loss on financial instruments at fair value through profit or loss mandatorily measured at fair value (IFRS 9 And IAS 39)_Details of net gain or loss on financial instrument at fair value through profit or loss mandatorily measured at fair value and financial assets held for trading (Details) - KRW (₩)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	₩ 70,116,000,000	₩ 0	₩ 114,146,000,000	₩ 0
Net gains and losses on financial assets held for trading (Total)	0	36,266,000,000	0	(60,186,000,000)
Financial assets at FVTPL (financial assets held for trading)
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	36,735,000,000		74,425,000,000
Net gains and losses on financial assets held for trading (Total)		1,025,000,000		7,367,000,000
Securities
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	36,429,000,000		71,263,000,000
Net gains and losses on financial assets held for trading (Total)		898,000,000		7,187,000,000
Securities | Gain on valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	36,982,000,000		81,861,000,000
Net gains and losses on financial assets held for trading (Total)		1,055,000,000		5,895,000,000
Securities | Gain on disposals
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	18,885,000,000		22,377,000,000
Net gains and losses on financial assets held for trading (Total)		3,936,000,000		9,860,000,000
Securities | Loss on valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	(11,957,000,000)		(23,795,000,000)
Net gains and losses on financial assets held for trading (Total)		(2,785,000,000)		(6,511,000,000)
Securities | Loss on disposals
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	(7,481,000,000)		(9,180,000,000)
Net gains and losses on financial assets held for trading (Total)		(1,308,000,000)		(2,057,000,000)
Loans
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	266,000,000		3,064,000,000
Net gains and losses on financial assets held for trading (Total)		0		0
Loans | Gain on valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	373,000,000		3,191,000,000
Net gains and losses on financial assets held for trading (Total)		0		0
Loans | Loss on valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	(107,000,000)		(127,000,000)
Net gains and losses on financial assets held for trading (Total)		0		0
Other financial assets
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	40,000,000		98,000,000
Net gains and losses on financial assets held for trading (Total)		127,000,000		180,000,000
Other financial assets | Gain on valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	228,000,000		1,969,000,000
Net gains and losses on financial assets held for trading (Total)		1,495,000,000		3,071,000,000
Other financial assets | Gain on disposals
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	143,000,000		405,000,000
Net gains and losses on financial assets held for trading (Total)		814,000,000		933,000,000
Other financial assets | Loss on valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	(320,000,000)		(2,193,000,000)
Net gains and losses on financial assets held for trading (Total)		(1,971,000,000)		(3,590,000,000)
Other financial assets | Loss on disposals
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	(11,000,000)		(83,000,000)
Net gains and losses on financial assets held for trading (Total)		(211,000,000)		(234,000,000)
Derivatives (for trading)
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	33,381,000,000		39,721,000,000
Net gains and losses on financial assets held for trading (Total)		35,241,000,000		(67,553,000,000)
Interest rates derivatives
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	(16,009,000,000)		5,837,000,000
Net gains and losses on financial assets held for trading (Total)		3,467,000,000		11,615,000,000
Interest rates derivatives | Gain on transactions and valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	231,372,000,000		600,362,000,000
Net gains and losses on financial assets held for trading (Total)		201,637,000,000		433,349,000,000
Interest rates derivatives | Loss on transactions and valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	(247,381,000,000)		(594,525,000,000)
Net gains and losses on financial assets held for trading (Total)		(198,170,000,000)		(421,734,000,000)
Currencies derivatives
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	43,220,000,000		29,216,000,000
Net gains and losses on financial assets held for trading (Total)		10,849,000,000		(170,044,000,000)
Currencies derivatives | Gain on transactions and valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	2,546,154,000,000		3,535,106,000,000
Net gains and losses on financial assets held for trading (Total)		(94,206,000,000)		3,773,565,000,000
Currencies derivatives | Loss on transactions and valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	(2,502,934,000,000)		(3,505,890,000,000)
Net gains and losses on financial assets held for trading (Total)		105,055,000,000		(3,943,609,000,000)
Equity derivatives
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	6,424,000,000		5,301,000,000
Net gains and losses on financial assets held for trading (Total)		21,186,000,000		91,376,000,000
Equity derivatives | Gain on transactions and valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	115,712,000,000		249,364,000,000
Net gains and losses on financial assets held for trading (Total)		92,302,000,000		302,927,000,000
Equity derivatives | Loss on transactions and valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	(109,288,000,000)		(244,063,000,000)
Net gains and losses on financial assets held for trading (Total)		(71,116,000,000)		(211,551,000,000)
Other derivatives
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	(254,000,000)		(633,000,000)
Net gains and losses on financial assets held for trading (Total)		(261,000,000)		(500,000,000)
Other derivatives | Gain on transactions and valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	2,142,000,000		2,790,000,000
Net gains and losses on financial assets held for trading (Total)		2,295,000,000		12,312,000,000
Other derivatives | Loss on transactions and valuation
Gains losses on financial instruments held for trading [Line Items]
Net gains and losses on financial instruments at FVTPL classified as held for trading (Total)	₩ (2,396,000,000)		₩ (3,423,000,000)
Net gains and losses on financial assets held for trading (Total)		₩ (2,556,000,000)		₩ (12,812,000,000)

Net gain or loss on financia225

Net gain or loss on financial instruments at fair value through profit or loss mandatorily measured at fair value (IFRS 9 And IAS 39)_Details of net gain or loss on financial instrument at fair value through profit or loss designated as upon initial recognition (Details) - KRW (₩)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Gains losses on financial instruments at fair value through profit or loss designated as upon initial recognition [Line Items]
Gains (losses) on financial instrument at fair value through profit or loss designated as upon initial recognition (IFRS 9)	₩ (2,423,000,000)	₩ 0	₩ 2,877,000,000	₩ 0
Gains (losses) on financial instruments at fair value through profit or loss designated as upon initial recognition (IAS39)	0	(24,200,000,000)	0	(86,223,000,000)
Equity-linked securities
Gains losses on financial instruments at fair value through profit or loss designated as upon initial recognition [Line Items]
Gains (losses) on financial instrument at fair value through profit or loss designated as upon initial recognition (IFRS 9)	(3,367,000,000)		1,280,000,000
Gains (losses) on financial instruments at fair value through profit or loss designated as upon initial recognition (IAS39)		(24,353,000,000)		(85,591,000,000)
Net gains and losses on disposals | Equity-linked securities
Gains losses on financial instruments at fair value through profit or loss designated as upon initial recognition [Line Items]
Gains (losses) on financial instrument at fair value through profit or loss designated as upon initial recognition (IFRS 9)	(1,203,000,000)		(1,534,000,000)
Gains (losses) on financial instruments at fair value through profit or loss designated as upon initial recognition (IAS39)		(3,686,000,000)		(15,877,000,000)
Net gains and losses on valuation | Equity-linked securities
Gains losses on financial instruments at fair value through profit or loss designated as upon initial recognition [Line Items]
Gains (losses) on financial instrument at fair value through profit or loss designated as upon initial recognition (IFRS 9)	(2,164,000,000)		2,814,000,000
Gains (losses) on financial instruments at fair value through profit or loss designated as upon initial recognition (IAS39)		(20,667,000,000)		(69,714,000,000)
Net gains and losses on valuation | Securities
Gains losses on financial instruments at fair value through profit or loss designated as upon initial recognition [Line Items]
Gains (losses) on financial instrument at fair value through profit or loss designated as upon initial recognition (IFRS 9)	0		0
Gains (losses) on financial instruments at fair value through profit or loss designated as upon initial recognition (IAS39)		(114,000,000)		(16,000,000)
Net gains and losses on valuation | Other financial instruments
Gains losses on financial instruments at fair value through profit or loss designated as upon initial recognition [Line Items]
Gains (losses) on financial instrument at fair value through profit or loss designated as upon initial recognition (IFRS 9)	₩ 944,000,000		₩ 1,597,000,000
Gains (losses) on financial instruments at fair value through profit or loss designated as upon initial recognition (IAS39)		₩ 267,000,000		₩ (616,000,000)

Net gain or loss on financial a

Net gain or loss on financial assets at FVTOCI and AFS financial assets_Details of net gain on financial assets at FVTOCI and AFS financial assets recognized (Details)	3 Months Ended			6 Months Ended
	Jun. 30, 2018KRW (₩)		Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)		Jun. 30, 2018USD ($)		Jun. 30, 2017KRW (₩)
Disclosure of gains losses recognised in profit or loss availableforsale financial assets [Abstract]
Gains on redemption of securities (IFRS 9)	₩ 11,000,000			₩ 16,000,000
Gains on redemption of securities (IAS 39)			₩ 220,000,000					₩ 547,000,000
Gains on transaction of securities (IFRS 9)	464,000,000			1,271,000,000
Gains on transaction of securities (IAS 39)			95,019,000,000					116,262,000,000
Impairment losses on securities (IFRS 9)	0			0
Impairment losses on securities (IAS 39)			(6,852,000,000)					(12,637,000,000)
Total	475,000,000	[1]	0	1,287,000,000	[1]	$ 1,158,000	[1]	0
Total	₩ 0		₩ 88,387,000,000	₩ 0		$ 0		₩ 104,172,000,000
[1]	The consolidated interim statements of comprehensive income for the three months and six months ended June 30, 2018 was prepared in accordance with IFRS 9; however, the comparative consolidated interim statements of comprehensive income for the three months and six months ended June 30, 2017 was not retrospectively restated in accordance with IFRS 9.

Impairment reverse (losses) due

Impairment reverse (losses) due to credit loss_Impairment reverse Losses due to credit loss (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018KRW (₩)	Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Disclosure of impairment losses due to credit loss [Abstract]
Reversal of credit loss on financial assets at financial assets at FVTOCI	₩ (679,000,000)	₩ 0	₩ (459,000,000)		₩ 0
Reversal of credit loss on securities at amortized cost losses	(199,000,000)	0	(191,000,000)		0
Provision for credit loss on loans and other financial assets at amortized cost	76,699,000,000	0	(61,057,000,000)		0
Impairment losses due to credit loss	0	(211,842,000,000)	0		(333,976,000,000)
Reversal of provision on (provision for) guarantees	76,354,000,000	16,071,000,000	86,990,000,000		44,968,000,000
Reversal of provision on (provision for) loan commitment	(1,502,000,000)	(8,715,000,000)	3,155,000,000		5,245,000,000
Total	₩ 150,673,000,000	₩ (204,486,000,000)	₩ 28,438,000,000	$ 25,578	₩ (283,763,000,000)

General administrative expen228

General administrative expenses and other net operating incomes (expenses)_Details of administrative expenses (Details) $ in Thousands, ₩ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018KRW (₩)	Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Employee benefits
Salaries	₩ 341,645	₩ 326,034	₩ 644,663		₩ 654,191
Employee benefits	108,933	114,170	213,627		213,600
Retirement benefit service costs	36,610	36,972	72,936		74,057
Termination	20,994	5,477	20,994		5,477
Sub total	508,182	482,653	952,220		947,325
Depreciation and amortisation expense [Abstract]
Depreciation and amortization	52,222	45,380	99,698		94,927
Other general and administrative expense [Abstract]
Rent	79,546	76,297	159,126		156,708
Taxes and public dues	38,275	34,077	67,385		63,178
Service charges	52,807	47,611	104,970		96,418
Computer and IT related	21,704	16,089	43,581		30,477
Telephone and communication	16,819	16,111	33,729		31,590
Operating promotion	9,339	10,003	19,768		21,053
Advertising	13,808	22,434	20,493		29,880
Printing	1,928	2,095	3,892		4,237
Traveling	2,679	2,920	6,034		6,024
Supplies	1,737	1,517	3,223		3,117
Insurance premium	1,961	1,956	4,002		4,169
Reimbursement	4,964	4,710	5,902		9,177
Maintenance	3,672	3,331	8,027		6,882
Water, light and heating	2,809	2,883	7,203		7,146
Vehicle maintenance	2,379	2,602	4,594		4,964
Others	12,823	11,488	23,491		21,155
Sub total	267,250	256,124	515,420		496,175
Total	₩ 827,654	₩ 784,157	₩ 1,567,338	$ 1,409,730	₩ 1,538,427

General administrative expen229

General administrative expenses and other net operating incomes (expenses)_Details of other operating incomes (Details) - KRW (₩)		3 Months Ended			6 Months Ended
		Jun. 30, 2018		Jun. 30, 2017	Jun. 30, 2018		Jun. 30, 2017
Other operating income [Abstract]
Gains on transaction of foreign exchange		₩ 157,245,000,000		₩ 619,297,000,000	₩ 847,397,000,000		₩ 1,698,987,000,000
Gains on disposal of loans and receivables		0	[1]	14,861,000,000	0	[1]	201,860,000,000
Gains on transactions of derivatives		26,373,000,000		11,592,000,000	28,943,000,000		11,656,000,000
Gains on fair value hedged items		18,861,000,000		(7,094,000,000)	66,555,000,000		11,860,000,000
Others		1,741,000,000		5,813,000,000	17,522,000,000		68,668,000,000	[2]
Total		₩ 204,220,000,000		₩ 644,469,000,000	₩ 960,417,000,000		1,993,031,000,000
Income for payment to other creditor financial institutions	[2]						₩ 28,800,000,000
[1]	Gain on disposal of loan and receivables occurred for the six month ended June 30, 2018 was presented into a separate account for gain related to financial assets at amortized cost in accordance with the adoption of IFRS 9.
[2]	Other income includes such income amounting to 28,800 million Won for the six months ended June 30, 2017, respectively, that the Group recognized for it is to receive from other creditor financial institutions in accordance with the creditor financial institutions committee agreement.

General administrative expen230

General administrative expenses and other net operating incomes (expenses)_Details of other operating expenses (Details) - KRW (₩)		3 Months Ended			6 Months Ended
		Jun. 30, 2018		Jun. 30, 2017	Jun. 30, 2018		Jun. 30, 2017
Other operating expenses [Abstract]
Losses on transaction of foreign exchange		₩ 114,971,000,000		₩ 534,740,000,000	₩ 726,348,000,000		₩ 1,374,764,000,000
KDIC deposit insurance premium		79,585,000,000		77,146,000,000	156,765,000,000		150,256,000,000
Contribution to miscellaneous funds		73,849,000,000		71,927,000,000	146,781,000,000		144,262,000,000
Losses(gains) on disposals of loans and receivables		0	[1]	(40,000,000)	0	[1]	28,000,000
Losses(gains) related to derivatives		13,059,000,000		(16,441,000,000)	62,366,000,000		31,131,000,000
Losses(gains) on fair value hedged items		0		15,820,000,000	0		15,846,000,000
Others	[2]	45,707,000,000		38,584,000,000	87,571,000,000		75,554,000,000
Total		327,171,000,000		721,736,000,000	1,179,831,000,000		1,791,841,000,000
Expenses for payment to other creditor financial institutions	[2]	₩ 25,179,000,000		₩ 24,443,000,000	1,412,000,000		3,325,000,000
Amortisation of other intangible assets included in other operating expenses					₩ 25,179,000,000	[3]	₩ 24,443,000,000	[4]
[1]	Loss on disposal of loan and receivables occurred for the six month ended June 30, 2018 was presented into a separate account for loss related to financial assets at amortized cost in accordance with the adoption of IFRS 9
[2]	Other expense includes such expenses amounting to 1,412 million Won and 3,325 million Won for the six months ended June 30, 2018 and 2017, respectively, which are related to the Group’s expected payments to other creditor financial institutions in accordance with the creditor financial institutions committee agreement. In addition, ‘Other expense’ for the six months ended June 30, 2018 and 2017 includes 25,179 million Won and 24,443 million Won, respectively, of intangible asset amortization expense.
[3]	Amortization of other intangible assets amounting to 25,179 million Won is included in other operating expenses.
[4]	Amortization of other intangible assets amounting to 24,443 million Won is included in other operating expenses.

Other non-operating income (231

Other non-operating income (expense)_Details of non operating incomes and expenses (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018KRW (₩)	Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Gain or loss on valuation of investments in associates and joint ventures
Gain on valuation	₩ 10,687,000,000	₩ (10,061,000,000)	₩ 15,347,000,000		₩ 3,316,000,000
Loss on valuation	(3,006,000,000)	521,000,000	(16,809,000,000)		(62,271,000,000)
Impairment loss	0	(5,323,000,000)	0		(5,323,000,000)
Total	7,681,000,000	(14,863,000,000)	(1,462,000,000)	$ (1,315)	(64,278,000,000)
Other income disclosure nonoperating [Abstract]
Rental fee income	1,687,000,000	1,880,000,000	3,203,000,000		3,700,000,000
Gains on disposal of investment in joint ventures and associates	0	4,466,000,000	0		32,886,000,000
Gains on disposal of premises and equipment, intangble assets and other assets	15,760,000,000	1,494,000,000	17,037,000,000		1,675,000,000
Reversal of impairment loss of premises and equipment, intangible assets and other assets	1,000,000	0	341,000,000		32,000,000
Others	5,897,000,000	22,571,000,000	18,460,000,000		38,892,000,000
Total	23,345,000,000	30,411,000,000	39,041,000,000		77,185,000,000
Other expense disclosure nonoperating [Abstract]
Depreciation on investment properties	1,004,000,000	992,000,000	2,010,000,000		1,991,000,000
Interest expenses of rent leasehold deposits	150,000,000	105,000,000	292,000,000		223,000,000
Losses on disposal of investment in joint ventures and associates	0	46,000,000	2,931,000,000		27,730,000,000
Losses on disposal of premises and equipment and other assets	167,000,000	271,000,000	221,000,000		608,000,000
Impairment losses on premises and equipment and other assets	2,000,000	40,000,000	2,000,000		160,000,000
Donation	8,551,000,000	10,426,000,000	22,042,000,000		14,980,000,000
Others	12,073,000,000	6,834,000,000	16,264,000,000		21,495,000,000
Total	21,947,000,000	18,714,000,000	43,762,000,000		67,187,000,000
Total	₩ 1,398,000,000	₩ 11,697,000,000	₩ (4,721,000,000)	$ (4,246)	₩ 9,998,000,000

Income tax expense_Details of i

Income tax expense_Details of income tax expenses (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018KRW (₩)	Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Current tax expense
Current tax expense in respect of the current year			₩ 231,393,000,000		₩ 284,030,000,000
Adjustments recognized in the current period in relation to the current tax of prior periods			(3,632,000,000)		(4,919,000,000)
Sub total			227,761,000,000		279,111,000,000
Deferred tax expense
Deferred tax assets(liabilities) relating to the origination and reversal of temporary differences			182,515,000,000		13,889,000,000
Deferred tax charged directly to equity			(378,000,000)		27,933,000,000
Others (tax effect charged directly to equity due to the adoption of IFRS 9)			75,318,000,000		0
Sub total			257,455,000,000		41,822,000,000
Income tax expense	₩ 273,701,000,000	₩ 135,034,000,000	₩ 485,216,000,000	$ 436,424	₩ 320,933,000,000

Income tax expense_Relationship

Income tax expense_Relationship between the net income before income tax expense and the Income tax expense (Details) $ in Thousands, ₩ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2018KRW (₩)	Jun. 30, 2017KRW (₩)	Jun. 30, 2018KRW (₩)	Jun. 30, 2018USD ($)	Jun. 30, 2017KRW (₩)
Reconciliation of accounting profit multiplied by applicable tax rates [Abstract]
Net income before income tax expense		₩ 995,497	₩ 601,318	₩ 1,801,532	$ 1,620,374	₩ 1,429,948
Tax calculated at statutory tax rate	[1]			490,240		345,585
Adjustments
Effect of income that is exempt from taxation				(19,695)		(32,683)
Effect of expense that is not deductible in determining taxable profit				9,395		9,624
Adjustments recognized in the current period in relation to the current tax of prior periods				(3,632)		(4,919)
Others				8,908		3,326
Sub total				(5,024)		(24,652)
Income tax expense				₩ 485,216		₩ 320,933
Effective tax rate				26.90%	26.90%	22.40%
Description of applicable tax rate by taxable income	[1]			The applicable income tax rate; 1) 11% for below 200 million Won, 2) 22% for above 200 million Won and below 20 billion Won, 3) 24.2% for above 20 billion Won and below 300 billion Won, 4) 27.5% for above 300 billion Won.	The applicable income tax rate; 1) 11% for below 200 million Won, 2) 22% for above 200 million Won and below 20 billion Won, 3) 24.2% for above 20 billion Won and below 300 billion Won, 4) 27.5% for above 300 billion Won.	The applicable income tax rate; 1) 11% for below 200 million Won, 2) 22% for above 200 million Won and below 20 billion Won, 3) 24.2% for above 20 billion Won and below 300 billion Won, 4) 27.5% for above 300 billion Won.
[1]	The applicable income tax rate; 1) 11% for below 200 million Won, 2) 22% for above 200 million Won and below 20 billion Won, 3) 24.2% for above 20 billion Won and below 300 billion Won, 4) 27.5% for above 300 billion Won.

Income tax expense_Details of a

Income tax expense_Details of accumulated deferred tax charged directly to equity (Details) - KRW (₩) ₩ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Disclosure of deferred tax relating to items charged or credited directly to equity [Abstract]
Net gain on valuation of financial assets at FVTOCI	₩ 18,568
Loss on valuation of AFS securities		₩ (114,169)
Share of other comprehensive gain (loss) of joint ventures and associates	378	(954)
Foreign currency translation of foreign operations	6,852	15,855
Remeasurements of the net defined benefit liability	78,685	56,317
Gain (loss) on cash flow hedge	1,735	(248)
Total	₩ 106,218	₩ (43,199)

Earnings per share_Details of e

Earnings per share_Details of earnings per share (Details) ₩ / shares in Units, $ in Thousands, ₩ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018KRW (₩)₩ / sharesshares	Jun. 30, 2017KRW (₩)₩ / sharesshares	Jun. 30, 2018KRW (₩)₩ / sharesshares	Jun. 30, 2018USD ($)shares	Jun. 30, 2017KRW (₩)₩ / sharesshares
Basic earnings per share [Abstract]
Net income attributable to owners	₩ 716,142	₩ 460,888	₩ 1,305,878	$ 1,174,562	₩ 1,098,361
Dividends to hybrid securities | ₩	(37,748)	(41,557)	(75,603)		(90,823)
Net income attributable to common shareholders | ₩	₩ 678,394	₩ 419,331	₩ 1,230,275		₩ 1,007,538
Weighted average number of common shares outstanding | shares	673,000,000	673,000,000	673,000,000	673,000,000	673,000,000
Basic Earnings Per Share | ₩ / shares	₩ 1,008	₩ 623	₩ 1,828		₩ 1,497
Diluted earnings per share [Abstract]
Diluted earnings loss per share | ₩ / shares	₩ 1,008	₩ 623	₩ 1,828		₩ 1,497

Contingent liabilities and c236

Contingent liabilities and commitments_Details of contingent liabilities and commitments (Details) ₩ in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2018KRW (₩)	Dec. 31, 2017KRW (₩)
Disclosure of contingent liabilities [Line Items]
Total of guarantees		₩ 12,372,573	₩ 12,859,715
Loan commitments		98,251,006	80,760,325
Other commitments		₩ 5,942,784	₩ 4,546,090
Number of cases as plaintiffs	[1]	68	83
Number of cases as defendants	[1]	161	155
Amount of litigation as plaintiff		₩ 443,234	₩ 413,267
Amount of litigation as defendant		256,147	244,767
Allowance for litigations		19,887	₩ 9,277
Description of gain related to litigation settlement			The Group provides settlement services for payments in Korean Won to facilitate trade transactions between Korea and Iran. In connection with these services, the Group is currently being investigated by US government agencies including US prosecutors (United States Attorney’s Office and New York State Attorney General’s Office) as to whether the Group has violated United States laws by participating in prohibited transactions involving countries sanctioned by the US.
Confirmed guarantees
Disclosure of contingent liabilities [Line Items]
Total of guarantees		6,563,000	₩ 6,875,021
Guarantee for loans
Disclosure of contingent liabilities [Line Items]
Total of guarantees		141,193	157,299
Acceptances
Disclosure of contingent liabilities [Line Items]
Total of guarantees		333,365	320,519
Guarantees in acceptances of imported goods
Disclosure of contingent liabilities [Line Items]
Total of guarantees		106,675	108,238
Other confirmed guarantees
Disclosure of contingent liabilities [Line Items]
Total of guarantees		5,981,767	6,288,965
Unconfirmed guarantees
Disclosure of contingent liabilities [Line Items]
Total of guarantees		4,510,070	4,526,593
Local letter of credit
Disclosure of contingent liabilities [Line Items]
Total of guarantees		365,302	383,117
Letter of credit
Disclosure of contingent liabilities [Line Items]
Total of guarantees		3,207,797	3,637,787
Other unconfirmed guarantees
Disclosure of contingent liabilities [Line Items]
Total of guarantees		936,971	505,689
Commercial paper purchase commitments and others
Disclosure of contingent liabilities [Line Items]
Total of guarantees		₩ 1,299,503	₩ 1,458,101
[1]	The number of lawsuits as of June 30, 2018 and December 31, 2017 does not include fraud lawsuits, etc. and those lawsuits that are filed only to extend the statute of limitation.

Related party transactions_Deta

Related party transactions_Details of transactions with related parties (Details) - KRW (₩)		6 Months Ended			12 Months Ended
		Jun. 30, 2018	Jun. 30, 2017		Dec. 31, 2017
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Payment guarantees to related parties		₩ 11,525,000,000			₩ 71,459,000,000
Description of changes of ownership interest of related party	[1],[2]	The entity is in scope for the associates due to contribution as of the year ended December 31, 2017. The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018.	The entity is in scope for the associates due to contribution as of the year ended December 31, 2017. The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018.
KDIC
Related party transactions [Abstract]
Interest expenses		₩ 0	₩ 15,331,000,000
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Description of nature of related party relationship			Corporation that has significant influence over the group		Corporation that has significant influence over the group
Description of changes of ownership interest of related party	[3]		As its ownership interest in the Group is lower than 20% as of December 31, 2017, it has been excluded from the corporation that have significant influence over the Group.		As its ownership interest in the Group is lower than 20% as of December 31, 2017, it has been excluded from the corporation that have significant influence over the Group.
Kumho Tires Co Inc
Outstanding balances for related party transactions [Abstract]
Loans		257,856,000,000			₩ 170,917,000,000
Allowance for credit loss		(62,957,000,000)			(156,712,000,000)
Deposits due to customers		482,000,000			666,000,000
Other liabilities		489,000,000			50,000,000
Related party transactions [Abstract]
Interest income		1,098,000,000	₩ 1,501,000,000
Fees income		0	6,000,000
Impairment losses due to credit loss (reversal of allowance for credit loss)		(93,755,000,000)	₩ 1,042,000,000
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Loan commitment		511,000,000			636,000,000
Import credit in foreign currencies and others		₩ 13,830,000,000			₩ 4,181,000,000
Description of nature of related party relationship		Associates	Associates		Associates
Woori Service Networks Co Ltd
Outstanding balances for related party transactions [Abstract]
Loans		₩ 22,000,000			₩ 45,000,000
Deposits due to customers		1,732,000,000			1,311,000,000
Other liabilities		339,000,000			357,000,000
Related party transactions [Abstract]
Interest expenses		7,000,000	₩ 13,000,000
Fees expenses		270,000,000	335,000,000
Other income		15,000,000	15,000,000
Other expenses		231,000,000	₩ 249,000,000
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Loan commitment		₩ 178,000,000			₩ 155,000,000
Description of nature of related party relationship		Associates	Associates		Associates
Korea Credit Bureau Co Ltd
Outstanding balances for related party transactions [Abstract]
Loans		₩ 4,000,000			₩ 6,000,000
Deposits due to customers		1,063,000,000			5,586,000,000
Other liabilities		6,000,000			54,000,000
Related party transactions [Abstract]
Interest expenses		21,000,000	₩ 38,000,000
Fees expenses		1,038,000,000	₩ 1,023,000,000
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Loan commitment		₩ 31,000,000			₩ 29,000,000
Description of nature of related party relationship		Associates	Associates		Associates
Korea Finance Security Co Ltd
Outstanding balances for related party transactions [Abstract]
Loans		₩ 42,000,000			₩ 56,000,000
Allowance for credit loss		(2,000,000)			0
Deposits due to customers		3,078,000,000			2,854,000,000
Other liabilities		4,000,000			7,000,000
Related party transactions [Abstract]
Interest expenses		4,000,000	₩ 5,000,000
Fees expenses		71,000,000	0
Impairment losses due to credit loss (reversal of allowance for credit loss)		2,000,000	₩ 0
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Loan commitment		₩ 218,000,000			₩ 204,000,000
Description of nature of related party relationship		Associates	Associates		Associates
Chin Hung International Inc
Outstanding balances for related party transactions [Abstract]
Loans		₩ 182,000,000			₩ 408,000,000
Allowance for credit loss		(24,000,000)			(22,000,000)
Deposits due to customers		61,551,000,000			46,220,000,000
Other liabilities		2,899,000,000			1,658,000,000
Related party transactions [Abstract]
Interest income		0	₩ 53,000,000
Interest expenses		21,000,000	13,000,000
Fees income		0	1,000,000
Impairment losses due to credit loss (reversal of allowance for credit loss)		2,000,000	₩ (4,270,000,000)
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Loan commitment		₩ 32,117,000,000			₩ 31,891,000,000
Description of nature of related party relationship		Associates	Associates		Associates
Poonglim Industrial Co Ltd
Outstanding balances for related party transactions [Abstract]
Deposits due to customers		₩ 0			₩ 4,000,000
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Description of nature of related party relationship			Associates		Associates
Description of changes of ownership interest of related party	[4]		The Group did not have significant influence over the entity due to the fact that the entity was going through workout process under receivership, and thus the entity was excluded from the investment in associates		The Group did not have significant influence over the entity due to the fact that the entity was going through workout process under receivership, and thus the entity was excluded from the investment in associates
STX Engine Co Ltd
Outstanding balances for related party transactions [Abstract]
Loans		106,176,000,000			₩ 106,176,000,000
Allowance for credit loss		(88,734,000,000)			(88,734,000,000)
Deposits due to customers		18,092,000,000			18,092,000,000
Other liabilities		29,000,000			29,000,000
Related party transactions [Abstract]
Interest income	[2]	333,000,000	₩ 672,000,000
Interest expenses	[2]	86,000,000	72,000,000
Fees income		0	28,000,000	[2]
Impairment losses due to credit loss (reversal of allowance for credit loss)		₩ (88,734,000,000)	₩ (1,835,000,000)
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Import credit in foreign currencies and others	[2]				₩ 68,858,000,000
Description of nature of related party relationship		Associates	Associates		Associates
Description of changes of ownership interest of related party	[2]	The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018.	The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018		The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018
STX Corporation
Outstanding balances for related party transactions [Abstract]
Loans		₩ 73,519,000,000			₩ 47,711,000,000
Allowance for credit loss		(49,734,000,000)			(31,210,000,000)
Deposits due to customers		2,130,000,000			77,555,000,000
Other liabilities		131,000,000			80,000,000
Related party transactions [Abstract]
Interest income		0	₩ 219,000,000
Interest expenses		2,000,000	4,000,000
Fees income		0	58,000,000
Impairment losses due to credit loss (reversal of allowance for credit loss)		18,524,000,000	₩ (59,507,000,000)
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Loan commitment		132,000,000			53,000,000
Import credit in foreign currencies and others		₩ 14,914,000,000			₩ 17,557,000,000
Description of nature of related party relationship		Associates	Associates		Associates
K BANK Co Ltd
Outstanding balances for related party transactions [Abstract]
Loans		₩ 103,000,000			₩ 212,000,000
Related party transactions [Abstract]
Fees income		514,000,000	₩ 396,000,000
Other income		5,000,000	1,051,000,000
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Loan commitment		₩ 101,000,000	₩ 0
Description of nature of related party relationship		Associates	Associates		Associates
Well to Sea No.3 Private Equity Fund
Outstanding balances for related party transactions [Abstract]
Loans		₩ 85,000,000,000			₩ 73,810,000,000
Allowance for credit loss		(85,000,000)			(39,000,000)
Deposits due to customers		3,213,000,000			61,000,000
Other liabilities		69,000,000			27,000,000
Related party transactions [Abstract]
Interest income		1,288,000,000	₩ 0
Interest expenses		4,000,000	0
Impairment losses due to credit loss (reversal of allowance for credit loss)		46,000,000	₩ 0
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Loan commitment		₩ 225,000,000,000			₩ 236,190,000,000
Description of nature of related party relationship		Associates	Associates		Associates
Description of changes of ownership interest of related party	[5]	Due to capital contribution for the year ended December 31, 2017, the entity has been included in the investment in associates.	Due to capital contribution for the year ended December 31, 2017, the entity has been included in the investment in associates.		Due to capital contribution for the year ended December 31, 2017, the entity has been included in the investment in associates.
Others
Outstanding balances for related party transactions [Abstract]
Loans		₩ 260,000,000			₩ 499,000,000
Allowance for credit loss		(235,000,000)			(471,000,000)
Other assets		1,000,000			1,000,000
Deposits due to customers		6,369,000,000			2,906,000,000
Other liabilities		153,000,000			₩ 73,000,000
Related party transactions [Abstract]
Interest expenses		22,000,000	₩ 5,000,000
Impairment losses due to credit loss (reversal of allowance for credit loss)		(236,000,000)	(10,000,000)
Other income		₩ 6,000,000	₩ 0
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Description of nature of related party relationship		Associates	Associates		Associates
Description of other related parties with outstanding balances	[6]	Others include Saman Corporation, Kyesan Engineering Co., Ltd., Hyunwoo International Co., Ltd., DAEA SNC Co., Ltd. and others as of June 30, 2018 and December 31, 2017.			Others include Saman Corporation, Kyesan Engineering Co., Ltd., Hyunwoo International Co., Ltd., DAEA SNC Co., Ltd. and others as of June 30, 2018 and December 31, 2017
Description of other related parties with transactions	[7]	Others include the amount transacted with Saman Corporation, Kyesan Engineering Co., Ltd., Hyunwoo International Co., Ltd., DAEA SNC Co., Ltd. and others for the six months ended June 30, 2018 and 2017.	Others include the amount transacted with Saman Corporation, Kyesan Engineering Co., Ltd., Hyunwoo International Co., Ltd., DAEA SNC Co., Ltd. and others for the six months ended June 30, 2018 and 2017.
Woori Blackstone Korea Opportunity Private Equity Fund No.1
Related party transactions [Abstract]
Fees income		₩ 0	₩ 29,000,000
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Description of changes of ownership interest of related party	[8]		Due to disposition previous year, the entity is not in scope for associate.		Due to disposition previous year, the entity is not in scope for associate.
Samho International Co Ltd
Related party transactions [Abstract]
Interest income		0	₩ 364,000,000	[2]
Interest expenses		0	214,000,000	[2]
Fees income		0	6,000,000	[2]
Impairment losses due to credit loss (reversal of allowance for credit loss)		₩ 0	₩ (116,000,000)
Disclosure of outstanding commitments made by entity related party transactions [Abstract]
Description of changes of ownership interest of related party	[2]		The entity was sold after it was transferred to assets held for sale and was excluded from the investment in associates for the year ended December 31, 2017.		The entity was sold after it was transferred to assets held for sale and was excluded from the investment in associates for the year ended December 31, 2017.
[1]	The entity is in scope for the associates due to contribution as of the year ended December 31, 2017.
[2]	The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018.
[3]	As its ownership interest in the Group is lower than 20% as of December 31, 2017, it has been excluded from the corporation that have significant influence over the Group.
[4]	The Group did not have significant influence over the entity due to the fact that the entity was going through workout process under receivership, and thus the entity was excluded from the investment in associates
[5]	Due to capital contribution for the year ended December 31, 2017, the entity has been included in the investment in associates.
[6]	Others include Saman Corporation, Kyesan Engineering Co., Ltd., Hyunwoo International Co., Ltd., DAEA SNC Co., Ltd. and others as of June 30, 2018 and December 31, 2017.
[7]	Others include the amount transacted with Saman Corporation, Kyesan Engineering Co., Ltd., Hyunwoo International Co., Ltd., DAEA SNC Co., Ltd. and others for the six months ended June 30, 2018 and 2017.
[8]	Due to disposition previous year, the entity is not in scope for associate.

Related party transactions_Majo

Related party transactions_Major loan and borrowing transactions with related parties (Details) - KRW (₩)		6 Months Ended				12 Months Ended
		Jun. 30, 2018		Jun. 30, 2017		Dec. 31, 2017
Disclosure of major loan and borrowing transactions between related parties [Abstract]
Beginning balance of Major loan transations with KumhoTires Co Inc		₩ 57,470,000,000		₩ 50,413,000,000		₩ 50,413,000,000
Beginning balance of Major loan transations with Well to Sea No. 3 Private Equity Fund	[1]	73,810,000,000
Beginning balance of Major loan transations with STX Engine Co Ltd	[2]	39,886,000,000		44,797,000,000		44,797,000,000
Beginning balance of major borrowing transactions		0
Increase (decrease) of major loan transactions with related parties through other changes
Loan to Well to Sea No. 3 Private Equity Fund	[1]	11,190,000,000
Collection from KumhoTires Co Inc		7,057,000,000
Collection from STX Engine Co Ltd	[2]	2,177,000,000		7,088,000,000
Others for STX Engine Co Ltd	[2]	(37,709,000,000)
Ending balance of Major loan transations with KumhoTires Co Inc		50,413,000,000	[3]	50,413,000,000	[3]	57,470,000,000
Ending balance of Major loan transations with Well to Sea No. 3 Private Equity Fund	[1]	85,000,000,000	[3]			73,810,000,000
Ending balance of Major loan transations with STX Engine Co Ltd	[2]			₩ 37,709,000,000	[3]	39,886,000,000
Ending balance of major borrowing transactions		₩ 0				₩ 0
Description of nature of major loan and borrowing transactions with related parties	[3]	Settlement payment caused in operation among the related parties were excluded, and in the case of a limited loan, it was presented as a net increase (decrease).		Settlement payment caused in operation among the related parties were excluded, and in the case of a limited loan, it was presented as a net increase (decrease).
Description of changes of ownership interest of related party	[1],[2]	The entity is in scope for the associates due to contribution as of the year ended December 31, 2017. The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018.		The entity is in scope for the associates due to contribution as of the year ended December 31, 2017. The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018.
[1]	The entity is in scope for the associates due to contribution as of the year ended December 31, 2017.
[2]	The entity was sold after it was transferred to assets held for sale for the year ended December 31, 2017 and was excluded from the investment in associates as of June 30, 2018.
[3]	Settlement payment caused in operation among the related parties were excluded, and in the case of a limited loan, it was presented as a net increase (decrease).

Related party transactions_Comp

Related party transactions_Compensation for key management (Details) - KRW (₩)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [Abstract]
Short term benefits	₩ 6,023,000,000	₩ 6,524,000,000
Severance payments	280,000,000	280,000,000
Total	6,303,000,000	₩ 6,804,000,000
Outstanding receivables from transaction with key management	2,155,000,000
Outstanding payables from transaction with key management	6,946,000,000
Loss allowance related to outstanding balances of transactions with key mangement personnel	0
Impairment loss reversal of impairment loss recognised related to outstanding balances of transactions with key mangement personnel	₩ 0
Description of nature of key management personnel	Key management includes registered executives and non-registered executives.	Key management includes registered executives and non-registered executives.

Business combination_Details of

Business combination_Details of Business combination (Details) ₩ in Millions	6 Months Ended
	Jun. 30, 2018KRW (₩)
Disclosure of detailed information about business combination [Abstract]
Name of acquiree	Vision Fund Cambodia
Description of acquiree	The Group changed its name to WB Finance Co., Ltd..
Date of acquisition	Jun. 21, 2018
Percentage of voting equity interests acquired	100.00%
Explanation of effect of changes in composition of entity during interim period	In order to expand Cambodia’s retail business, the Group had acquired 100% ownership of Vision Fund Cambodia on June, 2018. And The Group changed its name to WB Finance Co., Ltd..
Description of primary reasons for business combination	For expand Cambodia’s retail business
Description of how acquirer obtained control of acquiree	The Group had acquired 100% ownership.
Consideration transferred:
Cash and Cash equivalents	₩ 88,216
Identifiable assets and liabilities recognized
Cash and Cash equivalents	16,657
Financial assets at FVTOCI	17
Loans and other financial assets at amortized cost	205,451
Premises and equipment	1,630
Intangible assets	763
Current tax assets	173
Deferred tax assets	1,381
Other assets	1,510
Asset total	227,582
Deposits due to customers	54,615
Borrowings	120,644
Other financial liabilities	6,149
Current tax liabilities	640
Other liabilities	4,724
Liabilities total	186,772
Identifiable net fair value	40,810
Goodwill	₩ 47,406	[1]
[1]	Identifying the intangible assets and measuring the fair value of identifiable assets acquired are incomplete as the acquisition date was June 21, 2018. The amount of Goodwill could change due to the result of the measurement of the identifiable assets and liabilities.

Establishment of a financial241

Establishment of a financial hoding company and plan of stock transfer_Description of establishment of a financial hoding company and plan of stock transfer (Details)	6 Months Ended
	Jun. 30, 2018
Schedule of investments [Abstract]
Description of establishment of holding company in progress	The Group's board of directors held a meeting on June 19, 2018, approving the plan to transfer shares which was formulated to facilitate the establishment of a financial holding company by means of comprehensive share transfer. In relation to the establishment of the financial holding company, the Group is currently undertaking processes to obtain approval from the Financial Services Committee.
Description of subsidiaries of holding company to be established	The six companies that are subject to the share transfer plan include the Bank, Woori FIS Co., Ltd., Woori Finance Research Institute Co., Ltd., Woori Credit Information Co., Ltd., Woori Fund Service Co., Ltd., Woori Private Equity Asset Management Co., Ltd. After the Group obtains approval from the Financial Services Committee, the Group is planning to establish the financial holding company during the first half of 2019 through processes such as annual shareholders' meeting. Following the establishment of the financial holding company, the six companies mentioned above will become fully owned subsidiaries of the holding company.
Description of listing on stock exchange market due to holding company to be established	After the financial holding company is established, the shares of the Group will be delisted from the Korea Stock Exchange and New York Stock Exchange during the first half of the 2019, and the shares of the newly established financial holding company will be listed on both Korea Stock Exchange and New York Stock Exchange.