Mizuho Financial (MFG) 6-K 26 Dec 19 2019 Q2 Current report (foreign) Financial data

Cover Page

Cover Page	6 Months Ended
	Sep. 30, 2019
Cover [Abstract]
Document Type	6-K
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Entity Registrant Name	MIZUHO FINANCIAL GROUP INC
Entity Central Index Key	0001335730
Current Fiscal Year End Date	--03-31

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - JPY (¥) ¥ in Millions	Sep. 30, 2019	Mar. 31, 2019
Assets:
Cash and due from banks	¥ 1,496,885	¥ 1,404,008
Interest-bearing deposits in other banks	42,484,121	44,268,731
Call loans and funds sold	1,036,493	763,453
Receivables under resale agreements	13,660,282	12,997,424
Receivables under securities borrowing transactions	3,061,204	2,578,134
Trading account assets	24,950,040	21,018,230
Investments (Note 3):
Available-for-sale securities (including assets pledged that secured parties are permitted to sell or repledge of ¥1,132,602 million at March 31, 2019 and ¥1,297,077 million at September 30, 2019)	17,690,583	18,133,916
Held-to-maturity securities (including assets pledged that secured parties are permitted to sell or repledge of ¥476,146 million at March 31, 2019 and ¥420,401 million at September 30, 2019)	1,064,376	1,604,104
Equity securities	3,761,213	4,034,609
Other investments	408,235	389,740
Loans (Notes 4 and 5)	83,856,191	82,799,943
Allowance for loan losses	(291,422)	(307,201)
Loans, net of allowance	83,564,769	82,492,742
Premises and equipment—net	1,854,130	1,900,952
Due from customers on acceptances	207,389	187,137
Accrued income	312,657	342,845
Goodwill	95,143	95,151
Intangible assets	69,628	74,240
Deferred tax assets	47,260	49,775
Other assets (Note 6)	6,008,055	5,276,004
Total assets	201,772,463	197,611,195
Liabilities and equity:
Noninterest-bearing deposits	25,314,631	23,844,639
Interest-bearing deposits	84,703,684	84,019,038
Noninterest-bearing deposits	2,175,769	1,793,803
Interest-bearing deposits	27,598,940	28,639,436
Due to trust accounts	319,966	312,347
Call money and funds purchased	2,139,925	2,841,932
Payables under repurchase agreements (Note 19)	17,339,783	14,640,369
Payables under securities lending transactions	1,857,118	1,797,737
Other short-term borrowings	1,607,881	1,994,826
Trading account liabilities	11,973,917	10,120,968
Bank acceptances outstanding	207,389	187,137
Income taxes payable	69,454	58,688
Deferred tax liabilities	100,235	108,120
Accrued expenses	266,198	288,556
Long-term debt (including liabilities accounted for at fair value of ¥2,433,294 million at March 31, 2019 and ¥2,662,041 million at September 30, 2019) (Note 17)	10,427,340	11,529,400
All other liabilities	6,183,660	5,932,706
Total	192,285,890	188,109,702
Commitments and contingencies (Note 14)
MHFG shareholders' equity:
Common stock (Note 7)-no par value, authorized 48,000,000,000 shares at March 31, 2019 and September 30, 2019, and issued 25,392,498,945 shares at March 31, 2019 and September 30, 2019	5,827,955	5,829,657
Retained earnings	2,858,773	2,740,545
Accumulated other comprehensive income, net of tax (Note 8)	106,715	164,021
Less: Treasury stock, at cost-Common stock 33,962,404 shares at March 31, 2019, and 34,477,267 shares at September 30, 2019	(6,810)	(7,704)
Total MHFG shareholders' equity	8,786,633	8,726,519
Noncontrolling interests	699,940	774,974
Total equity	9,486,573	9,501,493
Total liabilities and equity	201,772,463	197,611,195
Consolidated VIEs
Assets:
Cash and due from banks	28,183	29,972
Interest-bearing deposits in other banks	20,045	31,676
Call loans and funds sold	371,404	115,199
Trading account assets	2,368,739	2,456,198
Investments (Note 3):
Investments	56,723	52,493
Loans, net of allowance	2,424,202	2,359,669
Other assets (Note 6)	669,846	1,003,133
Total assets	5,939,142	6,048,340
Liabilities and equity:
Payables under securities lending transactions	95,206	108,038
Other short-term borrowings	32,759	23,495
Trading account liabilities	22,440
Long-term debt (including liabilities accounted for at fair value of ¥2,433,294 million at March 31, 2019 and ¥2,662,041 million at September 30, 2019) (Note 17)	332,685	344,526
All other liabilities	1,118,917	1,523,791
Total	¥ 1,602,007	¥ 1,999,850

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - JPY (¥) ¥ in Millions	Sep. 30, 2019	Mar. 31, 2019
Trading account assets, assets pledged that secured parties are permitted to sell or repledge	¥ 4,626,086	¥ 3,244,305
Available-for-sale securities, assets pledged that secured parties are permitted to sell or repledge	1,297,077	1,132,602
Held-to-maturity securities, assets pledged that secured parties are permitted to sell or repledge	420,401	476,146
Long-term debt, liabilities accounted for at fair value	¥ 2,662,041	¥ 2,433,294
Common stock, par value	¥ 0	¥ 0
Common stock, authorized	48,000,000,000	48,000,000,000
Common stock, issued	25,392,498,945	25,392,498,945
Treasury stock, shares	34,477,267	33,962,404

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - JPY (¥) ¥ in Millions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Interest and dividend income:
Loans, including fees		¥ 719,443	¥ 655,981
Investments:
Interest		52,249	64,780
Dividends		36,109	43,936
Trading account assets		108,881	113,687
Call loans and funds sold		2,963	2,121
Receivables under resale agreements and securities borrowing transactions		150,728	106,246
Deposits in other banks		56,981	55,039
Total interest and dividend income		1,127,354	1,041,790
Interest expense:
Deposits		335,290	270,721
Trading account liabilities		28,794	24,251
Call money and funds purchased		4,771	4,914
Payables under repurchase agreements and securities lending transactions		197,410	166,042
Other short-term borrowings		15,855	14,531
Long-term debt		98,502	106,608
Total interest expense		680,622	587,067
Net interest income		446,732	454,723
Provision (credit) for loan losses (Note 5)		13,773	(13,280)
Net interest income after provision (credit) for loan losses		432,959	468,003
Noninterest income (Note 16):
Fee and commission income		403,992	413,727
Foreign exchange gains (losses)—net	[1]	27,923	44,718
Trading account gains (losses)—net	[2]	395,405	64,956
Investment gains (losses)—net:
Debt securities	[1]	31,092	2,485
Equity securities	[1]	(126,648)	306,788
Equity in earnings (losses) of equity method investees—net	[1]	22,066	22,627
Gains on disposal of premises and equipment	[1]	1,693	4,305
Other noninterest income	[2]	34,839	48,950
Total noninterest income		790,362	908,556
Noninterest expenses:
Salaries and employee benefits		334,041	342,686
General and administrative expenses		314,840	359,358
Occupancy expenses		103,693	93,921
Fee and commission expenses		101,175	98,779
Provision (credit) for losses on off-balance-sheet instruments		(8,248)	(9,877)
Other noninterest expenses		67,364	74,042
Total noninterest expenses		912,865	958,909
Income before income tax expense		310,456	417,650
Income tax expense (Note 11)		83,120	85,705
Net income	[3]	227,336	331,945
Less: Net income attributable to noncontrolling interests		14,352	46,675
Net income attributable to MHFG shareholders		¥ 212,984	¥ 285,270
Earnings per common share (Note 10):
Basic net income per common share		¥ 8.40	¥ 11.25
Diluted net income per common share		8.40	11.25
Dividends per common share		¥ 3.75	¥ 3.75
[1]	These amounts are revenues from contracts that do not meet the scope of ASC 606.
[2]	Part of these amounts are considered to be revenues from contracts that are within the scope of ASC 606.
[3]	The amounts that have been reclassified out of Accumulated other comprehensive income, net of tax into net income are presented in Note 8 “Accumulated other comprehensive income, net of tax”.

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - JPY (¥) ¥ in Millions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Net income	[1]	¥ 227,336	¥ 331,945
Other comprehensive income (loss), net of tax		(56,583)	(19,030)
Total comprehensive income		170,753	312,915
Less: Total comprehensive income attributable to noncontrolling interests		14,023	46,482
Total comprehensive income attributable to MHFG shareholders		¥ 156,730	¥ 266,433
[1]	The amounts that have been reclassified out of Accumulated other comprehensive income, net of tax into net income are presented in Note 8 “Accumulated other comprehensive income, net of tax”.

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - JPY (¥) ¥ in Millions	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income		Treasury Stock	Parent	Noncontrolling Interest
Balance at beginning of period at Mar. 31, 2018		¥ 5,826,383	¥ 1,306,141	¥ 1,741,894		¥ (5,997)		¥ 635,279
Cumulative effect of change in accounting principles at Mar. 31, 2018			1,537,322	(1,535,142)	[1]			(616)
Issuance of new shares of common stock due to exercise of stock acquisition rights		438
Purchases of treasury stock						(2,857)
Balance at beginning of period, adjusted at Mar. 31, 2018			2,843,463	206,752				634,663
Performance-based stock compensation program		(1,053)
Disposal of treasury stock						965
Net income attributable to MHFG shareholders	¥ 285,270		285,270
Change during period	(19,030)			(18,837)
Other		2,994
Transactions between the MHFG Group and the noncontrolling interest shareholders								117,649
Dividends paid to noncontrolling interests								(9,291)
Dividends declared			(95,187)
Net income attributable to noncontrolling interests	(46,675)							46,675
Other								(193)
Balance at end of fiscal year at Sep. 30, 2018	9,831,837	5,828,762	3,033,546	187,915		(7,889)	¥ 9,042,334	789,503
Balance at beginning of period at Mar. 31, 2019	9,501,493	5,829,657	2,740,545	164,021		(7,704)		774,974
Cumulative effect of change in accounting principles at Mar. 31, 2019			1,052	(1,052)	[1]
Purchases of treasury stock						(1,851)
Balance at beginning of period, adjusted at Mar. 31, 2019			2,741,597	162,969				774,974
Performance-based stock compensation program		(806)
Disposal of treasury stock						2,745
Net income attributable to MHFG shareholders	212,984		212,984
Change during period	(56,583)			(56,254)
Other		(896)	(611)
Transactions between the MHFG Group and the noncontrolling interest shareholders								(79,439)
Dividends paid to noncontrolling interests								(9,618)
Dividends declared			(95,197)
Net income attributable to noncontrolling interests	(14,352)							14,352
Other								(329)
Balance at end of fiscal year at Sep. 30, 2019	¥ 9,486,573	¥ 5,827,955	¥ 2,858,773	¥ 106,715		¥ (6,810)	¥ 8,786,633	¥ 699,940
[1]	See Note 2 “Recently issued accounting pronouncements” for further details of the cumulative-effect adjustment for AOCI.

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - JPY (¥) ¥ in Millions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income	[1]	¥ 227,336	¥ 331,945
Less: Net income attributable to noncontrolling interests		14,352	46,675
Net income attributable to MHFG shareholders		212,984	285,270
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization		120,369	162,433
Provision (credit) for loan losses		13,773	(13,280)
Investment losses (gains)—net		95,556	(309,273)
Equity in losses (earnings) of equity method investees—net	[2]	(22,066)	(22,627)
Foreign exchange losses (gains)—net		(172,215)	288,705
Deferred income tax expense (benefit)		(5,317)	(28,961)
Net change in trading account assets		(3,753,226)	935,498
Net change in trading account liabilities		2,138,290	(3,437,556)
Net change in loans held for sale		17,427	44,830
Net change in accrued income		24,548	(20,565)
Net change in accrued expenses		(5,248)	34,490
Other—net		122,946	180,989
Net cash used in operating activities		(1,212,179)	(1,900,047)
Cash flows from investing activities:
Proceeds from sales of Available-for-sale securities	[3]	15,661,178	13,698,688
Proceeds from sales of Equity securities	[4]	1,177,962
Proceeds from maturities of Available-for-sale securities	[3]	8,454,526	8,075,748
Proceeds from maturities of Held-to-maturity securities		525,912	418,332
Purchases of Available-for-sale securities	[3]	(24,330,083)	(21,707,934)
Purchases of Equity securities	[4]	(1,209,953)
Proceeds from sales of loans		878,108	153,856
Net change in loans		(3,054,528)	(625,828)
Net change in call loans and funds sold, and receivables under resale agreements and securities borrowing transactions		(2,127,069)	165,558
Proceeds from sales of premises and equipment		8,748	6,764
Purchases of premises and equipment		(81,427)	(63,855)
Net cash provided by (used in) investing activities		(4,096,626)	121,329
Cash flows from financing activities:
Net change in deposits		2,848,039	(3,964,784)
Net change in call money and funds purchased, and payables under repurchase agreements and securities lending transactions		2,549,230	3,951,434
Net change in due to trust accounts		7,619	(26,912)
Net change in other short-term borrowings		(358,650)	10,760
Proceeds from issuance of long-term debt		1,223,618	1,286,316
Repayment of long-term debt		(2,195,976)	(984,642)
Proceeds from noncontrolling interests		33,009	140,068
Payments to noncontrolling interests		(105,424)
Proceeds from issuance of common stock			3
Proceeds from sales of treasury stock		1,515	933
Purchases of treasury stock		(1,436)	(2,102)
Dividends paid		(95,165)	(95,163)
Dividends paid to noncontrolling interests		(9,618)	(9,291)
Net cash provided by financing activities		3,896,761	306,620
Effect of exchange rate changes on cash and cash equivalents		(279,689)	321,775
Net increase decrease in cash and cash equivalents	[5]	(1,691,733)	(1,150,323)
Cash and cash equivalents at beginning of period	[5]	45,672,739	48,170,921
Cash and cash equivalents at end of period	[5]	43,981,006	47,020,598
Noncash investing activities:
Transfer of loans into loans held-for-sale		¥ 64,996	¥ 5,675
[1]	The amounts that have been reclassified out of Accumulated other comprehensive income, net of tax into net income are presented in Note 8 “Accumulated other comprehensive income, net of tax”.
[2]	These amounts are revenues from contracts that do not meet the scope of ASC 606.
[3]	Proceeds from sales and maturities of Available-for-sale securities as well as Purchases of Available-for-sale securities include cash activity related to Other investments for the six months ended September 30 2018, the amounts of which are not significant.
[4]	Proceeds from sales of Equity securities as well as Purchases of Equity securities include cash activity related to Other investments for the six months ended September 30 2019, the amounts of which are not significant.
[5]	Cash and cash equivalents consists of Cash and due from banks and Interest-bearing deposits in other banks. Cash deposited with central banks that must be maintained to meet minimum regulatory requirements is classified as restricted cash and included in Cash and cash equivalents.

Basis of presentation

Basis of presentation	6 Months Ended
	Sep. 30, 2019
Basis of presentation	1. Basis of presentation Mizuho Financial Group, Inc. (“MHFG”) is a joint stock corporation with limited liability under the laws of Japan. MHFG, through its subsidiaries (“the MHFG Group”, or “the Group”), provides domestic and international financial services in Japan and other countries. For a discussion of the Group’s segment information, see Note 20 “Business segment information”. MHFG and its domestic subsidiaries as well as its foreign subsidiaries maintain their accounting records in accordance with the accounting standards of Japan and those standards of the countries in which they are domiciled. Certain adjustments and reclassifications have been incorporated in the accompanying consolidated financial statements to conform them to the accounting principles generally accepted in the United States of America (“U.S. GAAP”). The consolidated financial statements are stated in Japanese yen, the currency of the country in which MHFG is incorporated and principally operates. The accompanying consolidated financial statements include the accounts of MHFG and its subsidiaries. MHFG’s interim financial reporting period ends on September 30 and certain subsidiaries’ interim financial reporting periods end on June 30. The effect on the MHFG Group’s consolidated financial statements of all material events occurring at these subsidiaries through the date of each of the periods presented in the consolidated financial statements has been considered for adjustment and/or disclosure. When determining whether to consolidate investee entities, the MHFG Group performs an analysis of the facts and circumstances of the particular relationships between the MHFG Group and the investee entities as well as the ownership of voting shares. The consolidated financial statements also include the accounts of VIEs for which MHFG or its subsidiaries have been determined to be the primary beneficiary in accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 810, “Consolidation” (“ASC 810”). All significant intercompany transactions and balances have been eliminated upon consolidation. The MHFG Group accounts for investments in entities over which it has significant influence by using the equity method of accounting. These investments are included in Other investments and the Group’s proportionate share of income or loss is included in Equity in earnings (losses) of equity method investees—net. Certain comparative amounts for the prior period have been reclassified in order to conform to the current period’s presentation. The unaudited consolidated financial statements should be read in conjunction with the audited financial statements and related notes thereto included in the annual financial statements for the fiscal year ended March 31, 2019. Certain financial information that is normally included in annual financial statements prepared in accordance with U.S. GAAP, but is not required for interim reporting purposes, has been condensed or omitted. Use of estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect reported amounts and related disclosures. Specific areas, among others, requiring the application of management’s estimates and judgment include assumptions pertaining to the allowance for loan losses, allowance for losses on off-balance-sheet Leases The MHFG Group, as a lessee, recognizes liabilities to make lease payments and right-of-use (“ROU”) assets representing its right to use the underlying assets for the lease term. The lease terms include periods covered by options to extend or terminate the lease that the Group is reasonably certain to exercise. The Group uses its incremental borrowing rates at the lease commencement to determine the lease liability, which is measured at the present value of future lease payments, when the rate implicit in the lease is not readily determinable. The Group has elected not to separate lease and non-lease components of a contract that is or contains a lease for its equipment leases. The Group has elected not to recognize ROU assets and liabilities for leases with terms of twelve months or less. For operating leases, the ROU assets and related liabilities are included in Other assets and Other liabilities, respectively, on the consolidated balance sheets. Expenses are recognized on a straight-line basis over the lease term and are included in Occupancy expenses on the consolidated statements of income. Variable lease payments not included in the ROU assets or the lease liabilities are recognized as incurred in Occupancy expenses. For finance leases, ROU assets and related liabilities are included in Premises and equipment and Long-term debt, respectively, on the consolidated balance sheets.

Recently issued accounting pron

Recently issued accounting pronouncements	6 Months Ended
	Sep. 30, 2019
Recently issued accounting pronouncements	2. Recently issued accounting pronouncements Recently adopted accounting pronouncements In January 2016, the FASB issued ASU No.2016-01, 825-10)—Recognition No.2016-01”). No.2016-01, Available-for-sale non-marketable No.2016-01, No.2016-01, Accumulated other comprehensive income, net of tax (“ ”) ” In February 2016, the FASB issued ASU No.2016-02, No.2016-02”). ROU No.2016-02 ROU In August 2017, the FASB issued ASU No.2017-12, No.2017-12”). No.2017-12 No.2017-12 In February 2018, the FASB issued ASU No.2018-02, (“ASU No.2018-02”). No.2018-02 No.2018-02 In October 2018, the FASB issued ASU No.2018-16, No.2018-16”). No.2018-16 No.2018-16 Accounting pronouncements issued but not yet effective as of September 30, 2019 In June 2016, the FASB issued ASU No.2016-13, No.2016-13”). available-for-sale No.2019-04, Losses” (“ASU No.2019-04”). ies No.2019-05, No.2019-05”). In November 2019, the FASB issued ASU No.2019-11, “Codification Improvements to Topic 326, Financial Instruments—Credit Losses (Topic 326) ” (“ASU No.2019-11”). The ASU clarifies or addresses specific issues about certain aspects of the amendments in ASU No.2016-13, such as expected recoveries for purchased financial assets with credit deterioration and financial assets secured by collateral maintenance provisions. The ASUs are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and will be applied using a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. Early application is permitted as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The MHFG Group expects to adopt ASU No.2016-13, 2019-04, 2019-05, 2019- 11 No.2016-13, 2019-04, 2019-0 5, 2019- 11 , ing The Gro up is In January 2017, the FASB issued ASU No.2017-04, No.2017-04”). No.2017-04 No.2017-04 In August 2018, the FASB issued ASU No.2018-13, No.2018-13”). No.2018-13 No.2018-13 In August 2018, the FASB issued ASU No.2018-14, 715-20)—Disclosure No.2018-14”). No.2018-14 No.2018-14 In October 2018, the FASB issued ASU No.2018-17, No.2018-17”). No.2018-17 No.2018-17

Investments

Investments	6 Months Ended
	Sep. 30, 2019
Investments	3. Investments Available-for-sale held-to-maturity The amortized cost, gross unrealized gains and losses, and fair value of available-for-sale held-to-maturity Amortized cost Gross unrealized gains Gross unrealized losses Fair value (in millions of yen) March 31, 2019 Available-for-sale Debt securities: Japanese government bonds 11,888,510 11,259 2,998 11,896,771 Japanese local government bonds 208,308 1,671 87 209,892 U.S. Treasury bonds and federal agency securities 1,008,903 644 231 1,009,316 Other foreign government bonds 1,341,564 758 455 1,341,867 Agency mortgage-backed securities (1) 530,540 14,524 593 544,471 Residential mortgage-backed securities 99,904 1,420 191 101,133 Commercial mortgage-backed securities 495,313 4,914 104 500,123 Japanese corporate bonds and other debt securities 1,743,309 7,686 1,561 1,749,434 Foreign corporate bonds and other debt securities (2) 778,088 3,047 226 780,909 Total 18,094,439 45,923 6,446 18,133,916 Held-to-maturity Debt securities: Japanese government bonds 1,119,899 19,907 — 1,139,806 Agency mortgage-backed securities (3) 484,205 — 14,423 469,782 Total 1,604,104 19,907 14,423 1,609,588 September 30, 2019 Available-for-sale Debt securities: Japanese government bonds 11,419,982 11,130 4,247 11,426,865 Japanese local government bonds 234,345 986 169 235,162 U.S. Treasury bonds and federal agency securities 1,000,684 831 430 1,001,085 Other foreign government bonds 1,331,208 1,576 292 1,332,492 Agency mortgage-backed securities (1) 495,503 16,868 162 512,209 Residential mortgage-backed securities 85,672 1,694 152 87,214 Commercial mortgage-backed securities 543,378 5,850 117 549,111 Japanese corporate bonds and other debt securities 1,792,730 11,931 1,731 1,802,930 Foreign corporate bonds and other debt securities (2) 740,431 3,248 164 743,515 Total 17,643,933 54,114 7,464 17,690,583 Held-to-maturity Debt securities: Japanese government bonds 639,913 20,198 — 660,111 Agency mortgage-backed securities (3) 424,463 2 9,767 414,698 Total 1,064,376 20,200 9,767 1,074,809 Notes: (1) Agency mortgage-backed securities presented in this line consist of Japanese and Foreign agency mortgage-backed securities, of which the fair values were ¥517,330 million and ¥27,141 million, respectively, at March 31, 2019, and ¥ 512,144 65 (2) Other debt securities presented in this line primarily consist of Foreign negotiable certificates of deposit (“ NCDs”) and asset-backed securities (“ABS”), of which the total fair values were ¥246,503 million at March 31, 2019, and ¥ 226,899 (3) All Agency mortgage-backed securities presented in this line are Ginnie Mae securities. Contractual maturities The amortized cost and fair value of available-for-sale held-to-maturity Amortized cost Due in one year or less Due after one year through five years Due after five years through ten years Due after ten years Total (in millions of yen) Available-for-sale Debt securities: Japanese government bonds 5,907,368 4,501,734 1,010,880 — 11,419,982 Japanese local government bonds 9,207 148,811 73,113 3,214 234,345 U.S. Treasury bonds and federal agency securities 957,039 43,645 — — 1,000,684 Other foreign government bonds 1,077,745 253,463 — — 1,331,208 Agency mortgage-backed securities — — — 495,503 495,503 Residential mortgage-backed securities — — — 85,672 85,672 Commercial mortgage-backed securities 3,379 187,887 331,837 20,275 543,378 Japanese corporate bonds and other debt securities 94,985 863,381 526,430 307,934 1,792,730 Foreign corporate bonds and other debt securities 376,288 286,206 75,099 2,838 740,431 Total 8,426,011 6,285,127 2,017,359 915,436 17,643,933 Held-to-maturity Debt securities: Japanese government bonds 159,987 439,916 40,010 — 639,913 Agency mortgage-backed securities — — — 424,463 424,463 Total 159,987 439,916 40,010 424,463 1,064,376 Fair value Due in one year or less Due after one year through five years Due after five years through ten years Due after ten years Total (in millions of yen) Available-for-sale Debt securities: Japanese government bonds 5,911,536 4,507,477 1,007,852 — 11,426,865 Japanese local government bonds 9,253 149,149 73,418 3,342 235,162 U.S. Treasury bonds and federal agency securities 957,493 43,592 — — 1,001,085 Other foreign government bonds 1,078,329 254,163 — — 1,332,492 Agency mortgage-backed securities — — — 512,209 512,209 Residential mortgage-backed securities — — — 87,214 87,214 Commercial mortgage-backed securities 3,385 189,294 336,106 20,326 549,111 Japanese corporate bonds and other debt securities 95,179 865,299 528,669 313,783 1,802,930 Foreign corporate bonds and other debt securities 376,852 288,497 75,328 2,838 743,515 Total 8,432,027 6,297,471 2,021,373 939,712 17,690,583 Held-to-maturity Debt securities: Japanese government bonds 160,192 458,337 41,582 — 660,111 Agency mortgage-backed securities — — — 414,698 414,698 Total 160,192 458,337 41,582 414,698 1,074,809 Other-than-temporary impairment The MHFG Group performs periodic reviews to identify impaired securities in accordance with ASC 320, “Investments-Debt Securities” (“ASC 320”). For debt securities, in the cases where the MHFG Group has the intent to sell a debt security or more likely than not will be required to sell a debt security before the recovery of its amortized cost basis, the full amount of an other-than-temporary impairment loss is recognized immediately through earnings. In other cases, the MHFG Group evaluates expected cash flows to be received and determines if a credit loss exists, and if so, the amount of an other-than-temporary impairment related to the credit loss is recognized in earnings, while the remaining decline in fair value is recognized in other comprehensive income, net of applicable taxes. Effective April 1, 2018, the available-for-sale No.2016-01, The other-than-temporary impairment losses on available-for-sale were not significant. held-to-maturity Continuous unrealized loss position The following table shows the gross unrealized losses and fair value of available-for-sale held-to-maturity Less than 12 months 12 months or more Total Fair value Gross unrealized losses Fair value Gross unrealized losses Fair value Gross unrealized losses (in millions of yen) March 31, 2019 Available-for-sale Debt securities: Japanese government bonds 2,296,536 1,441 1,332,688 1,557 3,629,224 2,998 Japanese local government bonds 9,752 32 38,873 55 48,625 87 U.S. Treasury bonds and federal agency securities 506,176 231 — — 506,176 231 Other foreign government bonds 438,771 321 26,782 134 465,553 455 Agency mortgage-backed securities (1) 466 2 37,706 591 38,172 593 Residential mortgage-backed securities — — 16,729 191 16,729 191 Commercial mortgage-backed securities 11,256 44 36,760 60 48,016 104 Japanese corporate bonds and other debt securities 417,825 924 440,937 637 858,762 1,561 Foreign corporate bonds and other debt securities 129,164 142 79,716 84 208,880 226 Total 3,809,946 3,137 2,010,191 3,309 5,820,137 6,446 Held-to-maturity Debt securities: Agency mortgage-backed securities (2) — — 469,782 14,423 469,782 14,423 Total — — 469,782 14,423 469,782 14,423 September 30, 2019 Available-for-sale Debt securities: Japanese government bonds 2,634,254 3,208 291,304 1,039 2,925,558 4,247 Japanese local government bonds 40,638 101 32,510 68 73,148 169 U.S. Treasury bonds and federal agency securities 381,789 430 — — 381,789 430 Other foreign government bonds 480,958 292 — — 480,958 292 Agency mortgage-backed securities (1) 1,248 2 10,280 160 11,528 162 Residential mortgage-backed securities 3,221 33 11,000 119 14,221 152 Commercial mortgage-backed securities 12,315 86 17,649 31 29,964 117 Japanese corporate bonds and other debt securities 332,240 945 469,373 786 801,613 1,731 Foreign corporate bonds and other debt securities 173,890 158 5,494 6 179,384 164 Total 4,060,553 5,255 837,610 2,209 4,898,163 7,464 Held-to-maturity Debt securities: Agency mortgage-backed securities (2) — — 412,250 9,767 412,250 9,767 Total — — 412,250 9,767 412,250 9,767 Notes: (1) Agency mortgage-backed securities presented in this line consist of Japanese and Foreign agency mortgage-backed securities, of which the fair values were ¥11,107 million and ¥27,065 million, respectively, at March 31, 2019, and ¥ 11,528 0 9 (2) All Agency mortgage-backed securities presented in this line are Ginnie Mae securities. At September 30, 2019, the MHFG Group did not intend to sell the debt securities in an unrealized loss position and it was not more likely than not that the MHFG Group would be required to sell them before the recovery of their amortized cost bases. For Japanese government bonds, U.S. Treasury bonds and federal agency securities and Agency mortgage-backed securities, their entire amortized cost bases were expected to be recovered since the unrealized losses had not resulted from credit deterioration, but primarily from changes in interest rates. For the debt securities other than those described above, except for the securities for which credit losses have been recognized in income, the MHFG Group determined that their entire amortized cost bases were expected to be recovered, after considering various factors such as the extent to which their fair values were below their amortized cost bases, the external and/or internal ratings and the present values of cash flows expected to be collected. Based on the aforementioned evaluation, except for the securities for which credit losses have been recognized in income, the MHFG Group determined that the debt securities in an unrealized loss position were not considered other-than-temporarily impaired. Realized gains and losses The following table shows the realized gains and losses on sales of available-for-sale Six months ended September 30, 2018 2019 (in millions of yen) Gross realized gains 9,955 36,183 Gross realized losses (8,497 ) (6,167 ) Net realized gains (losses) on sales of available-for-sale 1,458 30,016 Equity securities Equity securities include securities which have readily determinable fair values, securities which qualify for the practical expedient to estimate fair value using the net asset value per share (or its equivalent), and securities which are without readily determinable fair values. Equity securities which have readily determinable fair values mainly consist of common stock of Japanese listed companies. Equity securities without readily determinable fair values include non-marketable Net gains and losses The following table shows the details of the net gains and losses on Equity securities for the six months ended September 30, 2018 and 2019 Six months ended September 30, 2018 2019 (in millions of yen) Net gains (losses) recognized during the period on equity securities 306,788 (126,648 ) Less: Net gains (losses) recognized during the period on equity securities sold during the period 116,308 (3,084 ) Unrealized gains (losses) recognized during the reporting period on equity securities still held at the reporting period 190,480 (123,564 ) Equity securities without readily determinable fair values The following table shows carrying amounts e and cumulative amounts due to downward adjustments and impairments and upward adjustments, at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in millions of yen) Carrying amounts at the end of the period 212,270 227,142 Downward adjustments and impairments 1,413 1,843 Upward adjustments 2,373 8,756 The following table shows amounts recognized in earnings during the period due to downward adjustments and impairments and upward adjustments for e Six months ended September 30, 2018 2019 (in millions of yen) Downward adjustments and impairments 976 430 Upward adjustments 1,837 6,527 The MHFG Group elected to measure all equity securities without readily determinable fair values, which do not qualify for the practical expedient to estimate fair value, using the measurement alternative, which is made on an instrument-by-instrument basis. Under the measurement alternative, equity securities are carried at cost plus or minus changes resulting from observable price changes in orderly transactions for the identical or similar securities of the same issuer. In addition, the MHFG Group assesses whether these equity securities are impaired. Impairment is primarily based on a liquidation value technique that considers the financial condition, credit ratings, and near-term prospects of the issuers. When observable price changes or impairments exist, the securities are adjusted to fair value, with the full difference between the fair value of the security and its carrying amount recognized in earnings. Other investments The following table summarizes the composition of Other investments at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in millions of yen) Equity method investments 354,268 372,006 Investments held by consolidated investment companies 35,472 36,229 Total 389,740 408,235 Equity method investments Investments in investees over which the MHFG Group has the ability to exert significant influence are accounted for using the equity method of accounting. Such investments included marketable equity securities with carrying values of ¥201,034 million and ¥207,210 million, at March 31, 2019 and September 30, 2019, respectively. The aggregate market values of these marketable equity securities were ¥308,137 million and ¥373,477 million, respectively. The majority of the aggregate market values of these marketable equity securities include Orient Corporation, of which the MHFG Group’s proportionate share of the total outstanding common stock was 49.0% as of September 30, 2019. Investments held by consolidated investment companies The MHFG Group consolidates certain investment companies over which it has control through either ownership or other means. Investment companies are subject to specialized industry accounting which requires investments to be carried at fair value, with changes in fair value recorded in earnings. The MHFG Group maintains this specialized industry accounting for investments held by consolidated investment companies, which consist of marketable and non-marketable investments.

Loans

Loans	6 Months Ended
	Sep. 30, 2019
Loans	4. Loans The table below presents loans outstanding by domicile and industry of borrower at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in millions of yen) Domestic: Manufacturing 9,558,146 9,661,265 Construction and real estate 8,954,823 9,193,059 Services 5,113,386 5,486,164 Wholesale and retail 5,163,267 5,292,337 Transportation and communications 3,622,130 3,751,962 Banks and other financial institutions 4,303,231 4,460,760 Government and public institutions 2,358,904 2,186,690 Other industries (Note) 5,477,452 5,581,548 Individuals: Mortgage loans 8,950,216 8,753,545 Other 907,589 869,309 Total domestic 54,409,144 55,236,639 Foreign: Commercial and industrial 19,086,511 18,905,059 Banks and other financial institutions 9,126,392 9,489,618 Government and public institutions 296,872 338,037 Other 33,171 34,376 Total foreign 28,542,946 28,767,090 Total 82,952,090 84,003,729 Less: Unearned income and deferred loan fees - 152,147 147,538 Total loans before allowance for loan losses 82,799,943 83,856,191 Note: Other industries of d Net losses on sales of loans were ¥1,060 million and ¥179 million, including unrealized losses related to recording loans held for sale at the lower of cost or fair value for the six months ended September 30, 2018 and 2019, respectively. The gains and losses on sales of loans are recorded in Other noninterest income and expenses, respectively. Credit quality information In accordance with the MHFG Group’s credit risk management policies, the Group uses an internal rating system that consists of credit ratings for the corporate portfolio segment and pool allocations for the retail portfolio segment as the basis of its risk management infrastructure. Credit ratings consist of obligor ratings which represent the level of credit risk of the obligor, and transaction ratings which represent the ultimate possibility of incurring losses on individual loans by taking into consideration various factors such as collateral or guarantees involved. In principle, obligor ratings are applied to all obligors except those to which pool allocations are applied, and are subject to regular review at least once a year as well as special review which is required whenever the obligor’s credit standing changes. Pool allocations are applied to small loans that are less than a specified amount by pooling customers and loans with similar risk characteristics, and the risk is assessed mainly based on past due status and managed according to such pools. The Group generally reviews the appropriateness and effectiveness of the approach to obligor ratings and pool allocations once a year in accordance with predetermined policies and procedures. The table below presents the MHFG Group’s definition of obligor ratings used by Mizuho Bank, Ltd. (“MHBK”) and Mizuho Trust & Banking Co., Ltd. (“MHTB”): Obligor category (1)(2) Obligor rating (3) Definition Normal A Obligors whose certainty of debt fulfillment is very high, hence their level of credit risk is very low. B Obligors whose certainty of debt fulfillment poses no problems for the foreseeable future, and their level of credit risk is low. C Obligors whose certainty of debt fulfillment and their level of credit risk pose no problems for the foreseeable future. D Obligors whose current certainty of debt fulfillment poses no problems, however, their resistance to future economic environmental changes is low. Watch E1 Obligors that require observation going forward because of either minor concerns regarding their financial position, or their somewhat weak or unstable business conditions. E2 Obligors that require special observation going forward because of problems with their borrowings such as reduced or suspended interest payments, problems with debt fulfillment such as failure to make principal or interest payments, or problems with their financial position as a result of their weak or unstable business conditions. Intensive control F Obligors that are not yet bankrupt but are in financial difficulties and are deemed likely to become bankrupt in the future because of insufficient progress in implementing their management improvement plans or other measures (including obligors that are receiving ongoing support from financial institutions). Substantially bankrupt G Obligors that have not yet become legally or formally bankrupt but are substantially insolvent because they are in serious financial difficulties and are deemed to be incapable of being restructured. Bankrupt H Obligors that have become legally or formally bankrupt. Notes: (1) Special attention obligors are watch obligors with debt in troubled debt restructuring (“TDR”) or 90 days or more delinquent debt. Loans to such obligors are considered impaired. (2) The Group classifies loans to special attention, intensive control, substantially bankrupt and bankrupt obligors as impaired loans. (3) Equivalent obligor ratings are determined for the other portfolio segment. The table below presents credit quality information of loans based on the MHFG Group’s internal rating system at March 31, 2019 and September 30, 2019: Normal obligors Watch obligors excluding special attention obligors (1) Corporate Retail (2) Other (3) Corporate Retail (2) Other (3) Impaired loans Total (in millions of yen) March 31, 2019 Domestic: Manufacturing 9,209,834 69,080 19,805 141,202 8,278 1,303 108,644 9,558,146 Construction and real estate 8,186,308 505,142 15,920 186,753 14,490 25 46,185 8,954,823 Services 4,761,724 165,643 3,281 90,578 18,586 1 73,573 5,113,386 Wholesale and retail 4,686,541 161,392 26,881 127,695 25,553 591 134,614 5,163,267 Transportation and communications 3,472,991 71,934 934 37,593 7,472 — 31,206 3,622,130 Banks and other financial institutions 4,262,125 1,534 72 28,881 319 — 10,300 4,303,231 Government and public institutions 2,358,899 5 — — — — — 2,358,904 Other industries (4) 3,131,072 2,450 2,323,197 7,725 421 3,633 8,954 5,477,452 Individuals 233,986 9,384,955 64,974 21,127 70,427 1,168 81,168 9,857,805 Total domestic 40,303,480 10,362,135 2,455,064 641,554 145,546 6,721 494,644 54,409,144 Foreign: Commercial and industrial 16,061,655 182 2,488,800 347,060 — 38,404 150,410 19,086,511 Banks and other financial institutions 8,623,103 — 492,831 10,458 — — — 9,126,392 Government and public institutions 296,870 — — — — — 2 296,872 Other 1,480 9,713 19,690 333 — 879 1,076 33,171 Total foreign 24,983,108 9,895 3,001,321 357,851 — 39,283 151,488 28,542,946 Total 65,286,588 10,372,030 5,456,385 999,405 145,546 46,004 646,132 82,952,090 September 30, 2019 Domestic: Manufacturing 9,299,310 66,098 14,732 123,362 7,921 542 149,300 9,661,265 Construction and real estate 8,452,801 486,803 11,751 179,437 12,710 — 49,557 9,193,059 Services 5,113,878 160,329 1,883 111,672 17,210 — 81,192 5,486,164 Wholesale and retail 4,839,416 152,789 17,127 123,201 24,216 605 134,983 5,292,337 Transportation and communications 3,608,666 67,073 283 45,291 7,920 — 22,729 3,751,962 Banks and other financial institutions 4,411,489 1,697 276 37,516 334 — 9,448 4,460,760 Government and public institutions 2,186,682 8 — — — — — 2,186,690 Other industries (4) 3,155,810 2,384 2,384,867 12,120 407 10,364 15,596 5,581,548 Individuals 191,099 9,182,326 63,795 36,061 66,080 1,098 82,395 9,622,854 Total domestic 41,259,151 10,119,507 2,494,714 668,660 136,798 12,609 545,200 55,236,639 Foreign: Commercial and industrial 16,104,914 292 2,367,172 317,303 — 33,750 81,628 18,905,059 Banks and other financial institutions 8,838,656 — 638,508 12,454 — — — 9,489,618 Government and public institutions 338,037 — — — — — — 338,037 Other 1,432 9,583 19,316 1,755 — 994 1,296 34,376 Total foreign 25,283,039 9,875 3,024,996 331,512 — 34,744 82,924 28,767,090 Total 66,542,190 10,129,382 5,519,710 1,000,172 136,798 47,353 628,124 84,003,729 Notes: (1) Special attention obligors are watch obligors with debt in TDR or 90 days or more delinquent debt. Loans to such obligors are considered impaired. (2) The primary component of the retail portfolio segment is mortgage loans to individuals which obligor category is classified based on past due status. The trigger to reclassify obligors from normal obligors to watch obligors excluding special attention obligors is when the past due status is more than 30 days. (3) Non-impaired o (4) Other industries of d Impaired loans Loans are considered impaired when, based on current information and events, it is probable that the MHFG Group will be unable to collect all the scheduled payments of principal and interest when due according to the contractual terms of the loans. Factors considered by management in determining if a loan is impaired include delinquency status and the ability of the debtor to make payment of the principal and interest when due. The Group classifies loans to special attention, intensive control, substantially bankrupt and bankrupt obligors as impaired loans. Impaired loans include loans past due for 90 days or more and restructured loans that meet the definition of a TDR in accordance with ASC 310, “Receivables” (“ASC 310”). There are no loans that are ninety days past due and still accruing. The Group does not have any loans to borrowers that cause management to have serious doubts as to the ability of such borrowers to comply with the present loan repayment terms for the periods presented other than those already designated as impaired loans. All of the MHFG Group’s impaired loans are designated as nonaccrual loans and thus interest accruals and the amortization of net origination fees are suspended and capitalized interest is written off. Cash received on nonaccrual loans is accounted for as a reduction of the loan principal if the ultimate collectibility of the principal amount is in doubt, otherwise, as interest income. Loans are not restored to accrual status until interest and principal payments are current and future payments are reasonably assured. Impaired loans are restored to non-impaired non-impaired Recorded investment (1) Requiring an allowance for loan losses Not requiring an allowance for loan losses (2) Total Unpaid principal balance Related allowance (3) Average recorded investment Interest income recognized (4) (in millions of yen) March 31, 2019 Domestic: Manufacturing 103,039 5,605 108,644 111,533 39,301 122,764 1,404 Construction and real estate 36,873 9,312 46,185 51,158 4,661 42,224 487 Services 64,021 9,552 73,573 79,736 16,311 67,679 1,058 Wholesale and retail 124,911 9,703 134,614 147,665 38,763 130,860 1,814 Transportation and communications 28,297 2,909 31,206 32,139 13,146 29,864 412 Banks and other financial institutions 6,473 3,827 10,300 10,300 1,327 10,671 109 Other industries 8,867 87 8,954 9,149 5,761 6,042 29 Individuals 37,488 43,680 81,168 88,331 2,630 86,082 1,326 Total domestic 409,969 84,675 494,644 530,011 121,900 496,186 6,639 Foreign: Total foreign (5) 119,079 32,409 151,488 164,984 47,345 113,559 1,518 Total 529,048 117,084 646,132 694,995 169,245 609,745 8,157 Recorded investment (1) Requiring an allowance for loan losses Not requiring an allowance for loan losses (2) Total Unpaid principal balance Related allowance (3) Average recorded investment Interest income recognized (4) (in millions of yen) September 30, 2019 Domestic: Manufacturing 100,021 49,279 149,300 152,358 35,530 128,972 796 Construction and real estate 39,756 9,801 49,557 56,503 8,491 47,871 279 Services 72,044 9,148 81,192 86,259 16,689 77,383 460 Wholesale and retail 125,938 9,045 134,983 151,913 43,339 134,798 850 Transportation and communications 20,272 2,457 22,729 23,628 6,534 26,968 212 Banks and other financial institutions 5,688 3,760 9,448 9,447 1,001 9,874 51 Other industries 15,323 273 15,596 15,720 6,290 12,275 96 Individuals 40,352 42,043 82,395 87,189 3,317 81,781 584 Total domestic 419,394 125,806 545,200 583,017 121,191 519,922 3,328 Foreign: Total foreign (5) 55,639 27,285 82,924 96,539 31,200 117,206 1,398 Total 475,033 153,091 628,124 679,556 152,391 637,128 4,726 Notes: (1) Amounts represent the outstanding balances of nonaccrual loans. The MHFG Group’s policy for placing loans in nonaccrual status corresponds to the Group’s definition of impaired loans. (2) These impaired loans do not require an allowance for loan losses because the MHFG Group has sufficient collateral to cover probable loan losses. (3) The allowance for loan losses on impaired loans includes the allowance for groups of loans which were collectively evaluated for impairment, in addition to the allowance for those loans that were individually evaluated for impairment. The total carrying amount of the groups of loans which were collectively evaluated for impairment at March 31, 2019 and September 30, 2019 was ¥257,099 million and ¥250,121 million, respectively. (4) Amounts represent the amount of interest income on impaired loans recognized on a cash basis and included in Interest income on loans in the consolidated statements of income. (5) The majority of t c i The remaining balance of impaired loans that have been partially charged off, was ¥25,097 million and ¥20,430 million as of March 31, 2019 and September 30, 2019 respectively. Troubled debt restructurings The MHFG Group considers a loan modification to be a TDR when, for economic or legal reasons related to the obligor’s financial difficulties, it grants a concession to the obligor that it would not otherwise consider. The Group considers the relevant obligor to be in financial difficulty generally when its obligor rating is E2 or below. The following table presents modified loans that were determined to be TDRs during the six months ended September 30, 2018 and 2019: Loan forgiveness or debt to equity swaps Interest rate reduction and/or postponement of principal and/or Recorded investment (1) (in millions of yen) September 30, 2018 Domestic: Manufacturing — — 51,161 Construction and real estate — — 7,764 Services — — 29,203 Wholesale and retail — — 75,593 Transportation and communications — — 13,999 Banks and other financial institutions — — 7,160 Individuals — — 8,866 Total domestic — — 193,746 Foreign: Total foreign (2) 1,008 2,012 9,493 Total 1,008 2,012 203,239 September 30, 2019 Domestic: Manufacturing 689 3,806 57,879 Construction and real estate — — 15,478 Services — — 44,185 Wholesale and retail — — 77,117 Transportation and communications — — 7,916 Banks and other financial institutions — — 7,639 Other industries — — 639 Individuals — — 8,074 Total domestic 689 3,806 218,927 Foreign: Total foreign (2) 470 4,922 38,646 Total 1,159 8,728 257,573 Notes: (1) Amounts represent the book values of loans immediately after the restructurings. (2) The majority of t c i Payment default is deemed to occur when the loan becomes three months past due or the obligor is downgraded to the category of substantially bankrupt or bankrupt. The following table presents payment defaults which occurred during the six months ended September 30, 2018 and 2019 with respect to the loans modified as TDRs within the previous twelve months: Recorded investment September 30, 2018 September 30, 2019 (in millions of yen) Domestic: Manufacturing 383 2,391 Construction and real estate 390 171 Services 714 318 Wholesale and retail 6,700 6,504 Transportation and communications 409 86 Other industries — — Individuals 2,241 884 Total domestic 10,837 10,354 Foreign: Total foreign — 6,436 Total 10,837 16,790 Age analysis of past due loans The table below presents an analysis of the age of the recorded investment in loans that are past due at March 31, 2019 and September 30, 2019: 30-59 days past due 60-89 days past due 90 days or more past due Total past due Current Total (in millions of yen) March 31, 2019 Domestic: Manufacturing 2,210 513 7,036 9,759 9,548,387 9,558,146 Construction and real estate 1,010 1,054 31,092 33,156 8,921,667 8,954,823 Services 633 196 3,494 4,323 5,109,063 5,113,386 Wholesale and retail 1,614 1,415 7,868 10,897 5,152,370 5,163,267 Transportation and communications 363 256 2,119 2,738 3,619,392 3,622,130 Banks and other financial institutions 3 484 6 493 4,302,738 4,303,231 Government and public institutions — — — — 2,358,904 2,358,904 Other industries 2 — 57 59 5,477,393 5,477,452 Individuals 27,139 11,013 28,965 67,117 9,790,688 9,857,805 Total domestic 32,974 14,931 80,637 128,542 54,280,602 54,409,144 Foreign: Total foreign (Note) 668 211 26,316 27,195 28,515,751 28,542,946 Total 33,642 15,142 106,953 155,737 82,796,353 82,952,090 September 30, 2019 Domestic: Manufacturing 733 983 7,601 9,317 9,651,948 9,661,265 Construction and real estate 834 849 28,678 30,361 9,162,698 9,193,059 Services 390 2,986 5,171 8,547 5,477,617 5,486,164 Wholesale and retail 2,317 1,226 11,460 15,003 5,277,334 5,292,337 Transportation and communications 106 366 2,154 2,626 3,749,336 3,751,962 Banks and other financial institutions 116 — 41 157 4,460,603 4,460,760 Government and public institutions — — — — 2,186,690 2,186,690 Other industries — — 221 221 5,581,327 5,581,548 Individuals 22,918 26,303 32,367 81,588 9,541,266 9,622,854 Total domestic 27,414 32,713 87,693 147,820 55,088,819 55,236,639 Foreign: Total foreign (Note) 1,181 249 25,936 27,366 28,739,724 28,767,090 Total 28,595 32,962 113,629 175,186 83,828,543 84,003,729 Note: The majority of t c i Loans held for sale Loans that have been identified for sale are classified as loans held for sale within Other assets and are accounted for at the lower of cost or fair value. The outstanding balance of loans held for sale was ¥24,921 million and ¥68,569 million at March 31, 2019 and September 30, 2019, respectively .

Allowance for loan losses

Allowance for loan losses	6 Months Ended
	Sep. 30, 2019
Allowance for loan losses	5. Allowance for loan losses The MHFG Group maintains an appropriate allowance for loan losses to absorb probable losses inherent in the loan portfolio and makes adjustments to such allowance through Provision (credit) for loan losses in the consolidated statements of income. Loan principal that management judges to be uncollectible, based on detailed loan reviews and a credit quality assessment, is charged off against the allowance for loan losses. In general, the MHFG Group charges off loans when the Group determines that the obligor should be classified as substantially bankrupt or bankrupt. See Note 4 “Loans” for the definitions of obligor categories. Obligors in the retail portfolio segment are generally determined to be substantially bankrupt when they are past due for more than six months, and as for obligors in the corporate and other portfolio segments, the Group separately monitors the credit quality of each obligor without using time-based triggers. Subsequent recoveries of previously charged-off The allowance for loan losses is determined in accordance with ASC 310 and ASC 450, “Contingencies” (“ASC 450”). The MHFG Group measures the impairment of a loan when it is probable that the Group will be unable to collect all amounts due according to the contractual terms of the loan agreement, based on (1) the present value of expected future cash flows, after considering the restructuring effect and subsequent payment default with respect to TDRs, discounted at the loan’s initial effective interest rate, or (2) the loan’s observable market price, or (3) the fair value of the collateral if the loan is collateral dependent. The collateral that the Group obtains for loans consists primarily of real estate. In obtaining the collateral, the Group evaluates the fair value of the collateral and its legal enforceability. The Group also performs subsequent re-evaluations At MHBK and MHTB, when management estimates probable credit losses to determine the allowance for loan losses, small balance, homogeneous loans are classified in the retail portfolio segment, and loans other than these are classified in the corporate portfolio segment. The corporate portfolio segment consists of loans originated by MHBK and MHTB, and includes mainly business loans such as those used for working capital and capital expenditure, as well as loans for which the primary source of repayment of the obligation is income generated by the relevant assets such as project finance, asset finance and real estate finance. The retail portfolio segment consists mainly of residential mortgage loans, originated by MHBK. The other portfolio segment consists of loans of subsidiaries other than MHBK and MHTB, such as consolidated VIEs and overseas subsidiaries. For the corporate portfolio segment, the credit quality review process and the credit rating process serve as the basis for determining the allowance for loan losses. Through such processes loans are categorized into groups to reflect the probability of default, whereby the MHFG Group’s management assesses the ability of borrowers to service their debt, taking into consideration current financial information, ability to generate cash, historical payment experience, analysis of relevant industry segments and current trends. For the retail portfolio segment, the different categories of past due status of loans are primarily utilized in the credit quality review and the credit rating processes as the basis for determining the allowance for loan losses. MHFG Group’s accounting policies and the methodology used to estimate the allowance for loan losses for the other portfolio segment are equivalent to the policies and methodology used for the corporate portfolio segment. The formula allowance is applied to groups of loans that are collectively evaluated for impairment. The evaluation of the inherent loss in respect of these loans involves a high degree of uncertainty, subjectivity and The historical loss rate is adjusted, where appropriate, to reflect current factors, such as general economic and business conditions affecting the key lending areas of the MHFG Group, credit quality trends, specific industry conditions by portfolio segments, and recent loss experience in particular segments of the portfolio. When determining the length of the period to calculate the probability of default, the Group considers the uncertainty in the economic and business conditions. The estimation of the formula allowance is analyzed on a periodic basis by comparing the allowance with the actual results subsequent to the balance sheet date. Changes in Allowance for loan losses by portfolio segment for the six months ended September 30, 2018 and 2019 are shown below: Corporate Retail Other Total (in millions of yen) Six months ended September 30, 2018 Balance at beginning of period 249,072 28,192 32,638 309,902 Provision (credit) for loan losses (13,435 ) (2,290 ) 2,445 (13,280 ) Charge-offs (27,419 ) (1,243 ) (2,602 ) (31,264 ) Recoveries 4,914 220 2,409 7,543 Net charge-offs (22,505 ) (1,023 ) (193 ) (23,721 ) Others (Note) 2,519 — (931 ) 1,588 Balance at end of period 215,651 24,879 33,959 274,489 Six months ended September 30, 2019 Balance at beginning of period 252,903 23,230 31,068 307,201 Provision (credit) for loan losses 17,275 (805 ) (2,697 ) 13,773 Charge-offs (24,288 ) (1,397 ) (3,349 ) (29,034 ) Recoveries 2,724 309 1,021 4,054 Net charge-offs (21,564 ) (1,088 ) (2,328 ) (24,980 ) Others (Note) (3,887 ) — (685 ) (4,572 ) Balance at end of period 244,727 21,337 25,358 291,422 Note: Others includes primarily foreign exchange translation. The table below presents Allowance for loan losses and loans outstanding by portfolio segment disaggregated on the basis of impairment method at March 31, 2019 and September 30, 2019: Corporate Retail Other Total (in millions of yen) March 31, 2019 Allowance for loan losses 252,903 23,230 31,068 307,201 of which individually evaluated for impairment 139,472 2,122 8,933 150,527 of which collectively evaluated for impairment 113,431 21,108 22,135 156,674 Loans (Note) 66,804,088 10,596,994 5,551,008 82,952,090 of which individually evaluated for impairment 539,893 20,886 54,319 615,098 of which collectively evaluated for impairment 66,264,195 10,576,108 5,496,689 82,336,992 September 30, 2019 Allowance for loan losses 244,727 21,337 25,358 291,422 of which individually evaluated for impairment 124,693 1,884 5,338 131,915 of which collectively evaluated for impairment 120,034 19,453 20,020 159,507 Loans (Note) 68,067,130 10,343,150 5,593,449 84,003,729 of which individually evaluated for impairment 547,792 20,099 35,617 603,508 of which collectively evaluated for impairment 67,519,338 10,323,051 5,557,832 83,400,221 Note: Amounts represent loan balances before deducting unearned income and deferred loan fees.

Other assets and liabilities

Other assets and liabilities	6 Months Ended
	Sep. 30, 2019
Other assets and liabilities	6. Other assets and liabilities The following table sets forth the details of other assets and liabilities at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in millions of yen) Other assets: Accounts receivable: Receivables from brokers, dealers and customers for securities transactions (1) 1,517,235 1,348,181 Other 400,676 358,547 Collateral pledged: Collateral pledged for derivative transactions 856,439 1,008,596 Margins provided for futures contracts 159,747 269,143 Other 857,814 865,875 Prepaid pension cost 850,472 860,365 ROU assets (2) — 647,185 Security deposits 123,317 108,293 Loans held for sale 24,921 68,569 Other 485,383 473,301 Total 5,276,004 6,008,055 Other liabilities: Accounts payable: Payables to brokers, dealers and customers for securities transactions (1) 2,572,315 2,042,447 Other 442,776 451,208 Guaranteed trust principal ( 3 809,450 813,761 Lease Liabilities (2) — 656,409 Collateral accepted: Collateral accepted for derivative transactions 589,411 533,308 Margins accepted for futures contracts 339,863 541,070 Unearned income ( 4 126,594 120,908 Other 1,052,297 1,024,549 Total 5,932,706 6,183,660 Notes: (1) Receivables from brokers, dealers and customers for securities transactions included ¥555,938 million and ¥181,535 million of such receivables of consolidated VIEs at March 31, 2019 and September 30, 2019, respectively. Payables to brokers, dealers and customers for securities transactions included ¥620,766 million and ¥172,473 million of such payables of consolidated VIEs at March 31, 2019 and September 30, 2019, respectively. (2) ROU assets and lease liabilities were recognized in connection with the adoption of ASU No.2016-02 on April 1, 2019. See Note 1 “Basis of presentation” and Note 2 “Recently issued accounting pronouncements” for further information. ( 3 Guaranteed trust principal is the liability of certain consolidated trust arrangements that meet the definition of a VIE for which the MHFG Group provides guarantees for the repayment of principal. See Note 15 “Variable interest entities and securitizations” for further discussion of the guaranteed principal money trusts. (4) Unearned income is primarily comprised of loan fees received from consumer loan customers when loans are made. This income is being deferred and recognized in earnings over the life of the loan.

Preferred and common stock

Preferred and common stock	6 Months Ended
	Sep. 30, 2019
Preferred and common stock	7. Preferred and common stock Preferred stock The composition of preferred stock at March 31, 2019 and September 30, 2019 is as follows: Class of stock March 31, 2019 September 30, 2019 Authorized Issued Authorized Issued (number of shares) Class XIV preferred stock 900,000,000 — 900,000,000 — Class XV preferred stock 900,000,000 — 900,000,000 — Class XVI preferred stock 1,500,000,000 — 1,500,000,000 — Common stock The following table shows the changes in the number of issued shares of common stock during the fiscal year ended March 31, 2019 and the six months ended September 30, 2019: March 31, 2019 September 30, 2019 (number of shares) Balance at beginning of period 25,389,644,945 25,392,498,945 Issuance of new shares of common stock due to exercise of stock acquisition rights 2,854,000 — Balance at end of period 25,392,498,945 25,392,498,945

Accumulated other comprehensive

Accumulated other comprehensive income, net of tax	6 Months Ended
	Sep. 30, 2019
Accumulated other comprehensive income, net of tax	8. Accumulated other comprehensive income, net of tax Changes in each component of AOCI for the six months ended September 30, 2018 and 2019 are as follows: Six months ended September 30, 2018 2019 (in millions of yen) AOCI, balance at beginning of period, previously reported 1,741,894 164,021 Cumulative effect of change in accounting principles (1) (1,535,142 ) (1,052 ) AOCI, balance at beginning of period, adjusted 206,752 162,969 Net unrealized gains (losses) on available-for-sale Balance at beginning of period, previously reported 1,556,585 22,019 Cumulative effect of change in accounting principles (1) (1,525,064 ) — Balance at beginning of period, adjusted 31,521 22,019 Unrealized holding gains (losses) during period (25,155 ) 25,843 Less: reclassification adjustments for losses (gains) included in net income (862 ) (20,824 ) Change during period (26,017 ) 5,019 Balance at end of period 5,504 27,038 Foreign currency translation adjustments: Balance at beginning of period, previously reported (35,076 ) (58,558 ) Cumulative effect of change in accounting principles (1) — (1,052 ) Balance at beginning of period, adjusted (35,076 ) (59,610 ) Foreign currency translation adjustments during period 7,678 (63,466 ) Less: reclassification adjustments for losses (gains) included in net income — — Change during period 7,678 (63,466 ) Balance at end of period (27,398 ) (123,076 ) Pension liability adjustments: Balance at beginning of period 220,385 196,446 Unrealized gains (losses) during period (218 ) (1,720 ) Less: reclassification adjustments for losses (gains) included in net income (2,916 ) (2,130 ) Change during period (3,134 ) (3,850 ) Balance at end of period 217,251 192,596 Own credit risk adjustments (2) : Balance at beginning of period, previously reported — 4,114 Cumulative effect of change in accounting principles (1) (10,078 ) — Balance at beginning of period, adjusted (10,078 ) 4,114 Unrealized gains (losses) during period 2,656 7,320 Less: reclassification adjustments for losses (gains) included in net income (20 ) (1,277 ) Change during period 2,636 6,043 Balance at end of period (7,442 ) 10,157 Total other comprehensive income (loss), net of tax attributable to MHFG shareholders (18,837 ) (56,254 ) AOCI, balance at end of period 187,915 106,715 Notes: (1) See Note 2 “Recently issued accounting pronouncements” for further details of the cumulative-effect adjustment for AOCI. (2) The MHFG Group adopted ASU No.2016-01 The following table shows the amounts reclassified out of AOCI into net income during the six months ended September 30, 2019: Six months ended September 30, 2019 Before tax (1) Tax effect (2) Net of tax before allocation to noncontrolling interests Net of tax attributable to noncontrolling interests (2) Net of tax attributable to MHFG shareholders (in millions of yen) Amounts reclassified out of AOCI into net income: Affected line items in the consolidated statements of income: Net unrealized gains (losses) on available-for-sale 30,013 (9,192 ) 20,821 3 20,824 Investment gains (losses)—net Pension liability adjustments 3,155 (937 ) 2,218 (88 ) 2,130 Salaries and employee benefits Own credit risk adjustments 1,921 (588 ) 1,333 (56 ) 1,277 Other noninterest income (expenses) Total 35,089 (10,717 ) 24,372 (141 ) 24,231 Notes: (1) The financial statement line item in which the amounts in the Before tax column are reported in the Consolidated statements of income is listed to the right of the table. (2) The financial statement line items in which the amounts in the Tax effect and the Net of tax attributable to noncontrolling interest columns are reported in the consolidated statements of income are Income tax expense and Net income, respectively.

Regulatory matters

Regulatory matters	6 Months Ended
	Sep. 30, 2019
Regulatory matters	9. Regulatory matters Regulatory capital requirements MHFG, MHBK, and MHTB are subject to regulatory capital requirements administered by the Financial Services Agency in accordance with the provisions of Japan’s Banking Act and related regulations. Certain foreign banking subsidiaries are subject to regulation and control by local supervisory authorities, including central banks. Capital adequacy ratios and leverage ratios of MHFG, MHBK, and MHTB as of March 31, 2019 and September 30, 2019 calculated in accordance with Japanese GAAP and the guidelines established by the Financial Services Agency are set forth in the following table: March 31, 2019 September 30, 2019 Amount Ratio Amount Ratio (in billions of yen, except percentages) Consolidated: MHFG: Common Equity Tier 1 capital: Required (Note) 4,661 8.05 4,878 8.05 Actual 7,390 12.76 7,383 12.18 Tier 1 capital: Required (Note) 5,529 9.55 5,787 9.55 Actual 9,232 15.94 9,162 15.11 Total risk-based capital: Required (Note) 6,687 11.55 6,999 11.55 Actual 10,918 18.85 10,865 17.92 Leverage Ratio: Required 6,257 3.00 6,327 3.00 Actual 9,232 4.42 9,162 4.34 MHBK: Common Equity Tier 1 capital: Required 2,388 4.50 2,497 4.50 Actual 6,690 12.60 6,761 12.18 Tier 1 capital: Required 3,184 6.00 3,329 6.00 Actual 8,527 16.06 8,533 15.37 Total risk-based capital: Required 4,246 8.00 4,439 8.00 Actual 10,098 19.02 10,142 18.27 Leverage Ratio: Required 5,758 3.00 5,815 3.00 Actual 8,527 4.44 8,533 4.40 MHTB: Common Equity Tier 1 capital: Required 95 4.50 96 4.50 Actual 500 23.67 510 23.96 Tier 1 capital: Required 127 6.00 128 6.00 Actual 501 23.70 511 23.99 Total risk-based capital: Required 169 8.00 170 8.00 Actual 505 23.87 513 24.11 Leverage Ratio: Required 229 3.00 222 3.00 Actual 501 6.55 511 6.90 Non-consolidated: MHBK: Common Equity Tier 1 capital: Required 2,272 4.50 2,350 4.50 Actual 6,363 12.60 6,423 12.30 Tier 1 capital: Required 3,029 6.00 3,133 6.00 Actual 8,199 16.23 8,191 15.68 Total risk-based capital: Required 4,039 8.00 4,177 8.00 Actual 9,757 19.32 9,792 18.75 Leverage Ratio: Required 5,517 3.00 5,556 3.00 Actual 8,199 4.45 8,191 4.42 MHTB: Common Equity Tier 1 capital: Required 94 4.50 95 4.50 Actual 494 23.58 500 23.64 Tier 1 capital: Required 126 6.00 127 6.00 Actual 494 23.58 500 23.64 Total risk-based capital: Required 168 8.00 169 8.00 Actual 498 23.75 503 23.76 Leverage Ratio: Required 227 3.00 220 3.00 Actual 494 6.53 500 6.82 Note: The required ratios disclosed above, at March 31, 2019 and September 30, 2019, include the transitional capital conservation buffer of 2.5%, the countercyclical capital buffer of 0.05%, and the transitional additional loss absorbency requirements for global systemically important banks (“G-SIBs”) (“D-SIBs”) MHFG’s securities subsidiary in Japan is also subject to the capital adequacy requirement under Japan’s Financial Instruments and Exchange Act. Failure to maintain a minimum capital ratio will trigger mandatory regulatory actions. Management believes, as of each latest balance sheet date, that MHFG, MHBK, MHTB, and their securities subsidiary in Japan and foreign banking subsidiaries were in compliance with all capital adequacy requirements to which they were subject.

Earnings per common share

Earnings per common share	6 Months Ended
	Sep. 30, 2019
Earnings per common share	10. Earnings per common share Basic earnings per common share are computed by dividing net income attributable to MHFG common shareholders by the weighted average number of common shares outstanding during the period. Diluted earnings per common share reflect all dilutive potential common shares such as stock options. The following table sets forth the computation of basic and diluted earnings per common share for the six months ended September 30, 2018 and 2019: Six months ended September 30, 2018 2019 (in millions of yen) Net income: Net income attributable to MHFG common shareholders 285,270 212,984 Effect of dilutive securities — — Net income attributable to common shareholders after assumed conversions 285,270 212,984 Six months ended September 30, 2018 2019 (thousands of shares) Shares: Weighted average common shares outstanding 25,363,167 25,367,997 Effect of dilutive securities: Stock options and the common shares of MHFG under the stock compensation programs 4,790 2,093 Weighted average common shares after assumed conversions 25,367,957 25,370,090 Six months ended September 30, 2018 2019 (in yen) Earnings per common share: Basic net income per common share 11.25 8.40 Diluted net income per common share 11.25 8.40

Income taxes

Income taxes	6 Months Ended
	Sep. 30, 2019
Income taxes	11. Income taxes The following table presents the components of Income tax expense for the six months ended September 30, 2018 and 2019: Six months ended 2018 2019 (in millions of yen) Current tax expense 114,666 88,437 Deferred tax expense (benefit) (28,961 ) (5,317 ) Total income tax expense 85,705 83,120 The preceding table does not reflect the tax effects of items recorded directly in Equity for the six months ended September 30, 2018 and 2019. The detailed amounts recorded directly in Equity are as follows: Six months ended 2018 2019 (in millions of yen) Net unrealized gains (losses) on available-for-sale Unrealized gains (losses) (11,292 ) 11,023 Less: reclassification adjustments (383 ) (9,192 ) Total (11,675 ) 1,831 Pension liability adjustments: Unrealized gains (losses) (97 ) (643 ) Less: reclassification adjustments (1,184 ) (937 ) Total (1,281 ) (1,580 ) Own credit risk adjustments: Unrealized gains (losses) 967 (43 ) Less: reclassification adjustments (9 ) (588 ) Total 958 (631 ) Total tax effect before allocation to noncontrolling interests (11,998 ) (380 ) The statutory tax rates were both The difference of the tax rates for the six months ended September 30, 2019 was immaterial. At September 30, 2019, the MHFG Group had net operating loss carryforwards totaling ¥647 billion. The total amount of unrecognized tax benefits was ¥3,098 million at September 30, 2019, which would, if recognized, affect the Group’s effective tax rate. The Group classifies interest and penalties accrued relating to unrecognized tax benefits as Income tax expense. Approximately ¥9 billion of unrecognized tax benefits at March 31, 2019 was resolved in the six months period ended September 30, 2019 due to the close of a tax The amount of additional unrecognized tax benefits for the period related to the tax positions taken was immaterial. The MHFG Group does not anticipate that increases or decreases of unrecognized tax benefits within the next twelve months would have a material effect on its consolidated results of operations or financial condition.

Pension and other employee bene

Pension and other employee benefit plans	6 Months Ended
	Sep. 30, 2019
Pension and other employee benefit plans	12. Pension and other employee benefit plans The following table summarizes the components of net periodic benefit cost of the severance indemnities and pension plans of the MHFG Group for the six months ended September 30, 2018 and 2019: Six months ended September 30, 2018 2019 (in millions of yen) Service cost-benefits earned during the period 21,726 22,729 Interest costs on projected benefit obligations 3,331 2,666 Expected return on plan assets (19,124 ) (20,158 ) Amortization of prior service benefits 76 19 Amortization of net actuarial loss (gain) (3,942 ) (3,064 ) Special termination benefits 1,792 2,188 Net periodic benefit cost 3,859 4,380 As previously disclosed in the consolidated financial statements for the fiscal year ended March 31, 2019, the total contribution of approximately ¥52 billion is expected to be paid to the pension plans during the fiscal year ending March 31, 2020. For the six months ended September 30, 2019, the total contribution of ¥26 billion has been paid to the pension plans. The additional contribution of ¥26 billion is expected to be paid during the remainder of the fiscal year ending March 31, 2020.

Derivative financial instrument

Derivative financial instruments	6 Months Ended
	Sep. 30, 2019
Derivative financial instruments	13. Derivative financial instruments The MHFG Group enters into derivative financial instruments in response to the diverse needs of customers, to control the risk related to the assets and liabilities of the MHFG Group, as part of its asset and liability management, and for proprietary trading purposes. The MHFG Group is exposed primarily to market risk associated with interest rate, commodity, foreign currency, and equity products. Market risk arises from changes in market prices or indices, interest rates and foreign exchange rates that may result in an adverse change in the market value of the financial instrument or an increase in its funding costs. Exposure to market risk is managed by imposing position limits and monitoring procedures and by initiating hedging transactions. In addition to market risk, the MHFG Group is exposed to credit risk associated with counterparty default or nonperformance in respect of transactions. Counterparty credit risk arises when a counterparty fails to perform according to the terms and conditions of the contract and the value of the underlying collateral held, if applicable, is not sufficient to recover resulting losses. The exposure to counterparty credit risk is measured by the fair value of all derivatives and its potential exposure at the balance sheet dates. The exposure to counterparty credit risk is managed by entering into legally enforceable master netting agreements to mitigate the overall counterparty credit risk, requiring underlying collateral and guarantees based on an individual credit analysis of each obligor and evaluating the credit features of each instrument. In addition, credit approvals, limits and monitoring procedures are also imposed. Notional and fair value amounts of derivative instruments The following table summarizes the notional and fair value amounts of derivative instruments outstanding as of March 31, 2019 and September 30, 2019. The fair values of derivatives are presented on a gross basis, derivative receivables and payables are not offset. In addition, they are not offset against the amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral under master netting agreements in the consolidated balance sheets, or the table below. Fair value Derivative receivables (2) Derivative payables (2) March 31, 2019 Notional amount (1) Designated as hedges Not designated as hedges Designated as hedges Not designated as hedges (in billions of yen) Interest rate contracts 1,052,267 — 5,786 — 5,610 Foreign exchange contracts 166,383 — 1,959 — 1,758 Equity-related contracts 5,181 — 125 — 142 Credit-related contracts 2,939 — 18 — 17 Other contracts 438 — 16 — 14 Total 1,227,208 — 7,904 — 7,541 Fair value Derivative receivables (2) Derivative payables (2) September 30, 2019 Notional amount (1) Designated as hedges Not designated as hedges Designated as hedges Not designated as hedges (in billions of yen) Interest rate contracts 1,102,120 — 7,054 — 6,788 Foreign exchange contracts 170,816 — 2,342 — 2,202 Equity-related contracts 6,197 — 148 — 176 Credit-related contracts 2,923 — 21 — 25 Other contracts 425 — 16 — 15 Total 1,282,481 — 9,581 — 9,206 Notes: (1) Notional amount includes the sum of gross long and gross short third-party contracts. (2) Derivative receivables and payables are recorded in Trading account assets and Trading account liabilities, respectively. The MHFG Group provided and/or accepted cash collateral for derivative transactions under master netting agreements. The cash collateral, which was not offset against derivative positions, was included in Other assets and Other liabilities, respectively, of which the amounts were ¥856 billion and ¥ 589 1,009 533 Hedging activities In order to qualify for hedge accounting, a derivative must be considered highly effective at reducing the risk associated with the exposure being hedged. Each derivative must be designated as a hedge, with documentation of the risk management objective and strategy, including identification of the hedging instrument, the hedged item and the risk exposure, and how effectiveness is to be assessed prospectively and retrospectively. The extent to which a hedging instrument is effective at achieving offsetting changes in fair value or cash flows must be assessed at least quarterly. The MHFG Group’s hedging activities include fair value and net investment hedges. Fair value hedges The MHFG Group primarily uses forward contracts to modify exposure to changes in the fair value of Equity securities. The Group adopted ASU No.2016-01 Before the adoption of the ASU, for qualifying fair value hedges, all changes in the fair value of the derivative and the corresponding hedged item relating to the risk being hedged were recognized in earnings in Investment gains (losses)—net. The change in fair value of the portion of the hedging instruments excluded from the assessment of hedge effectiveness was recorded in Trading account gains (losses)—net. No ineffectiveness existed because the MHFG Group chose to exclude changes in the differences between the spot and the forward prices from the effectiveness test. If the hedge relationship was terminated, the fair value adjustment to the hedged item continued to be reported as part of the basis of the item. The fair value adjustment was recognized in earnings upon the sale of the hedged item. Net investment hedges The MHFG Group uses forward foreign exchange contracts and foreign currency-denominated debt instruments to protect the value of net investments in non-Japanese entire The following table summarizes gains and losses information related to net investment hedges for the six months ended September 30, 2018 and 2019: Gains (losses) recorded in other for six months ended September 30, 2018 2019 (in millions of yen) Financial instruments hedging foreign exchange risk 1,906 (1,044 ) Total 1,906 (1,044 ) Note: Related to the net investment hedges, gains (losses) of ¥ 186 million and ¥( 260 m illion were reclassified from Accumulated other comprehensive income to earnings for the six months ended September 30, 2018 and Derivative instruments not designated or qualifying as hedges The MHFG Group enters into the following derivative transactions that do not qualify for hedge accounting with a view to implementing risk management strategies: (1) interest-rate swap transactions for the purpose of economically managing the interest-rate risks in deposits, loans etc., (2) currency swap transactions for the purpose of economically managing the foreign exchange risk of these assets, and (3) credit derivatives for the purpose of economically managing the credit risk in loans, residential mortgage-backed securities (“RMBS”), commercial mortgage-backed securities (“CMBS”), collateralized loan obligations (“CLO”) and other similar assets. Such derivatives are accounted for as trading positions. The changes in fair value of these instruments are primarily recorded in Trading account gains (losses) - s es The following table summarizes gains and losses on derivatives not designated or qualifying as hedges during the six months ended September 30, 2018 and 2019: Gains (losses) recorded in income 2018 2019 (in millions of yen) Interest rate contracts (75,324 ) 210,909 Foreign exchange contracts 26,706 (30,736 ) Equity-related contracts 20,432 (494 ) Credit-related contracts ( 1 (35 ) (3,546 ) Other contracts (785 ) (1,650 ) Total (29,006 ) 174,483 Notes: (1) Amounts include the net gains (losses) of ¥( 215 ( 426 ) Credit derivatives A credit derivative is a bilateral contract between a seller and a buyer of protection against the credit risk of a particular entity. Credit derivatives generally require that the seller of credit protection make payments to the buyer upon the occurrence of predefined credit events, which include bankruptcy, dissolution or insolvency of the referenced entity. The MHFG Group either purchases or writes protection on either a single name or a portfolio of reference credits. The Group enters into credit derivatives to help mitigate credit risk in its corporate loan portfolio and other cash positions, to take proprietary trading positions, and to facilitate client transactions. The notional amount of credit derivatives represents the maximum potential amount of future payments the seller could be required to make. If the predefined credit event occurs, the seller will generally have a right to collect on the underlying reference credit and the related cash flows, while being liable for the full notional amount of credit protection to the buyer. The Group manages credit risk associated with written protection by purchasing protection with identical or similar underlying reference credits, which substantially offsets its exposure. Thus, the notional amount is not necessarily a reliable indicator of the Group’s actual loss exposure. The following table summarizes the notional and fair value amounts of credit derivatives at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 Notional amount Fair value Notional amount Fair value (in billions of yen) Credit protection written: Investment grade 1,266 12 1,072 13 Non-investment 199 3 225 5 Total 1,465 15 1,297 18 Credit protection purchased 1,628 (14 ) 1,788 (22 ) Note: The rating scale is based upon either the external ratings or the internal ratings of the underlying reference credit. The lowest investment grade rating is considered to be BBB - non-investment Non-investment The following table shows the maximum potential amount of future payments for credit protection written by expiration period at March 31, 2019 and September 30, 2019: Maximum payout/Notional amount March 31, 2019 September 30, 2019 (in billions of yen) One year or less 326 293 After one year through five years 1,057 902 After five years 82 102 Total 1,465 1,297 Note: The maximum potential amount of future payments is the aggregate notional amount of the credit derivatives where the Group wrote the credit protection, and it has not been reduced by the effect of any amounts that the Group may possibly collect on the underlying assets and the related cash flows, nor netted against that of credit protection purchased. Credit-related contingent features Certain of the MHFG Group’s derivative instruments contain provisions that require the Group’s debt to maintain an investment grade credit rating from the major credit rating agencies. If the Group’s debt credit rating were to fall below investment grade, the counterparties to the derivative instruments could request immediate payment or demand immediate and ongoing full overnight collateralization on derivative instruments which are in net liability positions for the Group. The following table shows the quantitative information about derivative instruments with credit-risk-related contingent features at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in billions of yen) Aggregate fair value of derivative instruments with credit-risk-related contingent features in net liability positions 511 695 Collateral provided to counterparties in the normal course of business 489 679 Amount required to be posted as collateral or settled immediately if credit-risk-related contingent features were triggered 22 16

Commitments and contingencies

Commitments and contingencies	6 Months Ended
	Sep. 30, 2019
Commitments and contingencies	14. Commitments and contingencies Obligations under guarantees The MHFG Group provides guarantees or indemnifications to counterparties to enhance their credit standing and enable them to complete a variety of business transactions. A guarantee represents an obligation to make payments to third parties if the counterparty fails to fulfill its obligation under a borrowing arrangement or other contractual obligation. The Group records all guarantees and similar obligations subject to ASC 460, “Guarantees” (“ASC 460”) at fair value in the consolidated balance sheets at the inception of the guarantee. The table below summarizes the maximum potential amount of future payments by type of guarantee at March 31, 2019 and September 30, 2019. The maximum potential amount of future payments disclosed below represents the contractual amounts that could be required to be repaid in the event of the guarantees being executed, without consideration of possible recoveries under recourse provisions or from collateral held. With respect to written options included in derivative financial instruments in the table below, in theory, the MHFG Group is exposed to unlimited losses; therefore, the table shows the notional amounts of the contracts as a substitute for the maximum exposure. March 31, 2019 September 30, 2019 (in billions of yen) Performance guarantees 2,307 2,182 Guarantees on loans 289 246 Guarantees on securities 145 110 Other guarantees 2,324 2,291 Guarantees for the repayment of trust principal 65 63 Liabilities of trust accounts 362 376 Derivative financial instruments 14,170 19,421 The table below presents the maximum potential amount of future payments of performance guarantees, guarantees on loans, guarantees on securities and other guarantees classified based on internal ratings at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in billions of yen) Investment grade 4,124 3,909 Non-investment 941 920 Total 5,065 4,829 Note: Investment grade in the internal rating scale generally corresponds to BBB- Other off-balance-sheet In addition to guarantees, the MHFG Group issues other off-balance-sheet The table below summarizes the contractual amounts with regard to these undrawn commitments at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in billions of yen) Commitments to extend credit (Note) 76,857 78,075 Commercial letters of credit 778 818 Total 77,635 78,893 Note: Commitments to extend credit include commitments to invest in securities. Legal proceedings The MHFG Group is involved in normal collection proceedings initiated by the Group and other legal proceedings in the ordinary course of business. In accordance with ASC 450 “Contingencies” (“ASC 450”), the Group recognizes a liability for loss contingencies arising from such proceedings when a loss is probable and the loss amount or the range of the loss can be reasonably estimated. If a loss does not meet this condition but is reasonably possible, the Group does not recognize a liability but discloses the detail of such proceedings. Based on the information available as of the date of the consolidated financial statements, the Group believes that the outcome of the collection and legal proceedings will not have a significant adverse effect on the consolidated financial statements. Leases The MHFG Group is obligated under a number of lease arrangements. The Group’s lessee arrangements mainly consist of operating leases for real estate, such as office space , including its head office, and branches . Finance leases are not significant. Some of the Group’s operating leases include variable lease payments. The following table presents the consolidated balance sheet information related to operating leases as of September 30, 2019: As of September 30, 2019 (in millions of yen, except for ROU assets (Note) 647,185 Lease liabilities (Note) 656,409 Weighted average: Remaining lease term 15.8years Discount rate 0.55% Note: ROU assets and lease liabilities are included in Other assets and Other liabilities, respectively, on the consolidated balance sheet s The following table presents lease cost and supplemental information related to operating leases for the six months ended September 30, 2019: Six months ended September 30, (in millions of yen) Lease cost (Note) 62,003 ROU assets obtained in exchange for new lease liabilities 45,904 Operating cash flows 51,120 Note: Lease cost for operating leases are included in Occupancy expenses on the consolidated statement s The Group’s variable lease costs and costs for leases with terms of twelve months or less are not significant. The following table shows future lease payments under operating leases as of September 30, 2019: As of September 30, 2019 (in millions of yen) Fiscal year ending March 31: 2020 (excluding six months ended September 30, 2019) 49,182 2021 84,578 2022 64,138 2023 52,167 2024 46,829 2025 and thereafter 386,291 Total lease payments 683,185 Amount representing interest 26,776 Total lease liabilities for operating leases 656,409

Variable interest entities and

Variable interest entities and securitizations	6 Months Ended
	Sep. 30, 2019
Variable interest entities and securitizations	15. Variable interest entities and securitizations Variable interest entities In the normal course of business, the MHFG Group is involved with VIEs primarily through the following types of transactions: asset-backed commercial paper/loan programs, asset-backed securitizations, investments in securitization products, investment funds, trust arrangements, structured finance, and funding vehicles. The Group consolidates certain of these VIEs, where the Group is deemed to be the primary beneficiary because it has both (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The MHFG Group reassesses whether it is the primary beneficiary on an ongoing basis as long as the Group has any continuing involvement with the VIE. There are also other VIEs, where the Group has determined that it is not the primary beneficiary but has significant variable interests. In evaluating the significance of the variable interests, the Group takes into consideration the extent of its involvement with each VIE, such as the seniority of its investments, the share of its holding in each tranche and the variability it expects to absorb, as well as other relevant facts and circumstances. The likelihood of loss is not necessarily relevant to the determination of significance, and therefore, “significant” does not imply that there is high likelihood of loss. The maximum exposure to loss that is discussed in this section refers to the maximum loss that the Group could possibly be required to record in its consolidated statements of income as a result of its involvement with the VIEs. This represents exposures associated with both on-balance-sheet off-balance-sheet The table below shows the consolidated assets of the Group’s consolidated VIEs as well as total assets and maximum exposure to loss for its significant unconsolidated VIEs, as of March 31, 2019 and September 30, 2019: Consolidated VIEs Significant unconsolidated VIEs March 31, 2019 Consolidated assets Total assets Maximum (in billions of yen) Asset-backed commercial paper/loan programs 2,249 — — Asset-backed securitizations 571 70 8 Investments in securitization products 372 — — Investment funds 2,836 1,280 410 Trust arrangements and other 20 — — Total 6,048 1,350 418 Consolidated VIEs Significant unconsolidated VIEs September 30, 2019 Consolidated assets Total assets Maximum exposure to (in billions of yen) Asset-backed commercial paper/loan programs 2,325 — — Asset-backed securitizations 544 70 9 Investments in securitization products 371 — — Investment funds 2,680 1,600 476 Trust arrangements and other 19 — — Total 5,939 1,670 485 The Group has not provided financial or other support to consolidated or unconsolidated VIEs that the Group was not previously contractually required to provide. The tables below present the carrying amounts and classification of assets and liabilities on the MHFG Group’s balance sheets that relate to its variable interests in significant unconsolidated VIEs, as of March 31, 2019 and September 30, 2019: Assets on balance sheets related to unconsolidated VIEs: March 31, 2019 September 30, 2019 (in billions of yen) Trading account assets 104 107 Investments 168 171 Loans 71 122 Total 343 400 Liabilities on balance sheets and maximum exposure to loss related to unconsolidated VIEs: March 31, 2019 September 30, 2019 (in billions of yen) Payables under securities lending transactions 47 47 Trading account liabilities 1 1 Total 48 48 Maximum exposure to loss (Note) 418 485 Note: This represents the maximum amount the Group could possibly be required to record in its consolidated statements of income associated with on-balance-sheet off-balance-sheet Asset-backed commercial paper/loan programs The MHFG off-balance-sheet Asset-backed securitizations The MHFG Group acts as an arranger of various types of structured finance schemes to meet its clients’ needs for off-balance-sheet In addition, the MHFG Group establishes several single-issue and multi-issue special purpose entities that issue collateralized debt obligations (“CDO”) or CLO, synthetic CDO/CLO or other repackaged instruments to meet clients’ and investors’ financial needs. The MHFG Group also arranges securitization transactions including CMBS, RMBS and others. In these transactions, the MHFG Group acts as an underwriter, placement agent, asset manager, derivatives counterparty, and/or investor in debt and equity instruments. In certain VIEs, where the MHFG Group provides liquidity and credit support facilities, writes credit protection or invests in debt or equity instruments in its role as an arranger, servicer, administrator or asset manager, etc., the Group has the power to determine which assets will be held by the VIEs or to manage and monitor these assets. In addition, through the variable interests above, the Group has the obligation to absorb losses and the right to receive benefits that could potentially be significant to the VIEs. Therefore, the Group consolidates such VIEs. The MHFG Group established certain VIEs to securitize its own mortgage loans. The Group provides servicing for and holds retained subordinated beneficial interests in the securitized mortgage loans. In addition, the Group retains credit exposure in the form of guarantees on these loans. In its role as a servicer, the Group has the power to direct the entity’s activities that most significantly impact the entity’s economic performance by managing defaulted mortgage loans. In addition, through its retained interests and its aforementioned involvement as a guarantor, the Group has the obligation to absorb losses and the right to receive benefits that could potentially be significant to the entity. Therefore, the Group consolidates such VIEs. Investments in securitization products The MHFG Group invests in, among other things, various types of CDO/CLO, synthetic CDO/CLO and repackaged instruments, CMBS and RMBS arranged by third parties for the purpose of generating current income or capital appreciation, which all utilize entities that are deemed to be VIEs. By design, such investments were investment grade at issuance and held by a diverse group of investors. The potential loss amounts of the securities and the loans are generally limited to the amounts invested because the Group has no contractual involvement in such VIEs beyond its investments. Since the Group is involved in these VIEs only as an investor, the Group does not ordinarily have the power to direct the VIEs’ activities that most significantly impact the VIEs’ economic performance. However, the Group consolidates VIEs, where the transactions are tailored by the third party arrangers to meet the Group’s needs as a main investor, who is ultimately deemed to have the power to determine which assets are to be held by the VIEs. The Group also invests in certain beneficial interests issued by VIEs which hold real estate that the Group utilizes. In addition to these variable interests, when the Group has the power including the sole unilateral ability to liquidate the VIEs, the Group consolidates such VIEs. Investment funds The MHFG Group invests in various investment funds, including securities investment trusts, which collectively invest in equity and debt securities that include listed Japanese securities and investment grade bonds. Investment advisory companies or fund management companies, including the Group’s subsidiaries and affiliates, administer and make investment decisions about such investment funds. The Group determines whether it is the primary beneficiary by evaluating whether it has both (1) the power to make investment decisions about the investment funds and (2) the obligation to absorb losses or the right to receive benefits that could potentially be significant to the investment funds. The Group consolidates certain investment funds where it is deemed to be the primary beneficiary. Trust arrangements The MHFG Group offers a variety of asset management and administration services under trust arrangements including security investment trusts, pension trusts and trusts used in the securitization of assets originated by and transferred to third parties. The Group receives trust fees for providing services as an agent or fiduciary on behalf of beneficiaries. With respect to guaranteed principal money trust products, the MHFG Group assumes certain risks by providing guarantees for the repayment of principal as required by the trust agreements or relevant Japanese legislation. The MHFG Group manages entrusted funds primarily through the origination of high quality loans and other credit-related products, investing in investment grade marketable securities such as Japanese government bonds and placing cash with the MHFG Group’s subsidiary trust banks. The Group has the power to determine which assets will be held by the VIEs or to manage these assets. In addition, through the principal guarantee agreements, the Group has the obligation to absorb losses that could potentially be significant to the VIEs. Therefore, the Group consolidates such VIEs. However, the MHFG Group does not consolidate certain guaranteed principal money trusts, which invest all the entrusted funds in the MHFG Group itself, as the Group has determined that it has no variable interests. See Note 14 “Commitments and contingencies” for the balances of guaranteed trust principal that are not consolidated at March 31, 2019 and September 30, 2019. With respect to non-guaranteed non-guaranteed Special purpose entities created for structured finance The MHFG Group is involved in real estate, commercial aircraft and other vessel and machinery and equipment financing to VIEs. As the Group typically only provides senior financing with credit enhanced by subordinated interests and may sometimes act as an interest rate swap counterparty, the Group has determined that it does not have the power to direct the activities of the VIEs that most significantly impact the VIEs’ economic performance, or it does not have significant variable interests. Therefore, the Group does not consolidate such VIEs. Funding Vehicles The MHFG Group has established several wholly-owned off-shore Securitization The MHFG Group engages in securitization activities and securitizes mortgage loans, other loans, government and corporate securities and other types of financial assets in the normal course of business. In these securitization transactions, the Group records the transfer of a financial asset as a sale when all the accounting criteria for a sale under ASC 860 , “Transfers and Servicing” (“ASC 860”) are met. These criteria are (1) the transferred financial assets are legally isolated from the Group’s creditors, (2) the transferee or beneficial interest holder has the right to pledge or exchange the transferred financial assets, and (3) the Group does not maintain effective control over the transferred financial assets. If all the criteria are not met, the transfer is accounted for as a secured borrowing. For the six months ended September 30, 2018 and 2019, the MHFG Group neither made significant transfers of financial assets nor recognized significant gains or losses in securitization transactions accounted for as sales. The Group did not retain significant interests in securitization transactions accounted for as sales as of March 31, 2019 and September 30, 2019. There are certain transactions where transfers of financial assets do not qualify for the aforementioned sales criteria and are accounted for as secured borrowings. These transferred assets continue to be carried on the consolidated balance sheets of the MHFG Group. Such assets are associated with securitization transactions and loan participation transactions, which amounted to ¥207 billion and ¥143 billion as of March 31, 2019, and ¥188 billion and ¥122 billion as of September 30, 2019, respectively. Liabilities associated with securitization and loan participation transactions are presented as Payables under securities lending transactions and Other short-term

Noninterest income

Noninterest income	6 Months Ended
	Sep. 30, 2019
Noninterest income	16. Noninterest income Details of Noninterest income for the six months ended September 30, 2018 and 2019 are as follows: Six months ended September 30, 2018 2019 (in millions of yen) Fee and commission income: Securities-related business (1) 79,138 64,498 Deposits and lending business (2) 70,647 76,179 Remittance business (1) 55,078 56,075 Asset management business (1) 49,818 48,291 Trust related business (1) 57,372 56,459 Agency business (1) 19,509 15,152 Guarantee related business (3) 14,234 13,898 Fees for other customer services (1) 67,931 73,440 Total Fee and commission income 413,727 403,992 Foreign exchange gains (losses)—net (3) 44,718 27,923 Trading account gains (losses)—net (2) 64,956 395,405 Investment gains (losses)—net: Debt securities (3) 2,485 31,092 Equity securities (3) 306,788 (126,648 ) Equity in earnings (losses) of equity method investees—net (3) 22,627 22,066 Gains on disposal of premises and equipment (3) 4,305 1,693 Other noninterest income (2) 48,950 34,839 Total 908,556 790,362 Notes: (1) These amounts are revenues from contracts within the scope of ASC 606, “Revenue from contracts with customers” (“ASC 606”). (2) Part of these amounts are considered to be revenues from contracts that are within the scope of ASC 606. (3) These amounts are revenues from contracts that do not meet the scope of ASC 606. Certain Fee and commission income, Trading account gains (losses)—net and Other noninterest income outlined in the table above are considered to be revenues from contracts that are within the scope of ASC 606. The MHFG Group disaggregates Fee and commission income, which is the main part of revenues within the scope of ASC 606, by type of business or service in the table above. Fee and commission income Securities-related business fees mainly consist of brokerage fees and commissions, and asset-based revenues. Brokerage fees and commissions mainly include fees earned from the execution of customer transactions and sales commissions of investment trusts. Brokerage fees and commissions are recognized at the point in time on transaction date. Asset-based revenues mainly include fees received from investment trust management companies in return for administration services, such as record keeping services, of investment trusts. The amounts of asset-based revenues are calculated based on customer’s net asset value and recognized over time in the period when the related service is provided. Deposits and lending business fees consist of deposit-related fees and lending-related fees. Deposit-related fees, which amounted to ¥7 billion for the six months ended September 30, 2019, are mostly Remittance business fees include service charges for domestic and international funds transfers and collections. These fees are recognized at the point in time when the related service is provided. Asset management business fees consist of investment trust management fees and investment advisory fees for investment trusts. These fees are received from investment trusts in return for asset management services and/or investment advisory services on behalf of customers. The amounts of these fees are calculated based on a percentage of customer’s net asset value. These fees are recognized over time in the period when the management and/or advisory service is provided and the amount is fixed. Trust related business fees consist of trust fees earned primarily through fiduciary asset management and administrative service and other trust-related fees, which amounted to ¥26 billion and ¥31 billion for the six months ended September 30, 2018, respectively, and ¥25 billion and ¥31 billion for the six months ended September 30, 2019, respectively. Fees for fiduciary asset management and administration services for corporate pension plans and investment funds are recognized over time in the period when the related service is provided. Other trust-related fees mainly include brokerage commissions of real estate property, sales commissions of beneficial interest in real estate trust and charges for stock transfer agent services. These fees are mainly earned on a transaction basis and recognized at the point in time when the related service is provided. Agency business fees mainly include administration service fees related to the MHFG Group’s agency business such as Japan’s principal public lottery program and revenues from standing proxy services. These fees are recognized at the point in time when the related service is provided. Fees for other customer services include various revenues such as sales commissions of life insurance, service charges for electronic banking, financial advisory fees, and service charges for software development. Sales commissions from life insurance sales are received from insurance companies in return for selling insurance products and recognized when the insurance product is sold to customers. Service charges for electronic banking are mainly monthly basic usage fees and recognized over the related transaction period. Financial advisory fees are recognized over time in the period when the related advisory service based on the contract is rendered. Service charges for software development are recognized over time according to the progress of the development. Trading account gains (losses)—net and Other noninterest income In addition to Fee and commission income, Trading account gains (losses)—net and Other noninterest income include certain revenues within the scope of ASC 606. Underwriting fees from trading securities, which amounted to ¥31 billion and ¥33 billion for the six months ended September 30, 2018 and 2019, respectively, are within the scope of ASC 606 and accounted for in Trading account gains (losses)—net. Underwriting fees are primarily recognized at the point in time and all consid erations of the transaction on t rade date or pricing date Contract balances relating to revenues from contracts with customers subject to ASC 606 Contract assets and receivables from contracts with customers subject to ASC 606 are recognized in Accrued income or accounts receivable of Other assets. As of March 31, 2019 and September 30, 2019, the balance of contract assets was not material. Contract liabilities are recognized in unearned income of Other liabilities. As of March 31, 2019 and September 30, 2019, the balance of contract liabilities was not material. Remaining performance obligations relating to revenues from contracts with customers subject to ASC 606 Remaining performance obligations are services that the MHFG Group has committed to provide in the future in connection with its contracts with customers. As of March 31, 2019 and September 30, 2019, the amount of expected revenues from current obligations to provide services in the future is not material. It excludes revenues from contracts less than one year or contracts that have provisions that allow the Group to recognize revenue at the amount it has the right to invoice.

Fair value

Fair value	6 Months Ended
	Sep. 30, 2019
Fair value	17. Fair value Fair value measurements ASC 820, “Fair Value Measurements” (“ASC 820”), defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. ASC 820 also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. In addition, ASC 820 precludes (1) the deferral of gains and losses at inception of certain derivative contracts whose fair value was not evidenced by market-observable data, and (2) the use of block discounts when measuring the fair value of instruments traded in an active market, which were previously applied to large holdings of publicly traded financial instruments. Fair value hierarchy ASC 820 specifies a hierarchy of valuation techniques based on whether the inputs to those valuation techniques are observable or unobservable. The standard describes three levels of inputs that may be used to measure fair value: Level 1 Quoted prices in active markets for identical assets or liabilities. Level 1 assets and liabilities include debt and equity securities and derivative contracts that are traded in an active exchange market. Level 2 Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 2 assets and liabilities include debt securities with quoted prices that are traded less frequently than exchange-traded instruments. If no quoted market prices are available, the fair values of debt securities and over-the-counter Level 3 Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. Valuation process The MHFG Group has established valuation policies which govern the principles of fair value measurements and the authority and duty of each department. The Group has also established procedure manuals which describe valuation techniques and related inputs for determining the fair values of various financial instruments. The policies require that the measurement of fair values be carried out in accordance with the procedures performed by the risk management departments or the back offices which are independent from the front offices. The policies also require the risk management departments to check and verify whether the valuation methodologies defined in the procedure manuals are fair and proper and the internal audit departments to periodically review the compliance with the procedures throughout the Group. Although the valuation methodologies and related inputs are consistently used from period to period, a change in the market environment sometimes leads to a change in the valuation methodologies and the inputs. For instance, a change in market liquidity due to a delisting or a new listing is one of the key drivers of revisions to the valuation methodologies and the inputs. The key drivers also include the availability or the lack of market observable inputs and the development of new valuation methodologies. Price verification performed through the Group’s internal valuation process has an important role in identifying whether the valuation methodologies and the inputs need to be changed. The internal valuation process over the prices broker-dealers provide, primarily for Japanese securitization products, is described in more detail below in Available-for-sale The following is a description of valuation methodologies and inputs used for assets and liabilities measured at fair value on a recurring basis, including the general classification of such instruments pursuant to the fair value hierarchy and the MHFG Group’s valuation techniques used to measure fair values. During the six months ended September 30, 2019, there were no significant changes made to the Group’s valuation techniques and related inputs. Trading securities and trading securities sold, not yet purchased When quoted prices for identical securities are available in an active market, the Group uses the quoted prices to measure the fair values of securities and such securities are classified in Level 1 of the fair value hierarchy. Level 1 securities include highly liquid government bonds and equity securities. When quoted prices for identical securities are available, but not actively traded, such securities are classified in Level 2 of the fair value hierarchy. When no quoted market prices are available, the Group estimates fair values by using pricing models with inputs that are observable in the market and such securities are classified in Level 2 of the fair value hierarchy. Level 2 securities include Japanese local government bonds, corporate bonds, and commercial paper. When less liquid market conditions exist for securities, the quoted prices are stale or the prices from independent sources vary significantly, such securities are generally classified in Level 3 of the fair value hierarchy. The fair values of securitization products such as RMBS, CMBS, ABS, and CLO are determined primarily by using a discounted cash flow model. The key inputs used for the model include default rates, recovery rates, prepayment rates, and discount rates. In the event that certain key inputs are unobservable or cannot be corroborated by observable market data, these financial instruments are classified in Level 3. Hedge funds the Group invests in are primarily multi strategy funds that employ a fundamental bottom-up investment approach across various asset classes globally. Hedge funds are measured at the net asset value (“NAV”) per share and the Group has the ability to redeem its investment with the investees at the NAV per share at the measurement date or within the near term. Private equity funds have specific investment objectives in connection with their acquisition of equity interests in new and emerging firms in need of capital. Employing venture capital strategies, they provide financing and other support to start-up businesses, medium and small entities in particular geographical areas, and to companies with certain technologies or companies in high-growth industries. Real estate funds invest globally and primarily in real estate companies, debt recapitalizations and direct property. Private equity funds and real estate funds are measured using the NAV per share practical expedient and the Group does not have the ability to redeem its investment in the investees at the NAV per share at the measurement date or within the near term. It is estimated that the underlying assets of the funds would be liquidated within a ten-year Derivative financial instruments Exchange-traded derivatives are valued using quoted market prices and consequently are classified in Level 1 of the fair value hierarchy. However, the majority of derivatives entered into by the Group are executed over-the-counter over-the-counter quality. The Group calculates these credit-risk valuation adjustments using modeled expected exposure, and default probabilities and severity factors that are developed from market credit spreads and other related market information. Available-for-sale The fair values of available-for-sale non-binding Equity securities Equity securities mainly consist of marketable equity securities. The fair values of the marketable equity securities are based upon quoted market prices for identical equity securities trading as securities in an active market. Equity securities also include investments in certain investment funds measured using the NAV per share practical expedient including private equity funds and real estate funds .These securities are determined primarily using the same procedures described under Trading securities and trading securities sold, not yet purchased Other investments Other investments consist of investments held by consolidated investment companies. These companies typically hold investments in marketable and non-marketable non-marketable Non-marketable Long-term debt Fair value accounting is elected for certain long-term debt instruments with embedded derivatives. The fair values are determined using a discounted cash flow model that considers the embedded derivatives and the terms and payment structures of the notes. The fair values of the derivatives embedded in such notes are primarily derived by using the same procedures described in Derivative financial instruments Items measured at fair value on a recurring basis Assets and liabilities measured at fair value on a recurring basis at March 31, 2019 and September 30, 2019, including those for which the MHFG Group has elected the fair value option, are summarized below: March 31, 2019 Level 1 Level 2 Level 3 Assets/ Liabilities measured at (in billions of yen) Assets: Trading securities (1) Japanese government bonds 1,829 33 — 1,862 Japanese local government bonds — 134 — 134 U.S. Treasury bonds and federal agency securities 1,069 138 — 1,207 Other foreign government bonds 2,417 553 — 2,970 Agency mortgage-backed securities — 1,041 — 1,041 Residential mortgage-backed securities — — 11 11 Certificates of deposit and commercial paper — 1,047 — 1,047 Corporate bonds and other (2) 36 1,806 1,044 2,886 Equity securities 1,297 — 28 1,325 Trading securities measured at net asset value (3) 631 Derivative financial instruments: Interest rate contracts 36 5,729 21 5,786 Foreign exchange contracts 9 1,927 23 1,959 Equity-related contracts 58 63 4 125 Credit-related contracts — 16 2 18 Other contracts 2 4 10 16 Available-for-sale Japanese government bonds 10,902 995 — 11,897 Japanese local government bonds — 210 — 210 U.S. Treasury bonds and federal agency securities 1,009 — — 1,009 Other foreign government bonds 456 886 — 1,342 Agency mortgage-backed securities — 544 — 544 Residential mortgage-backed securities — 61 40 101 Commercial mortgage-backed securities — — 500 500 Japanese corporate bonds and other debt securities — 1,629 120 1,749 Foreign corporate bonds and other debt securities — 678 103 781 Equity securities: Equity securities with readily determinable fair values 3,633 135 — 3,768 Equity securities measured at net asset value (3) 53 Other investments — — 35 35 Total assets measured at fair value on a recurring basis 22,753 17,629 1,941 43,007 Liabilities: Trading securities sold, not yet purchased 2,380 199 1 2,580 Derivative financial instruments: Interest rate contracts 38 5,564 8 5,610 Foreign exchange contracts 11 1,746 1 1,758 Equity-related contracts 82 51 9 142 Credit-related contracts — 16 1 17 Other contracts 1 4 9 14 Long-term debt (4) — 1,778 655 2,433 Total liabilities measured at fair value on a recurring basis 2,512 9,358 684 12,554 September 30, 2019 Level 1 Level 2 Level 3 Assets/ Liabilities measured at fair value (in billions of yen) Assets: Trading securities (1) : Japanese government bonds 2,506 28 — 2,534 Japanese local government bonds — 123 — 123 U.S. Treasury bonds and federal agency securities 2,089 223 — 2,312 Other foreign government bonds 1,638 625 — 2,263 Agency mortgage-backed securities — 1,962 — 1,962 Residential mortgage-backed securities — — 10 10 Certificates of deposit and commercial paper — 1,316 — 1,316 Corporate bonds and other (2) 41 1,559 1,137 2,737 Equity securities 1,081 — 30 1,111 Trading securities measured at net asset value (3) 1,001 Derivative financial instruments: Interest rate contracts 49 6,997 8 7,054 Foreign exchange contracts 7 2,324 11 2,342 Equity-related contracts 61 75 12 148 Credit-related contracts — 18 3 21 Other contracts 1 5 10 16 Available-for-sale securities: Japanese government bonds 10,600 827 — 11,427 Japanese local government bonds — 235 — 235 U.S. Treasury bonds and federal agency securities 1,001 — — 1,001 Other foreign government bonds 421 911 — 1,332 Agency mortgage-backed securities — 512 — 512 Residential mortgage-backed securities — 54 33 87 Commercial mortgage-backed securities — — 549 549 Japanese corporate bonds and other debt securities — 1,634 169 1,803 Foreign corporate bonds and other debt securities — 611 133 744 Equity securities : Equity securities with readily determinable fair values 3,350 123 — 3,473 Equity securities measured at net asset value (3) 61 Other investments — — 36 36 Total assets measured at fair value on a recurring basis 22,845 20,162 2,141 46,210 Liabilities: Trading securities sold, not yet purchased 2,571 196 — 2,767 Derivative financial instruments: Interest rate contracts 49 6,736 3 6,788 Foreign exchange contracts 7 2,194 1 2,202 Equity-related contracts 104 53 19 176 Credit-related contracts — 23 2 25 Other contracts 1 5 9 15 Long-term debt (4) — 2,016 646 2,662 Total liabilities measured at fair value on a recurring basis 2,732 11,223 680 14,635 Notes: (1) Trading securities include foreign currency denominated securities for which the MHFG Group elected the fair value option. (2) The amount includes CLO and convertible bonds, which are classified in Level 3. (3) In accordance with ASC 820, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented for these classes of assets are intended to permit the reconciliation of the fair value hierarchy to the amounts presented in the statements of financial position. The amounts of unfunded commitments related to these investments at March 31, 2019 and September 30, 2019 were ¥37 billion and ¥41 billion, respectively. (4) Amounts represent items for which the Group elected the fair value option or for which it applied the practicability exception. Items measured at fair value on a recurring basis using significant unobservable inputs (Level 3) The following table presents a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the six months ended September 30, 2018 and 2019: Six months ended September 30, 2018 April 1, 2018 Gains (losses) in Earnings Gains (losses) OCI Transfers into Level 3 Transfers out of Level 3 Purchases Sales Issuances Settle- ments September 30, 2018 Change in unrealized gains (losses) still held (6) (in billions of yen) Assets: Trading securities: Residential mortgage-backed securities 12 — (2) — — — — — — — 12 — Corporate bonds and other 1,013 31 (2) — — — 457 (242 ) — (154 ) 1,105 35 Equity securities 23 2 (2) — — — 5 (1 ) — — 29 — Derivative financial instruments, net (1) Interest rate contracts 21 1 (2) — — — — — — 1 23 2 Foreign exchange contracts 12 15 (2) — — — — — — (2 ) 25 17 Equity-related contracts 4 (4 ) (2) — — — — — — 14 14 — Credit-related contracts 1 (3 ) (2) — — — — — — 2 — — Available-for-sale Residential mortgage-backed securities 54 — (3) — (4) — — — — — (8 ) 46 — Commercial mortgage-backed securities 441 — (3) — (4) — — 57 (28 ) — (1 ) 469 — Japanese corporate bonds and other debt securities 163 10 (3) (8 ) (4) — — 7 (7 ) — (9 ) 156 10 Foreign corporate bonds and other debt securities 80 — (3) — (4) 61 — 4 — — — 145 — Other investments 38 1 (3) — — — 13 — — (11 ) 41 2 Liabilities: Trading securities sold, not yet purchased 4 1 (2) — — — (30 ) 29 — — 2 — Long-term debt 561 2 (5) 3 (4) 2 — — — 85 (31 ) 612 4 Six months ended September 30, 2019 April 1, 2019 Gains (losses) in Earnings Gains (losses) in OCI Transfers into Level 3 Transfers out of Level 3 Purchases Sales Issuances Settle- ments September 30, 2019 Change in unrealized gains (losses) still held (6) (in billions of yen) Assets: Trading securities: Residential mortgage-backed securities 11 — (2) — — — — — — (1 ) 10 — Corporate bonds and other 1,044 (15 ) (2) — — — 338 (105 ) — (125 ) 1,137 (14 ) Equity securities 28 2 (2) — — — 1 — — (1 ) 30 — Derivative financial instruments, net (1) Interest rate contracts 13 (9 ) (2) — — — — — — 1 5 (8 ) Foreign exchange contracts 22 (10 ) (2) — — — — — — (2 ) 10 (9 ) Equity-related contracts (5 ) 1 (2) — — — — — — (3 ) (7 ) 2 Credit-related contracts 1 — (2) — — — — — — — 1 — Other contracts 1 — (2) — — — — — — — 1 — Available-for-sale Residential mortgage-backed securities 40 — (3) — (4) — — — — — (7 ) 33 — Commercial mortgage-backed securities 500 — (3) 1 (4) — — 89 (35 ) — (6 ) 549 — Japanese corporate bonds and other debt securities 120 1 (3) 4 (4) — — 97 — — (53 ) 169 — Foreign corporate bonds and other debt securities 103 — (3) (5 ) (4) — — 38 — — (3 ) 133 — Other investments 35 1 (3) — — — 10 — — (10 ) 36 2 Liabilities: Trading securities sold, not yet purchased 1 — (2) — — — (9 ) 8 — — — — Long-term debt 655 (6 ) (5) — (4) 17 (6 ) — — 108 (134 ) 646 (10 ) Notes: (1) Total Level 3 derivative exposures have been netted on the table for presentation purposes only. (2) Gains (losses) in Earnings are reported in Trading account gains (losses)—net, Foreign exchange gains (losses)—net or Other noninterest income (expenses). (3) Gains (losses) in Earnings are reported in Investment gains (losses)—net. (4) Gains (losses) in OCI are reported in Other comprehensive income (loss). (5) Gains (losses) in Earnings are reported in Other noninterest income (expenses). (6) Amounts represent total gains or losses recognized in earnings during the period. These gains or losses were attributable to the change in fair value relating to assets and liabilities classified as Level 3 that were still held at September 30, 2018 and 2019. Transfers between levels Transfers of assets or liabilities between levels of the fair value hierarchy are assumed to occur at the beginning of the period. During the six months ended September 30, 2018, the transfers into Level 3 included ¥61 billion of Available-for-sale Available-for-sale During the six months ended September 30, 2019, the transfers into Level 3 included ¥17 billion of Long-term debt. observability one of the when valuing During the six months ended September 30, 2019, the transfers out of Level 3 included ¥6 billion of Long-term debt. Transfers out of Level 3 for Long-term debt were primarily due to changes in the observability of one of the inputs when valuing certain structured notes. Quantitative information about Level 3 fair value measurements The following table presents information about significant unobservable inputs related to the MHFG Group’s material classes of Level 3 assets and liabilities at March 31, 2019 and September 30, 2019: March 31, 2019 Products/Instruments Fair value Principal valuation technique Unobservable inputs Range of input values Weighted average (5) (in billions of yen, except for percentages and basis points) Trading securities and Available-for-sale Residential mortgage-backed securities 51 Discounted cash flow Price-based Prepayment rate Default rate Recovery rate Discount margin 4% - 19% 0% - 1% 100% - 100% 18bps - 170bps 8% 0% 100% 51bps Commercial mortgage-backed securities 500 Discounted cash flow Price-based Discount margin 9bps - 161bps 24bps Corporate bonds and other debt securities 1,267 Discounted cash flow Price-based Prepayment rate (1) Default rate (1) Recovery rate (1) Discount margin (1) Discount margin (2) 22% - 22% 2% - 2% 69% - 69% 48bps - 1,173bps 4 22% 2% 69% 134bps 295bps Derivative financial instruments, net: Interest rate contracts 13 Internal valuation model (3) IR – IR correlation Default rate (4) 23% - 100% 0% - 63% Foreign exchange contracts 22 Internal valuation model (3) FX – IR correlation FX – FX correlation Default rate (4) 9% - 55% 63% - 63% 0% - 63% Equity-related contracts (5 ) Internal valuation model (3) Equity – IR correlation Equity correlation Equity volatility 25% - 25% 40% - 100% 5% - 36% Credit-related contracts 1 Internal valuation model (3) Default rate Credit correlation 0% - 5% 29% - 100% Long-term debt 655 Internal valuation model (3) IR – IR correlation FX – IR correlation FX – FX correlation Equity – IR correlation Equity – FX correlation Equity correlation Equity volatility Default rate Credit correlation 23% - 100% 9% - 55% 63% - 63% 25% - 25% 55% - 88% 12% - 100% 5% - 49% 0% - 4% 20% - 100% September 30, 2019 Products/Instruments Fair value Principal valuation technique Unobservable inputs Range of input values Weighted average (5) (in billions of yen, except for percentages and basis points) Trading securities and Available-for-sale Residential mortgage-backed securities 43 Discounted cash flow Price-based Prepayment rate Default rate Recovery rate Discount margin 4% -18% 0% - 1% 100% -100% 10bps -170bps 7% 0% 100% 51bps Commercial mortgage-backed securities 549 Discounted cash flow Price-based Discount margin 7bps - 161bps 23bps Corporate bonds and other debt securities 1,439 Discounted cash flow Price-based Prepayment rate (1) Default rate (1) Recovery rate (1) Discount margin (1) Discount margin (2) 16% - 17% 0% - 2% 40% - 70% 41bps - 1,193bps 2bps - 630bps 16% 2% 69% 127bps 51bps Derivative financial instruments, net: Interest rate contracts 5 Internal valuation model (3) IR – IR correlation Default rate (4) 23% - 100% 0% - 63% Foreign exchange contracts 10 Internal valuation model (3) FX – IR correlation FX – FX correlation Default rate (4) -19% - 55% 61% - 61% 0% - 63% Equity-related contracts (7 ) Internal valuation model (3) Equity – IR correlation Equity – FX correlation Equity Equity volatility 25% - 25% 70% - 70% 29% - 100% 6% Credit-related contracts 1 Internal valuation model (3) Default rate Credit correlation 0% - 9% 30% - 100% Long-term debt 646 Internal valuation model (3) IR – IR correlation FX – IR correlation FX – FX correlation Equity – IR correlation Equity – FX correlation Equity correlation Equity volatility Default rate Credit correlation 23% - 100% 24% - 55% 61% - 61% 25% - 25% 0% - 70% 16% - 100% 6% - 61% 0% - 4% 15% - 100% Notes: (1) These inputs are mainly used for determining the fair values of securitization products such as CDO, CLO and ABS, other than RMBS and CMBS. (2) This input is mainly used for determining the fair values of Japanese corporate bonds and foreign corporate bonds. (3) Internal valuation model includes discounted cash flow models and the Black-Scholes option pricing model. (4) This input represents the counterparty default rate derived from the MHFG Group’s own internal credit analyses. (5) Weighted averages are calculated by weighting each input by the relative fair value of the respective financial instruments. IR = Interest rate FX = Foreign exchange Sensitivities to unobservable inputs and interrelationships between unobservable inputs The following is a description of the sensitivities and interrelationships of the significant unobservable inputs used to measure the fair values of Level 3 assets and liabilities. (1) Prepayment rate The prepayment rate is the estimated rate at which voluntary unscheduled repayments of the principal of the underlying assets are expected to occur. The movement of the prepayment rate is generally negatively correlated with borrower delinquency. A change in prepayment rate would impact the valuation of the fair values of financial instruments either positively or negatively, depending on the structure of financial instruments. (2) Default rate The default rate is an estimate of the likelihood of not collecting contractual payments. An increase in the default rate would generally be accompanied by a decrease in the recovery rate and an increase in the discount margin. It would also generally impact the valuation of the fair values of financial instruments negatively. (3) Recovery rate The recovery rate is an estimate of the percentage of contractual payments that would be collected in the event of a default. An increase in recovery rate would generally be accompanied by a decrease in the default rate. It would also generally impact the valuation of the fair values of financial instruments positively. (4) Discount margin The discount margin is the portion of the interest rate over a benchmark market interest rate such as LIBOR or swap rates. It primarily consists of a risk premium component which is the amount of compensation that market participants require due to the uncertainty inherent in the financial instruments’ cash flows resulting from credit risk. An increase in discount margin would generally impact the valuation of the fair values of financial instruments negatively. (5) Correlation Correlation is the likelihood of the movement of one input relative to another based on an established relationship. The change in correlation would impact the valuation of derivatives either positively or negatively, depending on the nature of the underlying assets. (6) Volatility Volatility is a measure of the expected change in variables over a fixed period of time. Some financial instruments benefit from an increase in volatility and others benefit from a decrease in volatility. Generally, for a long position in an option, an increase in volatility would result in an increase in the fair values of financial instruments. Items measured at fair value on a nonrecurring basis Certain assets and liabilities are measured at fair value on a nonrecurring basis. These assets and liabilities primarily include items that are measured at the lower of cost or fair value, and items that were initially measured at cost and have been written down to fair value as a result of impairment. The following table shows the fair value hierarchy for these items as of March 31, 2019 and September 30, 2019: March 31, 2019 Total Level 1 Level 2 Level 3 Aggregate cost (in billions of yen) Assets: Loans 125 — 41 84 177 Loans held-for-sale 3 — 3 — 3 Equity securities (without readily determinable fair values) 1 — — 1 1 Other investments 98 98 — — 104 Premises and equipment—net 9 — 4 5 34 Intangible assets — — — — 1 Total assets measured at fair value on a nonrecurring basis 236 98 48 90 320 September 30, 2019 Total Level 1 Level 2 Level 3 Aggregate cost (in billions of yen) Assets: Loans 128 — 8 120 171 Loans held-for-sale 62 — 62 — 64 Equity securities (without readily determinable fair values) 8 — — 8 2 Other investments 3 3 — — 5 Premises and equipment—net 1 — 1 — 5 Total assets measured at fair value on a nonrecurring basis 202 3 71 128 247 Note: The fair values may not be current as of the dates indicated, but rather as of the date the fair value change occurred. Accordingly, the carrying values may not equal current fair value. Loans in the table above have been impaired and measured based upon the observable market price of the loan or the fair value of the underlying collateral. Loans held-for-sale Equity securities (without readily determinable fair values) in the table above consist of non-marketable non-marketable non-marketable non-marketable Other investments in the table above include certain equity method investments which have been impaired and written down to fair value. The fair values of the impaired marketable equity method investments are determined by their quoted market prices. As the securities are traded on an active exchange market, they are classified as Level 1. Premises and equipment—net and Intangible assets in the table above have been impaired and written down to fair value. Fair value option The MHFG Group elected the fair value option for certain eligible financial instruments described below. Foreign currency denominated debt securities The MHFG Group elected the fair value option for foreign currency denominated debt securities to mitigate the volatility in earnings due to the difference in the recognition of foreign exchange risk between foreign currency denominated debt securities and financial liabilities. Following the election of the fair value option, these debt securities are reported as trading securities in Trading account assets. On April 1, 2018, the Group adopted ASU No.2016-01. Certain hybrid financial instruments The MHFG Group issues structured notes as part of its client-driven activities. Structured notes are debt instruments that contain embedded derivatives. The Group elected the fair value option for certain structured notes to mitigate accounting mismatches and to achieve operational simplifications. In addition, the Group measures certain notes that contain embedded derivatives at fair value under the practicability exception. These notes continue to be reported in Long-term debt and interest on these notes continues to be reported in Interest expense on long-term debt based on the contractual rates. The differences between the aggregate fair value of these notes and the aggregate unpaid principal balance of such instruments were ¥21 billion and ¥11 billion at March 31, 2019 and September 30, 2019, respectively. The net unrealized gains (losses) resulting from changes in fair values of these notes recorded in Other noninterest income (expenses) were of ¥8 billion and ¥2 billion for the six months ended September 30, 2018 and 2019, respectively. The Group records changes in fair value on these notes attributable to the instrument-specific credit risk in AOCI in accordance with ASU No.2016-01, Fair value of financial instruments ASC 825, “Financial Instruments” (“ASC 825”), requires the disclosure of the estimated fair value of financial instruments. The fair value of financial instruments is the amount that would be exchanged between willing parties, other than in a forced sale or liquidation. Quoted market prices, if available, are best utilized as estimates of the fair values of financial instruments. However, since no quoted market prices are available for certain financial instruments, fair values for such financial instruments have been estimated based on management’s assumptions, discounted cash flow models or other valuation techniques. Such estimation methods are described in more detail below. These estimates could be significantly affected by different sets of assumptions. There are certain limitations to management’s best judgment in estimating fair values of financial instruments and inherent subjectivity involved in estimation methodologies and assumptions used to estimate fair value. Accordingly, the net realizable or liquidation values could be materially different from the estimates presented below. The following is a description of the valuation methodologies used for estimating the fair value of financial assets and liabilities not carried at fair value on the MHFG Group’s consolidated balance sheets. Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions The carrying value of short-term financial assets, such as cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions approximates the fair value of these assets since they generally involve limited losses from credit risk or have short-term maturities with interest rates that approximate market rates. Investments The fair value of held-to-maturity available-for-sale non-marketable Loans Loans have been fair valued based on the type of loan, credit quality, prepayment assumptions and remaining maturity. The fair value of loans is determined based on discounted cash flows using interest rates approximating the MHFG Group’s current rates for similar loans. The fair value of collateral dependent impaired loans is determined based on the fair value of the underlying collateral. Other financial assets The carrying value of other financial assets, which primarily consist of accounts receivable from brokers, dealers, and customers for securities transactions, accrued income and collateral provided for derivative transactions, approximates the fair value of these assets since they generally involve limited losses from credit risk or have short-term maturities with interest rates that approximate market rates. The majority of other financial assets is classified as Level 2, and included in the table in Note 6 “Other assets and liabilities”. Noninterest-bearing deposits, call money and funds purchased, and payables un

Offsetting of financial assets

Offsetting of financial assets and financial liabilities	6 Months Ended
	Sep. 30, 2019
Offsetting of financial assets and financial liabilities	18. Offsetting of financial assets and financial liabilities Derivatives The MHFG Group enters into master netting arrangements such as International Swaps and Derivatives Association, Inc. (“ISDA”) or similar agreements with counterparties to manage mainly credit risks associated with counterparty default. If the predetermined events including counterparty default occur, these enforceable master netting arrangements or similar agreements give the Group the right to offset derivative receivables and derivative payables and related financial collateral such as cash and securities with the same counterparty. Repurchase and resale agreements and securities lending and borrowing transactions Repurchase and resale agreements and securities lending and borrowing transactions are generally covered by industry standard master repurchase agreements and industry standard master securities lending agreements with netting terms to manage mainly credit risks associated with counterparty default. In the event of default by the counterparty, these agreements with netting terms provide the Group with the right to offset receivables and payables related to such transactions with the same counterparty, and to liquidate the collateral held. The following table provides information about the offsetting of financial assets and financial liabilities at March 31, 2019 and September 30, 2019. The table includes derivatives, repurchase and resale agreements, and securities lending and borrowing transactions that are subject to enforceable master netting arrangements or similar agreements irrespective of whether or not they are offset on the Group’s consolidated balance sheets. Amounts not offset on the balance sheet (3) Gross amounts recognized Gross amounts offset on the balance sheet Net amounts presented on the balance sheet (2) Financial instruments (4) Cash collateral Net amounts (in billions of yen) March 31, 2019 Assets (1) Derivatives 7,403 — 7,403 (5,903 ) (528 ) 972 Receivables under resale agreements 12,589 — 12,589 (12,579 ) — 10 Receivables under securities borrowing transactions 1,921 — 1,921 (1,894 ) — 27 Total 21,913 — 21,913 (20,376 ) (528 ) 1,009 Liabilities (1) Derivatives 6,978 — 6,978 (5,766 ) (769 ) 443 Payables under repurchase agreements 14,312 — 14,312 (14,309 ) — 3 Payables under securities lending transactions 932 — 932 (931 ) — 1 Total 22,222 — 22,222 (21,006 ) (769 ) 447 September 30, 2019 Assets (1) Derivatives 9,026 — 9,026 (7,372 ) (466 ) 1,188 Receivables under resale agreements 13,401 — 13,401 (13,386 ) — 15 Receivables under securities borrowing transactions 2,316 — 2,316 (2,265 ) — 51 Total 24,743 — 24,743 (23,023 ) (466 ) 1,254 Liabilities (1) : Derivatives 8,545 — 8,545 (7,225 ) (893 ) 427 Payables under repurchase agreements 16,837 — 16,837 (16,798 ) — 39 Payables under securities lending transactions 1,024 — 1,024 (1,020 ) — 4 Total 26,406 — 26,406 (25,043 ) (893 ) 470 Notes: (1) Amounts relating to master netting arrangements or similar agreements where the MHFG Group does not have the legal right of set-off over-the-counter OTC-cleared (2) Derivative assets and liabilities are recorded in Trading account assets and Trading account liabilities, respectively. (3) Amounts do not exceed the net amounts presented on the balance sheet and do not include the effect of overcollateralization, where it exists. (4) For derivatives, amounts include derivative assets or liabilities and securities collateral that are eligible for offsetting under enforceable master netting arrangements or similar agreements.

Repurchase agreements and secur

Repurchase agreements and securities lending transactions accounted for as secured borrowings	6 Months Ended
	Sep. 30, 2019
Repurchase agreements and securities lending transactions accounted for as secured borrowings	19. Repurchase agreements and securities lending transactions accounted for as secured borrowings The following table shows the gross amounts of liabilities associated with repurchase agreements and securities lending transactions, by remaining contractual maturity at March 31, 2019 and September 30, 2019: Overnight and continuous Up to 30 days 31-90 Greater than 90 days Total (in billions of yen) March 31, 2019 Repurchase agreements 2,596 8,537 2,403 1,104 14,640 Securities lending transactions 1,012 473 — 313 1,798 Total 3,608 9,010 2,403 1,417 16,438 September 30, 2019 Repurchase agreements 6,727 6,976 1,858 1,779 17,340 Securities lending transactions 807 660 110 280 1,857 Total 7,534 7,636 1,968 2,059 19,197 The following table shows the gross amounts of liabilities associated with repurchase agreements and securities lending transactions, by class of underlying collateral at March 31, 2019 and September 30, 2019: Repurchase agreements Securities lending transactions (in billions of yen) March 31, 2019 Japanese government bonds and Japanese local government bonds 2,118 430 Foreign government bonds and foreign agency mortgage-backed securities 11,613 396 Commercial paper and corporate bonds 223 52 Equity securities 492 902 Other 194 18 Total (Note) 14,640 1,798 September 30, 2019 Japanese government bonds and Japanese local government bonds 3,097 471 Foreign government bonds and foreign agency mortgage-backed securities 13,272 597 Commercial paper and corporate bonds 268 52 Equity securities 495 720 Other 208 17 Total (Note) 17,340 1,857 Note: Amounts exceeded the gross amounts recognized in Note 18 “Offsetting of financial assets and financial liabilities” by ¥1,194 billion and ¥1,336 set-off The MHFG Group is required to post securities as collateral with a fair value equal to or in excess of the principal amount of the cash borrowed under repurchase agreements. For securities lending transactions, the Group receives collateral in the form of cash. These contracts involve risks, including (1) the counterparty may fail to return the securities at maturity and (2) the fair value of the securities posted may decline below the amount of the Group’s obligation and therefore the counterparty may require additional amounts. The Group attempts to mitigate these risks by entering into transactions mainly with central counterparty clearing houses which revalue assets and perform margin maintenance activities on a regular basis, diversifying the maturities and counterparties, and using mainly highly liquid securities.

Business segment information

Business segment information	6 Months Ended
	Sep. 30, 2019
Business segment information	20. Business segment information The MHFG Group consists of the following five in-house The services that each in-house Retail & Business Banking Company This company provides financial services for individual customers, small and medium-sized Corporate & Institutional Company This company provides financial services for large corporations, financial institutions and public corporations in Japan. Global Corporate Company This company provides financial services for Japanese overseas affiliated corporate customers and non-Japanese Global Markets Company This company invests in financial products with market risk, such as interest rate risk, equity risk, and credit risk. Asset Management Company This company develops financial products and provides financial services that match the asset management needs of its wide range of customers from individuals to institutional investors. The reportable segment information, set forth below, is derived from the internal management reporting systems used by management to measure the performance of the Group’s operating segments. Management measures the performance of each of the operating segments in accordance with internal managerial accounting rules and practices. In addition, the format and information are presented primarily on the basis of Japanese GAAP. Therefore, they are not consistent with the consolidated financial statements prepared in accordance with U.S. GAAP. A reconciliation is provided for the total amount of all business segments’ “Net business profits (losses) + Net gains (losses) related to ETFs and others” with income before income tax expense under U.S. GAAP, and the total amount of all business segments’ “Fixed assets” with the total amount of Premises and equipment—net, Goodwill, Intangible assets, and ROU assets related to operating leases included in Other assets reported under U.S. GAAP. “Fixed assets” pertaining to MHBK, MHTB , . MHFG (Consolidated) Six months ended (5) Retail & Business Banking Company Corporate & Institutional Company Global Corporate Company Global Markets Company Asset Management Company Others (4) Total (in billions of yen) Gross profits + Net gains (losses) related to ETFs and others (1) 345.0 223.1 190.3 237.7 25.0 30.4 1,051.5 General and administrative expenses (2) 360.0 103.5 115.6 105.6 13.9 24.1 722.7 Equity in earnings (losses) of equity method investees — net 14.4 0.6 2.8 — 0.6 1.0 19.4 Amortization of goodwill and others 0.2 0.2 0.2 1.2 4.0 1.0 6.8 Others — — — — — (10.4 ) (10.4 ) Net business profits (losses) (3) (0.8 ) 120.0 77.3 130.9 7.7 (4.1 ) 331.0 MHFG (Consolidated) Six months ended Retail & Business Banking Company Corporate & Institutional Company Global Corporate Company Global Markets Company Asset Management Company Others (4) Total (in billions of yen) Gross profits + Net gains (losses) related to ETFs and others (1) 322.3 221.9 208.0 231.5 23.2 15.9 1,022.8 General and administrative expenses (2) 328.0 104.3 120.7 103.4 14.4 17.6 688.4 Equity in earnings (losses) of equity method investees — net 6.7 1.1 6.0 — 0.6 4.7 19.1 Amortization of goodwill and others 0.2 0.2 0.2 1.2 3.9 1.0 6.7 Others — — — — — (5.9 ) (5.9 ) Net business profits (losses) (3) 0.8 118.5 93.1 126.9 5.5 (3.9 ) 340.9 Fixed assets (6) 491.2 214.9 173.3 91.9 0.1 730.2 1,701.6 Notes: (1) “Gross profits + Net gains (losses) related to ETFs and others” is reported instead of sales reported by general corporations. Gross profits is defined as the sum of net interest income, fiduciary income, net fee and commission income, net trading income and net other operating income. Net gains (losses) related to ETFs and others consist of net gains (losses) on ETFs held by MHBK and MHTB on their non-consolidated basis (losses) related to ETFs and others amounted to ¥39.9 billion and ¥(8.0) billion, respectively, of which ¥33.7 billion and ¥(11.2) billion , respectively. (2) “General and administrative expenses” excludes non-recurring losses. (3) Net business profits (losses) is used in Japan as a measure of the profitability of core banking operations and is defined as gross profits (as defined above) less general and administrative expenses plus equity in earnings (losses) of equity method investees—net and others. Measurement of net business profits (losses) is required for regulatory reporting to the Financial Services Agency of Japan. (4) “Others” includes the following items: • profits and expenses pertaining to consolidated subsidiaries that are not subject to allocation; • consolidating adjustments, including eliminating internal transaction between each segment; • Equity in earnings (losses) of equity method investees-net • profits and losses pertaining to derivative transactions that reflect the counterparty risk of the individual parties and other factors in determining fair market value. ( 5 The MHFG Group adopted certain enhancements, which were not significant individually or in the aggregate, to the Group’s segment allocation methods under internal managerial accounting rules and practices, and accordingly, the figures for the six months ended September 30, 2018 have been restated to reflect these current period enhancements. Furthermore, income and expenses of foreign branches of MHBK and foreign subsidiaries with functional currencies other than Japanese Yen have been translated for purposes of segment reporting using the budgeted foreign currency rates. Prior period comparative amounts for such foreign currency income and expenses have been translated using current period budgeted foreign currency rates. ( 6 “Fixed assets” is presented based on Japanese GAAP and corresponds to the total amount of the following U.S. GAAP accounts: Premises and equipment—net, Goodwill, Intangible assets, and ROU assets related to operating leases included in Other assets. The above table does not include other asset amounts because “Fixed assets” is the only balance sheet metric that management uses when evaluating and making decisions pertaining to the operating segments. “Fixed assets” has been allocated to each segment starting in the fiscal year ended March 31, 2019 to enhance management’s analysis of the Group’s operations. “Others” in “Fixed assets” includes assets of headquarters that have not been allocated to each segment, “Fixed assets” pertaining to consolidated subsidiaries that are not subject to allocation, consolidating adjustments, and others. Certain “Fixed assets” expenses have been allocated to each segment using reasonable allocation criteria. Reconciliation As explained above, the measurement bases of the internal management reporting systems and the income and expenses items included are different from the accompanying consolidated statements of income. Therefore, it is impracticable to present reconciliations of all the business segment’s information, other than net business profits, to the corresponding items in the accompanying consolidated statements of income. A reconciliation of “Net business profits (losses) + Net gains (losses) related to ETFs and others” for the six months ended September 30, 2018 and 2019 presented above to income before income tax expense shown on the consolidated statements of income and a reconciliation of “Fixed assets” at September 30, 2019 to the total amount of Premises and equipment—net, Goodwill, Intangible assets, and ROU assets related to operating leases included in Other assets are as follows: Six months ended September 30, 2018 2019 (in billions of yen) Net business profits (losses) + Net gains (losses) related to ETFs and others 331.0 340.9 Adjustment to reconcile management reporting to Japanese GAAP: General and administrative expenses (non-recurring 12.0 24.5 Expenses related to portfolio problems (including reversal of (provision for) general reserve for losses on loans) (20.8 ) (19.1 ) Gains on reversal of reserves for possible losses on loans, and others 50.6 7.9 Net gains (losses) related to stocks—Net gains (losses) related to ETFs and others 110.1 55.4 Net extraordinary gains 6.7 (5.0 ) Others (16.0 ) (13.1 ) Income before income tax expense under Japanese GAAP 473.6 391.5 Adjustment to reconcile Japanese GAAP to U.S. GAAP: Derivative financial instruments and hedging activities (75.4 ) 105.0 Investments 92.1 (163.9 ) Loans (4.2 ) — Allowances for loan losses and off-balance-sheet (10.5 ) 0.5 Premises and equipment (77.3 ) (51.5 ) Land revaluation 1.5 0.5 Business combinations 7.5 4.1 Pension liabilities (19.8 ) (27.3 ) Consolidation of variable interest entities 43.9 40.3 Foreign currency translation (8.5 ) 14.3 Others (5.3 ) (3.0 ) Income before income tax expense under U.S. GAAP 417.6 310.5 September 30, 2019 (in billions of yen) Fixed assets 1,701.6 U.S. GAAP adjustments 964.5 Premises and equipment—net, Goodwill, Intangible assets, and ROU assets related to operating leases included in Other assets 2,666.1 Note: The U.S. GAAP adjustments are primarily comprised of GAAP differences mainly from ROU assets related to operating leases not recognized under Japanese GAAP; internally developed software, which was impaired under Japanese GAAP; land, which was revalued under Japanese GAAP; and the consolidation of certain variable interest entities, which are not consolidated under Japanese GAAP.

Basis of presentation (Policies

Basis of presentation (Policies)	6 Months Ended
	Sep. 30, 2019
Basis of presentation	1. Basis of presentation Mizuho Financial Group, Inc. (“MHFG”) is a joint stock corporation with limited liability under the laws of Japan. MHFG, through its subsidiaries (“the MHFG Group”, or “the Group”), provides domestic and international financial services in Japan and other countries. For a discussion of the Group’s segment information, see Note 20 “Business segment information”. MHFG and its domestic subsidiaries as well as its foreign subsidiaries maintain their accounting records in accordance with the accounting standards of Japan and those standards of the countries in which they are domiciled. Certain adjustments and reclassifications have been incorporated in the accompanying consolidated financial statements to conform them to the accounting principles generally accepted in the United States of America (“U.S. GAAP”). The consolidated financial statements are stated in Japanese yen, the currency of the country in which MHFG is incorporated and principally operates. The accompanying consolidated financial statements include the accounts of MHFG and its subsidiaries. MHFG’s interim financial reporting period ends on September 30 and certain subsidiaries’ interim financial reporting periods end on June 30. The effect on the MHFG Group’s consolidated financial statements of all material events occurring at these subsidiaries through the date of each of the periods presented in the consolidated financial statements has been considered for adjustment and/or disclosure. When determining whether to consolidate investee entities, the MHFG Group performs an analysis of the facts and circumstances of the particular relationships between the MHFG Group and the investee entities as well as the ownership of voting shares. The consolidated financial statements also include the accounts of VIEs for which MHFG or its subsidiaries have been determined to be the primary beneficiary in accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 810, “Consolidation” (“ASC 810”). All significant intercompany transactions and balances have been eliminated upon consolidation. The MHFG Group accounts for investments in entities over which it has significant influence by using the equity method of accounting. These investments are included in Other investments and the Group’s proportionate share of income or loss is included in Equity in earnings (losses) of equity method investees—net. Certain comparative amounts for the prior period have been reclassified in order to conform to the current period’s presentation. The unaudited consolidated financial statements should be read in conjunction with the audited financial statements and related notes thereto included in the annual financial statements for the fiscal year ended March 31, 2019. Certain financial information that is normally included in annual financial statements prepared in accordance with U.S. GAAP, but is not required for interim reporting purposes, has been condensed or omitted.
Use of estimates	Use of estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect reported amounts and related disclosures. Specific areas, among others, requiring the application of management’s estimates and judgment include assumptions pertaining to the allowance for loan losses, allowance for losses on off-balance-sheet
Leases	Leases The MHFG Group, as a lessee, recognizes liabilities to make lease payments and right-of-use (“ROU”) assets representing its right to use the underlying assets for the lease term. The lease terms include periods covered by options to extend or terminate the lease that the Group is reasonably certain to exercise. The Group uses its incremental borrowing rates at the lease commencement to determine the lease liability, which is measured at the present value of future lease payments, when the rate implicit in the lease is not readily determinable. The Group has elected not to separate lease and non-lease components of a contract that is or contains a lease for its equipment leases. The Group has elected not to recognize ROU assets and liabilities for leases with terms of twelve months or less. For operating leases, the ROU assets and related liabilities are included in Other assets and Other liabilities, respectively, on the consolidated balance sheets. Expenses are recognized on a straight-line basis over the lease term and are included in Occupancy expenses on the consolidated statements of income. Variable lease payments not included in the ROU assets or the lease liabilities are recognized as incurred in Occupancy expenses. For finance leases, ROU assets and related liabilities are included in Premises and equipment and Long-term debt, respectively, on the consolidated balance sheets.

Investments (Tables)

Investments (Tables)	6 Months Ended
	Sep. 30, 2019
Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value of Available-for-Sale and Held-to-Maturity Securities	The amortized cost, gross unrealized gains and losses, and fair value of available-for-sale held-to-maturity Amortized cost Gross unrealized gains Gross unrealized losses Fair value (in millions of yen) March 31, 2019 Available-for-sale Debt securities: Japanese government bonds 11,888,510 11,259 2,998 11,896,771 Japanese local government bonds 208,308 1,671 87 209,892 U.S. Treasury bonds and federal agency securities 1,008,903 644 231 1,009,316 Other foreign government bonds 1,341,564 758 455 1,341,867 Agency mortgage-backed securities (1) 530,540 14,524 593 544,471 Residential mortgage-backed securities 99,904 1,420 191 101,133 Commercial mortgage-backed securities 495,313 4,914 104 500,123 Japanese corporate bonds and other debt securities 1,743,309 7,686 1,561 1,749,434 Foreign corporate bonds and other debt securities (2) 778,088 3,047 226 780,909 Total 18,094,439 45,923 6,446 18,133,916 Held-to-maturity Debt securities: Japanese government bonds 1,119,899 19,907 — 1,139,806 Agency mortgage-backed securities (3) 484,205 — 14,423 469,782 Total 1,604,104 19,907 14,423 1,609,588 September 30, 2019 Available-for-sale Debt securities: Japanese government bonds 11,419,982 11,130 4,247 11,426,865 Japanese local government bonds 234,345 986 169 235,162 U.S. Treasury bonds and federal agency securities 1,000,684 831 430 1,001,085 Other foreign government bonds 1,331,208 1,576 292 1,332,492 Agency mortgage-backed securities (1) 495,503 16,868 162 512,209 Residential mortgage-backed securities 85,672 1,694 152 87,214 Commercial mortgage-backed securities 543,378 5,850 117 549,111 Japanese corporate bonds and other debt securities 1,792,730 11,931 1,731 1,802,930 Foreign corporate bonds and other debt securities (2) 740,431 3,248 164 743,515 Total 17,643,933 54,114 7,464 17,690,583 Held-to-maturity Debt securities: Japanese government bonds 639,913 20,198 — 660,111 Agency mortgage-backed securities (3) 424,463 2 9,767 414,698 Total 1,064,376 20,200 9,767 1,074,809 Notes: (1) Agency mortgage-backed securities presented in this line consist of Japanese and Foreign agency mortgage-backed securities, of which the fair values were ¥517,330 million and ¥27,141 million, respectively, at March 31, 2019, and ¥ 512,144 65 (2) Other debt securities presented in this line primarily consist of Foreign negotiable certificates of deposit (“ NCDs”) and asset-backed securities (“ABS”), of which the total fair values were ¥246,503 million at March 31, 2019, and ¥ 226,899 (3) All Agency mortgage-backed securities presented in this line are Ginnie Mae securities.
Amortized Cost and Fair Value of Available-for-Sale and Held-to-Maturity Securities by Contractual Maturity	The amortized cost and fair value of available-for-sale held-to-maturity Amortized cost Due in one year or less Due after one year through five years Due after five years through ten years Due after ten years Total (in millions of yen) Available-for-sale Debt securities: Japanese government bonds 5,907,368 4,501,734 1,010,880 — 11,419,982 Japanese local government bonds 9,207 148,811 73,113 3,214 234,345 U.S. Treasury bonds and federal agency securities 957,039 43,645 — — 1,000,684 Other foreign government bonds 1,077,745 253,463 — — 1,331,208 Agency mortgage-backed securities — — — 495,503 495,503 Residential mortgage-backed securities — — — 85,672 85,672 Commercial mortgage-backed securities 3,379 187,887 331,837 20,275 543,378 Japanese corporate bonds and other debt securities 94,985 863,381 526,430 307,934 1,792,730 Foreign corporate bonds and other debt securities 376,288 286,206 75,099 2,838 740,431 Total 8,426,011 6,285,127 2,017,359 915,436 17,643,933 Held-to-maturity Debt securities: Japanese government bonds 159,987 439,916 40,010 — 639,913 Agency mortgage-backed securities — — — 424,463 424,463 Total 159,987 439,916 40,010 424,463 1,064,376 Fair value Due in one year or less Due after one year through five years Due after five years through ten years Due after ten years Total (in millions of yen) Available-for-sale Debt securities: Japanese government bonds 5,911,536 4,507,477 1,007,852 — 11,426,865 Japanese local government bonds 9,253 149,149 73,418 3,342 235,162 U.S. Treasury bonds and federal agency securities 957,493 43,592 — — 1,001,085 Other foreign government bonds 1,078,329 254,163 — — 1,332,492 Agency mortgage-backed securities — — — 512,209 512,209 Residential mortgage-backed securities — — — 87,214 87,214 Commercial mortgage-backed securities 3,385 189,294 336,106 20,326 549,111 Japanese corporate bonds and other debt securities 95,179 865,299 528,669 313,783 1,802,930 Foreign corporate bonds and other debt securities 376,852 288,497 75,328 2,838 743,515 Total 8,432,027 6,297,471 2,021,373 939,712 17,690,583 Held-to-maturity Debt securities: Japanese government bonds 160,192 458,337 41,582 — 660,111 Agency mortgage-backed securities — — — 414,698 414,698 Total 160,192 458,337 41,582 414,698 1,074,809
Gross Unrealized Losses and Fair Value of Available-for-Sale and Held-to-Maturity Securities, Aggregated by Length of Time that Individual Securities Have Been in a Continuous Unrealized Loss Position	The following table shows the gross unrealized losses and fair value of available-for-sale held-to-maturity Less than 12 months 12 months or more Total Fair value Gross unrealized losses Fair value Gross unrealized losses Fair value Gross unrealized losses (in millions of yen) March 31, 2019 Available-for-sale Debt securities: Japanese government bonds 2,296,536 1,441 1,332,688 1,557 3,629,224 2,998 Japanese local government bonds 9,752 32 38,873 55 48,625 87 U.S. Treasury bonds and federal agency securities 506,176 231 — — 506,176 231 Other foreign government bonds 438,771 321 26,782 134 465,553 455 Agency mortgage-backed securities (1) 466 2 37,706 591 38,172 593 Residential mortgage-backed securities — — 16,729 191 16,729 191 Commercial mortgage-backed securities 11,256 44 36,760 60 48,016 104 Japanese corporate bonds and other debt securities 417,825 924 440,937 637 858,762 1,561 Foreign corporate bonds and other debt securities 129,164 142 79,716 84 208,880 226 Total 3,809,946 3,137 2,010,191 3,309 5,820,137 6,446 Held-to-maturity Debt securities: Agency mortgage-backed securities (2) — — 469,782 14,423 469,782 14,423 Total — — 469,782 14,423 469,782 14,423 September 30, 2019 Available-for-sale Debt securities: Japanese government bonds 2,634,254 3,208 291,304 1,039 2,925,558 4,247 Japanese local government bonds 40,638 101 32,510 68 73,148 169 U.S. Treasury bonds and federal agency securities 381,789 430 — — 381,789 430 Other foreign government bonds 480,958 292 — — 480,958 292 Agency mortgage-backed securities (1) 1,248 2 10,280 160 11,528 162 Residential mortgage-backed securities 3,221 33 11,000 119 14,221 152 Commercial mortgage-backed securities 12,315 86 17,649 31 29,964 117 Japanese corporate bonds and other debt securities 332,240 945 469,373 786 801,613 1,731 Foreign corporate bonds and other debt securities 173,890 158 5,494 6 179,384 164 Total 4,060,553 5,255 837,610 2,209 4,898,163 7,464 Held-to-maturity Debt securities: Agency mortgage-backed securities (2) — — 412,250 9,767 412,250 9,767 Total — — 412,250 9,767 412,250 9,767 Notes: (1) Agency mortgage-backed securities presented in this line consist of Japanese and Foreign agency mortgage-backed securities, of which the fair values were ¥11,107 million and ¥27,065 million, respectively, at March 31, 2019, and ¥ 11,528 0 9 (2) All Agency mortgage-backed securities presented in this line are Ginnie Mae securities.
Realized Gains and Losses on Sales of Available-for-Sale Securities	The following table shows the realized gains and losses on sales of available-for-sale Six months ended September 30, 2018 2019 (in millions of yen) Gross realized gains 9,955 36,183 Gross realized losses (8,497 ) (6,167 ) Net realized gains (losses) on sales of available-for-sale 1,458 30,016
Summary of Details of Net Gains and Losses on Equity Securities	The following table shows the details of the net gains and losses on Equity securities for the six months ended September 30, 2018 and 2019 Six months ended September 30, 2018 2019 (in millions of yen) Net gains (losses) recognized during the period on equity securities 306,788 (126,648 ) Less: Net gains (losses) recognized during the period on equity securities sold during the period 116,308 (3,084 ) Unrealized gains (losses) recognized during the reporting period on equity securities still held at the reporting period 190,480 (123,564 )
Summary of Equity Securities Without Readily Determinable Fair Values	The following table shows carrying amounts e and cumulative amounts due to downward adjustments and impairments and upward adjustments, at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in millions of yen) Carrying amounts at the end of the period 212,270 227,142 Downward adjustments and impairments 1,413 1,843 Upward adjustments 2,373 8,756 The following table shows amounts recognized in earnings during the period due to downward adjustments and impairments and upward adjustments for e Six months ended September 30, 2018 2019 (in millions of yen) Downward adjustments and impairments 976 430 Upward adjustments 1,837 6,527
Summary of Composition of Other Investments	The following table summarizes the composition of Other investments at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in millions of yen) Equity method investments 354,268 372,006 Investments held by consolidated investment companies 35,472 36,229 Total 389,740 408,235

Loans (Tables)

Loans (Tables)	6 Months Ended
	Sep. 30, 2019
Loans Outstanding by Domicile and Industry of Borrower	The table below presents loans outstanding by domicile and industry of borrower at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in millions of yen) Domestic: Manufacturing 9,558,146 9,661,265 Construction and real estate 8,954,823 9,193,059 Services 5,113,386 5,486,164 Wholesale and retail 5,163,267 5,292,337 Transportation and communications 3,622,130 3,751,962 Banks and other financial institutions 4,303,231 4,460,760 Government and public institutions 2,358,904 2,186,690 Other industries (Note) 5,477,452 5,581,548 Individuals: Mortgage loans 8,950,216 8,753,545 Other 907,589 869,309 Total domestic 54,409,144 55,236,639 Foreign: Commercial and industrial 19,086,511 18,905,059 Banks and other financial institutions 9,126,392 9,489,618 Government and public institutions 296,872 338,037 Other 33,171 34,376 Total foreign 28,542,946 28,767,090 Total 82,952,090 84,003,729 Less: Unearned income and deferred loan fees - 152,147 147,538 Total loans before allowance for loan losses 82,799,943 83,856,191 Note: Other industries of d
Credit Quality Information of Loans Based on MHFG Group's Internal Rating System	The table below presents credit quality information of loans based on the MHFG Group’s internal rating system at March 31, 2019 and September 30, 2019: Normal obligors Watch obligors excluding special attention obligors (1) Corporate Retail (2) Other (3) Corporate Retail (2) Other (3) Impaired loans Total (in millions of yen) March 31, 2019 Domestic: Manufacturing 9,209,834 69,080 19,805 141,202 8,278 1,303 108,644 9,558,146 Construction and real estate 8,186,308 505,142 15,920 186,753 14,490 25 46,185 8,954,823 Services 4,761,724 165,643 3,281 90,578 18,586 1 73,573 5,113,386 Wholesale and retail 4,686,541 161,392 26,881 127,695 25,553 591 134,614 5,163,267 Transportation and communications 3,472,991 71,934 934 37,593 7,472 — 31,206 3,622,130 Banks and other financial institutions 4,262,125 1,534 72 28,881 319 — 10,300 4,303,231 Government and public institutions 2,358,899 5 — — — — — 2,358,904 Other industries (4) 3,131,072 2,450 2,323,197 7,725 421 3,633 8,954 5,477,452 Individuals 233,986 9,384,955 64,974 21,127 70,427 1,168 81,168 9,857,805 Total domestic 40,303,480 10,362,135 2,455,064 641,554 145,546 6,721 494,644 54,409,144 Foreign: Commercial and industrial 16,061,655 182 2,488,800 347,060 — 38,404 150,410 19,086,511 Banks and other financial institutions 8,623,103 — 492,831 10,458 — — — 9,126,392 Government and public institutions 296,870 — — — — — 2 296,872 Other 1,480 9,713 19,690 333 — 879 1,076 33,171 Total foreign 24,983,108 9,895 3,001,321 357,851 — 39,283 151,488 28,542,946 Total 65,286,588 10,372,030 5,456,385 999,405 145,546 46,004 646,132 82,952,090 September 30, 2019 Domestic: Manufacturing 9,299,310 66,098 14,732 123,362 7,921 542 149,300 9,661,265 Construction and real estate 8,452,801 486,803 11,751 179,437 12,710 — 49,557 9,193,059 Services 5,113,878 160,329 1,883 111,672 17,210 — 81,192 5,486,164 Wholesale and retail 4,839,416 152,789 17,127 123,201 24,216 605 134,983 5,292,337 Transportation and communications 3,608,666 67,073 283 45,291 7,920 — 22,729 3,751,962 Banks and other financial institutions 4,411,489 1,697 276 37,516 334 — 9,448 4,460,760 Government and public institutions 2,186,682 8 — — — — — 2,186,690 Other industries (4) 3,155,810 2,384 2,384,867 12,120 407 10,364 15,596 5,581,548 Individuals 191,099 9,182,326 63,795 36,061 66,080 1,098 82,395 9,622,854 Total domestic 41,259,151 10,119,507 2,494,714 668,660 136,798 12,609 545,200 55,236,639 Foreign: Commercial and industrial 16,104,914 292 2,367,172 317,303 — 33,750 81,628 18,905,059 Banks and other financial institutions 8,838,656 — 638,508 12,454 — — — 9,489,618 Government and public institutions 338,037 — — — — — — 338,037 Other 1,432 9,583 19,316 1,755 — 994 1,296 34,376 Total foreign 25,283,039 9,875 3,024,996 331,512 — 34,744 82,924 28,767,090 Total 66,542,190 10,129,382 5,519,710 1,000,172 136,798 47,353 628,124 84,003,729 Notes: (1) Special attention obligors are watch obligors with debt in TDR or 90 days or more delinquent debt. Loans to such obligors are considered impaired. (2) The primary component of the retail portfolio segment is mortgage loans to individuals which obligor category is classified based on past due status. The trigger to reclassify obligors from normal obligors to watch obligors excluding special attention obligors is when the past due status is more than 30 days. (3) Non-impaired o (4) Other industries of d
Impaired Loans Information	The table below presents impaired loans information at March 31, 2019 and September 30, 2019: Recorded investment (1) Requiring an allowance for loan losses Not requiring an allowance for loan losses (2) Total Unpaid principal balance Related allowance (3) Average recorded investment Interest income recognized (4) (in millions of yen) March 31, 2019 Domestic: Manufacturing 103,039 5,605 108,644 111,533 39,301 122,764 1,404 Construction and real estate 36,873 9,312 46,185 51,158 4,661 42,224 487 Services 64,021 9,552 73,573 79,736 16,311 67,679 1,058 Wholesale and retail 124,911 9,703 134,614 147,665 38,763 130,860 1,814 Transportation and communications 28,297 2,909 31,206 32,139 13,146 29,864 412 Banks and other financial institutions 6,473 3,827 10,300 10,300 1,327 10,671 109 Other industries 8,867 87 8,954 9,149 5,761 6,042 29 Individuals 37,488 43,680 81,168 88,331 2,630 86,082 1,326 Total domestic 409,969 84,675 494,644 530,011 121,900 496,186 6,639 Foreign: Total foreign (5) 119,079 32,409 151,488 164,984 47,345 113,559 1,518 Total 529,048 117,084 646,132 694,995 169,245 609,745 8,157 Recorded investment (1) Requiring an allowance for loan losses Not requiring an allowance for loan losses (2) Total Unpaid principal balance Related allowance (3) Average recorded investment Interest income recognized (4) (in millions of yen) September 30, 2019 Domestic: Manufacturing 100,021 49,279 149,300 152,358 35,530 128,972 796 Construction and real estate 39,756 9,801 49,557 56,503 8,491 47,871 279 Services 72,044 9,148 81,192 86,259 16,689 77,383 460 Wholesale and retail 125,938 9,045 134,983 151,913 43,339 134,798 850 Transportation and communications 20,272 2,457 22,729 23,628 6,534 26,968 212 Banks and other financial institutions 5,688 3,760 9,448 9,447 1,001 9,874 51 Other industries 15,323 273 15,596 15,720 6,290 12,275 96 Individuals 40,352 42,043 82,395 87,189 3,317 81,781 584 Total domestic 419,394 125,806 545,200 583,017 121,191 519,922 3,328 Foreign: Total foreign (5) 55,639 27,285 82,924 96,539 31,200 117,206 1,398 Total 475,033 153,091 628,124 679,556 152,391 637,128 4,726 Notes: (1) Amounts represent the outstanding balances of nonaccrual loans. The MHFG Group’s policy for placing loans in nonaccrual status corresponds to the Group’s definition of impaired loans. (2) These impaired loans do not require an allowance for loan losses because the MHFG Group has sufficient collateral to cover probable loan losses. (3) The allowance for loan losses on impaired loans includes the allowance for groups of loans which were collectively evaluated for impairment, in addition to the allowance for those loans that were individually evaluated for impairment. The total carrying amount of the groups of loans which were collectively evaluated for impairment at March 31, 2019 and September 30, 2019 was ¥257,099 million and ¥250,121 million, respectively. (4) Amounts represent the amount of interest income on impaired loans recognized on a cash basis and included in Interest income on loans in the consolidated statements of income. (5) The majority of t c i
Troubled Debt Restructurings Entered Modified Periods by Type of Concession Granted	The following table presents modified loans that were determined to be TDRs during the six months ended September 30, 2018 and 2019: Loan forgiveness or debt to equity swaps Interest rate reduction and/or postponement of principal and/or Recorded investment (1) (in millions of yen) September 30, 2018 Domestic: Manufacturing — — 51,161 Construction and real estate — — 7,764 Services — — 29,203 Wholesale and retail — — 75,593 Transportation and communications — — 13,999 Banks and other financial institutions — — 7,160 Individuals — — 8,866 Total domestic — — 193,746 Foreign: Total foreign (2) 1,008 2,012 9,493 Total 1,008 2,012 203,239 September 30, 2019 Domestic: Manufacturing 689 3,806 57,879 Construction and real estate — — 15,478 Services — — 44,185 Wholesale and retail — — 77,117 Transportation and communications — — 7,916 Banks and other financial institutions — — 7,639 Other industries — — 639 Individuals — — 8,074 Total domestic 689 3,806 218,927 Foreign: Total foreign (2) 470 4,922 38,646 Total 1,159 8,728 257,573 Notes: (1) Amounts represent the book values of loans immediately after the restructurings. (2) The majority of t c i
Payment Defaults Occurred During Periods with Respect to Loans Modified as Troubled Debt Restructurings within Previous Twelve Months	The following table presents payment defaults which occurred during the six months ended September 30, 2018 and 2019 with respect to the loans modified as TDRs within the previous twelve months: Recorded investment September 30, 2018 September 30, 2019 (in millions of yen) Domestic: Manufacturing 383 2,391 Construction and real estate 390 171 Services 714 318 Wholesale and retail 6,700 6,504 Transportation and communications 409 86 Other industries — — Individuals 2,241 884 Total domestic 10,837 10,354 Foreign: Total foreign — 6,436 Total 10,837 16,790
Age Analysis of Past Due Loans	The table below presents an analysis of the age of the recorded investment in loans that are past due at March 31, 2019 and September 30, 2019: 30-59 days past due 60-89 days past due 90 days or more past due Total past due Current Total (in millions of yen) March 31, 2019 Domestic: Manufacturing 2,210 513 7,036 9,759 9,548,387 9,558,146 Construction and real estate 1,010 1,054 31,092 33,156 8,921,667 8,954,823 Services 633 196 3,494 4,323 5,109,063 5,113,386 Wholesale and retail 1,614 1,415 7,868 10,897 5,152,370 5,163,267 Transportation and communications 363 256 2,119 2,738 3,619,392 3,622,130 Banks and other financial institutions 3 484 6 493 4,302,738 4,303,231 Government and public institutions — — — — 2,358,904 2,358,904 Other industries 2 — 57 59 5,477,393 5,477,452 Individuals 27,139 11,013 28,965 67,117 9,790,688 9,857,805 Total domestic 32,974 14,931 80,637 128,542 54,280,602 54,409,144 Foreign: Total foreign (Note) 668 211 26,316 27,195 28,515,751 28,542,946 Total 33,642 15,142 106,953 155,737 82,796,353 82,952,090 September 30, 2019 Domestic: Manufacturing 733 983 7,601 9,317 9,651,948 9,661,265 Construction and real estate 834 849 28,678 30,361 9,162,698 9,193,059 Services 390 2,986 5,171 8,547 5,477,617 5,486,164 Wholesale and retail 2,317 1,226 11,460 15,003 5,277,334 5,292,337 Transportation and communications 106 366 2,154 2,626 3,749,336 3,751,962 Banks and other financial institutions 116 — 41 157 4,460,603 4,460,760 Government and public institutions — — — — 2,186,690 2,186,690 Other industries — — 221 221 5,581,327 5,581,548 Individuals 22,918 26,303 32,367 81,588 9,541,266 9,622,854 Total domestic 27,414 32,713 87,693 147,820 55,088,819 55,236,639 Foreign: Total foreign (Note) 1,181 249 25,936 27,366 28,739,724 28,767,090 Total 28,595 32,962 113,629 175,186 83,828,543 84,003,729 Note: The majority of t c i

Allowance for loan losses (Tabl

Allowance for loan losses (Tables)	6 Months Ended
	Sep. 30, 2019
Changes in Allowance for Loan Losses, Allowance for Loan Losses and Loans Outstanding Disaggregated on Basis of Impairment Method, by Portfolio Segment	Changes in Allowance for loan losses by portfolio segment for the six months ended September 30, 2018 and 2019 are shown below: Corporate Retail Other Total (in millions of yen) Six months ended September 30, 2018 Balance at beginning of period 249,072 28,192 32,638 309,902 Provision (credit) for loan losses (13,435 ) (2,290 ) 2,445 (13,280 ) Charge-offs (27,419 ) (1,243 ) (2,602 ) (31,264 ) Recoveries 4,914 220 2,409 7,543 Net charge-offs (22,505 ) (1,023 ) (193 ) (23,721 ) Others (Note) 2,519 — (931 ) 1,588 Balance at end of period 215,651 24,879 33,959 274,489 Six months ended September 30, 2019 Balance at beginning of period 252,903 23,230 31,068 307,201 Provision (credit) for loan losses 17,275 (805 ) (2,697 ) 13,773 Charge-offs (24,288 ) (1,397 ) (3,349 ) (29,034 ) Recoveries 2,724 309 1,021 4,054 Net charge-offs (21,564 ) (1,088 ) (2,328 ) (24,980 ) Others (Note) (3,887 ) — (685 ) (4,572 ) Balance at end of period 244,727 21,337 25,358 291,422 Note: Others includes primarily foreign exchange translation. The table below presents Allowance for loan losses and loans outstanding by portfolio segment disaggregated on the basis of impairment method at March 31, 2019 and September 30, 2019: Corporate Retail Other Total (in millions of yen) March 31, 2019 Allowance for loan losses 252,903 23,230 31,068 307,201 of which individually evaluated for impairment 139,472 2,122 8,933 150,527 of which collectively evaluated for impairment 113,431 21,108 22,135 156,674 Loans (Note) 66,804,088 10,596,994 5,551,008 82,952,090 of which individually evaluated for impairment 539,893 20,886 54,319 615,098 of which collectively evaluated for impairment 66,264,195 10,576,108 5,496,689 82,336,992 September 30, 2019 Allowance for loan losses 244,727 21,337 25,358 291,422 of which individually evaluated for impairment 124,693 1,884 5,338 131,915 of which collectively evaluated for impairment 120,034 19,453 20,020 159,507 Loans (Note) 68,067,130 10,343,150 5,593,449 84,003,729 of which individually evaluated for impairment 547,792 20,099 35,617 603,508 of which collectively evaluated for impairment 67,519,338 10,323,051 5,557,832 83,400,221 Note: Amounts represent loan balances before deducting unearned income and deferred loan fees.

Other assets and liabilities (T

Other assets and liabilities (Tables)	6 Months Ended
	Sep. 30, 2019
Details of Other Assets and Liabilities	The following table sets forth the details of other assets and liabilities at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in millions of yen) Other assets: Accounts receivable: Receivables from brokers, dealers and customers for securities transactions (1) 1,517,235 1,348,181 Other 400,676 358,547 Collateral pledged: Collateral pledged for derivative transactions 856,439 1,008,596 Margins provided for futures contracts 159,747 269,143 Other 857,814 865,875 Prepaid pension cost 850,472 860,365 ROU assets (2) — 647,185 Security deposits 123,317 108,293 Loans held for sale 24,921 68,569 Other 485,383 473,301 Total 5,276,004 6,008,055 Other liabilities: Accounts payable: Payables to brokers, dealers and customers for securities transactions (1) 2,572,315 2,042,447 Other 442,776 451,208 Guaranteed trust principal ( 3 809,450 813,761 Lease Liabilities (2) — 656,409 Collateral accepted: Collateral accepted for derivative transactions 589,411 533,308 Margins accepted for futures contracts 339,863 541,070 Unearned income ( 4 126,594 120,908 Other 1,052,297 1,024,549 Total 5,932,706 6,183,660 Notes: (1) Receivables from brokers, dealers and customers for securities transactions included ¥555,938 million and ¥181,535 million of such receivables of consolidated VIEs at March 31, 2019 and September 30, 2019, respectively. Payables to brokers, dealers and customers for securities transactions included ¥620,766 million and ¥172,473 million of such payables of consolidated VIEs at March 31, 2019 and September 30, 2019, respectively. (2) ROU assets and lease liabilities were recognized in connection with the adoption of ASU No.2016-02 on April 1, 2019. See Note 1 “Basis of presentation” and Note 2 “Recently issued accounting pronouncements” for further information. ( 3 Guaranteed trust principal is the liability of certain consolidated trust arrangements that meet the definition of a VIE for which the MHFG Group provides guarantees for the repayment of principal. See Note 15 “Variable interest entities and securitizations” for further discussion of the guaranteed principal money trusts. (4) Unearned income is primarily comprised of loan fees received from consumer loan customers when loans are made. This income is being deferred and recognized in earnings over the life of the loan.

Preferred and common stock (Tab

Preferred and common stock (Tables)	6 Months Ended
	Sep. 30, 2019
Preferred stock
Schedule of Stock by Class	The composition of preferred stock at March 31, 2019 and September 30, 2019 is as follows: Class of stock March 31, 2019 September 30, 2019 Authorized Issued Authorized Issued (number of shares) Class XIV preferred stock 900,000,000 — 900,000,000 — Class XV preferred stock 900,000,000 — 900,000,000 — Class XVI preferred stock 1,500,000,000 — 1,500,000,000 —
Common Stock
Schedule of Stock by Class	The following table shows the changes in the number of issued shares of common stock during the fiscal year ended March 31, 2019 and the six months ended September 30, 2019: March 31, 2019 September 30, 2019 (number of shares) Balance at beginning of period 25,389,644,945 25,392,498,945 Issuance of new shares of common stock due to exercise of stock acquisition rights 2,854,000 — Balance at end of period 25,392,498,945 25,392,498,945

Accumulated other comprehensi_2

Accumulated other comprehensive income, net of tax (Tables)	6 Months Ended
	Sep. 30, 2019
Changes in Each Component of AOCI	Changes in each component of AOCI for the six months ended September 30, 2018 and 2019 are as follows: Six months ended September 30, 2018 2019 (in millions of yen) AOCI, balance at beginning of period, previously reported 1,741,894 164,021 Cumulative effect of change in accounting principles (1) (1,535,142 ) (1,052 ) AOCI, balance at beginning of period, adjusted 206,752 162,969 Net unrealized gains (losses) on available-for-sale Balance at beginning of period, previously reported 1,556,585 22,019 Cumulative effect of change in accounting principles (1) (1,525,064 ) — Balance at beginning of period, adjusted 31,521 22,019 Unrealized holding gains (losses) during period (25,155 ) 25,843 Less: reclassification adjustments for losses (gains) included in net income (862 ) (20,824 ) Change during period (26,017 ) 5,019 Balance at end of period 5,504 27,038 Foreign currency translation adjustments: Balance at beginning of period, previously reported (35,076 ) (58,558 ) Cumulative effect of change in accounting principles (1) — (1,052 ) Balance at beginning of period, adjusted (35,076 ) (59,610 ) Foreign currency translation adjustments during period 7,678 (63,466 ) Less: reclassification adjustments for losses (gains) included in net income — — Change during period 7,678 (63,466 ) Balance at end of period (27,398 ) (123,076 ) Pension liability adjustments: Balance at beginning of period 220,385 196,446 Unrealized gains (losses) during period (218 ) (1,720 ) Less: reclassification adjustments for losses (gains) included in net income (2,916 ) (2,130 ) Change during period (3,134 ) (3,850 ) Balance at end of period 217,251 192,596 Own credit risk adjustments (2) : Balance at beginning of period, previously reported — 4,114 Cumulative effect of change in accounting principles (1) (10,078 ) — Balance at beginning of period, adjusted (10,078 ) 4,114 Unrealized gains (losses) during period 2,656 7,320 Less: reclassification adjustments for losses (gains) included in net income (20 ) (1,277 ) Change during period 2,636 6,043 Balance at end of period (7,442 ) 10,157 Total other comprehensive income (loss), net of tax attributable to MHFG shareholders (18,837 ) (56,254 ) AOCI, balance at end of period 187,915 106,715 Notes: (1) See Note 2 “Recently issued accounting pronouncements” for further details of the cumulative-effect adjustment for AOCI. (2) The MHFG Group adopted ASU No.2016-01
Amounts Reclassified Out of Accumulated Other Comprehensive Income into Net Income	The following table shows the amounts reclassified out of AOCI into net income during the six months ended September 30, 2019: Six months ended September 30, 2019 Before tax (1) Tax effect (2) Net of tax before allocation to noncontrolling interests Net of tax attributable to noncontrolling interests (2) Net of tax attributable to MHFG shareholders (in millions of yen) Amounts reclassified out of AOCI into net income: Affected line items in the consolidated statements of income: Net unrealized gains (losses) on available-for-sale 30,013 (9,192 ) 20,821 3 20,824 Investment gains (losses)—net Pension liability adjustments 3,155 (937 ) 2,218 (88 ) 2,130 Salaries and employee benefits Own credit risk adjustments 1,921 (588 ) 1,333 (56 ) 1,277 Other noninterest income (expenses) Total 35,089 (10,717 ) 24,372 (141 ) 24,231 Notes: (1) The financial statement line item in which the amounts in the Before tax column are reported in the Consolidated statements of income is listed to the right of the table. (2) The financial statement line items in which the amounts in the Tax effect and the Net of tax attributable to noncontrolling interest columns are reported in the consolidated statements of income are Income tax expense and Net income, respectively.

Regulatory matters (Tables)

Regulatory matters (Tables)	6 Months Ended
	Sep. 30, 2019
Capital Adequacy Ratios of MHFG, MHBK, and MHTB Calculated in Accordance with Japanese GAAP and Guidelines Established by Financial Services Agency	Capital adequacy ratios and leverage ratios of MHFG, MHBK, and MHTB as of March 31, 2019 and September 30, 2019 calculated in accordance with Japanese GAAP and the guidelines established by the Financial Services Agency are set forth in the following table: March 31, 2019 September 30, 2019 Amount Ratio Amount Ratio (in billions of yen, except percentages) Consolidated: MHFG: Common Equity Tier 1 capital: Required (Note) 4,661 8.05 4,878 8.05 Actual 7,390 12.76 7,383 12.18 Tier 1 capital: Required (Note) 5,529 9.55 5,787 9.55 Actual 9,232 15.94 9,162 15.11 Total risk-based capital: Required (Note) 6,687 11.55 6,999 11.55 Actual 10,918 18.85 10,865 17.92 Leverage Ratio: Required 6,257 3.00 6,327 3.00 Actual 9,232 4.42 9,162 4.34 MHBK: Common Equity Tier 1 capital: Required 2,388 4.50 2,497 4.50 Actual 6,690 12.60 6,761 12.18 Tier 1 capital: Required 3,184 6.00 3,329 6.00 Actual 8,527 16.06 8,533 15.37 Total risk-based capital: Required 4,246 8.00 4,439 8.00 Actual 10,098 19.02 10,142 18.27 Leverage Ratio: Required 5,758 3.00 5,815 3.00 Actual 8,527 4.44 8,533 4.40 MHTB: Common Equity Tier 1 capital: Required 95 4.50 96 4.50 Actual 500 23.67 510 23.96 Tier 1 capital: Required 127 6.00 128 6.00 Actual 501 23.70 511 23.99 Total risk-based capital: Required 169 8.00 170 8.00 Actual 505 23.87 513 24.11 Leverage Ratio: Required 229 3.00 222 3.00 Actual 501 6.55 511 6.90 Non-consolidated: MHBK: Common Equity Tier 1 capital: Required 2,272 4.50 2,350 4.50 Actual 6,363 12.60 6,423 12.30 Tier 1 capital: Required 3,029 6.00 3,133 6.00 Actual 8,199 16.23 8,191 15.68 Total risk-based capital: Required 4,039 8.00 4,177 8.00 Actual 9,757 19.32 9,792 18.75 Leverage Ratio: Required 5,517 3.00 5,556 3.00 Actual 8,199 4.45 8,191 4.42 MHTB: Common Equity Tier 1 capital: Required 94 4.50 95 4.50 Actual 494 23.58 500 23.64 Tier 1 capital: Required 126 6.00 127 6.00 Actual 494 23.58 500 23.64 Total risk-based capital: Required 168 8.00 169 8.00 Actual 498 23.75 503 23.76 Leverage Ratio: Required 227 3.00 220 3.00 Actual 494 6.53 500 6.82 Note: The required ratios disclosed above, at March 31, 2019 and September 30, 2019, include the transitional capital conservation buffer of 2.5%, the countercyclical capital buffer of 0.05%, and the transitional additional loss absorbency requirements for global systemically important banks (“G-SIBs”) (“D-SIBs”)

Earnings per common share (Tabl

Earnings per common share (Tables)	6 Months Ended
	Sep. 30, 2019
Computation of Basic and Diluted Earnings Per Common Share	The following table sets forth the computation of basic and diluted earnings per common share for the six months ended September 30, 2018 and 2019: Six months ended September 30, 2018 2019 (in millions of yen) Net income: Net income attributable to MHFG common shareholders 285,270 212,984 Effect of dilutive securities — — Net income attributable to common shareholders after assumed conversions 285,270 212,984 Six months ended September 30, 2018 2019 (thousands of shares) Shares: Weighted average common shares outstanding 25,363,167 25,367,997 Effect of dilutive securities: Stock options and the common shares of MHFG under the stock compensation programs 4,790 2,093 Weighted average common shares after assumed conversions 25,367,957 25,370,090 Six months ended September 30, 2018 2019 (in yen) Earnings per common share: Basic net income per common share 11.25 8.40 Diluted net income per common share 11.25 8.40

Income taxes (Tables)

Income taxes (Tables)	6 Months Ended
	Sep. 30, 2019
Components of Income Tax Expense	The following table presents the components of Income tax expense for the six months ended September 30, 2018 and 2019: Six months ended 2018 2019 (in millions of yen) Current tax expense 114,666 88,437 Deferred tax expense (benefit) (28,961 ) (5,317 ) Total income tax expense 85,705 83,120
Detailed Amounts of Tax Effects of Items Recorded Directly in Equity	The preceding table does not reflect the tax effects of items recorded directly in Equity for the six months ended September 30, 2018 and 2019. The detailed amounts recorded directly in Equity are as follows: Six months ended 2018 2019 (in millions of yen) Net unrealized gains (losses) on available-for-sale Unrealized gains (losses) (11,292 ) 11,023 Less: reclassification adjustments (383 ) (9,192 ) Total (11,675 ) 1,831 Pension liability adjustments: Unrealized gains (losses) (97 ) (643 ) Less: reclassification adjustments (1,184 ) (937 ) Total (1,281 ) (1,580 ) Own credit risk adjustments: Unrealized gains (losses) 967 (43 ) Less: reclassification adjustments (9 ) (588 ) Total 958 (631 ) Total tax effect before allocation to noncontrolling interests (11,998 ) (380 )

Pension and other employee be_2

Pension and other employee benefit plans (Tables)	6 Months Ended
	Sep. 30, 2019
Components of Net Periodic Benefit Cost of Severance Indemnities and Pension Plans	The following table summarizes the components of net periodic benefit cost of the severance indemnities and pension plans of the MHFG Group for the six months ended September 30, 2018 and 2019: Six months ended September 30, 2018 2019 (in millions of yen) Service cost-benefits earned during the period 21,726 22,729 Interest costs on projected benefit obligations 3,331 2,666 Expected return on plan assets (19,124 ) (20,158 ) Amortization of prior service benefits 76 19 Amortization of net actuarial loss (gain) (3,942 ) (3,064 ) Special termination benefits 1,792 2,188 Net periodic benefit cost 3,859 4,380

Derivative financial instrume_2

Derivative financial instruments (Tables)	6 Months Ended
	Sep. 30, 2019
Summary of Notional and Fair Value Amounts of Derivative Instruments Outstanding	The following table summarizes the notional and fair value amounts of derivative instruments outstanding as of March 31, 2019 and September 30, 2019. The fair values of derivatives are presented on a gross basis, derivative receivables and payables are not offset. In addition, they are not offset against the amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral under master netting agreements in the consolidated balance sheets, or the table below. Fair value Derivative receivables (2) Derivative payables (2) March 31, 2019 Notional amount (1) Designated as hedges Not designated as hedges Designated as hedges Not designated as hedges (in billions of yen) Interest rate contracts 1,052,267 — 5,786 — 5,610 Foreign exchange contracts 166,383 — 1,959 — 1,758 Equity-related contracts 5,181 — 125 — 142 Credit-related contracts 2,939 — 18 — 17 Other contracts 438 — 16 — 14 Total 1,227,208 — 7,904 — 7,541 Fair value Derivative receivables (2) Derivative payables (2) September 30, 2019 Notional amount (1) Designated as hedges Not designated as hedges Designated as hedges Not designated as hedges (in billions of yen) Interest rate contracts 1,102,120 — 7,054 — 6,788 Foreign exchange contracts 170,816 — 2,342 — 2,202 Equity-related contracts 6,197 — 148 — 176 Credit-related contracts 2,923 — 21 — 25 Other contracts 425 — 16 — 15 Total 1,282,481 — 9,581 — 9,206 Notes: (1) Notional amount includes the sum of gross long and gross short third-party contracts. (2) Derivative receivables and payables are recorded in Trading account assets and Trading account liabilities, respectively.
Summary of Notional and Fair Value Amounts of Credit Derivatives	The following table summarizes the notional and fair value amounts of credit derivatives at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 Notional amount Fair value Notional amount Fair value (in billions of yen) Credit protection written: Investment grade 1,266 12 1,072 13 Non-investment 199 3 225 5 Total 1,465 15 1,297 18 Credit protection purchased 1,628 (14 ) 1,788 (22 ) Note: The rating scale is based upon either the external ratings or the internal ratings of the underlying reference credit. The lowest investment grade rating is considered to be BBB - non-investment Non-investment
Maximum Potential Amount of Future Payments for Credit Protection Written by Expiration Period	The following table shows the maximum potential amount of future payments for credit protection written by expiration period at March 31, 2019 and September 30, 2019: Maximum payout/Notional amount March 31, 2019 September 30, 2019 (in billions of yen) One year or less 326 293 After one year through five years 1,057 902 After five years 82 102 Total 1,465 1,297 Note: The maximum potential amount of future payments is the aggregate notional amount of the credit derivatives where the Group wrote the credit protection, and it has not been reduced by the effect of any amounts that the Group may possibly collect on the underlying assets and the related cash flows, nor netted against that of credit protection purchased.
Quantitative Information about Derivative Instruments with Credit-risk-related Contingent Features	The following table shows the quantitative information about derivative instruments with credit-risk-related contingent features at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in billions of yen) Aggregate fair value of derivative instruments with credit-risk-related contingent features in net liability positions 511 695 Collateral provided to counterparties in the normal course of business 489 679 Amount required to be posted as collateral or settled immediately if credit-risk-related contingent features were triggered 22 16
Not Designated as Hedging Instrument
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	The following table summarizes gains and losses on derivatives not designated or qualifying as hedges during the six months ended September 30, 2018 and 2019: Gains (losses) recorded in income 2018 2019 (in millions of yen) Interest rate contracts (75,324 ) 210,909 Foreign exchange contracts 26,706 (30,736 ) Equity-related contracts 20,432 (494 ) Credit-related contracts ( 1 (35 ) (3,546 ) Other contracts (785 ) (1,650 ) Total (29,006 ) 174,483 Notes: (1) Amounts include the net gains (losses) of ¥( 215 ( 426 )
Net Investment Hedging | Designated as Hedging Instrument
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	The following table summarizes gains and losses information related to net investment hedges for the six months ended September 30, 2018 and 2019: Gains (losses) recorded in other for six months ended September 30, 2018 2019 (in millions of yen) Financial instruments hedging foreign exchange risk 1,906 (1,044 ) Total 1,906 (1,044 ) Note: Related to the net investment hedges, gains (losses) of ¥ 186 million and ¥( 260 m illion were reclassified from Accumulated other comprehensive income to earnings for the six months ended September 30, 2018 and

Commitments and contingencies (

Commitments and contingencies (Tables)	6 Months Ended
	Sep. 30, 2019
Summary of Maximum Potential Amount of Future Payments under Guarantees	the MHFG Group is exposed to unlimited losses; therefore, the table shows the notional amounts of the contracts as a substitute for the maximum exposure. March 31, 2019 September 30, 2019 (in billions of yen) Performance guarantees 2,307 2,182 Guarantees on loans 289 246 Guarantees on securities 145 110 Other guarantees 2,324 2,291 Guarantees for the repayment of trust principal 65 63 Liabilities of trust accounts 362 376 Derivative financial instruments 14,170 19,421
Summary of Contractual Amounts with Regard to Undrawn Commitments	The table below summarizes the contractual amounts with regard to these undrawn commitments at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in billions of yen) Commitments to extend credit (Note) 76,857 78,075 Commercial letters of credit 778 818 Total 77,635 78,893 Note: Commitments to extend credit include commitments to invest in securities.
Schedule of Balance Sheet Information Related to operating lease	The following table presents the consolidated balance sheet information related to operating leases as of September 30, 2019: As of September 30, 2019 (in millions of yen, except for ROU assets (Note) 647,185 Lease liabilities (Note) 656,409 Weighted average: Remaining lease term 15.8years Discount rate 0.55% Note: ROU assets and lease liabilities are included in Other assets and Other liabilities, respectively, on the consolidated balance sheet s
Schedule of operating lease cost and supplemental cash flow information	The following table presents lease cost and supplemental information related to operating leases for the six months ended September 30, 2019: Six months ended September 30, (in millions of yen) Lease cost (Note) 62,003 ROU assets obtained in exchange for new lease liabilities 45,904 Operating cash flows 51,120 Note: Lease cost for operating leases are included in Occupancy expenses on the consolidated statement s The Group’s variable lease costs and costs for leases with terms of twelve months or less are not significant.
Future Minimum Lease Payments for Capitalized Leases and Rental Payments for Operating Leases	The following table shows future lease payments under operating leases as of September 30, 2019: As of September 30, 2019 (in millions of yen) Fiscal year ending March 31: 2020 (excluding six months ended September 30, 2019) 49,182 2021 84,578 2022 64,138 2023 52,167 2024 46,829 2025 and thereafter 386,291 Total lease payments 683,185 Amount representing interest 26,776 Total lease liabilities for operating leases 656,409
Performance guarantees, Guarantees on loans, Guarantees on securities and Other guarantees
Summary of Maximum Potential Amount of Future Payments under Guarantees	The table below presents the maximum potential amount of future payments of performance guarantees, guarantees on loans, guarantees on securities and other guarantees classified based on internal ratings at March 31, 2019 and September 30, 2019: March 31, 2019 September 30, 2019 (in billions of yen) Investment grade 4,124 3,909 Non-investment 941 920 Total 5,065 4,829 Note: Investment grade in the internal rating scale generally corresponds to BBB-

Variable interest entities an_2

Variable interest entities and securitizations (Tables)	6 Months Ended
	Sep. 30, 2019
Schedule of Variable Interest Entities	The table below shows the consolidated assets of the Group’s consolidated VIEs as well as total assets and maximum exposure to loss for its significant unconsolidated VIEs, as of March 31, 2019 and September 30, 2019: Consolidated VIEs Significant unconsolidated VIEs March 31, 2019 Consolidated assets Total assets Maximum (in billions of yen) Asset-backed commercial paper/loan programs 2,249 — — Asset-backed securitizations 571 70 8 Investments in securitization products 372 — — Investment funds 2,836 1,280 410 Trust arrangements and other 20 — — Total 6,048 1,350 418 Consolidated VIEs Significant unconsolidated VIEs September 30, 2019 Consolidated assets Total assets Maximum exposure to (in billions of yen) Asset-backed commercial paper/loan programs 2,325 — — Asset-backed securitizations 544 70 9 Investments in securitization products 371 — — Investment funds 2,680 1,600 476 Trust arrangements and other 19 — — Total 5,939 1,670 485
Unconsolidated VIEs
Schedule of Variable Interest Entities	The tables below present the carrying amounts and classification of assets and liabilities on the MHFG Group’s balance sheets that relate to its variable interests in significant unconsolidated VIEs, as of March 31, 2019 and September 30, 2019: Assets on balance sheets related to unconsolidated VIEs: March 31, 2019 September 30, 2019 (in billions of yen) Trading account assets 104 107 Investments 168 171 Loans 71 122 Total 343 400 Liabilities on balance sheets and maximum exposure to loss related to unconsolidated VIEs: March 31, 2019 September 30, 2019 (in billions of yen) Payables under securities lending transactions 47 47 Trading account liabilities 1 1 Total 48 48 Maximum exposure to loss (Note) 418 485 Note: This represents the maximum amount the Group could possibly be required to record in its consolidated statements of income associated with on-balance-sheet off-balance-sheet

Noninterest income (Tables)

Noninterest income (Tables)	6 Months Ended
	Sep. 30, 2019
Summary of Noninterest Income	Details of Noninterest income for the six months ended September 30, 2018 and 2019 are as follows: Six months ended September 30, 2018 2019 (in millions of yen) Fee and commission income: Securities-related business (1) 79,138 64,498 Deposits and lending business (2) 70,647 76,179 Remittance business (1) 55,078 56,075 Asset management business (1) 49,818 48,291 Trust related business (1) 57,372 56,459 Agency business (1) 19,509 15,152 Guarantee related business (3) 14,234 13,898 Fees for other customer services (1) 67,931 73,440 Total Fee and commission income 413,727 403,992 Foreign exchange gains (losses)—net (3) 44,718 27,923 Trading account gains (losses)—net (2) 64,956 395,405 Investment gains (losses)—net: Debt securities (3) 2,485 31,092 Equity securities (3) 306,788 (126,648 ) Equity in earnings (losses) of equity method investees—net (3) 22,627 22,066 Gains on disposal of premises and equipment (3) 4,305 1,693 Other noninterest income (2) 48,950 34,839 Total 908,556 790,362 Notes: (1) These amounts are revenues from contracts within the scope of ASC 606, “Revenue from contracts with customers” (“ASC 606”). (2) Part of these amounts are considered to be revenues from contracts that are within the scope of ASC 606. (3) These amounts are revenues from contracts that do not meet the scope of ASC 606.

Fair value (Tables)

Fair value (Tables)	6 Months Ended
	Sep. 30, 2019
Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis, Including Fair Value Option Elected	Items measured at fair value on a recurring basis Assets and liabilities measured at fair value on a recurring basis at March 31, 2019 and September 30, 2019, including those for which the MHFG Group has elected the fair value option, are summarized below: March 31, 2019 Level 1 Level 2 Level 3 Assets/ Liabilities measured at (in billions of yen) Assets: Trading securities (1) Japanese government bonds 1,829 33 — 1,862 Japanese local government bonds — 134 — 134 U.S. Treasury bonds and federal agency securities 1,069 138 — 1,207 Other foreign government bonds 2,417 553 — 2,970 Agency mortgage-backed securities — 1,041 — 1,041 Residential mortgage-backed securities — — 11 11 Certificates of deposit and commercial paper — 1,047 — 1,047 Corporate bonds and other (2) 36 1,806 1,044 2,886 Equity securities 1,297 — 28 1,325 Trading securities measured at net asset value (3) 631 Derivative financial instruments: Interest rate contracts 36 5,729 21 5,786 Foreign exchange contracts 9 1,927 23 1,959 Equity-related contracts 58 63 4 125 Credit-related contracts — 16 2 18 Other contracts 2 4 10 16 Available-for-sale Japanese government bonds 10,902 995 — 11,897 Japanese local government bonds — 210 — 210 U.S. Treasury bonds and federal agency securities 1,009 — — 1,009 Other foreign government bonds 456 886 — 1,342 Agency mortgage-backed securities — 544 — 544 Residential mortgage-backed securities — 61 40 101 Commercial mortgage-backed securities — — 500 500 Japanese corporate bonds and other debt securities — 1,629 120 1,749 Foreign corporate bonds and other debt securities — 678 103 781 Equity securities: Equity securities with readily determinable fair values 3,633 135 — 3,768 Equity securities measured at net asset value (3) 53 Other investments — — 35 35 Total assets measured at fair value on a recurring basis 22,753 17,629 1,941 43,007 Liabilities: Trading securities sold, not yet purchased 2,380 199 1 2,580 Derivative financial instruments: Interest rate contracts 38 5,564 8 5,610 Foreign exchange contracts 11 1,746 1 1,758 Equity-related contracts 82 51 9 142 Credit-related contracts — 16 1 17 Other contracts 1 4 9 14 Long-term debt (4) — 1,778 655 2,433 Total liabilities measured at fair value on a recurring basis 2,512 9,358 684 12,554 September 30, 2019 Level 1 Level 2 Level 3 Assets/ Liabilities measured at fair value (in billions of yen) Assets: Trading securities (1) : Japanese government bonds 2,506 28 — 2,534 Japanese local government bonds — 123 — 123 U.S. Treasury bonds and federal agency securities 2,089 223 — 2,312 Other foreign government bonds 1,638 625 — 2,263 Agency mortgage-backed securities — 1,962 — 1,962 Residential mortgage-backed securities — — 10 10 Certificates of deposit and commercial paper — 1,316 — 1,316 Corporate bonds and other (2) 41 1,559 1,137 2,737 Equity securities 1,081 — 30 1,111 Trading securities measured at net asset value (3) 1,001 Derivative financial instruments: Interest rate contracts 49 6,997 8 7,054 Foreign exchange contracts 7 2,324 11 2,342 Equity-related contracts 61 75 12 148 Credit-related contracts — 18 3 21 Other contracts 1 5 10 16 Available-for-sale securities: Japanese government bonds 10,600 827 — 11,427 Japanese local government bonds — 235 — 235 U.S. Treasury bonds and federal agency securities 1,001 — — 1,001 Other foreign government bonds 421 911 — 1,332 Agency mortgage-backed securities — 512 — 512 Residential mortgage-backed securities — 54 33 87 Commercial mortgage-backed securities — — 549 549 Japanese corporate bonds and other debt securities — 1,634 169 1,803 Foreign corporate bonds and other debt securities — 611 133 744 Equity securities : Equity securities with readily determinable fair values 3,350 123 — 3,473 Equity securities measured at net asset value (3) 61 Other investments — — 36 36 Total assets measured at fair value on a recurring basis 22,845 20,162 2,141 46,210 Liabilities: Trading securities sold, not yet purchased 2,571 196 — 2,767 Derivative financial instruments: Interest rate contracts 49 6,736 3 6,788 Foreign exchange contracts 7 2,194 1 2,202 Equity-related contracts 104 53 19 176 Credit-related contracts — 23 2 25 Other contracts 1 5 9 15 Long-term debt (4) — 2,016 646 2,662 Total liabilities measured at fair value on a recurring basis 2,732 11,223 680 14,635 Notes: (1) Trading securities include foreign currency denominated securities for which the MHFG Group elected the fair value option. (2) The amount includes CLO and convertible bonds, which are classified in Level 3. (3) In accordance with ASC 820, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented for these classes of assets are intended to permit the reconciliation of the fair value hierarchy to the amounts presented in the statements of financial position. The amounts of unfunded commitments related to these investments at March 31, 2019 and September 30, 2019 were ¥37 billion and ¥41 billion, respectively. (4) Amounts represent items for which the Group elected the fair value option or for which it applied the practicability exception.
Reconciliation for All Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)	The following table presents a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the six months ended September 30, 2018 and 2019: Six months ended September 30, 2018 April 1, 2018 Gains (losses) in Earnings Gains (losses) OCI Transfers into Level 3 Transfers out of Level 3 Purchases Sales Issuances Settle- ments September 30, 2018 Change in unrealized gains (losses) still held (6) (in billions of yen) Assets: Trading securities: Residential mortgage-backed securities 12 — (2) — — — — — — — 12 — Corporate bonds and other 1,013 31 (2) — — — 457 (242 ) — (154 ) 1,105 35 Equity securities 23 2 (2) — — — 5 (1 ) — — 29 — Derivative financial instruments, net (1) Interest rate contracts 21 1 (2) — — — — — — 1 23 2 Foreign exchange contracts 12 15 (2) — — — — — — (2 ) 25 17 Equity-related contracts 4 (4 ) (2) — — — — — — 14 14 — Credit-related contracts 1 (3 ) (2) — — — — — — 2 — — Available-for-sale Residential mortgage-backed securities 54 — (3) — (4) — — — — — (8 ) 46 — Commercial mortgage-backed securities 441 — (3) — (4) — — 57 (28 ) — (1 ) 469 — Japanese corporate bonds and other debt securities 163 10 (3) (8 ) (4) — — 7 (7 ) — (9 ) 156 10 Foreign corporate bonds and other debt securities 80 — (3) — (4) 61 — 4 — — — 145 — Other investments 38 1 (3) — — — 13 — — (11 ) 41 2 Liabilities: Trading securities sold, not yet purchased 4 1 (2) — — — (30 ) 29 — — 2 — Long-term debt 561 2 (5) 3 (4) 2 — — — 85 (31 ) 612 4 Six months ended September 30, 2019 April 1, 2019 Gains (losses) in Earnings Gains (losses) in OCI Transfers into Level 3 Transfers out of Level 3 Purchases Sales Issuances Settle- ments September 30, 2019 Change in unrealized gains (losses) still held (6) (in billions of yen) Assets: Trading securities: Residential mortgage-backed securities 11 — (2) — — — — — — (1 ) 10 — Corporate bonds and other 1,044 (15 ) (2) — — — 338 (105 ) — (125 ) 1,137 (14 ) Equity securities 28 2 (2) — — — 1 — — (1 ) 30 — Derivative financial instruments, net (1) Interest rate contracts 13 (9 ) (2) — — — — — — 1 5 (8 ) Foreign exchange contracts 22 (10 ) (2) — — — — — — (2 ) 10 (9 ) Equity-related contracts (5 ) 1 (2) — — — — — — (3 ) (7 ) 2 Credit-related contracts 1 — (2) — — — — — — — 1 — Other contracts 1 — (2) — — — — — — — 1 — Available-for-sale Residential mortgage-backed securities 40 — (3) — (4) — — — — — (7 ) 33 — Commercial mortgage-backed securities 500 — (3) 1 (4) — — 89 (35 ) — (6 ) 549 — Japanese corporate bonds and other debt securities 120 1 (3) 4 (4) — — 97 — — (53 ) 169 — Foreign corporate bonds and other debt securities 103 — (3) (5 ) (4) — — 38 — — (3 ) 133 — Other investments 35 1 (3) — — — 10 — — (10 ) 36 2 Liabilities: Trading securities sold, not yet purchased 1 — (2) — — — (9 ) 8 — — — — Long-term debt 655 (6 ) (5) — (4) 17 (6 ) — — 108 (134 ) 646 (10 ) Notes: (1) Total Level 3 derivative exposures have been netted on the table for presentation purposes only. (2) Gains (losses) in Earnings are reported in Trading account gains (losses)—net, Foreign exchange gains (losses)—net or Other noninterest income (expenses). (3) Gains (losses) in Earnings are reported in Investment gains (losses)—net. (4) Gains (losses) in OCI are reported in Other comprehensive income (loss). (5) Gains (losses) in Earnings are reported in Other noninterest income (expenses). (6) Amounts represent total gains or losses recognized in earnings during the period. These gains or losses were attributable to the change in fair value relating to assets and liabilities classified as Level 3 that were still held at September 30, 2018 and 2019.
Quantitative Information about Significant Unobservable Inputs Related to Material Classes of Level 3 Assets and Liabilities	The following table presents information about significant unobservable inputs related to the MHFG Group’s material classes of Level 3 assets and liabilities at March 31, 2019 and September 30, 2019: March 31, 2019 Products/Instruments Fair value Principal valuation technique Unobservable inputs Range of input values Weighted average (5) (in billions of yen, except for percentages and basis points) Trading securities and Available-for-sale Residential mortgage-backed securities 51 Discounted cash flow Price-based Prepayment rate Default rate Recovery rate Discount margin 4% - 19% 0% - 1% 100% - 100% 18bps - 170bps 8% 0% 100% 51bps Commercial mortgage-backed securities 500 Discounted cash flow Price-based Discount margin 9bps - 161bps 24bps Corporate bonds and other debt securities 1,267 Discounted cash flow Price-based Prepayment rate (1) Default rate (1) Recovery rate (1) Discount margin (1) Discount margin (2) 22% - 22% 2% - 2% 69% - 69% 48bps - 1,173bps 4 22% 2% 69% 134bps 295bps Derivative financial instruments, net: Interest rate contracts 13 Internal valuation model (3) IR – IR correlation Default rate (4) 23% - 100% 0% - 63% Foreign exchange contracts 22 Internal valuation model (3) FX – IR correlation FX – FX correlation Default rate (4) 9% - 55% 63% - 63% 0% - 63% Equity-related contracts (5 ) Internal valuation model (3) Equity – IR correlation Equity correlation Equity volatility 25% - 25% 40% - 100% 5% - 36% Credit-related contracts 1 Internal valuation model (3) Default rate Credit correlation 0% - 5% 29% - 100% Long-term debt 655 Internal valuation model (3) IR – IR correlation FX – IR correlation FX – FX correlation Equity – IR correlation Equity – FX correlation Equity correlation Equity volatility Default rate Credit correlation 23% - 100% 9% - 55% 63% - 63% 25% - 25% 55% - 88% 12% - 100% 5% - 49% 0% - 4% 20% - 100% September 30, 2019 Products/Instruments Fair value Principal valuation technique Unobservable inputs Range of input values Weighted average (5) (in billions of yen, except for percentages and basis points) Trading securities and Available-for-sale Residential mortgage-backed securities 43 Discounted cash flow Price-based Prepayment rate Default rate Recovery rate Discount margin 4% -18% 0% - 1% 100% -100% 10bps -170bps 7% 0% 100% 51bps Commercial mortgage-backed securities 549 Discounted cash flow Price-based Discount margin 7bps - 161bps 23bps Corporate bonds and other debt securities 1,439 Discounted cash flow Price-based Prepayment rate (1) Default rate (1) Recovery rate (1) Discount margin (1) Discount margin (2) 16% - 17% 0% - 2% 40% - 70% 41bps - 1,193bps 2bps - 630bps 16% 2% 69% 127bps 51bps Derivative financial instruments, net: Interest rate contracts 5 Internal valuation model (3) IR – IR correlation Default rate (4) 23% - 100% 0% - 63% Foreign exchange contracts 10 Internal valuation model (3) FX – IR correlation FX – FX correlation Default rate (4) -19% - 55% 61% - 61% 0% - 63% Equity-related contracts (7 ) Internal valuation model (3) Equity – IR correlation Equity – FX correlation Equity Equity volatility 25% - 25% 70% - 70% 29% - 100% 6% Credit-related contracts 1 Internal valuation model (3) Default rate Credit correlation 0% - 9% 30% - 100% Long-term debt 646 Internal valuation model (3) IR – IR correlation FX – IR correlation FX – FX correlation Equity – IR correlation Equity – FX correlation Equity correlation Equity volatility Default rate Credit correlation 23% - 100% 24% - 55% 61% - 61% 25% - 25% 0% - 70% 16% - 100% 6% - 61% 0% - 4% 15% - 100% Notes: (1) These inputs are mainly used for determining the fair values of securitization products such as CDO, CLO and ABS, other than RMBS and CMBS. (2) This input is mainly used for determining the fair values of Japanese corporate bonds and foreign corporate bonds. (3) Internal valuation model includes discounted cash flow models and the Black-Scholes option pricing model. (4) This input represents the counterparty default rate derived from the MHFG Group’s own internal credit analyses. (5) Weighted averages are calculated by weighting each input by the relative fair value of the respective financial instruments. IR = Interest rate FX = Foreign exchange
Summary of Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis	The following table shows the fair value hierarchy for these items as of March 31, 2019 and September 30, 2019: March 31, 2019 Total Level 1 Level 2 Level 3 Aggregate cost (in billions of yen) Assets: Loans 125 — 41 84 177 Loans held-for-sale 3 — 3 — 3 Equity securities (without readily determinable fair values) 1 — — 1 1 Other investments 98 98 — — 104 Premises and equipment—net 9 — 4 5 34 Intangible assets — — — — 1 Total assets measured at fair value on a nonrecurring basis 236 98 48 90 320 September 30, 2019 Total Level 1 Level 2 Level 3 Aggregate cost (in billions of yen) Assets: Loans 128 — 8 120 171 Loans held-for-sale 62 — 62 — 64 Equity securities (without readily determinable fair values) 8 — — 8 2 Other investments 3 3 — — 5 Premises and equipment—net 1 — 1 — 5 Total assets measured at fair value on a nonrecurring basis 202 3 71 128 247 Note: The fair values may not be current as of the dates indicated, but rather as of the date the fair value change occurred. Accordingly, the carrying values may not equal current fair value.
Carrying Amounts and Fair Values of Certain Financial Instruments, Excluding Financial Instruments Carried at Fair Value on a Recurring Basis and Those outside Scope of ASC 825	The following table shows the carrying amounts and fair values at March 31, 2019 and September 30, 2019, of certain financial instruments, excluding financial instruments which are carried at fair value on a recurring basis and those outside the scope of ASC 825 such as equity method investments as defined in ASC 323, “Investments-Equity Method and Joint Ventures” (“ASC 323”) and lease contracts as defined in ASC 840, “Leases” (“ASC 840”): March 31, 2019 Carrying amount Estimated fair value Total Level 1 Level 2 Level 3 (in billions of yen) Financial assets: Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions 62,012 62,012 873 61,139 — Investments 1,604 1,609 1,140 469 — Loans, net of allowance for loan losses (Note) 82,382 83,490 — — 83,490 Financial liabilities: Noninterest-bearing deposits, call money and funds purchased, and payables under repurchase agreements and securities lending transactions 44,918 44,918 24,983 19,935 — Interest-bearing deposits 112,658 112,655 55,542 57,113 — Due to trust accounts 312 312 — 312 — Other short-term borrowings 1,995 1,995 — 1,995 — Long-term debt 9,096 9,178 — 8,336 842 September 30, 2019 Carrying amount Estimated fair value Total Level 1 Level 2 Level 3 (in billions of yen) Financial assets: Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions 61,739 61,739 1,011 60,728 — Investments 1,064 1,075 660 415 — Loans, net of allowance for loan losses (Note) 83,443 84,611 — — 84,611 Financial liabilities: Noninterest-bearing deposits, call money and funds purchased, and payables under repurchase agreements and securities lending transactions 48,827 48,827 26,954 21,873 — Interest-bearing deposits 112,303 112,312 55,404 56,908 — Due to trust accounts 320 320 — 320 — Other short-term borrowings 1,608 1,608 — 1,608 — Long-term debt 7,774 7,923 — 7,071 852 Note: Loans, net of allowance for loan losses include items measured at fair value on a nonrecurring basis.

Offsetting of financial asset_2

Offsetting of financial assets and financial liabilities (Tables)	6 Months Ended
	Sep. 30, 2019
Information of Offsetting of Financial Assets and Financial Liabilities	The following table provides information about the offsetting of financial assets and financial liabilities at March 31, 2019 and September 30, 2019. The table includes derivatives, repurchase and resale agreements, and securities lending and borrowing transactions that are subject to enforceable master netting arrangements or similar agreements irrespective of whether or not they are offset on the Group’s consolidated balance sheets. Amounts not offset on the balance sheet (3) Gross amounts recognized Gross amounts offset on the balance sheet Net amounts presented on the balance sheet (2) Financial instruments (4) Cash collateral Net amounts (in billions of yen) March 31, 2019 Assets (1) Derivatives 7,403 — 7,403 (5,903 ) (528 ) 972 Receivables under resale agreements 12,589 — 12,589 (12,579 ) — 10 Receivables under securities borrowing transactions 1,921 — 1,921 (1,894 ) — 27 Total 21,913 — 21,913 (20,376 ) (528 ) 1,009 Liabilities (1) Derivatives 6,978 — 6,978 (5,766 ) (769 ) 443 Payables under repurchase agreements 14,312 — 14,312 (14,309 ) — 3 Payables under securities lending transactions 932 — 932 (931 ) — 1 Total 22,222 — 22,222 (21,006 ) (769 ) 447 September 30, 2019 Assets (1) Derivatives 9,026 — 9,026 (7,372 ) (466 ) 1,188 Receivables under resale agreements 13,401 — 13,401 (13,386 ) — 15 Receivables under securities borrowing transactions 2,316 — 2,316 (2,265 ) — 51 Total 24,743 — 24,743 (23,023 ) (466 ) 1,254 Liabilities (1) : Derivatives 8,545 — 8,545 (7,225 ) (893 ) 427 Payables under repurchase agreements 16,837 — 16,837 (16,798 ) — 39 Payables under securities lending transactions 1,024 — 1,024 (1,020 ) — 4 Total 26,406 — 26,406 (25,043 ) (893 ) 470 Notes: (1) Amounts relating to master netting arrangements or similar agreements where the MHFG Group does not have the legal right of set-off over-the-counter OTC-cleared (2) Derivative assets and liabilities are recorded in Trading account assets and Trading account liabilities, respectively. (3) Amounts do not exceed the net amounts presented on the balance sheet and do not include the effect of overcollateralization, where it exists. (4) For derivatives, amounts include derivative assets or liabilities and securities collateral that are eligible for offsetting under enforceable master netting arrangements or similar agreements.

Repurchase agreements and sec_2

Repurchase agreements and securities lending transactions accounted for as secured borrowings (Tables)	6 Months Ended
	Sep. 30, 2019
Gross Amounts of Liabilities by Remaining Contractual Maturity	The following table shows the gross amounts of liabilities associated with repurchase agreements and securities lending transactions, by remaining contractual maturity at March 31, 2019 and September 30, 2019: Overnight and continuous Up to 30 days 31-90 Greater than 90 days Total (in billions of yen) March 31, 2019 Repurchase agreements 2,596 8,537 2,403 1,104 14,640 Securities lending transactions 1,012 473 — 313 1,798 Total 3,608 9,010 2,403 1,417 16,438 September 30, 2019 Repurchase agreements 6,727 6,976 1,858 1,779 17,340 Securities lending transactions 807 660 110 280 1,857 Total 7,534 7,636 1,968 2,059 19,197
Gross Amounts of Liabilities by Class of Underlying Collateral	The following table shows the gross amounts of liabilities associated with repurchase agreements and securities lending transactions, by class of underlying collateral at March 31, 2019 and September 30, 2019: Repurchase agreements Securities lending transactions (in billions of yen) March 31, 2019 Japanese government bonds and Japanese local government bonds 2,118 430 Foreign government bonds and foreign agency mortgage-backed securities 11,613 396 Commercial paper and corporate bonds 223 52 Equity securities 492 902 Other 194 18 Total (Note) 14,640 1,798 September 30, 2019 Japanese government bonds and Japanese local government bonds 3,097 471 Foreign government bonds and foreign agency mortgage-backed securities 13,272 597 Commercial paper and corporate bonds 268 52 Equity securities 495 720 Other 208 17 Total (Note) 17,340 1,857 Note: Amounts exceeded the gross amounts recognized in Note 18 “Offsetting of financial assets and financial liabilities” by ¥1,194 billion and ¥1,336 set-off

Business segment information (T

Business segment information (Tables)	6 Months Ended
	Sep. 30, 2019
Reportable Segment Information Derived from Internal Management Reporting Systems, on Basis of Japanese GAAP	The reportable segment information, set forth below, is derived from the internal management reporting systems used by management to measure the performance of the Group’s operating segments. Management measures the performance of each of the operating segments in accordance with internal managerial accounting rules and practices. In addition, the format and information are presented primarily on the basis of Japanese GAAP. Therefore, they are not consistent with the consolidated financial statements prepared in accordance with U.S. GAAP. A reconciliation is provided for the total amount of all business segments’ “Net business profits (losses) + Net gains (losses) related to ETFs and others” with income before income tax expense under U.S. GAAP, and the total amount of all business segments’ “Fixed assets” with the total amount of Premises and equipment—net, Goodwill, Intangible assets, and ROU assets related to operating leases included in Other assets reported under U.S. GAAP. “Fixed assets” pertaining to MHBK, MHTB , . MHFG (Consolidated) Six months ended (5) Retail & Business Banking Company Corporate & Institutional Company Global Corporate Company Global Markets Company Asset Management Company Others (4) Total (in billions of yen) Gross profits + Net gains (losses) related to ETFs and others (1) 345.0 223.1 190.3 237.7 25.0 30.4 1,051.5 General and administrative expenses (2) 360.0 103.5 115.6 105.6 13.9 24.1 722.7 Equity in earnings (losses) of equity method investees — net 14.4 0.6 2.8 — 0.6 1.0 19.4 Amortization of goodwill and others 0.2 0.2 0.2 1.2 4.0 1.0 6.8 Others — — — — — (10.4 ) (10.4 ) Net business profits (losses) (3) (0.8 ) 120.0 77.3 130.9 7.7 (4.1 ) 331.0 MHFG (Consolidated) Six months ended Retail & Business Banking Company Corporate & Institutional Company Global Corporate Company Global Markets Company Asset Management Company Others (4) Total (in billions of yen) Gross profits + Net gains (losses) related to ETFs and others (1) 322.3 221.9 208.0 231.5 23.2 15.9 1,022.8 General and administrative expenses (2) 328.0 104.3 120.7 103.4 14.4 17.6 688.4 Equity in earnings (losses) of equity method investees — net 6.7 1.1 6.0 — 0.6 4.7 19.1 Amortization of goodwill and others 0.2 0.2 0.2 1.2 3.9 1.0 6.7 Others — — — — — (5.9 ) (5.9 ) Net business profits (losses) (3) 0.8 118.5 93.1 126.9 5.5 (3.9 ) 340.9 Fixed assets (6) 491.2 214.9 173.3 91.9 0.1 730.2 1,701.6 Notes: (1) “Gross profits + Net gains (losses) related to ETFs and others” is reported instead of sales reported by general corporations. Gross profits is defined as the sum of net interest income, fiduciary income, net fee and commission income, net trading income and net other operating income. Net gains (losses) related to ETFs and others consist of net gains (losses) on ETFs held by MHBK and MHTB on their non-consolidated basis (losses) related to ETFs and others amounted to ¥39.9 billion and ¥(8.0) billion, respectively, of which ¥33.7 billion and ¥(11.2) billion , respectively. (2) “General and administrative expenses” excludes non-recurring losses. (3) Net business profits (losses) is used in Japan as a measure of the profitability of core banking operations and is defined as gross profits (as defined above) less general and administrative expenses plus equity in earnings (losses) of equity method investees—net and others. Measurement of net business profits (losses) is required for regulatory reporting to the Financial Services Agency of Japan. (4) “Others” includes the following items: • profits and expenses pertaining to consolidated subsidiaries that are not subject to allocation; • consolidating adjustments, including eliminating internal transaction between each segment; • Equity in earnings (losses) of equity method investees-net • profits and losses pertaining to derivative transactions that reflect the counterparty risk of the individual parties and other factors in determining fair market value. ( 5 The MHFG Group adopted certain enhancements, which were not significant individually or in the aggregate, to the Group’s segment allocation methods under internal managerial accounting rules and practices, and accordingly, the figures for the six months ended September 30, 2018 have been restated to reflect these current period enhancements. Furthermore, income and expenses of foreign branches of MHBK and foreign subsidiaries with functional currencies other than Japanese Yen have been translated for purposes of segment reporting using the budgeted foreign currency rates. Prior period comparative amounts for such foreign currency income and expenses have been translated using current period budgeted foreign currency rates. ( 6 “Fixed assets” is presented based on Japanese GAAP and corresponds to the total amount of the following U.S. GAAP accounts: Premises and equipment—net, Goodwill, Intangible assets, and ROU assets related to operating leases included in Other assets. The above table does not include other asset amounts because “Fixed assets” is the only balance sheet metric that management uses when evaluating and making decisions pertaining to the operating segments. “Fixed assets” has been allocated to each segment starting in the fiscal year ended March 31, 2019 to enhance management’s analysis of the Group’s operations. “Others” in “Fixed assets” includes assets of headquarters that have not been allocated to each segment, “Fixed assets” pertaining to consolidated subsidiaries that are not subject to allocation, consolidating adjustments, and others. Certain “Fixed assets” expenses have been allocated to each segment using reasonable allocation criteria.
Reconciliation of Total Net Business Profits under Internal Management Reporting Systems to Income Before Income Tax Expense on Consolidated Statements of Income	A reconciliation of “Net business profits (losses) + Net gains (losses) related to ETFs and others” for the six months ended September 30, 2018 and 2019 presented above to income before income tax expense shown on the consolidated statements of income and a reconciliation of “Fixed assets” for the six months ended September 30, 2019 to the total amount of Premises and equipment—net, Goodwill, and Intangible assets are as follows: Six months ended September 30, 2018 2019 (in billions of yen) Net business profits (losses) + Net gains (losses) related to ETFs and others 331.0 340.9 Adjustment to reconcile management reporting to Japanese GAAP: General and administrative expenses (non-recurring 12.0 24.5 Expenses related to portfolio problems (including reversal of (provision for) general reserve for losses on loans) (20.8 ) (19.1 ) Gains on reversal of reserves for possible losses on loans, and others 50.6 7.9 Net gains (losses) related to stocks—Net gains (losses) related to ETFs and others 110.1 55.4 Net extraordinary gains 6.7 (5.0 ) Others (16.0 ) (13.1 ) Income before income tax expense under Japanese GAAP 473.6 391.5 Adjustment to reconcile Japanese GAAP to U.S. GAAP: Derivative financial instruments and hedging activities (75.4 ) 105.0 Investments 92.1 (163.9 ) Loans (4.2 ) — Allowances for loan losses and off-balance-sheet (10.5 ) 0.5 Premises and equipment (77.3 ) (51.5 ) Land revaluation 1.5 0.5 Business combinations 7.5 4.1 Pension liabilities (19.8 ) (27.3 ) Consolidation of variable interest entities 43.9 40.3 Foreign currency translation (8.5 ) 14.3 Others (5.3 ) (3.0 ) Income before income tax expense under U.S. GAAP 417.6 310.5
Reconciliation of Assets from Segment to Consolidated [Table Text Block]	September 30, 2019 (in billions of yen) Fixed assets 1,701.6 U.S. GAAP adjustments 964.5 Premises and equipment—net, Goodwill, Intangible assets, and ROU assets related to operating leases included in Other assets 2,666.1 Note: The U.S. GAAP adjustments are primarily comprised of GAAP differences mainly from ROU assets related to operating leases not recognized under Japanese GAAP; internally developed software, which was impaired under Japanese GAAP; land, which was revalued under Japanese GAAP; and the consolidation of certain variable interest entities, which are not consolidated under Japanese GAAP.

Recently Issued Accounting Pr_2

Recently Issued Accounting Pronouncements - Additional Information (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019	Apr. 01, 2018	Mar. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating assets, right of use assets	[1]	¥ 647,185
Operating assets, lease liabilities	[1]	¥ 656,409
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principles, net of tax			¥ 1,052		¥ 1,537,322
Accumulated Other Comprehensive Income
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principles, net of tax	[2]		¥ (1,052)		(1,535,142)
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating assets, right of use assets					600,000
Operating assets, lease liabilities					¥ 600,000
ASU No.2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity securities				¥ 5,000
ASU No.2016-01 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principles, net of tax				1,545,000
ASU No.2016-01 | Retained Earnings | Equity Method Investments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principles, net of tax				1,530,000
ASU No.2016-01 | Accumulated Other Comprehensive Income
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principles, net of tax				¥ 10,000
[1]	ROU assets and lease liabilities were recognized in connection with the adoption of ASU No.2016-02 on April 1, 2019. See Note 1 “Basis of presentation” and Note 2 “Recently issued accounting pronouncements” for further information.
[2]	See Note 2 “Recently issued accounting pronouncements” for further details of the cumulative-effect adjustment for AOCI.

Investments (Amortized Cost, Gr

Investments (Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value of Available-for-Sale and Held-to-Maturity Securities) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Schedule of Investments [Line Items]
Amortized cost, available-for-sale securities		¥ 17,643,933	¥ 18,094,439
Gross unrealized gains, available-for-sale securities		54,114	45,923
Gross unrealized losses, available-for-sale securities		7,464	6,446
Fair value, available-for-sale securities		17,690,583	18,133,916
Amortized cost, held-to-maturity securities		1,064,376	1,604,104
Gross unrealized gains, held-to-maturity securities		20,200	19,907
Gross unrealized losses, held-to-maturity securities		9,767	14,423
Total		1,074,809	1,609,588
Debt securities | Japanese government bonds
Schedule of Investments [Line Items]
Amortized cost, available-for-sale securities		11,419,982	11,888,510
Gross unrealized gains, available-for-sale securities		11,130	11,259
Gross unrealized losses, available-for-sale securities		4,247	2,998
Fair value, available-for-sale securities		11,426,865	11,896,771
Amortized cost, held-to-maturity securities		639,913	1,119,899
Gross unrealized gains, held-to-maturity securities		20,198	19,907
Total		660,111	1,139,806
Debt securities | Japanese local government bonds
Schedule of Investments [Line Items]
Amortized cost, available-for-sale securities		234,345	208,308
Gross unrealized gains, available-for-sale securities		986	1,671
Gross unrealized losses, available-for-sale securities		169	87
Fair value, available-for-sale securities		235,162	209,892
Debt securities | U.S. Treasury bonds and federal agency securities
Schedule of Investments [Line Items]
Amortized cost, available-for-sale securities		1,000,684	1,008,903
Gross unrealized gains, available-for-sale securities		831	644
Gross unrealized losses, available-for-sale securities		430	231
Fair value, available-for-sale securities		1,001,085	1,009,316
Debt securities | Other foreign government bonds
Schedule of Investments [Line Items]
Amortized cost, available-for-sale securities		1,331,208	1,341,564
Gross unrealized gains, available-for-sale securities		1,576	758
Gross unrealized losses, available-for-sale securities		292	455
Fair value, available-for-sale securities		1,332,492	1,341,867
Debt securities | Agency mortgage-backed securities
Schedule of Investments [Line Items]
Amortized cost, available-for-sale securities	[1]	495,503	530,540
Gross unrealized gains, available-for-sale securities	[1]	16,868	14,524
Gross unrealized losses, available-for-sale securities	[1]	162	593
Fair value, available-for-sale securities	[1]	512,209	544,471
Amortized cost, held-to-maturity securities	[2]	424,463	484,205
Gross unrealized gains, held-to-maturity securities	[2]	2
Gross unrealized losses, held-to-maturity securities	[2]	9,767	14,423
Total	[2]	414,698	469,782
Debt securities | Residential mortgage-backed securities
Schedule of Investments [Line Items]
Amortized cost, available-for-sale securities		85,672	99,904
Gross unrealized gains, available-for-sale securities		1,694	1,420
Gross unrealized losses, available-for-sale securities		152	191
Fair value, available-for-sale securities		87,214	101,133
Debt securities | Commercial mortgage-backed securities
Schedule of Investments [Line Items]
Amortized cost, available-for-sale securities		543,378	495,313
Gross unrealized gains, available-for-sale securities		5,850	4,914
Gross unrealized losses, available-for-sale securities		117	104
Fair value, available-for-sale securities		549,111	500,123
Debt securities | Japanese corporate bonds and other debt securities
Schedule of Investments [Line Items]
Amortized cost, available-for-sale securities		1,792,730	1,743,309
Gross unrealized gains, available-for-sale securities		11,931	7,686
Gross unrealized losses, available-for-sale securities		1,731	1,561
Fair value, available-for-sale securities		1,802,930	1,749,434
Debt securities | Foreign corporate bonds and other debt securities
Schedule of Investments [Line Items]
Amortized cost, available-for-sale securities	[3]	740,431	778,088
Gross unrealized gains, available-for-sale securities	[3]	3,248	3,047
Gross unrealized losses, available-for-sale securities	[3]	164	226
Fair value, available-for-sale securities	[3]	¥ 743,515	¥ 780,909
[1]	Agency mortgage-backed securities presented in this line consist of Japanese and Foreign agency mortgage-backed securities, of which the fair values were ¥517,330 million and ¥27,141 million, respectively, at March 31, 2019, and ¥512,144 million and ¥65 million, respectively, at September 30, 2019. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise. Foreign agency mortgage-backed securities primarily consist of Government National Mortgage Association (“Ginnie Mae”) securities, which are guaranteed by the United States government.
[2]	All Agency mortgage-backed securities presented in this line are Ginnie Mae securities.
[3]	Other debt securities presented in this line primarily consist of Foreign negotiable certificates of deposit (“ NCDs”) and asset-backed securities (“ABS”), of which the total fair values were ¥246,503 million at March 31, 2019, and ¥226,899 million at September 30, 2019.

Investments (Amortized Cost, _2

Investments (Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value of Available-for-Sale and Held-to-Maturity Securities) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Schedule of Investments [Line Items]
Fair value, available-for-sale securities		¥ 17,690,583	¥ 18,133,916
Debt securities | Agency mortgage-backed securities
Schedule of Investments [Line Items]
Fair value, available-for-sale securities	[1]	512,209	544,471
Debt securities | Foreign agency mortgage-backed securities | Agency mortgage-backed securities
Schedule of Investments [Line Items]
Fair value, available-for-sale securities		512,144	27,141
Debt securities | Japanese agency mortgage-backed securities | Agency mortgage-backed securities
Schedule of Investments [Line Items]
Fair value, available-for-sale securities		65	517,330
Foreign government and corporate debt securities | Negotiable Certificates of Deposits and Asset- Backed Securities
Schedule of Investments [Line Items]
Fair value, available-for-sale securities		¥ 226,899	¥ 246,503
[1]	Agency mortgage-backed securities presented in this line consist of Japanese and Foreign agency mortgage-backed securities, of which the fair values were ¥517,330 million and ¥27,141 million, respectively, at March 31, 2019, and ¥512,144 million and ¥65 million, respectively, at September 30, 2019. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise. Foreign agency mortgage-backed securities primarily consist of Government National Mortgage Association (“Ginnie Mae”) securities, which are guaranteed by the United States government.

Investments (Amortized Cost and

Investments (Amortized Cost and Fair Value of Available-for-Sale and Held-to-Maturity Securities by Contractual Maturity) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost		¥ 8,426,011
Due after one year through five years, amortized cost		6,285,127
Due after five years through ten years,amortized cost		2,017,359
Due after ten years, amortized cost		915,436
Total		17,643,933
Due in one year or less, amortized cost		159,987
Due after one year through five years, amortized cost		439,916
Due after five years through ten years, amortized cost		40,010
Due after ten years, amortized cost		424,463
Amortized cost, held-to-maturity securities		1,064,376	¥ 1,604,104
Due in one year or less, fair value		8,432,027
Due after one year through five years, fair value		6,297,471
Due after five years through ten years, fair value		2,021,373
Due after ten years, fair value		939,712
Total		17,690,583
Due in one year or less, fair value		160,192
Due after one year through five years, fair value		458,337
Due after five years through ten years, fair value		41,582
Due after ten years, fair value		414,698
Total		1,074,809	1,609,588
Debt securities | Japanese government bonds
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost		5,907,368
Due after one year through five years, amortized cost		4,501,734
Due after five years through ten years,amortized cost		1,010,880
Total		11,419,982
Due in one year or less, amortized cost		159,987
Due after one year through five years, amortized cost		439,916
Due after five years through ten years, amortized cost		40,010
Amortized cost, held-to-maturity securities		639,913	1,119,899
Due in one year or less, fair value		5,911,536
Due after one year through five years, fair value		4,507,477
Due after five years through ten years, fair value		1,007,852
Total		11,426,865
Due in one year or less, fair value		160,192
Due after one year through five years, fair value		458,337
Due after five years through ten years, fair value		41,582
Total		660,111	1,139,806
Debt securities | Japanese local government bonds
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost		9,207
Due after one year through five years, amortized cost		148,811
Due after five years through ten years,amortized cost		73,113
Due after ten years, amortized cost		3,214
Total		234,345
Due in one year or less, fair value		9,253
Due after one year through five years, fair value		149,149
Due after five years through ten years, fair value		73,418
Due after ten years, fair value		3,342
Total		235,162
Debt securities | U.S. Treasury bonds and federal agency securities
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost		957,039
Due after one year through five years, amortized cost		43,645
Total		1,000,684
Due in one year or less, fair value		957,493
Due after one year through five years, fair value		43,592
Total		1,001,085
Debt securities | Other foreign government bonds
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost		1,077,745
Due after one year through five years, amortized cost		253,463
Total		1,331,208
Due in one year or less, fair value		1,078,329
Due after one year through five years, fair value		254,163
Total		1,332,492
Debt securities | Agency mortgage-backed securities
Investments Classified by Contractual Maturity Date [Line Items]
Due after ten years, amortized cost		495,503
Total		495,503
Due after ten years, amortized cost		424,463
Amortized cost, held-to-maturity securities	[1]	424,463	484,205
Due after ten years, fair value		512,209
Total		512,209
Due after ten years, fair value		414,698
Total	[1]	414,698	¥ 469,782
Debt securities | Residential mortgage-backed securities
Investments Classified by Contractual Maturity Date [Line Items]
Due after ten years, amortized cost		85,672
Total		85,672
Due after ten years, fair value		87,214
Total		87,214
Debt securities | Commercial mortgage-backed securities
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost		3,379
Due after one year through five years, amortized cost		187,887
Due after five years through ten years,amortized cost		331,837
Due after ten years, amortized cost		20,275
Total		543,378
Due in one year or less, fair value		3,385
Due after one year through five years, fair value		189,294
Due after five years through ten years, fair value		336,106
Due after ten years, fair value		20,326
Total		549,111
Debt securities | Japanese corporate bonds and other debt securities
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost		94,985
Due after one year through five years, amortized cost		863,381
Due after five years through ten years,amortized cost		526,430
Due after ten years, amortized cost		307,934
Total		1,792,730
Due in one year or less, fair value		95,179
Due after one year through five years, fair value		865,299
Due after five years through ten years, fair value		528,669
Due after ten years, fair value		313,783
Total		1,802,930
Debt securities | Foreign corporate bonds and other debt securities
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost		376,288
Due after one year through five years, amortized cost		286,206
Due after five years through ten years,amortized cost		75,099
Due after ten years, amortized cost		2,838
Total		740,431
Due in one year or less, fair value		376,852
Due after one year through five years, fair value		288,497
Due after five years through ten years, fair value		75,328
Due after ten years, fair value		2,838
Total		¥ 743,515
[1]	All Agency mortgage-backed securities presented in this line are Ginnie Mae securities.

Investments - Additional Inform

Investments - Additional Information (Detail) - JPY (¥) ¥ in Millions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2019
Gain (Loss) on Securities [Line Items]
Equity method Investments, carrying value	¥ 372,006		¥ 354,268
Held-to-maturity Securities
Gain (Loss) on Securities [Line Items]
Impairment loss on securities	¥ 0	¥ 0
Orient Corporation
Gain (Loss) on Securities [Line Items]
Percentage of proportionate share to the total outstanding common stock	49.00%
Equity securities (marketable)
Gain (Loss) on Securities [Line Items]
Equity method Investments, carrying value	¥ 207,210		201,034
Equity method Investments, aggregated market values	¥ 373,477		¥ 308,137

Investments (Gross Unrealized L

Investments (Gross Unrealized Losses and Fair Value of Available-for-Sale and Held-to-Maturity Securities, Aggregated by Length of Time that Individual Securities Have Been in a Continuous Unrealized Loss Position) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		¥ 4,060,553	¥ 3,809,946
Less than 12 months Gross unrealized losses, available-for-sale securities		5,255	3,137
12 months or more Fair value, available-for-sale securities		837,610	2,010,191
12 months or more Gross unrealized losses, available-for-sale securities		2,209	3,309
Total Fair value, available-for-sale securities		4,898,163	5,820,137
Total Gross unrealized losses, available-for-sale securities		7,464	6,446
12 months or more Fair value, held-to-maturity securities		412,250	469,782
12 months or more Gross unrealized losses, held-to-maturity securities		9,767	14,423
Total Fair value, held-to-maturity securities		412,250	469,782
Total Gross unrealized losses, held-to-maturity securities		9,767	14,423
Debt securities | Japanese government bonds
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		2,634,254	2,296,536
Less than 12 months Gross unrealized losses, available-for-sale securities		3,208	1,441
12 months or more Fair value, available-for-sale securities		291,304	1,332,688
12 months or more Gross unrealized losses, available-for-sale securities		1,039	1,557
Total Fair value, available-for-sale securities		2,925,558	3,629,224
Total Gross unrealized losses, available-for-sale securities		4,247	2,998
Debt securities | Japanese local government bonds
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		40,638	9,752
Less than 12 months Gross unrealized losses, available-for-sale securities		101	32
12 months or more Fair value, available-for-sale securities		32,510	38,873
12 months or more Gross unrealized losses, available-for-sale securities		68	55
Total Fair value, available-for-sale securities		73,148	48,625
Total Gross unrealized losses, available-for-sale securities		169	87
Debt securities | U.S. Treasury bonds and federal agency securities
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		381,789	506,176
Less than 12 months Gross unrealized losses, available-for-sale securities		430	231
Total Fair value, available-for-sale securities		381,789	506,176
Total Gross unrealized losses, available-for-sale securities		430	231
Debt securities | Other foreign government bonds
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		480,958	438,771
Less than 12 months Gross unrealized losses, available-for-sale securities		292	321
12 months or more Fair value, available-for-sale securities			26,782
12 months or more Gross unrealized losses, available-for-sale securities			134
Total Fair value, available-for-sale securities		480,958	465,553
Total Gross unrealized losses, available-for-sale securities		292	455
Debt securities | Agency mortgage-backed securities
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities	[1]	1,248	466
Less than 12 months Gross unrealized losses, available-for-sale securities	[1]	2	2
12 months or more Fair value, available-for-sale securities	[1]	10,280	37,706
12 months or more Gross unrealized losses, available-for-sale securities	[1]	160	591
Total Fair value, available-for-sale securities	[1]	11,528	38,172
Total Gross unrealized losses, available-for-sale securities	[2]	162	593
12 months or more Fair value, held-to-maturity securities	[3]	412,250	469,782
12 months or more Gross unrealized losses, held-to-maturity securities	[3]	9,767	14,423
Total Fair value, held-to-maturity securities	[3]	412,250	469,782
Total Gross unrealized losses, held-to-maturity securities	[3]	9,767	14,423
Debt securities | Residential mortgage-backed securities
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		3,221
Less than 12 months Gross unrealized losses, available-for-sale securities		33
12 months or more Fair value, available-for-sale securities		11,000	16,729
12 months or more Gross unrealized losses, available-for-sale securities		119	191
Total Fair value, available-for-sale securities		14,221	16,729
Total Gross unrealized losses, available-for-sale securities		152	191
Debt securities | Commercial mortgage-backed securities
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		12,315	11,256
Less than 12 months Gross unrealized losses, available-for-sale securities		86	44
12 months or more Fair value, available-for-sale securities		17,649	36,760
12 months or more Gross unrealized losses, available-for-sale securities		31	60
Total Fair value, available-for-sale securities		29,964	48,016
Total Gross unrealized losses, available-for-sale securities		117	104
Debt securities | Japanese corporate bonds and other debt securities
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		332,240	417,825
Less than 12 months Gross unrealized losses, available-for-sale securities		945	924
12 months or more Fair value, available-for-sale securities		469,373	440,937
12 months or more Gross unrealized losses, available-for-sale securities		786	637
Total Fair value, available-for-sale securities		801,613	858,762
Total Gross unrealized losses, available-for-sale securities		1,731	1,561
Debt securities | Foreign corporate bonds and other debt securities
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		173,890	129,164
Less than 12 months Gross unrealized losses, available-for-sale securities		158	142
12 months or more Fair value, available-for-sale securities		5,494	79,716
12 months or more Gross unrealized losses, available-for-sale securities		6	84
Total Fair value, available-for-sale securities		179,384	208,880
Total Gross unrealized losses, available-for-sale securities	[4]	¥ 164	¥ 226
[1]	Agency mortgage-backed securities presented in this line consist of Japanese and Foreign agency mortgage-backed securities, of which the fair values were ¥11,107 million and ¥27,065 million, respectively, at March 31, 2019, and ¥11,528 million and ¥0 million, respectively, at September 30, 2019. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise. Foreign agency mortgage-backed securities primarily consist of Ginnie Mae securities, which are guaranteed by the United States government.
[2]	Agency mortgage-backed securities presented in this line consist of Japanese and Foreign agency mortgage-backed securities, of which the fair values were ¥517,330 million and ¥27,141 million, respectively, at March 31, 2019, and ¥512,144 million and ¥65 million, respectively, at September 30, 2019. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise. Foreign agency mortgage-backed securities primarily consist of Government National Mortgage Association (“Ginnie Mae”) securities, which are guaranteed by the United States government.
[3]	All Agency mortgage-backed securities presented in this line are Ginnie Mae securities.
[4]	Other debt securities presented in this line primarily consist of Foreign negotiable certificates of deposit (“ NCDs”) and asset-backed securities (“ABS”), of which the total fair values were ¥246,503 million at March 31, 2019, and ¥226,899 million at September 30, 2019.

Investments (Gross Unrealized_2

Investments (Gross Unrealized Losses and Fair Value of Available-for-Sale and Held-to-Maturity Securities, Aggregated by Length of Time that Individual Securities Have Been in a Continuous Unrealized Loss Position) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Gain (Loss) on Securities [Line Items]
Fair value, available-for-sale securities		¥ 4,898,163	¥ 5,820,137
Debt securities | Agency mortgage-backed securities
Gain (Loss) on Securities [Line Items]
Fair value, available-for-sale securities	[1]	11,528	38,172
Debt securities | Japanese agency mortgage-backed securities | Agency mortgage-backed securities
Gain (Loss) on Securities [Line Items]
Fair value, available-for-sale securities		11,528	11,107
Debt securities | Foreign agency mortgage-backed securities | Agency mortgage-backed securities
Gain (Loss) on Securities [Line Items]
Fair value, available-for-sale securities		¥ 0	¥ 27,065
[1]	Agency mortgage-backed securities presented in this line consist of Japanese and Foreign agency mortgage-backed securities, of which the fair values were ¥11,107 million and ¥27,065 million, respectively, at March 31, 2019, and ¥11,528 million and ¥0 million, respectively, at September 30, 2019. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise. Foreign agency mortgage-backed securities primarily consist of Ginnie Mae securities, which are guaranteed by the United States government.

Investments (Realized Gains and

Investments (Realized Gains and Losses on Sales of Available-for-Sale Securities) (Detail) - JPY (¥) ¥ in Millions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Debt Securities, Available-for-sale [Line Items]
Gross realized gains	¥ 9,955	¥ 36,183
Gross realized losses	(8,497)	(6,167)
Net realized gains (losses) on sales of available-for-sale securities	¥ 1,458	¥ 30,016

Investments - Summary of Detail

Investments - Summary of Details of Net Gains and Losses on Equity Securities (Detail) - JPY (¥) ¥ in Millions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Gain (Loss) on Securities [Line Items]
Net gains (losses) recognized during the period on equity securities	[1]	¥ (126,648)	¥ 306,788
Less: Net gains (losses) recognized during the period on equity securities sold during the period		(3,084)	116,308
Unrealized gains (losses) recognized during the reporting period on equity securities still held at the reporting period		¥ (123,564)	¥ 190,480
[1]	These amounts are revenues from contracts that do not meet the scope of ASC 606.

Investments - Summary of Equity

Investments - Summary of Equity Securities Without Readily Determinable Fair Values (Detail) - JPY (¥) ¥ in Millions	Sep. 30, 2019	Mar. 31, 2019
Equity Securities without Readily Determinable Fair Value [Line Items]
Carrying amounts at the end of the period	¥ 227,142	¥ 212,270
Downward adjustments and impairments	1,843	1,413
Upward adjustments	¥ 8,756	¥ 2,373

Investments - Summary of Downwa

Investments - Summary of Downward Adjustments and Impairments and Upward Adjustments (Detail) - JPY (¥) ¥ in Millions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Equity Securities without Readily Determinable Fair Value [Line Items]
Downward adjustments and impairments	¥ 430	¥ 976
Upward adjustments	¥ 6,527	¥ 1,837

Investments (Summary of Composi

Investments (Summary of Composition of Other Investments) (Detail) - JPY (¥) ¥ in Millions	Sep. 30, 2019	Mar. 31, 2019
Schedule of Investments [Line Items]
Equity method investments	¥ 372,006	¥ 354,268
Investments held by consolidated investment companies	36,229	35,472
Total	¥ 408,235	¥ 389,740

Loans (Loans Outstanding by Dom

Loans (Loans Outstanding by Domicile and Industry of Borrower) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[1]	¥ 84,003,729	¥ 82,952,090
Less: Unearned income and deferred loan fees-net		147,538	152,147
Loans outstanding		83,856,191	82,799,943
Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		55,236,639	54,409,144
Domestic | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		9,661,265	9,558,146
Domestic | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		9,193,059	8,954,823
Domestic | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		5,486,164	5,113,386
Domestic | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		5,292,337	5,163,267
Domestic | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		3,751,962	3,622,130
Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		4,460,760	4,303,231
Domestic | Government and public institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		2,186,690	2,358,904
Domestic | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[2]	5,581,548	5,477,452
Domestic | Mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		8,753,545	8,950,216
Domestic | Other individual loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		869,309	907,589
Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[3]	28,767,090	28,542,946
Foreign | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		9,489,618	9,126,392
Foreign | Government and public institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		338,037	296,872
Foreign | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		18,905,059	19,086,511
Foreign | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		¥ 34,376	¥ 33,171
[1]	Amounts represent loan balances before deducting unearned income and deferred loan fees.
[2]	Other industries of domestic includes trade receivables and lease receivables of consolidated VIEs.
[3]	The majority of total foreign consist of commercial and industrial loans.

Loans - Additional Information

Loans - Additional Information (Detail) - JPY (¥) ¥ in Millions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net losses on sales of loans	¥ 179	¥ 1,060
Loans held for sale	68,569		¥ 24,921
Impaired Financing Receivables with No Related Allowance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired loans partially charged off	¥ 20,430		¥ 25,097

Loans (Credit Quality Informati

Loans (Credit Quality Information of Loans Based on MHFG Group's Internal Rating System) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[1]	¥ 84,003,729	¥ 82,952,090
Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		55,236,639	54,409,144
Domestic | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		9,661,265	9,558,146
Domestic | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		9,193,059	8,954,823
Domestic | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		5,486,164	5,113,386
Domestic | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		5,292,337	5,163,267
Domestic | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		3,751,962	3,622,130
Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		4,460,760	4,303,231
Domestic | Government and public institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		2,186,690	2,358,904
Domestic | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[2]	5,581,548	5,477,452
Domestic | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		9,622,854	9,857,805
Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[3]	28,767,090	28,542,946
Foreign | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		9,489,618	9,126,392
Foreign | Government and public institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		338,037	296,872
Foreign | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		18,905,059	19,086,511
Foreign | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		34,376	33,171
Financing Receivables Not Impaired | Normal obligors | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		66,542,190	65,286,588
Financing Receivables Not Impaired | Normal obligors | Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	10,129,382	10,372,030
Financing Receivables Not Impaired | Normal obligors | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5]	5,519,710	5,456,385
Financing Receivables Not Impaired | Normal obligors | Domestic | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		41,259,151	40,303,480
Financing Receivables Not Impaired | Normal obligors | Domestic | Corporate | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		9,299,310	9,209,834
Financing Receivables Not Impaired | Normal obligors | Domestic | Corporate | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		8,452,801	8,186,308
Financing Receivables Not Impaired | Normal obligors | Domestic | Corporate | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		5,113,878	4,761,724
Financing Receivables Not Impaired | Normal obligors | Domestic | Corporate | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		4,839,416	4,686,541
Financing Receivables Not Impaired | Normal obligors | Domestic | Corporate | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		3,608,666	3,472,991
Financing Receivables Not Impaired | Normal obligors | Domestic | Corporate | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		4,411,489	4,262,125
Financing Receivables Not Impaired | Normal obligors | Domestic | Corporate | Government and public institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		2,186,682	2,358,899
Financing Receivables Not Impaired | Normal obligors | Domestic | Corporate | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[2]	3,155,810	3,131,072
Financing Receivables Not Impaired | Normal obligors | Domestic | Corporate | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		191,099	233,986
Financing Receivables Not Impaired | Normal obligors | Domestic | Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	10,119,507	10,362,135
Financing Receivables Not Impaired | Normal obligors | Domestic | Retail | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	66,098	69,080
Financing Receivables Not Impaired | Normal obligors | Domestic | Retail | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	486,803	505,142
Financing Receivables Not Impaired | Normal obligors | Domestic | Retail | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	160,329	165,643
Financing Receivables Not Impaired | Normal obligors | Domestic | Retail | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	152,789	161,392
Financing Receivables Not Impaired | Normal obligors | Domestic | Retail | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	67,073	71,934
Financing Receivables Not Impaired | Normal obligors | Domestic | Retail | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	1,697	1,534
Financing Receivables Not Impaired | Normal obligors | Domestic | Retail | Government and public institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	8	5
Financing Receivables Not Impaired | Normal obligors | Domestic | Retail | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	2,384	2,450
Financing Receivables Not Impaired | Normal obligors | Domestic | Retail | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	9,182,326	9,384,955
Financing Receivables Not Impaired | Normal obligors | Domestic | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		2,494,714	2,455,064	[5]
Financing Receivables Not Impaired | Normal obligors | Domestic | Other | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5]	14,732	19,805
Financing Receivables Not Impaired | Normal obligors | Domestic | Other | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5]	11,751	15,920
Financing Receivables Not Impaired | Normal obligors | Domestic | Other | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5]	1,883	3,281
Financing Receivables Not Impaired | Normal obligors | Domestic | Other | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5]	17,127	26,881
Financing Receivables Not Impaired | Normal obligors | Domestic | Other | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5]	283	934
Financing Receivables Not Impaired | Normal obligors | Domestic | Other | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5]	276	72
Financing Receivables Not Impaired | Normal obligors | Domestic | Other | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[2],[5]	2,384,867	2,323,197
Financing Receivables Not Impaired | Normal obligors | Domestic | Other | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5]	63,795	64,974
Financing Receivables Not Impaired | Normal obligors | Foreign | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		25,283,039	24,983,108
Financing Receivables Not Impaired | Normal obligors | Foreign | Corporate | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		8,838,656	8,623,103
Financing Receivables Not Impaired | Normal obligors | Foreign | Corporate | Government and public institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		338,037	296,870
Financing Receivables Not Impaired | Normal obligors | Foreign | Corporate | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		16,104,914	16,061,655
Financing Receivables Not Impaired | Normal obligors | Foreign | Corporate | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		1,432	1,480
Financing Receivables Not Impaired | Normal obligors | Foreign | Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	9,875	9,895
Financing Receivables Not Impaired | Normal obligors | Foreign | Retail | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	292	182
Financing Receivables Not Impaired | Normal obligors | Foreign | Retail | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	9,583	9,713
Financing Receivables Not Impaired | Normal obligors | Foreign | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5]	3,024,996	3,001,321
Financing Receivables Not Impaired | Normal obligors | Foreign | Other | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5]	638,508	492,831
Financing Receivables Not Impaired | Normal obligors | Foreign | Other | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5]	2,367,172	2,488,800
Financing Receivables Not Impaired | Normal obligors | Foreign | Other | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5]	19,316	19,690
Financing Receivables Not Impaired | Watch obligors | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[6]	1,000,172	999,405
Financing Receivables Not Impaired | Watch obligors | Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	136,798	145,546
Financing Receivables Not Impaired | Watch obligors | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5],[6]	47,353	46,004
Financing Receivables Not Impaired | Watch obligors | Domestic | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		668,660	641,554	[6]
Financing Receivables Not Impaired | Watch obligors | Domestic | Corporate | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[6]	123,362	141,202
Financing Receivables Not Impaired | Watch obligors | Domestic | Corporate | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[6]	179,437	186,753
Financing Receivables Not Impaired | Watch obligors | Domestic | Corporate | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[6]	111,672	90,578
Financing Receivables Not Impaired | Watch obligors | Domestic | Corporate | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[6]	123,201	127,695
Financing Receivables Not Impaired | Watch obligors | Domestic | Corporate | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[6]	45,291	37,593
Financing Receivables Not Impaired | Watch obligors | Domestic | Corporate | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[6]	37,516	28,881
Financing Receivables Not Impaired | Watch obligors | Domestic | Corporate | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[2],[6]	12,120	7,725
Financing Receivables Not Impaired | Watch obligors | Domestic | Corporate | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[6]	36,061	21,127
Financing Receivables Not Impaired | Watch obligors | Domestic | Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	136,798	145,546
Financing Receivables Not Impaired | Watch obligors | Domestic | Retail | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	7,921	8,278
Financing Receivables Not Impaired | Watch obligors | Domestic | Retail | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	12,710	14,490
Financing Receivables Not Impaired | Watch obligors | Domestic | Retail | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	17,210	18,586
Financing Receivables Not Impaired | Watch obligors | Domestic | Retail | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	24,216	25,553
Financing Receivables Not Impaired | Watch obligors | Domestic | Retail | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	7,920	7,472
Financing Receivables Not Impaired | Watch obligors | Domestic | Retail | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	334	319
Financing Receivables Not Impaired | Watch obligors | Domestic | Retail | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	407	421
Financing Receivables Not Impaired | Watch obligors | Domestic | Retail | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[4]	66,080	70,427
Financing Receivables Not Impaired | Watch obligors | Domestic | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		12,609	6,721
Financing Receivables Not Impaired | Watch obligors | Domestic | Other | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5],[6]	542	1,303
Financing Receivables Not Impaired | Watch obligors | Domestic | Other | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5],[6]		25
Financing Receivables Not Impaired | Watch obligors | Domestic | Other | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5],[6]		1
Financing Receivables Not Impaired | Watch obligors | Domestic | Other | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5],[6]	605	591
Financing Receivables Not Impaired | Watch obligors | Domestic | Other | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[2],[5],[6]	10,364	3,633
Financing Receivables Not Impaired | Watch obligors | Domestic | Other | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5],[6]	1,098	1,168
Financing Receivables Not Impaired | Watch obligors | Foreign | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[6]	331,512	357,851
Financing Receivables Not Impaired | Watch obligors | Foreign | Corporate | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[6]	12,454	10,458
Financing Receivables Not Impaired | Watch obligors | Foreign | Corporate | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[6]	317,303	347,060
Financing Receivables Not Impaired | Watch obligors | Foreign | Corporate | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[6]	1,755	333
Financing Receivables Not Impaired | Watch obligors | Foreign | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5],[6]	34,744	39,283
Financing Receivables Not Impaired | Watch obligors | Foreign | Other | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5],[6]	33,750	38,404
Financing Receivables Not Impaired | Watch obligors | Foreign | Other | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[5],[6]	994	879
Financing Receivables Impaired | Impaired loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		628,124	646,132
Financing Receivables Impaired | Impaired loans | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		545,200	494,644
Financing Receivables Impaired | Impaired loans | Domestic | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		149,300	108,644
Financing Receivables Impaired | Impaired loans | Domestic | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		49,557	46,185
Financing Receivables Impaired | Impaired loans | Domestic | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		81,192	73,573
Financing Receivables Impaired | Impaired loans | Domestic | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		134,983	134,614
Financing Receivables Impaired | Impaired loans | Domestic | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		22,729	31,206
Financing Receivables Impaired | Impaired loans | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		9,448	10,300
Financing Receivables Impaired | Impaired loans | Domestic | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding	[2]	15,596	8,954
Financing Receivables Impaired | Impaired loans | Domestic | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		82,395	81,168
Financing Receivables Impaired | Impaired loans | Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		82,924	151,488
Financing Receivables Impaired | Impaired loans | Foreign | Government and public institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding			2
Financing Receivables Impaired | Impaired loans | Foreign | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		81,628	150,410
Financing Receivables Impaired | Impaired loans | Foreign | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding		¥ 1,296	¥ 1,076
[1]	Amounts represent loan balances before deducting unearned income and deferred loan fees.
[2]	Other industries of domestic includes trade receivables and lease receivables of consolidated VIEs.
[3]	The majority of total foreign consist of commercial and industrial loans.
[4]	The primary component of the retail portfolio segment is mortgage loans to individuals which obligor category is classified based on past due status. The trigger to reclassify obligors from normal obligors to watch obligors excluding special attention obligors is when the past due status is more than 30 days.
[5]	Non-impaired loans held by subsidiaries other than MHBK and MHTB constitute other, since their portfolio segments are not identical to those of MHBK and MHTB.
[6]	Special attention obligors are watch obligors with debt in TDR or 90 days or more delinquent debt. Loans to such obligors are considered impaired.

Loans (Impaired Loans Informati

Loans (Impaired Loans Information) (Detail) - JPY (¥) ¥ in Millions		6 Months Ended		12 Months Ended
		Sep. 30, 2019		Mar. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment requiring an allowance for loan losses	[1]	¥ 475,033		¥ 529,048
Recorded investment not requiring an allowance for loan losses	[1]	153,091	[2]	117,084
Total	[1]	628,124		646,132
Unpaid principal balance		679,556		694,995
Related allowance	[3]	152,391		169,245
Average recorded investment		637,128		609,745
Interest income recognized	[4]	4,726		8,157
Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment requiring an allowance for loan losses	[1]	419,394		409,969
Recorded investment not requiring an allowance for loan losses	[1]	125,806	[2]	84,675
Total	[1]	545,200		494,644
Unpaid principal balance		583,017		530,011
Related allowance	[3]	121,191		121,900
Average recorded investment		519,922		496,186
Interest income recognized	[4]	3,328		6,639
Domestic | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment requiring an allowance for loan losses	[1]	100,021		103,039
Recorded investment not requiring an allowance for loan losses	[1]	49,279	[2]	5,605
Total	[1]	149,300		108,644
Unpaid principal balance		152,358		111,533
Related allowance	[3]	35,530		39,301
Average recorded investment		128,972		122,764
Interest income recognized	[4]	796		1,404
Domestic | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment requiring an allowance for loan losses	[1]	39,756		36,873
Recorded investment not requiring an allowance for loan losses	[1]	9,801	[2]	9,312
Total	[1]	49,557		46,185
Unpaid principal balance		56,503		51,158
Related allowance	[3]	8,491		4,661
Average recorded investment		47,871		42,224
Interest income recognized	[4]	279		487
Domestic | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment requiring an allowance for loan losses	[1]	72,044		64,021
Recorded investment not requiring an allowance for loan losses	[1]	9,148	[2]	9,552
Total	[1]	81,192		73,573
Unpaid principal balance		86,259		79,736
Related allowance	[3]	16,689		16,311
Average recorded investment		77,383		67,679
Interest income recognized	[4]	460		1,058
Domestic | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment requiring an allowance for loan losses	[1]	125,938		124,911
Recorded investment not requiring an allowance for loan losses	[1]	9,045	[2]	9,703
Total	[1]	134,983		134,614
Unpaid principal balance		151,913		147,665
Related allowance	[3]	43,339		38,763
Average recorded investment		134,798		130,860
Interest income recognized	[4]	850		1,814
Domestic | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment requiring an allowance for loan losses	[1]	20,272		28,297
Recorded investment not requiring an allowance for loan losses	[1]	2,457	[2]	2,909
Total	[1]	22,729		31,206
Unpaid principal balance		23,628		32,139
Related allowance	[3]	6,534		13,146
Average recorded investment		26,968		29,864
Interest income recognized	[4]	212		412
Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment requiring an allowance for loan losses	[1]	5,688		6,473
Recorded investment not requiring an allowance for loan losses	[1]	3,760	[2]	3,827
Total	[1]	9,448		10,300
Unpaid principal balance		9,447		10,300
Related allowance	[3]	1,001		1,327
Average recorded investment		9,874		10,671
Interest income recognized	[4]	51		109
Domestic | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment requiring an allowance for loan losses	[1]	15,323		8,867
Recorded investment not requiring an allowance for loan losses	[1]	273	[2]	87
Total	[1]	15,596		8,954
Unpaid principal balance		15,720		9,149
Related allowance	[3]	6,290		5,761
Average recorded investment		12,275		6,042
Interest income recognized	[4]	96		29
Domestic | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment requiring an allowance for loan losses	[1]	40,352		37,488
Recorded investment not requiring an allowance for loan losses	[1]	42,043	[2]	43,680
Total	[1]	82,395		81,168
Unpaid principal balance		87,189		88,331
Related allowance	[3]	3,317		2,630
Average recorded investment		81,781		86,082
Interest income recognized	[4]	584		1,326
Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment requiring an allowance for loan losses	[1],[5]	55,639		119,079
Recorded investment not requiring an allowance for loan losses	[1],[2],[5]	27,285		32,409
Total	[5]	82,924		151,488
Unpaid principal balance	[5]	96,539		164,984
Related allowance	[3],[5]	31,200		47,345
Average recorded investment	[5]	117,206		113,559
Interest income recognized	[4],[5]	¥ 1,398		¥ 1,518
[1]	Amounts represent the outstanding balances of nonaccrual loans. The MHFG Group’s policy for placing loans in nonaccrual status corresponds to the Group’s definition of impaired loans.
[2]	These impaired loans do not require an allowance for loan losses because the MHFG Group has sufficient collateral to cover probable loan losses.
[3]	The allowance for loan losses on impaired loans includes the allowance for groups of loans which were collectively evaluated for impairment, in addition to the allowance for those loans that were individually evaluated for impairment. The total carrying amount of the groups of loans which were collectively evaluated for impairment at March 31, 2019 and September 30, 2019 was ¥257,099 million and ¥250,121 million, respectively.
[4]	Amounts represent the amount of interest income on impaired loans recognized on a cash basis and included in Interest income on loans in the consolidated statements of income.
[5]	The majority of total foreign consist of commercial and industrial loans.

Loans (Impaired Loans Informa_2

Loans (Impaired Loans Information) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment	[1]	¥ 628,124	¥ 646,132
Small balance homogeneous loans of which were collectively evaluated for impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment		¥ 250,121	¥ 257,099
[1]	Amounts represent the outstanding balances of nonaccrual loans. The MHFG Group’s policy for placing loans in nonaccrual status corresponds to the Group’s definition of impaired loans.

Loans (Troubled Debt Restructur

Loans (Troubled Debt Restructurings Entered Modified Periods by Type of Concession Granted) (Detail) - JPY (¥) ¥ in Millions		6 Months Ended
		Sep. 30, 2019		Sep. 30, 2018
Financing Receivable, Modifications [Line Items]
Loan forgiveness or debt to equity swaps Recorded investment	[1]	¥ 1,159		¥ 1,008
Loan forgiveness or debt to equity swaps charge-off		8,728		2,012
Interest rate reduction and/or postponement of principal and/or interest		257,573		203,239
Domestic
Financing Receivable, Modifications [Line Items]
Loan forgiveness or debt to equity swaps Recorded investment	[1]	689
Loan forgiveness or debt to equity swaps charge-off		3,806
Interest rate reduction and/or postponement of principal and/or interest		218,927		193,746
Domestic | Manufacturing
Financing Receivable, Modifications [Line Items]
Loan forgiveness or debt to equity swaps Recorded investment	[1]	689
Loan forgiveness or debt to equity swaps charge-off		3,806
Interest rate reduction and/or postponement of principal and/or interest		57,879		51,161
Domestic | Construction and real estate
Financing Receivable, Modifications [Line Items]
Interest rate reduction and/or postponement of principal and/or interest		15,478		7,764
Domestic | Services
Financing Receivable, Modifications [Line Items]
Interest rate reduction and/or postponement of principal and/or interest		44,185		29,203
Domestic | Wholesale and retail
Financing Receivable, Modifications [Line Items]
Interest rate reduction and/or postponement of principal and/or interest		77,117		75,593
Domestic | Transportation and communications
Financing Receivable, Modifications [Line Items]
Interest rate reduction and/or postponement of principal and/or interest		7,916		13,999
Domestic | Banks and other financial institutions
Financing Receivable, Modifications [Line Items]
Interest rate reduction and/or postponement of principal and/or interest		7,639		7,160
Domestic | Other industries
Financing Receivable, Modifications [Line Items]
Interest rate reduction and/or postponement of principal and/or interest		639
Domestic | Individuals
Financing Receivable, Modifications [Line Items]
Interest rate reduction and/or postponement of principal and/or interest		8,074		8,866
Foreign
Financing Receivable, Modifications [Line Items]
Loan forgiveness or debt to equity swaps Recorded investment	[1],[2]	470		1,008
Loan forgiveness or debt to equity swaps charge-off		4,922	[2]	2,012
Interest rate reduction and/or postponement of principal and/or interest		¥ 38,646	[2]	¥ 9,493
[1]	Amounts represent the book values of loans immediately after the restructurings.
[2]	The majority of total foreign consist of commercial and industrial loans.

Loans (Payment Defaults Occurre

Loans (Payment Defaults Occurred During Periods with Respect to Loans Modified as Troubled Debt Restructurings within Previous Six Months) (Detail) - JPY (¥) ¥ in Millions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Financing Receivable, Modifications [Line Items]
Recorded investment	¥ 16,790	¥ 10,837
Domestic
Financing Receivable, Modifications [Line Items]
Recorded investment	10,354	10,837
Domestic | Manufacturing
Financing Receivable, Modifications [Line Items]
Recorded investment	2,391	383
Domestic | Construction and real estate
Financing Receivable, Modifications [Line Items]
Recorded investment	171	390
Domestic | Services
Financing Receivable, Modifications [Line Items]
Recorded investment	318	714
Domestic | Wholesale and retail
Financing Receivable, Modifications [Line Items]
Recorded investment	6,504	6,700
Domestic | Transportation and communications
Financing Receivable, Modifications [Line Items]
Recorded investment	86	409
Domestic | Individuals
Financing Receivable, Modifications [Line Items]
Recorded investment	884	¥ 2,241
Foreign
Financing Receivable, Modifications [Line Items]
Recorded investment	¥ 6,436

Loans (Age Analysis of Past Due

Loans (Age Analysis of Past Due Loans) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		¥ 175,186	¥ 155,737
Current		83,828,543	82,796,353
Total	[1]	84,003,729	82,952,090
Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		147,820	128,542
Current		55,088,819	54,280,602
Total		55,236,639	54,409,144
Domestic | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		9,317	9,759
Current		9,651,948	9,548,387
Total		9,661,265	9,558,146
Domestic | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		30,361	33,156
Current		9,162,698	8,921,667
Total		9,193,059	8,954,823
Domestic | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		8,547	4,323
Current		5,477,617	5,109,063
Total		5,486,164	5,113,386
Domestic | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		15,003	10,897
Current		5,277,334	5,152,370
Total		5,292,337	5,163,267
Domestic | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		2,626	2,738
Current		3,749,336	3,619,392
Total		3,751,962	3,622,130
Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		157	493
Current		4,460,603	4,302,738
Total		4,460,760	4,303,231
Domestic | Government and public institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current		2,186,690	2,358,904
Total		2,186,690	2,358,904
Domestic | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		221	59
Current		5,581,327	5,477,393
Total	[2]	5,581,548	5,477,452
Domestic | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		81,588	67,117
Current		9,541,266	9,790,688
Total		9,622,854	9,857,805
Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due	[3]	27,366	27,195
Current	[3]	28,739,724	28,515,751
Total	[3]	28,767,090	28,542,946
Foreign | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		9,489,618	9,126,392
Foreign | Government and public institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		338,037	296,872
30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		28,595	33,642
30-59 Days Past Due | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		27,414	32,974
30-59 Days Past Due | Domestic | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		733	2,210
30-59 Days Past Due | Domestic | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		834	1,010
30-59 Days Past Due | Domestic | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		390	633
30-59 Days Past Due | Domestic | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		2,317	1,614
30-59 Days Past Due | Domestic | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		106	363
30-59 Days Past Due | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		116	3
30-59 Days Past Due | Domestic | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due			2
30-59 Days Past Due | Domestic | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		22,918	27,139
30-59 Days Past Due | Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due	[3]	1,181	668
60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		32,962	15,142
60-89 Days Past Due | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		32,713	14,931
60-89 Days Past Due | Domestic | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		983	513
60-89 Days Past Due | Domestic | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		849	1,054
60-89 Days Past Due | Domestic | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		2,986	196
60-89 Days Past Due | Domestic | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		1,226	1,415
60-89 Days Past Due | Domestic | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		366	256
60-89 Days Past Due | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due			484
60-89 Days Past Due | Domestic | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		26,303	11,013
60-89 Days Past Due | Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due	[3]	249	211
90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		113,629	106,953
90 Days or More Past Due | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		87,693	80,637
90 Days or More Past Due | Domestic | Manufacturing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		7,601	7,036
90 Days or More Past Due | Domestic | Construction and real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		28,678	31,092
90 Days or More Past Due | Domestic | Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		5,171	3,494
90 Days or More Past Due | Domestic | Wholesale and retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		11,460	7,868
90 Days or More Past Due | Domestic | Transportation and communications
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		2,154	2,119
90 Days or More Past Due | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		41	6
90 Days or More Past Due | Domestic | Other industries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		221	57
90 Days or More Past Due | Domestic | Individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due		32,367	28,965
90 Days or More Past Due | Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due	[3]	¥ 25,936	¥ 26,316
[1]	Amounts represent loan balances before deducting unearned income and deferred loan fees.
[2]	Other industries of domestic includes trade receivables and lease receivables of consolidated VIEs.
[3]	The majority of total foreign consist of commercial and industrial loans.

Allowance for Loan Losses (Chan

Allowance for Loan Losses (Changes in Allowance for Loan Losses, Allowance for Loan Losses and Loans Outstanding Disaggregated on Basis of Impairment Method, by Portfolio Segment) (Detail) - JPY (¥) ¥ in Millions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of period		¥ 307,201	¥ 309,902
Provision (credit) for loan losses		13,773	(13,280)
Charge-offs		(29,034)	(31,264)
Recoveries		4,054	7,543
Net charge-offs		(24,980)	(23,721)
Others	[1]	(4,572)	1,588
Balance at end of period		291,422	274,489
Allowance for loan losses of which individually evaluated for impairment		131,915		¥ 150,527
Allowance for loan losses of which collectively evaluated for impairment		159,507		156,674
Loans	[2]	84,003,729		82,952,090
Loans of which individually evaluated for impairment		603,508		615,098
Loans of which collectively evaluated for impairment		83,400,221		82,336,992
Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of period		252,903	249,072
Provision (credit) for loan losses		17,275	(13,435)
Charge-offs		(24,288)	(27,419)
Recoveries		2,724	4,914
Net charge-offs		(21,564)	(22,505)
Others	[1]	(3,887)	2,519
Balance at end of period		244,727	215,651
Allowance for loan losses of which individually evaluated for impairment		124,693		139,472
Allowance for loan losses of which collectively evaluated for impairment		120,034		113,431
Loans	[2]	68,067,130		66,804,088
Loans of which individually evaluated for impairment		547,792		539,893
Loans of which collectively evaluated for impairment		67,519,338		66,264,195
Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of period		23,230	28,192
Provision (credit) for loan losses		(805)	(2,290)
Charge-offs		(1,397)	(1,243)
Recoveries		309	220
Net charge-offs		(1,088)	(1,023)
Balance at end of period		21,337	24,879
Allowance for loan losses of which individually evaluated for impairment		1,884		2,122
Allowance for loan losses of which collectively evaluated for impairment		19,453		21,108
Loans	[2]	10,343,150		10,596,994
Loans of which individually evaluated for impairment		20,099		20,886
Loans of which collectively evaluated for impairment		10,323,051		10,576,108
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of period		31,068	32,638
Provision (credit) for loan losses		(2,697)	2,445
Charge-offs		(3,349)	(2,602)
Recoveries		1,021	2,409
Net charge-offs		(2,328)	(193)
Others	[1]	(685)	(931)
Balance at end of period		25,358	¥ 33,959
Allowance for loan losses of which individually evaluated for impairment		5,338		8,933
Allowance for loan losses of which collectively evaluated for impairment		20,020		22,135
Loans	[2]	5,593,449		5,551,008
Loans of which individually evaluated for impairment		35,617		54,319
Loans of which collectively evaluated for impairment		¥ 5,557,832		¥ 5,496,689
[1]	Others includes primarily foreign exchange translation.
[2]	Amounts represent loan balances before deducting unearned income and deferred loan fees.

Other Assets and Liabilities (D

Other Assets and Liabilities (Details of Other Assets and Liabilities) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Other assets:
Receivables from brokers, dealers and customers for securities transactions	[1]	¥ 1,348,181	¥ 1,517,235
Other		358,547	400,676
Collateral pledged for derivative transactions		1,008,596	856,439
Margins provided for futures contracts		269,143	159,747
Other		865,875	857,814
Prepaid pension cost		860,365	850,472
ROU assets	[2]	647,185
Security deposits		108,293	123,317
Loans held for sale		68,569	24,921
Other		473,301	485,383
Total		6,008,055	5,276,004
Other liabilities:
Payables to brokers, dealers and customers for securities transactions	[1]	2,042,447	2,572,315
Other		451,208	442,776
Guaranteed trust principal	[3]	813,761	809,450
Lease Liabilities	[2]	656,409
Collateral accepted for derivative transactions		533,308	589,411
Margins accepted for futures contracts		541,070	339,863
Unearned income	[4]	120,908	126,594
Other		1,024,549	1,052,297
Total		¥ 6,183,660	¥ 5,932,706
[1]	Receivables from brokers, dealers and customers for securities transactions included ¥555,938 million and ¥181,535 million of such receivables of consolidated VIEs at March 31, 2019 and September 30, 2019, respectively. Payables to brokers, dealers and customers for securities transactions included ¥620,766 million and ¥172,473 million of such payables of consolidated VIEs at March 31, 2019 and September 30, 2019, respectively.
[2]	ROU assets and lease liabilities were recognized in connection with the adoption of ASU No.2016-02 on April 1, 2019. See Note 1 “Basis of presentation” and Note 2 “Recently issued accounting pronouncements” for further information.
[3]	Guaranteed trust principal is the liability of certain consolidated trust arrangements that meet the definition of a VIE for which the MHFG Group provides guarantees for the repayment of principal. See Note 15 “Variable interest entities and securitizations” for further discussion of the guaranteed principal money trusts.
[4]	Unearned income is primarily comprised of loan fees received from consumer loan customers when loans are made. This income is being deferred and recognized in earnings over the life of the loan.

Other Assets and Liabilities _2

Other Assets and Liabilities (Details of Other Assets and Liabilities) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Other Assets and Other Liabilities [Line Items]
Accounts receivable from brokers, dealers and customers for securities transactions	[1]	¥ 1,348,181	¥ 1,517,235
Accounts payable to brokers, dealers and customers for securities transactions	[1]	2,042,447	2,572,315
Consolidated VIEs
Other Assets and Other Liabilities [Line Items]
Accounts receivable from brokers, dealers and customers for securities transactions		181,535	555,938
Accounts payable to brokers, dealers and customers for securities transactions		¥ 172,473	¥ 620,766
[1]	Receivables from brokers, dealers and customers for securities transactions included ¥555,938 million and ¥181,535 million of such receivables of consolidated VIEs at March 31, 2019 and September 30, 2019, respectively. Payables to brokers, dealers and customers for securities transactions included ¥620,766 million and ¥172,473 million of such payables of consolidated VIEs at March 31, 2019 and September 30, 2019, respectively.

Preferred and Common Stock (Com

Preferred and Common Stock (Composition of Preferred Stock) (Detail) - shares	Sep. 30, 2019	Mar. 31, 2019
Class Fourteen Preferred Stock
Class of Stock [Line Items]
Number of shares Authorized	900,000,000	900,000,000
Number of shares Issued	0	0
Class Fifteen Preferred Stock
Class of Stock [Line Items]
Number of shares Authorized	900,000,000	900,000,000
Number of shares Issued	0	0
Class Sixteen Preferred Stock
Class of Stock [Line Items]
Number of shares Authorized	1,500,000,000	1,500,000,000
Number of shares Issued	0	0

Preferred and Common Stock - Su

Preferred and Common Stock - Summary of Changes in Number of Issued Shares of Common Stock (Detail)	12 Months Ended
	Mar. 31, 2019shares
Class of Stock [Line Items]
Balance at beginning of period	25,389,644,945
Issuance of new shares of common stock due to exercise of stock acquisition rights	2,854,000
Balance at end of period	25,392,498,945

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Changes in Each Component of AOCI) (Detail) - JPY (¥) ¥ in Millions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period		¥ 9,501,493
Less: reclassification adjustments for losses (gains) included in net income		(24,372)
Change during period		(56,583)	¥ (19,030)
Balance at end of fiscal year		9,486,573	9,831,837
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period		164,021	1,741,894
Cumulative effect of change in accounting principles	[1]	(1,052)	(1,535,142)
Balance at beginning of period, adjusted		162,969	206,752
Change during period		(56,254)	(18,837)
Balance at end of fiscal year		106,715	187,915
Net unrealized gains (losses) on available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period		22,019	1,556,585
Cumulative effect of change in accounting principles	[1]		(1,525,064)
Balance at beginning of period, adjusted		22,019	31,521
Unrealized gains (losses) during period		25,843	(25,155)
Less: reclassification adjustments for losses (gains) included in net income		(20,824)	(862)
Change during period		5,019	(26,017)
Balance at end of fiscal year		27,038	5,504
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period		(58,558)	(35,076)
Cumulative effect of change in accounting principles	[1]	(1,052)
Foreign currency translation adjustments during period		(63,466)	7,678
Balance at beginning of period, adjusted		(59,610)	(35,076)
Less: reclassification adjustments for losses (gains) included in net income
Change during period		(63,466)	7,678
Balance at end of fiscal year		(123,076)	(27,398)
Pension liability adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period		196,446	220,385
Unrealized gains (losses) during period		(1,720)	(218)
Less: reclassification adjustments for losses (gains) included in net income		(2,130)	(2,916)
Change during period		(3,850)	(3,134)
Balance at end of fiscal year		192,596	217,251
Accumulated Own Credit Risk Adjustment Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	[2]	4,114
Cumulative effect of change in accounting principles	[2]		(10,078)
Balance at beginning of period, adjusted	[2]	4,114	(10,078)
Unrealized gains (losses) during period	[2]	7,320	2,656
Less: reclassification adjustments for losses (gains) included in net income	[2]	(1,277)	(20)
Change during period	[2]	6,043	2,636
Balance at end of fiscal year	[2]	¥ 10,157	¥ (7,442)
[1]	See Note 2 “Recently issued accounting pronouncements” for further details of the cumulative-effect adjustment for AOCI.
[2]	The MHFG Group adopted ASU No.2016-01 on April 1, 2018. The ASU requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. See Note 2 “Recently issued accounting pronouncements” for further details.

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Amounts Reclassified Out of Accumulated Other Comprehensive Income into Net Income) (Detail) ¥ in Millions	6 Months Ended
	Sep. 30, 2019JPY (¥)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Before tax	¥ 35,089	[1]
Tax effect	(10,717)	[2]
Net of tax before allocation to noncontrolling interests	24,372
Net of tax attributable to noncontrolling interests	(141)	[2]
Net of tax attributable to MHFG shareholders	24,231
Accumulated Net Unrealized Investment Gain (Loss) | Gain (Loss) on Investments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Before tax	30,013	[1]
Tax effect	(9,192)	[2]
Net of tax before allocation to noncontrolling interests	20,821
Net of tax attributable to noncontrolling interests	3	[2]
Net of tax attributable to MHFG shareholders	20,824
Accumulated Defined Benefit Plans Adjustment | Salaries and employee benefits
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Before tax	3,155	[1]
Tax effect	(937)	[2]
Net of tax before allocation to noncontrolling interests	2,218
Net of tax attributable to noncontrolling interests	(88)	[2]
Net of tax attributable to MHFG shareholders	2,130
Accumulated Own Credit Risk Adjustment | Other Noninterest Income (Expenses)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Before tax	1,921	[1]
Tax effect	(588)	[2]
Net of tax before allocation to noncontrolling interests	1,333
Net of tax attributable to noncontrolling interests	(56)	[2]
Net of tax attributable to MHFG shareholders	¥ 1,277
[1]	The financial statement line item in which the amounts in the Before tax column are reported in the Consolidated statements of income is listed to the right of the table.
[2]	The financial statement line items in which the amounts in the Tax effect and the Net of tax attributable to noncontrolling interest columns are reported in the consolidated statements of income are Income tax expense and Net income, respectively.

Regulatory Matters (Capital Ade

Regulatory Matters (Capital Adequacy Ratios of MHFG, MHBK, and MHTB Calculated in Accordance with Japanese GAAP and Guidelines Established by Financial Services Agency) (Detail) - JPY (¥) ¥ in Billions		Sep. 30, 2019	Mar. 31, 2019
Mizuho Financial Group Inc | Consolidated
Common Equity Tier 1 capital:
Required	[1]	¥ 4,878	¥ 4,661
Actual		7,383	7,390
Tier 1 capital:
Required	[1]	5,787	5,529
Actual		¥ 9,162	¥ 9,232
Required	[1]	9.55%	9.55%
Actual		15.11%	15.94%
Total risk-based capital:
Required	[1]	¥ 6,999	¥ 6,687
Actual		¥ 10,865	¥ 10,918
Required	[1]	11.55%	11.55%
Actual		17.92%	18.85%
Common Equity Tier 1 capital:
Required	[1]	8.05%	8.05%
Actual		12.18%	12.76%
Leverage Ratio:
Required		3.00%	3.00%
Required		¥ 6,327	¥ 6,257
Actual		¥ 9,162	¥ 9,232
Actual		4.34%	4.42%
Mizuho Bank Limited | Consolidated
Common Equity Tier 1 capital:
Required		¥ 2,497	¥ 2,388
Actual		6,761	6,690
Tier 1 capital:
Required		3,329	3,184
Actual		¥ 8,533	¥ 8,527
Required		6.00%	6.00%
Actual		15.37%	16.06%
Total risk-based capital:
Required		¥ 4,439	¥ 4,246
Actual		¥ 10,142	¥ 10,098
Required		8.00%	8.00%
Actual		18.27%	19.02%
Common Equity Tier 1 capital:
Required		4.50%	4.50%
Actual		12.18%	12.60%
Leverage Ratio:
Required		¥ 5,815	¥ 5,758
Required		3.00%	3.00%
Actual		¥ 8,533	¥ 8,527
Actual		4.40%	4.44%
Mizuho Bank Limited | Non-consolidated
Common Equity Tier 1 capital:
Required		¥ 2,350	¥ 2,272
Actual		6,423	6,363
Tier 1 capital:
Required		3,133	3,029
Actual		¥ 8,191	¥ 8,199
Required		6.00%	6.00%
Actual		15.68%	16.23%
Total risk-based capital:
Required		¥ 4,177	¥ 4,039
Actual		¥ 9,792	¥ 9,757
Required		8.00%	8.00%
Actual		18.75%	19.32%
Common Equity Tier 1 capital:
Required		4.50%	4.50%
Actual		12.30%	12.60%
Leverage Ratio:
Required		¥ 5,556	¥ 5,517
Required		3.00%	3.00%
Actual		¥ 8,191	¥ 8,199
Actual		4.42%	4.45%
Mizuho Trust & Banking Company Limited | Consolidated
Common Equity Tier 1 capital:
Required		¥ 96	¥ 95
Actual		510	500
Tier 1 capital:
Required		128	127
Actual		¥ 511	¥ 501
Required		6.00%	6.00%
Actual		23.99%	23.70%
Total risk-based capital:
Required		¥ 170	¥ 169
Actual		¥ 513	¥ 505
Required		8.00%	8.00%
Actual		24.11%	23.87%
Common Equity Tier 1 capital:
Required		4.50%	4.50%
Actual		23.96%	23.67%
Leverage Ratio:
Required		¥ 222	¥ 229
Required		3.00%	3.00%
Actual		¥ 511	¥ 501
Actual		6.90%	6.55%
Mizuho Trust & Banking Company Limited | Non-consolidated
Common Equity Tier 1 capital:
Required		¥ 95	¥ 94
Actual		500	494
Tier 1 capital:
Required		127	126
Actual		¥ 500	¥ 494
Required		6.00%	6.00%
Actual		23.64%	23.58%
Total risk-based capital:
Required		¥ 169	¥ 168
Actual		¥ 503	¥ 498
Required		8.00%	8.00%
Actual		23.76%	23.75%
Common Equity Tier 1 capital:
Required		4.50%	4.50%
Actual		23.64%	23.58%
Leverage Ratio:
Required		¥ 220	¥ 227
Required		3.00%	3.00%
Actual		¥ 500	¥ 494
Actual		6.82%	6.53%
[1]	The required ratios disclosed above, at March 31, 2019 and September 30, 2019, include the transitional capital conservation buffer of 2.5%, the countercyclical capital buffer of 0.05%, and the transitional additional loss absorbency requirements for global systemically important banks (“G-SIBs”) and domestic systemically important banks (“D-SIBs”) of 1.0%, which are all in addition to the regulatory minima. The respective required amounts are determined by applying the ratios to the sum of the risk weighted assets and certain other risk amounts.

Regulatory Matters (Capital A_2

Regulatory Matters (Capital Adequacy Ratios of MHFG, MHBK, and MHTB Calculated in Accordance with Japanese GAAP and Guidelines Established by Financial Services Agency) (Parenthetical) (Detail)	6 Months Ended	12 Months Ended
	Sep. 30, 2019	Mar. 31, 2019
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Capital conservation buffer	2.50%	2.50%
Additional loss absorbency requirements for G-SIBs and D-SIBs	1.00%	1.00%
Countercyclical capital buffer	0.05%	0.05%

Earnings Per Common Share (Comp

Earnings Per Common Share (Computation of Basic and Diluted Earnings Per Common Share) (Detail) - JPY (¥) ¥ / shares in Units, shares in Thousands, ¥ in Millions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Net income:
Net income attributable to MHFG common shareholders	¥ 212,984	¥ 285,270
Effect of dilutive securities
Net income attributable to common shareholders after assumed conversions	¥ 212,984	¥ 285,270
Shares:
Weighted average common shares outstanding	25,367,997	25,363,167
Effect of dilutive securities:
Stock options and the common shares of MHFG under the stock compensation programs	2,093	4,790
Weighted average common shares after assumed conversions	25,370,090	25,367,957
Earnings per common share:
Basic net income per common share	¥ 8.40	¥ 11.25
Diluted net income per common share	¥ 8.40	¥ 11.25

Income Taxes (Components of Inc

Income Taxes (Components of Income Tax Expense) (Detail) - JPY (¥) ¥ in Millions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Reconciliation of Provision of Income Taxes [Line Items]
Current tax expense	¥ 88,437	¥ 114,666
Deferred tax expense (benefit)	(5,317)	(28,961)
Total income tax expense	¥ 83,120	¥ 85,705

Income Taxes (Detailed Amounts

Income Taxes (Detailed Amounts of Tax Effects of Items Recorded Directly in Equity) (Detail) - JPY (¥) ¥ in Millions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Net unrealized gains (losses) on available-for-sale securities:
Unrealized gains (losses)	¥ 11,023	¥ (11,292)
Less: reclassification adjustments	(9,192)	(383)
Total	1,831	(11,675)
Pension liability adjustments:
Unrealized gains (losses)	(643)	(97)
Less: reclassification adjustments	(937)	(1,184)
Total	(1,580)	(1,281)
Own credit risk adjustments:
Unrealized gains (losses)	(43)	967
Less: reclassification adjustments	(588)	(9)
Total	(631)	958
Total tax effect before allocation to noncontrolling interests	¥ (380)	¥ (11,998)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - JPY (¥) ¥ in Millions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Income Taxes [Line Items]
Statutory tax rate	30.62%	30.62%
Effective tax rate	26.77%	20.52%
Net operating loss carryforwards	¥ 647,000
Unrecognized Tax Benefits	¥ 3,098

Pension and Other Employee Be_3

Pension and Other Employee Benefit Plans (Components of Net Periodic Costs of Severance Indemnities and Pension Plans) (Detail) - JPY (¥) ¥ in Millions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefits earned during the period	¥ 22,729	¥ 21,726
Interest costs on projected benefit obligations	2,666	3,331
Expected return on plan assets	(20,158)	(19,124)
Amortization of prior service benefits	19	76
Amortization of net actuarial loss (gain)	(3,064)	(3,942)
Special termination benefits	2,188	1,792
Net periodic benefit cost	¥ 4,380	¥ 3,859

Pension and Other Employee Be_4

Pension and Other Employee Benefit Plans - Additional Information (Detail) - JPY (¥) ¥ in Billions	6 Months Ended
	Sep. 30, 2019	Mar. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Pension plan, contribution expected to be paid during the next fiscal year		¥ 52
Total payment to pension plans	¥ 26
Additional contribution expected to be paid during remainder of fiscal year	¥ 26

Derivative Financial Instrume_3

Derivative Financial Instruments (Summary of Notional and Fair Value Amounts of Derivative Instruments Outstanding) (Detail) - JPY (¥) ¥ in Billions		Sep. 30, 2019	Mar. 31, 2019
Derivatives, Fair Value [Line Items]
Notional amount	[1]	¥ 1,282,481	¥ 1,227,208
Interest rate contracts
Derivatives, Fair Value [Line Items]
Notional amount	[1]	1,102,120	1,052,267
Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Notional amount	[1]	170,816	166,383
Equity-related contracts
Derivatives, Fair Value [Line Items]
Notional amount	[1]	6,197	5,181
Credit-related contracts
Derivatives, Fair Value [Line Items]
Notional amount	[1]	2,923	2,939
Other contracts
Derivatives, Fair Value [Line Items]
Notional amount	[1]	425	438
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative receivables	[2]	9,581	7,904
Fair value of derivative payables	[2]	9,206	7,541
Not Designated as Hedging Instrument | Interest rate contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative receivables	[2]	7,054	5,786
Fair value of derivative payables	[2]	6,788	5,610
Not Designated as Hedging Instrument | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative receivables	[2]	2,342	1,959
Fair value of derivative payables	[2]	2,202	1,758
Not Designated as Hedging Instrument | Equity-related contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative receivables	[2]	148	125
Fair value of derivative payables	[2]	176	142
Not Designated as Hedging Instrument | Credit-related contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative receivables	[2]	21	18
Fair value of derivative payables	[2]	25	17
Not Designated as Hedging Instrument | Other contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative receivables	[2]	16	16
Fair value of derivative payables	[2]	¥ 15	¥ 14
[1]	Notional amount includes the sum of gross long and gross short third-party contracts.
[2]	Derivative receivables and payables are recorded in Trading account assets and Trading account liabilities, respectively.

Derivative Financial Instrume_4

Derivative Financial Instruments - Additional Information (Detail) - JPY (¥) ¥ in Millions	Sep. 30, 2019	Mar. 31, 2019
Derivative [Line Items]
Cash collateral provided and not offset against derivative positions and included in Other assets	¥ 1,008,596	¥ 856,439
Cash collateral accepted and not offset against derivative positions and included in Other liabilities	¥ 533,308	¥ 589,411

Derivative Financial Instrume_5

Derivative Financial Instruments (Summary of Gains and Losses Information Related to Net Investment Hedges) (Detail) - JPY (¥) ¥ in Millions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in OCI	¥ (1,044)	¥ 1,906
Financial instruments hedging foreign exchange risk
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in OCI	¥ (1,044)	¥ 1,906

Derivative Financial Instrume_6

Derivative Financial Instruments (Summary of Gains and Losses Information Related to Net Investment Hedges) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions	Sep. 30, 2019	Sep. 30, 2018
Financial instruments hedging foreign exchange risk
Derivative Instruments, Gain (Loss) [Line Items]
Accumulated other comprehensive income reclassified to earnings	¥ (260)	¥ 186

Derivative Financial Instrume_7

Derivative Financial Instruments (Summary of Gains and Losses on Derivatives not Designated or Qualifying as Hedges) (Detail) - JPY (¥) ¥ in Millions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		¥ 174,483	¥ (29,006)
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		210,909	(75,324)
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		(30,736)	26,706
Equity-related contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		(494)	20,432
Credit-related contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income	[1]	(3,546)	(35)
Other contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		¥ (1,650)	¥ (785)
[1]	Amounts include the net gains (losses) of ¥(215) million and ¥(426) million on the credit derivatives economically managing the credit risk of loans during the six months ended September 30, 2018 and 2019, respectively.

Derivative Financial Instrume_8

Derivative Financial Instruments (Summary of Gains and Losses on Derivatives not Designated or Qualifying as Hedges) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		¥ 174,483	¥ (29,006)
Credit-related contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income	[1]	(3,546)	(35)
Credit-related contracts | Loans related to credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		¥ (426)	¥ (215)
[1]	Amounts include the net gains (losses) of ¥(215) million and ¥(426) million on the credit derivatives economically managing the credit risk of loans during the six months ended September 30, 2018 and 2019, respectively.

Derivative Financial Instrume_9

Derivative Financial Instruments (Summary of Notional and Fair Value Amounts of Credit Derivatives) (Detail) - JPY (¥) ¥ in Billions	Sep. 30, 2019	Mar. 31, 2019
Credit protection written
Credit Derivatives [Line Items]
Notional amount	¥ 1,297	¥ 1,465
Fair value	18	15
Credit protection written | Investment grade
Credit Derivatives [Line Items]
Notional amount	1,072	1,266
Fair value	13	12
Credit protection written | Non-investment grade
Credit Derivatives [Line Items]
Notional amount	225	199
Fair value	5	3
Credit protection purchased
Credit Derivatives [Line Items]
Notional amount	1,788	1,628
Fair value	¥ (22)	¥ (14)

Derivative Financial Instrum_10

Derivative Financial Instruments (Maximum Potential Amount of Future Payments for Credit Protection Written by Expiration Period) (Detail) - JPY (¥) ¥ in Billions	Sep. 30, 2019	Mar. 31, 2019
Credit Derivatives [Line Items]
Maximum payout/Notional amount	¥ 1,297	¥ 1,465
One year or less
Credit Derivatives [Line Items]
Maximum payout/Notional amount	293	326
After one year through five years
Credit Derivatives [Line Items]
Maximum payout/Notional amount	902	1,057
After five years
Credit Derivatives [Line Items]
Maximum payout/Notional amount	¥ 102	¥ 82

Derivative Financial Instrum_11

Derivative Financial Instruments (Quantitative Information about Derivative Instruments with Credit-risk-related Contingent Features) (Detail) - JPY (¥) ¥ in Billions	Sep. 30, 2019	Mar. 31, 2019
Credit Derivatives [Line Items]
Aggregate fair value of derivative instruments with credit-risk-related contingent features in net liability positions	¥ 695	¥ 511
Collateral provided to counterparties in the normal course of business	679	489
Amount required to be posted as collateral or settled immediately if credit-risk-related contingent features were triggered	¥ 16	¥ 22

Commitments and Contingencies_2

Commitments and Contingencies (Summary of Maximum Potential Amount of Future Payments under Guarantees) (Detail) - JPY (¥) ¥ in Billions	Sep. 30, 2019	Mar. 31, 2019
Performance guarantees
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	¥ 2,182	¥ 2,307
Guarantees on loans
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	246	289
Guarantees on securities
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	110	145
Other guarantees
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	2,291	2,324
Guarantees for repayment of trust principal
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	63	65
Liabilities of trust accounts
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	376	362
Derivative financial instruments
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	¥ 19,421	¥ 14,170

Commitments and Contingencies_3

Commitments and Contingencies (Summary of Maximum Potential Amount of Future Payments of Certain Guarantees Classified Based on Internal Ratings) (Detail) - Performance guarantees, Guarantees on loans, Guarantees on securities and Other guarantees - JPY (¥) ¥ in Billions	Sep. 30, 2019	Mar. 31, 2019
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	¥ 4,829	¥ 5,065
Investment grade
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	3,909	4,124
Non-investment grade
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	¥ 920	¥ 941

Commitments and Contingencies_4

Commitments and Contingencies (Summary of Contractual Amounts with Regard to Undrawn Commitments) (Detail) - JPY (¥) ¥ in Billions		Sep. 30, 2019	Mar. 31, 2019
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments, contractual amounts of the undrawn commitments		¥ 78,893	¥ 77,635
Commitments to Extend Credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments, contractual amounts of the undrawn commitments	[1]	78,075	76,857
Commercial letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments, contractual amounts of the undrawn commitments		¥ 818	¥ 778
[1]	Commitments to extend credit include commitments to invest in securities.

Commitments and contingencies -

Commitments and contingencies - Schedule Of Balance Sheet Information Related to Operating Lease (Detail) ¥ in Millions	Sep. 30, 2019JPY (¥)
Commitments and Contingencies Disclosure [Abstract]
ROU assets	¥ 647,185	[1]
Lease liabilities	¥ 656,409	[1]
Weighted average:
Remaining lease term	15 years 9 months 18 days
Discount rate	0.55%
[1]	ROU assets and lease liabilities were recognized in connection with the adoption of ASU No.2016-02 on April 1, 2019. See Note 1 “Basis of presentation” and Note 2 “Recently issued accounting pronouncements” for further information.

Commitments and contingencies_5

Commitments and contingencies - Schedule Of Operating Lease Cost And Supplemental Cash Flow Information (Detail) ¥ in Millions	6 Months Ended
	Sep. 30, 2019JPY (¥)
Commitments and Contingencies Disclosure [Abstract]
Lease cost	¥ 62,003	[1]
ROU assets obtained in exchange for new lease liabilities	45,904
Operating cash flows	¥ 51,120
[1]	Lease cost for operating leases are included in Occupancy expenses on the consolidated statements of income.

Commitments and contingencies_6

Commitments and contingencies - Schedule Of Future Lease Payments Under Operating Leases (Detail) ¥ in Millions	Sep. 30, 2019JPY (¥)
Commitments and Contingencies Disclosure [Abstract]
2020 (excluding six months ended September 30, 2019)	¥ 49,182
2021	84,578
2022	64,138
2023	52,167
2024	46,829
2025 and thereafter	386,291
Total lease payments	683,185
Amount representing interest	26,776
Total lease liabilities for operating leases	¥ 656,409	[1]
[1]	ROU assets and lease liabilities were recognized in connection with the adoption of ASU No.2016-02 on April 1, 2019. See Note 1 “Basis of presentation” and Note 2 “Recently issued accounting pronouncements” for further information.

Variable Interest Entities an_3

Variable Interest Entities and Securitizations (Consolidated Assets of Consolidated VIEs as well as Total Assets and Maximum Exposure to Loss for Significant Unconsolidated VIEs) (Detail) - JPY (¥) ¥ in Billions	Sep. 30, 2019	Mar. 31, 2019
Variable Interest Entity [Line Items]
Consolidated VIEs- Consolidated assets	¥ 5,939	¥ 6,048
Significant unconsolidated VIEs- Total assets	1,670	1,350
Significant unconsolidated VIEs- Maximum exposure to loss	485	418
Asset-backed commercial paper/loan programs
Variable Interest Entity [Line Items]
Consolidated VIEs- Consolidated assets	2,325	2,249
Asset-backed securitizations
Variable Interest Entity [Line Items]
Consolidated VIEs- Consolidated assets	544	571
Significant unconsolidated VIEs- Total assets	70	70
Significant unconsolidated VIEs- Maximum exposure to loss	9	8
Investments in securitization products
Variable Interest Entity [Line Items]
Consolidated VIEs- Consolidated assets	371	372
Investment funds
Variable Interest Entity [Line Items]
Consolidated VIEs- Consolidated assets	2,680	2,836
Significant unconsolidated VIEs- Total assets	1,600	1,280
Significant unconsolidated VIEs- Maximum exposure to loss	476	410
Trust arrangements and other
Variable Interest Entity [Line Items]
Consolidated VIEs- Consolidated assets	¥ 19	¥ 20

Variable Interest Entities an_4

Variable Interest Entities and Securitizations (Carrying Amounts and Classification of Assets and Liabilities on Consolidated Balance Sheets that Relate to Variable Interests in Significant Unconsolidated VIEs) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Assets on balance sheets related to unconsolidated VIEs:
Trading account assets		¥ 24,950,040	¥ 21,018,230
Loans		83,564,769	82,492,742
Total assets		201,772,463	197,611,195
Liabilities on balance sheets and maximum exposure to loss related to unconsolidated VIEs:
Payables under securities lending transactions		1,857,118	1,797,737
Trading account liabilities		11,973,917	10,120,968
Total		192,285,890	188,109,702
Maximum exposure to loss		485,000	418,000
Unconsolidated VIEs
Assets on balance sheets related to unconsolidated VIEs:
Trading account assets		107,000	104,000
Investments		171,000	168,000
Loans		122,000	71,000
Total assets		400,000	343,000
Liabilities on balance sheets and maximum exposure to loss related to unconsolidated VIEs:
Payables under securities lending transactions		47,000	47,000
Trading account liabilities		1,000	1,000
Total		48,000	48,000
Maximum exposure to loss	[1]	¥ 485,000	¥ 418,000
[1]	This represents the maximum amount the Group could possibly be required to record in its consolidated statements of income associated with on-balance-sheet exposures and off-balance-sheet liabilities such as undrawn commitments.

Variable Interest Entities an_5

Variable Interest Entities and Securitizations - Additional Information (Detail) - JPY (¥) ¥ in Millions	Sep. 30, 2019	Mar. 31, 2019
Variable Interest Entity [Line Items]
Long-term debt	¥ 10,427,340	¥ 11,529,400
Debt Instrument [Member]
Variable Interest Entity [Line Items]
Long-term debt	354,000	681,000
Assets associated with securitization transactions
Variable Interest Entity [Line Items]
Transferred assets continue to be carried on the consolidated balance sheets	188,000	207,000
Assets associated with loan participation transactions
Variable Interest Entity [Line Items]
Transferred assets continue to be carried on the consolidated balance sheets	¥ 122,000	¥ 143,000

Summary of Noninterest Income (

Summary of Noninterest Income (Detail) - JPY (¥) ¥ in Millions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Fee and commission income		¥ 403,992	¥ 413,727
Foreign exchange gains (losses)—net	[1]	27,923	44,718
Trading account gains (losses)—net	[2]	395,405	64,956
Investment gains (losses)—net:
Debt securities	[1]	31,092	2,485
Equity securities	[1]	(126,648)	306,788
Equity in earnings (losses) of equity method investees—net	[1]	22,066	22,627
Gains on disposal of premises and equipment	[1]	1,693	4,305
Other noninterest income	[2]	34,839	48,950
Total noninterest income		790,362	908,556
Securities related business
Disaggregation of Revenue [Line Items]
Fee and commission income	[3]	64,498	79,138
Banking
Disaggregation of Revenue [Line Items]
Fee and commission income	[2]	76,179	70,647
Correspondent clearing
Disaggregation of Revenue [Line Items]
Fee and commission income	[3]	56,075	55,078
Investment advisory, management and administrative service
Disaggregation of Revenue [Line Items]
Fee and commission income	[3]	48,291	49,818
Fiduciary and trust
Disaggregation of Revenue [Line Items]
Fee and commission income	[3]	56,459	57,372
Agency business
Disaggregation of Revenue [Line Items]
Fee and commission income	[3]	15,152	19,509
Guarantee related business
Disaggregation of Revenue [Line Items]
Fee and commission income	[1]	13,898	14,234
Financial service, other
Disaggregation of Revenue [Line Items]
Fee and commission income	[3]	73,440	67,931
Financial service
Disaggregation of Revenue [Line Items]
Fee and commission income		¥ 403,992	¥ 413,727
[1]	These amounts are revenues from contracts that do not meet the scope of ASC 606.
[2]	Part of these amounts are considered to be revenues from contracts that are within the scope of ASC 606.
[3]	These amounts are revenues from contracts within the scope of ASC 606, “Revenue from contracts with customers” (“ASC 606”).

Noninterest Income - Additional

Noninterest Income - Additional Information (Detail) - JPY (¥) ¥ in Millions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Other Revenues [Line Items]
Lending fees		¥ 69,000
Trust fees		25,000	¥ 26,000
Fees related to trust business		31,000	31,000
Trading account gains (losses)—net	[1]	395,405	64,956
Other noninterest income	[1]	34,839	48,950
Revenue from contracts with customers ("ASC 606")
Other Revenues [Line Items]
Deposit fees		7,000
Trading account gains (losses)—net		33,000	31,000
Other noninterest income		¥ 12,000	¥ 14,000
[1]	Part of these amounts are considered to be revenues from contracts that are within the scope of ASC 606.

Fair Value - Additional Informa

Fair Value - Additional Information (Detail) - JPY (¥) ¥ in Billions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2019
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Carrying amounts of other equity interests of which fair value is not readily determinable	¥ 227		¥ 212
Senior borrowings and bonds
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
The differences between the aggregate fair value and aggregate unpaid principal balance of the notes for which the fair value option has been elected	11		¥ 21
Net unrealized gains (losses) resulting from changes in fair values of the notes	¥ 2	¥ 8
Investment funds
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Underlying assets, estimated remaining liquidation period	10 years
Long-term debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of liabilities transferred out of Level 3	¥ 6
Fair value of liabilities transferred into Level 3	¥ 17	2
Available-for-sale securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of assets transferred into Level 3		¥ 61

Fair Value (Summary of Assets a

Fair Value (Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis, Including Fair Value Option Elected) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Assets:
Available-for-sale securities		¥ 17,690,583	¥ 18,133,916
Liabilities:
Long-term debt		2,662,041	2,433,294
Fair Value, Measurements, Recurring
Assets:
Equity securities with readily determinable fair values		3,473,000	3,768,000
Equity securities measured at net asset value	[1]	61,000	53,000
Other investments		36,000	35,000
Total assets measured at fair value		46,210,000	43,007,000
Liabilities:
Trading securities sold, not yet purchased		2,767,000	2,580,000
Long-term debt	[2]	2,662,000	2,433,000
Total liabilities measured at fair value		14,635,000	12,554,000
Fair Value, Measurements, Recurring | Trading Account Asset
Assets:
Securities measured at net asset value	[1],[3]	1,001,000	631,000
Fair Value, Measurements, Recurring | Interest rate contracts
Assets:
Assets, derivatives		7,054,000	5,786,000
Liabilities:
Liabilities, derivatives		6,788,000	5,610,000
Fair Value, Measurements, Recurring | Foreign exchange contracts
Assets:
Assets, derivatives		2,342,000	1,959,000
Liabilities:
Liabilities, derivatives		2,202,000	1,758,000
Fair Value, Measurements, Recurring | Equity-related contracts
Assets:
Assets, derivatives		148,000	125,000
Liabilities:
Liabilities, derivatives		176,000	142,000
Fair Value, Measurements, Recurring | Credit-related contracts
Assets:
Assets, derivatives		21,000	18,000
Liabilities:
Liabilities, derivatives		25,000	17,000
Fair Value, Measurements, Recurring | Other contracts
Assets:
Assets, derivatives		16,000	16,000
Liabilities:
Liabilities, derivatives		15,000	14,000
Fair Value, Measurements, Recurring | Japanese government bonds
Assets:
Assets, trading securities	[3]	2,534,000	1,862,000
Available-for-sale securities		11,427,000	11,897,000
Fair Value, Measurements, Recurring | Japanese local government bonds
Assets:
Assets, trading securities	[3]	123,000	134,000
Available-for-sale securities		235,000	210,000
Fair Value, Measurements, Recurring | U.S. Treasury bonds and federal agency securities
Assets:
Assets, trading securities	[3]	2,312,000	1,207,000
Available-for-sale securities		1,001,000	1,009,000
Fair Value, Measurements, Recurring | Other foreign government bonds
Assets:
Assets, trading securities	[3]	2,263,000	2,970,000
Available-for-sale securities		1,332,000	1,342,000
Fair Value, Measurements, Recurring | Agency mortgage-backed securities
Assets:
Assets, trading securities	[3]	1,962,000	1,041,000
Available-for-sale securities		512,000	544,000
Fair Value, Measurements, Recurring | Residential mortgage-backed securities
Assets:
Assets, trading securities	[3]	10,000	11,000
Available-for-sale securities		87,000	101,000
Fair Value, Measurements, Recurring | Commercial mortgage-backed securities
Assets:
Available-for-sale securities		549,000	500,000
Fair Value, Measurements, Recurring | Certificates of deposit and commercial paper
Assets:
Assets, trading securities	[3]	1,316,000	1,047,000
Fair Value, Measurements, Recurring | Corporate bonds and other debt securities
Assets:
Assets, trading securities	[3],[4]	2,737,000	2,886,000
Fair Value, Measurements, Recurring | Equity securities
Assets:
Assets, trading securities	[3]	1,111,000	1,325,000
Fair Value, Measurements, Recurring | Japanese corporate bonds and other debt securities
Assets:
Available-for-sale securities		1,803,000	1,749,000
Fair Value, Measurements, Recurring | Foreign corporate bonds and other debt securities
Assets:
Available-for-sale securities		744,000	781,000
Fair Value, Measurements, Recurring | Level 1
Assets:
Equity securities with readily determinable fair values		3,350,000	3,633,000
Total assets measured at fair value		22,845,000	22,753,000
Liabilities:
Trading securities sold, not yet purchased		2,571,000	2,380,000
Total liabilities measured at fair value		2,732,000	2,512,000
Fair Value, Measurements, Recurring | Level 1 | Interest rate contracts
Assets:
Assets, derivatives		49,000	36,000
Liabilities:
Liabilities, derivatives		49,000	38,000
Fair Value, Measurements, Recurring | Level 1 | Foreign exchange contracts
Assets:
Assets, derivatives		7,000	9,000
Liabilities:
Liabilities, derivatives		7,000	11,000
Fair Value, Measurements, Recurring | Level 1 | Equity-related contracts
Assets:
Assets, derivatives		61,000	58,000
Liabilities:
Liabilities, derivatives		104,000	82,000
Fair Value, Measurements, Recurring | Level 1 | Other contracts
Assets:
Assets, derivatives		1,000	2,000
Liabilities:
Liabilities, derivatives		1,000	1,000
Fair Value, Measurements, Recurring | Level 1 | Japanese government bonds
Assets:
Assets, trading securities	[3]	2,506,000	1,829,000
Available-for-sale securities		10,600,000	10,902,000
Fair Value, Measurements, Recurring | Level 1 | U.S. Treasury bonds and federal agency securities
Assets:
Assets, trading securities	[3]	2,089,000	1,069,000
Available-for-sale securities		1,001,000	1,009,000
Fair Value, Measurements, Recurring | Level 1 | Other foreign government bonds
Assets:
Assets, trading securities	[3]	1,638,000	2,417,000
Available-for-sale securities		421,000	456,000
Fair Value, Measurements, Recurring | Level 1 | Corporate bonds and other debt securities
Assets:
Assets, trading securities	[3],[4]	41,000	36,000
Fair Value, Measurements, Recurring | Level 1 | Equity securities
Assets:
Assets, trading securities	[3]	1,081,000	1,297,000
Fair Value, Measurements, Recurring | Level 2
Assets:
Equity securities with readily determinable fair values		123,000	135,000
Total assets measured at fair value		20,162,000	17,629,000
Liabilities:
Trading securities sold, not yet purchased		196,000	199,000
Long-term debt	[2]	2,016,000	1,778,000
Total liabilities measured at fair value		11,223,000	9,358,000
Fair Value, Measurements, Recurring | Level 2 | Interest rate contracts
Assets:
Assets, derivatives		6,997,000	5,729,000
Liabilities:
Liabilities, derivatives		6,736,000	5,564,000
Fair Value, Measurements, Recurring | Level 2 | Foreign exchange contracts
Assets:
Assets, derivatives		2,324,000	1,927,000
Liabilities:
Liabilities, derivatives		2,194,000	1,746,000
Fair Value, Measurements, Recurring | Level 2 | Equity-related contracts
Assets:
Assets, derivatives		75,000	63,000
Liabilities:
Liabilities, derivatives		53,000	51,000
Fair Value, Measurements, Recurring | Level 2 | Credit-related contracts
Assets:
Assets, derivatives		18,000	16,000
Liabilities:
Liabilities, derivatives		23,000	16,000
Fair Value, Measurements, Recurring | Level 2 | Other contracts
Assets:
Assets, derivatives		5,000	4,000
Liabilities:
Liabilities, derivatives		5,000	4,000
Fair Value, Measurements, Recurring | Level 2 | Japanese government bonds
Assets:
Assets, trading securities	[3]	28,000	33,000
Available-for-sale securities		827,000	995,000
Fair Value, Measurements, Recurring | Level 2 | Japanese local government bonds
Assets:
Assets, trading securities	[3]	123,000	134,000
Available-for-sale securities		235,000	210,000
Fair Value, Measurements, Recurring | Level 2 | U.S. Treasury bonds and federal agency securities
Assets:
Assets, trading securities	[3]	223,000	138,000
Fair Value, Measurements, Recurring | Level 2 | Other foreign government bonds
Assets:
Assets, trading securities	[3]	625,000	553,000
Available-for-sale securities		911,000	886,000
Fair Value, Measurements, Recurring | Level 2 | Agency mortgage-backed securities
Assets:
Assets, trading securities	[3]	1,962,000	1,041,000
Available-for-sale securities		512,000	544,000
Fair Value, Measurements, Recurring | Level 2 | Residential mortgage-backed securities
Assets:
Available-for-sale securities		54,000	61,000
Fair Value, Measurements, Recurring | Level 2 | Certificates of deposit and commercial paper
Assets:
Assets, trading securities	[3]	1,316,000	1,047,000
Fair Value, Measurements, Recurring | Level 2 | Corporate bonds and other debt securities
Assets:
Assets, trading securities	[3],[4]	1,559,000	1,806,000
Fair Value, Measurements, Recurring | Level 2 | Japanese corporate bonds and other debt securities
Assets:
Available-for-sale securities		1,634,000	1,629,000
Fair Value, Measurements, Recurring | Level 2 | Foreign corporate bonds and other debt securities
Assets:
Available-for-sale securities		611,000	678,000
Fair Value, Measurements, Recurring | Level 3
Assets:
Other investments		36,000	35,000
Total assets measured at fair value		2,141,000	1,941,000
Liabilities:
Trading securities sold, not yet purchased			1,000
Long-term debt	[2]	646,000	655,000
Total liabilities measured at fair value		680,000	684,000
Fair Value, Measurements, Recurring | Level 3 | Interest rate contracts
Assets:
Assets, derivatives		8,000	21,000
Liabilities:
Liabilities, derivatives		3,000	8,000
Fair Value, Measurements, Recurring | Level 3 | Foreign exchange contracts
Assets:
Assets, derivatives		11,000	23,000
Liabilities:
Liabilities, derivatives		1,000	1,000
Fair Value, Measurements, Recurring | Level 3 | Equity-related contracts
Assets:
Assets, derivatives		12,000	4,000
Liabilities:
Liabilities, derivatives		19,000	9,000
Fair Value, Measurements, Recurring | Level 3 | Credit-related contracts
Assets:
Assets, derivatives		3,000	2,000
Liabilities:
Liabilities, derivatives		2,000	1,000
Fair Value, Measurements, Recurring | Level 3 | Other contracts
Assets:
Assets, derivatives		10,000	10,000
Liabilities:
Liabilities, derivatives		9,000	9,000
Fair Value, Measurements, Recurring | Level 3 | Residential mortgage-backed securities
Assets:
Assets, trading securities	[3]	10,000	11,000
Available-for-sale securities		33,000	40,000
Fair Value, Measurements, Recurring | Level 3 | Commercial mortgage-backed securities
Assets:
Available-for-sale securities		549,000	500,000
Fair Value, Measurements, Recurring | Level 3 | Corporate bonds and other debt securities
Assets:
Assets, trading securities	[3],[4]	1,137,000	1,044,000
Fair Value, Measurements, Recurring | Level 3 | Equity securities
Assets:
Assets, trading securities	[3]	30,000	28,000
Fair Value, Measurements, Recurring | Level 3 | Japanese corporate bonds and other debt securities
Assets:
Available-for-sale securities		169,000	120,000
Fair Value, Measurements, Recurring | Level 3 | Foreign corporate bonds and other debt securities
Assets:
Available-for-sale securities		¥ 133,000	¥ 103,000
[1]	In accordance with ASC 820, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented for these classes of assets are intended to permit the reconciliation of the fair value hierarchy to the amounts presented in the statements of financial position. The amounts of unfunded commitments related to these investments at March 31, 2019 and September 30, 2019 were ¥37 billion and ¥41 billion, respectively.
[2]	Amounts represent items for which the Group elected the fair value option or for which it applied the practicability exception.
[3]	Trading securities include foreign currency denominated securities for which the MHFG Group elected the fair value option.
[4]	The amount includes CLO and convertible bonds, which are classified in Level 3.

Fair Value (Summary of Assets_2

Fair Value (Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis, Including Fair Value Option Elected) (Parenthetical) (Detail) - JPY (¥) ¥ in Billions	Sep. 30, 2019	Mar. 31, 2019
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unfunded commitments	¥ 41	¥ 37

Fair Value (Reconciliation for

Fair Value (Reconciliation for All Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)) (Detail) - JPY (¥) ¥ in Billions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Other investments
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		¥ 35	¥ 38
Gains (losses) in Earnings	[1]	1	1
Purchases		10	13
Issuances			0
Settlements		(10)	(11)
Ending Balance		36	41
Change in unrealized gain (losses) still held	[2]	2	2
Trading securities sold, not yet purchased
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		1	4
Gains (losses) in Earnings	[3]		1
Purchases		(9)	(30)
Sales		8	29
Ending Balance			2
Long-term debt
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		655	561
Gains (losses) in Earnings	[4]	(6)	2
Gains (losses) in OCI	[5]		3
Transfers into Level 3		17	2
Transfers out of level 3		(6)
Issuances		108	85
Settlements		(134)	(31)
Ending Balance		646	612
Change in unrealized gain (losses) still held	[2]	(10)	4
Trading securities | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		11	12
Issuances			0
Settlements		(1)
Ending Balance		10	12
Trading securities | Corporate bonds and other debt securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		1,044	1,013
Gains (losses) in Earnings	[3]	(15)	31
Purchases		338	457
Sales		(105)	(242)
Issuances			0
Settlements		(125)	(154)
Ending Balance		1,137	1,105
Change in unrealized gain (losses) still held	[2]	(14)	35
Trading securities | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		28	23
Gains (losses) in Earnings	[3]	2	2
Purchases		1	5
Sales			(1)
Issuances			0
Settlements		(1)
Ending Balance		30	29
Derivative financial instruments assets | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	[6]	13	21
Gains (losses) in Earnings	[3],[6]	(9)	1
Issuances	[6]		0
Settlements	[6]	1	1
Ending Balance	[6]	5	23
Change in unrealized gain (losses) still held	[2],[6]	(8)	2
Derivative financial instruments assets | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	[6]	22	12
Gains (losses) in Earnings	[3],[6]	(10)	15
Issuances	[6]		0
Settlements	[6]	(2)	(2)
Ending Balance	[6]	10	25
Change in unrealized gain (losses) still held	[2],[6]	(9)	17
Derivative financial instruments assets | Equity-related contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	[6]	(5)	4
Gains (losses) in Earnings	[3],[6]	1	(4)
Issuances	[6]		0
Settlements	[6]	(3)	14
Ending Balance	[6]	(7)	14
Change in unrealized gain (losses) still held	[2],[6]	2
Derivative financial instruments assets | Other contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	[6]	1
Ending Balance	[6]	1
Derivative financial instruments assets | Credit Related Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	[6]	1	1
Gains (losses) in Earnings	[3],[6]		(3)
Issuances	[6]		0
Settlements	[6]		2
Ending Balance	[6]	1
Available-for-sale securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers into Level 3			61
Available-for-sale securities | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		40	54
Issuances			0
Settlements		(7)	(8)
Ending Balance		33	46
Available-for-sale securities | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		500	441
Gains (losses) in OCI	[5]	1
Purchases		89	57
Sales		(35)	(28)
Issuances			0
Settlements		(6)	(1)
Ending Balance		549	469
Available-for-sale securities | Japanese corporate bonds and other debt securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		120	163
Gains (losses) in Earnings	[1]	1	10
Gains (losses) in OCI	[5]	4	(8)
Purchases		97	7
Sales			(7)
Issuances			0
Settlements		(53)	(9)
Ending Balance		169	156
Change in unrealized gain (losses) still held	[2]		10
Available-for-sale securities | Foreign corporate bonds and other debt securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		103	80
Gains (losses) in OCI	[5]	(5)
Transfers into Level 3			61
Purchases		38	4
Issuances			0
Settlements		(3)	0
Ending Balance		¥ 133	¥ 145
[1]	Gains (losses) in Earnings are reported in Investment gains (losses)—net.
[2]	Amounts represent total gains or losses recognized in earnings during the period. These gains or losses were attributable to the change in fair value relating to assets and liabilities classified as Level 3 that were still held at September 30, 2018 and 2019.
[3]	Gains (losses) in Earnings are reported in Trading account gains (losses)—net, Foreign exchange gains (losses)—net or Other noninterest income (expenses).
[4]	Gains (losses) in Earnings are reported in Other noninterest income (expenses).
[5]	Gains (losses) in OCI are reported in Other comprehensive income (loss).
[6]	Total Level 3 derivative exposures have been netted on the table for presentation purposes only.

Fair Value (Quantitative Inform

Fair Value (Quantitative Information about Significant Unobservable Inputs Related to Material Classes of Level 3 Assets and Liabilities) (Detail) ¥ in Millions		Sep. 30, 2019JPY (¥)BasisPoint	Mar. 31, 2019JPY (¥)BasisPoint
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt | ¥		¥ 2,662,041	¥ 2,433,294
Available For Sale And Trading Securities | Residential mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities | ¥		43,000	51,000
Available For Sale And Trading Securities | Commercial mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities | ¥		549,000	500,000
Available For Sale And Trading Securities | Corporate bonds and other debt securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities | ¥		1,439,000	1,267,000
Derivative Financial Instruments | Interest rate contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments | ¥		5,000	13,000
Derivative Financial Instruments | Foreign exchange contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments | ¥		10,000	22,000
Derivative Financial Instruments | Equity-related contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments | ¥		(7,000)	(5,000)
Derivative Financial Instruments | Credit-related contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments | ¥		1,000	1,000
Long-term debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt | ¥		¥ 646,000	¥ 655,000
Measurement Input, Default Rate [Member] | Derivative Financial Instruments | Interest rate contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1],[2]	0.63	0.63
Minimum | Measurement Input, Prepayment Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		0.04	0.04
Minimum | Measurement Input, Prepayment Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3]	0.16	0.22
Minimum | Measurement Input, Default Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		0	0
Minimum | Measurement Input, Default Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3]	0	0.02
Minimum | Measurement Input, Default Rate [Member] | Derivative Financial Instruments | Interest rate contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1],[2]	0	0
Minimum | Measurement Input, Default Rate [Member] | Derivative Financial Instruments | Foreign exchange contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1],[2]	0	0
Minimum | Measurement Input, Default Rate [Member] | Derivative Financial Instruments | Credit-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0	0
Minimum | Measurement Input, Default Rate [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0	0
Minimum | Measurement Input Recovery Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		1	1
Minimum | Measurement Input Recovery Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3]	0.40	0.69
Minimum | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		10	18
Minimum | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Commercial mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		7	9
Minimum | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3]	41	48
Minimum | Measurement Input Discount Rate1 [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[4]	2	4
Minimum | Measurement Input, IR - IR correlation [Member] | Derivative Financial Instruments | Interest rate contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.23	0.23
Minimum | Measurement Input, IR - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.23	0.23
Minimum | Measurement Input, FX - IR correlation [Member] | Derivative Financial Instruments | Foreign exchange contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	(0.19)	0.09
Minimum | Measurement Input, FX - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.24	0.09
Minimum | Measurement Input, FX - FX correlation [Member] | Derivative Financial Instruments | Foreign exchange contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.61	0.63
Minimum | Measurement Input, FX - FX correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.61	0.63
Minimum | Measurement Input, Equity - IR correlation [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.25	0.25
Minimum | Measurement Input, Equity - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.25	0.25
Minimum | Measurement Input, Equity - FX correlation [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.70
Minimum | Measurement Input, Equity - FX correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0	0.55
Minimum | Measurement Input, Equity volatility [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.06	0.05
Minimum | Measurement Input, Equity volatility [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.06	0.05
Minimum | Measurement Input, Credit correlation [Member] | Derivative Financial Instruments | Credit-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.30	0.29
Minimum | Measurement Input, Credit correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.15	0.2
Minimum | Measurement Input, Equity correlation [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.29	0.4
Minimum | Measurement Input, Equity correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.16	0.12
Maximum | Measurement Input, Prepayment Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		0.18	0.19
Maximum | Measurement Input, Prepayment Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3]	0.17	0.22
Maximum | Measurement Input, Default Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		0.01	0.01
Maximum | Measurement Input, Default Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3]	0.02	0.02
Maximum | Measurement Input, Default Rate [Member] | Derivative Financial Instruments | Interest rate contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1],[2]	0.63	0.63
Maximum | Measurement Input, Default Rate [Member] | Derivative Financial Instruments | Foreign exchange contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1],[2]	0.63	0.63
Maximum | Measurement Input, Default Rate [Member] | Derivative Financial Instruments | Credit-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.09	0.05
Maximum | Measurement Input, Default Rate [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.04	0.04
Maximum | Measurement Input Recovery Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		1	1
Maximum | Measurement Input Recovery Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3]	0.70	0.69
Maximum | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		170	170
Maximum | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Commercial mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		161	161
Maximum | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3]	1,193	1,173
Maximum | Measurement Input Discount Rate1 [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[4]	630	1,063
Maximum | Measurement Input, IR - IR correlation [Member] | Derivative Financial Instruments | Interest rate contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	1	1
Maximum | Measurement Input, IR - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	1	1
Maximum | Measurement Input, FX - IR correlation [Member] | Derivative Financial Instruments | Foreign exchange contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.55	0.55
Maximum | Measurement Input, FX - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.55	0.55
Maximum | Measurement Input, FX - FX correlation [Member] | Derivative Financial Instruments | Foreign exchange contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.61	0.63
Maximum | Measurement Input, FX - FX correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.61	0.63
Maximum | Measurement Input, Equity - IR correlation [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.25	0.25
Maximum | Measurement Input, Equity - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.25	0.25
Maximum | Measurement Input, Equity - FX correlation [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.70
Maximum | Measurement Input, Equity - FX correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.70	0.88
Maximum | Measurement Input, Equity volatility [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	0.61	0.36
Maximum | Measurement Input, Equity volatility [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	0.61	0.49
Maximum | Measurement Input, Credit correlation [Member] | Derivative Financial Instruments | Credit-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	1	1
Maximum | Measurement Input, Credit correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	1	1
Maximum | Measurement Input, Equity correlation [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[1]	1	1
Maximum | Measurement Input, Equity correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[1]	1	1
Weighted Average | Measurement Input, Prepayment Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[5]	0.07	0.08
Weighted Average | Measurement Input, Prepayment Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3],[5]	0.16	0.22
Weighted Average | Measurement Input, Default Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[5]	0	0
Weighted Average | Measurement Input, Default Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3],[5]	0.02	0.02
Weighted Average | Measurement Input Recovery Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[5]	1	1
Weighted Average | Measurement Input Recovery Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3],[5]	0.69	0.69
Weighted Average | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[5]	51	51
Weighted Average | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Commercial mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[5]	23	24
Weighted Average | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3],[5]	127	134
Weighted Average | Measurement Input Discount Rate1 [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[4],[5]	51	295
[1]	Internal valuation model includes discounted cash flow models and the Black-Scholes option pricing model.
[2]	This input represents the counterparty default rate derived from the MHFG Group’s own internal credit analyses.
[3]	These inputs are mainly used for determining the fair values of securitization products such as CDO, CLO and ABS, other than RMBS and CMBS.
[4]	This input is mainly used for determining the fair values of Japanese corporate bonds and foreign corporate bonds.
[5]	Weighted averages are calculated by weighting each input by the relative fair value of the respective financial instruments.

Fair Value (Summary of Assets_3

Fair Value (Summary of Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis) (Detail) - JPY (¥) ¥ in Millions	Sep. 30, 2019	Mar. 31, 2019
Assets:
Equity securities	¥ 227,142	¥ 212,270
Fair Value, Measurements, Nonrecurring
Assets:
Loans	128,000	125,000
Loans held-for-sale	62,000	3,000
Equity securities	8,000	1,000
Other investments	3,000	98,000
Premises and equipment-net	1,000	9,000
Total assets measured at fair value	202,000	236,000
Fair Value, Measurements, Nonrecurring | Aggregate cost
Assets:
Loans	171,000	177,000
Loans held-for-sale	64,000	3,000
Equity securities	2,000	1,000
Other investments	5,000	104,000
Premises and equipment-net	5,000	34,000
Intangible assets		1,000
Total assets measured at fair value	247,000	320,000
Fair Value, Measurements, Nonrecurring | Level 1
Assets:
Other investments	3,000	98,000
Total assets measured at fair value	3,000	98,000
Fair Value, Measurements, Nonrecurring | Level 2
Assets:
Loans	8,000	41,000
Loans held-for-sale	62,000	3,000
Premises and equipment-net	1,000	4,000
Total assets measured at fair value	71,000	48,000
Fair Value, Measurements, Nonrecurring | Level 3
Assets:
Loans	120,000	84,000
Equity securities	8,000	1,000
Premises and equipment-net		5,000
Total assets measured at fair value	¥ 128,000	¥ 90,000

Fair Value (Carrying Amounts an

Fair Value (Carrying Amounts and Fair Values of Certain Financial Instruments, Excluding Financial Instruments Carried at Fair Value on a Recurring Basis and Those outside Scope of ASC 825) (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2019	Mar. 31, 2019
Financial liabilities:
Long-term debt		¥ 2,662,041	¥ 2,433,294
Carrying amount
Financial assets:
Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions		61,739,000	62,012,000
Investments		1,064,000	1,604,000
Loans, net of allowance for loan losses	[1]	83,443,000	82,382,000
Financial liabilities:
Noninterest-bearing deposits, call money and funds purchased, and payables under repurchase agreements and securities lending transactions		48,827,000	44,918,000
Interest-bearing deposits		112,303,000	112,658,000
Due to trust accounts		320,000	312,000
Other short-term borrowings		1,608,000	1,995,000
Long-term debt		7,774,000	9,096,000
Estimated fair value
Financial assets:
Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions		61,739,000	62,012,000
Investments		1,075,000	1,609,000
Loans, net of allowance for loan losses	[1]	84,611,000	83,490,000
Financial liabilities:
Noninterest-bearing deposits, call money and funds purchased, and payables under repurchase agreements and securities lending transactions		48,827,000	44,918,000
Interest-bearing deposits		112,312,000	112,655,000
Due to trust accounts		320,000	312,000
Other short-term borrowings		1,608,000	1,995,000
Long-term debt		7,923,000	9,178,000
Estimated fair value | Level 1
Financial assets:
Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions		1,011,000	873,000
Investments		660,000	1,140,000
Financial liabilities:
Noninterest-bearing deposits, call money and funds purchased, and payables under repurchase agreements and securities lending transactions		26,954,000	24,983,000
Interest-bearing deposits		55,404,000	55,542,000
Estimated fair value | Level 2
Financial assets:
Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions		60,728,000	61,139,000
Investments		415,000	469,000
Financial liabilities:
Noninterest-bearing deposits, call money and funds purchased, and payables under repurchase agreements and securities lending transactions		21,873,000	19,935,000
Interest-bearing deposits		56,908,000	57,113,000
Due to trust accounts		320,000	312,000
Other short-term borrowings		1,608,000	1,995,000
Long-term debt		7,071,000	8,336,000
Estimated fair value | Level 3
Financial assets:
Loans, net of allowance for loan losses	[1]	84,611,000	83,490,000
Financial liabilities:
Long-term debt		¥ 852,000	¥ 842,000
[1]	Loans, net of allowance for loan losses include items measured at fair value on a nonrecurring basis.

Offsetting of Financial Asset_3

Offsetting of Financial Assets and Financial Liabilities (Information of Offsetting of Financial Assets and Financial Liabilities) (Detail) - JPY (¥) ¥ in Billions		Sep. 30, 2019	Mar. 31, 2019
Offsetting Financial Assets And Financial Liabilities [Line Items]
Derivative assets, Gross amounts recognized	[1]	¥ 9,026	¥ 7,403
Derivative assets, Gross amounts offset on the balance sheet	[1]	0	0
Derivative assets, Net amounts presented on the balance sheet	[1],[2]	9,026	7,403
Derivative assets, Amounts not offset on the balance sheet, Financial instruments	[1],[3],[4]	(7,372)	(5,903)
Derivative assets, Amounts not offset on the balance sheet, Cash collateral	[1],[3]	(466)	(528)
Derivative assets, Net amounts	[1]	1,188	972
Receivables under resale agreements, Gross amounts recognized	[1]	13,401	12,589
Receivables under resale agreements, Gross amounts offset on the balance sheet	[1]	0	0
Receivables under resale agreements, Net amounts presented on the balance sheet	[1],[2]	13,401	12,589
Receivables under resale agreements, Amounts not offset on the balance sheet, Financial instruments	[1],[3],[4]	(13,386)	(12,579)
Receivables under resale agreements, Amounts not offset on the balance sheet, Cash collateral	[1],[3]	0	0
Receivables under resale agreements, Net amounts	[1]	15	10
Receivables under securities borrowing transactions, Gross amounts recognized	[1]	2,316	1,921
Receivables under securities borrowing transactions, Gross amounts offset on the balance sheet	[1]	0	0
Receivables under securities borrowing transactions, Net amounts presented on the balance sheet	[1],[2]	2,316	1,921
Receivables under securities borrowing transactions, Amounts not offset on the balance sheet, Financial instruments	[1],[3],[4]	(2,265)	(1,894)
Receivables under securities borrowing transactions, Amounts not offset on the balance sheet, Cash collateral	[1],[3]	0	0
Receivables under securities borrowing transactions, Net amounts	[1]	51	27
Financial assets, Gross amounts recognized, Total	[1]	24,743	21,913
Financial assets, Gross amounts offset on the balance sheet, Total	[1]	0	0
Financial assets, Net amounts presented on the balance sheet, Total	[1],[2]	24,743	21,913
Financial assets, Amounts not offset on the balance sheet, Financial instruments, Total	[1],[3],[4]	(23,023)	(20,376)
Financial assets, Amounts not offset on the balance sheet, Cash collateral, Total	[1],[3]	(466)	(528)
Financial assets, Net amounts, Total	[1]	1,254	1,009
Derivative liabilities, Gross amounts recognized	[1]	8,545	6,978
Derivative liabilities, Gross amounts offset on the balance sheet	[1]	0	0
Derivative liabilities, Net amounts presented on the balance sheet	[1],[2]	8,545	6,978
Derivative liabilities, Amounts not offset on the balance sheet, Financial instruments	[1],[3],[4]	(7,225)	(5,766)
Derivative liabilities, Amounts not offset on the balance sheet, Cash collateral	[1],[3]	(893)	(769)
Derivative liabilities, Net amounts	[1]	427	443
Payables under repurchase agreements, Gross amounts recognized	[1]	16,837	14,312
Payables under repurchase agreements, Gross amounts offset on the balance sheet	[1]	0	0
Payables under repurchase agreements, Net amounts presented on the balance sheet	[1],[2]	16,837	14,312
Payables under repurchase agreements, Amounts not offset on the balance sheet, Financial instruments	[1],[3],[4]	(16,798)	(14,309)
Payables under repurchase agreements, Amounts not offset on the balance sheet, Cash collateral	[1],[3]	0	0
Payables under repurchase agreements, Net amounts	[1]	39	3
Payables under securities lending transactions, Gross amounts recognized	[1]	1,024	932
Payables under securities lending transactions, Gross amounts offset on the balance sheet	[1]	0	0
Payables under securities lending transactions, Net amounts presented on the balance sheet	[1],[2]	1,024	932
Payables under securities lending transactions, Amounts not offset on the balance sheet, Financial instruments	[1],[3],[4]	(1,020)	(931)
Payables under securities lending transactions, Amounts not offset on the balance sheet, Cash collateral	[1],[3]	0	0
Payables under securities lending transactions, Net amounts	[1]	4	1
Financial liabilities, Gross amounts recognized, Total	[1]	26,406	22,222
Financial liabilities, Gross amounts offset on the balance sheet, Total	[1]	0	0
Financial liabilities, Net amounts presented on the balance sheet, Total	[1],[2]	26,406	22,222
Financial liabilities, Amounts not offset on the balance sheet, Financial instruments, Total	[1],[3],[4]	(25,043)	(21,006)
Financial liabilities, Amounts not offset on the balance sheet, Cash collateral, Total	[1],[3]	(893)	(769)
Financial liabilities, Net amounts, Total	[1]	¥ 470	¥ 447
[1]	Amounts relating to master netting arrangements or similar agreements where the MHFG Group does not have the legal right of set-off or where uncertainty exists as to the enforceability of these agreements are excluded. For derivatives, the table includes amounts relating to over-the-counter (“OTC”) and OTC-cleared derivatives that are subject to enforceable master netting arrangements or similar agreements.
[2]	Derivative assets and liabilities are recorded in Trading account assets and Trading account liabilities, respectively.
[3]	Amounts do not exceed the net amounts presented on the balance sheet and do not include the effect of overcollateralization, where it exists.
[4]	For derivatives, amounts include derivative assets or liabilities and securities collateral that are eligible for offsetting under enforceable master netting arrangements or similar agreements.

Repurchase Agreements and Sec_3

Repurchase Agreements and Securities Lending Transactions Accounted for as Secured Borrowings (Gross Amounts of Liabilities by Remaining Contractual Maturity) (Detail) - JPY (¥) ¥ in Billions		Sep. 30, 2019	Mar. 31, 2019
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	[1]	¥ 17,340	¥ 14,640
Securities lending transactions	[1]	1,857	1,798
Total		19,197	16,438
Overnight and continuous
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		6,727	2,596
Securities lending transactions		807	1,012
Total		7,534	3,608
Up to 30 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		6,976	8,537
Securities lending transactions		660	473
Total		7,636	9,010
31 to 90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		1,858	2,403
Securities lending transactions		110
Total		1,968	2,403
Greater than 90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		1,779	1,104
Securities lending transactions		280	313
Total		¥ 2,059	¥ 1,417
[1]	Amounts exceeded the gross amounts recognized in Note 18 “Offsetting of financial assets and financial liabilities” by ¥1,194 billion and ¥1,336 billion, at March 31, 2019 and September 30, 2019, respectively, which excluded the amounts relating to master netting agreements or similar agreements where the MHFG Group did not have the legal right of set-off or where uncertainty exists as to the enforceability.

Repurchase Agreements and Sec_4

Repurchase Agreements and Securities Lending Transactions Accounted for as Secured Borrowings (Gross Amounts of Liabilities by Class of Underlying Collateral) (Detail) - JPY (¥) ¥ in Billions		Sep. 30, 2019	Mar. 31, 2019
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	[1]	¥ 17,340	¥ 14,640
Securities lending transactions	[1]	1,857	1,798
Japanese government bonds and Japanese local government bonds
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		3,097	2,118
Securities lending transactions		471	430
Foreign government bonds and foreign agency mortgage-backed securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		13,272	11,613
Securities lending transactions		597	396
Commercial Paper and Corporate Bonds
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		268	223
Securities lending transactions		52	52
Equity Securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		495	492
Securities lending transactions		720	902
Other securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements		208	194
Securities lending transactions		¥ 17	¥ 18
[1]	Amounts exceeded the gross amounts recognized in Note 18 “Offsetting of financial assets and financial liabilities” by ¥1,194 billion and ¥1,336 billion, at March 31, 2019 and September 30, 2019, respectively, which excluded the amounts relating to master netting agreements or similar agreements where the MHFG Group did not have the legal right of set-off or where uncertainty exists as to the enforceability.

Repurchase Agreements and Sec_5

Repurchase Agreements and Securities Lending Transactions Accounted for as Secured Borrowings (Gross Amounts of Liabilities by Class of Underlying Collateral) (Parenthetical) (Detail) - JPY (¥) ¥ in Billions	Sep. 30, 2019	Mar. 31, 2019
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Amounts exceeded the gross amounts recognized in offsetting of financial assets and financial liabilities	¥ 1,336	¥ 1,194

Business Segment Information -

Business Segment Information - Additional Information (Detail)	6 Months Ended
	Sep. 30, 2019Segment
Segment Reporting Information [Line Items]
Number of operating segments	5

Business Segment Information (R

Business Segment Information (Reportable Segment Information Derived from Internal Management Reporting Systems, on Basis of Japanese GAAP) (Detail) - JPY (¥) ¥ in Billions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	¥ 1,022.8	¥ 1,051.5
General and administrative expenses	[1],[3]	688.4	722.7
Equity in earnings (losses) of equity method investees-net	[1]	19.1	19.4
Amortization of goodwill and others	[1]	6.7	6.8
Others	[1]	(5.9)	(10.4)
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4]	340.9	331
Fixed assets	[5]	1,701.6
Operating Segments | Retail And Business Banking Company
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	322.3	345
General and administrative expenses	[1],[3]	328	360
Equity in earnings (losses) of equity method investees-net	[1]	6.7	14.4
Amortization of goodwill and others	[1]	0.2	0.2
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4]	0.8	(0.8)
Fixed assets	[5]	491.2
Operating Segments | Corporate And Institutional Company
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	221.9	223.1
General and administrative expenses	[1],[3]	104.3	103.5
Equity in earnings (losses) of equity method investees-net	[1]	1.1	0.6
Amortization of goodwill and others	[1]	0.2	0.2
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4]	118.5	120
Fixed assets	[5]	214.9
Operating Segments | Global Corporate Company
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	208	190.3
General and administrative expenses	[1],[3]	120.7	115.6
Equity in earnings (losses) of equity method investees-net	[1]	6	2.8
Amortization of goodwill and others	[1]	0.2	0.2
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4]	93.1	77.3
Fixed assets	[5]	173.3
Operating Segments | Global Markets Company
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	231.5	237.7
General and administrative expenses	[1],[3]	103.4	105.6
Amortization of goodwill and others	[1]	1.2	1.2
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4]	126.9	130.9
Fixed assets	[5]	91.9
Operating Segments | Asset Management Company
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	23.2	25
General and administrative expenses	[1],[3]	14.4	13.9
Equity in earnings (losses) of equity method investees-net	[1]	0.6	0.6
Amortization of goodwill and others	[1]	3.9	4
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4]	5.5	7.7
Fixed assets	[5]	0.1
Others
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2],[6]	15.9	30.4
General and administrative expenses	[1],[3],[6]	17.6	24.1
Equity in earnings (losses) of equity method investees-net	[1],[6]	4.7	1
Amortization of goodwill and others	[1],[6]	1	1
Others	[1],[6]	(5.9)	(10.4)
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4],[6]	(3.9)	¥ (4.1)
Fixed assets	[5],[6]	¥ 730.2
[1]	The MHFG Group adopted certain enhancements, which were not significant individually or in the aggregate, to the Group’s segment allocation methods under internal managerial accounting rules and practices, and accordingly, the figures for the six months ended September 30, 2018 have been restated to reflect these current period enhancements. Furthermore, income and expenses of foreign branches of MHBK and foreign subsidiaries with functional currencies other than Japanese Yen have been translated for purposes of segment reporting using the budgeted foreign currency rates. Prior period comparative amounts for such foreign currency income and expenses have been translated using current period budgeted foreign currency rates.
[2]	“Gross profits + Net gains (losses) related to ETFs and others” is reported instead of sales reported by general corporations. Gross profits is defined as the sum of net interest income, fiduciary income, net fee and commission income, net trading income and net other operating income. Net gains (losses) related to ETFs and others consist of net gains (losses) on ETFs held by MHBK and MHTB on their non-consolidated basis and net gains (losses) on operating investment securities of MHSC on its consolidated basis. For the six months ended September 30, 2018 and 2019, net gains (losses) related to ETFs and others amounted to ¥39.9 billion and ¥(8.0) billion, respectively, of which ¥33.7 billion and ¥(11.2) billion are included in “Global Markets Company”, respectively.
[3]	“General and administrative expenses” excludes non-recurring losses.
[4]	Net business profits (losses) is used in Japan as a measure of the profitability of core banking operations and is defined as gross profits (as defined above) less general and administrative expenses plus equity in earnings (losses) of equity method investees—net and others. Measurement of net business profits (losses) is required for regulatory reporting to the Financial Services Agency of Japan.
[5]	“Fixed assets” is presented based on Japanese GAAP and corresponds to the total amount of the following U.S. GAAP accounts: Premises and equipment—net, Goodwill, Intangible assets, and ROU assets related to operating leases included in Other assets. The above table does not include other asset amounts because “Fixed assets” is the only balance sheet metric that management uses when evaluating and making decisions pertaining to the operating segments. “Fixed assets” has been allocated to each segment starting in the fiscal year ended March 31, 2019 to enhance management’s analysis of the Group’s operations. “Others” in “Fixed assets” includes assets of headquarters that have not been allocated to each segment, “Fixed assets” pertaining to consolidated subsidiaries that are not subject to allocation, consolidating adjustments, and others. Certain “Fixed assets” expenses have been allocated to each segment using reasonable allocation criteria.
[6]	“Others” includes the following items: • profits and expenses pertaining to consolidated subsidiaries that are not subject to allocation; • consolidating adjustments, including eliminating internal transaction between each segment; • Equity in earnings (losses) of equity method investees-net that are not subject to allocation; and • profits and losses pertaining to derivative transactions that reflect the counterparty risk of the individual parties and other factors in determining fair market value.

Business Segment Information _2

Business Segment Information (Reportable Segment Information Derived from Internal Management Reporting Systems, on Basis of Japanese GAAP) (Parenthetical) (Detail) - JPY (¥) ¥ in Billions		6 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits and net gains (losses) related to ETFs and others	[1],[2]	¥ 1,022.8	¥ 1,051.5
Exchange Traded Funds
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits and net gains (losses) related to ETFs and others		(8)	39.9
Global Markets Company | Exchange Traded Funds
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits and net gains (losses) related to ETFs and others		¥ (11.2)	¥ 33.7
[1]	The MHFG Group adopted certain enhancements, which were not significant individually or in the aggregate, to the Group’s segment allocation methods under internal managerial accounting rules and practices, and accordingly, the figures for the six months ended September 30, 2018 have been restated to reflect these current period enhancements. Furthermore, income and expenses of foreign branches of MHBK and foreign subsidiaries with functional currencies other than Japanese Yen have been translated for purposes of segment reporting using the budgeted foreign currency rates. Prior period comparative amounts for such foreign currency income and expenses have been translated using current period budgeted foreign currency rates.
[2]	“Gross profits + Net gains (losses) related to ETFs and others” is reported instead of sales reported by general corporations. Gross profits is defined as the sum of net interest income, fiduciary income, net fee and commission income, net trading income and net other operating income. Net gains (losses) related to ETFs and others consist of net gains (losses) on ETFs held by MHBK and MHTB on their non-consolidated basis and net gains (losses) on operating investment securities of MHSC on its consolidated basis. For the six months ended September 30, 2018 and 2019, net gains (losses) related to ETFs and others amounted to ¥39.9 billion and ¥(8.0) billion, respectively, of which ¥33.7 billion and ¥(11.2) billion are included in “Global Markets Company”, respectively.

Business Segment Information _3

Business Segment Information (Reconciliation of Total Net Business Profits under Internal Management Reporting Systems to Income Before Income Tax Expense on Consolidated Statements of Income) (Detail) - JPY (¥) ¥ in Millions	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net business profits (losses) + Net gains (losses) related to ETFs and others	¥ 340,900	¥ 331,000
Adjustment to reconcile management reporting to Japanese GAAP:
General and administrative expenses (non-recurring losses)	24,500	12,000
Expenses related to portfolio problems (including reversal of (provision for) general reserve for losses on loans)	(19,100)	(20,800)
Gains on reversal of reserves for possible losses on loans, and others	7,900	50,600
Net gains (losses) related to stocks—Net gains (losses) related to ETFs and others	55,400	110,100
Net extraordinary gains(losses)	(5,000)	6,700
Others	(13,100)	(16,000)
Income before income tax expense under Japanese GAAP	391,500	473,600
Adjustment to reconcile Japanese GAAP to U.S. GAAP:
Derivative financial instruments and hedging activities	105,000	(75,400)
Investments	(163,900)	92,100
Loans	0	(4,200)
Allowances for loan losses and off-balance-sheet instruments	500	(10,500)
Premises and equipment	(51,500)	(77,300)
Land revaluation	500	1,500
Business combinations	4,100	7,500
Pension liabilities	(27,300)	(19,800)
Consolidation of variable interest entities	40,300	43,900
Foreign currency translation	14,300	(8,500)
Others	(3,000)	(5,300)
Income before income tax expense under U.S. GAAP	¥ 310,456	¥ 417,650

Business Segment Information _4

Business Segment Information (Reconciliation of Assets from Segment to Consolidated) (Detail) ¥ in Billions	6 Months Ended
	Sep. 30, 2019JPY (¥)
Schedule Of Assets By Segment [Line Items]
Fixed assets	¥ 1,701.6	[1]
U.S. GAAP adjustments	964.5
Premises and equipment—net, Goodwill, Intangible assets, and ROU assets related to operating leases included in Other assets	¥ 2,666.1
[1]	“Fixed assets” is presented based on Japanese GAAP and corresponds to the total amount of the following U.S. GAAP accounts: Premises and equipment—net, Goodwill, Intangible assets, and ROU assets related to operating leases included in Other assets. The above table does not include other asset amounts because “Fixed assets” is the only balance sheet metric that management uses when evaluating and making decisions pertaining to the operating segments. “Fixed assets” has been allocated to each segment starting in the fiscal year ended March 31, 2019 to enhance management’s analysis of the Group’s operations. “Others” in “Fixed assets” includes assets of headquarters that have not been allocated to each segment, “Fixed assets” pertaining to consolidated subsidiaries that are not subject to allocation, consolidating adjustments, and others. Certain “Fixed assets” expenses have been allocated to each segment using reasonable allocation criteria.