Aflac (AFL) 10-K 25 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 16, 2016	Jun. 30, 2015
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Trading Symbol	AFL
Entity Registrant Name	AFLAC INC
Entity Central Index Key	4,977
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		420,001,378
Entity Public Float			$ 26,502,846,889

Consolidated Statements of Earn

Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Revenues:
Net premiums, principally supplemental health insurance		$ 17,570		$ 19,072	$ 20,135
Net investment income		3,135		3,319	3,293
Realized investment gains (losses):
Other-than-temporary impairment losses realized	[1]	(153)		(31)	(199)
Sales and redemptions		303		215	262
Derivative and other gains (losses)		(10)		31	336
Total realized investment gains (losses)		140		215	399
Other income (loss)		27		122	112
Total revenues		20,872		22,728	23,939
Benefits and expenses:
Benefits and claims, net		11,746		12,937	13,813
Acquisition and operating expenses:
Amortization of deferred policy acquisition costs		1,066		1,108	1,074
Insurance commissions		1,303		1,436	1,528
Insurance expenses		2,214		2,261	2,222
Interest expense		289		317	293
Other operating expenses		392	[2]	178	193
Total acquisition and operating expenses		5,264		5,300	5,310
Total benefits and expenses		17,010		18,237	19,123
Earnings before income taxes		3,862		4,491	4,816
Income Tax Expense:
Current		1,288		1,079	1,236
Deferred		41		461	422
Total income tax expense		1,329		1,540	1,658
Net earnings		$ 2,533		$ 2,951	$ 3,158
Net earnings per share:
Basic (in dollars per share)		$ 5.88		$ 6.54	$ 6.80
Diluted (in dollars per share)		$ 5.85		$ 6.50	$ 6.76
Weighted-average outstanding common shares used in computing earnings per share (In thousands):
Basic (in shares)		430,654		451,204	464,502
Diluted (in shares)		433,172		454,000	467,408
8.50% senior notes due May 2019
Expense on extinguishment of debt, make-whole premium		$ 230
[1]	Includes $131 and $45 for the years ended December 31, 2015 and 2013, respectively, for credit-related impairments; $26 for the year ended December 31, 2013 for impairments due to severity and duration of decline in fair value; and $22, $31 and $128 for the years ended December 31, 2015, 2014 and 2013, respectively, from change in intent to sell securities
[2]	Includes expense of $230 for the make-whole payment associated with the early extinguishment of debt

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net earnings		$ 2,533	$ 2,951	$ 3,158
Other comprehensive income (loss) before income taxes:
Unrealized foreign currency translation gains (losses) during period		360	(1,455)	(1,588)
Unrealized gains (losses) on investment securities:
Unrealized holding gains (losses) on investment securities during period		(2,534)	5,947	(2,362)
Reclassification adjustment for realized (gains) losses on investment securities included in net earnings		(61)	(54)	(56)
Unrealized gains (losses) on derivatives during period		0	(17)	(10)
Pension liability adjustment during period		(20)	(76)	157
Total other comprehensive income (loss) before income taxes		(2,255)	4,345	(3,859)
Income tax expense (benefit) related to items of other comprehensive income (loss)		(901)	1,803	(581)
Other comprehensive income (loss), net of income taxes	[1]	(1,354)	2,542	(3,278)
Total comprehensive income (loss)		$ 1,179	$ 5,493	$ (120)
[1]	All amounts in the table above are net of tax.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Securities held to maturity, at amortized cost:
Fixed maturities		$ 33,459	$ 34,242
Other investments		294	171
Cash and cash equivalents		4,350	4,658
Total investments and cash		105,897	107,341
Receivables		705	842
Accrued investment income		768	762
Deferred policy acquisition costs		8,511	8,273
Property and equipment, at cost less accumulated depreciation		427	429
Other	[1]	1,988	2,120
Total assets		118,296	119,767
Policy liabilities:
Future policy benefits		69,687	65,646
Unpaid policy claims		3,802	3,630
Unearned premiums		7,857	8,626
Other policyholders' funds		6,285	6,031
Total policy liabilities		87,631	83,933
Income taxes		4,340	5,293
Payables for return of cash collateral on loaned securities		941	2,193
Notes payable		5,011	5,282
Other	[2]	$ 2,665	$ 4,719
Commitments and contingent liabilities (Note 14)
Total liabilities		$ 100,588	$ 101,420
Shareholders' equity:
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2015 and 2014; issued 669,723 shares in 2015 and 668,132 shares in 2014		67	67
Additional paid-in capital		1,828	1,711
Retained earnings		24,007	22,156
Accumulated other comprehensive income (loss):
Unrealized foreign currency translation gains (losses)		(2,196)	(2,541)
Unrealized gains (losses) on investment securities		2,986	4,672
Unrealized gains (losses) on derivatives		(26)	(26)
Pension liability adjustment		(139)	(126)
Treasury stock, at average cost		(8,819)	(7,566)
Total shareholders' equity		17,708	18,347
Total liabilities and shareholders' equity		118,296	119,767
Investments Other Than Consolidated Variable Interest Entities
Securities available for sale, at fair value:
Fixed maturities		60,795	61,407
Perpetual securities		1,719	2,240
Equity securities		135	28
Securities held to maturity, at amortized cost:
Fixed maturities		33,459	34,159
Variable Interest Entity, Consolidated
Securities available for sale, at fair value:
Fixed maturities		4,554	4,166
Perpetual securities		228	429
Equity securities		363	0
Securities held to maturity, at amortized cost:
Fixed maturities		$ 0	$ 83
[1]	Includes $102 in 2015 and $106 in 2014 of derivatives from consolidated variable interest entities
[2]	Includes $293 in 2015 and $318 in 2014 of derivatives from consolidated variable interest entities

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Securities held to maturity, fixed maturities, fair value	$ 37,520	$ 38,497
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	1,900,000	1,900,000
Common stock, shares issued (in shares)	669,723	668,132
Asset derivatives	$ 676	$ 802
Liability derivatives	371	2,423
Investments Other Than Consolidated Variable Interest Entities
Securities available for sale, fixed maturities, amortized cost	56,903	55,365
Securities available for sale, perpetual securities, amortized cost	1,586	2,035
Securities available for sale, equity securities, cost	117	19
Securities held to maturity, fixed maturities, fair value	37,520	38,413
Variable Interest Entity, Consolidated
Securities available for sale, fixed maturities, amortized cost	3,739	3,020
Securities available for sale, perpetual securities, amortized cost	255	405
Securities available for sale, equity securities, cost	363	0
Securities held to maturity, fixed maturities, fair value	0	84
Asset derivatives	102	106
Liability derivatives	$ 293	$ 318

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) $ in Millions	Total	Common stock:	Additional paid-in capital:	Retained earnings:	Accumulated other comprehensive income (loss):	Treasury stock:
Balance, beginning of period at Dec. 31, 2012		$ 67	$ 1,505	$ 17,387	$ 2,715	$ (5,696)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options			50
Share-based compensation			32
Net earnings	$ 3,158			3,158
Dividends to shareholders ($1.58 per share in 2015, $1.50 per share in 2014 and $1.42 per share in 2013)				(660)
Unrealized foreign currency translation gains (losses) during period, net of income taxes					(1,838)
Unrealized gains (losses) on investment securities during the period, net of income taxes and reclassification adjustments					(1,535)
Unrealized gains (losses) on derivatives during period, net of income taxes					(7)
Pension liability adjustment during period, net of income taxes					102
Purchases of treasury stock						(813)
Treasury stock reissued			57			96
Balance, end of period at Dec. 31, 2013	14,620	67	1,644	19,885	(563)	(6,413)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options			29
Share-based compensation			(3)
Net earnings	2,951			2,951
Dividends to shareholders ($1.58 per share in 2015, $1.50 per share in 2014 and $1.42 per share in 2013)				(680)
Unrealized foreign currency translation gains (losses) during period, net of income taxes					(1,036)
Unrealized gains (losses) on investment securities during the period, net of income taxes and reclassification adjustments					3,637
Unrealized gains (losses) on derivatives during period, net of income taxes					(14)
Pension liability adjustment during period, net of income taxes					(45)
Purchases of treasury stock						(1,210)
Treasury stock reissued			41			57
Balance, end of period at Dec. 31, 2014	18,347	67	1,711	22,156	1,979	(7,566)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options			43
Share-based compensation			36
Net earnings	2,533			2,533
Dividends to shareholders ($1.58 per share in 2015, $1.50 per share in 2014 and $1.42 per share in 2013)				(682)
Unrealized foreign currency translation gains (losses) during period, net of income taxes					345
Unrealized gains (losses) on investment securities during the period, net of income taxes and reclassification adjustments					(1,686)
Unrealized gains (losses) on derivatives during period, net of income taxes					0
Pension liability adjustment during period, net of income taxes					(13)
Purchases of treasury stock						(1,315)
Treasury stock reissued			38			62
Balance, end of period at Dec. 31, 2015	$ 17,708	$ 67	$ 1,828	$ 24,007	$ 625	$ (8,819)

Consolidated Statements of Sha7

Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Retained earnings:
Dividends to shareholders (in dollars per share)	$ 1.58	$ 1.50	$ 1.42

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net earnings		$ 2,533		$ 2,951	$ 3,158
Adjustments to reconcile net earnings to net cash provided by operating activities:
Change in receivables and advance premiums		147		(7)	(8)
Increase in deferred policy acquisition costs		(241)		(225)	(404)
Increase in policy liabilities		3,524		3,614	6,806
Change in income tax liabilities		(36)		123	993
Realized investment (gains) losses		(140)		(215)	(399)
Other Noncash Income (Expense)		(989)	[1]	(309)	(401)
Net cash provided (used) by operating activities		6,776		6,550	10,547
Securities available for sale:
Fixed maturities sold		3,224		4,178	9,631
Fixed maturities matured or called		1,132		1,001	2,907
Perpetual securities sold		0		0	264
Perpetual securities matured or called		647		203	256
Equity securities sold		1		0	0
Securities held to maturity:
Fixed maturities matured or called		766		8,475	6,515
Costs of investments acquired:
Available for sale fixed maturities acquired		(6,507)		(10,978)	(22,967)
Available-for-sale equity securities acquired		(454)		(5)	0
Held to maturity fixed maturities acquired		0		(3,564)	(6,756)
Other investments, net		(70)		272	(319)
Purchase of subsidiary		(40)		0	0
Settlement of derivatives, net		(2,119)		(636)	(1,624)
Cash received (pledged or returned) as collateral, net		(1,391)		(3,217)	1,037
Other, net		(86)		30	(35)
Net cash provided (used) by investing activities		(4,897)		(4,241)	(11,091)
Cash flows from financing activities:
Purchases of treasury stock		(1,315)		(1,210)	(813)
Proceeds from borrowings		998		750	700
Principal payments under debt obligations		(1,272)		(335)	0
Dividends paid to shareholders		(656)		(654)	(635)
Change in investment-type contracts, net		256		1,253	1,790
Treasury stock reissued		36		33	88
Other, net		(234)	[1]	16	6
Net cash provided (used) by financing activities		(2,187)		(147)	1,136
Effect of exchange rate changes on cash and cash equivalents		0		(47)	(90)
Net change in cash and cash equivalents		(308)		2,115	502
Cash and cash equivalents, beginning of period		4,658		2,543	2,041
Cash and cash equivalents, end of period		4,350		4,658	2,543
Supplemental disclosures of cash flow information:
Income taxes paid		996		1,416	754
Interest paid		236		241	210
Noncash interest		53		76	82
Impairment losses included in realized investment losses	[2]	153		31	199
Noncash financing activities:
Capitalized lease obligations		6		9	0
Associate stock bonus
Noncash financing activities:
Treasury stock issued		35		35	36
Shareholder dividend reinvestment
Noncash financing activities:
Treasury stock issued		26		26	25
Share-based compensation grants
Noncash financing activities:
Treasury stock issued		3		$ 4	$ 4
8.50% senior notes due May 2019
Expense on extinguishment of debt, make-whole premium		$ 230
[1]	Operating activities excludes and financing activities includes a cash outflow of $230 for the make-whole payment associated with the early extinguishment of debt
[2]	Includes $131 and $45 for the years ended December 31, 2015 and 2013, respectively, for credit-related impairments; $26 for the year ended December 31, 2013 for impairments due to severity and duration of decline in fair value; and $22, $31 and $128 for the years ended December 31, 2015, 2014 and 2013, respectively, from change in intent to sell securities

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Description of Business   Aflac Incorporated (the Parent Company) and its subsidiaries (collectively, the Company) primarily sell supplemental health and life insurance in the United States and Japan. The Company's insurance business is marketed and administered through American Family Life Assurance Company of Columbus (Aflac), which operates in the United States (Aflac U.S.) and as a branch in Japan (Aflac Japan). American Family Life Assurance Company of New York (Aflac New York) is a wholly owned subsidiary of Aflac. Most of Aflac's policies are individually underwritten and marketed through independent agents. Additionally, Aflac U.S. markets and administers group products through Continental American Insurance Company (CAIC), branded as Aflac Group Insurance. Our insurance operations in the United States and our branch in Japan service the two markets for our insurance business. Aflac Japan's revenues, including realized gains and losses on its investment portfolio, accounted for 70% of the Company's total revenues in 2015 , compared with 72% in 2014 and 74% in 2013 . The percentage of the Company's total assets attributable to Aflac Japan was 83% at December 31, 2015 , compared with 82% at December 31, 2014 . Basis of Presentation We prepare our financial statements in accordance with U.S. generally accepted accounting principles (GAAP). These principles are established primarily by the Financial Accounting Standards Board (FASB). In these Notes to the Consolidated Financial Statements, references to U.S. GAAP issued by the FASB are derived from the FASB Accounting Standards Codification TM (ASC). The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates when recording transactions resulting from business operations based on currently available information. The most significant items on our balance sheet that involve a greater degree of accounting estimates and actuarial determinations subject to changes in the future are the valuation of investments, deferred policy acquisition costs, liabilities for future policy benefits and unpaid policy claims, and income taxes. These accounting estimates and actuarial determinations are sensitive to market conditions, investment yields, mortality, morbidity, commission and other acquisition expenses, and terminations by policyholders. As additional information becomes available, or actual amounts are determinable, the recorded estimates will be revised and reflected in operating results. Although some variability is inherent in these estimates, we believe the amounts provided are adequate. The consolidated financial statements include the accounts of the Parent Company, its subsidiaries and those entities required to be consolidated under applicable accounting standards. All material intercompany accounts and transactions have been eliminated. Significant Accounting Policies Translation of Foreign Currencies:  The functional currency of Aflac Japan's insurance operations is the Japanese yen. We translate our yen-denominated financial statement accounts into U.S. dollars as follows. Assets and liabilities are translated at end-of-period exchange rates. Realized gains and losses on security transactions are translated at the exchange rate on the trade date of each transaction. Other revenues, expenses and cash flows are translated using average exchange rates for the period. The resulting currency translation adjustments are reported in accumulated other comprehensive income. We include in earnings the realized currency exchange gains and losses resulting from foreign currency transactions. Prior to October 1, 2013, Aflac Japan maintained an investment portfolio of U.S. dollar-denominated securities on behalf of Aflac U.S., which served as an economic currency hedge of a portion of our investment in Aflac Japan. The functional currency for these investments was the U.S. dollar. The related investment income and realized/unrealized investment gains and losses were denominated in U.S. dollars. Since the functional currency of this portfolio was the U.S. dollar, there was no translation adjustment to record in other comprehensive income for these investments when the yen/dollar exchange rate changed. The foreign exchange gains and losses related to this portfolio continue to be taxable in Japan and the U.S. when the securities matured or were sold. Until maturity or sale, deferred tax expense or benefit associated with the foreign exchange gains or losses is recognized in income tax expense on other comprehensive income. As of October 1, 2013, these investments were transferred into the Aflac Japan investment portfolio. These investments began to have remeasurement and translation effects recorded in other comprehensive income in the fourth quarter of 2013. We have designated a majority of the Parent Company's yen-denominated liabilities (Samurai and Uridashi notes and yen-denominated loans) as non-derivative hedges and designated foreign currency forwards and options as derivative hedges of the foreign currency exposure of our investment in Aflac Japan. Outstanding principal and related accrued interest on these Parent Company liabilities and the fair value of these derivatives are translated into U.S. dollars at end-of-period exchange rates. Currency translation adjustments and changes in the fair value of these derivatives are recorded as unrealized foreign currency translation gains (losses) in other comprehensive income and are included in accumulated other comprehensive income. Insurance Revenue and Expense Recognition:  The supplemental health and life insurance policies we issue are classified as long-duration contracts. The contract provisions generally cannot be changed or canceled during the contract period; however, we may adjust premiums for supplemental health policies issued in the United States within prescribed guidelines and with the approval of state insurance regulatory authorities. Insurance premiums for most of the Company's health and life policies are recognized ratably as earned income over the premium payment periods of the policies. When revenues are reported, the related amounts of benefits and expenses are charged against such revenues, so that profits are recognized in proportion to premium revenues during the period the policies are expected to remain in force. This association is accomplished by means of annual additions to the liability for future policy benefits and the deferral and subsequent amortization of policy acquisition costs. Premiums from the Company's products with limited-pay features are collected over a significantly shorter period than the period over which benefits are provided. Premiums for these products are recognized ratably over the scheduled premium payment period. At the policyholder's option, customers can also pay discounted advanced premiums for certain of these products. Advanced premiums are deferred and recognized ratably over the regularly scheduled premium payment period. For the Company's limited-pay products, any gross premium in excess of the net premium is deferred during the scheduled premium payment period and recognized into benefits in a constant relationship with insurance in force. Benefits are recorded as an expense when they are incurred. A liability for future policy benefits is recorded when premiums are recognized using the net premium method. The calculation of deferred policy acquisition costs (DAC) and the liability for future policy benefits requires the use of estimates based on sound actuarial valuation techniques. For new policy issues, we review our actuarial assumptions and deferrable acquisition costs each year and revise them when necessary to more closely reflect recent experience and studies of actual acquisition costs. For policies in force, we evaluate DAC by major product groupings to determine that they are recoverable from future revenues, and any amounts determined not to be recoverable are charged against net earnings. We have not had any material charges to earnings for DAC that was determined not to be recoverable in any of the years presented in this Form 10-K. Advertising expense is reported as incurred in insurance expenses in the consolidated statements of earnings. Cash and Cash Equivalents:  Cash and cash equivalents include cash on hand, money market instruments and other debt instruments with a maturity of 90 days or less when purchased. Investments:  Our debt securities consist of fixed-maturity securities, which are classified as either held to maturity or available for sale. Securities classified as held to maturity are securities that we have the ability and intent to hold to maturity or redemption and are carried at amortized cost. All other fixed-maturity debt securities, our perpetual securities and our equity securities are classified as available for sale and are carried at fair value. If the fair value is higher than the amortized cost for debt and perpetual securities, or the purchase cost for equity securities, the excess is an unrealized gain, and if lower than cost, the difference is an unrealized loss. The net unrealized gains and losses on securities available for sale, plus the unamortized unrealized gains and losses on debt securities transferred to the held-to-maturity portfolio, less related deferred income taxes, are recorded through other comprehensive income and included in accumulated other comprehensive income. Amortized cost of debt and perpetual securities is based on our purchase price adjusted for accrual of discount, or amortization of premium, and recognition of impairment charges, if any. The amortized cost of debt and perpetual securities we purchase at a discount or premium will equal the face or par value at maturity or the call date, if applicable. Interest is reported as income when earned and is adjusted for amortization of any premium or discount. We have investments in variable interest entities (VIEs). Criteria for evaluating VIEs for consolidation focuses on identifying which enterprise has the power to direct the activities of a variable interest entity that most significantly impact the entity's economic performance and (1) the obligation to absorb losses of the entity or (2) the right to receive benefits from the entity. We are the primary beneficiary of certain VIEs. While the VIEs generally operate within a defined set of documents, there are certain powers that are retained by us that are considered significant in our conclusion that we are the primary beneficiary. These powers vary by structure but generally include the initial selection of the underlying collateral or, for collateralized debt obligations (CDOs), the reference credits to include in the structure; the ability to obtain the underlying collateral in the event of default; and the ability to appoint or dismiss key parties in the structure. In particular, our powers surrounding the underlying collateral were the most significant powers since those most significantly impact the economics of the VIE. We have no obligation to provide any continuing financial support to any of the entities in which we are the primary beneficiary. Our maximum loss is limited to our original investment. Neither we nor any of our creditors have the ability to obtain the underlying collateral, nor do we have control over the instruments in the VIEs, unless there is an event of default. For those entities where we are the primary beneficiary, the assets consolidated are fixed-maturity securities, perpetual securities, equity securities, and derivative instruments; collateral is reported separately under the captions fixed maturities- and perpetual securities- consolidated variable interest entities on our balance sheet. For the mortgage- and asset-backed securities held in our fixed maturities portfolio, we recognize income using a constant effective yield, which is based on anticipated prepayments and the estimated economic life of the securities. When estimates of prepayments change, the effective yield is recalculated to reflect actual payments to date and anticipated future payments. The net investment in mortgage- and asset-backed securities is adjusted to the amount that would have existed had the new effective yield been applied at the time of acquisition. This adjustment is reflected in net investment income. We use the specific identification method to determine the gain or loss from securities transactions and report the realized gain or loss in the consolidated statements of earnings. Securities transactions are accounted for based on values as of the trade date of the transaction. An investment in a fixed maturity, perpetual security or equity security is impaired if the fair value falls below book value. We regularly review our entire investment portfolio for declines in value. Our fixed maturities and investment-grade perpetual securities investments are evaluated for other-than-temporary impairment using our debt impairment model. Our debt impairment model focuses on the ultimate collection of the cash flows from our investments. The determination of the amount of impairments under this model is based upon our periodic evaluation and assessment of known and inherent risks associated with the respective securities. Such evaluations and assessments are revised as conditions change and new information becomes available. The determination of whether an impairment in value of our debt securities is other than temporary is based largely on our evaluation of the issuer ' s creditworthiness. We must apply considerable judgment in determining the likelihood of the security recovering in value while we own it. Factors that may influence this include the overall level of interest rates, credit spreads, the credit quality of the underlying issuer, and other factors. This process requires consideration of risks which can be controlled to a certain extent, such as credit risk, and risks which cannot be controlled, such as interest rate risk. If, after monitoring and analyses, management believes that fair value will not recover to amortized cost prior to the disposal of the security, we recognize an other-than-temporary impairment of the security. Once a security is considered to be other-than-temporarily impaired, the impairment loss is separated into two separate components: the portion of the impairment related to credit and the portion of the impairment related to factors other than credit. We recognize a charge to earnings for the credit-related portion of other-than-temporary impairments. Impairments related to factors other than credit are charged to earnings in the event we intend to sell the security prior to the recovery of its amortized cost or if it is more likely than not that we would be required to dispose of the security prior to recovery of its amortized cost; otherwise, non-credit-related other-than-temporary impairments are charged to other comprehensive income. Our investments in perpetual securities that are rated below investment grade and equity securities are evaluated for other-than-temporary impairment under our equity impairment model. Our equity impairment model focuses on the severity of a security's decline in fair value coupled with the length of time the fair value of the security has been below amortized cost and the financial condition and near-term prospects of the issuer. For equity securities that have declines in value that are deemed to be temporary, we make an assertion as to our ability and intent to retain the security until recovery. Once identified, these equity securities are restricted from trading unless authorized based upon events that could not have been foreseen at the time we asserted our ability and intent to retain the security until recovery. If management believes that the equity security will not recover prior to the disposal of the security, we recognize an other-than-temporary impairment of the security. Once an equity security is considered to be other-than-temporarily impaired, its fair value on that date becomes the new cost basis and the impairment loss is recognized in earnings. We lend fixed-maturity securities to financial institutions in short-term security lending transactions. These securities continue to be carried as investment assets on our balance sheet during the terms of the loans and are not reported as sales. We receive cash or other securities as collateral for such loans. For loans involving unrestricted cash or securities as collateral, the collateral is reported as an asset with a corresponding liability for the return of the collateral. Other investments include policy loans, middle market loans, and other short-term investments with maturities of one year or less, but greater than 90 days, at the time of purchase and are stated at amortized cost, which approximates estimated fair value. We invest in middle market loans through participation rights that are accounted for as loan receivables and recorded at amortized cost on the acquisition date. Since we have the intent and ability to hold these loan receivables for the foreseeable future or until they mature, they are considered held for investment and are carried at adjusted amortized cost in the other investments line on our consolidated balance sheets. The adjusted amortized cost of the loan receivables reflects allowances for expected incurred losses estimated based on past events and current economic conditions as of each reporting date. Derivatives and Hedging:  Freestanding derivative instruments are reported in the consolidated balance sheet at fair value and are reported in other assets and other liabilities, with changes in value reported in earnings and/or other comprehensive income. These freestanding derivatives are interest rate swaps, foreign currency swaps, credit default swaps (CDSs), foreign currency forwards, foreign currency options, and options on interest rate swaps (or interest rate swaptions). Interest rate and foreign currency swaps are used within VIEs to hedge the risk arising from interest rate and currency exchange risk, while the CDSs are used to increase the yield and improve the diversification of the portfolio. Foreign currency forwards and options are used in hedging foreign exchange risk on U.S. dollar-denominated securities in Aflac Japan's portfolio. Foreign currency forwards and options are used to hedge certain portions of forecasted cash flows denominated in yen. Interest rate swaps are used to hedge the variability of interest cash flows associated with our variable interest rate notes. Cross-currency interest rate swaps, also referred to as foreign currency swaps, are used to economically convert certain U.S. dollar-denominated note obligations into yen-denominated principal and interest obligations. Interest rate swaptions have been used to hedge interest rate risk for certain U.S. dollar-denominated available-for-sale securities. We do not use derivatives for trading purposes, nor do we engage in leveraged derivative transactions. From time to time, we purchase certain investments that contain an embedded derivative. We assess whether this embedded derivative is clearly and closely related to the asset that serves as its host contract. If we deem that the embedded derivative's terms are not clearly and closely related to the host contract, and a separate instrument with the same terms would qualify as a derivative instrument, the derivative is separated from that contract, held at fair value and reported with the host instrument in the consolidated balance sheet, with changes in fair value reported in earnings. If we have elected the fair value option, the embedded derivative is not bifurcated, and the entire investment is held at fair value with changes in fair value reported in earnings. For those relationships where we seek hedge accounting, we formally document all relationships between hedging instruments and hedged items, as well as our risk-management objectives and strategies for undertaking various hedge transactions. This process includes linking derivatives and non-derivative financial instruments that are designated as hedges to specific assets or liabilities on the balance sheet. We also assess, both at inception and on an ongoing basis, whether the derivatives and non-derivative financial instruments used in hedging activities are highly effective in offsetting changes in fair values or cash flows of the hedged items. The assessment of hedge effectiveness determines the accounting treatment of noncash changes in fair value. Changes in the fair value of any of our derivatives that are designated and qualify as cash flow hedges are recorded in other comprehensive income as long as they are deemed effective. Any hedge ineffectiveness is recorded immediately in current period earnings within derivative and other gains (losses). Periodic derivative net coupon settlements are recorded in the line item of the consolidated statements of earnings in which the cash flows of the hedged item are recorded. Changes in the estimated fair value of derivative instruments that are designated and qualify as fair value hedges, including amounts measured as ineffectiveness, and changes in the estimated fair value of the hedged item related to the designated risk being hedged, are reported in current earnings within derivative and other gains (losses). We have designated the majority of the Parent Company's yen-denominated liabilities (Samurai and Uridashi notes and yen-denominated loans) as non-derivative hedges and designated certain derivatives as hedges of the foreign currency exposure to our investment in Aflac Japan. At the beginning of each quarter, we make our net investment hedge designation. If the total of the designated Parent Company non-derivative and derivatives notional is equal to or less than our net investment in Aflac Japan, the hedge is deemed to be effective, and the exchange effect on the yen-denominated liabilities and the change in estimated fair value of the derivatives are reported in the unrealized foreign currency component of other comprehensive income. Should these designated net investment hedge positions exceed our net investment in Aflac Japan, the foreign exchange effect on the portion that exceeds our investment in Aflac Japan would be recognized in current earnings within derivative and other gains (losses). Derivatives that are not designated as hedges are carried at fair value with all changes in fair value recorded in current period earnings within derivative and other gains (losses). We include the fair value of all freestanding derivatives in either other assets or other liabilities on the balance sheet. We receive and pledge cash or other securities as collateral on open derivative positions. Cash received as collateral is reported as an asset with a corresponding liability for the return of the collateral. Cash pledged as collateral is recorded as a reduction to cash, and a corresponding receivable is recognized for the return of the cash collateral. We generally can repledge or resell collateral obtained by us, although we do not typically exercise such rights. Securities received as collateral are not recognized unless we were to exercise our right to sell that collateral or exercise remedies on that collateral upon a counterparty default. Securities that we have pledged as collateral continue to be carried as investment assets on our balance sheet. Deferred Policy Acquisition Costs: Certain direct and incremental costs of acquiring new business are deferred and amortized with interest over the premium payment periods in proportion to the ratio of annual premium income to total anticipated premium income. Anticipated premium income is estimated by using the same mortality, persistency and interest assumptions used in computing liabilities for future policy benefits. In this manner, the related acquisition expenses are matched with revenues. Deferred costs include the excess of current-year commissions over ultimate renewal-year commissions and certain incremental direct policy issue, underwriting and sales expenses. All of these incremental costs are directly related to successful policy acquisition. For some products, policyholders can elect to modify product benefits, features, rights or coverages by exchanging a contract for a new contract or by amendment, endorsement, or rider to a contract, or by the election of a feature or coverage within a contract. These transactions are known as internal replacements. For internal replacement transactions where the resulting contract is substantially unchanged, the policy is accounted for as a continuation of the replaced contract. Unamortized deferred acquisition costs from the original policy continue to be amortized over the expected life of the new policy, and the costs of replacing the policy are accounted for as policy maintenance costs and expensed as incurred. Internal replacement transactions that result in a policy that is not substantially unchanged are accounted for as an extinguishment of the original policy and the issuance of a new policy. Unamortized deferred acquisition costs on the original policy that was replaced are immediately expensed, and the costs of acquiring the new policy are capitalized and amortized in accordance with our accounting policies for deferred acquisition costs. We measure the recoverability of DAC and the adequacy of our policy reserves annually by performing gross premium valuations on our business. Our testing indicates that our DAC is recoverable and our policy liabilities are adequate. (See the following discussion for further information regarding policy liabilities.) Policy Liabilities:  Future policy benefits represent claims that are expected to occur in the future and are computed by a net level premium method using estimated future investment yields, persistency and recognized morbidity and mortality tables modified to reflect our experience, including a provision for adverse deviation. These assumptions are generally established at the time a policy is issued. Unpaid policy claims are estimates computed on an undiscounted basis using statistical analyses of historical claims experience adjusted for current trends and changed conditions. The ultimate liability may vary significantly from such estimates. We regularly adjust these estimates as new claims experience emerges and reflect the changes in operating results in the year such adjustments are made. Other policy liabilities consist primarily of discounted advance premiums on deposit from policyholders in conjunction with their purchase of certain Aflac Japan limited-pay insurance products. These advanced premiums are deferred upon collection and recognized as premium revenue over the contractual premium payment period. For internal replacements that are determined to not be substantially unchanged, policy liabilities related to the original policy that was replaced are immediately released, and policy liabilities are established for the new insurance contract. Reinsurance: We enter into reinsurance agreements with other companies in the normal course of business. For each of our reinsurance agreements, we determine if the agreement provides indemnification against loss or liability relating to insurance risk in accordance with applicable accounting standards. Reinsurance premiums and benefits paid or provided are accounted for on bases consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Premiums, benefits and DAC are reported net of insurance ceded. See Note 8 of the Notes to the Consolidated Financial Statements for additional information. Income Taxes: Income tax provisions are generally based on pretax earnings reported for financial statement purposes, which differ from those amounts used in preparing our income tax returns. Deferred income taxes are recognized for temporary differences between the financial reporting basis and income tax basis of assets and liabilities, based on enacted tax laws and statutory tax rates applicable to the periods in which we expect the temporary differences to reverse. We record deferred tax assets for tax positions taken based on our assessment of whether the tax position is more likely than not to be sustained upon examination by taxing authorities. A valuation allowance is established for deferred tax assets when it is more likely than not that an amount will not be realized. As discussed in the Translation of Foreign Currencies section above, Aflac Japan maintains certain dollar-denominated investments that, prior to October 1, 2013, did not have any foreign currency translation adjustments recognized in other comprehensive income. However, the deferred tax expense or benefit associated with foreign exchange gains or losses on these investments is recognized in other comprehensive income (loss) until the securities mature or are sold. Total income tax expense (benefit) related to items of other comprehensive income (loss) included a deferred tax expense of $614 million in 2013 for these U.S. dollar-denominated investments. Excluding these amounts from total taxes on other comprehensive income would result in an effective income tax rate on pretax other comprehensive income (loss) of 31% in 2013. Policyholder Protection Corporation and State Guaranty Association Assessments: In Japan, the government has required the insurance industry to contribute to a policyholder protection corporation. We recognize a charge for our estimated share of the industry's obligation once it is determinable. We review the estimated liability for policyholder protection corporation contributions on an annual basis and report any adjustments in Aflac Japan's expenses. In the United States, each state has a guaranty association that supports insolvent insurers operating in those states. To date, our state guaranty association assessments have not been material. Treasury Stock: Treasury stock is reflected as a reduction of shareholders' equity at cost. We use the weighted-average purchase cost to determine the cost of treasury stock that is reissued. We include any gains and losses in additional paid-in capital when treasury stock is reissued. Share-Based Compensation: We measure compensation cost related to our share-based payment transactions at fair value on the grant date, and we recognize those costs in the financial statements over the vesting period during which the employee provides service in exchange for the award. Earnings Per Share: We compute basic earnings per share (EPS) by dividing net earnings by the weighted-average number of unrestricted shares outstanding for the period. Diluted EPS is computed by dividing net earnings by the weighted-average number of shares outstanding for the period plus the shares representing the dilutive effect of share-based awards. Reclassifications: Certain reclassifications have been made to prior-year amounts to conform to current-year reporting classifications. These reclassifications had no impact on net earnings or total shareholders' equity. New Accounting Pronouncements Recently Adopted Accounting Pronouncements Income Statement - Extraordinary and Unusual Items - Simplifying income statement presentation by eliminating the concept of extraordinary items: In January 2015, the FASB issued updated guidance that eliminates from U.S. GAAP the concept of extraordinary items. Presentation and disclosure guidance for items that are unusual in nature or occur infrequently will be retained. The amendments in this updated guidance are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted provided that the guidance is applied from the beginning of the fiscal year of adoption. We adopted this guidance as of January 1, 2015. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures. Receivables - Troubled debt restructurings by creditors - classification of certain government-guaranteed mortgage loans upon foreclosure: In August 2014, the FASB issued updated guidance for troubled debt restructurings affecting creditors that hold government guaranteed mortgage loans. The guidance requires that a mortgage loan be derecognized and a separate other receivable be recognized upon foreclosure if certain conditions are met. We adopted the guidance as of January 1, 2015. The adoption of this

BUSINESS SEGMENT AND FOREIGN IN

BUSINESS SEGMENT AND FOREIGN INFORMATION	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
BUSINESS SEGMENT INFORMATION	BUSINESS SEGMENT AND FOREIGN INFORMATION The Company consists of two reportable insurance business segments: Aflac Japan and Aflac U.S., both of which sell supplemental health and life insurance. Operating business segments that are not individually reportable and business activities, including reinsurance retrocession activities, not included in Aflac Japan or Aflac U.S. are included in the "Other business segments" category. We do not allocate corporate overhead expenses to business segments. We evaluate and manage our business segments using a financial performance measure called pretax operating earnings. Our definition of operating earnings includes interest cash flows associated with notes payable and excludes the following items from net earnings on an after-tax basis: realized investment gains/losses (securities transactions, impairments, and the impact of derivative and hedging activities), nonrecurring items and other non-operating income (loss). We then exclude income taxes related to operations to arrive at pretax operating earnings. Information regarding operations by segment for the years ended December 31 follows: (In millions) 2015 2014 2013 Revenues: Aflac Japan: Net earned premiums: Cancer $ 4,933 $ 5,596 $ 6,123 Medical and other health 3,092 3,770 4,282 Life insurance 4,021 4,495 4,577 Net investment income 2,436 2,662 2,651 Other income 31 32 55 Total Aflac Japan 14,513 16,555 17,688 Aflac U.S.: Net earned premiums: Accident/disability 2,391 2,303 2,284 Cancer 1,293 1,279 1,283 Other health 1,395 1,371 1,334 Life insurance 268 258 252 Net investment income 678 645 632 Other income 8 3 6 Total Aflac U.S. 6,033 5,859 5,791 Other business segments 225 43 49 Total business segment revenues 20,771 22,457 23,528 Realized investment gains (losses) (1) 55 171 389 Corporate 282 281 302 Intercompany eliminations (201 ) (248 ) (308 ) Other non-operating income (loss) (35 ) (2) 67 28 Total revenues $ 20,872 $ 22,728 $ 23,939 (1) Excluding a gain of $85 in 2015, $44 in 2014 and $10 in 2013 related to the interest rate component of the change in fair value of foreign currency swaps on notes payable which is classified as an operating gain when analyzing segment operations (2) Includes a loss of $20 related to the change in value of yen repatriation received in advance of settlement of certain foreign currency derivatives. The loss was offset by derivative gains included in realized investment gains (losses). (In millions) 2015 2014 2013 Pretax earnings: Aflac Japan $ 3,175 $ 3,458 $ 3,628 Aflac U.S. 1,101 1,073 1,038 Other business segments 14 (2 ) (1 ) Total business segment pretax operating earnings 4,290 4,529 4,665 Interest expense, noninsurance operations (146 ) (198 ) (198 ) Corporate and eliminations (71 ) (78 ) (68 ) Pretax operating earnings 4,073 4,253 4,399 Realized investment gains (losses) (1) 55 171 389 Other non-operating income (loss) (266 ) (2),(3) 67 28 Total earnings before income taxes $ 3,862 $ 4,491 $ 4,816 Income taxes applicable to pretax operating earnings $ 1,403 $ 1,456 $ 1,512 Effect of foreign currency translation on operating earnings (198 ) (117 ) (357 ) (1) Excluding a gain of $85 in 2015, $44 in 2014 and $10 in 2013 related to the interest rate component of the change in fair value of foreign currency swaps on notes payable which is classified as an operating gain when analyzing segment operations (2) Includes a loss of $20 related to the change in value of yen repatriation received in advance of settlement of certain foreign currency derivatives. This loss was offset by derivative gains included in realized investment gains (losses). (3) Includes expense of $230 for the make-whole payment associated with the early extinguishment of debt Assets as of December 31 were as follows: (In millions) 2015 2014 2013 Assets: Aflac Japan $ 97,646 $ 98,525 $ 102,973 Aflac U.S. 18,537 18,383 16,112 Other business segments 188 128 155 Total business segment assets 116,371 117,036 119,240 Corporate 23,415 24,636 19,909 Intercompany eliminations (21,490 ) (21,905 ) (17,842 ) Total assets $ 118,296 $ 119,767 $ 121,307 Yen-Translation Effects:  The following table shows the yen/dollar exchange rates used for or during the periods ended December 31 . Exchange effects were calculated using the same yen/dollar exchange rate for the current year as for each respective prior year. 2015 2014 2013 Statements of Earnings: Weighted-average yen/dollar exchange rate 120.99 105.46 97.54 Yen percent strengthening (weakening) (12.8 )% (7.5 )% (18.2 )% Exchange effect on pretax operating earnings (in millions) $ (288 ) $ (180 ) $ (534 ) 2015 2014 Balance Sheets: Yen/dollar exchange rate at December 31 120.61 120.55 Yen percent strengthening (weakening) (.05 )% (12.6 )% Exchange effect on total assets (in millions) $ (36 ) $ (10,706 ) Exchange effect on total liabilities (in millions) (41 ) (12,025 ) Transfers of funds from Aflac Japan:  Aflac Japan makes payments to the Parent Company for management fees and to Aflac U.S. for allocated expenses and profit repatriations. Information on transfers for each of the years ended December 31 is shown below. See Note 13 for information concerning restrictions on transfers from Aflac Japan. (In millions) 2015 2014 2013 Management fees $ 53 $ 39 $ 37 Allocated expenses 101 71 74 Profit repatriation 2,139 1,704 771 Total transfers from Aflac Japan $ 2,293 $ 1,814 $ 882 Property and Equipment:  The costs of buildings, furniture and equipment are depreciated principally on a straight-line basis over their estimated useful lives (maximum of 50 years for buildings and 20 years for furniture and equipment). Expenditures for maintenance and repairs are expensed as incurred; expenditures for betterments are capitalized and depreciated. Classes of property and equipment as of December 31 were as follows: (In millions) 2015 2014 Property and equipment: Land $ 166 $ 168 Buildings 400 393 Equipment and furniture 329 305 Total property and equipment 895 866 Less accumulated depreciation 468 437 Net property and equipment $ 427 $ 429 Receivables:  Receivables consist primarily of monthly insurance premiums due from individual policyholders or their employers for payroll deduction of premiums, net of an allowance for doubtful accounts. At December 31, 2015 , $257 million , or 36.4% of total receivables, were related to Aflac Japan's operations, compared with $386 million , or 45.8% , at December 31, 2014 .

INVESTMENTS

INVESTMENTS	12 Months Ended
	Dec. 31, 2015
Investments [Abstract]
INVESTMENTS	INVESTMENTS Net Investment Income The components of net investment income for the years ended December 31 were as follows: (In millions) 2015 2014 2013 Fixed-maturity securities $ 3,094 $ 3,249 $ 3,210 Perpetual securities 114 141 153 Equity securities and other 18 7 7 Short-term investments and cash equivalents 4 2 1 Gross investment income 3,230 3,399 3,371 Less investment expenses 95 80 78 Net investment income $ 3,135 $ 3,319 $ 3,293 Investment Holdings The amortized cost for our investments in debt and perpetual securities, the cost for equity securities and the fair values of these investments at December 31 are shown in the following tables. 2015 (In millions) Cost or Gross Gross Fair Securities available for sale, carried at fair value: Fixed maturities: Yen-denominated: Japan government and agencies $ 17,293 $ 1,862 $ 0 $ 19,155 Municipalities 128 9 0 137 Mortgage- and asset-backed securities 322 33 0 355 Public utilities 1,400 210 10 1,600 Sovereign and supranational 791 180 0 971 Banks/financial institutions 2,321 325 105 2,541 Other corporate 3,337 448 33 3,752 Total yen-denominated 25,592 3,067 148 28,511 Dollar-denominated: U.S. government and agencies 110 11 0 121 Municipalities 926 151 6 1,071 Mortgage- and asset-backed securities 200 27 0 227 Public utilities 5,464 636 221 5,879 Sovereign and supranational 331 105 0 436 Banks/financial institutions 2,865 634 21 3,478 Other corporate 25,154 1,774 1,302 25,626 Total dollar-denominated 35,050 3,338 1,550 36,838 Total fixed maturities 60,642 6,405 1,698 65,349 Perpetual securities: Yen-denominated: Banks/financial institutions 1,581 143 93 1,631 Other corporate 183 22 0 205 Dollar-denominated: Banks/financial institutions 77 35 1 111 Total perpetual securities 1,841 200 94 1,947 Equity securities: Yen-denominated 472 19 4 487 Dollar-denominated 8 3 0 11 Total equity securities 480 22 4 498 Total securities available for sale $ 62,963 $ 6,627 $ 1,796 $ 67,794 2015 (In millions) Cost or Gross Gross Fair Securities held to maturity, carried at amortized cost: Fixed maturities: Yen-denominated: Japan government and agencies $ 20,004 $ 3,387 $ 0 $ 23,391 Municipalities 341 74 0 415 Mortgage- and asset-backed securities 36 2 0 38 Public utilities 3,092 205 94 3,203 Sovereign and supranational 2,555 182 26 2,711 Banks/financial institutions 4,431 168 53 4,546 Other corporate 3,000 260 44 3,216 Total yen-denominated 33,459 4,278 217 37,520 Total securities held to maturity $ 33,459 $ 4,278 $ 217 $ 37,520 2014 (In millions) Cost or Gross Gross Fair Securities available for sale, carried at fair value: Fixed maturities: Yen-denominated: Japan government and agencies $ 17,341 $ 1,740 $ 0 $ 19,081 Municipalities 88 9 0 97 Mortgage- and asset-backed securities 351 35 0 386 Public utilities 1,691 226 5 1,912 Sovereign and supranational 799 163 0 962 Banks/financial institutions 2,752 325 189 2,888 Other corporate 3,479 531 48 3,962 Total yen-denominated 26,501 3,029 242 29,288 Dollar-denominated: U.S. government and agencies 100 17 0 117 Municipalities 961 201 2 1,160 Mortgage- and asset-backed securities 185 31 0 216 Public utilities 5,061 960 36 5,985 Sovereign and supranational 343 111 0 454 Banks/financial institutions 2,943 775 8 3,710 Other corporate 22,291 2,682 330 24,643 Total dollar-denominated 31,884 4,777 376 36,285 Total fixed maturities 58,385 7,806 618 65,573 Perpetual securities: Yen-denominated: Banks/financial institutions 2,132 223 92 2,263 Other corporate 183 48 0 231 Dollar-denominated: Banks/financial institutions 125 50 0 175 Total perpetual securities 2,440 321 92 2,669 Equity securities: Yen-denominated 10 7 0 17 Dollar-denominated 9 2 0 11 Total equity securities 19 9 0 28 Total securities available for sale $ 60,844 $ 8,136 $ 710 $ 68,270 2014 (In millions) Cost or Gross Gross Fair Securities held to maturity, carried at amortized cost: Fixed maturities: Yen-denominated: Japan government and agencies $ 20,023 $ 3,195 $ 0 $ 23,218 Municipalities 346 71 0 417 Mortgage- and asset-backed securities 43 3 0 46 Public utilities 3,342 281 20 3,603 Sovereign and supranational 2,556 272 14 2,814 Banks/financial institutions 4,932 231 78 5,085 Other corporate 3,000 326 12 3,314 Total yen-denominated 34,242 4,379 124 38,497 Total securities held to maturity $ 34,242 $ 4,379 $ 124 $ 38,497 The methods of determining the fair values of our investments in fixed-maturity securities, perpetual securities and equity securities are described in Note 5. During the third and fourth quarters of 2015, we increased our investment in yen-denominated publicly traded equity securities, including new investments in exchange traded funds (ETFs) holding Japan real estate investment trusts. These securities are classified as available for sale and carried on our balance sheet at fair value. As of December 31, 2015, the fair value of our investment in yen-denominated publicly traded equity securities was $485 million . During 2015, we did not reclassify any investments from the held-to-maturity category to the available-for-sale category. During 2014, we reclassified three investments from the held-to-maturity category to the available-for-sale category as a result of the issuers being downgraded to below investment grade. At the time of the transfer, the securities had an aggregate amortized cost of $424 million and an aggregate unrealized loss of $54 million . During 2013, we reclassified two investments from the held-to-maturity category to the available-for-sale category as a result of the issuer being downgraded to below investment grade. At the time of the transfer, the securities had an aggregate amortized cost of $492 million and an aggregate unrealized loss of $153 million . Contractual and Economic Maturities The contractual maturities of our investments in fixed maturities at December 31, 2015 , were as follows: Aflac Japan Aflac U.S. (In millions) Amortized Fair Amortized Fair Available for sale: Due in one year or less $ 130 $ 142 $ 23 $ 24 Due after one year through five years 2,617 2,984 648 709 Due after five years through 10 years 11,543 11,642 2,105 2,177 Due after 10 years 33,608 37,112 9,049 9,569 Mortgage- and asset-backed securities 372 424 35 43 Total fixed maturities available for sale $ 48,270 $ 52,304 $ 11,860 $ 12,522 Held to maturity: Due in one year or less 316 320 0 0 Due after one year through five years 1,692 1,775 0 0 Due after five years through 10 years 1,613 1,732 0 0 Due after 10 years 29,802 33,655 0 0 Mortgage- and asset-backed securities 36 38 0 0 Total fixed maturities held to maturity $ 33,459 $ 37,520 $ 0 $ 0 At December 31, 2015 , the Parent Company and other business segments had portfolios of available-for-sale fixed-maturity securities totaling $512 million at amortized cost and $523 million at fair value, which are not included in the table above. Expected maturities may differ from contractual maturities because some issuers have the right to call or prepay obligations with or without call or prepayment penalties. The majority of our perpetual securities are subordinated to other debt obligations of the issuer, but rank higher than the issuer's equity securities. Perpetual securities have characteristics of both debt and equity investments, along with unique features that create economic maturity dates for the securities. Although perpetual securities have no contractual maturity date, they have stated interest coupons that were fixed at their issuance and subsequently change to a floating short-term interest rate after some period of time. The instruments are generally callable by the issuer at the time of changing from a fixed coupon rate to a new variable rate of interest, which is determined by the combination of some market index plus a fixed amount of basis points. The net effect is to create an expected maturity date for the instrument. The economic maturities of our investments in perpetual securities, which were all reported as available for sale at December 31, 2015 , were as follows: Aflac Japan Aflac U.S. (In millions) Amortized Fair Amortized Fair Due in one year or less $ 301 $ 282 $ 0 $ 0 Due after one year through five years 292 315 0 0 Due after 10 years 1,209 1,293 39 57 Total perpetual securities available for sale $ 1,802 $ 1,890 $ 39 $ 57 Investment Concentrations Our process for credit-related investments begins with an independent approach to underwriting each issuer's fundamental credit quality. We evaluate independently those factors which we believe could influence an issuer's ability to make payments under the contractual terms of our instruments. This includes a thorough analysis of a variety of items including the issuer's country of domicile (including political, legal, and financial considerations); the industry in which the issuer competes (with an analysis of industry structure, end-market dynamics, and regulation); company specific issues (such as management, assets, earnings, cash generation, and capital needs); and contractual provisions of the instrument (such as financial covenants and position in the capital structure). We further evaluate the investment considering broad business and portfolio management objectives, including asset/liability needs, portfolio diversification, and expected income. Investment exposures that individually exceeded 10% of shareholders' equity as of December 31 were as follows: 2015 2014 (In millions) Credit Amortized Fair Credit Amortized Fair Japan National Government (1) A $36,859 $42,025 A $37,021 $41,878 (1) JGBs or JGB-backed securities Banks and Financial Institutions One of our largest investment sector concentrations as of December 31, 2015 , was banks and financial institutions. Within the countries we approve for investment opportunities, we primarily invest in financial institutions that are strategically crucial to each approved country's economy. The bank and financial institution sector is a highly regulated industry and plays a strategic role in the global economy. Our total investments in the bank and financial institution sector as of December 31 , including those classified as perpetual securities, were as follows: 2015 2014 Total Investments in Percentage of Total Investments in Percentage of Fixed maturities: Amortized cost $ 9,617 10 % $ 10,627 11 % Fair value 10,565 10 11,683 11 Perpetual securities: Upper Tier II: Amortized cost $ 1,217 1 % $ 1,554 2 % Fair value 1,265 1 1,645 1 Tier I: Amortized cost 441 0 703 1 Fair value 477 0 793 1 Total: Amortized cost $ 11,275 11 % $ 12,884 14 % Fair value 12,307 11 14,121 13 Realized Investment Gains and Losses Information regarding pretax realized gains and losses from investments for the years ended December 31 follows: (In millions) 2015 2014 2013 Realized investment gains (losses) on securities: Fixed maturities: Available for sale: Gross gains from sales $ 224 $ 192 $ 316 Gross losses from sales (8 ) (12 ) (87 ) Net gains (losses) from redemptions 52 34 34 Other-than-temporary impairment losses (152 ) (31 ) (128 ) Held to maturity: Net gains (losses) from redemptions 0 1 0 Total fixed maturities 116 184 135 Perpetual securities: Available for sale: Gross losses from sales 0 0 (1 ) Net gains (losses) from redemptions 35 0 0 Other-than-temporary impairment losses 0 0 (70 ) Total perpetual securities 35 0 (71 ) Equity securities: Other-than-temporary impairment losses (1 ) 0 (1 ) Total equity securities (1 ) 0 (1 ) Derivatives and other: Derivative gains (losses) (10 ) 31 326 Other 0 0 10 Total derivatives and other (10 ) 31 336 Total realized investment gains (losses) $ 140 $ 215 $ 399 Other-than-temporary Impairment The majority of our fixed maturity and perpetual security investments are evaluated for other-than-temporary impairment using our debt impairment model. Our debt impairment model focuses on the ultimate collection of the cash flows from our investments and whether we have the intent to sell or if it is more likely than not we would be required to sell the security prior to recovery of its amortized cost. The fair values of our fixed maturity and perpetual security investments fluctuate based on changes in interest rates, foreign exchange, and credit spreads in the global financial markets. Fair values can also be heavily influenced by the values of the assets of the issuer and expected ultimate recovery values upon a default, bankruptcy or other financial restructuring. Credit spreads are most impacted by the general credit environment and global market liquidity. Interest rates are driven by numerous factors including, but not limited to, supply and demand, governmental monetary actions, expectations of inflation and economic growth. We believe that fluctuations in the fair values of our investment securities related to general changes in the level of credit spreads or interest rates have little bearing on underlying credit quality of the issuer, and whether our investment is ultimately recoverable. Generally, we consider such declines in fair values to be temporary even in situations where an investment remains in an unrealized loss position for an extended period of time. In the course of our review process, we may determine that it is unlikely that our fixed maturity or perpetual security investment will recover in value within an acceptable time frame. Factors which may influence this determination include the severity of the price decline, the length of time the price has been impaired, if the price decline was driven by issuer credit deterioration, and our view of the likelihood of the security defaulting or otherwise being subject to an unfavorable restructuring. In those cases where we believe the security will not recover in price within an acceptable period of time, we consider such a decline in the investment's fair value, to the extent it is below the investment's cost or amortized cost, to be an other-than-temporary impairment of the investment and reduce the book value of the investment to its fair value. The perpetual securities we hold were largely issued by banks that are integral to the financial markets of the sovereign country of the issuer. As a result of the issuer's position within the economy of the sovereign country, our perpetual securities may be subject to a higher risk of nationalization of their issuers in connection with capital injections from an issuer's sovereign government. We cannot be assured that such capital support will extend to all levels of an issuer's capital structure. In addition, certain governments or regulators may consider imposing interest and principal payment restrictions on issuers of hybrid securities to preserve cash and preserve the issuer's capital. Beyond the cash flow impact that additional deferrals would have on our portfolio, such deferrals could result in ratings downgrades of the affected securities, which in turn could result in a reduction of fair value of the securities and increase our regulatory capital requirements. We consider these factors in our credit review process. When determining our intention to sell a security prior to recovery of its fair value to amortized cost, we evaluate facts and circumstances such as, but not limited to, future cash flow needs, decisions to reposition our security portfolio, and risk profile of individual investment holdings. We perform ongoing analyses of our liquidity needs, which includes cash flow testing of our policy liabilities, debt maturities, projected dividend payments and other cash flow and liquidity needs. Our cash flow testing includes extensive duration analysis of our investment portfolio and policy liabilities. Based on our analyses, we have concluded that we have sufficient excess cash flows to meet our liquidity needs without selling any of our investments prior to their maturity. Our investments in perpetual securities that are rated below investment grade and equity securities are evaluated for other-than-temporary impairment under our equity impairment model. Our equity impairment model focuses on the severity of a security’s decline in fair value coupled with the length of time the fair value of the security has been below cost or amortized cost and the financial condition and near-term prospects of the issuer. For equity securities, we also verify our intent to hold the securities until they recover in value. The fair value of our investments in equity securities may decline for various reasons, such as general market conditions which reflect prospects for the economy as a whole, or due to specific information pertaining to an industry or an individual company. For those equity securities evaluated for impairment under the equity impairment model that are in an unrealized loss position, if we believe the security will not recover in price within an acceptable period of time, or we do not have the intent to hold until recovery, we will record an other-than-temporary impairment of the investment and reduce the cost of the investment to its fair value on that date. The following table details our pretax other-than-temporary impairment losses by investment category that resulted from our impairment evaluation process for the years ended December 31 . (In millions) 2015 2014 2013 Perpetual securities $ 0 $ 0 $ 70 Corporate bonds 17 31 102 Bank/financial institution bonds 135 0 0 Sovereign and supranational 0 0 26 Equity securities 1 0 1 Total other-than-temporary impairment losses realized (1) $ 153 $ 31 $ 199 (1) Includes $131 and $45 for the years ended December 31, 2015 and 2013 , respectively, for credit-related impairments; $26 for the year ended December 31, 2013 for impairments due to severity and duration of decline in fair value; and $22 , $31 and $128 for the years ended December 31, 2015 , 2014 and 2013 , respectively, from change in intent to sell securities Unrealized Investment Gains and Losses Information regarding changes in unrealized gains and losses from investments for the years ended December 31 follows: (In millions) 2015 2014 2013 Changes in unrealized gains (losses): Fixed maturities: Available for sale $ (2,481 ) $ 5,629 $ (2,281 ) Transferred to held to maturity 0 (10 ) (9 ) Perpetual securities: Available for sale (123 ) 269 (129 ) Equity securities 9 5 1 Total change in unrealized gains (losses) $ (2,595 ) $ 5,893 $ (2,418 ) Effect on Shareholders' Equity The net effect on shareholders' equity of unrealized gains and losses from investment securities at December 31 was as follows: (In millions) 2015 2014 Unrealized gains (losses) on securities available for sale $ 4,831 $ 7,426 Deferred income taxes (1,845 ) (2,754 ) Shareholders’ equity, unrealized gains (losses) on investment securities $ 2,986 $ 4,672 Gross Unrealized Loss Aging The following tables show the fair values and gross unrealized losses of our available-for-sale and held-to-maturity investments that were in an unrealized loss position, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at December 31 . 2015 Total Less than 12 months 12 months or longer (In millions) Fair Unrealized Fair Unrealized Fair Unrealized Fixed Maturities: Municipalities: Dollar-denominated $ 80 $ 6 $ 80 $ 6 $ 0 $ 0 Public utilities: Dollar-denominated 2,127 221 1,689 132 438 89 Yen-denominated 1,487 104 1,062 73 425 31 Sovereign and supranational: Yen-denominated 580 26 385 13 195 13 Banks/financial institutions: Dollar-denominated 366 21 348 11 18 10 Yen-denominated 2,350 158 1,147 14 1,203 144 Other corporate: Dollar-denominated 13,430 1,302 11,068 770 2,362 532 Yen-denominated 1,151 77 343 5 808 72 Total fixed maturities 21,571 1,915 16,122 1,024 5,449 891 Perpetual securities: Dollar-denominated 6 1 0 0 6 1 Yen-denominated 645 93 216 12 429 81 Total perpetual securities 651 94 216 12 435 82 Equity securities: Yen-denominated 191 4 191 4 0 0 Total equity securities 191 4 191 4 0 0 Total $ 22,413 $ 2,013 $ 16,529 $ 1,040 $ 5,884 $ 973 2014 Total Less than 12 months 12 months or longer (In millions) Fair Unrealized Fair Unrealized Fair Unrealized Fixed Maturities: Municipalities: Dollar-denominated $ 75 $ 2 $ 53 $ 1 $ 22 $ 1 Public utilities: Dollar-denominated 1,001 36 164 7 837 29 Yen-denominated 805 25 98 1 707 24 Sovereign and supranational: Yen-denominated 359 14 0 0 359 14 Banks/financial institutions: Dollar-denominated 205 8 53 5 152 3 Yen-denominated 1,828 267 166 0 1,662 267 Other corporate: Dollar-denominated 8,072 330 1,901 62 6,171 268 Yen-denominated 1,151 60 122 2 1,029 58 Total fixed maturities 13,496 742 2,557 78 10,939 664 Perpetual securities: Yen-denominated 783 92 194 5 589 87 Total perpetual securities 783 92 194 5 589 87 Total $ 14,279 $ 834 $ 2,751 $ 83 $ 11,528 $ 751 Analysis of Securities in Unrealized Loss Positions The unrealized losses on our fixed income or perpetual securities investments have been primarily related to general market changes in interest rates, foreign exchange rates, and/or the levels of credit spreads rather than specific concerns with the issuer's ability to pay interest and repay principal. The unrealized losses on our investments in equity securities are primarily related to general market conditions which reflect prospects for the economy as a whole or due to specific information pertaining to an industry or an individual company. For any significant declines in fair value of our fixed income or perpetual securities, we perform a more focused review of the related issuers' credit profile. For corporate issuers, we evaluate their assets, business profile including industry dynamics and competitive positioning, financial statements and other available financial data. For non-corporate issuers, we analyze all sources of credit support, including issuer-specific factors. We utilize information available in the public domain and, for certain private placement issuers, from consultations with the issuers directly. We also consider ratings from Nationally Recognized Statistical Rating Organizations (NRSROs), as well as the specific characteristics of the security we own including seniority in the issuer's capital structure, covenant predictions, or other relevant features. From these reviews, we evaluate the issuers' continued ability to service our investment through payment of interest and principal. For any significant declines in fair value of our equity securities, we review the severity of the security’s decline in fair value coupled with the length of time the fair value of the security has been below cost. We also perform a more focused review of the financial condition and near-term prospects of the issuer, and determine whether we have the intent to hold the securities until they recover in value. The following table provides more information on our unrealized loss position on fixed maturities and perpetual securities as of December 31. 2015 2014 (In millions) Investments Gross Gross Investments Gross Gross Fixed Maturities: Public utilities 16 % 16 % 93 % 13 % 7 % 100 % Sovereign and supranational 3 1 100 3 2 100 Banks/financial institutions 12 9 59 14 33 31 Other corporate 66 69 86 65 47 88 Total fixed maturities 97 % 95 % 95 % 89 % Perpetual securities 3 5 100 5 11 100 Total 100 % 100 % 100 % 100 % Assuming no credit-related factors, unrealized gains and losses are expected to diminish as investments near maturity. Based on our credit analysis, we believe that the issuers of our investments in the sectors shown in the table above have the ability to service their obligations to us. Perpetual Securities The majority of our investments in Upper Tier II and Tier I perpetual securities are in highly-rated global financial institutions. Upper Tier II securities have more debt-like characteristics than Tier I securities and are senior to Tier I securities, preferred stock, and common equity of the issuer. Conversely, Tier I securities have more equity-like characteristics, but are senior to the common equity of the issuer, and they may also be senior to certain preferred shares; depending on the individual security; the issuer's capital structure and the regulatory jurisdiction of the issuer. Details of our holdings of perpetual securities as of December 31 were as follows: Perpetual Securities 2015 2014 (In millions) Credit Amortized Fair Unrealized Amortized Fair Unrealized Upper Tier II: A $ 31 $ 41 $ 10 $ 61 $ 87 $ 26 BBB 1,023 993 (30 ) 1,330 1,333 3 BB or lower 163 231 68 163 225 62 Total Upper Tier II 1,217 1,265 48 1,554 1,645 91 Tier I: BBB 395 408 13 519 556 37 BB or lower 46 69 23 184 237 53 Total Tier I 441 477 36 703 793 90 Other subordinated BB or lower 183 205 22 183 231 48 Total $ 1,841 $ 1,947 $ 106 $ 2,440 $ 2,669 $ 229 Assuming no credit-related factors develop, as investments near maturity, the unrealized gains or losses are expected to diminish. Based on our credit analysis, we believe that the issuers of our investments in these sectors have the ability to service their obligations to us. Perpetual securities that had an amortized cost of $599 million and fair value of $630 million at December 31, 2014 matured or were called during 2015. Variable Interest Entities (VIEs) As a condition to our involvement or investment in a VIE, we enter into certain protective rights and covenants that preclude changes in the structure of the VIE that would alter the creditworthiness of our investment or our beneficial interest in the VIE. Our involvement with all of the VIEs in which we have an interest is passive in nature, and we are not the arranger of these entities. We have not been involved in establishing these entities, except as it relates to our review and evaluation of the structure of these VIEs in the normal course of our investment decision-making process. Further, we are not, nor have we been, required to purchase any securities issued in the future by these VIEs. Our ownership interest in the VIEs is limited to holding the obligations issued by them. All of the VIEs in which we invest are static with respect to funding and have no ongoing forms of funding after the initial funding date. We have no direct or contingent obligations to fund the limited activities of these VIEs, nor do we have any direct or indirect financial guarantees related to the limited activities of these VIEs. We have not provided any assistance or any other type of financing support to any of the VIEs we invest in, nor do we have any intention to do so in the future. The weighted-average lives of our notes are very similar to the underlying collateral held by these VIEs where applicable. Our risk of loss related to our interests in any of our VIEs is limited to our investment in the debt securities issued by them. VIEs - Consolidated The following table presents the cost or amortized cost, fair value and balance sheet caption in which the assets and liabilities of consolidated VIEs are reported as of December 31. Investments in Consolidated Variable Interest Entities 2015 2014 (In millions) Cost or Amortized Fair Cost or Amortized Fair Assets: Fixed maturities, available for sale $ 3,739 $ 4,554 $ 3,020 $ 4,166 Perpetual securities, available for sale 255 228 405 429 Fixed maturities, held to maturity 0 0 83 84 Equity securities 363 363 0 0 Other assets 102 102 106 106 Total assets of consolidated VIEs $ 4,459 $ 5,247 $ 3,614 $ 4,785 Liabilities: Other liabilities $ 293 $ 293 $ 318 $ 318 Total liabilities of consolidated VIEs $ 293 $ 293 $ 318 $ 318 We are substantively the only investor in the consolidated VIEs listed in the table above. As the sole investor in these VIEs, we have the power to direct the activities of a variable interest entity that most significantly impact the entity's economic performance and are therefore considered to be the primary beneficiary of the VIEs that we consolidate. We also participate in substantially all of the variability created by these VIEs. The activities of these VIEs are limited to holding debt, equity, and perpetual securities and foreign currency, and/or CDSs, as appropriate, and utilizing the cash flows from these securities to service our investment. Neither we nor any of our creditors are able to obtain the underlying collateral of the VIEs unless there is an event of default or other specified event. For those VIEs that contain a swap, we are not a direct counterparty to the swap contracts and have no control over them. Our loss exposure to these VIEs is limited to our original investment. Our consolidated VIEs do not rely on outside or ongoing sources of funding to support their activities beyond the underlying collateral and swap contracts, if applicable. With the exception of our investment in senior secured bank loans (bank loans) and certain equity securities through unit trust structures, the underlying collateral assets and funding of our consolidated VIEs are generally static in nature and the underlying collateral and the reference corporate entities covered by any CDS contracts were all investment grade at the time of issuance. We invest in bank loans through unit trust structures in which we are the only investor, requiring us to consolidate these trusts. These bank loans are classified as available-for-sale fixed-maturity securities in the financial statements. As of December 31, 2015, the amortized cost and fair value of our bank loan investments was $1.4 billion . As of December 31, 2014, the amortized cost and fair value of our bank loan investments was $501 million and $579 million , respectively. During the fourth quarter of 2015, we invested in yen-denominated public equities through a unit trust structure in which we are the only investor, requiring us to consolidate the trust under U.S. GAAP. These equities are classified as available-for-sale in the financial statements. As of December 31, 2015, the amortized cost and fair value of these equities was $363 million . We are exposed to credit losses within our CDO that could result in principal losses to our investment. However, we have mitigated the risk of credit loss through the structure of the VIE, which contractually requires the subordinated tranches within the VIE to absorb the majority of the expected losses from the underlying credit default swaps. We currently own only senior mezzanine CDO tranches. Based on our statistical analysis models and the current subordination levels in our CDO, the VIE can sustain a reasonable number of defaults in the underlying reference entities in the CDS with no loss to our investment. VIEs - Not Consolidated The table below reflects the amortized cost, fair value and balance sheet caption in which our investment in VIEs not consolidated are reported as of December 31. Investments in Variable Interest Entities Not Consolidated 2015 2014 (In millions) Amortized Fair Amortized Fair Assets: Fixed maturities, available for sale $ 5,536 $ 6,027 $ 6,104 $ 6,937 Perpetual securities, available for sale 249 253 324 330 Fixed maturities, held to maturity 2,477 2,636 2,564 2,829 Total investments in VIEs not consolidated $ 8,262 $ 8,916 $ 8,992 $ 10,096 The VIEs that we are not required to consolidate are investments that are in the form of debt obligations from the VIEs that are irrevocably and unconditionally guaranteed by their corporate parents or sponsors. These VIEs are the primary financing vehicles used by their corporate sponsors to raise financing in the capital markets. The variable interests created by these VIEs are principally or solely a result of the debt instruments issued by them. We do not have the power to direct the activities that most significantly impact the entity's economic performance, nor do we have (1) the obligation to absorb losses of the entity or (2) the right to receive benefits from the entity. As such, we are not the primary beneficiary of these VIEs and are therefore not required to consolidate them. These VIE investments comprise securities from 169 separate issuers with an average credit rating of BBB . Loans and Loan Receivables Middle Market Loans As of December 31, 2015 , our investment in middle market loan receivables was $118 million , of which $53 million was unfunded, while the associated allowance for expected losses was immaterial. As of December 31, 2015 , we had commitments of $182 million to fund potential future loan originations related to this investment program. These commitments are contingent upon the availability of middle market loans that meet our underwriting criteria. Commercial Mortgage Loans During the fourth quarter of 2015, we initiated our commercial mortgage loan investment program. As of December 31, 2015 , we had not yet funded any commercial mortgage loans. O

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS	DERIVATIVE INSTRUMENTS Our freestanding derivative financial instruments consist of: (1) foreign currency swaps and credit default swaps that are associated with investments in special-purpose entities, including VIEs where we are the primary beneficiary; (2) foreign currency forwards and options used in hedging foreign exchange risk on U.S. dollar-denominated securities in Aflac Japan's portfolio; (3) foreign currency forwards and options used to hedge foreign exchange risk from our net investment in Aflac Japan and economically hedge certain portions of forecasted cash flows denominated in yen; (4) swaps associated with our notes payable, consisting of cross-currency interest rate swaps, also referred to as foreign currency swaps, associated with certain senior notes and our subordinated debentures; and (5) options on interest rate swaps (or interest rate swaptions) and futures used to hedge interest rate risk for certain available-for-sale securities. We do not use derivative financial instruments for trading purposes, nor do we engage in leveraged derivative transactions. Some of our derivatives are designated as cash flow hedges, fair value hedges or net investment hedges; however, other derivatives do not qualify for hedge accounting or we elect not to designate them as an accounting hedge. We utilize a net investment hedge to mitigate foreign exchange exposure resulting from our net investment in Aflac Japan. In addition to designating derivatives as hedging instruments, we have designated our yen-denominated Samurai and Uridashi notes and yen-denominated loans as non-derivative hedging instruments for this net investment hedge. Derivative Types We enter into foreign currency swaps pursuant to which we exchange an initial principal amount in one currency for an initial principal amount of another currency, with an agreement to re-exchange the currencies at a future date at an agreed upon exchange rate. There may also be periodic exchanges of payments at specified intervals based on the agreed upon rates and notional amounts. Foreign currency swaps are used primarily in the consolidated VIEs in our Aflac Japan portfolio to convert foreign-denominated cash flows to yen, the functional currency of Aflac Japan, in order to minimize cash flow fluctuations. We also use foreign currency swaps to economically convert certain of our dollar-denominated senior note and subordinated debenture principal and interest obligations into yen-denominated obligations. Foreign currency forwards and options with short-term maturities are executed for the Aflac Japan segment in order to hedge the currency risk on the fair value of certain fixed-maturity U.S. dollar-denominated securities. In forward transactions, Aflac Japan agrees with another party to buy a fixed amount of yen and sell a corresponding amount of U.S. dollars at a specified future date. Aflac Japan also executes foreign currency option transactions in a collar strategy, where Aflac Japan agrees with another party to simultaneously purchase a fixed amount of U.S. dollar put options and sell U.S. dollar call options. The combination of these two actions results in no net premium being paid (i.e. a costless or zero-cost collar). The foreign currency forwards and options are used in fair value hedging relationships to mitigate the foreign exchange risk associated with U.S. dollar-denominated investments supporting yen-denominated liabilities. Foreign currency forwards and options are also used to hedge the currency risk associated with the net investment in Aflac Japan. In these forward transactions, Aflac agrees with another party to buy a fixed amount of U.S. dollars and sell a corresponding amount of yen at a specified future date. In the option transactions, we use a combination of foreign currency options to protect expected future cash flows by simultaneously purchasing yen put options (options that protect against a weakening yen) and selling yen call options (options that limit participation in a strengthening yen). The combination of these two actions results in no net premium being paid (i.e. a costless or zero-cost collar). The only CDS that we currently hold relates to components of an investment in a VIE and is used to assume credit risk related to an individual security. This CDS contract entitles the consolidated VIE to receive periodic fees in exchange for an obligation to compensate the derivative counterparties should the referenced security issuer experience a credit event, as defined in the contract. Interest rate swaps involve the periodic exchange of cash flows with other parties, at specified intervals, calculated using agreed upon rates or other financial variables and notional principal amounts. Typically, at the time a swap is entered into, the cash flow streams exchanged by the counterparties are equal in value. No cash or principal payments are exchanged at the inception of the contract. Interest rate swaps are primarily used to convert interest receipts on floating-rate fixed-maturity securities contracts to fixed rates. These derivatives are predominantly used to better match cash receipts from assets with cash disbursements required to fund liabilities. Interest rate swaptions are options on interest rate swaps. Interest rate collars are combinations of two swaption positions and are executed in order to hedge certain U.S. dollar-denominated available-for-sale securities that are held in the Aflac Japan segment. We use collars to protect against significant changes in the fair value associated with interest rate changes of our U.S. dollar-denominated available-for-sale securities. In order to maximize the efficiency of the collars while minimizing cost, we set the strike price on each collar so that the premium paid for the ‘payer leg’ is offset by the premium received for having sold the ‘receiver leg’. Periodically, depending on general economic conditions, we may enter into other derivative transactions. Credit Risk Assumed through Derivatives For the foreign currency and credit default swaps associated with our VIE investments for which we are the primary beneficiary, we bear the risk of foreign exchange loss due to counterparty default even though we are not a direct counterparty to those contracts. We are a direct counterparty to the foreign currency swaps that we have entered into in connection with certain of our senior notes, subordinated debentures, and Samurai notes; foreign currency forwards; foreign currency options; and interest rate swaptions, and therefore we are exposed to credit risk in the event of nonperformance by the counterparties in those contracts. The risk of counterparty default for our VIE swaps, foreign currency swaps, certain foreign currency forwards, foreign currency options and interest rate swaptions is mitigated by collateral posting requirements that counterparties to those transactions must meet. As of December 31, 2015 , there were 15 counterparties to our derivative agreements, with five comprising 63% of the aggregate notional amount. The counterparties to these derivatives are financial institutions with the following credit ratings as of December 31: 2015 2014 (In millions) Notional Amount Asset Derivatives Liability Derivatives Notional Amount Asset Derivatives Liability Derivatives Counterparties' credit rating: AA $ 2,187 $ 166 $ (35 ) $ 1,098 $ 39 $ (36 ) A 19,940 510 (336 ) 22,564 763 (2,387 ) Total $ 22,127 $ 676 $ (371 ) $ 23,662 $ 802 $ (2,423 ) We engage in derivative transactions directly with unaffiliated third parties under International Swaps and Derivatives Association, Inc. (ISDA) agreements and other documentation. Most of the ISDA agreements also include Credit Support Annex (CSA) provisions, which generally provide for two-way collateral postings, in certain cases at the first dollar of exposure and in other cases once various rating and exposure threshold levels are triggered. We mitigate the risk that counterparties to transactions might be unable to fulfill their contractual obligations by monitoring counterparty credit exposure and collateral value while generally requiring that collateral be posted at the outset of the transaction or that additional collateral be posted upon the occurrence of certain events or circumstances. In addition, a significant portion of the derivative transactions have provisions that require collateral to be posted upon a downgrade of our long-term debt ratings or give the counterparty the right to terminate the transaction upon a downgrade of Aflac’s financial strength rating. The actual amount of collateral required to be posted to counterparties in the event of such downgrades, or the aggregate amount of payments that we could be required to make, depends on market conditions, the fair value of outstanding affected transactions, and other factors prevailing at and after the time of the downgrade. The fair value of the collateral posted by us to third parties for derivative transactions was $20 million at December 31, 2015 , which consisted of $17 million of pledged securities and $3 million of cash, compared with $1.6 billion at December 31, 2014 , which consisted entirely of pledged securities. This collateral can generally be repledged or resold by the counterparties. The aggregate fair value of all derivative instruments with credit-risk-related contingent features that were in a net liability position by counterparty was approximately $26 million and $2.1 billion as of December 31, 2015 and 2014 , respectively. If the credit-risk-related contingent features underlying these agreements had been triggered on December 31, 2015 , we estimate that we would be required to post a maximum of $6 million of additional collateral to these derivative counterparties. Collateral obtained by us from third parties for derivative transactions was $412 million and $619 million at December 31, 2015 and 2014 , respectively. We are generally allowed to sell or repledge collateral obtained from our derivative counterparties, although we do not typically exercise such rights. Accounting for Derivative Financial Instruments Freestanding derivatives are carried at estimated fair value in our consolidated balance sheets either as other assets or as other liabilities. See Note 5 for a discussion on how we determine the fair value of our derivatives. Accruals on derivatives are recorded in accrued investment income or within other liabilities in the consolidated balance sheets. If a derivative is not designated as an accounting hedge or its use in managing risk does not qualify for hedge accounting, changes in the estimated fair value of the derivative are generally reported within derivative and other gains(losses), which is a component of realized investment gains (losses). The fluctuations in estimated fair value of derivatives that have not been designated for hedge accounting can result in volatility in net earnings. Hedge Documentation and Effectiveness Testing To qualify for hedge accounting treatment, a derivative must be highly effective in mitigating the designated risk of the hedged item. At the inception of the hedging relationship for hedges we elect to designate for hedge accounting treatment, we formally document all relationships between hedging instruments and hedged items, as well as our risk-management objective and strategy for undertaking each hedge transaction. We document the designation of each hedge as either (i) a hedge of the variability of cash flows to be received or paid related to a recognized asset or liability or the hedge of a forecasted transaction ("cash flow hedge"); (ii) a hedge of the estimated fair value of a recognized asset or liability ("fair value hedge"); or (iii) a hedge of a net investment in a foreign operation. The documentation process includes linking derivatives and nonderivatives that are designated as hedges to specific assets or groups of assets or liabilities on the statement of financial position or to specific forecasted transactions and defining the effectiveness and ineffectiveness testing methods to be used. At the hedge's inception and on an ongoing quarterly basis, we also formally assess whether the derivatives that are used in hedging transactions have been, and are expected to continue to be, highly effective in offsetting their designated risk. Hedge effectiveness is assessed using qualitative and quantitative methods. For assessing hedge effectiveness of cash flow hedges, qualitative methods may include the comparison of critical terms of the derivative to the hedged item, and quantitative methods may include regression or other statistical analysis of changes in cash flows associated with the hedge relationship. Hedge ineffectiveness of the hedge relationships on our VIE cash flow hedges is measured each reporting period using the “Hypothetical Derivative Method.” For derivative instruments that are designated and qualify as cash flow hedges, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income (loss) and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. Gains and losses on the derivative representing hedge ineffectiveness are recognized in current earnings within derivative and other gains (losses). All components of each derivative's gain or loss are included in the assessment of hedge effectiveness. For assessing hedge effectiveness of fair value hedges, qualitative methods may include the comparison of critical terms of the derivative to the hedged item, and quantitative methods may include regression or other statistical analysis of changes in fair value associated with the hedge relationship. Hedge ineffectiveness of the hedge relationships is measured each reporting period using the dollar offset method. For derivative instruments that are designated and qualify as fair value hedges, changes in the estimated fair value of the derivative, including amounts measured as ineffectiveness, and changes in the estimated fair value of the hedged item related to the designated risk being hedged, are reported in current earnings within derivative and other gains (losses). When assessing the effectiveness of our fair value hedges, we exclude the changes in fair value related to the difference between the spot and the forward rate on our foreign currency forwards and the time value of options. For the hedge of our net investment in Aflac Japan, we have designated Parent Company yen-denominated liabilities as non-derivative hedging instruments and have designated certain foreign currency forwards and options as derivative hedging instruments. We make our net investment hedge designation at the beginning of each quarter. For assessing hedge effectiveness of net investment hedges, if the total of the designated Parent Company non-derivative and derivatives notional is equal to or less than our net investment in Aflac Japan, the hedge is deemed to be effective. If the hedge is effective, the related exchange effect on the yen-denominated liabilities is reported in the unrealized foreign currency component of other comprehensive income. For derivatives designated as net investment hedges, Aflac follows the forward-rate method. According to that method, all changes in fair value, including changes related to the forward-rate component of foreign currency forward contracts and the time value of foreign currency options, are reported in the unrealized foreign currency component of other comprehensive income. Should these designated net investment hedge positions exceed our net investment in Aflac Japan, the foreign exchange effect on the portion that exceeds our investment in Aflac Japan would be recognized in current earnings within derivative and other gains (losses). Discontinuance of Hedge Accounting We discontinue hedge accounting prospectively when (1) it is determined that the derivative is no longer highly effective in offsetting changes in the estimated cash flows or fair value of a hedged item; (2) the derivative is de-designated as a hedging instrument; or (3) the derivative expires or is sold, terminated or exercised. When hedge accounting is discontinued on a cash flow hedge or fair value hedge, the derivative is carried in the consolidated balance sheets at its estimated fair value, with changes in estimated fair value recognized in current period earnings. For discontinued cash flow hedges, including those where the derivative is sold, terminated or exercised, amounts previously deferred in other comprehensive income (loss) are reclassified into earnings when earnings are impacted by the cash flow of the hedged item. Derivative Balance Sheet Classification The tables below summarize the balance sheet classification of our derivative fair value amounts, as well as the gross asset and liability fair value amounts, at December 31. The fair value amounts presented do not include income accruals. The notional amount of derivative contracts represents the basis upon which pay or receive amounts are calculated. Notional amounts are not reflective of credit risk. 2015 (In millions) Net Derivatives Asset Liability Hedge Designation/ Derivative Type Notional Fair Value Fair Value Fair Value Cash flow hedges: Foreign currency swaps $ 75 $ (15 ) $ 0 $ (15 ) Total cash flow hedges 75 (15 ) 0 (15 ) Fair value hedges: Foreign currency forwards 13,080 45 88 (43 ) Foreign currency options 1,250 0 0 0 Total fair value hedges 14,330 45 88 (43 ) Net investment hedge: Foreign currency forwards 763 13 19 (6 ) Foreign currency options 266 (3 ) 5 (8 ) Total net investment hedge 1,029 10 24 (14 ) Non-qualifying strategies: Foreign currency swaps 6,599 264 563 (299 ) Foreign currency forwards 11 0 0 0 Credit default swaps 83 1 1 0 Total non-qualifying strategies 6,693 265 564 (299 ) Total derivatives $ 22,127 $ 305 $ 676 $ (371 ) Balance Sheet Location Other assets $ 11,413 $ 676 $ 676 $ 0 Other liabilities 10,714 (371 ) 0 (371 ) Total derivatives $ 22,127 $ 305 $ 676 $ (371 ) 2014 (In millions) Net Derivatives Asset Liability Hedge Designation/ Derivative Type Notional Fair Value Fair Value Fair Value Cash flow hedges: Foreign currency swaps $ 75 $ (15 ) $ 0 $ (15 ) Total cash flow hedges 75 (15 ) 0 (15 ) Fair value hedges: Foreign currency forwards 12,388 (1,791 ) 0 (1,791 ) Foreign currency options 697 (32 ) 0 (32 ) Interest rate swaptions 2,502 (159 ) 0 (159 ) Total fair value hedges 15,587 (1,982 ) 0 (1,982 ) Net investment hedge: Foreign currency forwards 1,307 54 56 (2 ) Total net investment hedge 1,307 54 56 (2 ) Non-qualifying strategies: Foreign currency swaps 5,765 443 746 (303 ) Foreign currency forwards 784 (119 ) 0 (119 ) Foreign currency options 53 (1 ) 0 (1 ) Credit default swaps 83 0 0 0 Interest rate swaptions 8 (1 ) 0 (1 ) Total non-qualifying strategies 6,693 322 746 (424 ) Total derivatives $ 23,662 $ (1,621 ) $ 802 $ (2,423 ) Balance Sheet Location Other assets $ 6,531 $ 802 $ 802 $ 0 Other liabilities 17,131 (2,423 ) 0 (2,423 ) Total derivatives $ 23,662 $ (1,621 ) $ 802 $ (2,423 ) Cash Flow Hedges Certain of our consolidated VIEs have foreign currency swaps that qualify for hedge accounting treatment. For those that have qualified, we have designated the derivative as a hedge of the variability in cash flows of a forecasted transaction or of amounts to be received or paid related to a recognized asset (“cash flow” hedge). We expect to continue this hedging activity for a weighted-average period of approximately 10 years. The remaining derivatives in our consolidated VIEs that have not qualified for hedge accounting have been designated as held for other investment purposes (“non-qualifying strategies”). Fair Value Hedges We designate and account for certain foreign currency forwards and options as fair value hedges when they meet the requirements for hedge accounting. These foreign currency forwards and options hedge the foreign currency exposure of certain U.S. dollar-denominated fixed maturity securities within the investment portfolio of our Aflac Japan segment. We recognize gains and losses on these derivatives and the related hedged items in current earnings within derivative and other gains (losses). The change in the fair value of the foreign currency forwards related to the changes in the difference between the spot rate and the forward price is excluded from the assessment of hedge effectiveness. The change in fair value of the foreign currency option related to the time value of the option is excluded from the assessment of hedge effectiveness. We designate and account for interest rate swaptions as fair value hedges when they meet the requirements for hedge accounting. These interest rate swaptions hedge the interest rate exposure of certain U.S. dollar-denominated fixed maturity securities within the investment portfolio of our Aflac Japan segment. We recognize gains and losses on these derivatives and the related hedged items in current earnings within derivative and other gains (losses). The change in the fair value of the interest rate swaptions related to the time value of the option is excluded from the assessment of hedge effectiveness. The following table presents the gains and losses on derivatives and the related hedged items in fair value hedges for the years ended December 31. Fair Value Hedging Relationships (In millions) Hedging Derivatives Hedged Items Hedging Derivatives Hedged Items Total Gains (Losses) Gains (Losses) Gains (Losses) Ineffectiveness 2015: Foreign currency Fixed-maturity securities $ (133 ) $ (136 ) $ 3 $ (5 ) $ (2 ) Foreign currency Fixed-maturity securities (4 ) 3 (7 ) 7 0 Interest rate Fixed-maturity securities (95 ) 19 (114 ) 99 (15 ) 2014: Foreign currency forwards Fixed-maturity securities $ (1,835 ) $ (38 ) $ (1,797 ) $ 1,819 $ 22 Foreign currency options Fixed-maturity securities (41 ) (4 ) (37 ) 38 1 Interest rate Fixed-maturity securities (318 ) (36 ) (282 ) 316 34 2013: Foreign currency Fixed-maturity securities $ (1,735 ) $ (25 ) $ (1,710 ) $ 1,700 $ (10 ) Interest rate Fixed-maturity securities 17 17 0 0 0 Net Investment Hedge Our primary exposure to be hedged is our net investment in Aflac Japan, which is affected by changes in the yen/dollar exchange rate. To mitigate this exposure, we have designated the Parent Company's yen-denominated liabilities (Samurai and Uridashi notes - see Note 9) as non-derivative hedges and designated foreign currency forwards and options as derivative hedges of the foreign currency exposure of our net investment in Aflac Japan. We used foreign exchange forwards and options to hedge foreign exchange risk on 30.0 billion yen, 102.5 billion yen, 25.0 billion yen, and 85.0 billion yen of profit repatriation received from Aflac Japan in February 2015, July 2015, September 2015, and December 2015, respectively. As of December 31, 2015 , we had entered into foreign exchange forwards and options as part of a hedge on 124.1 billion yen of future profit repatriation. Our net investment hedge was effective for the years ended December 31, 2015 , 2014 and 2013 . Non-qualifying Strategies For our derivative instruments in consolidated VIEs that do not qualify for hedge accounting treatment, all changes in their fair value are reported in current period earnings within derivative and other gains (losses). The amount of gain or loss recognized in earnings for our VIEs is attributable to the derivatives in those investment structures. While the change in value of the swaps is recorded through current period earnings, the change in value of the available-for-sale fixed maturity or perpetual securities associated with these swaps is recorded through other comprehensive income. We have cross-currency interest rate swap agreements related to our $400 million senior notes due February 2017, $550 million senior notes due March 2020, $350 million senior notes due February 2022, $700 million senior notes due June 2023, $750 million senior notes due November 2024, $450 million senior notes due March 2025, and $500 million subordinated debentures due September 2052. Changes in the values of these swaps are recorded through current period earnings. For additional information regarding these swaps, see Note 9. Impact of Derivatives and Hedging Instruments The following table summarizes the impact to realized investment gains (losses) and other comprehensive income (loss) from all derivatives and hedging instruments for the years ended December 31. 2015 2014 2013 (In millions) Realized Investment Other (1) Realized Investment Other (1) Realized Other (1) Qualifying hedges: Cash flow hedges: Foreign currency swaps $ 0 $ 0 $ (2 ) $ (17 ) $ (2 ) $ (10 ) Total cash flow hedges 0 0 (2 ) (17 ) (2 ) (10 ) Fair value hedges: Foreign currency forwards (2) (138 ) 0 (16 ) 0 (35 ) 0 Foreign currency options ( 2) 3 0 (3 ) 0 0 0 Interest rate swaptions (2) 4 0 (2 ) 0 17 0 Total fair value hedges (131 ) 0 (21 ) 0 (18 ) 0 Net investment hedge: Non-derivative hedging 0 3 0 39 0 155 Foreign currency swaps 0 0 0 0 0 (104 ) Foreign currency forwards 0 4 0 89 0 24 Foreign currency options 0 0 0 (3 ) 0 4 Total net investment hedge 0 7 0 125 0 79 Non-qualifying strategies: Foreign currency swaps 16 0 151 0 346 0 Foreign currency forwards 100 0 (11 ) 0 0 0 Foreign currency options 0 0 0 0 11 0 Credit default swaps 1 0 3 0 31 0 Interest rate swaps 5 0 (1 ) 0 (8 ) 0 Interest rate swaptions 0 0 1 0 (29 ) 0 Futures (1 ) 0 (89 ) 0 (5 ) 0 Total non- qualifying strategies 121 0 54 0 346 0 Total $ (10 ) $ 7 $ 31 $ 108 $ 326 $ 69 (1) Cash flow hedge items are recorded as unrealized gains (losses) on derivatives and net investment hedge items are recorded in the unrealized foreign currency translation gains (losses) line in the consolidated statement of comprehensive income (loss). (2) Impact shown net of effect of hedged items (see Fair Value Hedges section of this Note 4 for further detail) There was no gain or loss reclassified from accumulated other comprehensive income (loss) into earnings related to our designated cash flow hedges and net investment hedge for the years ended December 31, 2015 , 2014 and 2013 . As of December 31, 2015 , deferred gains and losses on derivative instruments recorded in accumulated other comprehensive income that are expected to be reclassified to earnings during the next twelve months were immaterial. Offsetting of Financial Instruments and Derivatives Some of the Company's derivative instruments are subject to enforceable master netting arrangements that provide for the net settlement of all derivative contracts between the Parent Company or Aflac and its respective counterparty in the event of default or upon the occurrence of certain termination events. Collateral support agreements with certain of the master netting arrangements provide that the Company will receive or pledge financial collateral in the event either minimum thresholds, or in certain cases ratings levels, have been reached. We have securities lending agreements with unaffiliated financial institutions that post collateral to us in return for the use of our fixed maturity securities (see Note 3). When we have entered into securities lending agreements with the same counterparty, the agreements generally provide for net settlement in the event of default by the counterparty. This right of set-off would allow us to keep and apply collateral received if the counterparty failed to return the securities borrowed from us as contractually agreed. For additional information on the Company's accounting policy for securities lending, see Note 1. The tables below summarize our derivatives and securities lending transactions as of December 31, and as reflected in the tables, in accordance with U.S. GAAP, our policy is to not offset these financial instruments in the Consolidated Balance Sheets. Offsetting of Financial Assets and Derivative Assets 2015 Gross Amounts Not Offset (In millions) Gross Amount of Recognized Assets Gross Amount Offset in Balance Sheet Net Amount of Assets Presented in Balance Sheet Carrying Value of Financial Instruments Collateral Received Net Amount Derivative assets: Foreign currency swaps $ 563 $ 0 $ 563 $ 0 $ (313 ) $ 250 Foreign currency forwards 107 0 107 0 (96 ) 11 Foreign currency options 5 0 5 0 (3 ) 2 Credit default swaps 1 0 1 0 0 1 Total derivative assets, subject to a master netting arrangement or offsetting arrangement 676 0 676 0 (412 ) (1) 264 Securities lending and similar arrangements 921 0 921 0 (921 ) 0 Total $ 1,597 $ 0 $ 1,597 $ 0 $ (1,333 ) $ 264 (1) Consists of $86 of pledged securities and $326 of cash. 2014 Gross Amounts Not Offset (In millions) Gross Amount of Recognized Assets Gross Amount Offset in Balance Sheet Net Amount of Assets Presented in Balance Sheet Carrying Value of Financial Instruments Collateral Received Net Amount Derivative assets: Foreign currency swaps $ 746 $ 0 $ 746 $ 0 $ (568 ) $ 178 Foreign currency forwards 56 0 56 0 (51 ) 5 Total derivative assets, subject to a master netting arrangement or offsetting arrangement 802 0 802 0 (619 ) (1) 183 Securities lending and similar arrangements 2,149 0 2,149 0 (2,149 ) 0 Total $ 2,951 $ 0 $ 2,951 $ 0 $ (2,768 ) $ 183 (1) Consists of $153 of pledged securities and $466 of cash. Offsetting of Financial Liabilities and Derivative Liabilities 2015 Gross Amounts Not Offset in Balance Sheet (In millions) Gross Amount of Recognized Liabilities Gross Amount Offset in Balance Sheet Net Amount of Liabilities Presented in Balance Sheet Carrying Value of Financial Instruments Collateral Pledged Net Amount Derivative liabilities: Foreign currency swaps $ (314 ) $ 0 $ (314 ) $ 0 $ 1 $ (313 ) Foreign currency forwards (49 ) 0 (49 ) 0 18 (31 ) Foreign currency options (8 ) 0 (8 ) 0 1 (7 ) Total derivative liabilities, subject to a master netting arrangement or offsetting arrangement (371 ) 0 (371 ) 0 20 (1) (351 ) Securities lending and similar arrangements (941 ) 0 (941 ) 921 0 (20 ) Total $ (1,312 ) $ 0 $ (1,312 ) $ 921 $ 20 $ (371 ) (1) Consists of $17 of pledged securities and $3 of cash. 2014 Gross Amounts Not Offset (In millions) Gross Amount of Recognized Liabilities Gross Amount Offset in Balance Sheet Net Amount of Liabilities Presented in Balance Sheet Carrying Value of Financial Instruments Collateral Pledged Net Amount Derivative liabilities: Foreign currency swaps $ (318 ) $ 0 $ (318 ) $ 0 $ 0 $ (318 ) Foreign currency forwards (1,912 ) 0 (1,912 ) 0 1,439 (473 ) Foreign currency options (33 ) 0 (33 ) 0 24 (9 ) Interest rate swaptions (160 ) 0 (160 ) 0 158 (2 ) Total derivative liabilities, subject to a master netting arrangement or offsetting arrangement (2,423 ) 0 (2,423 ) 0 1,621 (1) (802 ) Securities lending and similar arrangements (2,193 ) 0 (2,193 ) 2,149 0 (44 ) Total $ (4,616 ) $ 0 $ (4,616 ) $ 2,149 $ 1,621 $ (846 ) (1) Consists entirely of pledged securities. For additional information on our financial instruments, see the accompanying Notes 1, 3 and 5.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Fair Value Hierarchy U.S. GAAP specifies a hierarchy of valuation techniques based on whether the inputs to those valuation techniques are observable or unobservable. These two types of inputs create three valuation hierarchy levels. Level 1 valuations reflect quoted market prices for identical assets or liabilities in active markets. Level 2 valuations reflect quoted market prices for similar assets or liabilities in an active market, quoted market prices for identical or similar assets or liabilities in non-active markets or model-derived valuations in which all significant valuation inputs are observable in active markets. Level 3 valuations reflect valuations in which one or more of the significant inputs are not observable in an active market. The following tables present the fair value hierarchy levels of the Company's assets and liabilities that are measured and carried at fair value on a recurring basis as of December 31. 2015 (In millions) Quoted Prices in Significant Significant Total Assets: Securities available for sale, carried at Fixed maturities: Government and agencies $ 18,669 $ 607 $ 0 $ 19,276 Municipalities 0 1,208 0 1,208 Mortgage- and asset-backed securities 0 362 220 582 Public utilities 0 7,479 0 7,479 Sovereign and supranational 0 1,407 0 1,407 Banks/financial institutions 0 5,993 26 6,019 Other corporate 0 29,378 0 29,378 Total fixed maturities 18,669 46,434 246 65,349 Perpetual securities: Banks/financial institutions 0 1,742 0 1,742 Other corporate 0 205 0 205 Total perpetual securities 0 1,947 0 1,947 Equity securities 489 6 3 498 Other assets: Foreign currency swaps 0 462 101 563 Foreign currency forwards 0 107 0 107 Foreign currency options 0 5 0 5 Credit default swaps 0 0 1 1 Total other assets 0 574 102 676 Other investments 176 0 0 176 Cash and cash equivalents 4,350 0 0 4,350 Total assets $ 23,684 $ 48,961 $ 351 $ 72,996 Liabilities: Foreign currency swaps $ 0 $ 21 $ 293 $ 314 Foreign currency forwards 0 49 0 49 Foreign currency options 0 8 0 8 Total liabilities $ 0 $ 78 $ 293 $ 371 2014 (In millions) Quoted Prices in Significant Significant Total Assets: Securities available for sale, carried at Fixed maturities: Government and agencies $ 18,683 $ 515 $ 0 $ 19,198 Municipalities 0 1,257 0 1,257 Mortgage- and asset-backed securities 0 379 223 602 Public utilities 0 7,897 0 7,897 Sovereign and supranational 0 1,416 0 1,416 Banks/financial institutions 0 6,572 26 6,598 Other corporate 0 28,605 0 28,605 Total fixed maturities 18,683 46,641 249 65,573 Perpetual securities: Banks/financial institutions 0 2,289 149 2,438 Other corporate 0 231 0 231 Total perpetual securities 0 2,520 149 2,669 Equity securities 19 6 3 28 Other assets: Foreign currency swaps 0 640 106 746 Foreign currency forwards 0 56 0 56 Total other assets 0 696 106 802 Other investments 171 0 0 171 Cash and cash equivalents 4,658 0 0 4,658 Total assets $ 23,531 $ 49,863 $ 507 $ 73,901 Liabilities: Foreign currency swaps $ 0 $ 0 $ 318 $ 318 Foreign currency forwards 0 1,912 0 1,912 Foreign currency options 0 33 0 33 Interest rate swaptions 0 160 0 160 Total liabilities $ 0 $ 2,105 $ 318 $ 2,423 The following tables present the carrying amount and fair value categorized by fair value hierarchy level for the Company's financial instruments that are not carried at fair value as of December 31. 2015 (In millions) Carrying Quoted Prices in Significant Significant Total Assets: Securities held to maturity, Fixed maturities: Government and agencies $ 20,004 $ 23,391 $ 0 $ 0 $ 23,391 Municipalities 341 0 415 0 415 Mortgage and asset-backed 36 0 12 26 38 Public utilities 3,092 0 3,203 0 3,203 Sovereign and 2,555 0 2,711 0 2,711 Banks/financial institutions 4,431 0 4,546 0 4,546 Other corporate 3,000 0 3,216 0 3,216 Other investments 118 0 0 118 118 Total assets $ 33,577 $ 23,391 $ 14,103 $ 144 $ 37,638 Liabilities: Other policyholders’ funds $ 6,285 $ 0 $ 0 $ 6,160 $ 6,160 Notes payable 4,991 0 0 5,285 5,285 Total liabilities $ 11,276 $ 0 $ 0 $ 11,445 $ 11,445 2014 (In millions) Carrying Quoted Prices in Significant Significant Total Assets: Securities held to maturity, Fixed maturities: Government and agencies $ 20,023 $ 23,218 $ 0 $ 0 $ 23,218 Municipalities 346 0 417 0 417 Mortgage and asset-backed 43 0 15 31 46 Public utilities 3,342 0 3,603 0 3,603 Sovereign and 2,556 0 2,814 0 2,814 Banks/financial institutions 4,932 0 5,085 0 5,085 Other corporate 3,000 0 3,314 0 3,314 Total assets $ 34,242 $ 23,218 $ 15,248 $ 31 $ 38,497 Liabilities: Other policyholders’ funds $ 6,031 $ 0 $ 0 $ 5,905 $ 5,905 Notes payable 5,268 0 0 5,835 5,835 Total liabilities $ 11,299 $ 0 $ 0 $ 11,740 $ 11,740 Fair Value of Financial Instruments U.S. GAAP requires disclosure of the fair value of certain financial instruments including those that are not carried at fair value. The carrying amounts for cash and cash equivalents, other investments, receivables, accrued investment income, accounts payable, cash collateral and payables for security transactions approximated their fair values due to the nature of these instruments. Liabilities for future policy benefits and unpaid policy claims are not financial instruments as defined by U.S. GAAP. Fixed maturities, perpetual securities, and equity securities We determine the fair values of our fixed maturity securities, perpetual securities, and public and privately issued equity securities using the following approaches or techniques: price quotes and valuations from third party pricing vendors (including quoted market prices readily available from public exchange markets) and non-binding price quotes we obtain from outside brokers. A third party pricing vendor has developed valuation models to determine fair values of privately issued securities to reflect the impact of the persistent economic environment and the changing regulatory framework. These models are discounted cash flow (DCF) valuation models, but also use information from related markets, specifically the CDS market to estimate expected cash flows. These models take into consideration any unique characteristics of the securities and make various adjustments to arrive at an appropriate issuer-specific loss adjusted credit curve. This credit curve is then used with the relevant recovery rates to estimate expected cash flows and modeling of additional features, including illiquidity adjustments, if necessary, to price the security by discounting those loss adjusted cash flows. In cases where a credit curve cannot be developed from the specific security features, the valuation methodology takes into consideration other market observable inputs, including: 1) the most appropriate comparable security(ies) of the issuer; 2) issuer-specific CDS spreads; 3) bonds or CDS spreads of comparable issuers with similar characteristics such as rating, geography, or sector; or 4) bond indices that are comparative in rating, industry, maturity and region. The pricing data and market quotes we obtain from outside sources, including third party pricing services, are reviewed internally for reasonableness. If a fair value appears unreasonable, we will re-examine the inputs and assess the reasonableness of the pricing data with the vendor. Additionally, we may compare the inputs to relevant market indices and other performance measurements. The output of this analysis is presented to the Company's Valuation and Classifications Subcommittee, or VCS. Based on the analysis provided to the VCS, the valuation is confirmed or may be revised if there is evidence of a more appropriate estimate of fair value based on available market data. We have performed verification of the inputs and calculations in any valuation models to confirm that the valuations represent reasonable estimates of fair value. The fixed maturities classified as Level 3 consist of securities for which there are limited or no observable valuation inputs. For Level 3 securities that are investment grade, we estimate the fair value of these securities by obtaining non-binding broker quotes from a limited number of brokers. These brokers base their quotes on a combination of their knowledge of the current pricing environment and market conditions. We consider these inputs to be unobservable. For Level 3 investments that are below-investment-grade securities, we consider a variety of significant valuation inputs in the valuation process, including forward exchange rates, yen swap rates, dollar swap rates, interest rate volatilities, credit spread data on specific issuers, assumed default and default recovery rates, and certain probability assumptions. In obtaining these valuation inputs, we have determined that certain pricing assumptions and data used by our pricing sources are difficult to validate or corroborate by the market and/or appear to be internally developed rather than observed in or corroborated by the market. The use of these unobservable valuation inputs causes more subjectivity in the valuation process for these securities. For the periods presented, we have not adjusted the quotes or prices we obtain from the pricing services and brokers we use. The following tables present the pricing sources for the fair values of our fixed maturities, perpetual securities, and equity securities as of December 31. 2015 (In millions) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Significant Unobservable Inputs Total Securities available for sale, carried at fair value: Fixed maturities: Government and agencies: Third party pricing vendor $ 18,669 $ 607 $ 0 $ 19,276 Total government and agencies 18,669 607 0 19,276 Municipalities: Third party pricing vendor 0 1,208 0 1,208 Total municipalities 0 1,208 0 1,208 Mortgage- and asset-backed securities: Third party pricing vendor 0 362 0 362 Broker/other 0 0 220 220 Total mortgage- and asset-backed securities 0 362 220 582 Public utilities: Third party pricing vendor 0 7,479 0 7,479 Total public utilities 0 7,479 0 7,479 Sovereign and supranational: Third party pricing vendor 0 1,407 0 1,407 Total sovereign and supranational 0 1,407 0 1,407 Banks/financial institutions: Third party pricing vendor 0 5,993 0 5,993 Broker/other 0 0 26 26 Total banks/financial institutions 0 5,993 26 6,019 Other corporate: Third party pricing vendor 0 29,378 0 29,378 Total other corporate 0 29,378 0 29,378 Total fixed maturities 18,669 46,434 246 65,349 Perpetual securities: Banks/financial institutions: Third party pricing vendor 0 1,742 0 1,742 Total banks/financial institutions 0 1,742 0 1,742 Other corporate: Third party pricing vendor 0 205 0 205 Total other corporate 0 205 0 205 Total perpetual securities 0 1,947 0 1,947 Equity securities: Third party pricing vendor 489 6 0 495 Broker/other 0 0 3 3 Total equity securities 489 6 3 498 Total securities available for sale $ 19,158 $ 48,387 $ 249 $ 67,794 2015 (In millions) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Significant Unobservable Inputs Total Securities held to maturity, carried at amortized cost: Fixed maturities: Government and agencies: Third party pricing vendor $ 23,391 $ 0 $ 0 $ 23,391 Total government and agencies 23,391 0 0 23,391 Municipalities: Third party pricing vendor 0 415 0 415 Total municipalities 0 415 0 415 Mortgage- and asset-backed securities: Third party pricing vendor 0 12 0 12 Broker/other 0 0 26 26 Total mortgage- and asset-backed securities 0 12 26 38 Public utilities: Third party pricing vendor 0 3,203 0 3,203 Total public utilities 0 3,203 0 3,203 Sovereign and supranational: Third party pricing vendor 0 2,711 0 2,711 Total sovereign and supranational 0 2,711 0 2,711 Banks/financial institutions: Third party pricing vendor 0 4,546 0 4,546 Total banks/financial institutions 0 4,546 0 4,546 Other corporate: Third party pricing vendor 0 3,189 0 3,189 Broker/other 0 27 0 27 Total other corporate 0 3,216 0 3,216 Total securities held to maturity $ 23,391 $ 14,103 $ 26 $ 37,520 2014 (In millions) Quoted Prices in Active Markets Significant Observable Significant Unobservable Inputs Total Securities available for sale, carried at fair value: Fixed maturities: Government and agencies: Third party pricing vendor $ 18,683 $ 515 $ 0 $ 19,198 Total government and agencies 18,683 515 0 19,198 Municipalities: Third party pricing vendor 0 1,257 0 1,257 Total municipalities 0 1,257 0 1,257 Mortgage- and asset-backed securities: Third party pricing vendor 0 379 0 379 Broker/other 0 0 223 223 Total mortgage- and asset-backed securities 0 379 223 602 Public utilities: Third party pricing vendor 0 7,897 0 7,897 Total public utilities 0 7,897 0 7,897 Sovereign and supranational: Third party pricing vendor 0 1,416 0 1,416 Total sovereign and supranational 0 1,416 0 1,416 Banks/financial institutions: Third party pricing vendor 0 6,514 0 6,514 Broker/other 0 58 26 84 Total banks/financial institutions 0 6,572 26 6,598 Other corporate: Third party pricing vendor 0 28,605 0 28,605 Total other corporate 0 28,605 0 28,605 Total fixed maturities 18,683 46,641 249 65,573 Perpetual securities: Banks/financial institutions: Third party pricing vendor 0 2,289 0 2,289 Broker/other 0 0 149 149 Total banks/financial institutions 0 2,289 149 2,438 Other corporate: Third party pricing vendor 0 231 0 231 Total other corporate 0 231 0 231 Total perpetual securities 0 2,520 149 2,669 Equity securities: Third party pricing vendor 19 6 0 25 Broker/other 0 0 3 3 Total equity securities 19 6 3 28 Total securities available for sale $ 18,702 $ 49,167 $ 401 $ 68,270 2014 (In millions) Quoted Prices in Active Markets Significant Observable Significant Unobservable Inputs Total Securities held to maturity, carried at amortized cost: Fixed maturities: Government and agencies: Third party pricing vendor $ 23,218 $ 0 $ 0 $ 23,218 Total government and agencies 23,218 0 0 23,218 Municipalities: Third party pricing vendor 0 417 0 417 Total municipalities 0 417 0 417 Mortgage- and asset-backed securities: Third party pricing vendor 0 15 0 15 Broker/other 0 0 31 31 Total mortgage- and asset-backed securities 0 15 31 46 Public utilities: Third party pricing vendor 0 3,603 0 3,603 Total public utilities 0 3,603 0 3,603 Sovereign and supranational: Third party pricing vendor 0 2,814 0 2,814 Total sovereign and supranational 0 2,814 0 2,814 Banks/financial institutions: Third party pricing vendor 0 5,085 0 5,085 Total banks/financial institutions 0 5,085 0 5,085 Other corporate: Third party pricing vendor 0 3,287 0 3,287 Broker/other 0 27 0 27 Total other corporate 0 3,314 0 3,314 Total securities held to maturity $ 23,218 $ 15,248 $ 31 $ 38,497 The following is a discussion of the determination of fair value of our remaining financial instruments. Derivatives We use derivative instruments to manage the risk associated with certain assets. However, the derivative instrument may not be classified in the same fair value hierarchy level as the associated asset. Inputs used to value derivatives include, but are not limited to, interest rates, credit spreads, foreign currency forward and spot rates, and interest volatility. The fair values of the foreign currency forwards, options, and interest rate swaptions associated with certain fixed-maturity securities; the foreign currency forwards and options used to hedge foreign exchange risk from our net investment in Aflac Japan and economically hedge certain portions of forecasted cash flows denominated in yen; and the foreign currency swaps associated with certain senior notes and our subordinated debentures are based on the amounts we would expect to receive or pay. The determination of the fair value of these derivatives is based on observable market inputs, therefore they are classified as Level 2. For derivatives associated with VIEs where we are the primary beneficiary, we are not the direct counterparty to the swap contracts. As a result, the fair value measurements incorporate the credit risk of the collateral associated with the VIE. We receive valuations from a third party pricing vendor for these derivatives. Based on an analysis of these derivatives and a review of the methodology employed by the pricing vendor, we determined that due to the long duration of these swaps and the need to extrapolate from short-term observable data to derive and measure long-term inputs, certain inputs, assumptions and judgments are required to value future cash flows that cannot be corroborated by current inputs or current observable market data. As a result, the derivatives associated with our consolidated VIEs are classified as Level 3 of the fair value hierarchy. Other policyholders' funds The largest component of the other policyholders' funds liability is our annuity line of business in Aflac Japan. Our annuities have fixed benefits and premiums. For this product, we estimated the fair value to be equal to the cash surrender value. This is analogous to the value paid to policyholders on the valuation date if they were to surrender their policy. We periodically check the cash value against discounted cash flow projections for reasonableness. We consider our inputs for this valuation to be unobservable and have accordingly classified this valuation as Level 3. Notes payable The fair values of our publicly issued notes payable classified as Level 3 were obtained from a limited number of independent brokers. These brokers base their quotes on a combination of their knowledge of the current pricing environment and market conditions. We consider these inputs to be unobservable. The fair values of our yen-denominated loans approximate their carrying values. Hierarchy Levels and Level 3 Rollfoward There were no transfers between Level 1 and 2 for the years ended December 31, 2015 and 2014 , respectively. The following tables present the changes in fair value of our available-for-sale investments and derivatives classified as Level 3 as of December 31. 2015 Fixed Maturities Perpetual Equity Derivatives (1) (In millions) Mortgage- Public Sovereign Banks/ Other Banks/ Interest Foreign Credit Total Balance, beginning of period $ 223 $ 0 $ 0 $ 26 $ 0 $ 149 $ 3 $ 0 $ (212 ) $ 0 $ 189 Realized investment gains (losses) included 0 0 0 0 0 0 0 0 (15 ) 1 (14 ) Unrealized gains (losses) included in other (1 ) 0 0 0 0 (2 ) 0 0 (1 ) 0 (4 ) Purchases, issuances, sales and settlements: Purchases 0 0 0 0 0 0 0 0 0 0 0 Issuances 0 0 0 0 0 0 0 0 0 0 0 Sales 0 0 0 0 0 (147 ) 0 0 0 0 (147 ) Settlements (2 ) 0 0 0 0 0 0 0 36 0 34 Transfers into Level 3 0 0 0 0 0 0 0 0 0 0 0 Transfers out of Level 3 0 0 0 0 0 0 0 0 0 0 0 Balance, end of period $ 220 $ 0 $ 0 $ 26 $ 0 $ 0 $ 3 $ 0 $ (192 ) $ 1 $ 58 Changes in unrealized gains (losses) relating $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ (15 ) $ 1 $ (14 ) (1) Derivative assets and liabilities are presented net 2014 Fixed Maturities Perpetual Equity Derivatives (1) (In millions) Mortgage- Public Sovereign Banks/ Other Banks/ Interest Foreign Credit Total Balance, beginning of period $ 369 $ 0 $ 0 $ 23 $ 0 $ 52 $ 3 $ 1 $ (99 ) $ (3 ) $ 346 Realized investment gains (losses) included 0 0 0 0 0 0 0 (1 ) (191 ) 3 (189 ) Unrealized gains (losses) included in other (134 ) 0 0 3 0 8 0 0 (17 ) 0 (140 ) Purchases, issuances, sales and settlements: Purchases 0 0 0 0 0 0 0 0 0 0 0 Issuances 0 0 0 0 0 0 0 0 0 0 0 Sales 0 0 0 0 0 (60 ) 0 0 0 0 (60 ) Settlements (12 ) 0 0 0 0 0 0 0 95 0 83 Transfers into Level 3 (2) 0 0 0 0 0 149 0 0 0 0 149 Transfers out of Level 3 0 0 0 0 0 0 0 0 0 0 0 Balance, end of period $ 223 $ 0 $ 0 $ 26 $ 0 $ 149 $ 3 $ 0 $ (212 ) $ 0 $ 189 Changes in unrealized gains (losses) relating $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ (1 ) $ (191 ) $ 3 $ (189 ) (1) Derivative assets and liabilities are presented net (2) Due to use of estimated redemption price Level 3 Significant Unobservable Input Sensitivity The following tables summarize the significant unobservable inputs used in the valuation of our Level 3 available-for-sale investments and derivatives as of December 31. Included in the tables are the inputs or range of possible inputs that have an effect on the overall valuation of the financial instruments. 2015 (In millions) Fair Value Valuation Technique(s) Unobservable Input Range Assets: Securities available for sale, carried at fair value: Fixed maturities: Mortgage- and asset-backed securities $ 220 Consensus pricing Offered quotes N/A (d) Banks/financial institutions 26 Consensus pricing Offered quotes N/A (d) Equity securities 3 Net asset value Offered quotes $1 - $677 ($7) Other assets: Foreign currency swaps 7 Discounted cash flow Interest rates (USD) 2.20% - 2.62% (a) Interest rates (JPY) .42% - 1.22% (b) CDS spreads 32 - 147 bps Foreign exchange rates 20.05% (c) 94 Discounted cash flow Interest rates (USD) 2.20% - 2.62% (a) Interest rates (JPY) .42% - 1.22% (b) Foreign exchange rates 20.05% (c) Credit default swaps 1 Discounted cash flow Base correlation 53.26% - 58.40% (e) CDS spreads 123 bps Recovery rate 36.87% Total assets $ 351 (a) Inputs derived from U.S. long-term rates to accommodate long maturity nature of our swaps (b) Inputs derived from Japan long-term rates to accommodate long maturity nature of our swaps (c) Based on 10 year volatility of JPY/USD exchange rate (d) N/A represents securities where we receive unadjusted broker quotes and for which there is no transparency into the providers' valuation techniques or unobservable inputs. (e) Range of base correlation for our bespoke tranche for attachment and detachment points corresponding to market indices 2015 (In millions) Fair Value Valuation Technique(s) Unobservable Input Range Liabilities: Foreign currency swaps $ 158 Discounted cash flow Interest rates (USD) 2.20% - 2.62% (a) Interest rates (JPY) .42% - 1.22% (b) CDS spreads 32 - 147 bps Foreign exchange rates 20.05% (c) 120 Discounted cash flow Interest rates (USD) 2.20% - 2.62% (a) Interest rates (JPY) .42% - 1.22% (b) CDS spreads 35 - 213 bps 15 Discounted cash flow Interest rates (USD) 2.20% - 2.62% (a) Interest rates (JPY) .42% - 1.22% (b) Foreign exchange rates 20.05% (c) Total liabilities $ 293 (a) Inputs derived from U.S. long-term rates to accommodate long maturity nature of our swaps (b) Inputs derived from Japan long-term rates to accommodate long maturity nature of our swaps (c) Based on 10 year volatility of JPY/USD exchange rate 2014 (In millions) Fair Value Valuation Technique(s) Unobservable Input Range Assets: Securities available for sale, carried at fair value: Fixed maturities: Mortgage- and asset-backed securities $ 223 Consensus pricing Offered quotes N/A (d) Banks/financial institutions 26 Consensus pricing Offered quotes N/A (d) Perpetual securities: Banks/financial institutions 149 Consensus pricing Offered quotes N/A (d) Equity securities 3 Net asset value Offered quotes $1-$677 ($6) Other assets: Foreign currency swaps 8 Discounted cash flow Interest rates (USD) 2.28% - 2.70% (a) Interest rates (JPY) .53% - 1.34% (b) CDS spreads 16 - 105 bps Foreign exchange rates 20.50% (c) 98 Discounted cash flow Interest rates (USD) 2.28% - 2.70% (a) Interest rates (JPY) .53% - 1.34% (b) Foreign exchange rates 20.50% (c) Total assets $ 507 (a) Inputs derived from U.S. long-term rates to accommodate long maturity nature of our swaps (b) Inputs derived from Japan long-term rates to accommodate long maturity nature of our swaps (c) Based on 10 year volatility of JPY/USD exchange rate (d) N/A represents securities where we receive unadjusted broker quotes and for which there is no transparency into the providers' valuation techniques or unobservable inputs. 2014 (In millions) Fair Value Valuation Technique(s) Unobservable Input Range Liabilities: Foreign currency swaps $ 176 Discounted cash flow Interest rates (USD) 2.28% - 2.70% (a) Interest rates (JPY) .53% - 1.34% (b) CDS spreads 16 - 105 bps Foreign exchange rates 20.50% (c) 111 Discounted cash flow Interest rates (USD) 2.28% - 2.70% (a) Interest rates (JPY) .53% - 1.34% (b) CDS spreads 13 - 145 bps 31 Discounted cash flow Interest rates (USD) 2.28% - 2.70% (a) Interest rates (JPY) .53% - 1.34% (b) Foreign exchange rates 20.50% (c) Total liabilities $ 318 (a) Inputs derived from U.S. long-term rates to accommodate long maturity nature of our swaps (b) Inputs derived from Japan long-term rates to accommodate long maturity nature of our swaps (c) Based on 10 year volatility of JPY/USD exchange rate The following is a discussion of the significant unobservable inputs or valuation technique used in determining the fair value of securities and derivatives classified as Level 3. Net Asset Value We hold certain unlisted equity securities whose fair value is derived based on the financial statements published by the investee. These securities do not trade on an active market and the valuations derived are dependent on the availability of timely financial reporting of the investee. Net asset value is an unobservable input in the determination of fair value of equity securities. Offered Quotes In circumstances where our valuation model price is overridden because it implies a value that is not consistent with current market conditions, we will solicit bids from a limited number of brokers. We also receive unadjusted prices from brokers for our mortgage and asset-backed securities. These quotes are non-binding but are reflective of valuation best estimates at that particular point in time. Offered quotes are an unobservable input in the determination of fair value of mortgage- and asset-backed securities, certain banks/financial institutions, certain other corporate, and equity securities investments. Interest Rates, CDS Spreads, Foreign Exchange Rates The significant drivers of the valuation of the interest and foreign exchange swaps are interest rates, foreign exchange rates and CDS spreads. Our swaps have long maturities that increase the sensitivity of the swaps to interest rate fluctuations. Since most of our yen-denominated cross currency swaps are in a net liability position, an increase in interest rates will decrease the liabilities and increase the value of the swap. Foreign exchange swaps also have a lump-sum final settlement of foreign exchange principal receivables at the termination of the swap. An increase in yen interest rates will decrease the value of the final settlement foreign exchange receivables and decrease the value of the swap, and an increase in U.S. dollar interest rates increase the swap value. A similar sensitivity pattern is observed for the foreign exchange rates. When the spot U.S. dollar/Japanese yen (USD/JPY) foreign exchange rate decreases and the swap is receiving a final exchange payment in JPY, the swap value will increase due to the appreciation of the JPY. Most of our swaps are designed to receive payments in JPY at the termination and will thus be impacted by the USD/JPY foreign exchange rate in this way. In cases where there is no final foreign exchange receivable in JPY and we are paying JPY as interest payments and receiving USD, a decrease in the foreign exchange rate will lead to a decrease in the swap value. The extinguisher feature in most of our swaps results in a cessation of cash flows and no further payments between the parties to the swap in the event of a default on the referenced or underlying collateral. To price this feature, we apply the survival probability of the referenced entity to the projected cash flows. The survival probability uses the CDS spreads and recovery rates to adjust the present value of the cash flows. For extinguisher swaps with positive values, an increase in CDS spreads decreases the likelihood of receiving the final exchange payments and reduces the value of the swap. Due to the long duration of these swaps and the need to extrapolate from short-term observable data to derive and measure long-term inputs, certain inputs, assumptions and judgments are required to value future cash flows that cannot be corroborated by current inputs or current observable market data. Interest rates, CDS spreads, and foreign exchange rates are unobservable inputs in the determination of fair value of foreign currency swaps. Base Correlations, CDS Spreads, Recovery Rates Our remaining CDO is a tranche on a basket of single-name credit default swaps. The risk in this synthetic CDO comes from the single-name CDS risk and the correlations between the single names. The valuation of synthetic CDOs is dependent on the calibration of market prices for interest rates, single name CDS default probabilities and base correlation using financial modeling tools. Since there is limited or no observable data available for this tranche, the base correlations must be obtained from commonly traded market tranches such as the CDX and iTraxx indices. From the historical prices of these indices, base correlations can be obtained to develop a pricing curve of CDOs with different seniorities. Since the reference entities of the market indices do not match those in the portfolio underlying the synthetic CDO to be valued, several processing steps are taken to map the CDO in our portfolio to the indices. With the base correlation determined and the appropriate spreads selected, a valuation is calculated. An increase in the CDS spreads in the underlying portfolio leads to a decrease in the value due to higher probability of defaults and losses. The impact on the valuation due to base correlation depends on a number of factors, including the riskiness between market tranches and the modeled tranche based on our portfolio and the equivalence between detachment points in these tranches. Generally speaking, an increase in base correlation will decrease the value of the senior tranches while increasing the value of junior tranches. This may result in a positive or negative value change. The CDO tranche in our portfolio is a senior mezzanine tranche and, due to the low level of credit support for this type of tranche, exhibits equity-like behavior. As a result, an increase in recovery rates tends to cause its value to decrease. Base correlations, CDS spreads, and recovery rates are unobservable inputs in the determination of fair value of credit default swaps. For additional information on our investments and financial instruments, see the accompanying Notes 1, 3 and 4.

DEFERRED POLICY ACQUISITION COS

DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES	12 Months Ended
	Dec. 31, 2015
Deferred Policy Acquisition Costs Disclosures [Abstract]
DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES	DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES Consolidated policy acquisition costs deferred were $1.3 billion in 2015 and 2014 , compared with $1.4 billion in 2013 . The following table presents a rollforward of deferred policy acquisition costs by segment for the years ended December 31. 2015 2014 (In millions) Japan U.S. Japan U.S. Deferred policy acquisition costs: Balance, beginning of year $ 5,211 $ 3,062 $ 5,819 $ 2,979 Capitalization 738 578 790 548 Amortization (578 ) (488 ) (649 ) (459 ) Foreign currency translation and other (1 ) (11 ) (749 ) (6 ) Balance, end of year $ 5,370 $ 3,141 $ 5,211 $ 3,062 Commissions deferred as a percentage of total acquisition costs deferred were 74% in 2015 , compared with 77% in 2014 and 81% in 2013 . Personnel, compensation and benefit expenses as a percentage of insurance expenses were 52% in 2015 and 2014, compared with 51% in 2013 . Advertising expense, which is included in insurance expenses in the consolidated statements of earnings, was as follows for the years ended December 31: (In millions) 2015 2014 2013 Advertising expense: Aflac Japan $ 82 $ 103 $ 112 Aflac U.S. 129 126 128 Total advertising expense $ 211 $ 229 $ 240 Depreciation and other amortization expenses, which are included in insurance expenses in the consolidated statements of earnings, were as follows for the years ended December 31: (In millions) 2015 2014 2013 Depreciation expense $ 44 $ 47 $ 56 Other amortization expense 6 8 13 Total depreciation and other amortization expense $ 50 $ 55 $ 69 Lease and rental expense, which are included in insurance expenses in the consolidated statements of earnings, were as follows for the years ended December 31: (In millions) 2015 2014 2013 Lease and rental expense: Aflac Japan $ 46 $ 52 $ 55 Aflac U.S. 18 15 10 Other 1 1 1 Total lease and rental expense $ 65 $ 68 $ 66

POLICY LIABILITIES

POLICY LIABILITIES	12 Months Ended
	Dec. 31, 2015
Insurance Loss Reserves [Abstract]
POLICY LIABILITIES	POLICY LIABILITIES Policy liabilities consist of future policy benefits, unpaid policy claims, unearned premiums, and other policyholders' funds, which accounted for 80% , 4% , 9% and 7% of total policy liabilities at December 31, 2015 , respectively. We regularly review the adequacy of our policy liabilities in total and by component. The liability for future policy benefits as of December 31 consisted of the following: Liability Amounts Interest Rates (In millions) Policy 2015 2014 Year of In 20 Health insurance: Japan: 1992 - 2015 $ 7,633 $ 3,900 1.25 - 2.5 % 1.25 - 2.5 % 1974 - 2013 1,078 3,449 2.7 - 2.75 2.25 - 2.75 1998 - 2014 11,008 10,641 3.0 3.0 1997 - 1999 2,435 2,461 3.5 3.5 1994 - 1996 2,998 3,023 4.0 - 4.5 4.0 - 4.5 1987 - 1994 14,161 14,394 5.5 5.5 1985 - 1991 1,868 1,923 5.25 - 6.75 5.25 - 5.5 1978 - 1984 2,163 2,260 6.5 5.5 U.S.: 2013 - 2015 57 42 3.0 - 3.5 3.0 - 3.5 2012 - 2015 794 546 3.75 3.75 2011 300 276 4.75 4.75 2005 - 2010 2,986 2,951 5.5 5.5 1988 - 2004 687 706 8.0 6.0 1986 - 2004 1,276 1,293 6.0 6.0 1981 - 1986 174 183 6.5 - 7.0 5.5 - 6.5 1998 - 2004 1,279 1,260 7.0 7.0 Other 21 21 Intercompany eliminations: 2015 (646 ) (1) 0 2.0 2.0 Life insurance: Japan: 2001 - 2015 5,441 3,986 1.5 - 1.85 1.5 - 1.85 2011 - 2015 3,226 2,298 2.0 2.0 2009 - 2011 2,332 1,890 2.25 2.25 1992 - 2006 5 0 2.35 1.77 2005 - 2011 1,330 1,214 2.5 2.5 1985 - 2006 1,962 2,006 2.7 2.25 2007 - 2011 1,105 1,010 2.75 2.75 1999 - 2011 1,988 1,944 3.0 3.0 1996 - 2009 635 633 3.5 3.5 1994 - 1996 877 884 4.0 - 4.5 4.0 - 4.5 U.S.: 1956 - 2015 514 452 3.5 - 6.0 3.5 - 6.0 Total $ 69,687 $ 65,646 (1) Elimination entry necessary due to recapture of a portion of policy liabilities ceded externally, as a result of the reinsurance retrocession transaction as described in Note 8 of the Notes to the Consolidated Financial Statements The weighted-average interest rates reflected in the consolidated statements of earnings for future policy benefits for Japanese policies were 3.6% in 2015 , compared with 3.8% in 2014 and 3.9% in 2013 ; and for U.S. policies, 5.6% in 2015 , compared with 5.7% in 2014 and 5.8% in 2013 . Changes in the liability for unpaid policy claims were as follows for the years ended December 31: (In millions) 2015 2014 2013 Unpaid supplemental health claims, beginning of year $ 3,412 $ 3,537 $ 3,781 Less reinsurance recoverables 7 9 10 Net balance, beginning of year 3,405 3,528 3,771 Add claims incurred during the year related to: Current year 6,416 6,866 7,215 Prior years (353 ) (301 ) (236 ) Total incurred 6,063 6,565 6,979 Less claims paid during the year on claims incurred during: Current year 4,227 4,532 4,834 Prior years 1,718 1,873 1,931 Total paid 5,945 6,405 6,765 Effect of foreign exchange rate changes on unpaid claims (1 ) (283 ) (457 ) Net balance, end of year 3,522 3,405 3,528 Add reinsurance recoverables 26 7 9 Unpaid supplemental health claims, end of year 3,548 3,412 3,537 Unpaid life claims, end of year 254 218 226 Total liability for unpaid policy claims $ 3,802 $ 3,630 $ 3,763 The incurred claims development related to prior years reflects favorable claims experience compared to previous estimates, primarily in our lines of business in Japan. As of December 31, 2015 and 2014 , unearned premiums consisted primarily of discounted advance premiums on deposit. Discounted advance premiums are premiums on deposit from policyholders in conjunction with their purchase of certain Aflac Japan limited-pay insurance products. These advanced premiums are deferred upon collection and recognized as premium revenue over the contractual premium payment period. These advanced premiums represented 77% of the December 31, 2015 and 80% of the December 31, 2014 unearned premiums balances. As of December 31, 2015 and 2014 , the largest component of the other policyholders' funds liability is our annuity line of business in Aflac Japan. Our annuities have fixed benefits and premiums. These annuities represented 98% of the December 31, 2015 and 2014 other policyholders' funds liability.

REINSURANCE

REINSURANCE	12 Months Ended
	Dec. 31, 2015
Reinsurance Disclosures [Abstract]
REINSURANCE	REINSURANCE We enter into fixed quota-share coinsurance agreements with other companies in the normal course of business. For each of our reinsurance agreements, we determine whether the agreement provides indemnification against loss or liability relating to insurance risk in accordance with applicable accounting standards. Reinsurance premiums and benefits paid or provided are accounted for on bases consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Premiums and benefits are reported net of insurance ceded. Effective March 31, 2015, we entered into a coinsurance transaction whereby we ceded 30.0% of the sickness hospital benefit of one of Aflac Japan’s closed in-force blocks of business. In December 2015, we entered into an agreement for an $80 million letter of credit as collateral for this reinsurance transaction (see Note 13 for additional information). Effective April 1, 2015, we entered into a retrocession coinsurance transaction whereby we assumed 27.0% of the sickness hospital benefit of one of Aflac Japan’s closed in-force blocks of business through our subsidiary CAIC. Effective October 1, 2014 and September 30, 2013, we entered into coinsurance reinsurance transactions whereby we ceded 16.7% and 33.3% , respectively, of the hospital benefit of one of Aflac Japan’s closed medical in-force blocks of business. Effective December 31, 2014, we entered into a retrocession coinsurance reinsurance transaction whereby we assumed 8.35% of the reinsured hospital benefit of one of Aflac Japan’s closed medical in-force blocks of business through our subsidiary CAIC. For our reinsurance transactions to date, we have recorded a deferred profit liability related to the reinsurance transactions. The remaining deferred profit liability of $786 million , as of December 31, 2015 , included in future policy benefits in the consolidated balance sheet, is being amortized into income over the expected lives of the policies. We also have recorded a reinsurance recoverable for reinsurance transactions, which is included in other assets in the consolidated balance sheet and had a remaining balance of $805 million as of December 31, 2015 . The following table reconciles direct premium income and direct benefits and claims to net amounts after the effect of reinsurance for the years ended December 31. (In millions) 2015 2014 Direct premium income $ 17,904 $ 19,412 Ceded to other companies: Ceded Aflac Japan closed blocks (481 ) (311 ) Other (39 ) (39 ) Assumed from other companies: Retrocession activities 178 0 Other 8 10 Net premium income $ 17,570 $ 19,072 Direct benefits and claims $ 12,041 $ 13,235 Ceded benefits and change in reserves for future benefits: Ceded Aflac Japan closed blocks (437 ) (276 ) Other 16 (27 ) Assumed from other companies: Retrocession activities 167 0 Other (41 ) 5 Benefits and claims, net $ 11,746 $ 12,937 These reinsurance transactions are indemnity reinsurance that do not relieve us from our obligations to policyholders. In the event that the reinsurer is unable to meet their obligations, we remain liable for the reinsured claims. As a part of our capital contingency plan, we entered into a committed reinsurance facility agreement on December 1, 2015 in the amount of approximately 110 billion yen. This reinsurance facility agreement is effective from December 1, 2015 until December 31, 2016. There are also additional commitment periods of a one-year duration each which are automatically extended unless notification is received from the reinsurer within 60 days prior to the expiration. The reinsurer can withdraw from the committed facility if Aflac‘s Standard and Poor's (S&P) rating drops below BBB-. As of December 31, 2015, we have not executed a reinsurance treaty under this committed reinsurance facility.

NOTES PAYABLE

NOTES PAYABLE	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
NOTES PAYABLE	NOTES PAYABLE A summary of notes payable as of December 31 follows: (In millions) 2015 2014 3.45% senior notes paid August 2015 $ 0 $ 300 2.65% senior notes due February 2017 652 (1) 653 (1) 8.50% senior notes due May 2019 0 (2) 850 2.40% senior notes due March 2020 550 0 4.00% senior notes due February 2022 350 350 3.625% senior notes due June 2023 700 700 3.625% senior notes due November 2024 749 (3) 749 (3) 3.25% senior notes due March 2025 448 (3) 0 6.90% senior notes due December 2039 397 (3) 397 (3) 6.45% senior notes due August 2040 448 (3) 448 (3) 5.50% subordinated debentures due September 2052 500 500 Yen-denominated Uridashi notes: 2.26% notes due September 2016 (principal amount 8 billion yen) 66 66 Yen-denominated Samurai notes: 1.84% notes due July 2016 (principal amount 15.8 billion yen) 131 131 Yen-denominated loans: 3.60% loan paid July 2015 (principal amount 10 billion yen) 0 83 3.00% loan paid August 2015 (principal amount 5 billion yen) 0 41 Capitalized lease obligations payable through 2022 20 14 Total notes payable $ 5,011 $ 5,282 (1) Principal amount plus an issuance premium that is being amortized over the life of the notes (2) Redeemed in April 2015 (3) Principal amount net of an issuance discount that is being amortized over the life of the notes In March 2015, the Parent Company issued two series of senior notes totaling $1.0 billion through a U.S. public debt offering. The first series, which totaled $550 million , bears interest at a fixed rate of 2.40% per annum, payable semi-annually, and has a five -year maturity. The second series, which totaled $450 million , bears interest at a fixed rate of 3.25% per annum, payable semi-annually, and has a ten -year maturity. We have entered into cross-currency swaps that convert the U.S. dollar-denominated principal and interest on the senior notes into yen-denominated obligations which results in lower nominal net interest rates on the debt. By entering into these cross-currency swaps, we economically converted our $550 million liability into a 67.0 billion yen liability and reduced the interest rate on this debt from 2.40% in dollars to .24% in yen, and we economically converted our $450 million liability into a 55.0 billion yen liability and reduced the interest rate on this debt from 3.25% in dollars to .82% in yen. In April 2015, the Parent Company used the proceeds from the March 2015 issuance of its fixed-rate senior notes to redeem $850 million of our 8.50% fixed-rate senior notes due May 2019 and to pay a portion of the corresponding $230 million make-whole premium due to the investors of these notes. In November 2014, the Parent Company issued $750 million of senior notes through a U.S. public debt offering. The notes bear interest at a fixed rate of 3.625% per annum, payable semi-annually, and have a ten -year maturity. These notes are redeemable at our option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the treasury rate plus 20 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date. We entered into cross-currency interest rate swaps to reduce interest expense by converting the U.S. dollar-denominated principal and interest on the senior notes we issued into yen-denominated obligations. By entering into the swaps, we economically converted our $750 million liability into an 85.3 billion yen liability and reduced the interest rate on this debt from 3.625% in dollars to 1.00% in yen. In June 2013, the Parent Company issued $700 million of senior notes through a U.S. public debt offering. The notes bear interest at a fixed rate of 3.625% per annum, payable semi-annually, and have a ten -year maturity. These notes are redeemable at our option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the treasury rate plus 20 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date. We entered into cross-currency interest rate swaps to reduce interest expense by converting the U.S. dollar-denominated principal and interest on the senior notes we issued into yen-denominated obligations. By entering into these swaps, we economically converted our $700 million liability into a 69.8 billion yen liability and reduced the interest rate on this debt from 3.625% in dollars to 1.50% in yen. In September 2012, the Parent Company issued $450 million of subordinated debentures through a U.S. public debt offering. The debentures bear interest at a fixed rate of 5.50% per annum, payable quarterly, and have a 40 -year maturity. In five years, on or after September 26, 2017 , we may redeem the debentures, in whole or in part, at their principal amount plus accrued and unpaid interest to, but excluding, the date of redemption; provided that if the debentures are not redeemed in whole, at least $25 million aggregate principal amount of the debentures must remain outstanding after giving effect to such redemption. The debentures may only be redeemed prior to September 26, 2017 , in whole but not in part, upon the occurrence of certain tax events or certain rating agency events, as specified in the indenture governing the terms of the debentures. We entered into cross-currency interest rate swaps to convert the U.S. dollar-denominated principal and interest on the subordinated debentures we issued into yen-denominated obligations. By entering into these swaps, we economically converted our $450 million liability into a 35.3 billion yen liability and reduced the interest rate on this debt from 5.50% in dollars to 4.41% in yen. The swaps will expire after the initial five -year non-callable period for the debentures. In October 2012 , the underwriters exercised their option, pursuant to the underwriting agreement, to purchase an additional $50 million principal amount of the debentures discussed above. We entered into a cross-currency interest rate swap to economically convert this $50 million liability into a 3.9 billion yen liability and reduce the interest rate from 5.50% in dollars to 4.42% in yen. The swap will expire after the initial five -year non-callable period for the debentures. In February 2012, the Parent Company issued two series of senior notes totaling $750 million through a U.S. public debt offering. The first series, which totaled $400 million , bears interest at a fixed rate of 2.65% per annum, payable semiannually, and has a five -year maturity. The second series, which totaled $350 million , bears interest at a fixed rate of 4.00% per annum, payable semiannually, and has a ten -year maturity. These notes are redeemable at our option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the principal amount of the notes or (ii) the present value of the remaining scheduled payments of principal and interest to be redeemed, discounted to the redemption date, plus accrued and unpaid interest. We entered into cross-currency interest rate swaps to reduce interest expense by converting the U.S. dollar-denominated principal and interest on the senior notes we issued into yen-denominated obligations. By entering into these swaps, we economically converted our $400 million liability into a 30.9 billion yen liability and reduced the interest rate on this debt from 2.65% in dollars to 1.22% in yen. We also economically converted our $350 million liability into a 27.0 billion yen liability and reduced the interest rate on this debt from 4.00% in dollars to 2.07% in yen. In July 2012, the Parent Company issued $250 million of senior notes that are an addition to the original first series of senior notes issued in February 2012. These notes have a five -year maturity and a fixed rate of 2.65% per annum, payable semiannually. In July 2011, the Parent Company issued three series of Samurai notes totaling 50.0 billion yen through a public debt offering. The first series, which totaled 28.7 billion yen, and the third series, which totaled 5.5 billion yen, were redeemed in July 2014. The second series, which totaled 15.8 billion yen, bears interest at a fixed rate of 1.84% per annum, payable semiannually, and has a five -year maturity. These Samurai notes are not available to U.S. persons. In 2010 and 2009, we issued senior notes through U.S. public debt offerings; the details of these notes are as follows. In August 2010, we issued $450 million and $300 million of senior notes that have 30 -year and five -year maturities, respectively. In August 2015, we paid off the $300 million senior notes upon their maturity. In December 2009, we issued $400 million of senior notes that have a 30 -year maturity. In May 2009, we issued $850 million of senior notes that had a ten -year maturity, and subsequently redeemed these notes in April 2015 using proceeds from the March 2015 issuance of fixed-rate senior notes. These senior notes pay interest semiannually and are redeemable at our option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the principal amount of the notes or (ii) the present value of the remaining scheduled payments of principal and interest to be redeemed, discounted to the redemption date, plus accrued and unpaid interest. In September 2006, the Parent Company issued a tranche of Uridashi notes totaling 10 billion yen with a ten -year maturity. These Uridashi notes pay interest semiannually, may only be redeemed prior to maturity upon the occurrence of a tax event as specified in the respective bond agreement and are not available to U.S. persons. During 2009, we extinguished 2.0 billion yen (par value) of these Uridashi notes by buying the notes on the open market at a cost of 1.4 billion yen, yielding a gain of .6 billion yen. In August 2015, we paid off a 5.0 billion yen loan at its maturity date (a total of approximately $41 million using the exchange rate at the maturity date). In July 2015, we paid off a 10.0 billion yen loan at its maturity date (a total of approximately $81 million using the exchange rate at the maturity date). For our yen-denominated notes and loans, the principal amount as stated in dollar terms will fluctuate from period to period due to changes in the yen/dollar exchange rate. We have designated the majority of our yen-denominated notes payable as a nonderivative hedge of the foreign currency exposure of our investment in Aflac Japan. The aggregate contractual maturities of notes payable during each of the years after December 31, 2015 , are as follows: (In millions) Long-term Capitalized Total 2016 $ 197 $ 6 $ 203 2017 650 5 655 2018 0 4 4 2019 0 3 3 2020 550 1 551 Thereafter 3,600 1 3,601 Total $ 4,997 $ 20 $ 5,017 In October 2015, the Parent Company and Aflac jointly entered into a 364 days uncommitted bilateral line of credit that provides for borrowings in the amount of $100 million . Borrowings will bear interest at the rate quoted by the bank and agreed upon at the time of making such loan and will have a three-month maturity period. There are no related facility fees, upfront expenses or financial covenant requirements. Borrowings under this credit agreement may be used for general corporate purposes. Borrowings under the financing agreement will mature no later than three months after the last drawdown date of October 15, 2016. As of December 31, 2015 , we did not have any borrowings outstanding under our $100 million credit agreement. In September 2015, we amended and restated our 50.0 billion yen senior unsecured revolving credit facility agreement, due to expire in March 2018, pursuant to which the Parent Company and Aflac jointly entered into a new five -year senior unsecured revolving credit facility agreement with a syndicate of financial institutions that provides for borrowings of up to 55.0 billion yen or the equivalent of yen in U.S. dollars on a revolving basis. This credit agreement provides for borrowings in Japanese yen or the equivalent of Japanese yen in U.S. dollars on a revolving basis. Borrowings bear interest at a rate per annum equal to, at our option, either (a) a eurocurrency rate determined by reference to the London Interbank Offered Rate (LIBOR) for the interest period relevant to such borrowing adjusted for certain additional costs or (b) a base rate determined by reference to the highest of (1) the federal funds effective rate plus ½ of 1%, (2) the rate of interest for such day announced by Mizuho Bank, Ltd. as its prime rate and (3) the eurocurrency rate for an interest period of one month plus 1.00%, in each case plus an applicable margin. The applicable margin ranges between .79% and 1.275% for eurocurrency rate borrowings and 0.0% and .275% for base rate borrowings, depending on the Parent Company’s debt ratings as of the date of determination. In addition, the Parent Company and Aflac are required to pay a facility fee on the commitments ranging between .085% and .225% , also based on the Parent Company’s debt ratings as of the date of determination. Borrowings under the amended and restated credit facility may be used for general corporate purposes, including a capital contingency plan for the operations of the Parent Company and Aflac. The amended and restated credit facility requires compliance with certain financial covenants on a quarterly basis and will expire on the earlier of (a) September 18, 2020, or (b) the date the commitments are terminated pursuant to an event of default, as such term is defined in the credit agreement. As of December 31, 2015 , we did not have any borrowings outstanding under our 55.0 billion yen revolving credit agreement. In February 2015, the Parent Company and Aflac jointly entered into an uncommitted bilateral line of credit with a third party that provides for borrowings in the amount of $50 million . Borrowings will bear interest at the rate quoted by the bank and agreed upon at the time of making such loan and will have a three-month maturity period. There are no related facility fees, upfront expenses or financial covenant requirements. Borrowings under this credit agreement may be used for general corporate purposes. As of December 31, 2015 , we did not have any borrowings outstanding under our $50 million credit agreement. We were in compliance with all of the covenants of our notes payable and lines of credit at December 31, 2015 . No events of default or defaults occurred during 2015 and 2014 .

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The components of income tax expense (benefit) applicable to pretax earnings for the years ended December 31 were as follows: (In millions) Foreign U.S. Total 2015: Current $ 1,063 $ 225 $ 1,288 Deferred 42 (1 ) 41 Total income tax expense $ 1,105 $ 224 $ 1,329 2014: Current $ 995 $ 84 $ 1,079 Deferred 125 336 461 Total income tax expense $ 1,120 $ 420 $ 1,540 2013: Current $ 934 $ 302 $ 1,236 Deferred 299 123 422 Total income tax expense $ 1,233 $ 425 $ 1,658 Japan enacted an income tax rate reduction effective for fiscal years beginning after March 31, 2012. The rate was reduced to 33.3% effective April 1, 2012, and an additional reduction to 30.8% became effective January 1, 2015. Income tax expense in the accompanying statements of earnings varies from the amount computed by applying the expected U.S. tax rate of 35% to pretax earnings. The principal reasons for the differences and the related tax effects for the years ended December 31 were as follows: (In millions) 2015 2014 2013 Income taxes based on U.S. statutory rates $ 1,352 $ 1,572 $ 1,685 Utilization of foreign tax credit (27 ) (32 ) (37 ) Nondeductible expenses 3 5 6 Other, net 1 (5 ) 4 Income tax expense $ 1,329 $ 1,540 $ 1,658 Total income tax expense for the years ended December 31 was allocated as follows: (In millions) 2015 2014 2013 Statements of earnings $ 1,329 $ 1,540 $ 1,658 Other comprehensive income (loss): Unrealized foreign currency translation gains (losses) during period 16 (419 ) 253 Unrealized gains (losses) on investment securities: Unrealized holding gains (losses) on investment (931 ) 2,237 (904 ) Reclassification adjustment for realized (gains) losses 21 19 19 Unrealized gains (losses) on derivatives during period 0 (3 ) (4 ) Pension liability adjustment during period (7 ) (31 ) 55 Total income tax expense (benefit) related to items of (901 ) 1,803 (581 ) Additional paid-in capital (exercise of stock options) 4 (7 ) (8 ) Total income taxes $ 432 $ 3,336 $ 1,069 The tax effect on other comprehensive income (loss) shown in the table above included a deferred income tax expense of $614 million in 2013, related to certain U.S. dollar-denominated investments that Aflac Japan maintained on behalf of Aflac U.S. As discussed in Note 1, prior to October 1, 2013, there was no translation adjustment to record in pretax other comprehensive income for the portfolio when the yen/dollar exchange rate changed, however deferred tax expense or benefit associated with the foreign exchange translation gains or losses on these U.S. dollar-denominated investments is recognized in total income tax expense on other comprehensive income until the securities mature or are sold. Excluding the tax amounts for these U.S. dollar-denominated investments from total taxes on other comprehensive income would result in an effective income tax rate on pretax other comprehensive income (loss) of 31% in 2013. The income tax effects of the temporary differences that gave rise to deferred income tax assets and liabilities as of December 31 were as follows: (In millions) 2015 2014 Deferred income tax liabilities: Deferred policy acquisition costs $ 2,282 $ 2,209 Unrealized gains on investment securities 1,684 2,584 Premiums receivable 139 139 Policy benefit reserves 1,313 1,376 Depreciation 61 51 Other 0 20 Total deferred income tax liabilities 5,479 6,379 Deferred income tax assets: Other basis differences in investment securities 1,422 1,331 Unfunded retirement benefits 15 16 Other accrued expenses 7 4 Policy and contract claims 113 99 Foreign currency loss on Japan branch 208 327 Deferred compensation 181 226 Capital loss carryforwards 0 26 Other 95 0 Total deferred income tax assets 2,041 2,029 Net deferred income tax liability 3,438 4,350 Current income tax liability 902 943 Total income tax liability $ 4,340 $ 5,293 Under U.S. income tax rules, only 35% of non-life operating losses can be offset against life insurance taxable income each year . For current U.S. income tax purposes, there were non-life operating loss carryforwards of $1 million expiring in 2035, and no tax credit carryforwards available at December 31, 2015 . The Company did not have any capital loss carryforwards available to offset capital gains at December 31, 2015 . We file federal income tax returns in the United States and Japan as well as state or prefecture income tax returns in various jurisdictions in the two countries. U.S. federal income tax returns for years before 2011 are no longer subject to examination. In Japan, the National Tax Agency (NTA) has completed exams through tax year 2012. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows for the years ended December 31: (In millions) 2015 2014 Balance, beginning of year $ 309 $ 328 Additions for tax positions of prior years 0 2 Reductions for tax positions of prior years (45 ) (21 ) Balance, end of year $ 264 $ 309 Included in the balance of the liability for unrecognized tax benefits at December 31, 2015 , are $261 million of tax positions for which the ultimate deductibility is highly certain, but for which there is uncertainty about the timing of such deductibility, compared with $307 million at December 31, 2014 . Because of the impact of deferred tax accounting, other than interest and penalties, the disallowance of the shorter deductibility period would not affect the annual effective tax rate, but would accelerate the payment of cash to the taxing authority to an earlier period. The Company has accrued approximately $3 million as of December 31, 2015 , for permanent uncertainties, which if reversed would not have a material effect on the annual effective rate. The Company recognizes accrued interest and penalties related to unrecognized tax benefits in income tax expense. We recognized approximately $11 million in interest and penalties in 2015 , 2014 and 2013 . The Company has accrued approximately $22 million for the payment of interest and penalties as of December 31, 2015 , compared with $30 million a year ago. As of December 31, 2015 , there were no material uncertain tax positions for which the total amounts of unrecognized tax benefits will significantly increase or decrease within the next 12 months.

SHAREHOLDERS' EQUITY

SHAREHOLDERS' EQUITY	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
SHAREHOLDERS' EQUITY	SHAREHOLDERS' EQUITY The following table is a reconciliation of the number of shares of the Company's common stock for the years ended December 31. (In thousands of shares) 2015 2014 2013 Common stock - issued: Balance, beginning of period 668,132 667,046 665,239 Exercise of stock options and issuance of restricted shares 1,591 1,086 1,807 Balance, end of period 669,723 668,132 667,046 Treasury stock: Balance, beginning of period 225,687 207,633 197,453 Purchases of treasury stock: Open market 21,179 19,660 13,212 Other 247 157 222 Dispositions of treasury stock: Shares issued to AFL Stock Plan (1,209) (1,251) (1,365) Exercise of stock options (465) (391) (1,734) Other (96) (121) (155) Balance, end of period 245,343 225,687 207,633 Shares outstanding, end of period 424,380 442,445 459,413 Outstanding share-based awards are excluded from the calculation of weighted-average shares used in the computation of basic EPS. The following table presents the approximate number of share-based awards to purchase shares, on a weighted-average basis, that were considered to be anti-dilutive and were excluded from the calculation of diluted earnings per share at December 31: (In thousands) 2015 2014 2013 Anti-dilutive share-based awards 1,862 1,215 2,198 The weighted-average shares used in calculating earnings per share for the years ended December 31 were as follows: (In thousands of shares) 2015 2014 2013 Weighted-average outstanding shares used for calculating basic EPS 430,654 451,204 464,502 Dilutive effect of share-based awards 2,518 2,796 2,906 Weighted-average outstanding shares used for calculating diluted EPS 433,172 454,000 467,408 Share Repurchase Program: During 2015 , we purchased 21.2 million shares of our common stock in the open market, compared with 19.7 million shares in 2014 and 13.2 million shares in 2013 . In August 2015, our board of directors authorized the purchase of an additional 40.0 million shares of our common stock. As of December 31, 2015 , a remaining balance of 48.4 million shares of our common stock was available for purchase under share repurchase authorizations by our board of directors. Voting Rights:  In accordance with the Parent Company's articles of incorporation, shares of common stock are generally entitled to one vote per share until they have been held by the same beneficial owner for a continuous period of 48 months , at which time they become entitled to 10 votes per share. Reclassifications from Accumulated Other Comprehensive Income The table below is a reconciliation of accumulated other comprehensive income by component for the years ended December 31. Changes in Accumulated Other Comprehensive Income 2015 (In millions) Unrealized Foreign Unrealized Unrealized Pension Total Balance, beginning of period $ (2,541 ) $ 4,672 $ (26 ) $ (126 ) $ 1,979 Other comprehensive 345 (1,646 ) 0 (13 ) (1,314 ) Amounts reclassified from 0 (40 ) 0 0 (40 ) Net current-period other 345 (1,686 ) 0 (13 ) (1,354 ) Balance, end of period $ (2,196 ) $ 2,986 $ (26 ) $ (139 ) $ 625 All amounts in the table above are net of tax. 2014 (In millions) Unrealized Foreign Unrealized Unrealized Pension Liability Adjustment Total Balance, beginning of period $ (1,505 ) $ 1,035 $ (12 ) $ (81 ) $ (563 ) Other comprehensive (1,036 ) 3,672 (14 ) (44 ) 2,578 Amounts reclassified from 0 (35 ) 0 (1 ) (36 ) Net current-period other (1,036 ) 3,637 (14 ) (45 ) 2,542 Balance, end of period $ (2,541 ) $ 4,672 $ (26 ) $ (126 ) $ 1,979 All amounts in the table above are net of tax. 2013 (In millions) Unrealized Foreign Unrealized Unrealized Pension Liability Adjustment Total Balance, beginning of period $ 333 $ 2,570 $ (5 ) $ (183 ) $ 2,715 Other comprehensive (1,833 ) (1,499 ) (7 ) 92 (3,247 ) Amounts reclassified from (5 ) (36 ) 0 10 (31 ) Net current-period other (1,838 ) (1,535 ) (7 ) 102 (3,278 ) Balance, end of period $ (1,505 ) $ 1,035 $ (12 ) $ (81 ) $ (563 ) All amounts in the table above are net of tax. The table below summarizes the amounts reclassified from each component of accumulated other comprehensive income based on source for the years ended December 31. Reclassifications Out of Accumulated Other Comprehensive Income (In millions) 2015 Details about Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Unrealized gains (losses) on available-for-sale $ 214 Sales and redemptions (153 ) Other-than-temporary impairment 61 Total before tax (21 ) Tax (expense) or benefit (1) $ 40 Net of tax Amortization of defined benefit pension items: Actuarial gains (losses) $ (17 ) Acquisition and operating expenses (2) Prior service (cost) credit 17 Acquisition and operating expenses (2) 0 Tax (expense) or benefit (1) $ 0 Net of tax Total reclassifications for the period $ 40 Net of tax (1) Based on 35% tax rate (2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 14 for additional details). (In millions) 2014 Details about Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Unrealized gains (losses) on available-for-sale $ 57 Sales and redemptions (3 ) Other-than-temporary impairment 54 Total before tax (19 ) Tax (expense) or benefit (1) $ 35 Net of tax Amortization of defined benefit pension items: Actuarial gains (losses) $ (15 ) Acquisition and operating expenses (2) Prior service (cost) credit 17 Acquisition and operating expenses (2) (1 ) Tax (expense) or benefit (1) $ 1 Net of tax Total reclassifications for the period $ 36 Net of tax (1) Based on 35% tax rate (2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 14 for additional details). (In millions) 2013 Details about Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Unrealized foreign currency translation gains $ 7 Sales and redemptions (2 ) Tax (expense) or benefit (1) $ 5 Net of tax Unrealized gains (losses) on available-for-sale $ 255 Sales and redemptions (199 ) Other-than-temporary impairment 56 Total before tax (20 ) Tax (expense) or benefit (1) $ 36 Net of tax Amortization of defined benefit pension items: Actuarial gains (losses) $ (19 ) Acquisition and operating expenses (2) Prior service (cost) credit 4 Acquisition and operating expenses (2) 5 Tax (expense) or benefit (1) $ (10 ) Net of tax Total reclassifications for the period $ 31 Net of tax (1) Based on 35% tax rate (2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 14 for additional details).

SHARE-BASED COMPENSATION

SHARE-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
SHARE-BASED COMPENSATION	SHARE-BASED COMPENSATION As of December 31, 2015 , the Company has outstanding share-based awards under two long-term incentive compensation plans. The first plan, which expired in February 2007, is a stock option plan which allowed grants for incentive stock options (ISOs) to employees and non-qualifying stock options (NQSOs) to employees and non-employee directors. The options have a term of 10 years. The exercise price of options granted under this plan is equal to the fair market value of a share of the Company's common stock at the date of grant. Options granted before the plan's expiration date remain outstanding in accordance with their terms. The second long-term incentive compensation plan allows awards to Company employees for ISOs, NQSOs, restricted stock, restricted stock units, and stock appreciation rights. Non-employee directors are eligible for grants of NQSOs, restricted stock, and stock appreciation rights. The ISOs and NQSOs have a term of 10 years, and the share-based awards generally vest upon time-based conditions or time- and performance-based conditions. Time-based vesting generally occurs after three years. Performance-based vesting conditions generally include the attainment of goals related to Company financial performance. As of December 31, 2015 , approximately 10.1 million shares were available for future grants under this plan, and the only performance-based awards issued and outstanding were restricted stock awards. Share-based awards granted to U.S.-based grantees are settled with authorized but unissued Company stock, while those issued to Japan-based grantees are settled with treasury shares. The following table presents the impact of the expense recognized in connection with share-based awards for the periods ended December 31. (In millions, except for per-share amounts) 2015 2014 2013 Impact on earnings from continuing operations $ 39 $ 41 $ 37 Impact on earnings before income taxes 39 41 37 Impact on net earnings 27 28 25 Impact on net earnings per share: Basic $ .06 $ .06 $ .05 Diluted .06 .06 .05 We estimate the fair value of each stock option granted using the Black-Scholes-Merton multiple option approach. Expected volatility is based on historical periods generally commensurate with the estimated terms of the options. We use historical data to estimate option exercise and termination patterns within the model. Separate groups of employees that have similar historical exercise patterns are stratified and considered separately for valuation purposes. The expected term of options granted is derived from the output of our option model and represents the weighted-average period of time that options granted are expected to be outstanding. We base the risk-free interest rate on the Treasury note rate with a term comparable to that of the estimated term of the options. The weighted-average fair value of options at their grant date was $9.46 per share for 2015 , compared with $16.24 for 2014 and $14.25 in 2013 . The following table presents the assumptions used in valuing options granted during the years ended December 31. 2015 2014 2013 Expected term (years) 6.3 6.3 6.6 Expected volatility 20.0 % 30.0 % 34.0 % Annual forfeiture rate 2.8 2.7 1.6 Risk-free interest rate 2.0 2.8 1.8 Dividend yield 2.7 2.3 2.6 The following table summarizes stock option activity. (In thousands of shares) Stock Weighted-Average Outstanding at December 31, 2012 12,737 $ 45.00 Granted in 2013 703 52.86 Canceled in 2013 (179 ) 44.79 Exercised in 2013 (3,281 ) 40.52 Outstanding at December 31, 2013 9,980 47.03 Granted in 2014 678 61.81 Canceled in 2014 (115 ) 52.01 Exercised in 2014 (1,236 ) 41.04 Outstanding at December 31, 2014 9,307 48.84 Granted in 2015 855 61.47 Canceled in 2015 (231 ) 55.70 Exercised in 2015 (2,013 ) 45.15 Outstanding at December 31, 2015 7,918 $ 50.94 (In thousands of shares) 2015 2014 2013 Shares exercisable, end of year 6,085 7,497 8,042 The following table summarizes information about stock options outstanding and exercisable at December 31, 2015 . (In thousands of shares) Options Outstanding Options Exercisable Range of Stock Option Wgtd.-Avg. Wgtd.-Avg. Stock Option Wgtd.-Avg. $ 14.99 - $ 43.07 1,651 3.1 $ 34.41 1,651 $ 34.41 43.28 - 48.56 1,727 3.2 47.05 1,723 47.05 49.50 - 57.90 2,066 4.9 54.18 1,608 55.01 58.08 - 61.81 1,628 5.1 61.50 956 61.79 61.84 - 67.67 846 7.8 62.96 147 63.96 $ 14.99 - $ 67.67 7,918 4.5 $ 50.94 6,085 $ 48.45 The aggregate intrinsic value represents the difference between the exercise price of the stock options and the quoted closing common stock price of $59.90 as of December 31, 2015 , for those awards that have an exercise price currently below the closing price. As of December 31, 2015 , the aggregate intrinsic value of stock options outstanding was $76 million , with a weighted-average remaining term of 4.5 years. The aggregate intrinsic value of stock options exercisable at that same date was $72 million , with a weighted-average remaining term of 3.3 years. The following table summarizes stock option activity during the years ended December 31. (In millions) 2015 2014 2013 Total intrinsic value of options exercised $ 36 $ 25 $ 66 Cash received from options exercised 68 39 113 Tax benefit realized as a result of options exercised and 25 17 30 The value of restricted stock awards is based on the fair market value of our common stock at the date of grant. The following table summarizes restricted stock activity during the years ended December 31. (In thousands of shares) Shares Weighted-Average Restricted stock at December 31, 2012 1,363 $ 50.19 Granted in 2013 782 52.77 Canceled in 2013 (56 ) 48.63 Vested in 2013 (418 ) 47.49 Restricted stock at December 31, 2013 1,671 52.12 Granted in 2014 584 62.12 Canceled in 2014 (27 ) 52.66 Vested in 2014 (348 ) 56.95 Restricted stock at December 31, 2014 1,880 54.33 Granted in 2015 638 61.51 Canceled in 2015 (145 ) 57.52 Vested in 2015 (558 ) 48.41 Restricted stock at December 31, 2015 1,815 $ 58.42 As of December 31, 2015 , total compensation cost not yet recognized in our financial statements related to restricted stock awards was $44 million , of which $20 million ( 849 thousand shares) was related to restricted stock awards with a performance-based vesting condition. We expect to recognize these amounts over a weighted-average period of approximately 1.1 years. There are no other contractual terms covering restricted stock awards once vested.

STATUTORY ACCOUNTING AND DIVIDE

STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS	12 Months Ended
	Dec. 31, 2015
Insurance [Abstract]
STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS	STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS Our insurance subsidiaries are required to report their results of operations and financial position to state insurance regulatory authorities on the basis of statutory accounting practices prescribed or permitted by such authorities. Statutory accounting practices primarily differ from U.S. GAAP by charging policy acquisition costs to expense as incurred, establishing future policy benefit liabilities using different actuarial assumptions as well as valuing investments and certain assets and accounting for deferred taxes on a different basis. Aflac, the Company's most significant insurance subsidiary, reports statutory financial statements that are prepared on the basis of accounting practices prescribed or permitted by the Nebraska Department of Insurance (NEDOI). The NEDOI recognizes statutory accounting principles and practices prescribed or permitted by the state of Nebraska for determining and reporting the financial condition and results of operations of an insurance company, and for determining a company's solvency under Nebraska insurance law. The National Association of Insurance Commissioners' (NAIC) Accounting Practices and Procedures Manual (SAP) has been adopted by the state of Nebraska as a component of those prescribed or permitted practices. Additionally, the Director of the NEDOI has the right to permit other specific practices which deviate from prescribed practices. Aflac has been given explicit permission by the Director of the NEDOI for two such permitted practices. These permitted practices, which do not impact the calculation of net income on a statutory basis or prevent the triggering of a regulatory event in the Company's risk-based capital calculation, are as follows: • Aflac has reported as admitted assets the refundable lease deposits on the leases of commercial office space which house Aflac Japan's sales operations. These lease deposits are unique and part of the ordinary course of doing business in the country of Japan; these assets would be non-admitted under SAP. • Aflac entered into a reinsurance agreement effective March 31, 2015 with a then unauthorized reinsurer. The effective date of this agreement predated the effective date of Nebraska's Amended Credit for Reinsurance statute (44-416) allowing certified reinsurers and also predated the subsequent approval of the agreement's assuming reinsurer as a Certified Reinsurer, which occurred on August 30, 2015 and December 24, 2015, respectively. Aflac has obtained a permitted practice to recognize this treaty and counterparty as Certified Reinsurer for the purpose of determining the collateral required to receive reinsurance reserve credit. A reconciliation of Aflac's capital and surplus between SAP and practices permitted by the state of Nebraska is shown below: (In millions) 2015 2014 Capital and surplus, Nebraska state basis $ 11,298 $ 10,839 State Permitted Practice: Refundable lease deposits – Japan (38 ) (36 ) Reinsurance - Japan (707 ) 0 Capital and surplus, NAIC basis $ 10,553 $ 10,803 As of December 31, 2015 , Aflac's capital and surplus significantly exceeded the required company action level capital and surplus of $1.3 billion . As determined on a U.S. statutory accounting basis, Aflac's net income was $2.3 billion in 2015 and $2.4 billion in 2014 and 2013 . Aflac Japan must report its results of operations and financial position to the Japanese Financial Services Agency (FSA) on a Japanese regulatory accounting basis as prescribed by the FSA. Capital and surplus of the Japan branch, based on Japanese regulatory accounting practices, was $4.7 billion at December 31, 2015 , compared with $5.6 billion at December 31, 2014 . Japanese regulatory accounting practices differ in many respects from U.S. GAAP. Under Japanese regulatory accounting practices, policy acquisition costs are expensed immediately; policy benefit and claim reserving methods and assumptions are different; premium income is recognized on a cash basis; different consolidation criteria apply to VIEs; reinsurance is recognized on a different basis; and investments can have a separate accounting classification and treatment referred to as policy reserve matching bonds (PRM). The Parent Company depends on its subsidiaries for cash flow, primarily in the form of dividends and management fees. Consolidated retained earnings in the accompanying financial statements largely represent the undistributed earnings of our insurance subsidiary. Amounts available for dividends, management fees and other payments to the Parent Company by its insurance subsidiary may fluctuate due to different accounting methods required by regulatory authorities. These payments are also subject to various regulatory restrictions and approvals related to safeguarding the interests of insurance policyholders. Our insurance subsidiary must maintain adequate risk-based capital for U.S. regulatory authorities and our Japan branch must maintain adequate solvency margins for Japanese regulatory authorities. Additionally, the maximum amount of dividends that can be paid to the Parent Company by Aflac without prior approval of Nebraska's director of insurance is the greater of the net income from operations, which excludes net realized investment gains, for the previous year determined under statutory accounting principles, or 10% of statutory capital and surplus as of the previous year-end. Dividends declared by Aflac during 2016 in excess of $2.3 billion would require such approval. Aflac declared dividends of $2.4 billion during 2015 . A portion of Aflac Japan earnings, as determined on a Japanese regulatory accounting basis, can be repatriated each year to Aflac U.S. after complying with solvency margin provisions and satisfying various conditions imposed by Japanese regulatory authorities for protecting policyholders. Profit repatriations to the United States can fluctuate due to changes in the amounts of Japanese regulatory earnings. Among other items, factors affecting regulatory earnings include Japanese regulatory accounting practices and fluctuations in currency translation of Aflac Japan's U.S. dollar-denominated investments and related investment income into yen. Profits repatriated by Aflac Japan to Aflac U.S. were as follows for the years ended December 31: In Dollars In Yen (In millions of dollars and billions of yen) 2015 2014 2013 2015 2014 2013 Profit repatriation $ 2,139 $ 1,704 $ 771 259.0 181.4 76.8 We entered into foreign exchange forwards and options as part of an economic hedge on foreign exchange risk on 242.5 billion yen of profit repatriation received in 2015, resulting in $71 million of additional funds received when the yen were exchanged into dollars. As of December 31, 2015 , we had foreign exchange forwards and options as part of a hedging strategy on 124.1 billion yen of future profit repatriation.

BENEFIT PLANS

BENEFIT PLANS	12 Months Ended
	Dec. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
BENEFIT PLANS	BENEFIT PLANS Pension and Other Postretirement Plans We have funded defined benefit plans in Japan and the United States, which cover substantially all of our full-time employees. Additionally, we maintain non-qualified, unfunded supplemental retirement plans that provide defined pension benefits in excess of limits imposed by federal tax law for certain Japanese, U.S. and former employees. Effective October 1, 2013, the U.S. tax-qualified defined benefit plan was frozen to new employees hired on or after October 1, 2013 and to employees rehired on or after October 1, 2013. U.S. employees who are not participants in the defined benefit plan receive a nonelective 401(k) employer contribution. Additionally, effective January 1, 2015, the U.S. non-qualified supplemental retirement plan was frozen to new participants. We provide certain health care benefits for eligible U.S. retired employees, their beneficiaries and covered dependents ("other postretirement benefits"). The health care plan is contributory and unfunded. On October 1, 2013, a change was made to postretirement medical benefits to limit the eligibility for the benefits beginning January 1, 2014 to include the following: (1) active employees whose age plus service, in years, equals or exceeds 80 (rule of 80 ); (2) active employees who are age 55 or older and have met the 15 years of service requirement; (3) active employees who will meet the rule of 80 in the next five years ; (4) active employees who are age 55 or older and who will meet the 15 years of service requirement within the next five years ; and (5) current retirees. Effective October 1, 2013, this change was accounted for as a negative plan amendment and resulted in a reduction to the postretirement benefit obligation of approximately $51 million , with an offset to accumulated other comprehensive income (AOCI). Starting in the fourth quarter of 2013, this reduction is being amortized as a reduction to net periodic benefit cost over three years . The postretirement plan obligation was remeasured using a discount rate of 4.75% as of October 1, 2013. For certain employees and former employees, additional coverage is provided for all medical expenses for life. Information with respect to our benefit plans' assets and obligations as of December 31 was as follows: Pension Benefits Other Japan U.S. Postretirement Benefits (In millions) 2015 2014 2015 2014 2015 2014 Projected benefit obligation: Benefit obligation, beginning of year $ 267 $ 270 $ 717 $ 601 $ 44 $ 46 Service cost 15 15 23 20 1 1 Interest cost 1 9 18 38 2 2 Actuarial (gain) loss 0 21 (6 ) 74 (5 ) (3 ) Benefits and expenses paid (7 ) (9 ) (17 ) (16 ) (2 ) (2 ) Effect of foreign exchange 0 (39 ) 0 0 0 0 Benefit obligation, end of year 276 267 735 717 40 44 Plan assets: Fair value of plan assets, 183 182 341 313 0 0 Actual return on plan assets 1 12 (6 ) 26 0 0 Employer contributions 21 24 18 18 2 2 Benefits and expenses paid (7 ) (9 ) (17 ) (16 ) (2 ) (2 ) Effect of foreign exchange 0 (26 ) 0 0 0 0 Fair value of plan assets, end of year 198 183 336 341 0 0 Funded status of the plans (1) $ (78 ) $ (84 ) $ (399 ) $ (376 ) $ (40 ) $ (44 ) Amounts recognized in accumulated other Net actuarial (gain) loss $ 42 $ 40 $ 175 $ 167 $ 12 $ 19 Prior service (credit) cost (2 ) (2 ) (4 ) (4 ) (11 ) (28 ) Total included in accumulated $ 40 $ 38 $ 171 $ 163 $ 1 $ (9 ) Accumulated benefit obligation $ 244 $ 235 $ 621 $ 611 N/A (2) N/A (2) (1) Recognized in other liabilities in the consolidated balance sheets (2) Not applicable Pension Benefits Other Japan U.S. Postretirement Benefits 2015 2014 2013 2015 2014 2013 2015 2014 2013 Weighted-average actuarial assumptions: Discount rate - net periodic benefit cost 1.75 % 2.25 % 2.25 % 4.50 % 4.75 % 4.25 % 4.50 % 4.75 % 4.25 % Discount rate - benefit obligations 1.75 1.75 2.25 4.50 4.50 4.75 4.50 4.50 4.75 Expected long-term return on plan assets 2.00 2.00 2.00 7.25 7.50 7.50 N/A (1) N/A (1) N/A (1) Rate of compensation increase N/A (1) N/A (1) N/A (1) 4.00 4.00 4.00 N/A (1) N/A (1) N/A (1) Health care cost trend rates N/A (1) N/A (1) N/A (1) N/A (1) N/A (1) N/A (1) 5.30 (2) 5.70 (2) 6.40 (2) (1) Not applicable (2) For the years 2015 , 2014 and 2013 , the health care cost trend rates are expected to trend down to 4.5% in 78 years , 4.6% in 78 years , and 4.6% in 78 years , respectively. We determine our discount rate assumption for our pension retirement obligations based on indices for AA corporate bonds with an average duration of approximately 20 years for the Japan pension plans and 17 years for the U.S. pension plans, and determination of the U.S. pension plans discount rate utilizes the 85 -year extrapolated yield curve. In Japan, participant salary and future salary increases are not factors in determining pension benefit cost or the related pension benefit obligation. We base our assumption for the long-term rate of return on assets on historical trends ( 10 -year or longer historical rates of return for the Japanese plan assets and 15 -year historical rates of return for the U.S. plan assets), expected future market movement, as well as the portfolio mix of securities in the asset portfolio including, but not limited to, style, class and equity and fixed income allocations. In addition, our consulting actuaries evaluate our assumptions for long-term rates of return under Actuarial Standards of Practice (ASOP). Under the ASOP, the actual portfolio type, mix and class is modeled to determine a best estimate of the long-term rate of return. We in turn use those results to further validate our own assumptions. Assumed health care cost trend rates have a significant effect on the amounts reported for the health care plan. A one-percentage point increase and decrease in assumed health care cost trend rates would have the following effects as of December 31, 2015 : (In millions) One percentage point increase: Increase in total service and interest costs $ 0 Increase in postretirement benefit obligation 2 One percentage point decrease: Decrease in total service and interest costs $ 0 Decrease in postretirement benefit obligation 2 Components of Net Periodic Benefit Cost Pension and other postretirement benefit expenses, included in acquisition and operating expenses in the consolidated statements of earnings for the years ended December 31, included the following components: Pension Benefits Other Japan U.S. Postretirement Benefits (In millions) 2015 2014 2013 2015 2014 2013 2015 2014 2013 Service cost $ 15 $ 15 $ 16 $ 23 $ 20 $ 22 $ 1 $ 1 $ 5 Interest cost 1 9 10 18 38 23 2 2 3 Expected return on plan (4 ) (4 ) (3 ) (22 ) (20 ) (17 ) 0 0 0 Amortization of net actuarial 1 1 2 14 11 15 2 3 2 Amortization of prior service 0 0 0 0 0 0 (17 ) (17 ) (4 ) Net periodic (benefit) cost $ 13 $ 21 $ 25 $ 33 $ 49 $ 43 $ (12 ) $ (11 ) $ 6 Changes in Accumulated Other Comprehensive Income The following table summarizes the amounts recognized in other comprehensive loss (income) for the years ended December 31: Pension Benefits Other Japan U.S. Postretirement Benefits (In millions) 2015 2014 2013 2015 2014 2013 2015 2014 2013 Net actuarial loss (gain) $ 3 $ 12 $ (14 ) $ 22 $ 67 $ (59 ) $ (5 ) $ (3 ) $ (7 ) Amortization of net actuarial loss (1 ) (1 ) (2 ) (14 ) (11 ) (15 ) (2 ) (3 ) (2 ) Prior service cost (credit) 0 0 0 0 0 (4 ) 0 0 (51 ) Amortization of prior 0 0 0 0 0 0 17 17 4 Total $ 2 $ 11 $ (16 ) $ 8 $ 56 $ (78 ) $ 10 $ 11 $ (56 ) Prior service credits of $51 million were incurred in 2013 for the plan amendment related to the change in eligibility for postretirement medical benefits mentioned above. No transition obligations arose during 2015 , and the transition obligations amortized to expense were immaterial for the years ended December 31, 2015 , 2014 and 2013 . Amortization of actuarial losses to expense in 2016 is estimated to be $1 million for the Japanese plans, $13 million for the U.S. plans and $1 million for the other postretirement benefits plan. Amortization of prior service credits in 2016 is estimated to be $10 million for the other postretirement benefits plan due to the negative plan amendment in 2013. The amortization of prior service costs and credits for other plans and transition obligations for all plans is expected to be negligible in 2016 . Benefit Payments The following table provides expected benefit payments, which reflect expected future service, as appropriate. Pension Benefits Other (In millions) Japan U.S. Postretirement Benefits 2016 $ 12 $ 21 $ 2 2017 7 22 3 2018 7 23 3 2019 9 24 3 2020 10 25 4 2021-2025 66 170 19 Funding We plan to make contributions of $20 million to the Japanese funded defined benefit plan and $10 million to the U.S. funded defined benefit plan in 2016 . The funding policy for our non-qualified supplemental defined benefit pension plans and other postretirement benefits plan is to contribute the amount of the benefit payments made during the year. Plan Assets The investment objective of our Japanese and U.S. funded defined benefit plans is to preserve the purchasing power of the plan's assets and earn a reasonable inflation-adjusted rate of return over the long term. Furthermore, we seek to accomplish these objectives in a manner that allows for the adequate funding of plan benefits and expenses. In order to achieve these objectives, our goal is to maintain a conservative, well-diversified and balanced portfolio of high-quality equity, fixed-income and money market securities. As a part of our strategy, we have established strict policies covering quality, type and concentration of investment securities. For our Japanese plan, these policies include limitations on investments in derivatives including futures, options and swaps, and low-liquidity investments such as real estate, venture capital investments, and privately issued securities. For our U.S. plan, these policies prohibit investments in precious metals, limited partnerships, venture capital, and direct investments in real estate. We are also prohibited from trading on margin. The plan fiduciaries for our funded defined benefit plans have developed guidelines for asset allocations reflecting a percentage of total assets by asset class, which are reviewed on an annual basis. Asset allocation targets as of December 31, 2015 were as follows: Japan Pension U.S. Pension Domestic equities 11 % 43 % International equities 15 22 Fixed income securities 59 35 Other 15 0 Total 100 % 100 % The following table presents the fair value of Aflac Japan's pension plan assets that are measured at fair value on a recurring basis as of December 31. All of these assets are classified as Level 2 in the fair value hierarchy, except cash and cash equivalents which are classified as Level 1. (In millions) 2015 2014 Japan pension plan assets: Equities: Japanese equity securities $ 22 $ 0 International equity securities 33 34 Fixed income securities: Japanese bonds 71 72 International bonds 48 44 Insurance contracts 23 22 Cash and cash equivalents 1 11 Total $ 198 $ 183 The following table presents the fair value of Aflac U.S.'s pension plan assets that are measured at fair value on a recurring basis as of December 31. All of these assets are classified as Level 1 in the fair value hierarchy. (In millions) 2015 2014 U.S. pension plan assets: Mutual funds: Large cap equity funds $ 94 $ 116 Mid cap equity funds 16 14 Real estate equity funds 10 10 International equity funds 77 61 Fixed income bond funds 134 136 Aflac Incorporated common stock 4 4 Cash and cash equivalents 1 0 Total $ 336 $ 341 The fair values of our pension plan investments categorized as Level 1, consisting of mutual funds and common stock, are based on quoted market prices for identical securities traded in active markets that are readily and regularly available to us. The fair values of our pension plan investments classified as Level 2 are based on quoted prices for similar assets in markets that are not active, other inputs that are observable, such as interest rates, yield curves, volatilities, prepayment speeds, loss severities, credit risks, and default rates, or other market-corroborated inputs. 401(k) Plan The Company sponsors a 401(k) plan in which we match a portion of U.S. employees' contributions. The plan provides for salary reduction contributions by employees and, in 2015 , 2014 , and 2013 , provided matching contributions by the Company of 50% of each employee's contributions which were not in excess of 6% of the employee's annual cash compensation. On January 1, 2014, the Company began providing a nonelective contribution to the 401(k) plan of 2% of annual cash compensation for employees who elected to opt out of the future benefits of the U.S. defined benefit plan during the election period provided during the fourth quarter of 2013 and for new U.S. employees who started working for the Company after September 30, 2013. The 401(k) contributions by the Company, included in acquisition and operating expenses in the consolidated statements of earnings, were $9 million in 2015 , $7 million in 2014 and $5 million in 2013 . The plan trustee held approximately one million shares of our common stock for plan participants at December 31, 2015 . Stock Bonus Plan Aflac U.S. maintains a stock bonus plan for eligible U.S. sales associates. Plan participants receive shares of Aflac Incorporated common stock based on their new annualized premium sales and their first-year persistency of substantially all new insurance policies. The cost of this plan, which was capitalized as deferred policy acquisition costs, amounted to $34 million in 2015 , compared with $36 million in 2014 and $38 million in 2013 .

COMMITMENTS AND CONTINGENT LIAB

COMMITMENTS AND CONTINGENT LIABILITIES	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENT LIABILITIES	COMMITMENTS AND CONTINGENT LIABILITIES We have two outsourcing agreements with a technology and consulting corporation. The first agreement provides mainframe computer operations, distributed mid-range server computer operations, and related support for Aflac Japan. It has a remaining term of five years and an aggregate remaining cost of 36.0 billion yen ( $298 million using the December 31, 2015 , exchange rate). The second agreement provides application maintenance and development services for Aflac Japan. It has a remaining term of two years and an aggregate remaining cost of 2.4 billion yen ( $20 million using the December 31, 2015 , exchange rate). We have an outsourcing agreement with a management consulting and technology services company to provide application maintenance and development services for our Japanese operation. The agreement has a remaining term of two years with an aggregate remaining cost of 3.1 billion yen ( $26 million using the December 31, 2015 , exchange rate). We have two outsourcing agreements with information technology and data services companies to provide application maintenance and development services for our Japanese operation. The first agreement has a remaining term of one year with an aggregate remaining cost of 637 million yen ( $5 million using the December 31, 2015 , exchange rate). The second agreement has a remaining term of two years with an aggregate remaining cost of 1.6 billion yen ( $13 million using the December 31, 2015 , exchange rate). As of December 31, 2015 , we have commitments of $182 million to fund potential future loan originations related to our investment in middle market loans. These commitments are contingent upon the availability of middle market loans that meet our underwriting criteria. See Note 3 of the Notes to the Consolidated Financial Statements for more details on this investment program. We lease office space and equipment under agreements that expire in various years through 2026 . Future minimum lease payments due under non-cancelable operating leases at December 31, 2015 , were as follows: (In millions) 2016 $ 59 2017 44 2018 31 2019 10 2020 8 Thereafter 20 Total future minimum lease payments $ 172 We are a defendant in various lawsuits considered to be in the normal course of business. Members of our senior legal and financial management teams review litigation on a quarterly and annual basis. The final results of any litigation cannot be predicted with certainty. Although some of this litigation is pending in states where large punitive damages, bearing little relation to the actual damages sustained by plaintiffs, have been awarded in recent years, we believe the outcome of pending litigation will not have a material adverse effect on our financial position, results of operations, or cash flows.

UNAUDITED CONSOLIDATED QUARTERL

UNAUDITED CONSOLIDATED QUARTERLY FINANCIAL DATA	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
UNAUDITED CONSOLIDATED QUARTERLY FINANCIAL DATA	UNAUDITED CONSOLIDATED QUARTERLY FINANCIAL DATA In management's opinion, the following quarterly financial information fairly presents the results of operations for such periods and is prepared on a basis consistent with our annual audited financial statements. (In millions, except for per-share amounts) March 31, June 30, September 30, December 31, Net premium income $ 4,432 $ 4,364 $ 4,380 $ 4,394 Net investment income 782 777 784 792 Realized investment gains (losses) 13 127 (114 ) 114 Other income (loss) (1 ) 19 (10 ) 19 Total revenues 5,226 5,287 5,040 5,319 Total benefits and expenses 4,213 4,413 4,176 4,209 Earnings before income taxes 1,013 874 864 1,110 Total income tax 350 301 297 380 Net earnings $ 663 $ 573 $ 567 $ 730 Net earnings per basic share $ 1.52 $ 1.33 $ 1.32 $ 1.72 Net earnings per diluted share 1.51 1.32 1.32 1.71 Quarterly amounts may not agree in total to the corresponding annual amounts due to rounding. (In millions, except for per-share amounts) March 31, June 30, September 30, December 31, Net premium income $ 4,854 $ 4,888 $ 4,841 $ 4,489 Net investment income 827 843 841 808 Realized investment gains (losses) (46 ) 102 16 143 Other income 5 5 38 74 Total revenues 5,640 5,838 5,736 5,514 Total benefits and expenses 4,536 4,600 4,662 4,439 Earnings before income taxes 1,104 1,238 1,074 1,075 Total income tax 372 428 368 372 Net earnings $ 732 $ 810 $ 706 $ 703 Net earnings per basic share $ 1.61 $ 1.79 $ 1.56 $ 1.57 Net earnings per diluted share 1.60 1.78 1.56 1.57 Quarterly amounts may not agree in total to the corresponding annual amounts due to rounding.

SCHEDULE II CONDENSED FINANCIAL

SCHEDULE II CONDENSED FINANCIAL INFORMATION OF REGISTRANT	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
SCHEDULE II CONDENSED FINANCIAL INFORMATION OF REGISTRANT	SCHEDULE II CONDENSED FINANCIAL INFORMATION OF REGISTRANT Aflac Incorporated (Parent Only) Condensed Statements of Earnings Years ended December 31, (In millions) 2015 2014 2013 Revenues: Dividends from subsidiaries (1) $ 2,393 $ 1,483 $ 962 Management and service fees from subsidiaries (1) 260 272 292 Net investment income 22 13 11 Interest from subsidiaries (1) 6 6 7 Realized investment gains (losses) 86 45 10 Change in fair value of the cross-currency interest rate swaps (53 ) 314 274 Other income (loss) 0 (11 ) 1 Total revenues 2,714 2,122 1,557 Operating expenses: Interest expense 231 243 208 Other operating expenses 321 (2) 88 79 Total operating expenses 552 331 287 Earnings before income taxes and equity in undistributed earnings of 2,162 1,791 1,270 Income tax expense (benefit): Current 2 1 0 Deferred (82 ) 120 98 Total income taxes (80 ) 121 98 Earnings before equity in undistributed earnings of subsidiaries 2,242 1,670 1,172 Equity in undistributed earnings of subsidiaries (1) 291 1,281 1,986 Net earnings $ 2,533 $ 2,951 $ 3,158 (1) Eliminated in consolidation (2) Includes expense of $230 for the make-whole payment associated with the early extinguishment of debt See the accompanying Notes to Condensed Financial Statements. See the accompanying Report of Independent Registered Public Accounting Firm. SCHEDULE II CONDENSED FINANCIAL INFORMATION OF REGISTRANT Aflac Incorporated (Parent Only) Condensed Statements of Comprehensive Income (Loss) Years ended December 31, (In millions) 2015 2014 2013 Net earnings $ 2,533 $ 2,951 $ 3,158 Other comprehensive income (loss) before income taxes: Foreign currency translation adjustments: Unrealized foreign currency translation gains (losses) 3 39 48 Equity in unrealized foreign currency translation gains (losses) of 357 (1,494 ) (1,636 ) Unrealized gains (losses) on investment securities: Unrealized holding gains (losses) on investment securities (8 ) 9 (12 ) Equity in unrealized holding gains (losses) on investment securities (2,526 ) 5,938 (2,350 ) Equity in reclassification adjustment for realized (gains) losses of (61 ) (54 ) (56 ) Unrealized gains (losses) on derivatives during period 0 (17 ) (10 ) Pension liability adjustment during period (20 ) (76 ) 157 Total other comprehensive income (loss) before (2,255 ) 4,345 (3,859 ) Income tax expense (benefit) related to items of other comprehensive (901 ) 1,803 (581 ) Other comprehensive income (loss), net of income taxes (1,354 ) 2,542 (3,278 ) Total comprehensive income (loss) $ 1,179 $ 5,493 $ (120 ) See the accompanying Notes to Condensed Financial Statements. See the accompanying Report of Independent Registered Public Accounting Firm. SCHEDULE II CONDENSED FINANCIAL INFORMATION OF REGISTRANT Aflac Incorporated (Parent Only) Condensed Balance Sheets December 31, (In millions, except for share and per-share amounts) 2015 2014 Assets: Investments and cash: Fixed maturity securities available for sale, at fair value $ 493 $ 437 Investments in subsidiaries (1) 20,500 21,430 Other investments 9 24 Cash and cash equivalents 1,721 1,638 Total investments and cash 22,723 23,529 Due from subsidiaries (1) 113 116 Other assets 582 766 Total assets $ 23,418 $ 24,411 Liabilities and shareholders' equity: Liabilities: Income taxes $ 8 $ 6 Employee benefit plans 274 282 Notes payable 5,008 5,285 Other liabilities 420 491 Total liabilities 5,710 6,064 Shareholders' equity: Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 67 67 Additional paid-in capital 1,828 1,711 Retained earnings 24,007 22,156 Accumulated other comprehensive income (loss): Unrealized foreign currency translation gains (2,196 ) (2,541 ) Unrealized gains (losses) on investment securities 2,986 4,672 Unrealized gains (losses) on derivatives (26 ) (26 ) Pension liability adjustment (139 ) (126 ) Treasury stock, at average cost (8,819 ) (7,566 ) Total shareholders' equity 17,708 18,347 Total liabilities and shareholders' equity $ 23,418 $ 24,411 (1) Eliminated in consolidation See the accompanying Notes to Condensed Financial Statements. See the accompanying Report of Independent Registered Public Accounting Firm. SCHEDULE II CONDENSED FINANCIAL INFORMATION OF REGISTRANT Aflac Incorporated (Parent Only) Condensed Statements of Cash Flows Years ended December 31, (In millions) 2015 2014 2013 Cash flows from operating activities: Net earnings $ 2,533 $ 2,951 $ 3,158 Adjustments to reconcile net earnings to net cash provided from Equity in undistributed earnings of subsidiaries (1) (291 ) (1,281 ) (1,986 ) Change in income tax liabilities 6 115 155 Other, net 149 (2 ) (72 ) 11 Net cash provided (used) by operating activities 2,397 1,713 1,338 Cash flows from investing activities: Fixed maturity securities sold 121 38 8 Fixed maturity securities purchased (202 ) (105 ) (206 ) Other investments sold (purchased) 14 291 (298 ) Settlement of derivatives 147 (1 ) 0 Additional capitalization of subsidiaries (1) (43 ) 0 0 Net cash provided (used) by investing activities 37 223 (496 ) Cash flows from financing activities: Purchases of treasury stock (1,315 ) (1,210 ) (813 ) Proceeds from borrowings 998 750 700 Principal payments under debt obligations (1,272 ) (335 ) 0 Dividends paid to shareholders (656 ) (654 ) (635 ) Treasury stock reissued 36 33 88 Proceeds from exercise of stock options 47 23 41 Net change in amount due to/from subsidiaries (1) 43 14 28 Other, net (232 ) (2 ) 0 0 Net cash provided (used) by financing activities (2,351 ) (1,379 ) (591 ) Net change in cash and cash equivalents 83 557 251 Cash and cash equivalents, beginning of period 1,638 1,081 830 Cash and cash equivalents, end of period $ 1,721 $ 1,638 $ 1,081 (1) Eliminated in consolidation (2) Operating activities excludes and financing activities includes a cash outflow of $230 for the make-whole payment associated with the early extinguishment of debt See the accompanying Notes to Condensed Financial Statements. See the accompanying Report of Independent Registered Public Accounting Firm. (A) Notes Payable A summary of notes payable as of December 31 follows: (In millions) 2015 2014 3.45% senior notes paid August 2015 $ 0 $ 300 2.65% senior notes due February 2017 652 (1) 653 (1) 8.50% senior notes due May 2019 0 (2) 850 2.40% senior notes due March 2020 550 0 4.00% senior notes due February 2022 350 350 3.625% senior notes due June 2023 700 700 3.625% senior notes due November 2024 749 (3) 749 (3) 3.25% senior notes due March 2025 448 (3) 0 6.90% senior notes due December 2039 397 (3) 397 (3) 6.45% senior notes due August 2040 448 (3) 448 (3) 5.50% subordinated debentures due September 2052 500 500 Yen-denominated Uridashi notes: 2.26% notes due September 2016 (principal amount 10 billion yen) 83 83 Yen-denominated Samurai notes: 1.84% notes due July 2016 (principal amount 15.8 billion yen) 131 131 Yen-denominated loans: 3.60% loan paid July 2015 (principal amount 10 billion yen) 0 83 3.00% loan paid August 2015 (principal amount 5 billion yen) 0 41 Total notes payable $ 5,008 $ 5,285 (1) Principal amount plus an issuance premium that is being amortized over the life of the notes (2) Redeemed in April 2015 (3) Principal amount net of an issuance discount that is being amortized over the life of the notes During 2009 , Aflac Japan bought on the open market 2.0 billion yen of yen-denominated Uridashi notes issued by the Parent Company which are outstanding as of December 31, 2015 . In consolidation, those notes have been extinguished; however, they remain an outstanding liability for the Parent Company until their maturity date. The aggregate contractual maturities of notes payable during each of the years after December 31, 2015 , are as follows: (In millions) 2016 $ 214 2017 650 2018 0 2019 0 2020 550 Thereafter 3,600 Total $ 5,014 For further information regarding notes payable, see Note 9 of the Notes to the Consolidated Financial Statements. (B) Derivatives At December 31, 2015 , the Parent Company's outstanding freestanding derivative contracts were swaps associated with our notes payable, consisting of cross-currency interest rate swaps, also referred to as foreign currency swaps, associated with our senior notes due in February 2017, March 2020, February 2022, June 2023, November 2024 and March 2025, and subordinated debentures due in September 2052. We do not use derivative financial instruments for trading purposes, nor do we engage in leveraged derivative transactions. For further information regarding these derivatives, see Notes 1, 4 and 9 of the Notes to the Consolidated Financial Statements. (C) Income Taxes The Parent Company and its eligible U.S. subsidiaries file a consolidated U.S. federal income tax return. Income tax liabilities or benefits are recorded by each principal subsidiary based upon separate return calculations, and any difference between the consolidated provision and the aggregate amounts recorded by the subsidiaries is reflected in the Parent Company financial statements. For further information on income taxes, see Note 10 of the Notes to the Consolidated Financial Statements. (D) Dividend Restrictions See Note 13 of the Notes to the Consolidated Financial Statements for information regarding dividend restrictions. (E) Supplemental Disclosures of Cash Flow Information (In millions) 2015 2014 2013 Interest paid $ 235 $ 241 $ 205 Noncash financing activities: Treasury stock issued for shareholder dividend reinvestment 26 26 25

SCHEDULE III SUPPLEMENTARY INSU

SCHEDULE III SUPPLEMENTARY INSURANCE INFORMATION	12 Months Ended
	Dec. 31, 2015
Supplementary Insurance Information [Abstract]
SCHEDULE III SUPPLEMENTARY INSURANCE INFORMATION	SCHEDULE III SUPPLEMENTARY INSURANCE INFORMATION Aflac Incorporated and Subsidiaries Years ended December 31, (In millions) Deferred Policy Future Policy Unearned Other 2015: Aflac Japan $ 5,370 $ 64,437 $ 7,739 $ 6,285 Aflac U.S. 3,141 9,696 118 0 All other 0 43 0 0 Intercompany eliminations 0 (687 ) 0 0 Total $ 8,511 $ 73,489 $ 7,857 $ 6,285 2014: Aflac Japan $ 5,211 $ 60,036 $ 8,509 $ 6,030 Aflac U.S. 3,062 9,239 117 0 All other 0 1 0 1 Total $ 8,273 $ 69,276 $ 8,626 $ 6,031 Segment amounts may not agree in total to the corresponding consolidated amounts due to rounding. Years Ended December 31, (In millions) Net Net Benefits and Amortization of Other Premiums 2015: Aflac Japan $ 12,046 $ 2,436 $ 8,705 $ 578 $ 2,055 $ 11,740 Aflac U.S. 5,347 678 2,873 488 1,570 5,343 All other 177 21 168 0 573 0 Total $ 17,570 $ 3,135 $ 11,746 $ 1,066 $ 4,198 $ 17,083 2014: Aflac Japan $ 13,861 $ 2,662 $ 10,084 $ 649 $ 2,364 $ 13,352 Aflac U.S. 5,211 645 2,853 459 1,474 5,198 All other 0 12 0 0 354 0 Total $ 19,072 $ 3,319 $ 12,937 $ 1,108 $ 4,192 $ 18,550 2013: Aflac Japan $ 14,982 $ 2,651 $ 10,924 $ 641 $ 2,495 $ 15,960 Aflac U.S. 5,153 632 2,889 433 1,431 5,144 All other 0 10 0 0 310 0 Total $ 20,135 $ 3,293 $ 13,813 $ 1,074 $ 4,236 $ 21,104 Segment amounts may not agree in total to the corresponding consolidated amounts due to rounding. See the accompanying Report of Independent Registered Public Accounting Firm.

SCHEDULE IV REINSURANCE

SCHEDULE IV REINSURANCE	12 Months Ended
	Dec. 31, 2015
Reinsurance Disclosures [Abstract]
SCHEDULE IV REINSURANCE	SCHEDULE IV REINSURANCE Aflac Incorporated and Subsidiaries Years Ended December 31, (In millions) Gross Ceded to Assumed Net Percentage 2015: Life insurance in force $ 146,610 $ 3,547 $ 0 $ 143,063 0 % Premiums: Health insurance $ 13,604 $ 509 $ 186 $ 13,281 1 % Life insurance 4,300 11 0 4,289 0 Total earned premiums $ 17,904 $ 520 $ 186 $ 17,570 1 % 2014: Life insurance in force $ 144,374 $ 3,298 $ 0 $ 141,076 0 % Premiums: Health insurance $ 14,648 $ 339 $ 10 $ 14,319 0 % Life insurance 4,764 11 0 4,753 0 Total earned premiums $ 19,412 $ 350 $ 10 $ 19,072 0 % 2013: Life insurance in force $ 157,022 $ 3,245 $ 0 $ 153,777 0 % Premiums: Health insurance $ 15,393 $ 98 $ 12 $ 15,307 0 % Life insurance 4,840 12 0 4,828 0 Total earned premiums $ 20,233 $ 110 $ 12 $ 20,135 0 % Premiums by type may not agree in total to the corresponding consolidated amounts due to rounding. See the accompanying Report of Independent Registered Public Accounting Firm.

SUMMARY OF SIGNIFICANT ACCOUN28

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Description of Business   Aflac Incorporated (the Parent Company) and its subsidiaries (collectively, the Company) primarily sell supplemental health and life insurance in the United States and Japan. The Company's insurance business is marketed and administered through American Family Life Assurance Company of Columbus (Aflac), which operates in the United States (Aflac U.S.) and as a branch in Japan (Aflac Japan). American Family Life Assurance Company of New York (Aflac New York) is a wholly owned subsidiary of Aflac. Most of Aflac's policies are individually underwritten and marketed through independent agents. Additionally, Aflac U.S. markets and administers group products through Continental American Insurance Company (CAIC), branded as Aflac Group Insurance. Our insurance operations in the United States and our branch in Japan service the two markets for our insurance business. Aflac Japan's revenues, including realized gains and losses on its investment portfolio, accounted for 70% of the Company's total revenues in 2015 , compared with 72% in 2014 and 74% in 2013 . The percentage of the Company's total assets attributable to Aflac Japan was 83% at December 31, 2015 , compared with 82% at December 31, 2014 . Basis of Presentation We prepare our financial statements in accordance with U.S. generally accepted accounting principles (GAAP). These principles are established primarily by the Financial Accounting Standards Board (FASB). In these Notes to the Consolidated Financial Statements, references to U.S. GAAP issued by the FASB are derived from the FASB Accounting Standards Codification TM (ASC). The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates when recording transactions resulting from business operations based on currently available information. The most significant items on our balance sheet that involve a greater degree of accounting estimates and actuarial determinations subject to changes in the future are the valuation of investments, deferred policy acquisition costs, liabilities for future policy benefits and unpaid policy claims, and income taxes. These accounting estimates and actuarial determinations are sensitive to market conditions, investment yields, mortality, morbidity, commission and other acquisition expenses, and terminations by policyholders. As additional information becomes available, or actual amounts are determinable, the recorded estimates will be revised and reflected in operating results. Although some variability is inherent in these estimates, we believe the amounts provided are adequate. The consolidated financial statements include the accounts of the Parent Company, its subsidiaries and those entities required to be consolidated under applicable accounting standards. All material intercompany accounts and transactions have been eliminated.
Translation of Foreign Currencies	Translation of Foreign Currencies:  The functional currency of Aflac Japan's insurance operations is the Japanese yen. We translate our yen-denominated financial statement accounts into U.S. dollars as follows. Assets and liabilities are translated at end-of-period exchange rates. Realized gains and losses on security transactions are translated at the exchange rate on the trade date of each transaction. Other revenues, expenses and cash flows are translated using average exchange rates for the period. The resulting currency translation adjustments are reported in accumulated other comprehensive income. We include in earnings the realized currency exchange gains and losses resulting from foreign currency transactions. Prior to October 1, 2013, Aflac Japan maintained an investment portfolio of U.S. dollar-denominated securities on behalf of Aflac U.S., which served as an economic currency hedge of a portion of our investment in Aflac Japan. The functional currency for these investments was the U.S. dollar. The related investment income and realized/unrealized investment gains and losses were denominated in U.S. dollars. Since the functional currency of this portfolio was the U.S. dollar, there was no translation adjustment to record in other comprehensive income for these investments when the yen/dollar exchange rate changed. The foreign exchange gains and losses related to this portfolio continue to be taxable in Japan and the U.S. when the securities matured or were sold. Until maturity or sale, deferred tax expense or benefit associated with the foreign exchange gains or losses is recognized in income tax expense on other comprehensive income. As of October 1, 2013, these investments were transferred into the Aflac Japan investment portfolio. These investments began to have remeasurement and translation effects recorded in other comprehensive income in the fourth quarter of 2013. We have designated a majority of the Parent Company's yen-denominated liabilities (Samurai and Uridashi notes and yen-denominated loans) as non-derivative hedges and designated foreign currency forwards and options as derivative hedges of the foreign currency exposure of our investment in Aflac Japan. Outstanding principal and related accrued interest on these Parent Company liabilities and the fair value of these derivatives are translated into U.S. dollars at end-of-period exchange rates. Currency translation adjustments and changes in the fair value of these derivatives are recorded as unrealized foreign currency translation gains (losses) in other comprehensive income and are included in accumulated other comprehensive income.
Insurance Revenue and Expense Recognition	Insurance Revenue and Expense Recognition:  The supplemental health and life insurance policies we issue are classified as long-duration contracts. The contract provisions generally cannot be changed or canceled during the contract period; however, we may adjust premiums for supplemental health policies issued in the United States within prescribed guidelines and with the approval of state insurance regulatory authorities. Insurance premiums for most of the Company's health and life policies are recognized ratably as earned income over the premium payment periods of the policies. When revenues are reported, the related amounts of benefits and expenses are charged against such revenues, so that profits are recognized in proportion to premium revenues during the period the policies are expected to remain in force. This association is accomplished by means of annual additions to the liability for future policy benefits and the deferral and subsequent amortization of policy acquisition costs. Premiums from the Company's products with limited-pay features are collected over a significantly shorter period than the period over which benefits are provided. Premiums for these products are recognized ratably over the scheduled premium payment period. At the policyholder's option, customers can also pay discounted advanced premiums for certain of these products. Advanced premiums are deferred and recognized ratably over the regularly scheduled premium payment period. For the Company's limited-pay products, any gross premium in excess of the net premium is deferred during the scheduled premium payment period and recognized into benefits in a constant relationship with insurance in force. Benefits are recorded as an expense when they are incurred. A liability for future policy benefits is recorded when premiums are recognized using the net premium method. The calculation of deferred policy acquisition costs (DAC) and the liability for future policy benefits requires the use of estimates based on sound actuarial valuation techniques. For new policy issues, we review our actuarial assumptions and deferrable acquisition costs each year and revise them when necessary to more closely reflect recent experience and studies of actual acquisition costs. For policies in force, we evaluate DAC by major product groupings to determine that they are recoverable from future revenues, and any amounts determined not to be recoverable are charged against net earnings. We have not had any material charges to earnings for DAC that was determined not to be recoverable in any of the years presented in this Form 10-K. Advertising expense is reported as incurred in insurance expenses in the consolidated statements of earnings.
Cash and Cash Equivalents	Cash and Cash Equivalents:  Cash and cash equivalents include cash on hand, money market instruments and other debt instruments with a maturity of 90 days or less when purchased.
Investments	Investments:  Our debt securities consist of fixed-maturity securities, which are classified as either held to maturity or available for sale. Securities classified as held to maturity are securities that we have the ability and intent to hold to maturity or redemption and are carried at amortized cost. All other fixed-maturity debt securities, our perpetual securities and our equity securities are classified as available for sale and are carried at fair value. If the fair value is higher than the amortized cost for debt and perpetual securities, or the purchase cost for equity securities, the excess is an unrealized gain, and if lower than cost, the difference is an unrealized loss. The net unrealized gains and losses on securities available for sale, plus the unamortized unrealized gains and losses on debt securities transferred to the held-to-maturity portfolio, less related deferred income taxes, are recorded through other comprehensive income and included in accumulated other comprehensive income. Amortized cost of debt and perpetual securities is based on our purchase price adjusted for accrual of discount, or amortization of premium, and recognition of impairment charges, if any. The amortized cost of debt and perpetual securities we purchase at a discount or premium will equal the face or par value at maturity or the call date, if applicable. Interest is reported as income when earned and is adjusted for amortization of any premium or discount. We have investments in variable interest entities (VIEs). Criteria for evaluating VIEs for consolidation focuses on identifying which enterprise has the power to direct the activities of a variable interest entity that most significantly impact the entity's economic performance and (1) the obligation to absorb losses of the entity or (2) the right to receive benefits from the entity. We are the primary beneficiary of certain VIEs. While the VIEs generally operate within a defined set of documents, there are certain powers that are retained by us that are considered significant in our conclusion that we are the primary beneficiary. These powers vary by structure but generally include the initial selection of the underlying collateral or, for collateralized debt obligations (CDOs), the reference credits to include in the structure; the ability to obtain the underlying collateral in the event of default; and the ability to appoint or dismiss key parties in the structure. In particular, our powers surrounding the underlying collateral were the most significant powers since those most significantly impact the economics of the VIE. We have no obligation to provide any continuing financial support to any of the entities in which we are the primary beneficiary. Our maximum loss is limited to our original investment. Neither we nor any of our creditors have the ability to obtain the underlying collateral, nor do we have control over the instruments in the VIEs, unless there is an event of default. For those entities where we are the primary beneficiary, the assets consolidated are fixed-maturity securities, perpetual securities, equity securities, and derivative instruments; collateral is reported separately under the captions fixed maturities- and perpetual securities- consolidated variable interest entities on our balance sheet. For the mortgage- and asset-backed securities held in our fixed maturities portfolio, we recognize income using a constant effective yield, which is based on anticipated prepayments and the estimated economic life of the securities. When estimates of prepayments change, the effective yield is recalculated to reflect actual payments to date and anticipated future payments. The net investment in mortgage- and asset-backed securities is adjusted to the amount that would have existed had the new effective yield been applied at the time of acquisition. This adjustment is reflected in net investment income. We use the specific identification method to determine the gain or loss from securities transactions and report the realized gain or loss in the consolidated statements of earnings. Securities transactions are accounted for based on values as of the trade date of the transaction. An investment in a fixed maturity, perpetual security or equity security is impaired if the fair value falls below book value. We regularly review our entire investment portfolio for declines in value. Our fixed maturities and investment-grade perpetual securities investments are evaluated for other-than-temporary impairment using our debt impairment model. Our debt impairment model focuses on the ultimate collection of the cash flows from our investments. The determination of the amount of impairments under this model is based upon our periodic evaluation and assessment of known and inherent risks associated with the respective securities. Such evaluations and assessments are revised as conditions change and new information becomes available. The determination of whether an impairment in value of our debt securities is other than temporary is based largely on our evaluation of the issuer ' s creditworthiness. We must apply considerable judgment in determining the likelihood of the security recovering in value while we own it. Factors that may influence this include the overall level of interest rates, credit spreads, the credit quality of the underlying issuer, and other factors. This process requires consideration of risks which can be controlled to a certain extent, such as credit risk, and risks which cannot be controlled, such as interest rate risk. If, after monitoring and analyses, management believes that fair value will not recover to amortized cost prior to the disposal of the security, we recognize an other-than-temporary impairment of the security. Once a security is considered to be other-than-temporarily impaired, the impairment loss is separated into two separate components: the portion of the impairment related to credit and the portion of the impairment related to factors other than credit. We recognize a charge to earnings for the credit-related portion of other-than-temporary impairments. Impairments related to factors other than credit are charged to earnings in the event we intend to sell the security prior to the recovery of its amortized cost or if it is more likely than not that we would be required to dispose of the security prior to recovery of its amortized cost; otherwise, non-credit-related other-than-temporary impairments are charged to other comprehensive income. Our investments in perpetual securities that are rated below investment grade and equity securities are evaluated for other-than-temporary impairment under our equity impairment model. Our equity impairment model focuses on the severity of a security's decline in fair value coupled with the length of time the fair value of the security has been below amortized cost and the financial condition and near-term prospects of the issuer. For equity securities that have declines in value that are deemed to be temporary, we make an assertion as to our ability and intent to retain the security until recovery. Once identified, these equity securities are restricted from trading unless authorized based upon events that could not have been foreseen at the time we asserted our ability and intent to retain the security until recovery. If management believes that the equity security will not recover prior to the disposal of the security, we recognize an other-than-temporary impairment of the security. Once an equity security is considered to be other-than-temporarily impaired, its fair value on that date becomes the new cost basis and the impairment loss is recognized in earnings. We lend fixed-maturity securities to financial institutions in short-term security lending transactions. These securities continue to be carried as investment assets on our balance sheet during the terms of the loans and are not reported as sales. We receive cash or other securities as collateral for such loans. For loans involving unrestricted cash or securities as collateral, the collateral is reported as an asset with a corresponding liability for the return of the collateral. Other investments include policy loans, middle market loans, and other short-term investments with maturities of one year or less, but greater than 90 days, at the time of purchase and are stated at amortized cost, which approximates estimated fair value. We invest in middle market loans through participation rights that are accounted for as loan receivables and recorded at amortized cost on the acquisition date. Since we have the intent and ability to hold these loan receivables for the foreseeable future or until they mature, they are considered held for investment and are carried at adjusted amortized cost in the other investments line on our consolidated balance sheets. The adjusted amortized cost of the loan receivables reflects allowances for expected incurred losses estimated based on past events and current economic conditions as of each reporting date.
Derivatives and Hedging	Derivatives and Hedging:  Freestanding derivative instruments are reported in the consolidated balance sheet at fair value and are reported in other assets and other liabilities, with changes in value reported in earnings and/or other comprehensive income. These freestanding derivatives are interest rate swaps, foreign currency swaps, credit default swaps (CDSs), foreign currency forwards, foreign currency options, and options on interest rate swaps (or interest rate swaptions). Interest rate and foreign currency swaps are used within VIEs to hedge the risk arising from interest rate and currency exchange risk, while the CDSs are used to increase the yield and improve the diversification of the portfolio. Foreign currency forwards and options are used in hedging foreign exchange risk on U.S. dollar-denominated securities in Aflac Japan's portfolio. Foreign currency forwards and options are used to hedge certain portions of forecasted cash flows denominated in yen. Interest rate swaps are used to hedge the variability of interest cash flows associated with our variable interest rate notes. Cross-currency interest rate swaps, also referred to as foreign currency swaps, are used to economically convert certain U.S. dollar-denominated note obligations into yen-denominated principal and interest obligations. Interest rate swaptions have been used to hedge interest rate risk for certain U.S. dollar-denominated available-for-sale securities. We do not use derivatives for trading purposes, nor do we engage in leveraged derivative transactions. From time to time, we purchase certain investments that contain an embedded derivative. We assess whether this embedded derivative is clearly and closely related to the asset that serves as its host contract. If we deem that the embedded derivative's terms are not clearly and closely related to the host contract, and a separate instrument with the same terms would qualify as a derivative instrument, the derivative is separated from that contract, held at fair value and reported with the host instrument in the consolidated balance sheet, with changes in fair value reported in earnings. If we have elected the fair value option, the embedded derivative is not bifurcated, and the entire investment is held at fair value with changes in fair value reported in earnings. For those relationships where we seek hedge accounting, we formally document all relationships between hedging instruments and hedged items, as well as our risk-management objectives and strategies for undertaking various hedge transactions. This process includes linking derivatives and non-derivative financial instruments that are designated as hedges to specific assets or liabilities on the balance sheet. We also assess, both at inception and on an ongoing basis, whether the derivatives and non-derivative financial instruments used in hedging activities are highly effective in offsetting changes in fair values or cash flows of the hedged items. The assessment of hedge effectiveness determines the accounting treatment of noncash changes in fair value. Changes in the fair value of any of our derivatives that are designated and qualify as cash flow hedges are recorded in other comprehensive income as long as they are deemed effective. Any hedge ineffectiveness is recorded immediately in current period earnings within derivative and other gains (losses). Periodic derivative net coupon settlements are recorded in the line item of the consolidated statements of earnings in which the cash flows of the hedged item are recorded. Changes in the estimated fair value of derivative instruments that are designated and qualify as fair value hedges, including amounts measured as ineffectiveness, and changes in the estimated fair value of the hedged item related to the designated risk being hedged, are reported in current earnings within derivative and other gains (losses). We have designated the majority of the Parent Company's yen-denominated liabilities (Samurai and Uridashi notes and yen-denominated loans) as non-derivative hedges and designated certain derivatives as hedges of the foreign currency exposure to our investment in Aflac Japan. At the beginning of each quarter, we make our net investment hedge designation. If the total of the designated Parent Company non-derivative and derivatives notional is equal to or less than our net investment in Aflac Japan, the hedge is deemed to be effective, and the exchange effect on the yen-denominated liabilities and the change in estimated fair value of the derivatives are reported in the unrealized foreign currency component of other comprehensive income. Should these designated net investment hedge positions exceed our net investment in Aflac Japan, the foreign exchange effect on the portion that exceeds our investment in Aflac Japan would be recognized in current earnings within derivative and other gains (losses). Derivatives that are not designated as hedges are carried at fair value with all changes in fair value recorded in current period earnings within derivative and other gains (losses). We include the fair value of all freestanding derivatives in either other assets or other liabilities on the balance sheet. We receive and pledge cash or other securities as collateral on open derivative positions. Cash received as collateral is reported as an asset with a corresponding liability for the return of the collateral. Cash pledged as collateral is recorded as a reduction to cash, and a corresponding receivable is recognized for the return of the cash collateral. We generally can repledge or resell collateral obtained by us, although we do not typically exercise such rights. Securities received as collateral are not recognized unless we were to exercise our right to sell that collateral or exercise remedies on that collateral upon a counterparty default. Securities that we have pledged as collateral continue to be carried as investment assets on our balance sheet.
Deferred Policy Acquisition Costs	Deferred Policy Acquisition Costs: Certain direct and incremental costs of acquiring new business are deferred and amortized with interest over the premium payment periods in proportion to the ratio of annual premium income to total anticipated premium income. Anticipated premium income is estimated by using the same mortality, persistency and interest assumptions used in computing liabilities for future policy benefits. In this manner, the related acquisition expenses are matched with revenues. Deferred costs include the excess of current-year commissions over ultimate renewal-year commissions and certain incremental direct policy issue, underwriting and sales expenses. All of these incremental costs are directly related to successful policy acquisition. For some products, policyholders can elect to modify product benefits, features, rights or coverages by exchanging a contract for a new contract or by amendment, endorsement, or rider to a contract, or by the election of a feature or coverage within a contract. These transactions are known as internal replacements. For internal replacement transactions where the resulting contract is substantially unchanged, the policy is accounted for as a continuation of the replaced contract. Unamortized deferred acquisition costs from the original policy continue to be amortized over the expected life of the new policy, and the costs of replacing the policy are accounted for as policy maintenance costs and expensed as incurred. Internal replacement transactions that result in a policy that is not substantially unchanged are accounted for as an extinguishment of the original policy and the issuance of a new policy. Unamortized deferred acquisition costs on the original policy that was replaced are immediately expensed, and the costs of acquiring the new policy are capitalized and amortized in accordance with our accounting policies for deferred acquisition costs. We measure the recoverability of DAC and the adequacy of our policy reserves annually by performing gross premium valuations on our business. Our testing indicates that our DAC is recoverable and our policy liabilities are adequate. (See the following discussion for further information regarding policy liabilities.)
Policy Liabilities - Future Policy Benefits	Policy Liabilities:  Future policy benefits represent claims that are expected to occur in the future and are computed by a net level premium method using estimated future investment yields, persistency and recognized morbidity and mortality tables modified to reflect our experience, including a provision for adverse deviation. These assumptions are generally established at the time a policy is issued.
Policy Liabilities - Unpaid Policy Claims	Unpaid policy claims are estimates computed on an undiscounted basis using statistical analyses of historical claims experience adjusted for current trends and changed conditions. The ultimate liability may vary significantly from such estimates. We regularly adjust these estimates as new claims experience emerges and reflect the changes in operating results in the year such adjustments are made.
Other Policy Liabilities	Other policy liabilities consist primarily of discounted advance premiums on deposit from policyholders in conjunction with their purchase of certain Aflac Japan limited-pay insurance products. These advanced premiums are deferred upon collection and recognized as premium revenue over the contractual premium payment period.
Internal Replacements of Insurance Contracts	For internal replacements that are determined to not be substantially unchanged, policy liabilities related to the original policy that was replaced are immediately released, and policy liabilities are established for the new insurance contract.
Reinsurance Accounting Policy	Reinsurance: We enter into reinsurance agreements with other companies in the normal course of business. For each of our reinsurance agreements, we determine if the agreement provides indemnification against loss or liability relating to insurance risk in accordance with applicable accounting standards. Reinsurance premiums and benefits paid or provided are accounted for on bases consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Premiums, benefits and DAC are reported net of insurance ceded. See Note 8 of the Notes to the Consolidated Financial Statements for additional information.
Income Taxes	Income Taxes: Income tax provisions are generally based on pretax earnings reported for financial statement purposes, which differ from those amounts used in preparing our income tax returns. Deferred income taxes are recognized for temporary differences between the financial reporting basis and income tax basis of assets and liabilities, based on enacted tax laws and statutory tax rates applicable to the periods in which we expect the temporary differences to reverse. We record deferred tax assets for tax positions taken based on our assessment of whether the tax position is more likely than not to be sustained upon examination by taxing authorities. A valuation allowance is established for deferred tax assets when it is more likely than not that an amount will not be realized. As discussed in the Translation of Foreign Currencies section above, Aflac Japan maintains certain dollar-denominated investments that, prior to October 1, 2013, did not have any foreign currency translation adjustments recognized in other comprehensive income. However, the deferred tax expense or benefit associated with foreign exchange gains or losses on these investments is recognized in other comprehensive income (loss) until the securities mature or are sold. Total income tax expense (benefit) related to items of other comprehensive income (loss) included a deferred tax expense of $614 million in 2013 for these U.S. dollar-denominated investments. Excluding these amounts from total taxes on other comprehensive income would result in an effective income tax rate on pretax other comprehensive income (loss) of 31% in 2013.
Policyholder Protection Corporation and State Guaranty Association Assessments	Policyholder Protection Corporation and State Guaranty Association Assessments: In Japan, the government has required the insurance industry to contribute to a policyholder protection corporation. We recognize a charge for our estimated share of the industry's obligation once it is determinable. We review the estimated liability for policyholder protection corporation contributions on an annual basis and report any adjustments in Aflac Japan's expenses. In the United States, each state has a guaranty association that supports insolvent insurers operating in those states. To date, our state guaranty association assessments have not been material.
Treasury Stock	Treasury Stock: Treasury stock is reflected as a reduction of shareholders' equity at cost. We use the weighted-average purchase cost to determine the cost of treasury stock that is reissued. We include any gains and losses in additional paid-in capital when treasury stock is reissued.
Share-Based Compensation	Share-Based Compensation: We measure compensation cost related to our share-based payment transactions at fair value on the grant date, and we recognize those costs in the financial statements over the vesting period during which the employee provides service in exchange for the award.
Earnings Per Share	Earnings Per Share: We compute basic earnings per share (EPS) by dividing net earnings by the weighted-average number of unrestricted shares outstanding for the period. Diluted EPS is computed by dividing net earnings by the weighted-average number of shares outstanding for the period plus the shares representing the dilutive effect of share-based awards.
Reclassifications	Reclassifications: Certain reclassifications have been made to prior-year amounts to conform to current-year reporting classifications. These reclassifications had no impact on net earnings or total shareholders' equity.
Recently Adopted Accounting Pronouncements	New Accounting Pronouncements Recently Adopted Accounting Pronouncements Income Statement - Extraordinary and Unusual Items - Simplifying income statement presentation by eliminating the concept of extraordinary items: In January 2015, the FASB issued updated guidance that eliminates from U.S. GAAP the concept of extraordinary items. Presentation and disclosure guidance for items that are unusual in nature or occur infrequently will be retained. The amendments in this updated guidance are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted provided that the guidance is applied from the beginning of the fiscal year of adoption. We adopted this guidance as of January 1, 2015. The adoption of this guidance did not have a significant impact on our financial position, results of operations, or disclosures. Receivables - Troubled debt restructurings by creditors - classification of certain government-guaranteed mortgage loans upon foreclosure: In August 2014, the FASB issued updated guidance for troubled debt restructurings affecting creditors that hold government guaranteed mortgage loans. The guidance requires that a mortgage loan be derecognized and a separate other receivable be recognized upon foreclosure if certain conditions are met. We adopted the guidance as of January 1, 2015. The adoption of this guidance did not have a significant impact on our financial position or results of operations. Transfers and Servicing, Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures: In June 2014, the FASB issued updated guidance for repurchase agreement and security lending transactions to change the accounting for repurchase-to-maturity transactions and linked repurchase financings to be accounted for as secured borrowings, consistent with the accounting for other repurchase agreements. The amendments also require new disclosures to increase transparency about the types of collateral pledged in repurchase agreements and similar transactions accounted for as secured borrowings. We adopted accounting changes for the new guidance as of January 1, 2015, and adopted the required disclosures as of April 1, 2015. The adoption of this guidance did not have a significant impact on our financial position or results of operations. Receivables - Troubled debt restructurings by creditors - Reclassification of residential real estate collateralized consumer mortgage loans upon foreclosure: In January 2014, the FASB issued updated guidance for troubled debt restructurings clarifying when an in substance repossession or foreclosure occurs, and when a creditor is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan. We adopted the guidance as of January 1, 2015. The adoption of this guidance did not have a significant impact on our financial position or results of operations. Presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists: In July 2013, the FASB issued guidance to amend the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. The new guidance states that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. However, to the extent a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be combined with deferred tax assets. We adopted this guidance as of January 1, 2014. The adoption of this guidance did not have a significant impact on our financial position or results of operations. Derivatives and hedging: In July 2013, the FASB issued an update which allows entities to use the Federal Funds Effective Swap Rate, also referred to as the Overnight Index Swap Rate (OIS), as a benchmark interest rate for hedge accounting purposes. This update reflects the evolution of market hedging practices and is intended to provide more flexibility for hedge accounting purposes. We adopted this guidance in the third quarter of 2013 on a prospective basis for qualifying new or redesignated hedging relationships entered into on or after the effective date of July 17, 2013. The adoption of the guidance had no impact on our financial position or results of operations. Reporting of amounts reclassified out of accumulated other comprehensive income: In February 2013, the FASB issued guidance that requires reclassification adjustments for items that are reclassified out of accumulated other comprehensive income to net income to be presented in statements where the components of net income and the components of other comprehensive income are presented or in the footnotes to the financial statements. Additionally, the amendment requires cross-referencing to other disclosures currently required for other reclassification items. We adopted this guidance as of January 1, 2013. The adoption of this guidance impacted our financial statement disclosures, but it did not have an impact on our financial position or results of operations. Disclosures about offsetting assets and liabilities: In December 2011, the FASB issued guidance to amend the disclosure requirements about offsetting assets and liabilities. The new guidance clarifies the FASB's intent concerning the application of existing offsetting disclosure requirements. Entities are required to disclose gross and net information about both instruments and transactions eligible for offset in the statement of financial position and instruments and transactions when those activities are subject to an agreement similar to a master netting arrangement. The scope of this guidance was clarified and revised in January 2013 to apply to derivatives, repurchase agreements, reverse repurchase agreements, securities borrowing and securities lending arrangements. We adopted this guidance as of January 1, 2013. The adoption of this guidance impacted our financial statement disclosures, but it did not have an impact on our financial position or results of operations. Fees paid to the federal government by health insurers: In July 2011, the FASB issued guidance on the accounting for fees owed by health insurers as mandated by the Patient Protection and Affordable Care Act as amended by the Health Care and Education Reconciliation Act, which imposes an annual fee on health insurers for each calendar year beginning on or after January 1, 2014. A health insurer's portion of the annual fee is payable by September 30 of the applicable calendar year once the entity provides health insurance for any U.S. health risk in that year. The accounting guidance specifies that the liability for the fee should be estimated and recorded in full in the applicable calendar year in which the fee is payable. We adopted this guidance as of January 1, 2014. The adoption of this guidance did not have a significant impact on our financial position or results of operations.
Description of Accounting Pronouncements Pending Adoption	Accounting Pronouncements Pending Adoption Financial Instruments - Recognition and Measurement of Financial Assets and Financial Liabilities: In January 2016, the FASB issued guidance to address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The main provisions require that equity investments be measured at fair value with changes recognized in net income; that changes in instrument-specific credit risk for financial liabilities that are measured under the fair value option be recognized in other comprehensive income; and that entities would make the assessment of the ability to realize a deferred tax asset (DTA) related to an available-for-sale (AFS) debt security in combination with the entity's other DTAs. The amendments are effective for public companies for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is not permitted, with the exception of the own credit provision if an entity has elected to measure a liability at fair value. We are evaluating whether the adoption of this guidance will have a significant impact on our financial position, results of operations or disclosures. Business Combinations - Simplifying the Accounting for Measurement-Period Adjustments: In September 2015, the FASB issued guidance requiring that an acquirer recognize adjustments to estimated amounts that are identified during the measurement period in the reporting period in which the adjustments are determined. In the same period’s financial statements, the acquirer is required to record income effects of the adjustments as if the accounting had been completed at the acquisition date. The acquirer is also required to present separately on the face of the income statement or disclose in the notes the portion of the amount recorded in current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the estimated amounts had been recognized as of the acquisition date. The amendment is effective for public business entities for annual periods beginning after December 15, 2015, and interim periods within annual periods beginning after December 15, 2015. The adoption of this guidance will not have a significant impact on our financial position or results of operations. Fair Value Measurement - Disclosures for investments in certain entities that calculate net asset value per share (or its equivalent): In May 2015, the FASB issued updated guidance that removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. The amendments also remove the requirement to make certain disclosures for all investments that are eligible to be measured at fair value using the net asset value per share practical expedient. Rather, those disclosures are limited to investments for which the entity has elected to measure the fair value using that practical expedient. The amendments are effective for public business entities for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. The amendments should be applied retrospectively to all periods presented whereby an investment for which fair value is measured using the net asset value per share practical expedient be removed from the fair value hierarchy in all periods presented in an entity’s financial statements. Earlier application is permitted. The adoption of this guidance will not have a significant impact on our financial position, results of operations, or disclosures. Financial Services - Insurance - Disclosures about Short-Duration Contracts: In May 2015, the FASB issued updated guidance requiring enhanced disclosures by all insurance entities that issue short-duration contracts. The amendments require insurance entities to disclose for annual reporting periods information about the liability for unpaid claims and claim adjustment expenses. The amendments also require insurance entities to disclose information about significant changes in methodologies and assumptions used to calculate the liability for unpaid claims and claim adjustment expenses. In addition, the amendments require insurance entities to disclose for annual and interim reporting periods a roll-forward of the liability for unpaid claims and claim adjustment expenses. For health insurance claims, the amendments require the disclosure of the total of incurred-but-not-reported liabilities and expected development on reported claims included in the liability for unpaid claims and claim adjustment expenses. The amendments are effective for public business entities for annual periods beginning after December 15, 2015, and interim periods within annual periods beginning after December 15, 2016. Early application of the amendments is permitted. The adoption of this guidance will not have a significant impact on our financial position or results of operations. Interest - Imputation of Interest - Simplifying the presentation of debt issuance costs: In April 2015, the FASB issued updated guidance to simplify presentation of debt issuance costs. The updated guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by this amendment. In August 2015, the FASB issued updated SEC Staff guidance pertaining to the presentation of debt issuance costs related to line-of-credit arrangements. The guidance states that an entity may defer and present debt issuance costs as an asset, subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. The amendment is effective for annual periods and interim periods beginning after December 15, 2015. Early adoption is permitted. The adoption of this guidance will not have a significant impact on our financial position or results of operations. Consolidation - Amendments to the consolidation analysis: In February 2015, the FASB issued updated guidance that affects evaluation of whether limited partnerships and similar legal entities (limited liability corporations and securitization structures, etc.) are VIEs, evaluation of whether fees paid to a decision maker or a service provider are a variable interest, and evaluation of the effect of fee arrangements and the effect of related parties on the determination of the primary beneficiary under the VIE model for consolidation. The updated guidance eliminates the presumption that a general partner should consolidate a limited partnership. Limited partnership and similar legal entities that provide partners with either substantive kick-out rights or substantive participating rights over the general partner will now be evaluated under the voting interest model rather than the VIE model for consolidation. In situations where no single party has a controlling financial interest in a VIE, the related party relationships under common control should be considered in their entirety in determining whether that common control group has a controlling financial interest in the VIE. The amendments in the updated guidance are effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2015. Early application is permitted, including adoption in an interim period. The adoption of this guidance will result in a reduction to the number of our investments that meet the definition of a VIE and will also reduce the number of VIEs required to be disclosed within our financial statements. The adoption of this guidance will impact our footnote disclosures, but will not have a significant impact on our financial position or results of operations. Derivatives and Hedging - Determining whether the host contract in a hybrid financial instrument issued in the form of a share is more akin to debt or equity: In November 2014, the FASB issued guidance to clarify how to evaluate the economic characteristics and risks of a host contract in a hybrid financial instrument that is issued in the form of a share. The guidance also clarifies that an entity should assess the substance of the relevant terms and features when considering how to weight those terms and features. The guidance is effective for annual periods and interim periods beginning after December 15, 2015. The adoption of this guidance will not have a significant impact on our financial position or results of operations. Presentation of Financial Statements - Going Concern - Disclosure of uncertainties about an entity’s ability to continue as a going concern: In August 2014, the FASB issued this amendment that provides U.S. GAAP guidance on management’s responsibility in evaluating whether there is substantial doubt about a company’s ability to continue as a going concern and about related footnote disclosures. For each reporting period, management will be required to evaluate whether there are conditions or events that raise substantial doubt about a company’s ability to continue as a going concern within one year from the date the financial statements are issued. The amendment is effective for annual periods ending after December 15, 2016, and interim periods within annual periods beginning after December 15, 2016. Early application is permitted for annual or interim reporting periods for which the financial statements have not previously been issued. The adoption of this guidance will not have a significant impact on our financial position or results of operations. Compensation - Stock Compensation - Accounting for share-based payments when the terms of an award provide that a performance target could be achieved after the requisite service period: In June 2014, the FASB issued this amendment that provides guidance on certain share-based payment awards that require a specific performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. A reporting entity should apply existing guidance to awards with performance conditions that affect vesting to account for such awards. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. The guidance is effective for annual periods and interim periods within those annual periods beginning after December 15, 2015. Early adoption is permitted. The adoption of this guidance will not have a significant impact on our financial position or results of operations. Revenue from contracts with customers: In May 2014, the FASB issued updated guidance that affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (e.g., insurance contracts or lease contracts). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In August 2015, the FASB deferred the effective date for this standard to annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Early application is not permitted. The adoption of this guidance will not have a significant impact on our financial position or results of operations.

BUSINESS SEGMENT AND FOREIGN 29

BUSINESS SEGMENT AND FOREIGN INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Reconciliation of Revenue from Segments to Consolidated	Information regarding operations by segment for the years ended December 31 follows: (In millions) 2015 2014 2013 Revenues: Aflac Japan: Net earned premiums: Cancer $ 4,933 $ 5,596 $ 6,123 Medical and other health 3,092 3,770 4,282 Life insurance 4,021 4,495 4,577 Net investment income 2,436 2,662 2,651 Other income 31 32 55 Total Aflac Japan 14,513 16,555 17,688 Aflac U.S.: Net earned premiums: Accident/disability 2,391 2,303 2,284 Cancer 1,293 1,279 1,283 Other health 1,395 1,371 1,334 Life insurance 268 258 252 Net investment income 678 645 632 Other income 8 3 6 Total Aflac U.S. 6,033 5,859 5,791 Other business segments 225 43 49 Total business segment revenues 20,771 22,457 23,528 Realized investment gains (losses) (1) 55 171 389 Corporate 282 281 302 Intercompany eliminations (201 ) (248 ) (308 ) Other non-operating income (loss) (35 ) (2) 67 28 Total revenues $ 20,872 $ 22,728 $ 23,939 (1) Excluding a gain of $85 in 2015, $44 in 2014 and $10 in 2013 related to the interest rate component of the change in fair value of foreign currency swaps on notes payable which is classified as an operating gain when analyzing segment operations (2) Includes a loss of $20 related to the change in value of yen repatriation received in advance of settlement of certain foreign currency derivatives. The loss was offset by derivative gains included in realized investment gains (losses).
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	(In millions) 2015 2014 2013 Pretax earnings: Aflac Japan $ 3,175 $ 3,458 $ 3,628 Aflac U.S. 1,101 1,073 1,038 Other business segments 14 (2 ) (1 ) Total business segment pretax operating earnings 4,290 4,529 4,665 Interest expense, noninsurance operations (146 ) (198 ) (198 ) Corporate and eliminations (71 ) (78 ) (68 ) Pretax operating earnings 4,073 4,253 4,399 Realized investment gains (losses) (1) 55 171 389 Other non-operating income (loss) (266 ) (2),(3) 67 28 Total earnings before income taxes $ 3,862 $ 4,491 $ 4,816 Income taxes applicable to pretax operating earnings $ 1,403 $ 1,456 $ 1,512 Effect of foreign currency translation on operating earnings (198 ) (117 ) (357 ) (1) Excluding a gain of $85 in 2015, $44 in 2014 and $10 in 2013 related to the interest rate component of the change in fair value of foreign currency swaps on notes payable which is classified as an operating gain when analyzing segment operations (2) Includes a loss of $20 related to the change in value of yen repatriation received in advance of settlement of certain foreign currency derivatives. This loss was offset by derivative gains included in realized investment gains (losses). (3) Includes expense of $230 for the make-whole payment associated with the early extinguishment of debt
Reconciliation of Assets from Segment to Consolidated	Assets as of December 31 were as follows: (In millions) 2015 2014 2013 Assets: Aflac Japan $ 97,646 $ 98,525 $ 102,973 Aflac U.S. 18,537 18,383 16,112 Other business segments 188 128 155 Total business segment assets 116,371 117,036 119,240 Corporate 23,415 24,636 19,909 Intercompany eliminations (21,490 ) (21,905 ) (17,842 ) Total assets $ 118,296 $ 119,767 $ 121,307
Foreign Currency Disclosure	Yen-Translation Effects:  The following table shows the yen/dollar exchange rates used for or during the periods ended December 31 . Exchange effects were calculated using the same yen/dollar exchange rate for the current year as for each respective prior year. 2015 2014 2013 Statements of Earnings: Weighted-average yen/dollar exchange rate 120.99 105.46 97.54 Yen percent strengthening (weakening) (12.8 )% (7.5 )% (18.2 )% Exchange effect on pretax operating earnings (in millions) $ (288 ) $ (180 ) $ (534 ) 2015 2014 Balance Sheets: Yen/dollar exchange rate at December 31 120.61 120.55 Yen percent strengthening (weakening) (.05 )% (12.6 )% Exchange effect on total assets (in millions) $ (36 ) $ (10,706 ) Exchange effect on total liabilities (in millions) (41 ) (12,025 )
Schedule of Intercompany Transfers of Funds	Information on transfers for each of the years ended December 31 is shown below. See Note 13 for information concerning restrictions on transfers from Aflac Japan. (In millions) 2015 2014 2013 Management fees $ 53 $ 39 $ 37 Allocated expenses 101 71 74 Profit repatriation 2,139 1,704 771 Total transfers from Aflac Japan $ 2,293 $ 1,814 $ 882
Property, Plant and Equipment	Classes of property and equipment as of December 31 were as follows: (In millions) 2015 2014 Property and equipment: Land $ 166 $ 168 Buildings 400 393 Equipment and furniture 329 305 Total property and equipment 895 866 Less accumulated depreciation 468 437 Net property and equipment $ 427 $ 429

INVESTMENTS (Tables)

INVESTMENTS (Tables)	12 Months Ended
	Dec. 31, 2015
Schedule Of Net Investment Income	The components of net investment income for the years ended December 31 were as follows: (In millions) 2015 2014 2013 Fixed-maturity securities $ 3,094 $ 3,249 $ 3,210 Perpetual securities 114 141 153 Equity securities and other 18 7 7 Short-term investments and cash equivalents 4 2 1 Gross investment income 3,230 3,399 3,371 Less investment expenses 95 80 78 Net investment income $ 3,135 $ 3,319 $ 3,293
Available-for-sale Securities	The amortized cost for our investments in debt and perpetual securities, the cost for equity securities and the fair values of these investments at December 31 are shown in the following tables. 2015 (In millions) Cost or Gross Gross Fair Securities available for sale, carried at fair value: Fixed maturities: Yen-denominated: Japan government and agencies $ 17,293 $ 1,862 $ 0 $ 19,155 Municipalities 128 9 0 137 Mortgage- and asset-backed securities 322 33 0 355 Public utilities 1,400 210 10 1,600 Sovereign and supranational 791 180 0 971 Banks/financial institutions 2,321 325 105 2,541 Other corporate 3,337 448 33 3,752 Total yen-denominated 25,592 3,067 148 28,511 Dollar-denominated: U.S. government and agencies 110 11 0 121 Municipalities 926 151 6 1,071 Mortgage- and asset-backed securities 200 27 0 227 Public utilities 5,464 636 221 5,879 Sovereign and supranational 331 105 0 436 Banks/financial institutions 2,865 634 21 3,478 Other corporate 25,154 1,774 1,302 25,626 Total dollar-denominated 35,050 3,338 1,550 36,838 Total fixed maturities 60,642 6,405 1,698 65,349 Perpetual securities: Yen-denominated: Banks/financial institutions 1,581 143 93 1,631 Other corporate 183 22 0 205 Dollar-denominated: Banks/financial institutions 77 35 1 111 Total perpetual securities 1,841 200 94 1,947 Equity securities: Yen-denominated 472 19 4 487 Dollar-denominated 8 3 0 11 Total equity securities 480 22 4 498 Total securities available for sale $ 62,963 $ 6,627 $ 1,796 $ 67,794 2014 (In millions) Cost or Gross Gross Fair Securities available for sale, carried at fair value: Fixed maturities: Yen-denominated: Japan government and agencies $ 17,341 $ 1,740 $ 0 $ 19,081 Municipalities 88 9 0 97 Mortgage- and asset-backed securities 351 35 0 386 Public utilities 1,691 226 5 1,912 Sovereign and supranational 799 163 0 962 Banks/financial institutions 2,752 325 189 2,888 Other corporate 3,479 531 48 3,962 Total yen-denominated 26,501 3,029 242 29,288 Dollar-denominated: U.S. government and agencies 100 17 0 117 Municipalities 961 201 2 1,160 Mortgage- and asset-backed securities 185 31 0 216 Public utilities 5,061 960 36 5,985 Sovereign and supranational 343 111 0 454 Banks/financial institutions 2,943 775 8 3,710 Other corporate 22,291 2,682 330 24,643 Total dollar-denominated 31,884 4,777 376 36,285 Total fixed maturities 58,385 7,806 618 65,573 Perpetual securities: Yen-denominated: Banks/financial institutions 2,132 223 92 2,263 Other corporate 183 48 0 231 Dollar-denominated: Banks/financial institutions 125 50 0 175 Total perpetual securities 2,440 321 92 2,669 Equity securities: Yen-denominated 10 7 0 17 Dollar-denominated 9 2 0 11 Total equity securities 19 9 0 28 Total securities available for sale $ 60,844 $ 8,136 $ 710 $ 68,270
Held-to-maturity Securities	2015 (In millions) Cost or Gross Gross Fair Securities held to maturity, carried at amortized cost: Fixed maturities: Yen-denominated: Japan government and agencies $ 20,004 $ 3,387 $ 0 $ 23,391 Municipalities 341 74 0 415 Mortgage- and asset-backed securities 36 2 0 38 Public utilities 3,092 205 94 3,203 Sovereign and supranational 2,555 182 26 2,711 Banks/financial institutions 4,431 168 53 4,546 Other corporate 3,000 260 44 3,216 Total yen-denominated 33,459 4,278 217 37,520 Total securities held to maturity $ 33,459 $ 4,278 $ 217 $ 37,520 2014 (In millions) Cost or Gross Gross Fair Securities held to maturity, carried at amortized cost: Fixed maturities: Yen-denominated: Japan government and agencies $ 20,023 $ 3,195 $ 0 $ 23,218 Municipalities 346 71 0 417 Mortgage- and asset-backed securities 43 3 0 46 Public utilities 3,342 281 20 3,603 Sovereign and supranational 2,556 272 14 2,814 Banks/financial institutions 4,932 231 78 5,085 Other corporate 3,000 326 12 3,314 Total yen-denominated 34,242 4,379 124 38,497 Total securities held to maturity $ 34,242 $ 4,379 $ 124 $ 38,497
Investments Classified by Contractual Maturity Date	The contractual maturities of our investments in fixed maturities at December 31, 2015 , were as follows: Aflac Japan Aflac U.S. (In millions) Amortized Fair Amortized Fair Available for sale: Due in one year or less $ 130 $ 142 $ 23 $ 24 Due after one year through five years 2,617 2,984 648 709 Due after five years through 10 years 11,543 11,642 2,105 2,177 Due after 10 years 33,608 37,112 9,049 9,569 Mortgage- and asset-backed securities 372 424 35 43 Total fixed maturities available for sale $ 48,270 $ 52,304 $ 11,860 $ 12,522 Held to maturity: Due in one year or less 316 320 0 0 Due after one year through five years 1,692 1,775 0 0 Due after five years through 10 years 1,613 1,732 0 0 Due after 10 years 29,802 33,655 0 0 Mortgage- and asset-backed securities 36 38 0 0 Total fixed maturities held to maturity $ 33,459 $ 37,520 $ 0 $ 0
Economic Maturities of Investments in Perpetual Securities	The economic maturities of our investments in perpetual securities, which were all reported as available for sale at December 31, 2015 , were as follows: Aflac Japan Aflac U.S. (In millions) Amortized Fair Amortized Fair Due in one year or less $ 301 $ 282 $ 0 $ 0 Due after one year through five years 292 315 0 0 Due after 10 years 1,209 1,293 39 57 Total perpetual securities available for sale $ 1,802 $ 1,890 $ 39 $ 57
Investment Exposures Exceeding 10 Percent Shareholders Equity	Investment exposures that individually exceeded 10% of shareholders' equity as of December 31 were as follows: 2015 2014 (In millions) Credit Amortized Fair Credit Amortized Fair Japan National Government (1) A $36,859 $42,025 A $37,021 $41,878 (1) JGBs or JGB-backed securities
Bank and Financial Institution Investments	Our total investments in the bank and financial institution sector as of December 31 , including those classified as perpetual securities, were as follows: 2015 2014 Total Investments in Percentage of Total Investments in Percentage of Fixed maturities: Amortized cost $ 9,617 10 % $ 10,627 11 % Fair value 10,565 10 11,683 11 Perpetual securities: Upper Tier II: Amortized cost $ 1,217 1 % $ 1,554 2 % Fair value 1,265 1 1,645 1 Tier I: Amortized cost 441 0 703 1 Fair value 477 0 793 1 Total: Amortized cost $ 11,275 11 % $ 12,884 14 % Fair value 12,307 11 14,121 13
Gain (Loss) on Investments	Information regarding pretax realized gains and losses from investments for the years ended December 31 follows: (In millions) 2015 2014 2013 Realized investment gains (losses) on securities: Fixed maturities: Available for sale: Gross gains from sales $ 224 $ 192 $ 316 Gross losses from sales (8 ) (12 ) (87 ) Net gains (losses) from redemptions 52 34 34 Other-than-temporary impairment losses (152 ) (31 ) (128 ) Held to maturity: Net gains (losses) from redemptions 0 1 0 Total fixed maturities 116 184 135 Perpetual securities: Available for sale: Gross losses from sales 0 0 (1 ) Net gains (losses) from redemptions 35 0 0 Other-than-temporary impairment losses 0 0 (70 ) Total perpetual securities 35 0 (71 ) Equity securities: Other-than-temporary impairment losses (1 ) 0 (1 ) Total equity securities (1 ) 0 (1 ) Derivatives and other: Derivative gains (losses) (10 ) 31 326 Other 0 0 10 Total derivatives and other (10 ) 31 336 Total realized investment gains (losses) $ 140 $ 215 $ 399
Other Than Temporary Impairment Losses on Investment Securities	The following table details our pretax other-than-temporary impairment losses by investment category that resulted from our impairment evaluation process for the years ended December 31 . (In millions) 2015 2014 2013 Perpetual securities $ 0 $ 0 $ 70 Corporate bonds 17 31 102 Bank/financial institution bonds 135 0 0 Sovereign and supranational 0 0 26 Equity securities 1 0 1 Total other-than-temporary impairment losses realized (1) $ 153 $ 31 $ 199
Unrealized Gain (Loss) on Investments	Information regarding changes in unrealized gains and losses from investments for the years ended December 31 follows: (In millions) 2015 2014 2013 Changes in unrealized gains (losses): Fixed maturities: Available for sale $ (2,481 ) $ 5,629 $ (2,281 ) Transferred to held to maturity 0 (10 ) (9 ) Perpetual securities: Available for sale (123 ) 269 (129 ) Equity securities 9 5 1 Total change in unrealized gains (losses) $ (2,595 ) $ 5,893 $ (2,418 )
Net Effect on Shareholders' Equity of Unrealized Gains and Losses from Investment Securities	The net effect on shareholders' equity of unrealized gains and losses from investment securities at December 31 was as follows: (In millions) 2015 2014 Unrealized gains (losses) on securities available for sale $ 4,831 $ 7,426 Deferred income taxes (1,845 ) (2,754 ) Shareholders’ equity, unrealized gains (losses) on investment securities $ 2,986 $ 4,672
Investments Gross Unrealized Loss Aging	The following tables show the fair values and gross unrealized losses of our available-for-sale and held-to-maturity investments that were in an unrealized loss position, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at December 31 . 2015 Total Less than 12 months 12 months or longer (In millions) Fair Unrealized Fair Unrealized Fair Unrealized Fixed Maturities: Municipalities: Dollar-denominated $ 80 $ 6 $ 80 $ 6 $ 0 $ 0 Public utilities: Dollar-denominated 2,127 221 1,689 132 438 89 Yen-denominated 1,487 104 1,062 73 425 31 Sovereign and supranational: Yen-denominated 580 26 385 13 195 13 Banks/financial institutions: Dollar-denominated 366 21 348 11 18 10 Yen-denominated 2,350 158 1,147 14 1,203 144 Other corporate: Dollar-denominated 13,430 1,302 11,068 770 2,362 532 Yen-denominated 1,151 77 343 5 808 72 Total fixed maturities 21,571 1,915 16,122 1,024 5,449 891 Perpetual securities: Dollar-denominated 6 1 0 0 6 1 Yen-denominated 645 93 216 12 429 81 Total perpetual securities 651 94 216 12 435 82 Equity securities: Yen-denominated 191 4 191 4 0 0 Total equity securities 191 4 191 4 0 0 Total $ 22,413 $ 2,013 $ 16,529 $ 1,040 $ 5,884 $ 973 2014 Total Less than 12 months 12 months or longer (In millions) Fair Unrealized Fair Unrealized Fair Unrealized Fixed Maturities: Municipalities: Dollar-denominated $ 75 $ 2 $ 53 $ 1 $ 22 $ 1 Public utilities: Dollar-denominated 1,001 36 164 7 837 29 Yen-denominated 805 25 98 1 707 24 Sovereign and supranational: Yen-denominated 359 14 0 0 359 14 Banks/financial institutions: Dollar-denominated 205 8 53 5 152 3 Yen-denominated 1,828 267 166 0 1,662 267 Other corporate: Dollar-denominated 8,072 330 1,901 62 6,171 268 Yen-denominated 1,151 60 122 2 1,029 58 Total fixed maturities 13,496 742 2,557 78 10,939 664 Perpetual securities: Yen-denominated 783 92 194 5 589 87 Total perpetual securities 783 92 194 5 589 87 Total $ 14,279 $ 834 $ 2,751 $ 83 $ 11,528 $ 751
Investments in Unrealized Loss Position	The following table provides more information on our unrealized loss position on fixed maturities and perpetual securities as of December 31. 2015 2014 (In millions) Investments Gross Gross Investments Gross Gross Fixed Maturities: Public utilities 16 % 16 % 93 % 13 % 7 % 100 % Sovereign and supranational 3 1 100 3 2 100 Banks/financial institutions 12 9 59 14 33 31 Other corporate 66 69 86 65 47 88 Total fixed maturities 97 % 95 % 95 % 89 % Perpetual securities 3 5 100 5 11 100 Total 100 % 100 % 100 % 100 %
Securities Lending Transactions Accounted for as Secured Borrowings	Details of our securities lending activities as of December 31 were as follows: Securities Lending Transactions Accounted for as Secured Borrowings 2015 Remaining Contractual Maturity of the Agreements (In millions) Overnight (1) Up to 30 Total Securities lending transactions: Japan government and agencies $ 0 $ 499 $ 499 Public utilities 108 0 108 Banks/financial institutions 13 0 13 Other corporate 321 0 321 Total borrowings $ 442 $ 499 $ 941 Gross amount of recognized liabilities for securities lending transactions $ 941 Amounts related to agreements not included in offsetting disclosure in Note 4 $ 0 (1) These securities are pledged as collateral under our U.S. securities lending program and can be called at our discretion; therefore, they are classified as Overnight and Continuous. Securities Lending Transactions Accounted for as Secured Borrowings 2014 Remaining Contractual Maturity of the Agreements (In millions) Overnight (1) Up to 30 Total Securities lending transactions: Japan government and agencies $ 0 $ 1,720 $ 1,720 Public utilities 80 0 80 Sovereign and supranational 1 0 1 Banks/financial institutions 64 0 64 Other corporate 328 0 328 Total borrowings $ 473 $ 1,720 $ 2,193 Gross amount of recognized liabilities for securities lending transactions $ 2,193 Amounts related to agreements not included in offsetting disclosure in Note 4 $ 0 (1) These securities are pledged as collateral under our U.S. securities lending program and can be called at our discretion; therefore, they are classified as Overnight and Continuous.
Variable Interest Entity, Consolidated
Investments in Variable Interest Entities	The following table presents the cost or amortized cost, fair value and balance sheet caption in which the assets and liabilities of consolidated VIEs are reported as of December 31. Investments in Consolidated Variable Interest Entities 2015 2014 (In millions) Cost or Amortized Fair Cost or Amortized Fair Assets: Fixed maturities, available for sale $ 3,739 $ 4,554 $ 3,020 $ 4,166 Perpetual securities, available for sale 255 228 405 429 Fixed maturities, held to maturity 0 0 83 84 Equity securities 363 363 0 0 Other assets 102 102 106 106 Total assets of consolidated VIEs $ 4,459 $ 5,247 $ 3,614 $ 4,785 Liabilities: Other liabilities $ 293 $ 293 $ 318 $ 318 Total liabilities of consolidated VIEs $ 293 $ 293 $ 318 $ 318
Variable Interest Entity, Not Consolidated
Investments in Variable Interest Entities	The table below reflects the amortized cost, fair value and balance sheet caption in which our investment in VIEs not consolidated are reported as of December 31. Investments in Variable Interest Entities Not Consolidated 2015 2014 (In millions) Amortized Fair Amortized Fair Assets: Fixed maturities, available for sale $ 5,536 $ 6,027 $ 6,104 $ 6,937 Perpetual securities, available for sale 249 253 324 330 Fixed maturities, held to maturity 2,477 2,636 2,564 2,829 Total investments in VIEs not consolidated $ 8,262 $ 8,916 $ 8,992 $ 10,096
Perpetual securities
Schedule of Available-for-sale Securities Reconciliation	Details of our holdings of perpetual securities as of December 31 were as follows: Perpetual Securities 2015 2014 (In millions) Credit Amortized Fair Unrealized Amortized Fair Unrealized Upper Tier II: A $ 31 $ 41 $ 10 $ 61 $ 87 $ 26 BBB 1,023 993 (30 ) 1,330 1,333 3 BB or lower 163 231 68 163 225 62 Total Upper Tier II 1,217 1,265 48 1,554 1,645 91 Tier I: BBB 395 408 13 519 556 37 BB or lower 46 69 23 184 237 53 Total Tier I 441 477 36 703 793 90 Other subordinated BB or lower 183 205 22 183 231 48 Total $ 1,841 $ 1,947 $ 106 $ 2,440 $ 2,669 $ 229

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value and Notional Amount of Derivatives with Counterparty Credit Risk	The counterparties to these derivatives are financial institutions with the following credit ratings as of December 31: 2015 2014 (In millions) Notional Amount Asset Derivatives Liability Derivatives Notional Amount Asset Derivatives Liability Derivatives Counterparties' credit rating: AA $ 2,187 $ 166 $ (35 ) $ 1,098 $ 39 $ (36 ) A 19,940 510 (336 ) 22,564 763 (2,387 ) Total $ 22,127 $ 676 $ (371 ) $ 23,662 $ 802 $ (2,423 )
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	2015 (In millions) Net Derivatives Asset Liability Hedge Designation/ Derivative Type Notional Fair Value Fair Value Fair Value Cash flow hedges: Foreign currency swaps $ 75 $ (15 ) $ 0 $ (15 ) Total cash flow hedges 75 (15 ) 0 (15 ) Fair value hedges: Foreign currency forwards 13,080 45 88 (43 ) Foreign currency options 1,250 0 0 0 Total fair value hedges 14,330 45 88 (43 ) Net investment hedge: Foreign currency forwards 763 13 19 (6 ) Foreign currency options 266 (3 ) 5 (8 ) Total net investment hedge 1,029 10 24 (14 ) Non-qualifying strategies: Foreign currency swaps 6,599 264 563 (299 ) Foreign currency forwards 11 0 0 0 Credit default swaps 83 1 1 0 Total non-qualifying strategies 6,693 265 564 (299 ) Total derivatives $ 22,127 $ 305 $ 676 $ (371 ) Balance Sheet Location Other assets $ 11,413 $ 676 $ 676 $ 0 Other liabilities 10,714 (371 ) 0 (371 ) Total derivatives $ 22,127 $ 305 $ 676 $ (371 ) 2014 (In millions) Net Derivatives Asset Liability Hedge Designation/ Derivative Type Notional Fair Value Fair Value Fair Value Cash flow hedges: Foreign currency swaps $ 75 $ (15 ) $ 0 $ (15 ) Total cash flow hedges 75 (15 ) 0 (15 ) Fair value hedges: Foreign currency forwards 12,388 (1,791 ) 0 (1,791 ) Foreign currency options 697 (32 ) 0 (32 ) Interest rate swaptions 2,502 (159 ) 0 (159 ) Total fair value hedges 15,587 (1,982 ) 0 (1,982 ) Net investment hedge: Foreign currency forwards 1,307 54 56 (2 ) Total net investment hedge 1,307 54 56 (2 ) Non-qualifying strategies: Foreign currency swaps 5,765 443 746 (303 ) Foreign currency forwards 784 (119 ) 0 (119 ) Foreign currency options 53 (1 ) 0 (1 ) Credit default swaps 83 0 0 0 Interest rate swaptions 8 (1 ) 0 (1 ) Total non-qualifying strategies 6,693 322 746 (424 ) Total derivatives $ 23,662 $ (1,621 ) $ 802 $ (2,423 ) Balance Sheet Location Other assets $ 6,531 $ 802 $ 802 $ 0 Other liabilities 17,131 (2,423 ) 0 (2,423 ) Total derivatives $ 23,662 $ (1,621 ) $ 802 $ (2,423 )
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location	The following table presents the gains and losses on derivatives and the related hedged items in fair value hedges for the years ended December 31. Fair Value Hedging Relationships (In millions) Hedging Derivatives Hedged Items Hedging Derivatives Hedged Items Total Gains (Losses) Gains (Losses) Gains (Losses) Ineffectiveness 2015: Foreign currency Fixed-maturity securities $ (133 ) $ (136 ) $ 3 $ (5 ) $ (2 ) Foreign currency Fixed-maturity securities (4 ) 3 (7 ) 7 0 Interest rate Fixed-maturity securities (95 ) 19 (114 ) 99 (15 ) 2014: Foreign currency forwards Fixed-maturity securities $ (1,835 ) $ (38 ) $ (1,797 ) $ 1,819 $ 22 Foreign currency options Fixed-maturity securities (41 ) (4 ) (37 ) 38 1 Interest rate Fixed-maturity securities (318 ) (36 ) (282 ) 316 34 2013: Foreign currency Fixed-maturity securities $ (1,735 ) $ (25 ) $ (1,710 ) $ 1,700 $ (10 ) Interest rate Fixed-maturity securities 17 17 0 0 0
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	The following table summarizes the impact to realized investment gains (losses) and other comprehensive income (loss) from all derivatives and hedging instruments for the years ended December 31. 2015 2014 2013 (In millions) Realized Investment Other (1) Realized Investment Other (1) Realized Other (1) Qualifying hedges: Cash flow hedges: Foreign currency swaps $ 0 $ 0 $ (2 ) $ (17 ) $ (2 ) $ (10 ) Total cash flow hedges 0 0 (2 ) (17 ) (2 ) (10 ) Fair value hedges: Foreign currency forwards (2) (138 ) 0 (16 ) 0 (35 ) 0 Foreign currency options ( 2) 3 0 (3 ) 0 0 0 Interest rate swaptions (2) 4 0 (2 ) 0 17 0 Total fair value hedges (131 ) 0 (21 ) 0 (18 ) 0 Net investment hedge: Non-derivative hedging 0 3 0 39 0 155 Foreign currency swaps 0 0 0 0 0 (104 ) Foreign currency forwards 0 4 0 89 0 24 Foreign currency options 0 0 0 (3 ) 0 4 Total net investment hedge 0 7 0 125 0 79 Non-qualifying strategies: Foreign currency swaps 16 0 151 0 346 0 Foreign currency forwards 100 0 (11 ) 0 0 0 Foreign currency options 0 0 0 0 11 0 Credit default swaps 1 0 3 0 31 0 Interest rate swaps 5 0 (1 ) 0 (8 ) 0 Interest rate swaptions 0 0 1 0 (29 ) 0 Futures (1 ) 0 (89 ) 0 (5 ) 0 Total non- qualifying strategies 121 0 54 0 346 0 Total $ (10 ) $ 7 $ 31 $ 108 $ 326 $ 69 (1) Cash flow hedge items are recorded as unrealized gains (losses) on derivatives and net investment hedge items are recorded in the unrealized foreign currency translation gains (losses) line in the consolidated statement of comprehensive income (loss). (2) Impact shown net of effect of hedged items (see Fair Value Hedges section of this Note 4 for further detail)
Offsetting Assets	Offsetting of Financial Assets and Derivative Assets 2015 Gross Amounts Not Offset (In millions) Gross Amount of Recognized Assets Gross Amount Offset in Balance Sheet Net Amount of Assets Presented in Balance Sheet Carrying Value of Financial Instruments Collateral Received Net Amount Derivative assets: Foreign currency swaps $ 563 $ 0 $ 563 $ 0 $ (313 ) $ 250 Foreign currency forwards 107 0 107 0 (96 ) 11 Foreign currency options 5 0 5 0 (3 ) 2 Credit default swaps 1 0 1 0 0 1 Total derivative assets, subject to a master netting arrangement or offsetting arrangement 676 0 676 0 (412 ) (1) 264 Securities lending and similar arrangements 921 0 921 0 (921 ) 0 Total $ 1,597 $ 0 $ 1,597 $ 0 $ (1,333 ) $ 264 (1) Consists of $86 of pledged securities and $326 of cash. 2014 Gross Amounts Not Offset (In millions) Gross Amount of Recognized Assets Gross Amount Offset in Balance Sheet Net Amount of Assets Presented in Balance Sheet Carrying Value of Financial Instruments Collateral Received Net Amount Derivative assets: Foreign currency swaps $ 746 $ 0 $ 746 $ 0 $ (568 ) $ 178 Foreign currency forwards 56 0 56 0 (51 ) 5 Total derivative assets, subject to a master netting arrangement or offsetting arrangement 802 0 802 0 (619 ) (1) 183 Securities lending and similar arrangements 2,149 0 2,149 0 (2,149 ) 0 Total $ 2,951 $ 0 $ 2,951 $ 0 $ (2,768 ) $ 183 (1) Consists of $153 of pledged securities and $466 of cash.
Offsetting Liabilities	Offsetting of Financial Liabilities and Derivative Liabilities 2015 Gross Amounts Not Offset in Balance Sheet (In millions) Gross Amount of Recognized Liabilities Gross Amount Offset in Balance Sheet Net Amount of Liabilities Presented in Balance Sheet Carrying Value of Financial Instruments Collateral Pledged Net Amount Derivative liabilities: Foreign currency swaps $ (314 ) $ 0 $ (314 ) $ 0 $ 1 $ (313 ) Foreign currency forwards (49 ) 0 (49 ) 0 18 (31 ) Foreign currency options (8 ) 0 (8 ) 0 1 (7 ) Total derivative liabilities, subject to a master netting arrangement or offsetting arrangement (371 ) 0 (371 ) 0 20 (1) (351 ) Securities lending and similar arrangements (941 ) 0 (941 ) 921 0 (20 ) Total $ (1,312 ) $ 0 $ (1,312 ) $ 921 $ 20 $ (371 ) (1) Consists of $17 of pledged securities and $3 of cash. 2014 Gross Amounts Not Offset (In millions) Gross Amount of Recognized Liabilities Gross Amount Offset in Balance Sheet Net Amount of Liabilities Presented in Balance Sheet Carrying Value of Financial Instruments Collateral Pledged Net Amount Derivative liabilities: Foreign currency swaps $ (318 ) $ 0 $ (318 ) $ 0 $ 0 $ (318 ) Foreign currency forwards (1,912 ) 0 (1,912 ) 0 1,439 (473 ) Foreign currency options (33 ) 0 (33 ) 0 24 (9 ) Interest rate swaptions (160 ) 0 (160 ) 0 158 (2 ) Total derivative liabilities, subject to a master netting arrangement or offsetting arrangement (2,423 ) 0 (2,423 ) 0 1,621 (1) (802 ) Securities lending and similar arrangements (2,193 ) 0 (2,193 ) 2,149 0 (44 ) Total $ (4,616 ) $ 0 $ (4,616 ) $ 2,149 $ 1,621 $ (846 ) (1) Consists entirely of pledged securities.

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Hierarchy, Assets and Liabilities Measured on Recurring Basis	The following tables present the fair value hierarchy levels of the Company's assets and liabilities that are measured and carried at fair value on a recurring basis as of December 31. 2015 (In millions) Quoted Prices in Significant Significant Total Assets: Securities available for sale, carried at Fixed maturities: Government and agencies $ 18,669 $ 607 $ 0 $ 19,276 Municipalities 0 1,208 0 1,208 Mortgage- and asset-backed securities 0 362 220 582 Public utilities 0 7,479 0 7,479 Sovereign and supranational 0 1,407 0 1,407 Banks/financial institutions 0 5,993 26 6,019 Other corporate 0 29,378 0 29,378 Total fixed maturities 18,669 46,434 246 65,349 Perpetual securities: Banks/financial institutions 0 1,742 0 1,742 Other corporate 0 205 0 205 Total perpetual securities 0 1,947 0 1,947 Equity securities 489 6 3 498 Other assets: Foreign currency swaps 0 462 101 563 Foreign currency forwards 0 107 0 107 Foreign currency options 0 5 0 5 Credit default swaps 0 0 1 1 Total other assets 0 574 102 676 Other investments 176 0 0 176 Cash and cash equivalents 4,350 0 0 4,350 Total assets $ 23,684 $ 48,961 $ 351 $ 72,996 Liabilities: Foreign currency swaps $ 0 $ 21 $ 293 $ 314 Foreign currency forwards 0 49 0 49 Foreign currency options 0 8 0 8 Total liabilities $ 0 $ 78 $ 293 $ 371 2014 (In millions) Quoted Prices in Significant Significant Total Assets: Securities available for sale, carried at Fixed maturities: Government and agencies $ 18,683 $ 515 $ 0 $ 19,198 Municipalities 0 1,257 0 1,257 Mortgage- and asset-backed securities 0 379 223 602 Public utilities 0 7,897 0 7,897 Sovereign and supranational 0 1,416 0 1,416 Banks/financial institutions 0 6,572 26 6,598 Other corporate 0 28,605 0 28,605 Total fixed maturities 18,683 46,641 249 65,573 Perpetual securities: Banks/financial institutions 0 2,289 149 2,438 Other corporate 0 231 0 231 Total perpetual securities 0 2,520 149 2,669 Equity securities 19 6 3 28 Other assets: Foreign currency swaps 0 640 106 746 Foreign currency forwards 0 56 0 56 Total other assets 0 696 106 802 Other investments 171 0 0 171 Cash and cash equivalents 4,658 0 0 4,658 Total assets $ 23,531 $ 49,863 $ 507 $ 73,901 Liabilities: Foreign currency swaps $ 0 $ 0 $ 318 $ 318 Foreign currency forwards 0 1,912 0 1,912 Foreign currency options 0 33 0 33 Interest rate swaptions 0 160 0 160 Total liabilities $ 0 $ 2,105 $ 318 $ 2,423
Fair Value Hierarchy Levels of Assets and Liabilities Carried at Cost or Amortized Cost	The following tables present the carrying amount and fair value categorized by fair value hierarchy level for the Company's financial instruments that are not carried at fair value as of December 31. 2015 (In millions) Carrying Quoted Prices in Significant Significant Total Assets: Securities held to maturity, Fixed maturities: Government and agencies $ 20,004 $ 23,391 $ 0 $ 0 $ 23,391 Municipalities 341 0 415 0 415 Mortgage and asset-backed 36 0 12 26 38 Public utilities 3,092 0 3,203 0 3,203 Sovereign and 2,555 0 2,711 0 2,711 Banks/financial institutions 4,431 0 4,546 0 4,546 Other corporate 3,000 0 3,216 0 3,216 Other investments 118 0 0 118 118 Total assets $ 33,577 $ 23,391 $ 14,103 $ 144 $ 37,638 Liabilities: Other policyholders’ funds $ 6,285 $ 0 $ 0 $ 6,160 $ 6,160 Notes payable 4,991 0 0 5,285 5,285 Total liabilities $ 11,276 $ 0 $ 0 $ 11,445 $ 11,445 2014 (In millions) Carrying Quoted Prices in Significant Significant Total Assets: Securities held to maturity, Fixed maturities: Government and agencies $ 20,023 $ 23,218 $ 0 $ 0 $ 23,218 Municipalities 346 0 417 0 417 Mortgage and asset-backed 43 0 15 31 46 Public utilities 3,342 0 3,603 0 3,603 Sovereign and 2,556 0 2,814 0 2,814 Banks/financial institutions 4,932 0 5,085 0 5,085 Other corporate 3,000 0 3,314 0 3,314 Total assets $ 34,242 $ 23,218 $ 15,248 $ 31 $ 38,497 Liabilities: Other policyholders’ funds $ 6,031 $ 0 $ 0 $ 5,905 $ 5,905 Notes payable 5,268 0 0 5,835 5,835 Total liabilities $ 11,299 $ 0 $ 0 $ 11,740 $ 11,740
Fair Value Assets Available-for-Sale Securities Primary Pricing Sources	The following tables present the pricing sources for the fair values of our fixed maturities, perpetual securities, and equity securities as of December 31. 2015 (In millions) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Significant Unobservable Inputs Total Securities available for sale, carried at fair value: Fixed maturities: Government and agencies: Third party pricing vendor $ 18,669 $ 607 $ 0 $ 19,276 Total government and agencies 18,669 607 0 19,276 Municipalities: Third party pricing vendor 0 1,208 0 1,208 Total municipalities 0 1,208 0 1,208 Mortgage- and asset-backed securities: Third party pricing vendor 0 362 0 362 Broker/other 0 0 220 220 Total mortgage- and asset-backed securities 0 362 220 582 Public utilities: Third party pricing vendor 0 7,479 0 7,479 Total public utilities 0 7,479 0 7,479 Sovereign and supranational: Third party pricing vendor 0 1,407 0 1,407 Total sovereign and supranational 0 1,407 0 1,407 Banks/financial institutions: Third party pricing vendor 0 5,993 0 5,993 Broker/other 0 0 26 26 Total banks/financial institutions 0 5,993 26 6,019 Other corporate: Third party pricing vendor 0 29,378 0 29,378 Total other corporate 0 29,378 0 29,378 Total fixed maturities 18,669 46,434 246 65,349 Perpetual securities: Banks/financial institutions: Third party pricing vendor 0 1,742 0 1,742 Total banks/financial institutions 0 1,742 0 1,742 Other corporate: Third party pricing vendor 0 205 0 205 Total other corporate 0 205 0 205 Total perpetual securities 0 1,947 0 1,947 Equity securities: Third party pricing vendor 489 6 0 495 Broker/other 0 0 3 3 Total equity securities 489 6 3 498 Total securities available for sale $ 19,158 $ 48,387 $ 249 $ 67,794 2014 (In millions) Quoted Prices in Active Markets Significant Observable Significant Unobservable Inputs Total Securities available for sale, carried at fair value: Fixed maturities: Government and agencies: Third party pricing vendor $ 18,683 $ 515 $ 0 $ 19,198 Total government and agencies 18,683 515 0 19,198 Municipalities: Third party pricing vendor 0 1,257 0 1,257 Total municipalities 0 1,257 0 1,257 Mortgage- and asset-backed securities: Third party pricing vendor 0 379 0 379 Broker/other 0 0 223 223 Total mortgage- and asset-backed securities 0 379 223 602 Public utilities: Third party pricing vendor 0 7,897 0 7,897 Total public utilities 0 7,897 0 7,897 Sovereign and supranational: Third party pricing vendor 0 1,416 0 1,416 Total sovereign and supranational 0 1,416 0 1,416 Banks/financial institutions: Third party pricing vendor 0 6,514 0 6,514 Broker/other 0 58 26 84 Total banks/financial institutions 0 6,572 26 6,598 Other corporate: Third party pricing vendor 0 28,605 0 28,605 Total other corporate 0 28,605 0 28,605 Total fixed maturities 18,683 46,641 249 65,573 Perpetual securities: Banks/financial institutions: Third party pricing vendor 0 2,289 0 2,289 Broker/other 0 0 149 149 Total banks/financial institutions 0 2,289 149 2,438 Other corporate: Third party pricing vendor 0 231 0 231 Total other corporate 0 231 0 231 Total perpetual securities 0 2,520 149 2,669 Equity securities: Third party pricing vendor 19 6 0 25 Broker/other 0 0 3 3 Total equity securities 19 6 3 28 Total securities available for sale $ 18,702 $ 49,167 $ 401 $ 68,270
Fair Value Assets Held-To-Maturity Securities Primary Pricing Sources	2015 (In millions) Quoted Prices in Active Markets for Identical Assets Significant Observable Inputs Significant Unobservable Inputs Total Securities held to maturity, carried at amortized cost: Fixed maturities: Government and agencies: Third party pricing vendor $ 23,391 $ 0 $ 0 $ 23,391 Total government and agencies 23,391 0 0 23,391 Municipalities: Third party pricing vendor 0 415 0 415 Total municipalities 0 415 0 415 Mortgage- and asset-backed securities: Third party pricing vendor 0 12 0 12 Broker/other 0 0 26 26 Total mortgage- and asset-backed securities 0 12 26 38 Public utilities: Third party pricing vendor 0 3,203 0 3,203 Total public utilities 0 3,203 0 3,203 Sovereign and supranational: Third party pricing vendor 0 2,711 0 2,711 Total sovereign and supranational 0 2,711 0 2,711 Banks/financial institutions: Third party pricing vendor 0 4,546 0 4,546 Total banks/financial institutions 0 4,546 0 4,546 Other corporate: Third party pricing vendor 0 3,189 0 3,189 Broker/other 0 27 0 27 Total other corporate 0 3,216 0 3,216 Total securities held to maturity $ 23,391 $ 14,103 $ 26 $ 37,520 2014 (In millions) Quoted Prices in Active Markets Significant Observable Significant Unobservable Inputs Total Securities held to maturity, carried at amortized cost: Fixed maturities: Government and agencies: Third party pricing vendor $ 23,218 $ 0 $ 0 $ 23,218 Total government and agencies 23,218 0 0 23,218 Municipalities: Third party pricing vendor 0 417 0 417 Total municipalities 0 417 0 417 Mortgage- and asset-backed securities: Third party pricing vendor 0 15 0 15 Broker/other 0 0 31 31 Total mortgage- and asset-backed securities 0 15 31 46 Public utilities: Third party pricing vendor 0 3,603 0 3,603 Total public utilities 0 3,603 0 3,603 Sovereign and supranational: Third party pricing vendor 0 2,814 0 2,814 Total sovereign and supranational 0 2,814 0 2,814 Banks/financial institutions: Third party pricing vendor 0 5,085 0 5,085 Total banks/financial institutions 0 5,085 0 5,085 Other corporate: Third party pricing vendor 0 3,287 0 3,287 Broker/other 0 27 0 27 Total other corporate 0 3,314 0 3,314 Total securities held to maturity $ 23,218 $ 15,248 $ 31 $ 38,497
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	The following tables present the changes in fair value of our available-for-sale investments and derivatives classified as Level 3 as of December 31. 2015 Fixed Maturities Perpetual Equity Derivatives (1) (In millions) Mortgage- Public Sovereign Banks/ Other Banks/ Interest Foreign Credit Total Balance, beginning of period $ 223 $ 0 $ 0 $ 26 $ 0 $ 149 $ 3 $ 0 $ (212 ) $ 0 $ 189 Realized investment gains (losses) included 0 0 0 0 0 0 0 0 (15 ) 1 (14 ) Unrealized gains (losses) included in other (1 ) 0 0 0 0 (2 ) 0 0 (1 ) 0 (4 ) Purchases, issuances, sales and settlements: Purchases 0 0 0 0 0 0 0 0 0 0 0 Issuances 0 0 0 0 0 0 0 0 0 0 0 Sales 0 0 0 0 0 (147 ) 0 0 0 0 (147 ) Settlements (2 ) 0 0 0 0 0 0 0 36 0 34 Transfers into Level 3 0 0 0 0 0 0 0 0 0 0 0 Transfers out of Level 3 0 0 0 0 0 0 0 0 0 0 0 Balance, end of period $ 220 $ 0 $ 0 $ 26 $ 0 $ 0 $ 3 $ 0 $ (192 ) $ 1 $ 58 Changes in unrealized gains (losses) relating $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ (15 ) $ 1 $ (14 ) (1) Derivative assets and liabilities are presented net 2014 Fixed Maturities Perpetual Equity Derivatives (1) (In millions) Mortgage- Public Sovereign Banks/ Other Banks/ Interest Foreign Credit Total Balance, beginning of period $ 369 $ 0 $ 0 $ 23 $ 0 $ 52 $ 3 $ 1 $ (99 ) $ (3 ) $ 346 Realized investment gains (losses) included 0 0 0 0 0 0 0 (1 ) (191 ) 3 (189 ) Unrealized gains (losses) included in other (134 ) 0 0 3 0 8 0 0 (17 ) 0 (140 ) Purchases, issuances, sales and settlements: Purchases 0 0 0 0 0 0 0 0 0 0 0 Issuances 0 0 0 0 0 0 0 0 0 0 0 Sales 0 0 0 0 0 (60 ) 0 0 0 0 (60 ) Settlements (12 ) 0 0 0 0 0 0 0 95 0 83 Transfers into Level 3 (2) 0 0 0 0 0 149 0 0 0 0 149 Transfers out of Level 3 0 0 0 0 0 0 0 0 0 0 0 Balance, end of period $ 223 $ 0 $ 0 $ 26 $ 0 $ 149 $ 3 $ 0 $ (212 ) $ 0 $ 189 Changes in unrealized gains (losses) relating $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ (1 ) $ (191 ) $ 3 $ (189 ) (1) Derivative assets and liabilities are presented net (2) Due to use of estimated redemption price
Fair Value Inputs Assets Quantitative Information	The following tables summarize the significant unobservable inputs used in the valuation of our Level 3 available-for-sale investments and derivatives as of December 31. Included in the tables are the inputs or range of possible inputs that have an effect on the overall valuation of the financial instruments. 2015 (In millions) Fair Value Valuation Technique(s) Unobservable Input Range Assets: Securities available for sale, carried at fair value: Fixed maturities: Mortgage- and asset-backed securities $ 220 Consensus pricing Offered quotes N/A (d) Banks/financial institutions 26 Consensus pricing Offered quotes N/A (d) Equity securities 3 Net asset value Offered quotes $1 - $677 ($7) Other assets: Foreign currency swaps 7 Discounted cash flow Interest rates (USD) 2.20% - 2.62% (a) Interest rates (JPY) .42% - 1.22% (b) CDS spreads 32 - 147 bps Foreign exchange rates 20.05% (c) 94 Discounted cash flow Interest rates (USD) 2.20% - 2.62% (a) Interest rates (JPY) .42% - 1.22% (b) Foreign exchange rates 20.05% (c) Credit default swaps 1 Discounted cash flow Base correlation 53.26% - 58.40% (e) CDS spreads 123 bps Recovery rate 36.87% Total assets $ 351 (a) Inputs derived from U.S. long-term rates to accommodate long maturity nature of our swaps (b) Inputs derived from Japan long-term rates to accommodate long maturity nature of our swaps (c) Based on 10 year volatility of JPY/USD exchange rate (d) N/A represents securities where we receive unadjusted broker quotes and for which there is no transparency into the providers' valuation techniques or unobservable inputs. (e) Range of base correlation for our bespoke tranche for attachment and detachment points corresponding to market indices 2014 (In millions) Fair Value Valuation Technique(s) Unobservable Input Range Assets: Securities available for sale, carried at fair value: Fixed maturities: Mortgage- and asset-backed securities $ 223 Consensus pricing Offered quotes N/A (d) Banks/financial institutions 26 Consensus pricing Offered quotes N/A (d) Perpetual securities: Banks/financial institutions 149 Consensus pricing Offered quotes N/A (d) Equity securities 3 Net asset value Offered quotes $1-$677 ($6) Other assets: Foreign currency swaps 8 Discounted cash flow Interest rates (USD) 2.28% - 2.70% (a) Interest rates (JPY) .53% - 1.34% (b) CDS spreads 16 - 105 bps Foreign exchange rates 20.50% (c) 98 Discounted cash flow Interest rates (USD) 2.28% - 2.70% (a) Interest rates (JPY) .53% - 1.34% (b) Foreign exchange rates 20.50% (c) Total assets $ 507 (a) Inputs derived from U.S. long-term rates to accommodate long maturity nature of our swaps (b) Inputs derived from Japan long-term rates to accommodate long maturity nature of our swaps (c) Based on 10 year volatility of JPY/USD exchange rate (d) N/A represents securities where we receive unadjusted broker quotes and for which there is no transparency into the providers' valuation techniques or unobservable inputs.
Fair Value Inputs Liabilities Quantitative Information	2015 (In millions) Fair Value Valuation Technique(s) Unobservable Input Range Liabilities: Foreign currency swaps $ 158 Discounted cash flow Interest rates (USD) 2.20% - 2.62% (a) Interest rates (JPY) .42% - 1.22% (b) CDS spreads 32 - 147 bps Foreign exchange rates 20.05% (c) 120 Discounted cash flow Interest rates (USD) 2.20% - 2.62% (a) Interest rates (JPY) .42% - 1.22% (b) CDS spreads 35 - 213 bps 15 Discounted cash flow Interest rates (USD) 2.20% - 2.62% (a) Interest rates (JPY) .42% - 1.22% (b) Foreign exchange rates 20.05% (c) Total liabilities $ 293 (a) Inputs derived from U.S. long-term rates to accommodate long maturity nature of our swaps (b) Inputs derived from Japan long-term rates to accommodate long maturity nature of our swaps (c) Based on 10 year volatility of JPY/USD exchange rate 2014 (In millions) Fair Value Valuation Technique(s) Unobservable Input Range Liabilities: Foreign currency swaps $ 176 Discounted cash flow Interest rates (USD) 2.28% - 2.70% (a) Interest rates (JPY) .53% - 1.34% (b) CDS spreads 16 - 105 bps Foreign exchange rates 20.50% (c) 111 Discounted cash flow Interest rates (USD) 2.28% - 2.70% (a) Interest rates (JPY) .53% - 1.34% (b) CDS spreads 13 - 145 bps 31 Discounted cash flow Interest rates (USD) 2.28% - 2.70% (a) Interest rates (JPY) .53% - 1.34% (b) Foreign exchange rates 20.50% (c) Total liabilities $ 318 (a) Inputs derived from U.S. long-term rates to accommodate long maturity nature of our swaps (b) Inputs derived from Japan long-term rates to accommodate long maturity nature of our swaps (c) Based on 10 year volatility of JPY/USD exchange rate

DEFERRED POLICY ACQUISITION C33

DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES (Tables)	12 Months Ended
	Dec. 31, 2015
Deferred Policy Acquisition Costs Disclosures [Abstract]
Schedule of Deferred Policy Acquisition Costs	The following table presents a rollforward of deferred policy acquisition costs by segment for the years ended December 31. 2015 2014 (In millions) Japan U.S. Japan U.S. Deferred policy acquisition costs: Balance, beginning of year $ 5,211 $ 3,062 $ 5,819 $ 2,979 Capitalization 738 578 790 548 Amortization (578 ) (488 ) (649 ) (459 ) Foreign currency translation and other (1 ) (11 ) (749 ) (6 ) Balance, end of year $ 5,370 $ 3,141 $ 5,211 $ 3,062
Advertising Expense	Advertising expense, which is included in insurance expenses in the consolidated statements of earnings, was as follows for the years ended December 31: (In millions) 2015 2014 2013 Advertising expense: Aflac Japan $ 82 $ 103 $ 112 Aflac U.S. 129 126 128 Total advertising expense $ 211 $ 229 $ 240
Schedule Of Depreciation And Amortization Expense	Depreciation and other amortization expenses, which are included in insurance expenses in the consolidated statements of earnings, were as follows for the years ended December 31: (In millions) 2015 2014 2013 Depreciation expense $ 44 $ 47 $ 56 Other amortization expense 6 8 13 Total depreciation and other amortization expense $ 50 $ 55 $ 69
Schedule of Lease Expenses	Lease and rental expense, which are included in insurance expenses in the consolidated statements of earnings, were as follows for the years ended December 31: (In millions) 2015 2014 2013 Lease and rental expense: Aflac Japan $ 46 $ 52 $ 55 Aflac U.S. 18 15 10 Other 1 1 1 Total lease and rental expense $ 65 $ 68 $ 66

POLICY LIABILITIES (Tables)

POLICY LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2015
Insurance Loss Reserves [Abstract]
Liability for Future Policy Benefits by Product Segment	The liability for future policy benefits as of December 31 consisted of the following: Liability Amounts Interest Rates (In millions) Policy 2015 2014 Year of In 20 Health insurance: Japan: 1992 - 2015 $ 7,633 $ 3,900 1.25 - 2.5 % 1.25 - 2.5 % 1974 - 2013 1,078 3,449 2.7 - 2.75 2.25 - 2.75 1998 - 2014 11,008 10,641 3.0 3.0 1997 - 1999 2,435 2,461 3.5 3.5 1994 - 1996 2,998 3,023 4.0 - 4.5 4.0 - 4.5 1987 - 1994 14,161 14,394 5.5 5.5 1985 - 1991 1,868 1,923 5.25 - 6.75 5.25 - 5.5 1978 - 1984 2,163 2,260 6.5 5.5 U.S.: 2013 - 2015 57 42 3.0 - 3.5 3.0 - 3.5 2012 - 2015 794 546 3.75 3.75 2011 300 276 4.75 4.75 2005 - 2010 2,986 2,951 5.5 5.5 1988 - 2004 687 706 8.0 6.0 1986 - 2004 1,276 1,293 6.0 6.0 1981 - 1986 174 183 6.5 - 7.0 5.5 - 6.5 1998 - 2004 1,279 1,260 7.0 7.0 Other 21 21 Intercompany eliminations: 2015 (646 ) (1) 0 2.0 2.0 Life insurance: Japan: 2001 - 2015 5,441 3,986 1.5 - 1.85 1.5 - 1.85 2011 - 2015 3,226 2,298 2.0 2.0 2009 - 2011 2,332 1,890 2.25 2.25 1992 - 2006 5 0 2.35 1.77 2005 - 2011 1,330 1,214 2.5 2.5 1985 - 2006 1,962 2,006 2.7 2.25 2007 - 2011 1,105 1,010 2.75 2.75 1999 - 2011 1,988 1,944 3.0 3.0 1996 - 2009 635 633 3.5 3.5 1994 - 1996 877 884 4.0 - 4.5 4.0 - 4.5 U.S.: 1956 - 2015 514 452 3.5 - 6.0 3.5 - 6.0 Total $ 69,687 $ 65,646 (1) Elimination entry necessary due to recapture of a portion of policy liabilities ceded externally, as a result of the reinsurance retrocession transaction as described in Note 8 of the Notes to the Consolidated Financial Statements
Schedule of Liability for Unpaid Claims Adjustment Expense	hanges in the liability for unpaid policy claims were as follows for the years ended December 31: (In millions) 2015 2014 2013 Unpaid supplemental health claims, beginning of year $ 3,412 $ 3,537 $ 3,781 Less reinsurance recoverables 7 9 10 Net balance, beginning of year 3,405 3,528 3,771 Add claims incurred during the year related to: Current year 6,416 6,866 7,215 Prior years (353 ) (301 ) (236 ) Total incurred 6,063 6,565 6,979 Less claims paid during the year on claims incurred during: Current year 4,227 4,532 4,834 Prior years 1,718 1,873 1,931 Total paid 5,945 6,405 6,765 Effect of foreign exchange rate changes on unpaid claims (1 ) (283 ) (457 ) Net balance, end of year 3,522 3,405 3,528 Add reinsurance recoverables 26 7 9 Unpaid supplemental health claims, end of year 3,548 3,412 3,537 Unpaid life claims, end of year 254 218 226 Total liability for unpaid policy claims $ 3,802 $ 3,630 $ 3,763

REINSURANCE (Tables)

REINSURANCE (Tables)	12 Months Ended
	Dec. 31, 2015
Reinsurance Disclosures [Abstract]
Effects of Reinsurance	The following table reconciles direct premium income and direct benefits and claims to net amounts after the effect of reinsurance for the years ended December 31. (In millions) 2015 2014 Direct premium income $ 17,904 $ 19,412 Ceded to other companies: Ceded Aflac Japan closed blocks (481 ) (311 ) Other (39 ) (39 ) Assumed from other companies: Retrocession activities 178 0 Other 8 10 Net premium income $ 17,570 $ 19,072 Direct benefits and claims $ 12,041 $ 13,235 Ceded benefits and change in reserves for future benefits: Ceded Aflac Japan closed blocks (437 ) (276 ) Other 16 (27 ) Assumed from other companies: Retrocession activities 167 0 Other (41 ) 5 Benefits and claims, net $ 11,746 $ 12,937

NOTES PAYABLE (Tables)

NOTES PAYABLE (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	A summary of notes payable as of December 31 follows: (In millions) 2015 2014 3.45% senior notes paid August 2015 $ 0 $ 300 2.65% senior notes due February 2017 652 (1) 653 (1) 8.50% senior notes due May 2019 0 (2) 850 2.40% senior notes due March 2020 550 0 4.00% senior notes due February 2022 350 350 3.625% senior notes due June 2023 700 700 3.625% senior notes due November 2024 749 (3) 749 (3) 3.25% senior notes due March 2025 448 (3) 0 6.90% senior notes due December 2039 397 (3) 397 (3) 6.45% senior notes due August 2040 448 (3) 448 (3) 5.50% subordinated debentures due September 2052 500 500 Yen-denominated Uridashi notes: 2.26% notes due September 2016 (principal amount 8 billion yen) 66 66 Yen-denominated Samurai notes: 1.84% notes due July 2016 (principal amount 15.8 billion yen) 131 131 Yen-denominated loans: 3.60% loan paid July 2015 (principal amount 10 billion yen) 0 83 3.00% loan paid August 2015 (principal amount 5 billion yen) 0 41 Capitalized lease obligations payable through 2022 20 14 Total notes payable $ 5,011 $ 5,282 (1) Principal amount plus an issuance premium that is being amortized over the life of the notes (2) Redeemed in April 2015 (3) Principal amount net of an issuance discount that is being amortized over the life of the notes
Schedule of Maturities of Long Term Debt	The aggregate contractual maturities of notes payable during each of the years after December 31, 2015 , are as follows: (In millions) Long-term Capitalized Total 2016 $ 197 $ 6 $ 203 2017 650 5 655 2018 0 4 4 2019 0 3 3 2020 550 1 551 Thereafter 3,600 1 3,601 Total $ 4,997 $ 20 $ 5,017

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The components of income tax expense (benefit) applicable to pretax earnings for the years ended December 31 were as follows: (In millions) Foreign U.S. Total 2015: Current $ 1,063 $ 225 $ 1,288 Deferred 42 (1 ) 41 Total income tax expense $ 1,105 $ 224 $ 1,329 2014: Current $ 995 $ 84 $ 1,079 Deferred 125 336 461 Total income tax expense $ 1,120 $ 420 $ 1,540 2013: Current $ 934 $ 302 $ 1,236 Deferred 299 123 422 Total income tax expense $ 1,233 $ 425 $ 1,658
Schedule of Effective Income Tax Rate Reconciliation	The principal reasons for the differences and the related tax effects for the years ended December 31 were as follows: (In millions) 2015 2014 2013 Income taxes based on U.S. statutory rates $ 1,352 $ 1,572 $ 1,685 Utilization of foreign tax credit (27 ) (32 ) (37 ) Nondeductible expenses 3 5 6 Other, net 1 (5 ) 4 Income tax expense $ 1,329 $ 1,540 $ 1,658
Schedule of Income Tax Expense Benefit Intraperiod Tax Allocation	Total income tax expense for the years ended December 31 was allocated as follows: (In millions) 2015 2014 2013 Statements of earnings $ 1,329 $ 1,540 $ 1,658 Other comprehensive income (loss): Unrealized foreign currency translation gains (losses) during period 16 (419 ) 253 Unrealized gains (losses) on investment securities: Unrealized holding gains (losses) on investment (931 ) 2,237 (904 ) Reclassification adjustment for realized (gains) losses 21 19 19 Unrealized gains (losses) on derivatives during period 0 (3 ) (4 ) Pension liability adjustment during period (7 ) (31 ) 55 Total income tax expense (benefit) related to items of (901 ) 1,803 (581 ) Additional paid-in capital (exercise of stock options) 4 (7 ) (8 ) Total income taxes $ 432 $ 3,336 $ 1,069
Schedule of Deferred Tax Assets and Liabilities	The income tax effects of the temporary differences that gave rise to deferred income tax assets and liabilities as of December 31 were as follows: (In millions) 2015 2014 Deferred income tax liabilities: Deferred policy acquisition costs $ 2,282 $ 2,209 Unrealized gains on investment securities 1,684 2,584 Premiums receivable 139 139 Policy benefit reserves 1,313 1,376 Depreciation 61 51 Other 0 20 Total deferred income tax liabilities 5,479 6,379 Deferred income tax assets: Other basis differences in investment securities 1,422 1,331 Unfunded retirement benefits 15 16 Other accrued expenses 7 4 Policy and contract claims 113 99 Foreign currency loss on Japan branch 208 327 Deferred compensation 181 226 Capital loss carryforwards 0 26 Other 95 0 Total deferred income tax assets 2,041 2,029 Net deferred income tax liability 3,438 4,350 Current income tax liability 902 943 Total income tax liability $ 4,340 $ 5,293
Summary of Income Tax Contingencies	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows for the years ended December 31: (In millions) 2015 2014 Balance, beginning of year $ 309 $ 328 Additions for tax positions of prior years 0 2 Reductions for tax positions of prior years (45 ) (21 ) Balance, end of year $ 264 $ 309

SHAREHOLDERS' EQUITY (Tables)

SHAREHOLDERS' EQUITY (Tables)	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
Schedule of Common Stock Outstanding Roll Forward	The following table is a reconciliation of the number of shares of the Company's common stock for the years ended December 31. (In thousands of shares) 2015 2014 2013 Common stock - issued: Balance, beginning of period 668,132 667,046 665,239 Exercise of stock options and issuance of restricted shares 1,591 1,086 1,807 Balance, end of period 669,723 668,132 667,046 Treasury stock: Balance, beginning of period 225,687 207,633 197,453 Purchases of treasury stock: Open market 21,179 19,660 13,212 Other 247 157 222 Dispositions of treasury stock: Shares issued to AFL Stock Plan (1,209) (1,251) (1,365) Exercise of stock options (465) (391) (1,734) Other (96) (121) (155) Balance, end of period 245,343 225,687 207,633 Shares outstanding, end of period 424,380 442,445 459,413
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following table presents the approximate number of share-based awards to purchase shares, on a weighted-average basis, that were considered to be anti-dilutive and were excluded from the calculation of diluted earnings per share at December 31: (In thousands) 2015 2014 2013 Anti-dilutive share-based awards 1,862 1,215 2,198
Schedule of Weighted Average Number of Shares	The weighted-average shares used in calculating earnings per share for the years ended December 31 were as follows: (In thousands of shares) 2015 2014 2013 Weighted-average outstanding shares used for calculating basic EPS 430,654 451,204 464,502 Dilutive effect of share-based awards 2,518 2,796 2,906 Weighted-average outstanding shares used for calculating diluted EPS 433,172 454,000 467,408
Changes in Accumulated Other Comprehensive Income (Detail)	The table below is a reconciliation of accumulated other comprehensive income by component for the years ended December 31. Changes in Accumulated Other Comprehensive Income 2015 (In millions) Unrealized Foreign Unrealized Unrealized Pension Total Balance, beginning of period $ (2,541 ) $ 4,672 $ (26 ) $ (126 ) $ 1,979 Other comprehensive 345 (1,646 ) 0 (13 ) (1,314 ) Amounts reclassified from 0 (40 ) 0 0 (40 ) Net current-period other 345 (1,686 ) 0 (13 ) (1,354 ) Balance, end of period $ (2,196 ) $ 2,986 $ (26 ) $ (139 ) $ 625 All amounts in the table above are net of tax. 2014 (In millions) Unrealized Foreign Unrealized Unrealized Pension Liability Adjustment Total Balance, beginning of period $ (1,505 ) $ 1,035 $ (12 ) $ (81 ) $ (563 ) Other comprehensive (1,036 ) 3,672 (14 ) (44 ) 2,578 Amounts reclassified from 0 (35 ) 0 (1 ) (36 ) Net current-period other (1,036 ) 3,637 (14 ) (45 ) 2,542 Balance, end of period $ (2,541 ) $ 4,672 $ (26 ) $ (126 ) $ 1,979 All amounts in the table above are net of tax. 2013 (In millions) Unrealized Foreign Unrealized Unrealized Pension Liability Adjustment Total Balance, beginning of period $ 333 $ 2,570 $ (5 ) $ (183 ) $ 2,715 Other comprehensive (1,833 ) (1,499 ) (7 ) 92 (3,247 ) Amounts reclassified from (5 ) (36 ) 0 10 (31 ) Net current-period other (1,838 ) (1,535 ) (7 ) 102 (3,278 ) Balance, end of period $ (1,505 ) $ 1,035 $ (12 ) $ (81 ) $ (563 ) All amounts in the table above are net of tax.
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]	The table below summarizes the amounts reclassified from each component of accumulated other comprehensive income based on source for the years ended December 31. Reclassifications Out of Accumulated Other Comprehensive Income (In millions) 2015 Details about Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Unrealized gains (losses) on available-for-sale $ 214 Sales and redemptions (153 ) Other-than-temporary impairment 61 Total before tax (21 ) Tax (expense) or benefit (1) $ 40 Net of tax Amortization of defined benefit pension items: Actuarial gains (losses) $ (17 ) Acquisition and operating expenses (2) Prior service (cost) credit 17 Acquisition and operating expenses (2) 0 Tax (expense) or benefit (1) $ 0 Net of tax Total reclassifications for the period $ 40 Net of tax (1) Based on 35% tax rate (2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 14 for additional details). (In millions) 2014 Details about Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Unrealized gains (losses) on available-for-sale $ 57 Sales and redemptions (3 ) Other-than-temporary impairment 54 Total before tax (19 ) Tax (expense) or benefit (1) $ 35 Net of tax Amortization of defined benefit pension items: Actuarial gains (losses) $ (15 ) Acquisition and operating expenses (2) Prior service (cost) credit 17 Acquisition and operating expenses (2) (1 ) Tax (expense) or benefit (1) $ 1 Net of tax Total reclassifications for the period $ 36 Net of tax (1) Based on 35% tax rate (2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 14 for additional details). (In millions) 2013 Details about Accumulated Other Comprehensive Income Components Amount Reclassified from Accumulated Other Comprehensive Income Affected Line Item in the Unrealized foreign currency translation gains $ 7 Sales and redemptions (2 ) Tax (expense) or benefit (1) $ 5 Net of tax Unrealized gains (losses) on available-for-sale $ 255 Sales and redemptions (199 ) Other-than-temporary impairment 56 Total before tax (20 ) Tax (expense) or benefit (1) $ 36 Net of tax Amortization of defined benefit pension items: Actuarial gains (losses) $ (19 ) Acquisition and operating expenses (2) Prior service (cost) credit 4 Acquisition and operating expenses (2) 5 Tax (expense) or benefit (1) $ (10 ) Net of tax Total reclassifications for the period $ 31 Net of tax (1) Based on 35% tax rate (2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 14 for additional details).

SHARE-BASED COMPENSATION (Table

SHARE-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Expense Recognized in Connection with Share Based Awards	The following table presents the impact of the expense recognized in connection with share-based awards for the periods ended December 31. (In millions, except for per-share amounts) 2015 2014 2013 Impact on earnings from continuing operations $ 39 $ 41 $ 37 Impact on earnings before income taxes 39 41 37 Impact on net earnings 27 28 25 Impact on net earnings per share: Basic $ .06 $ .06 $ .05 Diluted .06 .06 .05
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The following table presents the assumptions used in valuing options granted during the years ended December 31. 2015 2014 2013 Expected term (years) 6.3 6.3 6.6 Expected volatility 20.0 % 30.0 % 34.0 % Annual forfeiture rate 2.8 2.7 1.6 Risk-free interest rate 2.0 2.8 1.8 Dividend yield 2.7 2.3 2.6
Schedule of Share-based Compensation, Stock Options, Activity	The following table summarizes stock option activity. (In thousands of shares) Stock Weighted-Average Outstanding at December 31, 2012 12,737 $ 45.00 Granted in 2013 703 52.86 Canceled in 2013 (179 ) 44.79 Exercised in 2013 (3,281 ) 40.52 Outstanding at December 31, 2013 9,980 47.03 Granted in 2014 678 61.81 Canceled in 2014 (115 ) 52.01 Exercised in 2014 (1,236 ) 41.04 Outstanding at December 31, 2014 9,307 48.84 Granted in 2015 855 61.47 Canceled in 2015 (231 ) 55.70 Exercised in 2015 (2,013 ) 45.15 Outstanding at December 31, 2015 7,918 $ 50.94
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable	(In thousands of shares) 2015 2014 2013 Shares exercisable, end of year 6,085 7,497 8,042
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range	The following table summarizes information about stock options outstanding and exercisable at December 31, 2015 . (In thousands of shares) Options Outstanding Options Exercisable Range of Stock Option Wgtd.-Avg. Wgtd.-Avg. Stock Option Wgtd.-Avg. $ 14.99 - $ 43.07 1,651 3.1 $ 34.41 1,651 $ 34.41 43.28 - 48.56 1,727 3.2 47.05 1,723 47.05 49.50 - 57.90 2,066 4.9 54.18 1,608 55.01 58.08 - 61.81 1,628 5.1 61.50 956 61.79 61.84 - 67.67 846 7.8 62.96 147 63.96 $ 14.99 - $ 67.67 7,918 4.5 $ 50.94 6,085 $ 48.45
Schedule of Cash Proceeds Received from Share-based Payment Awards	The following table summarizes stock option activity during the years ended December 31. (In millions) 2015 2014 2013 Total intrinsic value of options exercised $ 36 $ 25 $ 66 Cash received from options exercised 68 39 113 Tax benefit realized as a result of options exercised and 25 17 30
Schedule of Nonvested Restricted Stock Units Activity	The value of restricted stock awards is based on the fair market value of our common stock at the date of grant. The following table summarizes restricted stock activity during the years ended December 31. (In thousands of shares) Shares Weighted-Average Restricted stock at December 31, 2012 1,363 $ 50.19 Granted in 2013 782 52.77 Canceled in 2013 (56 ) 48.63 Vested in 2013 (418 ) 47.49 Restricted stock at December 31, 2013 1,671 52.12 Granted in 2014 584 62.12 Canceled in 2014 (27 ) 52.66 Vested in 2014 (348 ) 56.95 Restricted stock at December 31, 2014 1,880 54.33 Granted in 2015 638 61.51 Canceled in 2015 (145 ) 57.52 Vested in 2015 (558 ) 48.41 Restricted stock at December 31, 2015 1,815 $ 58.42

STATUTORY ACCOUNTING AND DIVI40

STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS (Tables)	12 Months Ended
	Dec. 31, 2015
Insurance [Abstract]
Reconciliation of Capital and Surplus between NAIC and Nebraska state basis	A reconciliation of Aflac's capital and surplus between SAP and practices permitted by the state of Nebraska is shown below: (In millions) 2015 2014 Capital and surplus, Nebraska state basis $ 11,298 $ 10,839 State Permitted Practice: Refundable lease deposits – Japan (38 ) (36 ) Reinsurance - Japan (707 ) 0 Capital and surplus, NAIC basis $ 10,553 $ 10,803
Profits Repatriated Disclosure	Profits repatriated by Aflac Japan to Aflac U.S. were as follows for the years ended December 31: In Dollars In Yen (In millions of dollars and billions of yen) 2015 2014 2013 2015 2014 2013 Profit repatriation $ 2,139 $ 1,704 $ 771 259.0 181.4 76.8

BENEFIT PLANS (Tables)

BENEFIT PLANS (Tables)	12 Months Ended
	Dec. 31, 2015
Schedule of Net Funded Status	Information with respect to our benefit plans' assets and obligations as of December 31 was as follows: Pension Benefits Other Japan U.S. Postretirement Benefits (In millions) 2015 2014 2015 2014 2015 2014 Projected benefit obligation: Benefit obligation, beginning of year $ 267 $ 270 $ 717 $ 601 $ 44 $ 46 Service cost 15 15 23 20 1 1 Interest cost 1 9 18 38 2 2 Actuarial (gain) loss 0 21 (6 ) 74 (5 ) (3 ) Benefits and expenses paid (7 ) (9 ) (17 ) (16 ) (2 ) (2 ) Effect of foreign exchange 0 (39 ) 0 0 0 0 Benefit obligation, end of year 276 267 735 717 40 44 Plan assets: Fair value of plan assets, 183 182 341 313 0 0 Actual return on plan assets 1 12 (6 ) 26 0 0 Employer contributions 21 24 18 18 2 2 Benefits and expenses paid (7 ) (9 ) (17 ) (16 ) (2 ) (2 ) Effect of foreign exchange 0 (26 ) 0 0 0 0 Fair value of plan assets, end of year 198 183 336 341 0 0 Funded status of the plans (1) $ (78 ) $ (84 ) $ (399 ) $ (376 ) $ (40 ) $ (44 ) Amounts recognized in accumulated other Net actuarial (gain) loss $ 42 $ 40 $ 175 $ 167 $ 12 $ 19 Prior service (credit) cost (2 ) (2 ) (4 ) (4 ) (11 ) (28 ) Total included in accumulated $ 40 $ 38 $ 171 $ 163 $ 1 $ (9 ) Accumulated benefit obligation $ 244 $ 235 $ 621 $ 611 N/A (2) N/A (2) (1) Recognized in other liabilities in the consolidated balance sheets (2) Not applicable
Schedule of Assumptions Used	Pension Benefits Other Japan U.S. Postretirement Benefits 2015 2014 2013 2015 2014 2013 2015 2014 2013 Weighted-average actuarial assumptions: Discount rate - net periodic benefit cost 1.75 % 2.25 % 2.25 % 4.50 % 4.75 % 4.25 % 4.50 % 4.75 % 4.25 % Discount rate - benefit obligations 1.75 1.75 2.25 4.50 4.50 4.75 4.50 4.50 4.75 Expected long-term return on plan assets 2.00 2.00 2.00 7.25 7.50 7.50 N/A (1) N/A (1) N/A (1) Rate of compensation increase N/A (1) N/A (1) N/A (1) 4.00 4.00 4.00 N/A (1) N/A (1) N/A (1) Health care cost trend rates N/A (1) N/A (1) N/A (1) N/A (1) N/A (1) N/A (1) 5.30 (2) 5.70 (2) 6.40 (2) (1) Not applicable (2) For the years 2015 , 2014 and 2013 , the health care cost trend rates are expected to trend down to 4.5% in 78 years , 4.6% in 78 years , and 4.6% in 78 years , respectively.
Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates	A one-percentage point increase and decrease in assumed health care cost trend rates would have the following effects as of December 31, 2015 : (In millions) One percentage point increase: Increase in total service and interest costs $ 0 Increase in postretirement benefit obligation 2 One percentage point decrease: Decrease in total service and interest costs $ 0 Decrease in postretirement benefit obligation 2
Schedule of Net Benefit Costs	Pension and other postretirement benefit expenses, included in acquisition and operating expenses in the consolidated statements of earnings for the years ended December 31, included the following components: Pension Benefits Other Japan U.S. Postretirement Benefits (In millions) 2015 2014 2013 2015 2014 2013 2015 2014 2013 Service cost $ 15 $ 15 $ 16 $ 23 $ 20 $ 22 $ 1 $ 1 $ 5 Interest cost 1 9 10 18 38 23 2 2 3 Expected return on plan (4 ) (4 ) (3 ) (22 ) (20 ) (17 ) 0 0 0 Amortization of net actuarial 1 1 2 14 11 15 2 3 2 Amortization of prior service 0 0 0 0 0 0 (17 ) (17 ) (4 ) Net periodic (benefit) cost $ 13 $ 21 $ 25 $ 33 $ 49 $ 43 $ (12 ) $ (11 ) $ 6
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	The following table summarizes the amounts recognized in other comprehensive loss (income) for the years ended December 31: Pension Benefits Other Japan U.S. Postretirement Benefits (In millions) 2015 2014 2013 2015 2014 2013 2015 2014 2013 Net actuarial loss (gain) $ 3 $ 12 $ (14 ) $ 22 $ 67 $ (59 ) $ (5 ) $ (3 ) $ (7 ) Amortization of net actuarial loss (1 ) (1 ) (2 ) (14 ) (11 ) (15 ) (2 ) (3 ) (2 ) Prior service cost (credit) 0 0 0 0 0 (4 ) 0 0 (51 ) Amortization of prior 0 0 0 0 0 0 17 17 4 Total $ 2 $ 11 $ (16 ) $ 8 $ 56 $ (78 ) $ 10 $ 11 $ (56 )
Schedule of Expected Benefit Payments	The following table provides expected benefit payments, which reflect expected future service, as appropriate. Pension Benefits Other (In millions) Japan U.S. Postretirement Benefits 2016 $ 12 $ 21 $ 2 2017 7 22 3 2018 7 23 3 2019 9 24 3 2020 10 25 4 2021-2025 66 170 19
Schedule of Allocation of Plan Assets	Asset allocation targets as of December 31, 2015 were as follows: Japan Pension U.S. Pension Domestic equities 11 % 43 % International equities 15 22 Fixed income securities 59 35 Other 15 0 Total 100 % 100 %
Plan Assets
Fair Value, Assets Measured on Recurring Basis	The following table presents the fair value of Aflac Japan's pension plan assets that are measured at fair value on a recurring basis as of December 31. All of these assets are classified as Level 2 in the fair value hierarchy, except cash and cash equivalents which are classified as Level 1. (In millions) 2015 2014 Japan pension plan assets: Equities: Japanese equity securities $ 22 $ 0 International equity securities 33 34 Fixed income securities: Japanese bonds 71 72 International bonds 48 44 Insurance contracts 23 22 Cash and cash equivalents 1 11 Total $ 198 $ 183 The following table presents the fair value of Aflac U.S.'s pension plan assets that are measured at fair value on a recurring basis as of December 31. All of these assets are classified as Level 1 in the fair value hierarchy. (In millions) 2015 2014 U.S. pension plan assets: Mutual funds: Large cap equity funds $ 94 $ 116 Mid cap equity funds 16 14 Real estate equity funds 10 10 International equity funds 77 61 Fixed income bond funds 134 136 Aflac Incorporated common stock 4 4 Cash and cash equivalents 1 0 Total $ 336 $ 341

COMMITMENTS AND CONTINGENT LI42

COMMITMENTS AND CONTINGENT LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	Future minimum lease payments due under non-cancelable operating leases at December 31, 2015 , were as follows: (In millions) 2016 $ 59 2017 44 2018 31 2019 10 2020 8 Thereafter 20 Total future minimum lease payments $ 172

Unaudited Consolidated Quarte43

Unaudited Consolidated Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	In management's opinion, the following quarterly financial information fairly presents the results of operations for such periods and is prepared on a basis consistent with our annual audited financial statements. (In millions, except for per-share amounts) March 31, June 30, September 30, December 31, Net premium income $ 4,432 $ 4,364 $ 4,380 $ 4,394 Net investment income 782 777 784 792 Realized investment gains (losses) 13 127 (114 ) 114 Other income (loss) (1 ) 19 (10 ) 19 Total revenues 5,226 5,287 5,040 5,319 Total benefits and expenses 4,213 4,413 4,176 4,209 Earnings before income taxes 1,013 874 864 1,110 Total income tax 350 301 297 380 Net earnings $ 663 $ 573 $ 567 $ 730 Net earnings per basic share $ 1.52 $ 1.33 $ 1.32 $ 1.72 Net earnings per diluted share 1.51 1.32 1.32 1.71 Quarterly amounts may not agree in total to the corresponding annual amounts due to rounding. (In millions, except for per-share amounts) March 31, June 30, September 30, December 31, Net premium income $ 4,854 $ 4,888 $ 4,841 $ 4,489 Net investment income 827 843 841 808 Realized investment gains (losses) (46 ) 102 16 143 Other income 5 5 38 74 Total revenues 5,640 5,838 5,736 5,514 Total benefits and expenses 4,536 4,600 4,662 4,439 Earnings before income taxes 1,104 1,238 1,074 1,075 Total income tax 372 428 368 372 Net earnings $ 732 $ 810 $ 706 $ 703 Net earnings per basic share $ 1.61 $ 1.79 $ 1.56 $ 1.57 Net earnings per diluted share 1.60 1.78 1.56 1.57 Quarterly amounts may not agree in total to the corresponding annual amounts due to rounding.

SUMMARY OF SIGNIFICANT ACCOUN44

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Summary of Signficant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Significant Accounting Policies [Line Items]
Income tax expense (benefit) related to items of other comprehensive income (loss)	$ (901)	$ 1,803	$ (581)
Aflac Japan
Significant Accounting Policies [Line Items]
Aflac Japan's percentage of the Company's total revenues	70.00%	72.00%	74.00%
Percentage of the Company assets	83.00%	82.00%
Dollar denominated investment portfolio | Aflac Japan
Significant Accounting Policies [Line Items]
Income tax expense (benefit) related to items of other comprehensive income (loss)			$ 614
Effective income tax rate excluding income tax expense (benefit) related to Aflac Japan's dollar-denominated portfolio			31.00%

BUSINESS SEGMENT AND FOREIGN 45

BUSINESS SEGMENT AND FOREIGN INFORMATION - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)segment	Dec. 31, 2014USD ($)
Segment Reporting Information [Line Items]
Reportable insurance business segments | segment	2
Total receivables related to Aflac Japan's operations	$ 705	$ 842
Aflac Japan
Segment Reporting Information [Line Items]
Total receivables related to Aflac Japan's operations	$ 257	$ 386
Percentage of total receivables related to Aflac Japan's operations	36.40%	45.80%
Maximum | Machinery and equipment
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Useful Life	20 years
Maximum | Building
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Useful Life	50 years
Maximum | Furniture and fixtures
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Useful Life	20 years

BUSINESS SEGMENT AND FOREIGN 46

BUSINESS SEGMENT AND FOREIGN INFORMATION - Operations by Segment - Revenues (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums Earned, Net		$ 4,394	$ 4,380	$ 4,364	$ 4,432	$ 4,489	$ 4,841	$ 4,888	$ 4,854	$ 17,570		$ 19,072	$ 20,135
Net investment income		792	784	777	782	808	841	843	827	3,135		3,319	3,293
Total revenues		$ 5,319	$ 5,040	$ 5,287	$ 5,226	$ 5,514	$ 5,736	$ 5,838	$ 5,640	20,872		22,728	23,939
Other non-operating income (loss)										(35)	[1],[2]	67	28
Realized investment gains (losses), non-operating	[3]									55		171	389
Gain (loss) on change in fair value of derivative, interest rate component, operating										85		44	10
Aflac Japan
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums Earned, Net										12,046		13,861	14,982
Net investment income										2,436		2,662	2,651
Other income (loss)										31		32	55
Total revenues										14,513		16,555	17,688
Aflac Japan | Cancer
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums Earned, Net										4,933		5,596	6,123
Aflac Japan | Medical and other health
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums Earned, Net										3,092		3,770	4,282
Aflac Japan | Life insurance
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums Earned, Net										4,021		4,495	4,577
Aflac U.S.
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums Earned, Net										5,347		5,211	5,153
Net investment income										678		645	632
Other income (loss)										8		3	6
Total revenues										6,033		5,859	5,791
Aflac U.S. | Cancer
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums Earned, Net										1,293		1,279	1,283
Aflac U.S. | Life insurance
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums Earned, Net										268		258	252
Aflac U.S. | Accident and disability
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums Earned, Net										2,391		2,303	2,284
Aflac U.S. | Other health
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums Earned, Net										1,395		1,371	1,334
Other business segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Total revenues										225		43	49
Total Business Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Total revenues										20,771		22,457	23,528
Corporate
Segment Reporting, Revenue Reconciling Item [Line Items]
Total revenues										282		281	302
Intercompany eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Total revenues										(201)		$ (248)	$ (308)
Twenty Fifteen Profit Repatriation
Segment Reporting, Revenue Reconciling Item [Line Items]
Foreign currency transaction gain (loss), realized										$ (20)
[1]	$230 for the make-whole payment associated with the early extinguishment of debt
[2]	Includes a loss of $20 related to the change in value of yen repatriation received in advance of settlement of certain foreign currency derivatives. This loss was offset by derivative gains included in realized investment gains (losses).
[3]	Excluding a gain of $85 in 2015, $44 in 2014 and $10 in 2013 related to the interest rate component of the change in fair value of foreign currency swaps on notes payable which is classified as an operating gain when analyzing segment operations

BUSINESS SEGMENT AND FOREIGN 47

BUSINESS SEGMENT AND FOREIGN INFORMATION - Operations by Segment - Pretax Earnings (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended								12 Months Ended
		Apr. 30, 2015	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Pretax operating earnings											$ 4,073		$ 4,253	$ 4,399
Realized investment gains (losses), non-operating	[1]										55		171	389
Other non-operating income (loss)											(266)	[2],[3]	67	28
Earnings before income taxes			$ 1,110	$ 864	$ 874	$ 1,013	$ 1,075	$ 1,074	$ 1,238	$ 1,104	3,862		4,491	4,816
Income taxes applicable to pretax operating earnings											1,403		1,456	1,512
Effect of foreign currency translation on operating earnings											(198)		(117)	(357)
Gain (loss) on change in fair value of derivative, interest rate component, operating											85		44	10
Aflac Japan
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Pretax operating earnings											3,175		3,458	3,628
Aflac U.S.
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Pretax operating earnings											1,101		1,073	1,038
Other business segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Pretax operating earnings											14		(2)	(1)
Total Business Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Pretax operating earnings											4,290		4,529	4,665
Interest expense, noninsurance operations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Pretax operating earnings											(146)		(198)	(198)
Corporate and eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Pretax operating earnings											(71)		$ (78)	$ (68)
8.50% senior notes due May 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Expense on extinguishment of debt, make-whole premium		$ 230									230
Twenty Fifteen Profit Repatriation
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Foreign currency transaction gain (loss), realized											$ (20)
[1]	Excluding a gain of $85 in 2015, $44 in 2014 and $10 in 2013 related to the interest rate component of the change in fair value of foreign currency swaps on notes payable which is classified as an operating gain when analyzing segment operations
[2]	$230 for the make-whole payment associated with the early extinguishment of debt
[3]	Includes a loss of $20 related to the change in value of yen repatriation received in advance of settlement of certain foreign currency derivatives. This loss was offset by derivative gains included in realized investment gains (losses).

BUSINESS SEGMENT AND FOREIGN 48

BUSINESS SEGMENT AND FOREIGN INFORMATION - Operations by Segment - Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2012
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 118,296	$ 119,767	$ 121,307
Aflac Japan
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	97,646	98,525	102,973
Aflac U.S.
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	18,537	18,383	16,112
Other business segments
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	188	128	155
Total Business Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	116,371	117,036	119,240
Corporate
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	23,415	24,636	19,909
Intercompany eliminations
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ (21,490)	$ (21,905)	$ (17,842)

BUSINESS SEGMENT AND FOREIGN 49

BUSINESS SEGMENT AND FOREIGN INFORMATION - Yen/Dollar Exchange Rates Used (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)¥ / $	Dec. 31, 2014USD ($)¥ / $	Dec. 31, 2013USD ($)¥ / $
Segment Reporting, Other Significant Reconciling Item [Line Items]
Weighted-average yen/dollar exchange rate | ¥ / $	120.99	105.46	97.54
Yen percent strengthening (weakening)	(12.80%)	(7.50%)	(18.20%)
Exchange effect on pretax operating earnings (in millions)	$ (288)	$ (180)	$ (534)
Yen/dollar exchange rate at December 31 | ¥ / $	120.61	120.55
Yen percent strengthening (weakening)	(0.05%)	(12.60%)
Exchange effect on total assets
Segment Reporting, Other Significant Reconciling Item [Line Items]
Exchange effect	$ (36)	$ (10,706)
Exchange effect on total liabilities
Segment Reporting, Other Significant Reconciling Item [Line Items]
Exchange effect	$ (41)	$ (12,025)

BUSINESS SEGMENT AND FOREIGN 50

BUSINESS SEGMENT AND FOREIGN INFORMATION - Information on Transfers of Funds from Aflac Japan (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting [Abstract]
Management fees	$ 53	$ 39	$ 37
Allocated expenses	101	71	74
Profit repatriation	2,139	1,704	771
Total transfers from Aflac Japan	$ 2,293	$ 1,814	$ 882

BUSINESS SEGMENT AND FOREIGN 51

BUSINESS SEGMENT AND FOREIGN INFORMATION - Classes of Property and Equipment (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Property and equipment:
Land	$ 166	$ 168
Buildings	400	393
Equipment	329	305
Total property and equipment	895	866
Less accumulated depreciation	468	437
Net property and equipment	$ 427	$ 429

INVESTMENTS - Components of Net

INVESTMENTS - Components of Net Investment Income (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income									$ 3,230	$ 3,399	$ 3,371
Less investment expenses									95	80	78
Net investment income	$ 792	$ 784	$ 777	$ 782	$ 808	$ 841	$ 843	$ 827	3,135	3,319	3,293
Fixed maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income									3,094	3,249	3,210
Perpetual securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income									114	141	153
Equity securities and other
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income									18	7	7
Short term investments and cash equivalents
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income									$ 4	$ 2	$ 1

INVESTMENTS - Available-For-Sal

INVESTMENTS - Available-For-Sale Investments in Debt Securities, Perpetual Securities and Equity Securities (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	$ 62,963	$ 60,844
Gross Unrealized Gains	6,627	8,136
Gross Unrealized Losses	1,796	710
Fair Value	67,794	68,270
Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	60,642	58,385
Gross Unrealized Gains	6,405	7,806
Gross Unrealized Losses	1,698	618
Fair Value	65,349	65,573
Perpetual securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	1,841	2,440
Gross Unrealized Gains	200	321
Gross Unrealized Losses	94	92
Fair Value	1,947	2,669
Equity securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	480	19
Gross Unrealized Gains	22	9
Gross Unrealized Losses	4	0
Fair Value	498	28
Yen-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	25,592	26,501
Gross Unrealized Gains	3,067	3,029
Gross Unrealized Losses	148	242
Fair Value	28,511	29,288
Yen-denominated | Equity securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	472	10
Gross Unrealized Gains	19	7
Gross Unrealized Losses	4	0
Fair Value	487	17
Dollar-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	35,050	31,884
Gross Unrealized Gains	3,338	4,777
Gross Unrealized Losses	1,550	376
Fair Value	36,838	36,285
Dollar-denominated | Equity securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	8	9
Gross Unrealized Gains	3	2
Gross Unrealized Losses	0	0
Fair Value	11	11
Japan government and agencies | Yen-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	17,293	17,341
Gross Unrealized Gains	1,862	1,740
Gross Unrealized Losses	0	0
Fair Value	19,155	19,081
Municipalities | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Fair Value	1,208	1,257
Municipalities | Yen-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	128	88
Gross Unrealized Gains	9	9
Gross Unrealized Losses	0	0
Fair Value	137	97
Municipalities | Dollar-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	926	961
Gross Unrealized Gains	151	201
Gross Unrealized Losses	6	2
Fair Value	1,071	1,160
Mortgage- and asset-backed securities | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Fair Value	582	602
Mortgage- and asset-backed securities | Yen-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	322	351
Gross Unrealized Gains	33	35
Gross Unrealized Losses	0	0
Fair Value	355	386
Mortgage- and asset-backed securities | Dollar-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	200	185
Gross Unrealized Gains	27	31
Gross Unrealized Losses	0	0
Fair Value	227	216
Public utilities | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Fair Value	7,479	7,897
Public utilities | Yen-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	1,400	1,691
Gross Unrealized Gains	210	226
Gross Unrealized Losses	10	5
Fair Value	1,600	1,912
Public utilities | Dollar-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	5,464	5,061
Gross Unrealized Gains	636	960
Gross Unrealized Losses	221	36
Fair Value	5,879	5,985
Sovereign and supranational | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Fair Value	1,407	1,416
Sovereign and supranational | Yen-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	791	799
Gross Unrealized Gains	180	163
Gross Unrealized Losses	0	0
Fair Value	971	962
Sovereign and supranational | Dollar-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	331	343
Gross Unrealized Gains	105	111
Gross Unrealized Losses	0	0
Fair Value	436	454
Banks/financial institutions | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Fair Value	6,019	6,598
Banks/financial institutions | Perpetual securities
Schedule of Available-for-sale Securities [Line Items]
Fair Value	1,742	2,438
Banks/financial institutions | Yen-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	2,321	2,752
Gross Unrealized Gains	325	325
Gross Unrealized Losses	105	189
Fair Value	2,541	2,888
Banks/financial institutions | Yen-denominated | Perpetual securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	1,581	2,132
Gross Unrealized Gains	143	223
Gross Unrealized Losses	93	92
Fair Value	1,631	2,263
Banks/financial institutions | Dollar-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	2,865	2,943
Gross Unrealized Gains	634	775
Gross Unrealized Losses	21	8
Fair Value	3,478	3,710
Banks/financial institutions | Dollar-denominated | Perpetual securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	77	125
Gross Unrealized Gains	35	50
Gross Unrealized Losses	1	0
Fair Value	111	175
Other corporate | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Fair Value	29,378	28,605
Other corporate | Perpetual securities
Schedule of Available-for-sale Securities [Line Items]
Fair Value	205	231
Other corporate | Yen-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	3,337	3,479
Gross Unrealized Gains	448	531
Gross Unrealized Losses	33	48
Fair Value	3,752	3,962
Other corporate | Yen-denominated | Perpetual securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	183	183
Gross Unrealized Gains	22	48
Gross Unrealized Losses	0	0
Fair Value	205	231
Other corporate | Dollar-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	25,154	22,291
Gross Unrealized Gains	1,774	2,682
Gross Unrealized Losses	1,302	330
Fair Value	25,626	24,643
U.S. Government and Agencies | Dollar-denominated | Fixed maturities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	110	100
Gross Unrealized Gains	11	17
Gross Unrealized Losses	0	0
Fair Value	$ 121	$ 117

INVESTMENTS - Held-to-Maturity

INVESTMENTS - Held-to-Maturity Investments in Debt Securities (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	$ 33,459	$ 34,242
Gross Unrealized Gains	4,278	4,379
Gross Unrealized Losses	217	124
Fair Value	37,520	38,497
Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Fair Value	37,520	38,497
Yen-denominated | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	33,459
Gross Unrealized Gains	4,278	4,379
Gross Unrealized Losses	217	124
Fair Value	37,520	38,497
Japan government and agencies | Yen-denominated | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	20,004
Gross Unrealized Gains	3,387	3,195
Gross Unrealized Losses	0	0
Fair Value	23,391	23,218
Municipalities | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	341	346
Fair Value	415	417
Municipalities | Yen-denominated | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	341
Gross Unrealized Gains	74	71
Gross Unrealized Losses	0	0
Fair Value	415	417
Mortgage- and asset-backed securities | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	36	43
Fair Value	38	46
Mortgage- and asset-backed securities | Yen-denominated | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	36
Gross Unrealized Gains	2	3
Gross Unrealized Losses	0	0
Fair Value	38	46
Public utilities | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	3,092	3,342
Fair Value	3,203	3,603
Public utilities | Yen-denominated | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	3,092
Gross Unrealized Gains	205	281
Gross Unrealized Losses	94	20
Fair Value	3,203	3,603
Sovereign and supranational | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	2,555	2,556
Fair Value	2,711	2,814
Sovereign and supranational | Yen-denominated | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	2,555
Gross Unrealized Gains	182	272
Gross Unrealized Losses	26	14
Fair Value	2,711	2,814
Banks/financial institutions | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	4,431	4,932
Fair Value	4,546	5,085
Banks/financial institutions | Yen-denominated | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	4,431
Gross Unrealized Gains	168	231
Gross Unrealized Losses	53	78
Fair Value	4,546	5,085
Other corporate | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	3,000	3,000
Fair Value	3,216	3,314
Other corporate | Yen-denominated | Fixed maturities
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, fixed maturities, amortized cost	3,000
Gross Unrealized Gains	260	326
Gross Unrealized Losses	44	12
Fair Value	$ 3,216	$ 3,314

INVESTMENTS - Additional Inform

INVESTMENTS - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)investmentissuer	Dec. 31, 2014USD ($)investment	Dec. 31, 2013USD ($)investment
Schedule of Investments [Line Items]
Amortized Cost	$ 62,963	$ 60,844
Reclassified investments from the held-to-maturity portfolio to the available-for-sale portfolio, number of investments | investment	0	3	2
Reclassified investments from the held-to-maturity portfolio to the available-for-sale portfolio, amortized cost		$ 424	$ 492
Reclassified investments from the held-to-maturity portfolio to the available-for-sale portfolio, aggregate unrealized gain (loss)		(54)	$ (153)
Unrealized Gain (Loss)	$ 4,831	7,426
Percentage that the lending policy requires that the fair value of the securities and/or unrestricted cash received as collateral be of the fair value of the loaned securities	102.00%
Fair value of debt securities on deposit with regulatory authorities in the United States and Japan	$ 15
Middle market loan receivable	118
Middle market loan program unfunded amount	53
Middle market loan program commitment	182
Available-for-sale Securities	67,794	68,270
Commercial mortgage loan commitments	10
Variable Interest Entity, Consolidated
Schedule of Investments [Line Items]
Securities available for sale, equity securities, fair value	363	0
Securities available for sale, fixed maturities, amortized cost	3,739	3,020
Securities available for sale, fixed maturities, fair value	4,554	4,166
Available-for-sale securities, fixed maturities, amortized cost	363	0
Variable Interest Entity, Not Consolidated
Schedule of Investments [Line Items]
Securities available for sale, fixed maturities, amortized cost	5,536	6,104
Securities available for sale, fixed maturities, fair value	$ 6,027	6,937
Number of issuers of VIEs not-consolidated | issuer	169
Bank loans
Schedule of Investments [Line Items]
Securities available for sale, fixed maturities, amortized cost	$ 1,400	501
Securities available for sale, fixed maturities, fair value	1,400	579
Perpetual securities
Schedule of Investments [Line Items]
Amortized Cost	1,841	2,440
Unrealized Gain (Loss)	106	229
Available-for-sale Securities	1,947	2,669
Perpetual securities matured or called
Schedule of Investments [Line Items]
Amortized Cost		599
Available-for-sale Securities		$ 630
Parent Company and Other Business Segments
Schedule of Investments [Line Items]
Securities available for sale, fixed maturities, amortized cost	512
Securities available for sale, fixed maturities, fair value	523
Yen-denominated | Publicly traded equity securities
Schedule of Investments [Line Items]
Securities available for sale, equity securities, fair value	$ 485

INVESTMENTS - Contractual Matur

INVESTMENTS - Contractual Maturities of Investments in Fixed Maturities (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Held to maturity:
Total fixed maturities held to maturity, amortized cost	$ 33,459	$ 34,242
Held to maturity:
Total fixed maturities held to maturity, fair value	37,520	$ 38,497
Aflac Japan
Available for sale:
Due in one year or less	130
Due after one year through five years	2,617
Due after five years through 10 years	11,543
Due after 10 years	33,608
Mortgage- and asset-backed securities	372
Total fixed maturities available for sale, amortized cost	48,270
Held to maturity:
Due in one year in less	316
Due after one year through five years	1,692
Due after five years through 10 years	1,613
Due after 10 years	29,802
Mortgage- and asset-backed securities	36
Total fixed maturities held to maturity, amortized cost	33,459
Available for sale:
Due in one year or less	142
Due after one year through five years	2,984
Due after five years through 10 years	11,642
Due after 10 years	37,112
Mortgage- and asset-backed securities	424
Total fixed maturities available for sale, fair value	52,304
Held to maturity:
Due in one year or less	320
Due after one year through five years	1,775
Due after five years through 10 years	1,732
Due after 10 years	33,655
Mortgage- and asset-backed securities	38
Total fixed maturities held to maturity, fair value	37,520
Aflac U.S.
Available for sale:
Due in one year or less	23
Due after one year through five years	648
Due after five years through 10 years	2,105
Due after 10 years	9,049
Mortgage- and asset-backed securities	35
Total fixed maturities available for sale, amortized cost	11,860
Held to maturity:
Due in one year in less	0
Due after one year through five years	0
Due after five years through 10 years	0
Due after 10 years	0
Mortgage- and asset-backed securities	0
Total fixed maturities held to maturity, amortized cost	0
Available for sale:
Due in one year or less	24
Due after one year through five years	709
Due after five years through 10 years	2,177
Due after 10 years	9,569
Mortgage- and asset-backed securities	43
Total fixed maturities available for sale, fair value	12,522
Held to maturity:
Due in one year or less	0
Due after one year through five years	0
Due after five years through 10 years	0
Due after 10 years	0
Mortgage- and asset-backed securities	0
Total fixed maturities held to maturity, fair value	$ 0

INVESTMENTS - Economic Maturiti

INVESTMENTS - Economic Maturities of Investments in Perpetual Securities (Detail) $ in Millions	Dec. 31, 2015USD ($)
Aflac Japan
Investments Classified by Economic Maturity Date [Line Items]
Due in one year or less	$ 301
Due after one year through five years	292
Due after 10 years	1,209
Total perpetual securities available for sale	1,802
Due in one year or less	282
Due after one year through five years	315
Due after 10 years	1,293
Total perpetual securities available for sale	1,890
Aflac U.S.
Investments Classified by Economic Maturity Date [Line Items]
Due in one year or less	0
Due after one year through five years	0
Due after 10 years	39
Total perpetual securities available for sale	39
Due in one year or less	0
Due after one year through five years	0
Due after 10 years	57
Total perpetual securities available for sale	$ 57

INVESTMENTS - Investment Exposu

INVESTMENTS - Investment Exposures Individually Exceeded Ten Percent of Shareholders' Equity (Detail) - Japan National Government - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Summary of Investment Holdings [Line Items]
Credit Rating	A	A
Amortized Cost	$ 36,859	$ 37,021
Fair Value	$ 42,025	$ 41,878

INVESTMENTS - Total Investments

INVESTMENTS - Total Investments in Bank and Financial Institution Sector, Including those Classified as Perpetual Securities (Detail) - Banks/financial institutions - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Summary of Investment Holdings [Line Items]
Amortized Cost	$ 11,275	$ 12,884
Fair Value	$ 12,307	$ 14,121
Percentage of Total Investment Portfolio, Amortized Cost	11.00%	14.00%
Percentage of Total Investment Portfolio, Fair Value	11.00%	13.00%
Fixed maturities
Summary of Investment Holdings [Line Items]
Amortized Cost	$ 9,617	$ 10,627
Fair Value	$ 10,565	$ 11,683
Percentage of Total Investment Portfolio, Amortized Cost	10.00%	11.00%
Percentage of Total Investment Portfolio, Fair Value	10.00%	11.00%
Perpetual securities | Upper Tier II
Summary of Investment Holdings [Line Items]
Amortized Cost	$ 1,217	$ 1,554
Fair Value	$ 1,265	$ 1,645
Percentage of Total Investment Portfolio, Amortized Cost	1.00%	2.00%
Percentage of Total Investment Portfolio, Fair Value	1.00%	1.00%
Perpetual securities | Tier I
Summary of Investment Holdings [Line Items]
Amortized Cost	$ 441	$ 703
Fair Value	$ 477	$ 793
Percentage of Total Investment Portfolio, Amortized Cost	0.00%	1.00%
Percentage of Total Investment Portfolio, Fair Value	0.00%	1.00%

INVESTMENTS - Information Regar

INVESTMENTS - Information Regarding Pretax Realized Gains and Losses From Investments (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses realized	[1]	$ (153)	$ (31)	$ (199)
Derivative gains (losses)		(10)	31	326
Other		0	0	10
Total realized investment gains (losses)		140	215	399
Fixed maturities
Gain (Loss) on Investments [Line Items]
Total realized investment gains (losses)		116	184	135
Perpetual securities
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses realized		0	0	(70)
Total realized investment gains (losses)		35	0	(71)
Equity securities
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses realized		(1)	0	(1)
Total realized investment gains (losses)		(1)	0	(1)
Derivatives and other
Gain (Loss) on Investments [Line Items]
Total realized investment gains (losses)		(10)	31	336
Available-for-sale securities | Fixed maturities
Gain (Loss) on Investments [Line Items]
Gross gains from sales		224	192	316
Gross losses from sales		(8)	(12)	(87)
Net gains (losses) from redemptions		52	34	34
Other-than-temporary impairment losses realized		(152)	(31)	(128)
Available-for-sale securities | Perpetual securities
Gain (Loss) on Investments [Line Items]
Gross losses from sales		0	0	(1)
Net gains (losses) from redemptions		35	0	0
Other-than-temporary impairment losses realized		0	0	(70)
Held-to-maturity Securities | Fixed maturities
Gain (Loss) on Investments [Line Items]
Net gains (losses) from redemptions		$ 0	$ 1	$ 0
[1]	Includes $131 and $45 for the years ended December 31, 2015 and 2013, respectively, for credit-related impairments; $26 for the year ended December 31, 2013 for impairments due to severity and duration of decline in fair value; and $22, $31 and $128 for the years ended December 31, 2015, 2014 and 2013, respectively, from change in intent to sell securities

INVESTMENTS - Pretax Other-Than

INVESTMENTS - Pretax Other-Than-Temporary Impairment Losses by Investment Category (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses	[1]	$ 153	$ 31	$ 199
Credit-related impairment
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses		131		45
Severity and duration of decline in fair value impairment
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses				26
Change in intent impairment
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses		22	31	128
Perpetual securities
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses		0	0	70
Corporate bonds
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses		17	31	102
Banks/financial institutions
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses		135	0	0
Sovereign and supranational
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses		0	0	26
Equity securities
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses		$ 1	$ 0	$ 1
[1]	Includes $131 and $45 for the years ended December 31, 2015 and 2013, respectively, for credit-related impairments; $26 for the year ended December 31, 2013 for impairments due to severity and duration of decline in fair value; and $22, $31 and $128 for the years ended December 31, 2015, 2014 and 2013, respectively, from change in intent to sell securities

INVESTMENTS - Information Reg62

INVESTMENTS - Information Regarding Changes in Unrealized Gains and Losses from Investments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Changes in unrealized gains (losses):
Changes in unrealized gains (losses)	$ (2,595)	$ 5,893	$ (2,418)
Fixed maturities | Available-for-sale securities
Changes in unrealized gains (losses):
Changes in unrealized gains (losses)	(2,481)	5,629	(2,281)
Fixed maturities | Transferred to held to maturity securities
Changes in unrealized gains (losses):
Changes in unrealized gains (losses)	0	(10)	(9)
Perpetual securities | Available-for-sale securities
Changes in unrealized gains (losses):
Changes in unrealized gains (losses)	(123)	269	(129)
Equity securities
Changes in unrealized gains (losses):
Changes in unrealized gains (losses)	$ 9	$ 5	$ 1

INVESTMENTS - Net Effect on Sha

INVESTMENTS - Net Effect on Shareholders' Equity of Unrealized Gains and Losses from Investment Securities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Investments [Abstract]
Unrealized Gain (Losses) on Available-for-sale Securities	$ 4,831	$ 7,426
Deferred income taxes	(1,845)	(2,754)
Shareholders' equity, unrealized gains (losses) on investment securities	$ 2,986	$ 4,672

INVESTMENTS - Fair Value and Gr

INVESTMENTS - Fair Value and Gross Unrealized Losses for Securities That Have Been in Continuous Unrealized Loss Position (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	$ 22,413	$ 14,279
Total Unrealized Losses	2,013	834
Less Than 12 months Fair Value	16,529	2,751
Less Than 12 months Unrealized Losses	1,040	83
12 months or longer Fair Value	5,884	11,528
12 months or longer Unrealized Losses	973	751
Fixed maturities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	21,571	13,496
Total Unrealized Losses	1,915	742
Less Than 12 months Fair Value	16,122	2,557
Less Than 12 months Unrealized Losses	1,024	78
12 months or longer Fair Value	5,449	10,939
12 months or longer Unrealized Losses	891	664
Perpetual securities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	651	783
Total Unrealized Losses	94	92
Less Than 12 months Fair Value	216	194
Less Than 12 months Unrealized Losses	12	5
12 months or longer Fair Value	435	589
12 months or longer Unrealized Losses	82	87
Equity securities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	191
Total Unrealized Losses	4
Less Than 12 months Fair Value	191
Less Than 12 months Unrealized Losses	4
12 months or longer Fair Value	0
12 months or longer Unrealized Losses	0
Dollar-denominated | Fixed maturities | Municipalities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	80	75
Total Unrealized Losses	6	2
Less Than 12 months Fair Value	80	53
Less Than 12 months Unrealized Losses	6	1
12 months or longer Fair Value	0	22
12 months or longer Unrealized Losses	0	1
Dollar-denominated | Fixed maturities | Public utilities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	2,127	1,001
Total Unrealized Losses	221	36
Less Than 12 months Fair Value	1,689	164
Less Than 12 months Unrealized Losses	132	7
12 months or longer Fair Value	438	837
12 months or longer Unrealized Losses	89	29
Dollar-denominated | Fixed maturities | Banks/financial institutions
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	366	205
Total Unrealized Losses	21	8
Less Than 12 months Fair Value	348	53
Less Than 12 months Unrealized Losses	11	5
12 months or longer Fair Value	18	152
12 months or longer Unrealized Losses	10	3
Dollar-denominated | Fixed maturities | Other corporate
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	13,430	8,072
Total Unrealized Losses	1,302	330
Less Than 12 months Fair Value	11,068	1,901
Less Than 12 months Unrealized Losses	770	62
12 months or longer Fair Value	2,362	6,171
12 months or longer Unrealized Losses	532	268
Dollar-denominated | Perpetual securities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	6
Total Unrealized Losses	1
Less Than 12 months Fair Value	0
Less Than 12 months Unrealized Losses	0
12 months or longer Fair Value	6
12 months or longer Unrealized Losses	1
Yen-denominated | Fixed maturities | Public utilities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	1,487	805
Total Unrealized Losses	104	25
Less Than 12 months Fair Value	1,062	98
Less Than 12 months Unrealized Losses	73	1
12 months or longer Fair Value	425	707
12 months or longer Unrealized Losses	31	24
Yen-denominated | Fixed maturities | Sovereign and supranational
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	580	359
Total Unrealized Losses	26	14
Less Than 12 months Fair Value	385	0
Less Than 12 months Unrealized Losses	13	0
12 months or longer Fair Value	195	359
12 months or longer Unrealized Losses	13	14
Yen-denominated | Fixed maturities | Banks/financial institutions
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	2,350	1,828
Total Unrealized Losses	158	267
Less Than 12 months Fair Value	1,147	166
Less Than 12 months Unrealized Losses	14	0
12 months or longer Fair Value	1,203	1,662
12 months or longer Unrealized Losses	144	267
Yen-denominated | Fixed maturities | Other corporate
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	1,151	1,151
Total Unrealized Losses	77	60
Less Than 12 months Fair Value	343	122
Less Than 12 months Unrealized Losses	5	2
12 months or longer Fair Value	808	1,029
12 months or longer Unrealized Losses	72	58
Yen-denominated | Perpetual securities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	645	783
Total Unrealized Losses	93	92
Less Than 12 months Fair Value	216	194
Less Than 12 months Unrealized Losses	12	5
12 months or longer Fair Value	429	589
12 months or longer Unrealized Losses	81	$ 87
Yen-denominated | Equity securities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	191
Total Unrealized Losses	4
Less Than 12 months Fair Value	191
Less Than 12 months Unrealized Losses	4
12 months or longer Fair Value	0
12 months or longer Unrealized Losses	$ 0

INVESTMENTS - Composition of In

INVESTMENTS - Composition of Investments in Unrealized Loss Position (Details)	Dec. 31, 2015	Dec. 31, 2014
Investments, Unrealized Loss Position [Line Items]
Percentage Of Total Investments In Unrealized Loss Position	100.00%	100.00%
Percentage of Total Unrealized Losses	100.00%	100.00%
Fixed maturities
Investments, Unrealized Loss Position [Line Items]
Percentage Of Total Investments In Unrealized Loss Position	97.00%	95.00%
Percentage of Total Unrealized Losses	95.00%	89.00%
Perpetual securities
Investments, Unrealized Loss Position [Line Items]
Percentage Of Total Investments In Unrealized Loss Position	3.00%	5.00%
Percentage of Total Unrealized Losses	5.00%	11.00%
Public utilities | Fixed maturities
Investments, Unrealized Loss Position [Line Items]
Percentage Of Total Investments In Unrealized Loss Position	16.00%	13.00%
Percentage of Total Unrealized Losses	16.00%	7.00%
Sovereign and supranational | Fixed maturities
Investments, Unrealized Loss Position [Line Items]
Percentage Of Total Investments In Unrealized Loss Position	3.00%	3.00%
Percentage of Total Unrealized Losses	1.00%	2.00%
Banks/financial institutions | Fixed maturities
Investments, Unrealized Loss Position [Line Items]
Percentage Of Total Investments In Unrealized Loss Position	12.00%	14.00%
Percentage of Total Unrealized Losses	9.00%	33.00%
Other corporate | Fixed maturities
Investments, Unrealized Loss Position [Line Items]
Percentage Of Total Investments In Unrealized Loss Position	66.00%	65.00%
Percentage of Total Unrealized Losses	69.00%	47.00%
Investment Grade | Perpetual securities
Investments, Unrealized Loss Position [Line Items]
Percentage of unrealized losses attributable to securities that were investment grade	100.00%	100.00%
Investment Grade | Public utilities | Fixed maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of unrealized losses attributable to securities that were investment grade	93.00%	100.00%
Investment Grade | Sovereign and supranational | Fixed maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of unrealized losses attributable to securities that were investment grade	100.00%	100.00%
Investment Grade | Banks/financial institutions | Fixed maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of unrealized losses attributable to securities that were investment grade	59.00%	31.00%
Investment Grade | Other corporate | Fixed maturities
Investments, Unrealized Loss Position [Line Items]
Percentage of unrealized losses attributable to securities that were investment grade	86.00%	88.00%

INVESTMENTS - Details of Holdin

INVESTMENTS - Details of Holdings of Perpetual Securities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Investment Holdings [Line Items]
Amortized Cost	$ 62,963	$ 60,844
Fair Value	67,794	68,270
Unrealized Gain (Loss)	4,831	7,426
Perpetual securities
Investment Holdings [Line Items]
Amortized Cost	1,841	2,440
Fair Value	1,947	2,669
Unrealized Gain (Loss)	106	229
Upper Tier II | Perpetual securities
Investment Holdings [Line Items]
Amortized Cost	1,217	1,554
Fair Value	1,265	1,645
Unrealized Gain (Loss)	48	91
Upper Tier II | A | Perpetual securities
Investment Holdings [Line Items]
Amortized Cost	31	61
Fair Value	41	87
Unrealized Gain (Loss)	10	26
Upper Tier II | BBB | Perpetual securities
Investment Holdings [Line Items]
Amortized Cost	1,023	1,330
Fair Value	993	1,333
Unrealized Gain (Loss)	(30)	3
Upper Tier II | BB or Lower | Perpetual securities
Investment Holdings [Line Items]
Amortized Cost	163	163
Fair Value	231	225
Unrealized Gain (Loss)	68	62
Tier I | Perpetual securities
Investment Holdings [Line Items]
Amortized Cost	441	703
Fair Value	477	793
Unrealized Gain (Loss)	36	90
Tier I | BBB | Perpetual securities
Investment Holdings [Line Items]
Amortized Cost	395	519
Fair Value	408	556
Unrealized Gain (Loss)	13	37
Tier I | BB or Lower | Perpetual securities
Investment Holdings [Line Items]
Amortized Cost	46	184
Fair Value	69	237
Unrealized Gain (Loss)	23	53
Other subordinated - non-banks | BB or Lower | Perpetual securities
Investment Holdings [Line Items]
Amortized Cost	183	183
Fair Value	205	231
Unrealized Gain (Loss)	$ 22	$ 48

INVESTMENTS - Investments in Co

INVESTMENTS - Investments in Consolidated Variable Interest Entities (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Securities held to maturity, fixed maturities, amortized cost	$ 33,459	$ 34,242
Securities held to maturity, fixed maturities, fair value	37,520	38,497
Asset derivatives	676	802
Assets, fair value	72,996	73,901
Liability derivatives	371	2,423
Liabilities	100,588	101,420
Liabilities, fair value disclosure	371	2,423
Variable Interest Entity, Consolidated
Variable Interest Entity [Line Items]
Securities available for sale, fixed maturities, amortized cost	3,739	3,020
Securities available for sale, fixed maturities, fair value	4,554	4,166
Securities available for sale, perpetual securities, amortized cost	255	405
Securities available for sale, perpetual securities, fair value	228	429
Securities held to maturity, fixed maturities, amortized cost	0	83
Securities held to maturity, fixed maturities, fair value	0	84
Securities available for sale, equity securities, cost	363	0
Securities available for sale, equity securities, fair value	363	0
Asset derivatives, amortized cost	102	106
Asset derivatives	102	106
Assets, amortized cost	4,459	3,614
Assets, fair value	5,247	4,785
Liability derivatives, amortized cost	293	318
Liability derivatives	293	318
Liabilities	293	318
Liabilities, fair value disclosure	$ 293	$ 318

INVESTMENTS - Investments in Va

INVESTMENTS - Investments in Variable Interest Entities Not Consolidated (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Securities held to maturity, fixed maturities, amortized cost	$ 33,459	$ 34,242
Securities held to maturity, fixed maturities, fair value	37,520	38,497
Assets, fair value	72,996	73,901
Variable Interest Entity, Not Consolidated
Variable Interest Entity [Line Items]
Securities available for sale, fixed maturities, amortized cost	5,536	6,104
Securities available for sale, fixed maturities, fair value	6,027	6,937
Securities available for sale, perpetual securities, amortized cost	249	324
Securities available for sale, perpetual securities, fair value	253	330
Securities held to maturity, fixed maturities, amortized cost	2,477	2,564
Securities held to maturity, fixed maturities, fair value	2,636	2,829
Assets, amortized cost	8,262	8,992
Assets, fair value	$ 8,916	$ 10,096

INVESTMENTS - Securities Lendin

INVESTMENTS - Securities Lending Accounted for as Secured Borrowings (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions		$ 941	$ 2,193
Gross amount of recognized liabilities for securities lending		941	2,193
Amounts related to agreements not included in offsetting disclosure in Note 4		0	0
Japan government and agencies
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions		499	1,720
Public utilities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions		108	80
Sovereign and supranational
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions			1
Banks/financial institutions
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions		13	64
Other corporate
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions		321	328
Maturity Overnight and Continuous
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions	[1]	442	473
Maturity Overnight and Continuous | Japan government and agencies
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions	[1]	0	0
Maturity Overnight and Continuous | Public utilities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions	[1]	108	80
Maturity Overnight and Continuous | Sovereign and supranational
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions	[1]		1
Maturity Overnight and Continuous | Banks/financial institutions
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions	[1]	13	64
Maturity Overnight and Continuous | Other corporate
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions	[1]	321	328
Maturity up to 30 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions		499	1,720
Maturity up to 30 Days | Japan government and agencies
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions		499	1,720
Maturity up to 30 Days | Public utilities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions		0	0
Maturity up to 30 Days | Sovereign and supranational
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions			0
Maturity up to 30 Days | Banks/financial institutions
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions		0	0
Maturity up to 30 Days | Other corporate
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending transactions		$ 0	$ 0
[1]	These securities are pledged as collateral under our U.S. securities lending program and can be called at our discretion; therefore, they are classified as Overnight and Continuous.

DERIVATIVE INSTRUMENTS - Additi

DERIVATIVE INSTRUMENTS - Additional Information (Detail) ¥ in Billions	12 Months Ended
	Dec. 31, 2015USD ($)yrcounterpartiescurrency	Dec. 31, 2014USD ($)		Dec. 31, 2013USD ($)	Dec. 31, 2015JPY (¥)yrcounterpartiescurrency	Mar. 31, 2015USD ($)	Nov. 30, 2014USD ($)	Jun. 30, 2013USD ($)	Oct. 31, 2012USD ($)	Sep. 30, 2012USD ($)	Jul. 31, 2012USD ($)	Feb. 29, 2012USD ($)
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Number of currencies related to foreign currency swaps | currency	1				1
Number of counterparties | counterparties	15				15
Number of counterparties that comprise majority of aggregate notional amount of swaps | counterparties	5				5
Percentage of notional amount of swaps from certain number of counterparties	63.00%				63.00%
Collateral Already Posted, Aggregate Fair Value	$ 20,000,000	$ 1,600,000,000
Derivative, Collateral, Right to Reclaim Securities	17,000,000	1,621,000,000	[1]
Derivative, Collateral, Right to Reclaim Cash	3,000,000
Derivative, Net Liability Position, Aggregate Fair Value	26,000,000	2,100,000,000
Additional Collateral, Aggregate Fair Value	6,000,000
Collateral obtained from third parties	$ 412,000,000	619,000,000
Hedging activity, weighted-average period (in years) | yr	10				10
Net Derivatives Notional Amount	$ 22,127,000,000	23,662,000,000
Cash flow hedges
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Net Derivatives Notional Amount	75,000,000	75,000,000
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	0		$ 0
Net investment hedge
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Net Derivatives Notional Amount	1,029,000,000	1,307,000,000
3.625% senior notes due November 2024
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Debt instrument, principal amount	750,000,000						$ 750,000,000
Debt instrument, effective interest rate							1.00%
3.25% senior notes due March 2025
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Debt instrument, principal amount	450,000,000					$ 450,000,000
Debt instrument, effective interest rate						0.82%
3.625% senior notes due June 2023
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Debt instrument, principal amount	700,000,000							$ 700,000,000
Debt instrument, effective interest rate								1.50%
2.65% senior notes due February 2017
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Debt instrument, principal amount	400,000,000										$ 250,000,000	$ 400,000,000
Debt instrument, effective interest rate												1.22%
2.40% senior notes due March 2020
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Debt instrument, principal amount	550,000,000					$ 550,000,000
Debt instrument, effective interest rate						0.24%
4.00% senior notes due February 2022
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Debt instrument, principal amount	350,000,000											$ 350,000,000
Debt instrument, effective interest rate												2.07%
5.50% subordinated notes due September 2052
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Debt instrument, principal amount	500,000,000								$ 50,000,000	$ 450,000,000
Debt instrument, effective interest rate									4.42%	4.41%
February twenty fifteen profit repatriation | Foreign currency forwards and options
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Net Derivatives Notional Amount | ¥					¥ 30
July twenty fifteen profit repatriation | Foreign currency forwards and options
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Net Derivatives Notional Amount | ¥					102.5
September twenty fifteen profit repatriation | Foreign currency forwards and options
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Net Derivatives Notional Amount | ¥					25
December Twenty Fifteen Profit Repatriation [Domain] | Foreign currency forwards and options
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Net Derivatives Notional Amount | ¥					85
Future profit repatriation | Foreign currency forwards and options
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Net Derivatives Notional Amount | ¥					¥ 124.1
Net investment hedge
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Net investment hedge gain loss reclassified to earnings net	$ 0	$ 0		$ 0
[1]	Consists entirely of pledged securities.

DERIVATIVE INSTRUMENTS - Fair V

DERIVATIVE INSTRUMENTS - Fair Value and Notional Amounts of Derivatives With Counterparty Credit Risk (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Net Derivatives Notional Amount	$ 22,127	$ 23,662
Assets Derivatives Fair Value	676	802
Liability Derivatives Fair Value	(371)	(2,423)
AA
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Net Derivatives Notional Amount	2,187	1,098
Assets Derivatives Fair Value	166	39
Liability Derivatives Fair Value	(35)	(36)
A
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Net Derivatives Notional Amount	19,940	22,564
Assets Derivatives Fair Value	510	763
Liability Derivatives Fair Value	$ (336)	$ (2,387)

DERIVATIVE INSTRUMENTS - Summar

DERIVATIVE INSTRUMENTS - Summary of Balance Sheet Classification of Derivative Fair Value Amounts, as well as Gross Asset and Liability Fair Value Amounts (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	$ 22,127	$ 23,662
Net Derivatives Fair Value	305	(1,621)
Asset Derivatives Fair Value	676	802
Liability Derivatives Fair Value	(371)	(2,423)
Other assets
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	11,413	6,531
Net Derivatives Fair Value	676	802
Asset Derivatives Fair Value	676	802
Liability Derivatives Fair Value	0	0
Other Liabilities
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	10,714	17,131
Net Derivatives Fair Value	(371)	(2,423)
Asset Derivatives Fair Value	0	0
Liability Derivatives Fair Value	(371)	(2,423)
Foreign currency swaps
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	563	746
Liability Derivatives Fair Value	(314)	(318)
Foreign currency forwards
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	107	56
Liability Derivatives Fair Value	(49)	(1,912)
Foreign currency options
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	5
Liability Derivatives Fair Value	(8)	(33)
Credit default swaps
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	1
Interest rate swaptions
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value		(160)
Cash flow hedges
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	75	75
Net Derivatives Fair Value	(15)	(15)
Asset Derivatives Fair Value	0	0
Liability Derivatives Fair Value	(15)	(15)
Cash flow hedges | Foreign currency swaps
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	75	75
Net Derivatives Fair Value	(15)	(15)
Asset Derivatives Fair Value	0	0
Liability Derivatives Fair Value	(15)	(15)
Fair value hedges
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	14,330	15,587
Net Derivatives Fair Value	45	(1,982)
Asset Derivatives Fair Value	88	0
Liability Derivatives Fair Value	(43)	(1,982)
Fair value hedges | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	13,080	12,388
Net Derivatives Fair Value	45	(1,791)
Asset Derivatives Fair Value	88	0
Liability Derivatives Fair Value	(43)	(1,791)
Fair value hedges | Foreign currency options
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	1,250	697
Net Derivatives Fair Value	0	(32)
Asset Derivatives Fair Value	0	0
Liability Derivatives Fair Value	0	(32)
Fair value hedges | Interest rate swaptions
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount		2,502
Net Derivatives Fair Value		(159)
Asset Derivatives Fair Value		0
Liability Derivatives Fair Value		(159)
Net investment hedge
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	1,029	1,307
Net Derivatives Fair Value	10	54
Asset Derivatives Fair Value	24	56
Liability Derivatives Fair Value	(14)	(2)
Net investment hedge | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	763	1,307
Net Derivatives Fair Value	13	54
Asset Derivatives Fair Value	19	56
Liability Derivatives Fair Value	(6)	(2)
Net investment hedge | Foreign currency options
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	266
Net Derivatives Fair Value	(3)
Asset Derivatives Fair Value	5
Liability Derivatives Fair Value	(8)
Non-qualifying strategies
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	6,693	6,693
Net Derivatives Fair Value	265	322
Asset Derivatives Fair Value	564	746
Liability Derivatives Fair Value	(299)	(424)
Non-qualifying strategies | Foreign currency swaps
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	6,599	5,765
Net Derivatives Fair Value	264	443
Asset Derivatives Fair Value	563	746
Liability Derivatives Fair Value	(299)	(303)
Non-qualifying strategies | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	11	784
Net Derivatives Fair Value	0	(119)
Asset Derivatives Fair Value	0	0
Liability Derivatives Fair Value	0	(119)
Non-qualifying strategies | Foreign currency options
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount		53
Net Derivatives Fair Value		(1)
Asset Derivatives Fair Value		0
Liability Derivatives Fair Value		(1)
Non-qualifying strategies | Credit default swaps
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount	83	83
Net Derivatives Fair Value	1	0
Asset Derivatives Fair Value	1	0
Liability Derivatives Fair Value	$ 0	0
Non-qualifying strategies | Interest rate swaptions
Derivatives, Fair Value [Line Items]
Net Derivatives Notional Amount		8
Net Derivatives Fair Value		(1)
Asset Derivatives Fair Value		0
Liability Derivatives Fair Value		$ (1)

DERIVATIVE INSTRUMENTS - Gains

DERIVATIVE INSTRUMENTS - Gains (Losses) Recognized on Fair Value Hedging Relationships (Details) - Fixed maturities - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Foreign currency forwards
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) recognized for derivatives	$ (133)	$ (1,835)	$ (1,735)
Gains (losses) on derivatives excluded from effectiveness testing	(136)	(38)	(25)
Gains (losses) on derivatives included in effectiveness testing	3	(1,797)	(1,710)
Gains (losses) recognized for hedged items	(5)	1,819	1,700
Ineffectiveness recognized for fair value hedge	(2)	22	(10)
Foreign currency options
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) recognized for derivatives	(4)	(41)
Gains (losses) on derivatives excluded from effectiveness testing	3	(4)
Gains (losses) on derivatives included in effectiveness testing	(7)	(37)
Gains (losses) recognized for hedged items	7	38
Ineffectiveness recognized for fair value hedge	0	1
Interest rate swaptions
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) recognized for derivatives	(95)	(318)	17
Gains (losses) on derivatives excluded from effectiveness testing	19	(36)	17
Gains (losses) on derivatives included in effectiveness testing	(114)	(282)	0
Gains (losses) recognized for hedged items	99	316	0
Ineffectiveness recognized for fair value hedge	$ (15)	$ 34	$ 0

DERIVATIVE INSTRUMENTS - Deriva

DERIVATIVE INSTRUMENTS - Derivatives and Hedging Instruments Gain (Loss) Summary (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized foreign currency translation gains (losses) during period		$ 360	$ (1,455)	$ (1,588)
Derivative and other gains (losses)		(10)	31	326
Derivative and non-derivative hedging instruments gain loss recognized in other comprehensive income effective portion before tax	[1]	7	108	69
Cash flow hedges
Derivative Instruments, Gain (Loss) [Line Items]
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)		0	(2)	(2)
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1]	0	(17)	(10)
Cash flow hedges | Foreign currency swaps
Derivative Instruments, Gain (Loss) [Line Items]
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)		0	(2)	(2)
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1]	0	(17)	(10)
Fair value hedges
Derivative Instruments, Gain (Loss) [Line Items]
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)		(131)	(21)	(18)
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1]	0	0	0
Fair value hedges | Foreign currency forwards
Derivative Instruments, Gain (Loss) [Line Items]
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)	[2]	(138)	(16)	(35)
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1],[2]	0	0	0
Fair value hedges | Foreign currency options
Derivative Instruments, Gain (Loss) [Line Items]
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)	[2]	3	(3)	0
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1],[2]	0	0	0
Fair value hedges | Interest rate swaptions
Derivative Instruments, Gain (Loss) [Line Items]
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)	[2]	4	(2)	17
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1],[2]	0	0	0
Net investment hedge
Derivative Instruments, Gain (Loss) [Line Items]
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)		0	0	0
Unrealized foreign currency translation gains (losses) during period	[1]	7	125	79
Net investment hedge | Foreign currency swaps
Derivative Instruments, Gain (Loss) [Line Items]
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)		0	0	0
Unrealized foreign currency translation gains (losses) during period	[1]	0	0	(104)
Net investment hedge | Foreign currency forwards
Derivative Instruments, Gain (Loss) [Line Items]
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)		0	0	0
Unrealized foreign currency translation gains (losses) during period	[1]	4	89	24
Net investment hedge | Foreign currency options
Derivative Instruments, Gain (Loss) [Line Items]
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)		0	0	0
Unrealized foreign currency translation gains (losses) during period	[1]	0	(3)	4
Net investment hedge | Non-derivative hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion)		0	0	0
Unrealized foreign currency translation gains (losses) during period	[1]	3	39	155
Non-qualifying strategies
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) Recognized in Income, Net		121	54	346
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1]	0	0	0
Non-qualifying strategies | Foreign currency swaps
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) Recognized in Income, Net		16	151	346
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1]	0	0	0
Non-qualifying strategies | Foreign currency forwards
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) Recognized in Income, Net		100	(11)	0
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1]	0	0	0
Non-qualifying strategies | Foreign currency options
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) Recognized in Income, Net		0	0	11
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1]	0	0	0
Non-qualifying strategies | Interest rate swaptions
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) Recognized in Income, Net		0	1	(29)
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1]	0	0	0
Non-qualifying strategies | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) Recognized in Income, Net		5	(1)	(8)
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1]	0	0	0
Non-qualifying strategies | Credit default swaps
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) Recognized in Income, Net		1	3	31
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1]	0	0	0
Non-qualifying strategies | Futures
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instrument, Gain (Loss) Recognized in Income, Net		(1)	(89)	(5)
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion)	[1]	$ 0	$ 0	$ 0
[1]	Cash flow hedge items are recorded as unrealized gains (losses) on derivatives and net investment hedge items are recorded in the unrealized foreign currency translation gains (losses) line in the consolidated statement of comprehensive income (loss).
[2]	Impact shown net of effect of hedged items (see Fair Value Hedges section of this Note 4 for further detail)

DERIVATIVE INSTRUMENTS - Offset

DERIVATIVE INSTRUMENTS - Offsetting of Financial Assets and Derivative Assets (Details) - USD ($) $ in Millions	Dec. 31, 2015		Dec. 31, 2014
Offsetting Assets [Line Items]
Gross amount of recognized derivative assets	$ 676		$ 802
Gross amount of liabilities offset in balance sheet	0		0
Net amount of derivative assets presented in balance sheet	676		802
Financial instruments, amount not offset against derivative assets in balance sheet	0		0
Derivative, Collateral, Obligation to Return Cash and Securities	(412)	[1]	(619)	[2]
Derivative asset, fair value, amount offset against collateral	264		183
Derivative, Collateral, Obligation to Return Securities	(86)		(153)
Derivative, Collateral, Obligation to Return Cash	(326)		(466)
Foreign currency swaps
Offsetting Assets [Line Items]
Gross amount of recognized derivative assets	563		746
Gross amount of liabilities offset in balance sheet	0		0
Net amount of derivative assets presented in balance sheet	563		746
Financial instruments, amount not offset against derivative assets in balance sheet	0		0
Derivative, Collateral, Obligation to Return Cash and Securities	(313)		(568)
Derivative asset, fair value, amount offset against collateral	250		178
Foreign currency forwards
Offsetting Assets [Line Items]
Gross amount of recognized derivative assets	107		56
Gross amount of liabilities offset in balance sheet	0		0
Net amount of derivative assets presented in balance sheet	107		56
Financial instruments, amount not offset against derivative assets in balance sheet	0		0
Derivative, Collateral, Obligation to Return Cash and Securities	(96)		(51)
Derivative asset, fair value, amount offset against collateral	11		5
Foreign currency options
Offsetting Assets [Line Items]
Gross amount of recognized derivative assets	5
Gross amount of liabilities offset in balance sheet	0
Net amount of derivative assets presented in balance sheet	5
Financial instruments, amount not offset against derivative assets in balance sheet	0
Derivative, Collateral, Obligation to Return Cash and Securities	(3)
Derivative asset, fair value, amount offset against collateral	2
Credit default swaps
Offsetting Assets [Line Items]
Gross amount of recognized derivative assets	1
Gross amount of liabilities offset in balance sheet	0
Net amount of derivative assets presented in balance sheet	1
Financial instruments, amount not offset against derivative assets in balance sheet	0
Derivative, Collateral, Obligation to Return Cash and Securities	0
Derivative asset, fair value, amount offset against collateral	1
Offsetting assets
Offsetting Assets [Line Items]
Gross amounts of recognized financial instruments	1,597		2,951
Gross amounts offset in balance sheet	0		0
Net amounts of financial instruments presented in balance sheet	1,597		2,951
Carrying value of financial instruments not offset in balance sheet	0		0
Collateral not offset in balance sheet	(1,333)		(2,768)
Financial instruments, amount offset against collateral	264		183
Offsetting assets | Securities lending and similar arrangements
Offsetting Assets [Line Items]
Gross amounts of recognized financial instruments	921		2,149
Gross amounts offset in balance sheet	0		0
Net amounts of financial instruments presented in balance sheet	921		2,149
Carrying value of financial instruments not offset in balance sheet	0		0
Collateral not offset in balance sheet	(921)		(2,149)
Financial instruments, amount offset against collateral	$ 0		$ 0
[1]	Consists of $86 of pledged securities and $326 of cash.
[2]	Consists of $153 of pledged securities and $466 of cash.

DERIVATIVE INSTRUMENTS - Offs76

DERIVATIVE INSTRUMENTS - Offsetting of Financial Liabilities and Derivative Liabilities (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities		$ (371)	$ (2,423)
Gross amount of assets offset in balance sheet		0	0
Net amount of derivative liabilities presented in balance sheet		(371)	(2,423)
Financial instruments, amount not offset against derivative liabilities in balance sheet		0	0
Derivative, Collateral, Right to Reclaim Securities		17	1,621	[1]
Derivative, Collateral, Right to Reclaim Cash		3
Derivative, Collateral, Right to Reclaim Securities and Cash	[2]	20
Derivative Liability, Fair Value, Amount Offset Against Collateral		(351)	(802)
Foreign currency swaps
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities		(314)	(318)
Gross amount of assets offset in balance sheet		0	0
Net amount of derivative liabilities presented in balance sheet		(314)	(318)
Financial instruments, amount not offset against derivative liabilities in balance sheet		0	0
Derivative, Collateral, Right to Reclaim Securities			0
Derivative, Collateral, Right to Reclaim Securities and Cash		1
Derivative Liability, Fair Value, Amount Offset Against Collateral		(313)	(318)
Foreign currency forwards
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities		(49)	(1,912)
Gross amount of assets offset in balance sheet		0	0
Net amount of derivative liabilities presented in balance sheet		(49)	(1,912)
Financial instruments, amount not offset against derivative liabilities in balance sheet		0	0
Derivative, Collateral, Right to Reclaim Securities			1,439
Derivative, Collateral, Right to Reclaim Securities and Cash		18
Derivative Liability, Fair Value, Amount Offset Against Collateral		(31)	(473)
Foreign currency options
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities		(8)	(33)
Gross amount of assets offset in balance sheet		0	0
Net amount of derivative liabilities presented in balance sheet		(8)	(33)
Financial instruments, amount not offset against derivative liabilities in balance sheet		0	0
Derivative, Collateral, Right to Reclaim Securities			24
Derivative, Collateral, Right to Reclaim Securities and Cash		1
Derivative Liability, Fair Value, Amount Offset Against Collateral		(7)	(9)
Interest rate swaptions
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities			(160)
Gross amount of assets offset in balance sheet			0
Net amount of derivative liabilities presented in balance sheet			(160)
Financial instruments, amount not offset against derivative liabilities in balance sheet			0
Derivative, Collateral, Right to Reclaim Securities			158
Derivative Liability, Fair Value, Amount Offset Against Collateral			(2)
Offsetting liabilities
Offsetting Liabilities [Line Items]
Gross amounts of recognized financial instruments		(1,312)	(4,616)
Gross amounts offset in balance sheet		0	0
Net amounts of financial instruments presented in balance sheet		(1,312)	(4,616)
Carrying value of financial instruments not offset in balance sheet		921	2,149
Collateral not offset in balance sheet		20	1,621
Financial instruments, amount offset against collateral		(371)	(846)
Offsetting liabilities | Securities lending and similar arrangements
Offsetting Liabilities [Line Items]
Gross amounts of recognized financial instruments		(941)	(2,193)
Gross amounts offset in balance sheet		0	0
Net amounts of financial instruments presented in balance sheet		(941)	(2,193)
Carrying value of financial instruments not offset in balance sheet		921	2,149
Collateral not offset in balance sheet		0	0
Financial instruments, amount offset against collateral		$ (20)	$ (44)
[1]	Consists entirely of pledged securities.
[2]	Consists of $17 of pledged securities and $3 of cash

FAIR VALUE MEASUREMENTS - Fair

FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Assets:
Available-for-sale Securities	$ 67,794	$ 68,270
Asset derivatives	676	802
Other Investments	176	171
Cash and cash equivalents	4,350	4,658
Total assets	72,996	73,901
Liabilities:
Liability derivatives	371	2,423
Total Liabilities	371	2,423
Foreign currency swaps
Assets:
Asset derivatives	563	746
Liabilities:
Liability derivatives	314	318
Foreign currency forwards
Assets:
Asset derivatives	107	56
Liabilities:
Liability derivatives	49	1,912
Foreign currency options
Assets:
Asset derivatives	5
Liabilities:
Liability derivatives	8	33
Credit default swaps
Assets:
Asset derivatives	1
Interest rate swaptions
Liabilities:
Liability derivatives		160
Fixed maturities
Assets:
Available-for-sale Securities	65,349	65,573
Fixed maturities | Government and agencies
Assets:
Available-for-sale Securities	19,276	19,198
Fixed maturities | Municipalities
Assets:
Available-for-sale Securities	1,208	1,257
Fixed maturities | Mortgage- and asset-backed securities
Assets:
Available-for-sale Securities	582	602
Fixed maturities | Public utilities
Assets:
Available-for-sale Securities	7,479	7,897
Fixed maturities | Sovereign and supranational
Assets:
Available-for-sale Securities	1,407	1,416
Fixed maturities | Banks/financial institutions
Assets:
Available-for-sale Securities	6,019	6,598
Fixed maturities | Other corporate
Assets:
Available-for-sale Securities	29,378	28,605
Perpetual securities
Assets:
Available-for-sale Securities	1,947	2,669
Perpetual securities | Banks/financial institutions
Assets:
Available-for-sale Securities	1,742	2,438
Perpetual securities | Other corporate
Assets:
Available-for-sale Securities	205	231
Equity securities
Assets:
Available-for-sale Securities	498	28
Level 1
Assets:
Available-for-sale Securities	19,158	18,702
Asset derivatives	0	0
Other Investments	176	171
Cash and cash equivalents	4,350	4,658
Total assets	23,684	23,531
Liabilities:
Total Liabilities	0	0
Level 1 | Foreign currency swaps
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives	0	0
Level 1 | Foreign currency forwards
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives	0	0
Level 1 | Foreign currency options
Assets:
Asset derivatives	0
Liabilities:
Liability derivatives	0	0
Level 1 | Credit default swaps
Assets:
Asset derivatives	0
Level 1 | Interest rate swaptions
Liabilities:
Liability derivatives		0
Level 1 | Fixed maturities
Assets:
Available-for-sale Securities	18,669	18,683
Level 1 | Fixed maturities | Government and agencies
Assets:
Available-for-sale Securities	18,669	18,683
Level 1 | Fixed maturities | Municipalities
Assets:
Available-for-sale Securities	0	0
Level 1 | Fixed maturities | Mortgage- and asset-backed securities
Assets:
Available-for-sale Securities	0	0
Level 1 | Fixed maturities | Public utilities
Assets:
Available-for-sale Securities	0	0
Level 1 | Fixed maturities | Sovereign and supranational
Assets:
Available-for-sale Securities	0	0
Level 1 | Fixed maturities | Banks/financial institutions
Assets:
Available-for-sale Securities	0	0
Level 1 | Fixed maturities | Other corporate
Assets:
Available-for-sale Securities	0	0
Level 1 | Perpetual securities
Assets:
Available-for-sale Securities	0	0
Level 1 | Perpetual securities | Banks/financial institutions
Assets:
Available-for-sale Securities	0	0
Level 1 | Perpetual securities | Other corporate
Assets:
Available-for-sale Securities	0	0
Level 1 | Equity securities
Assets:
Available-for-sale Securities	489	19
Level 2
Assets:
Available-for-sale Securities	48,387	49,167
Asset derivatives	574	696
Other Investments	0	0
Cash and cash equivalents	0	0
Total assets	48,961	49,863
Liabilities:
Total Liabilities	78	2,105
Level 2 | Foreign currency swaps
Assets:
Asset derivatives	462	640
Liabilities:
Liability derivatives	21	0
Level 2 | Foreign currency forwards
Assets:
Asset derivatives	107	56
Liabilities:
Liability derivatives	49	1,912
Level 2 | Foreign currency options
Assets:
Asset derivatives	5
Liabilities:
Liability derivatives	8	33
Level 2 | Credit default swaps
Assets:
Asset derivatives	0
Level 2 | Interest rate swaptions
Liabilities:
Liability derivatives		160
Level 2 | Fixed maturities
Assets:
Available-for-sale Securities	46,434	46,641
Level 2 | Fixed maturities | Government and agencies
Assets:
Available-for-sale Securities	607	515
Level 2 | Fixed maturities | Municipalities
Assets:
Available-for-sale Securities	1,208	1,257
Level 2 | Fixed maturities | Mortgage- and asset-backed securities
Assets:
Available-for-sale Securities	362	379
Level 2 | Fixed maturities | Public utilities
Assets:
Available-for-sale Securities	7,479	7,897
Level 2 | Fixed maturities | Sovereign and supranational
Assets:
Available-for-sale Securities	1,407	1,416
Level 2 | Fixed maturities | Banks/financial institutions
Assets:
Available-for-sale Securities	5,993	6,572
Level 2 | Fixed maturities | Other corporate
Assets:
Available-for-sale Securities	29,378	28,605
Level 2 | Perpetual securities
Assets:
Available-for-sale Securities	1,947	2,520
Level 2 | Perpetual securities | Banks/financial institutions
Assets:
Available-for-sale Securities	1,742	2,289
Level 2 | Perpetual securities | Other corporate
Assets:
Available-for-sale Securities	205	231
Level 2 | Equity securities
Assets:
Available-for-sale Securities	6	6
Level 3
Assets:
Available-for-sale Securities	249	401
Asset derivatives	102	106
Other Investments	0	0
Cash and cash equivalents	0	0
Total assets	351	507
Liabilities:
Total Liabilities	293	318
Level 3 | Foreign currency swaps
Assets:
Asset derivatives	101	106
Liabilities:
Liability derivatives	293	318
Level 3 | Foreign currency forwards
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives	0	0
Level 3 | Foreign currency options
Assets:
Asset derivatives	0
Liabilities:
Liability derivatives	0	0
Level 3 | Credit default swaps
Assets:
Asset derivatives	1
Level 3 | Interest rate swaptions
Liabilities:
Liability derivatives		0
Level 3 | Fixed maturities
Assets:
Available-for-sale Securities	246	249
Level 3 | Fixed maturities | Government and agencies
Assets:
Available-for-sale Securities	0	0
Level 3 | Fixed maturities | Municipalities
Assets:
Available-for-sale Securities	0	0
Level 3 | Fixed maturities | Mortgage- and asset-backed securities
Assets:
Available-for-sale Securities	220	223
Level 3 | Fixed maturities | Public utilities
Assets:
Available-for-sale Securities	0	0
Level 3 | Fixed maturities | Sovereign and supranational
Assets:
Available-for-sale Securities	0	0
Level 3 | Fixed maturities | Banks/financial institutions
Assets:
Available-for-sale Securities	26	26
Level 3 | Fixed maturities | Other corporate
Assets:
Available-for-sale Securities	0	0
Level 3 | Perpetual securities
Assets:
Available-for-sale Securities	0	149
Level 3 | Perpetual securities | Banks/financial institutions
Assets:
Available-for-sale Securities	0	149
Level 3 | Perpetual securities | Other corporate
Assets:
Available-for-sale Securities	0	0
Level 3 | Equity securities
Assets:
Available-for-sale Securities	$ 3	$ 3

FAIR VALUE MEASUREMENTS - Fai78

FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Carried at Cost or Amortized Cost (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Assets:
Securities held to maturity, fixed maturities, amortized cost	$ 33,459	$ 34,242
Securities held to maturity, fixed maturities, fair value	37,520	38,497
Other investments, carried at amortized cost	118
Other investments, carried at amortized cost, fair value	118
Total financial instruments, assets, not carried at fair value	33,577	34,242
Assets, fair value disclosure, financial instruments, carried at cost	37,638	38,497
Liabilities:
Other policyholders' funds	6,285	6,031
Other policyholders' funds fair value disclosure	6,160	5,905
Notes payable	4,991	5,268
Notes payable, fair value disclosure	5,285	5,835
Total financial instrument liabilities not carried at fair value	11,276	11,299
Liabilities fair value disclosure financial instruments carried at cost	11,445	11,740
Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	37,520	38,497
Government and agencies | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, amortized cost	20,004	20,023
Securities held to maturity, fixed maturities, fair value	23,391	23,218
Municipalities | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, amortized cost	341	346
Securities held to maturity, fixed maturities, fair value	415	417
Mortgage- and asset-backed securities | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, amortized cost	36	43
Securities held to maturity, fixed maturities, fair value	38	46
Public utilities | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, amortized cost	3,092	3,342
Securities held to maturity, fixed maturities, fair value	3,203	3,603
Sovereign and supranational | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, amortized cost	2,555	2,556
Securities held to maturity, fixed maturities, fair value	2,711	2,814
Banks/financial institutions | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, amortized cost	4,431	4,932
Securities held to maturity, fixed maturities, fair value	4,546	5,085
Other corporate | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, amortized cost	3,000	3,000
Securities held to maturity, fixed maturities, fair value	3,216	3,314
Level 1
Assets:
Other investments, carried at amortized cost, fair value	0
Assets, fair value disclosure, financial instruments, carried at cost	23,391	23,218
Liabilities:
Other policyholders' funds fair value disclosure	0	0
Notes payable, fair value disclosure	0	0
Liabilities fair value disclosure financial instruments carried at cost	0	0
Level 1 | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	23,391	23,218
Level 1 | Government and agencies | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	23,391	23,218
Level 1 | Municipalities | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	0	0
Level 1 | Mortgage- and asset-backed securities | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	0	0
Level 1 | Public utilities | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	0	0
Level 1 | Sovereign and supranational | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	0	0
Level 1 | Banks/financial institutions | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	0	0
Level 1 | Other corporate | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	0	0
Level 2
Assets:
Other investments, carried at amortized cost, fair value	0
Assets, fair value disclosure, financial instruments, carried at cost	14,103	15,248
Liabilities:
Other policyholders' funds fair value disclosure	0	0
Notes payable, fair value disclosure	0	0
Liabilities fair value disclosure financial instruments carried at cost	0	0
Level 2 | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	14,103	15,248
Level 2 | Government and agencies | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	0	0
Level 2 | Municipalities | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	415	417
Level 2 | Mortgage- and asset-backed securities | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	12	15
Level 2 | Public utilities | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	3,203	3,603
Level 2 | Sovereign and supranational | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	2,711	2,814
Level 2 | Banks/financial institutions | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	4,546	5,085
Level 2 | Other corporate | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	3,216	3,314
Level 3
Assets:
Other investments, carried at amortized cost, fair value	118
Assets, fair value disclosure, financial instruments, carried at cost	144	31
Liabilities:
Other policyholders' funds fair value disclosure	6,160	5,905
Notes payable, fair value disclosure	5,285	5,835
Liabilities fair value disclosure financial instruments carried at cost	11,445	11,740
Level 3 | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	26	31
Level 3 | Government and agencies | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	0	0
Level 3 | Municipalities | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	0	0
Level 3 | Mortgage- and asset-backed securities | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	26	31
Level 3 | Public utilities | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	0	0
Level 3 | Sovereign and supranational | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	0	0
Level 3 | Banks/financial institutions | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	0	0
Level 3 | Other corporate | Fixed maturities
Assets:
Securities held to maturity, fixed maturities, fair value	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Fai79

FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets by Pricing Source, Available-for-sale Securities (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	$ 67,794	$ 68,270
Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	19,158	18,702
Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	48,387	49,167
Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	249	401
Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	65,349	65,573
Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	18,669	18,683
Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	46,434	46,641
Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	246	249
Perpetual securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,947	2,669
Perpetual securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Perpetual securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,947	2,520
Perpetual securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	149
Equity securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	498	28
Equity securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	489	19
Equity securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	6	6
Equity securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	3	3
Equity securities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	495	25
Equity securities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	489	19
Equity securities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	6	6
Equity securities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Equity securities | Net asset value valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	3	3
Equity securities | Net asset value valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Equity securities | Net asset value valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Equity securities | Net asset value valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	3	3
Government and agencies | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	19,276	19,198
Government and agencies | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	18,669	18,683
Government and agencies | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	607	515
Government and agencies | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Government and agencies | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	19,276	19,198
Government and agencies | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	18,669	18,683
Government and agencies | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	607	515
Government and agencies | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Municipalities | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,208	1,257
Municipalities | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Municipalities | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,208	1,257
Municipalities | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Municipalities | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,208	1,257
Municipalities | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Municipalities | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,208	1,257
Municipalities | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Mortgage- and asset-backed securities | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	582	602
Mortgage- and asset-backed securities | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Mortgage- and asset-backed securities | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	362	379
Mortgage- and asset-backed securities | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	220	223
Mortgage- and asset-backed securities | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	362	379
Mortgage- and asset-backed securities | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Mortgage- and asset-backed securities | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	362	379
Mortgage- and asset-backed securities | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Mortgage- and asset-backed securities | Fixed maturities | Consensus pricing valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	220	223
Mortgage- and asset-backed securities | Fixed maturities | Consensus pricing valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Mortgage- and asset-backed securities | Fixed maturities | Consensus pricing valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Mortgage- and asset-backed securities | Fixed maturities | Consensus pricing valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	220	223
Public utilities | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	7,479	7,897
Public utilities | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Public utilities | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	7,479	7,897
Public utilities | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Public utilities | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	7,479	7,897
Public utilities | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Public utilities | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	7,479	7,897
Public utilities | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Sovereign and supranational | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,407	1,416
Sovereign and supranational | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Sovereign and supranational | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,407	1,416
Sovereign and supranational | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Sovereign and supranational | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,407	1,416
Sovereign and supranational | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Sovereign and supranational | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,407	1,416
Sovereign and supranational | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial institutions | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	6,019	6,598
Banks/financial institutions | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial institutions | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	5,993	6,572
Banks/financial institutions | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	26	26
Banks/financial institutions | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	5,993	6,514
Banks/financial institutions | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial institutions | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	5,993	6,514
Banks/financial institutions | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial institutions | Fixed maturities | Consensus pricing valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	26	84
Banks/financial institutions | Fixed maturities | Consensus pricing valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial institutions | Fixed maturities | Consensus pricing valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	58
Banks/financial institutions | Fixed maturities | Consensus pricing valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	26	26
Banks/financial institutions | Perpetual securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,742	2,438
Banks/financial institutions | Perpetual securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial institutions | Perpetual securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,742	2,289
Banks/financial institutions | Perpetual securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	149
Banks/financial institutions | Perpetual securities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,742	2,289
Banks/financial institutions | Perpetual securities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial institutions | Perpetual securities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,742	2,289
Banks/financial institutions | Perpetual securities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial institutions | Perpetual securities | Consensus pricing valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities		149
Banks/financial institutions | Perpetual securities | Consensus pricing valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities		0
Banks/financial institutions | Perpetual securities | Consensus pricing valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities		0
Banks/financial institutions | Perpetual securities | Consensus pricing valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities		149
Other corporate | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	29,378	28,605
Other corporate | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other corporate | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	29,378	28,605
Other corporate | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other corporate | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	29,378	28,605
Other corporate | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other corporate | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	29,378	28,605
Other corporate | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other corporate | Perpetual securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	205	231
Other corporate | Perpetual securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other corporate | Perpetual securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	205	231
Other corporate | Perpetual securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other corporate | Perpetual securities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	205	231
Other corporate | Perpetual securities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other corporate | Perpetual securities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	205	231
Other corporate | Perpetual securities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Fai80

FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels by Pricing Source, Held-to-Maturity Securities (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	$ 37,520	$ 38,497
Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	37,520	38,497
Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	23,391	23,218
Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	14,103	15,248
Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	26	31
Government and agencies | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	23,391	23,218
Government and agencies | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	23,391	23,218
Government and agencies | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Government and agencies | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Government and agencies | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	23,391	23,218
Government and agencies | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	23,391	23,218
Government and agencies | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Government and agencies | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Municipalities | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	415	417
Municipalities | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Municipalities | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	415	417
Municipalities | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Municipalities | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	415	417
Municipalities | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Municipalities | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	415	417
Municipalities | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Mortgage- and asset-backed securities | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	38	46
Mortgage- and asset-backed securities | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Mortgage- and asset-backed securities | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	12	15
Mortgage- and asset-backed securities | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	26	31
Mortgage- and asset-backed securities | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	12	15
Mortgage- and asset-backed securities | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Mortgage- and asset-backed securities | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	12	15
Mortgage- and asset-backed securities | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Mortgage- and asset-backed securities | Fixed maturities | Consensus pricing valuation technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	26	31
Mortgage- and asset-backed securities | Fixed maturities | Consensus pricing valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Mortgage- and asset-backed securities | Fixed maturities | Consensus pricing valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Mortgage- and asset-backed securities | Fixed maturities | Consensus pricing valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	26	31
Public utilities | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	3,203	3,603
Public utilities | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Public utilities | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	3,203	3,603
Public utilities | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Public utilities | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	3,203	3,603
Public utilities | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Public utilities | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	3,203	3,603
Public utilities | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Sovereign and supranational | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	2,711	2,814
Sovereign and supranational | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Sovereign and supranational | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	2,711	2,814
Sovereign and supranational | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Sovereign and supranational | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	2,711	2,814
Sovereign and supranational | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Sovereign and supranational | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	2,711	2,814
Sovereign and supranational | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Banks/financial institutions | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	4,546	5,085
Banks/financial institutions | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Banks/financial institutions | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	4,546	5,085
Banks/financial institutions | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Banks/financial institutions | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	4,546	5,085
Banks/financial institutions | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Banks/financial institutions | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	4,546	5,085
Banks/financial institutions | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Other corporate | Fixed maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	3,216	3,314
Other corporate | Fixed maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Other corporate | Fixed maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	3,216	3,314
Other corporate | Fixed maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Other corporate | Fixed maturities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	3,189	3,287
Other corporate | Fixed maturities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Other corporate | Fixed maturities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	3,189	3,287
Other corporate | Fixed maturities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Other corporate | Fixed maturities | Consensus pricing valuation technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	27	27
Other corporate | Fixed maturities | Consensus pricing valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Other corporate | Fixed maturities | Consensus pricing valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	27	27
Other corporate | Fixed maturities | Consensus pricing valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Chang

FAIR VALUE MEASUREMENTS - Changes in Available-For-Sale Investments and Derivatives Classified as Level 3 (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		$ 189	$ 346
Realized gains or losses included in earnings		(14)	(189)
Unrealized gains or losses included in other comprehensive income (loss)		(4)	(140)
Purchases		0	0
Issuances		0	0
Sales		(147)	(60)
Settlements		34	83
Transfers into Level 3		0	149	[1]
Transfers out of Level 3		0	0
Balance, end of period		58	189
Change in unrealized gain (losses) still held		(14)	(189)
Interest rate swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance, beginning of period	[2]	0	1
Realized gains or losses included in earnings	[2]	0	(1)
Unrealized gains or losses included in other comprehensive income (loss)	[2]	0	0
Purchases	[2]	0	0
Issuances	[2]	0	0
Sales	[2]	0	0
Settlements	[2]	0	0
Transfers into Level 3	[2]	0	0
Transfers out of Level 3	[2]	0	0
Balance, end of period	[2]	0	0
Change in unrealized gain (losses) still held	[2]	0	(1)
Foreign currency swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance, beginning of period	[2]	(212)	(99)
Realized gains or losses included in earnings	[2]	(15)	(191)
Unrealized gains or losses included in other comprehensive income (loss)	[2]	(1)	(17)
Purchases	[2]	0	0
Issuances	[2]	0	0
Sales	[2]	0	0
Settlements	[2]	36	95
Transfers into Level 3	[2]	0	0
Transfers out of Level 3	[2]	0	0
Balance, end of period	[2]	(192)	(212)
Change in unrealized gain (losses) still held	[2]	(15)	(191)
Credit default swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance, beginning of period	[2]	0	(3)
Realized gains or losses included in earnings	[2]	1	3
Unrealized gains or losses included in other comprehensive income (loss)	[2]	0	0
Purchases	[2]	0	0
Issuances	[2]	0	0
Sales	[2]	0	0
Settlements	[2]	0	0
Transfers into Level 3	[2]	0	0
Transfers out of Level 3	[2]	0	0
Balance, end of period	[2]	1	0
Change in unrealized gain (losses) still held	[2]	1	3
Fixed maturities | Mortgage- and asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		223	369
Realized gains or losses included in earnings		0	0
Unrealized gains or losses included in other comprehensive income (loss)		(1)	(134)
Purchases		0	0
Issuances		0	0
Sales		0	0
Settlements		(2)	(12)
Transfers into Level 3		0	0
Transfers out of Level 3		0	0
Balance, end of period		220	223
Change in unrealized gain (losses) still held		0	0
Fixed maturities | Public utilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		0	0
Realized gains or losses included in earnings		0	0
Unrealized gains or losses included in other comprehensive income (loss)		0	0
Purchases		0	0
Issuances		0	0
Sales		0	0
Settlements		0	0
Transfers into Level 3		0	0
Transfers out of Level 3		0	0
Balance, end of period		0	0
Change in unrealized gain (losses) still held		0	0
Fixed maturities | Sovereign and supranational
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		0	0
Realized gains or losses included in earnings		0	0
Unrealized gains or losses included in other comprehensive income (loss)		0	0
Purchases		0	0
Issuances		0	0
Sales		0	0
Settlements		0	0
Transfers into Level 3		0	0
Transfers out of Level 3		0	0
Balance, end of period		0	0
Change in unrealized gain (losses) still held		0	0
Fixed maturities | Banks/financial institutions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		26	23
Realized gains or losses included in earnings		0	0
Unrealized gains or losses included in other comprehensive income (loss)		0	3
Purchases		0	0
Issuances		0	0
Sales		0	0
Settlements		0	0
Transfers into Level 3		0	0
Transfers out of Level 3		0	0
Balance, end of period		26	26
Change in unrealized gain (losses) still held		0	0
Fixed maturities | Other corporate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		0	0
Realized gains or losses included in earnings		0	0
Unrealized gains or losses included in other comprehensive income (loss)		0	0
Purchases		0	0
Issuances		0	0
Sales		0	0
Settlements		0	0
Transfers into Level 3		0	0
Transfers out of Level 3		0	0
Balance, end of period		0	0
Change in unrealized gain (losses) still held		0	0
Perpetual securities | Banks/financial institutions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		149	52
Realized gains or losses included in earnings		0	0
Unrealized gains or losses included in other comprehensive income (loss)		(2)	8
Purchases		0	0
Issuances		0	0
Sales		(147)	(60)
Settlements		0	0
Transfers into Level 3		0	149	[1]
Transfers out of Level 3		0	0
Balance, end of period		0	149
Change in unrealized gain (losses) still held		0	0
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		3	3
Realized gains or losses included in earnings		0	0
Unrealized gains or losses included in other comprehensive income (loss)		0	0
Purchases		0	0
Issuances		0	0
Sales		0	0
Settlements		0	0
Transfers into Level 3		0	0
Transfers out of Level 3		0	0
Balance, end of period		3	3
Change in unrealized gain (losses) still held		$ 0	$ 0
[1]	Due to use of estimated redemption price
[2]	Derivative assets and liabilities are presented net

FAIR VALUE MEASUREMENTS - Addit

FAIR VALUE MEASUREMENTS - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	$ 0	$ 0
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Fai83

FAIR VALUE MEASUREMENTS - Fair Value Inputs Assets Quantitative Information (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 67,794	$ 68,270
Asset derivatives		676	802
Assets, fair value		$ 72,996	$ 73,901
Length of Volatility of Japanese Yen to US Dollar Exchange Rate		10 years	10 years
Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 249	$ 401
Asset derivatives		102	106
Assets, fair value		351	507
Fixed maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		65,349	65,573
Fixed maturities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		246	249
Perpetual securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		1,947	2,669
Perpetual securities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		0	149
Equity securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		498	28
Equity securities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		3	3
Equity securities | Net asset value valuation technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		3	3
Equity securities | Net asset value valuation technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 3	$ 3
Equity securities | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Offered Quotes		$ 1	$ 1
Equity securities | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Offered Quotes		677	677
Equity securities | Assets | Weighted Average | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Offered Quotes		$ 7	$ 6
Mortgage- and asset-backed securities | Fixed maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 582	$ 602
Mortgage- and asset-backed securities | Fixed maturities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		220	223
Mortgage- and asset-backed securities | Fixed maturities | Consensus pricing valuation technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		220	223
Mortgage- and asset-backed securities | Fixed maturities | Consensus pricing valuation technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		220	223
Banks/financial institutions | Fixed maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		6,019	6,598
Banks/financial institutions | Fixed maturities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		26	26
Banks/financial institutions | Fixed maturities | Consensus pricing valuation technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		26	84
Banks/financial institutions | Fixed maturities | Consensus pricing valuation technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		26	26
Banks/financial institutions | Perpetual securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		1,742	2,438
Banks/financial institutions | Perpetual securities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		0	149
Banks/financial institutions | Perpetual securities | Consensus pricing valuation technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			149
Banks/financial institutions | Perpetual securities | Consensus pricing valuation technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			149
Foreign currency swaps
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		563	746
Foreign currency swaps | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		101	106
Credit default swaps
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		1
Credit default swaps | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		1
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Discounted cash flow valuation technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		$ 7	$ 8
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Foreign Exchange Rates	[1]	20.05%	20.50%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk		0.32%	0.16%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk		1.47%	1.05%
Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Discounted cash flow valuation technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		$ 94	$ 98
Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Foreign Exchange Rates	[1]	20.05%	20.50%
Fair value, unobservable input, base correlation, CDS spreads, recovery rate | Credit default swaps | Discounted cash flow valuation technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		$ 1
Fair value, unobservable input, base correlation, CDS spreads, recovery rate | Credit default swaps | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk		1.23%
Fair Value Inputs, Recovery Rate		36.87%
Fair value, unobservable input, base correlation, CDS spreads, recovery rate | Credit default swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Base Correlation	[2]	53.26%
Fair value, unobservable input, base correlation, CDS spreads, recovery rate | Credit default swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Base Correlation	[2]	58.40%
Yen-denominated | Fixed maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 28,511	$ 29,288
Yen-denominated | Equity securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		487	17
Yen-denominated | Mortgage- and asset-backed securities | Fixed maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		355	386
Yen-denominated | Banks/financial institutions | Fixed maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		2,541	2,888
Yen-denominated | Banks/financial institutions | Perpetual securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 1,631	$ 2,263
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	0.42%	0.53%
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	1.22%	1.34%
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	0.42%	0.53%
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	1.22%	1.34%
Dollar-denominated | Fixed maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 36,838	$ 36,285
Dollar-denominated | Equity securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		11	11
Dollar-denominated | Mortgage- and asset-backed securities | Fixed maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		227	216
Dollar-denominated | Banks/financial institutions | Fixed maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		3,478	3,710
Dollar-denominated | Banks/financial institutions | Perpetual securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 111	$ 175
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[4]	2.20%	2.28%
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[4]	2.62%	2.70%
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[4]	2.20%	2.28%
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[4]	2.62%	2.70%
[1]	Based on 10 year volatility of JPY/USD exchange rate
[2]	Range of base correlation for our bespoke tranche for attachment and detachment points corresponding to market indices
[3]	Inputs derived from Japan long-term rates to accommodate long maturity nature of our swaps
[4]	Inputs derived from U.S. long-term rates to accommodate long maturity nature of our swaps

FAIR VALUE MEASUREMENTS - Fai84

FAIR VALUE MEASUREMENTS - Fair Value Inputs Liabilities Quantitative Information (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Liability derivatives		$ 371	$ 2,423
Liabilities, fair value disclosure		$ 371	$ 2,423
Length of Volatility of Japanese Yen to US Dollar Exchange Rate		10 years	10 years
Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Liabilities, fair value disclosure		$ 293	$ 318
Foreign currency swaps
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Liability derivatives		314	318
Foreign currency swaps | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Liability derivatives		293	318
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Discounted cash flow valuation technique | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Liability derivatives		$ 158	$ 176
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Liability | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Foreign Exchange Rates	[1]	20.05%	20.50%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Liability | Lower Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk		0.32%	0.16%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Liability | Upper Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk		1.47%	1.05%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Foreign currency swaps | Discounted cash flow valuation technique | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Liability derivatives		$ 120	$ 111
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Foreign currency swaps | Liability | Lower Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk		0.35%	0.13%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Foreign currency swaps | Liability | Upper Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk		2.13%	1.45%
Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Discounted cash flow valuation technique | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Liability derivatives		$ 15	$ 31
Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Liability | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Foreign Exchange Rates	[1]	20.05%	20.50%
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Liability | Lower Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[2]	0.42%	0.53%
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Liability | Upper Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[2]	1.22%	1.34%
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Foreign currency swaps | Liability | Lower Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[2]	0.42%	0.53%
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Foreign currency swaps | Liability | Upper Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[2]	1.22%	1.34%
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Liability | Lower Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[2]	0.42%	0.53%
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Liability | Upper Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[2]	1.22%	1.34%
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Liability | Lower Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	2.20%	2.28%
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Liability | Upper Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	2.62%	2.70%
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Foreign currency swaps | Liability | Lower Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	2.20%	2.28%
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Foreign currency swaps | Liability | Upper Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	2.62%	2.70%
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Liability | Lower Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	2.20%	2.28%
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Liability | Upper Limit | Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	2.62%	2.70%
[1]	Based on 10 year volatility of JPY/USD exchange rate
[2]	Inputs derived from Japan long-term rates to accommodate long maturity nature of our swaps
[3]	Inputs derived from U.S. long-term rates to accommodate long maturity nature of our swaps

DEFERRED POLICY ACQUISITION C85

DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES - Additional Information (Detail) - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred Policy Acquisition Costs Disclosures [Abstract]
Consolidated policy acquisition costs deferred	$ 1.3	$ 1.3	$ 1.4
Commissions deferred as a percentage of total acquisition costs	74.00%	77.00%	81.00%
Personnel, compensation and benefit expenses as a percentage of insurance expenses	52.00%	52.00%	51.00%

DEFERRED POLICY ACQUISITION C86

DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES - Rollforward of Deferred Policy Acquisition Costs by Segment (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred policy acquisition costs:
Balance, beginning of year	$ 8,273
Capitalization	1,300	$ 1,300	$ 1,400
Amortization	(1,066)	(1,108)	(1,074)
Balance, end of year	8,511	8,273
Aflac U.S.
Deferred policy acquisition costs:
Balance, beginning of year	3,062	2,979
Capitalization	578	548
Amortization	(488)	(459)	(433)
Foreign currency translation and other	(11)	(6)
Balance, end of year	3,141	3,062	2,979
Aflac Japan
Deferred policy acquisition costs:
Balance, beginning of year	5,211	5,819
Capitalization	738	790
Amortization	(578)	(649)	(641)
Foreign currency translation and other	(1)	(749)
Balance, end of year	$ 5,370	$ 5,211	$ 5,819

DEFERRED POLICY ACQUISITION C87

DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES - Advertising Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Advertising Costs [Line Items]
Advertising expense	$ 211	$ 229	$ 240
Aflac Japan
Advertising Costs [Line Items]
Advertising expense	82	103	112
Aflac U.S.
Advertising Costs [Line Items]
Advertising expense	$ 129	$ 126	$ 128

DEFERRED POLICY ACQUISITION C88

DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES - Depreciation and Other Amortization Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred Policy Acquisition Costs Disclosures [Abstract]
Depreciation expense	$ 44	$ 47	$ 56
Other amortization expense	6	8	13
Total depreciation and other amortization expense	$ 50	$ 55	$ 69

DEFERRED POLICY ACQUISITION C89

DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES - Lease and Rental Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Lease and Rental Expense [Line Items]
Lease and rental expense	$ 65	$ 68	$ 66
Aflac Japan
Lease and Rental Expense [Line Items]
Lease and rental expense	46	52	55
Aflac U.S.
Lease and Rental Expense [Line Items]
Lease and rental expense	18	15	10
All other
Lease and Rental Expense [Line Items]
Lease and rental expense	$ 1	$ 1	$ 1

POLICY LIABILITIES - Additional

POLICY LIABILITIES - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Liability for Future Policy Benefit, by Product Segment [Line Items]
Percentage of future policy benefits out of policy liabilities	80.00%
Percentage of unpaid policy claims out of policy liabilities	4.00%
Percentage of unearned premiums out of policy liabilities	9.00%
Percentage of other poliyholders' funds out of policy liabilities	7.00%
Percentage of advanced premiums to unearned premiums	77.00%	80.00%
Percentage of annuities to other policyholders' fund	98.00%	98.00%
Aflac Japan
Liability for Future Policy Benefit, by Product Segment [Line Items]
Weighted-average interest rates reflected in the consolidated statements of earnings for future policy benefits	3.60%	3.80%	3.90%
Aflac U.S.
Liability for Future Policy Benefit, by Product Segment [Line Items]
Weighted-average interest rates reflected in the consolidated statements of earnings for future policy benefits	5.60%	5.70%	5.80%

POLICY LIABILITIES - Liability

POLICY LIABILITIES - Liability for Future Policy Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts	$ 69,687		$ 65,646
Aflac Japan
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	3.60%		3.80%	3.90%
Aflac U.S.
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	5.60%		5.70%	5.80%
Intercompany eliminations | 2015
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	2.00%
Interest Rates In 20 Years	2.00%
Liability amounts	$ (646)	[1]	$ 0
Health insurance | Aflac Japan | 1992 - 2015
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts	$ 7,633		3,900
Health insurance | Aflac Japan | 1992 - 2015 | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	1.25%
Interest Rates In 20 Years	1.25%
Health insurance | Aflac Japan | 1992 - 2015 | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	2.50%
Interest Rates In 20 Years	2.50%
Health insurance | Aflac Japan | 1974 - 2013
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts	$ 1,078		3,449
Health insurance | Aflac Japan | 1974 - 2013 | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	2.70%
Interest Rates In 20 Years	2.25%
Health insurance | Aflac Japan | 1974 - 2013 | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	2.75%
Interest Rates In 20 Years	2.75%
Health insurance | Aflac Japan | 1998 - 2014
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	3.00%
Interest Rates In 20 Years	3.00%
Liability amounts	$ 11,008		10,641
Health insurance | Aflac Japan | 1997 - 1999
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	3.50%
Interest Rates In 20 Years	3.50%
Liability amounts	$ 2,435		2,461
Health insurance | Aflac Japan | 1994 - 1996
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts	$ 2,998		3,023
Health insurance | Aflac Japan | 1994 - 1996 | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	4.00%
Interest Rates In 20 Years	4.00%
Health insurance | Aflac Japan | 1994 - 1996 | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	4.50%
Interest Rates In 20 Years	4.50%
Health insurance | Aflac Japan | 1987 - 1994
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	5.50%
Interest Rates In 20 Years	5.50%
Liability amounts	$ 14,161		14,394
Health insurance | Aflac Japan | 1985 - 1991
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts	$ 1,868		1,923
Health insurance | Aflac Japan | 1985 - 1991 | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	5.25%
Interest Rates In 20 Years	5.25%
Health insurance | Aflac Japan | 1985 - 1991 | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	6.75%
Interest Rates In 20 Years	5.50%
Health insurance | Aflac Japan | 1978 - 1984
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	6.50%
Interest Rates In 20 Years	5.50%
Liability amounts	$ 2,163		2,260
Health insurance | Aflac U.S. | 2013 - 2015
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts	$ 57		42
Health insurance | Aflac U.S. | 2013 - 2015 | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	3.00%
Interest Rates In 20 Years	3.00%
Health insurance | Aflac U.S. | 2013 - 2015 | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	3.50%
Interest Rates In 20 Years	3.50%
Health insurance | Aflac U.S. | 2012 - 2015
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	3.75%
Interest Rates In 20 Years	3.75%
Liability amounts	$ 794		546
Health insurance | Aflac U.S. | 2011
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	4.75%
Interest Rates In 20 Years	4.75%
Liability amounts	$ 300		276
Health insurance | Aflac U.S. | 2005 - 2010
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	5.50%
Interest Rates In 20 Years	5.50%
Liability amounts	$ 2,986		2,951
Health insurance | Aflac U.S. | 1988 - 2004
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	8.00%
Interest Rates In 20 Years	6.00%
Liability amounts	$ 687		706
Health insurance | Aflac U.S. | 1986 - 2004
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	6.00%
Interest Rates In 20 Years	6.00%
Liability amounts	$ 1,276		1,293
Health insurance | Aflac U.S. | 1981 - 1986
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts	$ 174		183
Health insurance | Aflac U.S. | 1981 - 1986 | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	6.50%
Interest Rates In 20 Years	5.50%
Health insurance | Aflac U.S. | 1981 - 1986 | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	7.00%
Interest Rates In 20 Years	6.50%
Health insurance | Aflac U.S. | 1998 - 2004
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	7.00%
Interest Rates In 20 Years	7.00%
Liability amounts	$ 1,279		1,260
Health insurance | Aflac U.S. | Other years
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts	21		21
Life insurance | Aflac Japan | 2001 - 2015
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts	$ 5,441		3,986
Life insurance | Aflac Japan | 2001 - 2015 | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	1.50%
Interest Rates In 20 Years	1.50%
Life insurance | Aflac Japan | 2001 - 2015 | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	1.85%
Interest Rates In 20 Years	1.85%
Life insurance | Aflac Japan | 2011 - 2015
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	2.00%
Interest Rates In 20 Years	2.00%
Liability amounts	$ 3,226		2,298
Life insurance | Aflac Japan | 2009 - 2011
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	2.25%
Interest Rates In 20 Years	2.25%
Liability amounts	$ 2,332		1,890
Life insurance | Aflac Japan | 1992 - 2006
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	2.35%
Interest Rates In 20 Years	1.77%
Liability amounts	$ 5		0
Life insurance | Aflac Japan | 2005 - 2011
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	2.50%
Interest Rates In 20 Years	2.50%
Liability amounts	$ 1,330		1,214
Life insurance | Aflac Japan | 1985 - 2006
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	2.70%
Interest Rates In 20 Years	2.25%
Liability amounts	$ 1,962		2,006
Life insurance | Aflac Japan | 2007 - 2011
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	2.75%
Interest Rates In 20 Years	2.75%
Liability amounts	$ 1,105		1,010
Life insurance | Aflac Japan | 1999 - 2011
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	3.00%
Interest Rates In 20 Years	3.00%
Liability amounts	$ 1,988		1,944
Life insurance | Aflac Japan | 1996 - 2009
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	3.50%
Interest Rates In 20 Years	3.50%
Liability amounts	$ 635		633
Life insurance | Aflac Japan | 1994 -1996
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts	$ 877		884
Life insurance | Aflac Japan | 1994 -1996 | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	4.00%
Interest Rates In 20 Years	4.00%
Life insurance | Aflac Japan | 1994 -1996 | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	4.50%
Interest Rates In 20 Years	4.50%
Life insurance | Aflac U.S. | 1956 - 2015
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts	$ 514		$ 452
Life insurance | Aflac U.S. | 1956 - 2015 | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	3.50%
Interest Rates In 20 Years	3.50%
Life insurance | Aflac U.S. | 1956 - 2015 | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Interest Rates Year of Issue	6.00%
Interest Rates In 20 Years	6.00%
[1]	Elimination entry necessary due to recapture of a portion of policy liabilities ceded externally, as a result of the reinsurance retrocession transaction as described in Note 8 of the Notes to the Consolidated Financial Statements

POLICY LIABILITIES - Changes in

POLICY LIABILITIES - Changes in Liability for Unpaid Policy Claims (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Liability for Unpaid Claims and Claims Expenses
Unpaid supplemental health claims, beginning of year	$ 3,630	$ 3,763
Net balance, beginning of year	3,630
Less claims paid during the year on claims incurred during:
Net balance, end of year	3,802	3,630
Total liability for unpaid policy claims	3,802	3,630	$ 3,763
Health insurance
Liability for Unpaid Claims and Claims Expenses
Unpaid supplemental health claims, beginning of year	3,412	3,537	3,781
Less reinsurance recoverables	7	9	10
Net balance, beginning of year	3,405	3,528	3,771
Add claims incurred during the year related to:
Current year	6,416	6,866	7,215
Prior years	(353)	(301)	(236)
Total incurred	6,063	6,565	6,979
Less claims paid during the year on claims incurred during:
Current year	4,227	4,532	4,834
Prior years	1,718	1,873	1,931
Total paid	5,945	6,405	6,765
Effect of foreign exchange rate changes on unpaid claims	(1)	(283)	(457)
Net balance, end of year	3,522	3,405	3,528
Add reinsurance recoverables	26	7	9
Total liability for unpaid policy claims	3,548	3,412	3,537
Life insurance
Liability for Unpaid Claims and Claims Expenses
Unpaid supplemental health claims, beginning of year	218	226
Less claims paid during the year on claims incurred during:
Total liability for unpaid policy claims	$ 254	$ 218	$ 226

REINSURANCE Additional Informat

REINSURANCE Additional Information (Detail) - 12 months ended Dec. 31, 2015 $ in Millions, ¥ in Billions	USD ($)	JPY (¥)
Aflac Japan
Effects of Reinsurance [Line Items]
Committed reinsurance facility | ¥		¥ 110
Aflac Japan | Closed Block- Tranche Three
Effects of Reinsurance [Line Items]
Coinsurance reinsurance ceded percentage	30.00%
Reinsurance assumed percentage	27.00%
Aflac Japan | Closed Medical Block - Tranche Two
Effects of Reinsurance [Line Items]
Coinsurance reinsurance ceded percentage	16.70%
Aflac Japan | Closed Medical Block - Tranche One
Effects of Reinsurance [Line Items]
Coinsurance reinsurance ceded percentage	33.30%
Aflac Japan | Closed block
Effects of Reinsurance [Line Items]
Reinsurance assumed percentage	8.35%
Reinsurance deferred profit liability	$ 786
Reinsurance recoverables	805
Letter of credit
Effects of Reinsurance [Line Items]
Collateral posted for reinsurance	$ 80

REINSURANCE Effect of Reinsuran

REINSURANCE Effect of Reinsurance on Premiums and Benefits and Claims (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effects of Reinsurance [Line Items]
Direct premiums earned									$ 17,904	$ 19,412	$ 20,233
Ceded premiums									(520)	(350)	(110)
Assumed premiums earned									186	10	12
Net premium income	$ 4,394	$ 4,380	$ 4,364	$ 4,432	$ 4,489	$ 4,841	$ 4,888	$ 4,854	17,570	19,072	20,135
Direct benefits and claims									12,041	13,235
Benefits and claims, net									11,746	12,937	13,813
All other
Effects of Reinsurance [Line Items]
Ceded premiums									(39)	(39)
Assumed premiums earned									8	10
Ceded benefits and claims									16	(27)
Assumed benefits and claims from other companies									(41)	5
Aflac Japan
Effects of Reinsurance [Line Items]
Net premium income									12,046	13,861	14,982
Benefits and claims, net									8,705	10,084	$ 10,924
Aflac Japan | Closed block
Effects of Reinsurance [Line Items]
Ceded premiums									(481)	(311)
Assumed premiums earned									178	0
Ceded benefits and claims									(437)	(276)
Assumed benefits and claims from other companies									$ 167	$ 0

NOTES PAYABLE - Additional Info

NOTES PAYABLE - Additional Information (Detail)	1 Months Ended																	12 Months Ended
	Aug. 31, 2015USD ($)	Aug. 31, 2015JPY (¥)	Jul. 31, 2015USD ($)	Jul. 31, 2015JPY (¥)	Apr. 30, 2015USD ($)	Mar. 31, 2015USD ($)series	Nov. 30, 2014USD ($)	Jun. 30, 2013USD ($)	Oct. 31, 2012USD ($)	Sep. 30, 2012USD ($)	Jul. 31, 2012USD ($)	Feb. 29, 2012USD ($)series	Jul. 31, 2011JPY (¥)series	Aug. 31, 2010USD ($)	Dec. 31, 2009USD ($)	May. 31, 2009USD ($)	Sep. 30, 2006JPY (¥)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2009JPY (¥)	Dec. 31, 2015JPY (¥)	Mar. 31, 2015JPY (¥)series	Dec. 31, 2014JPY (¥)	Nov. 30, 2014JPY (¥)	Jun. 30, 2013JPY (¥)	Oct. 31, 2012JPY (¥)	Sep. 30, 2012JPY (¥)	Feb. 29, 2012JPY (¥)series
Debt Instrument [Line Items]
Number of series of senior notes issued through a U.S. public debt offering (in series) | series						2						2	3										2						2
Principal payments under debt obligations																		$ 1,272,000,000	$ 335,000,000	$ 0
3.45% senior notes paid August 2015
Debt Instrument [Line Items]
Repayments of Debt	$ 300,000,000
Debt instrument, interest rate																			3.45%					3.45%
Debt Instrument, term														5 years
Debt instrument, principal amount														$ 300,000,000
2.65% senior notes due February 2017
Debt Instrument [Line Items]
Debt instrument, interest rate											2.65%	2.65%						2.65%	2.65%			2.65%		2.65%					2.65%
Debt Instrument, term											5 years	5 years
Debt instrument effective principal amount after cross currency swap | ¥																													¥ 30,900,000,000
Debt instrument, principal amount											$ 250,000,000	$ 400,000,000						$ 400,000,000
Debt instrument, effective interest rate												1.22%																	1.22%
8.50% senior notes due May 2019
Debt Instrument [Line Items]
Debt instrument, interest rate					8.50%														8.50%					8.50%
Debt Instrument, term																10 years
Debt instrument, principal amount																$ 850,000,000
Principal payments under debt obligations					$ 850,000,000
Expense on extinguishment of debt, make-whole premium					$ 230,000,000													$ 230,000,000
2.40% senior notes due March 2020
Debt Instrument [Line Items]
Debt instrument, interest rate						2.40%												2.40%				2.40%	2.40%
Debt Instrument, term						5 years
Debt instrument effective principal amount after cross currency swap | ¥																							¥ 67,000,000,000
Debt instrument, principal amount						$ 550,000,000												$ 550,000,000
Debt instrument, effective interest rate						0.24%																	0.24%
4.00% senior notes due February 2022
Debt Instrument [Line Items]
Debt instrument, interest rate												4.00%						4.00%	4.00%			4.00%		4.00%					4.00%
Debt Instrument, term												10 years
Debt instrument effective principal amount after cross currency swap | ¥																													¥ 27,000,000,000
Debt instrument, principal amount												$ 350,000,000						$ 350,000,000
Debt instrument, effective interest rate												2.07%																	2.07%
3.625% senior notes due June 2023
Debt Instrument [Line Items]
Debt instrument, interest rate								3.625%										3.625%	3.625%			3.625%		3.625%		3.625%
Debt Instrument, term								10 years
Debt Instrument, redemption, description								These notes are redeemable at our option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the treasury rate plus 20 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date.
Debt instrument effective principal amount after cross currency swap | ¥																										¥ 69,800,000,000
Debt instrument, principal amount								$ 700,000,000										$ 700,000,000
Debt instrument, effective interest rate								1.50%																		1.50%
3.625% senior notes due November 2024
Debt Instrument [Line Items]
Debt instrument, interest rate							3.625%											3.625%	3.625%			3.625%		3.625%	3.625%
Debt Instrument, term							10 years
Debt Instrument, redemption, description							These notes are redeemable at our option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the treasury rate plus 20 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date.
Debt instrument effective principal amount after cross currency swap | ¥																									¥ 85,300,000,000
Debt instrument, principal amount							$ 750,000,000											$ 750,000,000
Debt instrument, effective interest rate							1.00%																		1.00%
3.25% senior notes due March 2025
Debt Instrument [Line Items]
Debt instrument, interest rate						3.25%												3.25%				3.25%	3.25%
Debt Instrument, term						10 years
Debt instrument effective principal amount after cross currency swap | ¥																							¥ 55,000,000,000
Debt instrument, principal amount						$ 450,000,000												$ 450,000,000
Debt instrument, effective interest rate						0.82%																	0.82%
6.90% senior notes due December 2039
Debt Instrument [Line Items]
Debt instrument, interest rate																		6.90%	6.90%			6.90%		6.90%
Debt Instrument, term															30 years
Debt instrument, principal amount															$ 400,000,000
6.45% senior notes due August 2040
Debt Instrument [Line Items]
Debt instrument, interest rate																		6.45%	6.45%			6.45%		6.45%
Debt Instrument, term														30 years
Debt instrument, principal amount														$ 450,000,000
5.50% subordinated notes due September 2052
Debt Instrument [Line Items]
Debt instrument, interest rate									5.50%	5.50%								5.50%	5.50%			5.50%		5.50%			5.50%	5.50%
Debt Instrument, term										40 years
Debt instrument effective principal amount after cross currency swap | ¥																											¥ 3,900,000,000	¥ 35,300,000,000
Debt instrument, principal amount									$ 50,000,000	$ 450,000,000								$ 500,000,000
Minimum prinicipal amount outstanding following partial redemption																		$ 25,000,000
Debt instrument, effective interest rate									4.42%	4.41%																	4.42%	4.41%
Derivative, Term of Contract									5 years	5 years
2.26% yen-denominated Uridashi notes due September 2016
Debt Instrument [Line Items]
Debt instrument, interest rate																		2.26%	2.26%			2.26%		2.26%
Debt Instrument, term																	10 years
Principal payments under debt obligations | ¥																					¥ 1,400,000,000
Debt instrument, principal amount | ¥																	¥ 10,000,000,000					¥ 8,000,000,000		¥ 8,000,000,000
Extinguishment of notes | ¥																					2,000,000,000
Expense on extinguishment of debt, make-whole premium | ¥																					¥ (600,000,000)
1.84% yen-denominated Samurai notes due July 2016
Debt Instrument [Line Items]
Debt instrument, interest rate													1.84%					1.84%	1.84%			1.84%		1.84%
Debt Instrument, term													5 years
Debt instrument, principal amount | ¥													¥ 15,800,000,000									¥ 15,800,000,000		¥ 15,800,000,000
3.60% yen-denominated loan paid July 2015
Debt Instrument [Line Items]
Repayments of Debt			$ 81,000,000	¥ 10,000,000,000
Debt instrument, interest rate																			3.60%					3.60%
Debt instrument, principal amount | ¥																								¥ 10,000,000,000
3.00% yen-denominated loan paid August 2015
Debt Instrument [Line Items]
Repayments of Debt	$ 41,000,000	¥ 5,000,000,000
Debt instrument, interest rate																			3.00%					3.00%
Debt instrument, principal amount | ¥																								¥ 5,000,000,000
1.47% yen-denominated Samurai notes paid July 2014
Debt Instrument [Line Items]
Debt instrument, principal amount | ¥													28,700,000,000
Variable interest rate yen-denominated Samurai notes paid July 2014
Debt Instrument [Line Items]
Debt instrument, principal amount | ¥													5,500,000,000
Senior Notes
Debt Instrument [Line Items]
Debt instrument, principal amount						$ 1,000,000,000						$ 750,000,000
Yen-denominated Samurai notes
Debt Instrument [Line Items]
Debt instrument, principal amount | ¥													¥ 50,000,000,000
Notes Payable
Debt Instrument [Line Items]
Debt instrument, debt default, amount																		$ 0	$ 0
Lines of credit
Debt Instrument [Line Items]
Debt instrument, debt default, amount																		$ 0	$ 0
50 billion yen line of credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity | ¥																						50,000,000,000
55 billion yen line of credit
Debt Instrument [Line Items]
Line of credit facility term																		5 years
Line of credit facility, maximum borrowing capacity | ¥																						55,000,000,000
Line of credit facility, interest rate description																		Borrowings bear interest at a rate per annum equal to, at our option, either (a) a eurocurrency rate determined by reference to the London Interbank Offered Rate (LIBOR) for the interest period relevant to such borrowing adjusted for certain additional costs or (b) a base rate determined by reference to the highest of (1) the federal funds effective rate plus ½ of 1%, (2) the rate of interest for such day announced by Mizuho Bank, Ltd. as its prime rate and (3) the eurocurrency rate for an interest period of one month plus 1.00%, in each case plus an applicable margin. The applicable margin ranges between .79% and 1.275% for eurocurrency rate borrowings and 0.0% and .275% for base rate borrowings, depending on the Parent Company’s debt ratings as of the date of determination.
Line of credit facility, amount outstanding | ¥																						¥ 0
$100 million dollar line of credit
Debt Instrument [Line Items]
Line of credit facility term																		364 days
Line of credit facility, maximum borrowing capacity																		$ 100,000,000
Line of credit facility, interest rate description																		Borrowings will bear interest at the rate quoted by the bank and agreed upon at the time of making such loan and will have a three-month maturity period.
Line of credit facility, amount outstanding																		$ 0
$50 million dollar line of credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity																		$ 50,000,000
Line of credit facility, interest rate description																		Borrowings will bear interest at the rate quoted by the bank and agreed upon at the time of making such loan and will have a three-month maturity period.
Line of credit facility, amount outstanding																		$ 0
Upper Limit | 55 billion yen line of credit
Debt Instrument [Line Items]
Line of credit facility, commitment fee percentage																		0.225%
Lower Limit | 55 billion yen line of credit
Debt Instrument [Line Items]
Line of credit facility, commitment fee percentage																		0.085%

NOTES PAYABLE - Summary of Note

NOTES PAYABLE - Summary of Notes Payable (Detail) $ in Millions, ¥ in Billions		Dec. 31, 2015USD ($)		Dec. 31, 2015JPY (¥)	Apr. 30, 2015	Mar. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2014JPY (¥)	Nov. 30, 2014USD ($)	Jun. 30, 2013USD ($)	Oct. 31, 2012USD ($)	Sep. 30, 2012USD ($)	Jul. 31, 2012USD ($)	Feb. 29, 2012USD ($)	Jul. 31, 2011JPY (¥)	Aug. 31, 2010USD ($)	Dec. 31, 2009USD ($)	May. 31, 2009USD ($)	Sep. 30, 2006JPY (¥)
Debt Instrument [Line Items]
Notes payable		$ 5,011					$ 5,282
3.45% senior notes paid August 2015
Debt Instrument [Line Items]
Notes payable		0					$ 300
Debt instrument, principal amount																$ 300
Debt instrument, interest rate							3.45%	3.45%
2.65% senior notes due February 2017
Debt Instrument [Line Items]
Notes payable	[1]	652					$ 653
Debt instrument, principal amount		$ 400											$ 250	$ 400
Debt instrument, interest rate		2.65%		2.65%			2.65%	2.65%					2.65%	2.65%
8.50% senior notes due May 2019
Debt Instrument [Line Items]
Notes payable		$ 0	[2]				$ 850
Debt instrument, principal amount																		$ 850
Debt instrument, interest rate					8.50%		8.50%	8.50%
2.40% senior notes due March 2020
Debt Instrument [Line Items]
Notes payable		550					$ 0
Debt instrument, principal amount		$ 550				$ 550
Debt instrument, interest rate		2.40%		2.40%		2.40%
4.00% senior notes due February 2022
Debt Instrument [Line Items]
Notes payable		$ 350					$ 350
Debt instrument, principal amount		$ 350												$ 350
Debt instrument, interest rate		4.00%		4.00%			4.00%	4.00%						4.00%
3.625% senior notes due June 2023
Debt Instrument [Line Items]
Notes payable		$ 700					$ 700
Debt instrument, principal amount		$ 700								$ 700
Debt instrument, interest rate		3.625%		3.625%			3.625%	3.625%		3.625%
3.625% senior notes due November 2024
Debt Instrument [Line Items]
Notes payable	[3]	$ 749					$ 749
Debt instrument, principal amount		$ 750							$ 750
Debt instrument, interest rate		3.625%		3.625%			3.625%	3.625%	3.625%
3.25% senior notes due March 2025
Debt Instrument [Line Items]
Notes payable		$ 448	[3]				$ 0
Debt instrument, principal amount		$ 450				$ 450
Debt instrument, interest rate		3.25%		3.25%		3.25%
6.90% senior notes due December 2039
Debt Instrument [Line Items]
Notes payable	[3]	$ 397					$ 397
Debt instrument, principal amount																	$ 400
Debt instrument, interest rate		6.90%		6.90%			6.90%	6.90%
6.45% senior notes due August 2040
Debt Instrument [Line Items]
Notes payable	[3]	$ 448					$ 448
Debt instrument, principal amount																$ 450
Debt instrument, interest rate		6.45%		6.45%			6.45%	6.45%
5.50% subordinated notes due September 2052
Debt Instrument [Line Items]
Notes payable		$ 500					$ 500
Debt instrument, principal amount		$ 500									$ 50	$ 450
Debt instrument, interest rate		5.50%		5.50%			5.50%	5.50%			5.50%	5.50%
2.26% yen-denominated Uridashi notes due September 2016
Debt Instrument [Line Items]
Notes payable		$ 66					$ 66
Debt instrument, principal amount | ¥				¥ 8				¥ 8											¥ 10
Debt instrument, interest rate		2.26%		2.26%			2.26%	2.26%
1.84% yen-denominated Samurai notes due July 2016
Debt Instrument [Line Items]
Notes payable		$ 131					$ 131
Debt instrument, principal amount | ¥				¥ 15.8				¥ 15.8							¥ 15.8
Debt instrument, interest rate		1.84%		1.84%			1.84%	1.84%							1.84%
3.60% yen-denominated loan paid July 2015
Debt Instrument [Line Items]
Notes payable		$ 0					$ 83
Debt instrument, principal amount | ¥								¥ 10
Debt instrument, interest rate							3.60%	3.60%
3.00% yen-denominated loan paid August 2015
Debt Instrument [Line Items]
Notes payable		0					$ 41
Debt instrument, principal amount | ¥								¥ 5
Debt instrument, interest rate							3.00%	3.00%
Capitalized lease obligations
Debt Instrument [Line Items]
Notes payable		$ 20					$ 14
[1]	Principal amount plus an issuance premium that is being amortized over the life of the notes
[2]	Redeemed in April 2015
[3]	Principal amount net of an issuance discount that is being amortized over the life of the notes

NOTES PAYABLE - Aggregate Contr

NOTES PAYABLE - Aggregate Contractual Maturities of Notes Payable (Detail) $ in Millions	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
2,016	$ 203
2,017	655
2,018	4
2,019	3
2,020	551
Thereafter	3,601
Total	5,017
Long-term debt
Debt Instrument [Line Items]
2,016	197
2,017	650
2,018	0
2,019	0
2,020	550
Thereafter	3,600
Total	4,997
Capitalized lease obligations
Debt Instrument [Line Items]
2,016	6
2,017	5
2,018	4
2,019	3
2,020	1
Thereafter	1
Total	$ 20

NOTES PAYABLE Summary of Notes

NOTES PAYABLE Summary of Notes Payable Parenthetical (Details) $ in Millions, ¥ in Billions	Dec. 31, 2015USD ($)	Dec. 31, 2015JPY (¥)	Apr. 30, 2015	Mar. 31, 2015USD ($)	Dec. 31, 2014JPY (¥)	Nov. 30, 2014USD ($)	Jun. 30, 2013USD ($)	Oct. 31, 2012USD ($)	Sep. 30, 2012USD ($)	Jul. 31, 2012USD ($)	Feb. 29, 2012USD ($)	Jul. 31, 2011JPY (¥)	Aug. 31, 2010USD ($)	Dec. 31, 2009USD ($)	May. 31, 2009USD ($)	Sep. 30, 2006JPY (¥)
3.45% senior notes paid August 2015
Debt Instrument [Line Items]
Debt instrument, interest rate					3.45%
Debt instrument, principal amount													$ 300
2.65% senior notes due February 2017
Debt Instrument [Line Items]
Debt instrument, interest rate	2.65%	2.65%			2.65%					2.65%	2.65%
Debt instrument, principal amount	$ 400									$ 250	$ 400
8.50% senior notes due May 2019
Debt Instrument [Line Items]
Debt instrument, interest rate			8.50%		8.50%
Debt instrument, principal amount															$ 850
2.40% senior notes due March 2020
Debt Instrument [Line Items]
Debt instrument, interest rate	2.40%	2.40%		2.40%
Debt instrument, principal amount	$ 550			$ 550
4.00% senior notes due February 2022
Debt Instrument [Line Items]
Debt instrument, interest rate	4.00%	4.00%			4.00%						4.00%
Debt instrument, principal amount	$ 350										$ 350
3.625% senior notes due June 2023
Debt Instrument [Line Items]
Debt instrument, interest rate	3.625%	3.625%			3.625%		3.625%
Debt instrument, principal amount	$ 700						$ 700
3.625% senior notes due November 2024
Debt Instrument [Line Items]
Debt instrument, interest rate	3.625%	3.625%			3.625%	3.625%
Debt instrument, principal amount	$ 750					$ 750
3.25% senior notes due March 2025
Debt Instrument [Line Items]
Debt instrument, interest rate	3.25%	3.25%		3.25%
Debt instrument, principal amount	$ 450			$ 450
6.90% senior notes due December 2039
Debt Instrument [Line Items]
Debt instrument, interest rate	6.90%	6.90%			6.90%
Debt instrument, principal amount														$ 400
6.45% senior notes due August 2040
Debt Instrument [Line Items]
Debt instrument, interest rate	6.45%	6.45%			6.45%
Debt instrument, principal amount													$ 450
5.50% subordinated notes due September 2052
Debt Instrument [Line Items]
Debt instrument, interest rate	5.50%	5.50%			5.50%			5.50%	5.50%
Debt instrument, principal amount	$ 500							$ 50	$ 450
2.26% yen-denominated Uridashi notes due September 2016
Debt Instrument [Line Items]
Debt instrument, interest rate	2.26%	2.26%			2.26%
Debt instrument, principal amount | ¥		¥ 8			¥ 8											¥ 10
1.84% yen-denominated Samurai notes due July 2016
Debt Instrument [Line Items]
Debt instrument, interest rate	1.84%	1.84%			1.84%							1.84%
Debt instrument, principal amount | ¥		¥ 15.8			¥ 15.8							¥ 15.8
3.60% yen-denominated loan paid July 2015
Debt Instrument [Line Items]
Debt instrument, interest rate					3.60%
Debt instrument, principal amount | ¥					¥ 10
3.00% yen-denominated loan paid August 2015
Debt Instrument [Line Items]
Debt instrument, interest rate					3.00%
Debt instrument, principal amount | ¥					¥ 5

INCOME TAXES - Additional Infor

INCOME TAXES - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jan. 01, 2015	Apr. 01, 2012
Income Taxes [Line Items]
Unrecognized tax benefit, deductibility highly certain, timing uncertain	$ 261	$ 307
Japan Tax Rate				30.80%	33.30%
Deferred tax expense (benefit)	$ 41	$ 461	$ 422
The expected U.S. tax rate	35.00%	35.00%	35.00%
Income tax expense (benefit) related to items of other comprehensive income (loss)	$ (901)	$ 1,803	$ (581)
Non-life operating loss carryforwards, limitations	only 35% of non-life operating losses can be offset against life insurance taxable income each year
Tax credit carryforward, amount	$ 0
Unrecognized tax benefits, permanent uncertainties	3
Unrecognized tax benefits, interest and penalties expense	11	11	11
Unrecognized tax benefits, accrued interest and penalties	22	30
Capital loss carryforwards	0
Expiring in 2035
Income Taxes [Line Items]
Non-life operating loss carryforwards	1
Aflac Japan
Income Taxes [Line Items]
Deferred tax expense (benefit)	42	125	299
Aflac Japan | Dollar denominated investment portfolio
Income Taxes [Line Items]
Income tax expense (benefit) related to items of other comprehensive income (loss)			$ 614
Effective income tax rate excluding income tax expense (benefit) related to Aflac Japan's dollar-denominated portfolio			31.00%
Aflac U.S.
Income Taxes [Line Items]
Deferred tax expense (benefit)	$ (1)	$ 336	$ 123

INCOME TAXES - Components of In

INCOME TAXES - Components of Income Tax Expense (Benefit) Applicable to Pretax Earnings (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of Provision of Income Taxes [Line Items]
Current									$ 1,288	$ 1,079	$ 1,236
Deferred									41	461	422
Total income tax expense	$ 380	$ 297	$ 301	$ 350	$ 372	$ 368	$ 428	$ 372	1,329	1,540	1,658
Aflac U.S.
Reconciliation of Provision of Income Taxes [Line Items]
Current									225	84	302
Deferred									(1)	336	123
Total income tax expense									224	420	425
Aflac Japan
Reconciliation of Provision of Income Taxes [Line Items]
Current									1,063	995	934
Deferred									42	125	299
Total income tax expense									$ 1,105	$ 1,120	$ 1,233

INCOME TAXES - Principal Reason

INCOME TAXES - Principal Reasons for Differences and Related Tax Effects where Income Tax Expense Varies from Amount Computed by Applying Expected United States Tax Rate of Thirty Five Percent to Pretax Earnings (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Income taxes based on U.S. statutory rates									$ 1,352	$ 1,572	$ 1,685
Utilization of foreign tax credit									(27)	(32)	(37)
Nondeductible expenses									3	5	6
Other, net									1	(5)	4
Total income tax expense	$ 380	$ 297	$ 301	$ 350	$ 372	$ 368	$ 428	$ 372	$ 1,329	$ 1,540	$ 1,658

INCOME TAXES - Total Income Tax

INCOME TAXES - Total Income Tax Expense (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Statements of earnings	$ 380	$ 297	$ 301	$ 350	$ 372	$ 368	$ 428	$ 372	$ 1,329	$ 1,540	$ 1,658
Other comprehensive income (loss):
Unrealized foreign currency translation gains (losses) during period									16	(419)	253
Unrealized gains (losses) on investment securities:
Unrealized holding gains (losses) on investment securities during period									(931)	2,237	(904)
Reclassification adjustment for realized (gains) losses on investment securities included in net earnings									21	19	19
Unrealized gains (losses) on derivatives during period									0	(3)	(4)
Pension liability adjustment during period									(7)	(31)	55
Total income tax expense (benefit) related to items of other comprehensive income (loss)									(901)	1,803	(581)
Additional paid-in capital (exercise of stock options)									4	(7)	(8)
Total income taxes									$ 432	$ 3,336	$ 1,069

INCOME TAXES - Income Tax Effec

INCOME TAXES - Income Tax Effects of Temporary Differences that Gave Rise to Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Deferred income tax liabilities:
Deferred policy acquisition costs	$ 2,282	$ 2,209
Unrealized gains on investment securities	1,684	2,584
Premiums receivable	139	139
Policy benefit reserves	1,313	1,376
Depreciation	61	51
Other	0	20
Total deferred income tax liabilities	5,479	6,379
Deferred income tax assets:
Other basis differences in investment securities	1,422	1,331
Unfunded retirement benefits	15	16
Other accrued expenses	7	4
Policy and contract claims	113	99
Foreign currency loss on Japan branch	208	327
Deferred compensation	181	226
Capital loss carryforwards	0	26
Other	95	0
Total deferred income tax assets	2,041	2,029
Net deferred income tax liability	3,438	4,350
Current income tax liability	902	943
Total income tax liability	$ 4,340	$ 5,293

INCOME TAXES - Reconciliation o

INCOME TAXES - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance, beginning of year	$ 309	$ 328
Additions for tax positions of prior years	0	2
Reductions for tax positions of prior years	(45)	(21)
Balance, end of year	$ 264	$ 309

SHAREHOLDERS' EQUITY - Addition

SHAREHOLDERS' EQUITY - Additional Information (Detail) shares in Millions	12 Months Ended
	Dec. 31, 2015Voteshares	Dec. 31, 2014shares	Dec. 31, 2013shares	Aug. 31, 2015shares
Stockholders Equity Note [Line Items]
Common stock, voting rights	are generally entitled to one vote per share until they have been held by the same beneficial owner for a continuous period of 48 months, at which time they become entitled to 10 votes per share.
Voting rights, votes per share | Vote	1
Remaining common stock available for purchase under share repurchase authorizations	48.4
The expected U.S. tax rate	35.00%	35.00%	35.00%
Share repurchase program
Stockholders Equity Note [Line Items]
Stock acquired in open market, shares	21.2	19.7	13.2
Share Repurchase Authorization 2015 [Member]
Stockholders Equity Note [Line Items]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased				40
Share Held For Continuous Forty Eight Month Period
Stockholders Equity Note [Line Items]
Voting rights, votes per share | Vote	10

SHAREHOLDERS' EQUITY - Reconcil

SHAREHOLDERS' EQUITY - Reconciliation of Number of Shares of Common Stock (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Common Stock Issued [Roll Forward]
Balance, beginning of period	668,132	667,046	665,239
Exercise of stock options and issuance of restricted shares	1,591	1,086	1,807
Balance, end of period	669,723	668,132	667,046
Treasury Stock [Roll Forward]
Balance, beginning of period	225,687	207,633	197,453
Exercise of stock options	(2,013)	(1,236)	(3,281)
Balance, end of period	245,343	225,687	207,633
Shares outstanding, end of period	424,380	442,445	459,413
Treasury Stock
Treasury Stock [Roll Forward]
Stock acquired in open market, shares	21,179	19,660	13,212
Other purchases	247	157	222
Shares issued to AFL Stock Plan	(1,209)	(1,251)	(1,365)
Exercise of stock options	(465)	(391)	(1,734)
Other dispositions	(96)	(121)	(155)

SHAREHOLDERS' EQUITY - Anti-Dil

SHAREHOLDERS' EQUITY - Anti-Dilutive Share-Based Awards Excluded from Calculation of Diluted Earnings Per Share (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stockholders' Equity Note [Abstract]
Anti-dilutive share-based awards	1,862	1,215	2,198

SHAREHOLDERS' EQUITY - Weighted

SHAREHOLDERS' EQUITY - Weighted-Average Shares Used in Calculating Earnings Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stockholders' Equity Note [Abstract]
Weighted-average outstanding shares used for calculating basic EPS	430,654	451,204	464,502
Dilutive effect of share-based awards	2,518	2,796	2,906
Weighted-average outstanding shares used for calculating diluted EPS	433,172	454,000	467,408

SHAREHOLDERS' EQUITY - Changes

SHAREHOLDERS' EQUITY - Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	[1]	$ 1,979	$ (563)	$ 2,715
Other comprehensive income loss before reclassifications net of tax	[1]	(1,314)	2,578	(3,247)
Amounts reclassified from accumulated other comprehensive income net of tax	[1]	(40)	(36)	(31)
Other comprehensive income (loss), net of income taxes	[1]	(1,354)	2,542	(3,278)
Balance, end of period	[1]	625	1,979	(563)
Unrealized foreign currency translation gains (losses)
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	[1]	(2,541)	(1,505)	333
Other comprehensive income loss before reclassifications net of tax	[1]	345	(1,036)	(1,833)
Amounts reclassified from accumulated other comprehensive income net of tax	[1]	0	0	(5)
Other comprehensive income (loss), net of income taxes	[1]	345	(1,036)	(1,838)
Balance, end of period	[1]	(2,196)	(2,541)	(1,505)
Unrealized gains (losses) on investment securities
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	[1]	4,672	1,035	2,570
Other comprehensive income loss before reclassifications net of tax	[1]	(1,646)	3,672	(1,499)
Amounts reclassified from accumulated other comprehensive income net of tax	[1]	(40)	(35)	(36)
Other comprehensive income (loss), net of income taxes	[1]	(1,686)	3,637	(1,535)
Balance, end of period	[1]	2,986	4,672	1,035
Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	[1]	(26)	(12)	(5)
Other comprehensive income loss before reclassifications net of tax	[1]	0	(14)	(7)
Amounts reclassified from accumulated other comprehensive income net of tax	[1]	0	0	0
Other comprehensive income (loss), net of income taxes	[1]	0	(14)	(7)
Balance, end of period	[1]	(26)	(26)	(12)
Pension liability adjustment
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	[1]	(126)	(81)	(183)
Other comprehensive income loss before reclassifications net of tax	[1]	(13)	(44)	92
Amounts reclassified from accumulated other comprehensive income net of tax	[1]	0	(1)	10
Other comprehensive income (loss), net of income taxes	[1]	(13)	(45)	102
Balance, end of period	[1]	$ (139)	$ (126)	$ (81)
[1]	All amounts in the table above are net of tax.

SHAREHOLDERS' EQUITY - Reclassi

SHAREHOLDERS' EQUITY - Reclassifications Out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Sales and redemptions										$ 303	$ 215	$ 262
Other-than-temporary impairment losses realized	[1]									(153)	(31)	(199)
Total before tax		$ 1,110	$ 864	$ 874	$ 1,013	$ 1,075	$ 1,074	$ 1,238	$ 1,104	3,862	4,491	4,816
Income Tax (Expense) Benefit		$ (380)	$ (297)	$ (301)	$ (350)	$ (372)	$ (368)	$ (428)	$ (372)	(1,329)	(1,540)	(1,658)
Net of tax										$ 2,533	$ 2,951	$ 3,158
The expected U.S. tax rate										35.00%	35.00%	35.00%
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net of tax										$ 40	$ 36	$ 31
Reclassification out of Accumulated Other Comprehensive Income | Unrealized gains (losses) on investment securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Sales and redemptions										214	57	255
Other-than-temporary impairment losses realized										(153)	(3)	(199)
Total before tax										61	54	56
Income Tax (Expense) Benefit	[2]									(21)	(19)	(20)
Net of tax										40	35	36
Reclassification out of Accumulated Other Comprehensive Income | Pension liability adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Acquisition and operating expense, actuarial gains (losses)	[3]									(17)	(15)	(19)
Acquisition and operating expenses, prior service (cost) credit	[3]									17	17	4
Income Tax (Expense) Benefit	[2]									0	(1)	5
Net of tax										$ 0	$ 1	(10)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized foreign currency translation gains (losses)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Sales and redemptions												7
Income Tax (Expense) Benefit	[2]											(2)
Net of tax												$ 5
[1]	Includes $131 and $45 for the years ended December 31, 2015 and 2013, respectively, for credit-related impairments; $26 for the year ended December 31, 2013 for impairments due to severity and duration of decline in fair value; and $22, $31 and $128 for the years ended December 31, 2015, 2014 and 2013, respectively, from change in intent to sell securities
[2]	Based on 35% tax rate
[3]	These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 14 for additional details).

SHARE-BASED COMPENSATION - Addi

SHARE-BASED COMPENSATION - Additional Information (Detail) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)plan$ / sharesshares	Dec. 31, 2014$ / sharesshares	Dec. 31, 2013$ / sharesshares	Dec. 31, 2012shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment award, options, grants in period, weighted average grant date fair value | $ / shares	$ 9.46	$ 16.24	$ 14.25
Number of long-term incentive compensation plans | plan	2
Closing common stock price | $ / shares	$ 59.90
Aggregate intrinsic value of stock options outstanding	$ 76
Options Outstanding - Weighted-Average Remaining Term (Yrs)	4 years 6 months
Aggregate intrinsic value of stock options exercisable	$ 72
Weighted-average remaining term of stock options exercisable (in years)	3 years 3 months 18 days
Stock Option Plan Effective Until February 2007 Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option plan, term (in years)	10 years
Second Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years
Stock option plan, vesting period	3 years
Shares available for future grants under the long-term incentive plan | shares	10,100
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation cost not yet recognized, restricted stock awards	$ 44
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | shares	1,815	1,880	1,671	1,363
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year 1 month 6 days
Performance Based Vesting Condition Member | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation cost not yet recognized, restricted stock awards	$ 20
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | shares	849

SHARE-BASED COMPENSATION - Expe

SHARE-BASED COMPENSATION - Expense Recognized in Connection with Share-Based Awards (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Earnings before income taxes	$ 1,110	$ 864	$ 874	$ 1,013	$ 1,075	$ 1,074	$ 1,238	$ 1,104	$ 3,862	$ 4,491	$ 4,816
Net earnings									$ 2,533	$ 2,951	$ 3,158
Net earnings per share:
Basic (in dollars per share)	$ 1.72	$ 1.32	$ 1.33	$ 1.52	$ 1.57	$ 1.56	$ 1.79	$ 1.61	$ 5.88	$ 6.54	$ 6.80
Diluted (in dollars per share)	$ 1.71	$ 1.32	$ 1.32	$ 1.51	$ 1.57	$ 1.56	$ 1.78	$ 1.60	$ 5.85	$ 6.50	$ 6.76
Share Based Compensation Expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Earnings from continuing operations									$ 39	$ 41	$ 37
Earnings before income taxes									39	41	37
Net earnings									$ 27	$ 28	$ 25
Net earnings per share:
Basic (in dollars per share)									$ 0.06	$ 0.06	$ 0.05
Diluted (in dollars per share)									$ 0.06	$ 0.06	$ 0.05

SHARE-BASED COMPENSATION - Assu

SHARE-BASED COMPENSATION - Assumptions Used in Valuing Options Granted (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected term (years)	6 years 3 months 18 days	6 years 3 months 18 days	6 years 6 months 30 days
Expected volatility	20.00%	30.00%	34.00%
Annual forfeiture rate	2.80%	2.70%	1.60%
Risk-free interest rate	2.00%	2.80%	1.80%
Dividend yield	2.70%	2.30%	2.60%

SHARE-BASED COMPENSATION - Stoc

SHARE-BASED COMPENSATION - Stock Option Activity (Detail) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock Option Shares
Beginning Balance	9,307	9,980	12,737
Granted	855	678	703
Canceled	231	115	179
Exercised	(2,013)	(1,236)	(3,281)
Ending Balance	7,918	9,307	9,980
Weighted-Average Exercise Price Per Share
Beginning Balance	$ 48.84	$ 47.03	$ 45
Granted	61.47	61.81	52.86
Canceled	55.70	52.01	44.79
Exercised	45.15	41.04	40.52
Ending Balance	$ 50.94	$ 48.84	$ 47.03

SHARE-BASED COMPENSATION - Shar

SHARE-BASED COMPENSATION - Shares Exercisable (Detail) - shares shares in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares exercisable, end of year	6,085	7,497	8,042

SHARE-BASED COMPENSATION - S116

SHARE-BASED COMPENSATION - Stock Options Outstanding and Exercisable (Detail) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Per Share - Lower Range	$ 14.99
Range of Exercise Prices Per Share - Upper Range	$ 67.67
Options Outstanding - Stock Option Shares	7,918	9,307	9,980	12,737
Options Outstanding - Weighted-Average Remaining Term (Yrs)	4 years 6 months
Options Outstanding - Weighted-Average Exercise Price Per Share	$ 50.94	$ 48.84	$ 47.03	$ 45
Options Exercisable - Stock Option Shares	6,085	7,497	8,042
Options Exercisable - Weighted-Average Exercise Price Per Share	$ 48.45
$14.99 - $43.07
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Per Share - Lower Range	14.99
Range of Exercise Prices Per Share - Upper Range	$ 43.07
Options Outstanding - Stock Option Shares	1,651
Options Outstanding - Weighted-Average Remaining Term (Yrs)	3 years 1 month 6 days
Options Outstanding - Weighted-Average Exercise Price Per Share	$ 34.41
Options Exercisable - Stock Option Shares	1,651
Options Exercisable - Weighted-Average Exercise Price Per Share	$ 34.41
$43.28 - $48.56
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Per Share - Lower Range	43.28
Range of Exercise Prices Per Share - Upper Range	$ 48.56
Options Outstanding - Stock Option Shares	1,727
Options Outstanding - Weighted-Average Remaining Term (Yrs)	3 years 2 months 12 days
Options Outstanding - Weighted-Average Exercise Price Per Share	$ 47.05
Options Exercisable - Stock Option Shares	1,723
Options Exercisable - Weighted-Average Exercise Price Per Share	$ 47.05
$49.50 - $57.90
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Per Share - Lower Range	49.50
Range of Exercise Prices Per Share - Upper Range	$ 57.90
Options Outstanding - Stock Option Shares	2,066
Options Outstanding - Weighted-Average Remaining Term (Yrs)	4 years 10 months 12 days
Options Outstanding - Weighted-Average Exercise Price Per Share	$ 54.18
Options Exercisable - Stock Option Shares	1,608
Options Exercisable - Weighted-Average Exercise Price Per Share	$ 55.01
$58.08 - $61.81
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Per Share - Lower Range	58.08
Range of Exercise Prices Per Share - Upper Range	$ 61.81
Options Outstanding - Stock Option Shares	1,628
Options Outstanding - Weighted-Average Remaining Term (Yrs)	5 years 1 month 6 days
Options Outstanding - Weighted-Average Exercise Price Per Share	$ 61.50
Options Exercisable - Stock Option Shares	956
Options Exercisable - Weighted-Average Exercise Price Per Share	$ 61.79
$61.84 - $67.67
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Per Share - Lower Range	61.84
Range of Exercise Prices Per Share - Upper Range	$ 67.67
Options Outstanding - Stock Option Shares	846
Options Outstanding - Weighted-Average Remaining Term (Yrs)	7 years 9 months 18 days
Options Outstanding - Weighted-Average Exercise Price Per Share	$ 62.96
Options Exercisable - Stock Option Shares	147
Options Exercisable - Weighted-Average Exercise Price Per Share	$ 63.96

SHARE-BASED COMPENSATION - Summ

SHARE-BASED COMPENSATION - Summary of Stock Option Activity (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Total intrinsic value of options exercised	$ 36	$ 25	$ 66
Cash received from options exercised	68	39	113
Tax benefit realized as a result of options exercised and restricted stock releases	$ 25	$ 17	$ 30

SHARE-BASED COMPENSATION - Rest

SHARE-BASED COMPENSATION - Restricted Stock Activity (Detail) - Restricted stock - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Shares
Beginning balance	1,880	1,671	1,363
Granted	638	584	782
Canceled	(145)	(27)	(56)
Vested	(558)	(348)	(418)
Ending Balance	1,815	1,880	1,671
Weighted-Average Grant-Date Fair Value Per Share
Beginning balance	$ 54.33	$ 52.12	$ 50.19
Granted	61.51	62.12	52.77
Canceled	57.52	52.66	48.63
Vested	48.41	56.95	47.49
Ending Balance	$ 58.42	$ 54.33	$ 52.12

STATUTORY ACCOUNTING AND DIV119

STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS - Additional Information (Detail) $ in Millions, ¥ in Billions	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2015JPY (¥)
Statutory Accounting Practices [Line Items]
Statutory accounting practices, statutory capital and surplus required	$ 1,300
Net Derivatives Notional Amount	22,127	$ 23,662
Aflac
Statutory Accounting Practices [Line Items]
Capital and surplus, statutory accounting practices of the state or country basis	11,298	10,839
Net Income, Nebraska state basis	2,300	2,400	$ 2,400
Amount available for dividend distribution without prior approval from regulatory agency	2,300
Dividends declared	2,400
Aflac Japan
Statutory Accounting Practices [Line Items]
Capital and surplus, statutory accounting practices of the state or country basis	4,700	$ 5,600
Twenty Fifteen Profit Repatriation
Statutory Accounting Practices [Line Items]
Intercompany transfer profit repatriation additional amount received	$ 71
Foreign currency forwards and options | Twenty Fifteen Profit Repatriation
Statutory Accounting Practices [Line Items]
Net Derivatives Notional Amount | ¥				¥ 242.5
Foreign currency forwards and options | Future profit repatriation
Statutory Accounting Practices [Line Items]
Net Derivatives Notional Amount | ¥				¥ 124.1

STATUTORY ACCOUNTING AND DIV120

STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS - Reconciliation of Capital and Surplus Between Sap and Practices Permitted by the State of Nebraska (Detail) - Aflac - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Statutory Accounting Practices [Line Items]
Capital and surplus, Nebraska state basis	$ 11,298	$ 10,839
Capital and surplus, NAIC basis	10,553	10,803
Lease Deposits
Statutory Accounting Practices [Line Items]
State permitted practice amount	(38)	(36)
Reinsurance
Statutory Accounting Practices [Line Items]
State permitted practice amount	$ (707)	$ 0

STATUTORY ACCOUNTING AND DIV121

STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS - Profits Repatriated by Aflac Japan to Aflac U.S. (Detail) $ in Millions, ¥ in Billions	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2015JPY (¥)	Dec. 31, 2014USD ($)	Dec. 31, 2014JPY (¥)	Dec. 31, 2013USD ($)	Dec. 31, 2013JPY (¥)
Insurance [Abstract]
Profit repatriation	$ 2,139	¥ 259	$ 1,704	¥ 181.4	$ 771	¥ 76.8

BENEFIT PLANS - Additional Info

BENEFIT PLANS - Additional Information (Detail) - USD ($) shares in Millions, $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amount of years left to meet rule of 80 for active employees to be eligible for postretirement medical benefits				5 years
Amount of years left to meet 15 year service requirement for active employees age 55 or older to be eligible for postretirement medical benefits				5 years
Transition obligation		$ 0
Percentage of matching contributions by the Company to employee's contributions to 401(k) plan			50.00%	50.00%
Matching 401(k) plan contributions included in acquisition and operating expenses		$ 9	$ 7	$ 5
Percentage of matching contributions by the Company to employee's contributions to 401(k) plan		50.00%
Shares of employer-issued common stock held for plan participants by plan trustee (in millions)		1
Non-Elective Defined Contribution Percentage of Employee Compensation		2.00%
Lower Limit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Health care plan, retirement age for eligibility, (in years)				55 years
Health care plan, number of years of service for eligibility				15 years
Health care plan, retirement age and years of service combined years for eligibility				80 years
Upper Limit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of matching contributions by the Company to employee's contributions to 401(k) plan		6.00%
Japan Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate - benefit obligations		1.75%	1.75%	2.25%
AA corporate bonds average duration		20 years
Prior service cost (credit)		$ 0	$ 0	$ 0
Defined benefit plan, future amortization of actuarial losses		1
Defined benefit plan, expected contributions to the plan in 2016		$ 20
U.S. Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate - benefit obligations		4.50%	4.50%	4.75%
AA corporate bonds average duration		17 years
Prior service cost (credit)		$ 0	$ 0	$ (4)
Defined benefit plan, future amortization of actuarial losses		13
Defined benefit plan, expected contributions to the plan in 2016		$ 10
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Amendments	$ (51)
Plan amendment remaining amortization period	3 years
Discount rate - benefit obligations	4.75%	4.50%	4.50%	4.75%
Prior service cost (credit)		$ 0	$ 0	$ (51)
Defined benefit plan, future amortization of actuarial losses		1
Defined benefit plan, future amortization of prior service cost (credit)		10
Associate Stock Bonus Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred policy acquisition costs, amount attributable to stock bonus plan		$ 34	$ 36	$ 38

BENEFIT PLANS - Reconciliation

BENEFIT PLANS - Reconciliation of Funded Status of Basic Employee Defined-Benefit Pension Plans (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Japan Pension Plan
Projected benefit obligation:
Benefit obligation, beginning of year		$ 267	$ 270
Service cost		15	15	$ 16
Interest cost		1	9	10
Actuarial (gain) loss		0	21
Benefits and expenses paid		(7)	(9)
Effect of foreign exchange rate changes		0	(39)
Benefit obligation, end of year		276	267	270
Plan assets:
Fair value of plan assets, beginning of year		183	182
Actual return on plan assets		1	12
Employer contributions		21	24
Benefits and expenses paid		(7)	(9)
Effect of foreign exchange rate changes		0	(26)
Fair value of plan assets, end of year		198	183	182
Funded status of the plans	[1]	(78)	(84)
Amounts recognized in accumulated other comprehensive income:
Net actuarial (gain) loss		42	40
Prior service (credit) cost		(2)	(2)
Total included in accumulated other comprehensive income		40	38
Accumulated benefit obligation		244	235
U.S. Pension Plan
Projected benefit obligation:
Benefit obligation, beginning of year		717	601
Service cost		23	20	22
Interest cost		18	38	23
Actuarial (gain) loss		(6)	74
Benefits and expenses paid		(17)	(16)
Effect of foreign exchange rate changes		0	0
Benefit obligation, end of year		735	717	601
Plan assets:
Fair value of plan assets, beginning of year		341	313
Actual return on plan assets		(6)	26
Employer contributions		18	18
Benefits and expenses paid		(17)	(16)
Effect of foreign exchange rate changes		0	0
Fair value of plan assets, end of year		336	341	313
Funded status of the plans	[1]	(399)	(376)
Amounts recognized in accumulated other comprehensive income:
Net actuarial (gain) loss		175	167
Prior service (credit) cost		(4)	(4)
Total included in accumulated other comprehensive income		171	163
Accumulated benefit obligation		621	611
Other Postretirement Benefit Plans, Defined Benefit
Projected benefit obligation:
Benefit obligation, beginning of year		44	46
Service cost		1	1	5
Interest cost		2	2	3
Actuarial (gain) loss		(5)	(3)
Benefits and expenses paid		(2)	(2)
Effect of foreign exchange rate changes		0	0
Benefit obligation, end of year		40	44	46
Plan assets:
Fair value of plan assets, beginning of year		0	0
Actual return on plan assets		0	0
Employer contributions		2	2
Benefits and expenses paid		(2)	(2)
Effect of foreign exchange rate changes		0	0
Fair value of plan assets, end of year		0	0	$ 0
Funded status of the plans	[1]	(40)	(44)
Amounts recognized in accumulated other comprehensive income:
Net actuarial (gain) loss		12	19
Prior service (credit) cost		(11)	(28)
Total included in accumulated other comprehensive income		$ 1	$ (9)
[1]	Recognized in other liabilities in the consolidated balance sheets

BENEFIT PLANS - Weighted-Averag

BENEFIT PLANS - Weighted-Average Actuarial Assumptions (Detail)		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Oct. 31, 2013
Japan Pension Plan
Weighted-average actuarial assumptions:
Discount rate - net periodic benefit cost		1.75%	2.25%	2.25%
Discount rate - benefit obligations		1.75%	1.75%	2.25%
Expected long-term return on plan assets		2.00%	2.00%	2.00%
U.S. Pension Plan
Weighted-average actuarial assumptions:
Discount rate - net periodic benefit cost		4.50%	4.75%	4.25%
Discount rate - benefit obligations		4.50%	4.50%	4.75%
Expected long-term return on plan assets		7.25%	7.50%	7.50%
Rate of compensation increase		4.00%	4.00%	4.00%
Other Postretirement Benefit Plans, Defined Benefit
Weighted-average actuarial assumptions:
Discount rate - net periodic benefit cost		4.50%	4.75%	4.25%
Discount rate - benefit obligations		4.50%	4.50%	4.75%	4.75%
Health care cost trend rates	[1]	5.30%	5.70%	6.40%
Defined benefit plan, ultimate health care cost trend rate		4.50%	4.60%	4.60%
Defined benefit plan number of years that rate reaches ultimate trend rate		78 years	78 years	78 years
[1]	For the years 2015, 2014 and 2013, the health care cost trend rates are expected to trend down to 4.5% in 78 years, 4.6% in 78 years, and 4.6% in 78 years, respectively.

BENEFIT PLANS - One-Percentage

BENEFIT PLANS - One-Percentage Point Increase and Decrease in Assumed Health Care Cost Trend Rates (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Increase in total service and interest costs	$ 0
Increase in postretirement benefit obligation	2
Decrease in total service and interest costs	0
Decrease in postretirement benefit obligation	$ 2

BENEFIT PLANS - Net Periodic (B

BENEFIT PLANS - Net Periodic (Benefit) Cost Included in Acquisition and Operating Expenses (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Japan Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 15	$ 15	$ 16
Interest cost	1	9	10
Expected return on plan assets	(4)	(4)	(3)
Amortization of net actuarial loss	1	1	2
Amortization of prior service cost (credit)	0	0	0
Net periodic (benefit) cost	13	21	25
U.S. Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	23	20	22
Interest cost	18	38	23
Expected return on plan assets	(22)	(20)	(17)
Amortization of net actuarial loss	14	11	15
Amortization of prior service cost (credit)	0	0	0
Net periodic (benefit) cost	33	49	43
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	1	1	5
Interest cost	2	2	3
Expected return on plan assets	0	0	0
Amortization of net actuarial loss	2	3	2
Amortization of prior service cost (credit)	(17)	(17)	(4)
Net periodic (benefit) cost	$ (12)	$ (11)	$ 6

BENEFIT PLANS - Summary of Amou

BENEFIT PLANS - Summary of Amounts Recognized in Other Comprehensive Loss (Income) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Japan Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	$ 3	$ 12	$ (14)
Amortization of net actuarial loss	(1)	(1)	(2)
Prior service cost (credit)	0	0	0
Amortization of prior service cost	0	0	0
Total	2	11	(16)
U.S. Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	22	67	(59)
Amortization of net actuarial loss	(14)	(11)	(15)
Prior service cost (credit)	0	0	(4)
Amortization of prior service cost	0	0	0
Total	8	56	(78)
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	(5)	(3)	(7)
Amortization of net actuarial loss	(2)	(3)	(2)
Prior service cost (credit)	0	0	(51)
Amortization of prior service cost	17	17	4
Total	$ 10	$ 11	$ (56)

BENEFIT PLANS - Expected Benefi

BENEFIT PLANS - Expected Benefit Payments (Detail) $ in Millions	Dec. 31, 2015USD ($)
Japan Pension Plan
Schedule of Postemployment Expected Future Benefit Payments [Line Items]
2,016	$ 12
2,017	7
2,018	7
2,019	9
2,020	10
2021-2025	66
U.S. Pension Plan
Schedule of Postemployment Expected Future Benefit Payments [Line Items]
2,016	21
2,017	22
2,018	23
2,019	24
2,020	25
2021-2025	170
Other Postretirement Benefit Plans, Defined Benefit
Schedule of Postemployment Expected Future Benefit Payments [Line Items]
2,016	2
2,017	3
2,018	3
2,019	3
2,020	4
2021-2025	$ 19

BENEFIT PLANS - Asset Allocatio

BENEFIT PLANS - Asset Allocation Targets (Detail)	12 Months Ended
	Dec. 31, 2015
Japan Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	100.00%
U.S. Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	100.00%
Domestic equity securities | Japan Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	11.00%
Domestic equity securities | U.S. Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	43.00%
International equity securities | Japan Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	15.00%
International equity securities | U.S. Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	22.00%
Fixed income funds | Japan Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	59.00%
Fixed income funds | U.S. Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	35.00%
Other Investments | Japan Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	15.00%
Other Investments | U.S. Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	0.00%

BENEFIT PLANS - Fair Value Hier

BENEFIT PLANS - Fair Value Hierarchy Levels of Funded Pension Plans' Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Japan Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 198	$ 183	$ 182
U.S. Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	336	341	$ 313
U.S. Pension Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	336	341
Japanese equity securities | Japan Pension Plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	22	0
International equity securities | Japan Pension Plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	33	34
Japanese bonds | Japan Pension Plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	71	72
International bonds | Japan Pension Plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	48	44
Insurance contracts | Japan Pension Plan | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	23	22
Cash and cash equivalents | Japan Pension Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1	11
Cash and cash equivalents | U.S. Pension Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1	0
U S large cap equity securities | U.S. Pension Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	94	116
U S mid cap equity securities | U.S. Pension Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	16	14
Real estate equity funds | U.S. Pension Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	10	10
International fund | U.S. Pension Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	77	61
Fixed income funds | U.S. Pension Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	134	136
Aflac Incorporated common stock | U.S. Pension Plan | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 4	$ 4

COMMITMENTS AND CONTINGENT L131

COMMITMENTS AND CONTINGENT LIABILITIES - Additional Information (Detail) ¥ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)agreements	Dec. 31, 2015JPY (¥)
Commitments and Contingencies Disclosure [Line Items]
Number of operating service agreements, technology and consulting	2
Number of operating service agreements, management consulting and technology	1
Middle market loan program commitment | $	$ 182
Number of operating service agreements, information technology and data services	2
Operating Leases, lease terms	expire in various years through 2026	expire in various years through 2026
Mainframe and server computer operations and support
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	5 years	5 years
Outsourcing agreements, aggregate remaining cost	$ 298	¥ 36,000
Technology and consulting company application maintenance and development services
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	2 years	2 years
Outsourcing agreements, aggregate remaining cost	$ 20	¥ 2,400
Management consulting and technology services company application maintenance and development services
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	2 years	2 years
Outsourcing agreements, aggregate remaining cost	$ 26	¥ 3,100
Information technology and data services company application maintenance and development services first agreement
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	1 year	1 year
Outsourcing agreements, aggregate remaining cost	$ 5	¥ 637
Information technology and data services company application maintenance and development services second agreement
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	2 years	2 years
Outsourcing agreements, aggregate remaining cost	$ 13	¥ 1,600

COMMITMENTS AND CONTINGENT L132

COMMITMENTS AND CONTINGENT LIABILITIES - Future Minimum Lease Payments due under Non-Cancelable Operating Leases (Detail) $ in Millions	Dec. 31, 2015USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,016	$ 59
2,017	44
2,018	31
2,019	10
2,020	8
Thereafter	20
Total future minimum lease payments	$ 172

Unaudited Consolidated Quart133

Unaudited Consolidated Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Income Statements, [Line Items]
Net investment income	$ 792	$ 784	$ 777	$ 782	$ 808	$ 841	$ 843	$ 827	$ 3,135	$ 3,319	$ 3,293
Net premium income	4,394	4,380	4,364	4,432	4,489	4,841	4,888	4,854	17,570	19,072	20,135
Realized investment gains (losses)	114	(114)	127	13	143	16	102	(46)
Other income (loss)	19	(10)	19	(1)	74	38	5	5	27	122	112
Total revenues	5,319	5,040	5,287	5,226	5,514	5,736	5,838	5,640	20,872	22,728	23,939
Total benefits and expenses	4,209	4,176	4,413	4,213	4,439	4,662	4,600	4,536	17,010	18,237	19,123
Earnings before income taxes	1,110	864	874	1,013	1,075	1,074	1,238	1,104	3,862	4,491	4,816
Total income tax expense	380	297	301	350	372	368	428	372	$ 1,329	$ 1,540	$ 1,658
Net earnings	$ 730	$ 567	$ 573	$ 663	$ 703	$ 706	$ 810	$ 732
Net earnings per basic share	$ 1.72	$ 1.32	$ 1.33	$ 1.52	$ 1.57	$ 1.56	$ 1.79	$ 1.61	$ 5.88	$ 6.54	$ 6.80
Net earnings per diluted share	$ 1.71	$ 1.32	$ 1.32	$ 1.51	$ 1.57	$ 1.56	$ 1.78	$ 1.60	$ 5.85	$ 6.50	$ 6.76

Schedule II - Aflac Incorporate

Schedule II - Aflac Incorporated (Parent Only) - Condensed Statement of Earnings (Detail) - USD ($) $ in Millions		1 Months Ended	3 Months Ended								12 Months Ended
		Apr. 30, 2015	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Condensed Income Statements, [Line Items]
Net investment income			$ 792	$ 784	$ 777	$ 782	$ 808	$ 841	$ 843	$ 827	$ 3,135		$ 3,319	$ 3,293
Realized investment gains (losses)											140		215	399
Total revenues			5,319	5,040	5,287	5,226	5,514	5,736	5,838	5,640	20,872		22,728	23,939
Interest expense											289		317	293
Other operating expenses											392	[1]	178	193
Earnings before income taxes			1,110	864	874	1,013	1,075	1,074	1,238	1,104	3,862		4,491	4,816
Current tax expense (benefit)											1,288		1,079	1,236
Deferred tax expense (benefit)											41		461	422
Total income tax expense			$ 380	$ 297	$ 301	$ 350	$ 372	$ 368	$ 428	$ 372	1,329		1,540	1,658
Net earnings											2,533		2,951	3,158
Parent Company
Condensed Income Statements, [Line Items]
Dividends from subsidiaries	[2]										2,393		1,483	962
Management and service fees from subsidiaries	[2]										260		272	292
Net investment income											22		13	11
Interest from subsidiaries	[2]										6		6	7
Realized investment gains (losses)											86		45	10
Change in fair value on the cross-currency interest rate swaps											(53)		314	274
Other income											0		(11)	1
Total revenues											2,714		2,122	1,557
Interest expense											231		243	208
Other operating expenses											321		88	79
Total operating expenses											552		331	287
Earnings before income taxes											2,162		1,791	1,270
Current tax expense (benefit)											2		1	0
Deferred tax expense (benefit)											(82)		120	98
Total income tax expense											(80)		121	98
Earnings before equity in undistributed earnings of subsidiaries											2,242		1,670	1,172
Equity in undistributed earnings of subsidiaries	[2]										291		1,281	1,986
Net earnings											2,533		$ 2,951	$ 3,158
8.50% senior notes due May 2019
Condensed Income Statements, [Line Items]
Expense on extinguishment of debt, make-whole premium		$ 230									$ 230
[1]	Includes expense of $230 for the make-whole payment associated with the early extinguishment of debt
[2]	Eliminated in consolidation

Schedule II - Aflac Incorpor135

Schedule II - Aflac Incorporated (Parent Only) - Condensed Statements of Comprehensive Income (Loss) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Net earnings		$ 2,533	$ 2,951	$ 3,158
Foreign currency translation adjustments:
Unrealized foreign currency translation gains (losses) during period - parent only		360	(1,455)	(1,588)
Unrealized gains (losses) on investment securities:
Unrealized holding gains (losses) on investment securities during period - parent only		(2,534)	5,947	(2,362)
Pension liability adjustment during period		(20)	(76)	157
Total other comprehensive income (loss) before income taxes		(2,255)	4,345	(3,859)
Income tax expense (benefit) related to items of other comprehensive income (loss)		(901)	1,803	(581)
Other comprehensive income (loss), net of income taxes	[1]	(1,354)	2,542	(3,278)
Total comprehensive income (loss)		1,179	5,493	(120)
Parent Company
Condensed Financial Statements, Captions [Line Items]
Net earnings		2,533	2,951	3,158
Foreign currency translation adjustments:
Unrealized foreign currency translation gains (losses) during period - parent only		3	39	48
Equity in unrealized foreign currency translation gains (losses) of subsidiaries during period		357	(1,494)	(1,636)
Unrealized gains (losses) on investment securities:
Unrealized holding gains (losses) on investment securities during period - parent only		(8)	9	(12)
Equity in unrealized holding gains (losses) on investment securities held by subsidiaries during period		(2,526)	5,938	(2,350)
Equity in reclassification adjustment for realized (gains) losses of subsidiaries included in net earnings		(61)	(54)	(56)
Unrealized gains (losses) on derivatives during period		0	(17)	(10)
Pension liability adjustment during period		(20)	(76)	157
Total other comprehensive income (loss) before income taxes		(2,255)	4,345	(3,859)
Income tax expense (benefit) related to items of other comprehensive income (loss)		(901)	1,803	(581)
Other comprehensive income (loss), net of income taxes		(1,354)	2,542	(3,278)
Total comprehensive income (loss)		$ 1,179	$ 5,493	$ (120)
[1]	All amounts in the table above are net of tax.

Schedule II - Aflac Incorpor136

Schedule II - Aflac Incorporated (Parent Only) - Condensed Balance Sheet (Detail) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments and cash:
Other investments		$ 294	$ 171
Cash and cash equivalents		4,350	4,658	$ 2,543	$ 2,041
Total investments and cash		105,897	107,341
Other assets	[1]	1,988	2,120
Total assets		118,296	119,767		121,307
Liabilities:
Notes payable		4,991	5,268
Other liabilities	[2]	2,665	4,719
Total liabilities		100,588	101,420
Shareholders' equity:
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2015 and 2014; issued 669,723 shares in 2015 and 668,132 shares in 2014		67	67
Additional paid-in capital		1,828	1,711
Retained earnings		24,007	22,156
Accumulated other comprehensive income (loss):
Unrealized foreign currency translation gains (losses)		(2,196)	(2,541)
Unrealized gains (losses) on investment securities		2,986	4,672
Unrealized gains (losses) on derivatives		(26)	(26)
Pension liability adjustment		(139)	(126)
Treasury stock, at average cost		(8,819)	(7,566)
Total shareholders' equity		17,708	18,347	14,620
Total liabilities and shareholders' equity		118,296	119,767
Parent Company
Investments and cash:
Fixed maturity securities available for sale, at fair value (amortized cost $481 in 2015 and $419 in 2014)		493	437
Investments in subsidiaries	[3]	20,500	21,430
Other investments		9	24
Cash and cash equivalents		1,721	1,638	$ 1,081	$ 830
Total investments and cash		22,723	23,529
Due from subsidiaries	[3]	113	116
Other assets		582	766
Total assets		23,418	24,411
Liabilities:
Income taxes		8	6
Employee benefit plans		274	282
Notes payable		5,008	5,285
Other liabilities		420	491
Total liabilities		5,710	6,064
Shareholders' equity:
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2015 and 2014; issued 669,723 shares in 2015 and 668,132 shares in 2014		67	67
Additional paid-in capital		1,828	1,711
Retained earnings		24,007	22,156
Accumulated other comprehensive income (loss):
Unrealized foreign currency translation gains (losses)		(2,196)	(2,541)
Unrealized gains (losses) on investment securities		2,986	4,672
Unrealized gains (losses) on derivatives		(26)	(26)
Pension liability adjustment		(139)	(126)
Treasury stock, at average cost		(8,819)	(7,566)
Total shareholders' equity		17,708	18,347
Total liabilities and shareholders' equity		$ 23,418	$ 24,411
[1]	Includes $102 in 2015 and $106 in 2014 of derivatives from consolidated variable interest entities
[2]	Includes $293 in 2015 and $318 in 2014 of derivatives from consolidated variable interest entities
[3]	Eliminated in consolidation

Schedule II - Aflac Incorpor137

Schedule II - Aflac Incorporated (Parent Only) - Condensed Balance Sheet Parenthetical (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	1,900,000	1,900,000
Common stock, shares issued (in shares)	669,723	668,132	667,046	665,239
Parent Company
Condensed Financial Statements, Captions [Line Items]
Securities available for sale, fixed maturities, amortized cost	$ 481	$ 419
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	1,900,000	1,900,000
Common stock, shares issued (in shares)	669,723	668,132

Schedule II - Aflac Incorpor138

Schedule II - Aflac Incorporated (Parent Only) - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Millions		1 Months Ended	12 Months Ended
		Apr. 30, 2015	Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net earnings			$ 2,533		$ 2,951	$ 3,158
Adjustments to reconcile net earnings to net cash provided from operating activities:
Change in income tax liabilities			(36)		123	993
Other, net			989	[1]	309	401
Net cash provided (used) by operating activities			6,776		6,550	10,547
Cash flows from investing activities:
Fixed maturity securities sold			3,224		4,178	9,631
Fixed maturity securities purchased			(6,507)		(10,978)	(22,967)
Other investments sold (purchased)			(70)		272	(319)
Settlement of derivatives			(2,119)		(636)	(1,624)
Net cash provided (used) by investing activities			(4,897)		(4,241)	(11,091)
Cash flows from financing activities:
Purchases of treasury stock			(1,315)		(1,210)	(813)
Proceeds from borrowings			998		750	700
Principal payments under debt obligations			(1,272)		(335)	0
Dividends paid to shareholders			(656)		(654)	(635)
Treasury stock reissued			36		33	88
Other, net			(234)	[1]	16	6
Net cash provided (used) by financing activities			(2,187)		(147)	1,136
Net change in cash and cash equivalents			(308)		2,115	502
Cash and cash equivalents, beginning of period			4,658		2,543	2,041
Cash and cash equivalents, end of period			4,350		4,658	2,543
Parent Company
Cash flows from operating activities:
Net earnings			2,533		2,951	3,158
Adjustments to reconcile net earnings to net cash provided from operating activities:
Equity in undistributed earnings of subsidiaries	[2]		(291)		(1,281)	(1,986)
Change in income tax liabilities			6		115	155
Other, net			149	[3]	(72)	11
Net cash provided (used) by operating activities			2,397		1,713	1,338
Cash flows from investing activities:
Fixed maturity securities sold			121		38	8
Fixed maturity securities purchased			(202)		(105)	(206)
Other investments sold (purchased)			14		291	(298)
Settlement of derivatives			147		(1)	0
Additional capitalization of subsidiaries	[2]		(43)		0	0
Net cash provided (used) by investing activities			37		223	(496)
Cash flows from financing activities:
Purchases of treasury stock			(1,315)		(1,210)	(813)
Proceeds from borrowings			998		750	700
Principal payments under debt obligations			(1,272)		(335)	0
Dividends paid to shareholders			(656)		(654)	(635)
Treasury stock reissued			36		33	88
Proceeds from exercise of stock options			47		23	41
Net change in amount due from subsidiary	[2]		43		14	28
Other, net			(232)	[3]	0	0
Net cash provided (used) by financing activities			(2,351)		(1,379)	(591)
Net change in cash and cash equivalents			83		557	251
Cash and cash equivalents, beginning of period			1,638		1,081	830
Cash and cash equivalents, end of period			1,721		$ 1,638	$ 1,081
8.50% senior notes due May 2019
Condensed Cash Flow Statements, Captions [Line Items]
Expense on extinguishment of debt, make-whole premium		$ 230	$ 230
Cash flows from financing activities:
Principal payments under debt obligations		$ (850)
[1]	Operating activities excludes and financing activities includes a cash outflow of $230 for the make-whole payment associated with the early extinguishment of debt
[2]	Eliminated in consolidation
[3]	Operating activities excludes and financing activities includes a cash outflow of $230 for the make-whole payment associated with the early extinguishment of debt

Schedule II - Aflac Incorpor139

Schedule II - Aflac Incorporated (Parent Only) - Summary of Notes Payable (Detail) - USD ($) $ in Millions		Dec. 31, 2015		Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Notes payable		$ 4,991		$ 5,268
Parent Company
Condensed Financial Statements, Captions [Line Items]
Notes payable		5,008		5,285
Parent Company | 3.45% senior notes paid August 2015
Condensed Financial Statements, Captions [Line Items]
Notes payable		0		300
Parent Company | 2.65% senior notes due February 2017
Condensed Financial Statements, Captions [Line Items]
Notes payable	[1]	652		653
Parent Company | 8.50% senior notes due May 2019
Condensed Financial Statements, Captions [Line Items]
Notes payable		0	[2]	850
Parent Company | 2.40% senior notes due March 2020
Condensed Financial Statements, Captions [Line Items]
Notes payable		550		0
Parent Company | 4.00% senior notes due February 2022
Condensed Financial Statements, Captions [Line Items]
Notes payable		350		350
Parent Company | 3.625% senior notes due June 2023
Condensed Financial Statements, Captions [Line Items]
Notes payable		700		700
Parent Company | 3.625% senior notes due November 2024
Condensed Financial Statements, Captions [Line Items]
Notes payable	[3]	749		749
Parent Company | 3.25% senior notes due March 2025
Condensed Financial Statements, Captions [Line Items]
Notes payable		448	[3]	0
Parent Company | 6.90% senior notes due December 2039
Condensed Financial Statements, Captions [Line Items]
Notes payable	[3]	397		397
Parent Company | 6.45% senior notes due August 2040
Condensed Financial Statements, Captions [Line Items]
Notes payable	[3]	448		448
Parent Company | 5.50% subordinated notes due September 2052
Condensed Financial Statements, Captions [Line Items]
Notes payable		500		500
Parent Company | 2.26% yen-denominated Uridashi notes due September 2016
Condensed Financial Statements, Captions [Line Items]
Notes payable		83		83
Parent Company | 1.84% yen-denominated Samurai notes due July 2016
Condensed Financial Statements, Captions [Line Items]
Notes payable		131		131
Parent Company | 3.60% yen-denominated loan paid July 2015
Condensed Financial Statements, Captions [Line Items]
Notes payable		0		83
Parent Company | 3.00% yen-denominated loan paid August 2015
Condensed Financial Statements, Captions [Line Items]
Notes payable		$ 0		$ 41
[1]	Principal amount plus an issuance premium that is being amortized over the life of the notes
[2]	Redeemed in April 2015
[3]	Principal amount net of an issuance discount that is being amortized over the life of the notes

Schedule II - Aflac Incorpor140

Schedule II - Aflac Incorporated (Parent Only) - Summary of Notes Payable Parenthetical (Detail) $ in Millions, ¥ in Billions	Dec. 31, 2015USD ($)	Dec. 31, 2015JPY (¥)	Apr. 30, 2015	Mar. 31, 2015USD ($)	Dec. 31, 2014JPY (¥)	Nov. 30, 2014USD ($)	Jun. 30, 2013USD ($)	Oct. 31, 2012USD ($)	Sep. 30, 2012USD ($)	Jul. 31, 2012USD ($)	Feb. 29, 2012USD ($)	Jul. 31, 2011JPY (¥)	Aug. 31, 2010USD ($)	Dec. 31, 2009USD ($)	May. 31, 2009USD ($)	Sep. 30, 2006JPY (¥)
3.45% senior notes paid August 2015
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate					3.45%
Debt instrument, principal amount													$ 300
2.65% senior notes due February 2017
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	2.65%	2.65%			2.65%					2.65%	2.65%
Debt instrument, principal amount	$ 400									$ 250	$ 400
8.50% senior notes due May 2019
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate			8.50%		8.50%
Debt instrument, principal amount															$ 850
2.40% senior notes due March 2020
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	2.40%	2.40%		2.40%
Debt instrument, principal amount	$ 550			$ 550
4.00% senior notes due February 2022
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	4.00%	4.00%			4.00%						4.00%
Debt instrument, principal amount	$ 350										$ 350
3.625% senior notes due June 2023
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	3.625%	3.625%			3.625%		3.625%
Debt instrument, principal amount	$ 700						$ 700
3.625% senior notes due November 2024
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	3.625%	3.625%			3.625%	3.625%
Debt instrument, principal amount	$ 750					$ 750
3.25% senior notes due March 2025
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	3.25%	3.25%		3.25%
Debt instrument, principal amount	$ 450			$ 450
6.90% senior notes due December 2039
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	6.90%	6.90%			6.90%
Debt instrument, principal amount														$ 400
6.45% senior notes due August 2040
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	6.45%	6.45%			6.45%
Debt instrument, principal amount													$ 450
5.50% subordinated notes due September 2052
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	5.50%	5.50%			5.50%			5.50%	5.50%
Debt instrument, principal amount	$ 500							$ 50	$ 450
2.26% yen-denominated Uridashi notes due September 2016
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	2.26%	2.26%			2.26%
Debt instrument, principal amount | ¥		¥ 8			¥ 8											¥ 10
1.84% yen-denominated Samurai notes due July 2016
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	1.84%	1.84%			1.84%							1.84%
Debt instrument, principal amount | ¥		¥ 15.8			¥ 15.8							¥ 15.8
3.60% yen-denominated loan paid July 2015
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate					3.60%
Debt instrument, principal amount | ¥					¥ 10
3.00% yen-denominated loan paid August 2015
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate					3.00%
Debt instrument, principal amount | ¥					¥ 5
Parent Company | 3.45% senior notes paid August 2015
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate					3.45%
Parent Company | 2.65% senior notes due February 2017
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	2.65%	2.65%			2.65%
Parent Company | 8.50% senior notes due May 2019
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate					8.50%
Parent Company | 2.40% senior notes due March 2020
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	2.40%	2.40%
Parent Company | 4.00% senior notes due February 2022
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	4.00%	4.00%			4.00%
Parent Company | 3.625% senior notes due June 2023
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	3.625%	3.625%			3.625%
Parent Company | 3.625% senior notes due November 2024
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	3.625%	3.625%			3.625%
Parent Company | 3.25% senior notes due March 2025
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	3.25%	3.25%
Parent Company | 6.90% senior notes due December 2039
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	6.90%	6.90%			6.90%
Parent Company | 6.45% senior notes due August 2040
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	6.45%	6.45%			6.45%
Parent Company | 5.50% subordinated notes due September 2052
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	5.50%	5.50%			5.50%
Parent Company | 2.26% yen-denominated Uridashi notes due September 2016
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	2.26%	2.26%			2.26%
Debt instrument, principal amount | ¥		¥ 10			¥ 10
Parent Company | 1.84% yen-denominated Samurai notes due July 2016
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	1.84%	1.84%			1.84%
Debt instrument, principal amount | ¥		¥ 15.8			¥ 15.8
Parent Company | 3.60% yen-denominated loan paid July 2015
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	3.60%	3.60%			3.60%
Debt instrument, principal amount | ¥		¥ 10			¥ 10
Parent Company | 3.00% yen-denominated loan paid August 2015
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate	3.00%	3.00%			3.00%
Debt instrument, principal amount | ¥		¥ 5			¥ 5

Schedule II - Aflac Incorpor141

Schedule II - Aflac Incorporated (Parent Only) - Additional Information (Detail) ¥ in Billions	12 Months Ended
	Dec. 31, 2009JPY (¥)
Parent Company | Yen Denominated Uridashi and Samurai Notes
Condensed Financial Statements, Captions [Line Items]
Extinguishment of notes	¥ 2

Schedule II - Aflac Incorpor142

Schedule II - Aflac Incorporated - Aggregate Contractual Maturities of Notes Payable (Detail) $ in Millions	Dec. 31, 2015USD ($)
Condensed Financial Statements, Captions [Line Items]
2,016	$ 203
2,017	655
2,018	4
2,019	3
2,020	551
Thereafter	3,601
Total	5,017
Parent Company
Condensed Financial Statements, Captions [Line Items]
2,016	214
2,017	650
2,018	0
2,019	0
2,020	550
Thereafter	3,600
Total	$ 5,014

Schedule II - Aflac Incorpor143

Schedule II - Aflac Incorporated (Parent Only) - Supplemental Disclosure of Cash Flow Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid	$ 236	$ 241	$ 210
Shareholder dividend reinvestment
Condensed Cash Flow Statements, Captions [Line Items]
Treasury stock issued for shareholder dividend reinvestment	26	26	25
Parent Company
Condensed Cash Flow Statements, Captions [Line Items]
Interest paid	235	241	205
Parent Company | Shareholder dividend reinvestment
Condensed Cash Flow Statements, Captions [Line Items]
Treasury stock issued for shareholder dividend reinvestment	$ 26	$ 26	$ 25

SCHEDULE III SUPPLEMENTARY I144

SCHEDULE III SUPPLEMENTARY INSURANCE INFORMATION - (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	$ 8,511				$ 8,273				$ 8,511	$ 8,273
Future Policy Benefits & Unpaid Policy Claims	73,489				69,276				73,489	69,276
Unearned premiums	7,857				8,626				7,857	8,626
Other policyholders' funds	6,285				6,031				6,285	6,031
Premiums Earned, Net	4,394	$ 4,380	$ 4,364	$ 4,432	4,489	$ 4,841	$ 4,888	$ 4,854	17,570	19,072	$ 20,135
Net investment income	792	$ 784	$ 777	$ 782	808	$ 841	$ 843	$ 827	3,135	3,319	3,293
Benefits and claims, net									11,746	12,937	13,813
Amortization of deferred policy acquisition costs									1,066	1,108	1,074
Other Operating Expenses									4,198	4,192	4,236
Premiums Written									17,083	18,550	21,104
Aflac Japan
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	5,370				5,211				5,370	5,211	5,819
Future Policy Benefits & Unpaid Policy Claims	64,437				60,036				64,437	60,036
Unearned premiums	7,739				8,509				7,739	8,509
Other policyholders' funds	6,285				6,030				6,285	6,030
Premiums Earned, Net									12,046	13,861	14,982
Net investment income									2,436	2,662	2,651
Benefits and claims, net									8,705	10,084	10,924
Amortization of deferred policy acquisition costs									578	649	641
Other Operating Expenses									2,055	2,364	2,495
Premiums Written									11,740	13,352	15,960
Aflac U.S.
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	3,141				3,062				3,141	3,062	2,979
Future Policy Benefits & Unpaid Policy Claims	9,696				9,239				9,696	9,239
Unearned premiums	118				117				118	117
Other policyholders' funds	0				0				0	0
Premiums Earned, Net									5,347	5,211	5,153
Net investment income									678	645	632
Benefits and claims, net									2,873	2,853	2,889
Amortization of deferred policy acquisition costs									488	459	433
Other Operating Expenses									1,570	1,474	1,431
Premiums Written									5,343	5,198	5,144
All other
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	0				0				0	0
Future Policy Benefits & Unpaid Policy Claims	43				1				43	1
Unearned premiums	0				0				0	0
Other policyholders' funds	0				$ 1				0	1
Premiums Earned, Net									177	0	0
Net investment income									21	12	10
Benefits and claims, net									168	0	0
Amortization of deferred policy acquisition costs									0	0	0
Other Operating Expenses									573	354	310
Premiums Written									0	$ 0	$ 0
Intercompany eliminations
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	0								0
Future Policy Benefits & Unpaid Policy Claims	(687)								(687)
Unearned premiums	0								0
Other policyholders' funds	$ 0								$ 0

SCHEDULE IV REINSURANCE Schedul

SCHEDULE IV REINSURANCE Schedule IV - Reinsurance (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	$ 146,610				$ 144,374				$ 146,610	$ 144,374	$ 157,022
Ceded to Other Companies	3,547				3,298				3,547	3,298	3,245
Assumed from Other Companies	0				0				0	0	0
Net Amount	$ 143,063				$ 141,076				$ 143,063	$ 141,076	$ 153,777
Percentage of Amount Assumed to Net	0.00%				0.00%				0.00%	0.00%	0.00%
Gross amount									$ 17,904	$ 19,412	$ 20,233
Ceded to Other Companies									520	350	110
Assumed from Other companies									186	10	12
Net Amount	$ 4,394	$ 4,380	$ 4,364	$ 4,432	$ 4,489	$ 4,841	$ 4,888	$ 4,854	$ 17,570	$ 19,072	$ 20,135
Percentage of Amount Assumed to Net									1.00%	0.00%	0.00%
Health insurance
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross amount									$ 13,604	$ 14,648	$ 15,393
Ceded to Other Companies									509	339	98
Assumed from Other companies									186	10	12
Net Amount									$ 13,281	$ 14,319	$ 15,307
Percentage of Amount Assumed to Net									1.00%	0.00%	0.00%
Life insurance
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross amount									$ 4,300	$ 4,764	$ 4,840
Ceded to Other Companies									11	11	12
Assumed from Other companies									0	0	0
Net Amount									$ 4,289	$ 4,753	$ 4,828
Percentage of Amount Assumed to Net									0.00%	0.00%	0.00%