INVESTMENTS - Debt Securities Held-to-Maturity (Details) - USD ($) $ in Millions	1 Months Ended
Mar. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Debt Securities Held-to-maturity
Carrying value		$ 68,693	$ 63,357
Gross unrealized gains		1,121	386
Gross unrealized losses		154	853
Fair value		69,660	62,890
Mortgage-backed securities - U.S. agency-sponsored
Debt Securities Held-to-maturity
Carrying value		38,885	34,239
Gross unrealized gains		726	199
Gross unrealized losses		80	578
Fair value		39,531	33,860
Mortgage-backed securities - Non-U.S. residential
Debt Securities Held-to-maturity
Carrying value		1,242	1,339
Gross unrealized gains		11	12
Gross unrealized losses		1	1
Fair value		1,252	1,350
Commercial and other
Debt Securities Held-to-maturity
Carrying value		443	368
Gross unrealized gains		0	0
Gross unrealized losses		1	0
Fair value		442	368
Mortgage-backed securities
Debt Securities Held-to-maturity
Carrying value		40,570	35,946
Gross unrealized gains		737	211
Gross unrealized losses		82	579
Fair value		41,225	35,578
Available for sale securities, transfers to held-to-maturity securities fair value	$ 5,000
Available for sale securities, transfers to held-to-maturity securities, unrealized loss	$ 56
State and municipal securities
Debt Securities Held-to-maturity
Carrying value		7,892	7,628
Gross unrealized gains		359	167
Gross unrealized losses		13	138
Fair value		8,238	7,657
Foreign government
Debt Securities Held-to-maturity
Carrying value		1,920	1,027
Gross unrealized gains		17	0
Gross unrealized losses		8	24
Fair value		1,929	1,003
Asset-backed securities
Debt Securities Held-to-maturity
Carrying value		18,311	18,756
Gross unrealized gains		8	8
Gross unrealized losses		51	112
Fair value		$ 18,268	$ 18,652

Available for Sale Securities, Transfers to Held-to-Maturity Securities, Fair Value

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Available for Sale Securities, Transfers to Held-to-Maturity Securities, Unrealized Loss

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Amount of investment in debt security measured at amortized cost (held-to-maturity).

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 45
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Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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