INVESTMENTS - Overview (Details) - USD ($) $ in Millions		1 Months Ended		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Jun. 30, 2022	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Investment Holdings
Total investments		$ 508,016		$ 508,016		$ 508,016		$ 512,822
Interest and dividends on investments
Taxable interest				2,714	$ 1,777	7,001	$ 5,152
Interest exempt from U.S. federal income tax				220	73	263	196
Dividend income				59	35	149	107
Total interest and dividend income on investments				2,993	1,885	7,413	5,455
Gross realized investments losses, excluding losses from other-than-temporary impairment
Gross realized investment gains				102	142	282	757
Gross realized investment losses				(50)	(25)	(208)	(102)
Net realized gains (losses) on sales of investments				52	117	74	655
Debt securities AFS
Allowance for credit losses		1	$ 6	1	$ 6	1	6	8	$ 5	$ 5
Fair value		232,143		232,143		232,143		288,522
Transfer of investment securities from AFS to HTM	[1],[2]					21,688	$ 0
Debt securities available-for-sale (AFS)
Investment Holdings
Total investments		232,143		232,143		232,143		288,522
Debt securities held-to-maturity (HTM)
Investment Holdings
Total investments		267,864		267,864		267,864		216,963
Mortgage-backed securities - U.S. government-sponsored agency guaranteed
Debt securities AFS
Amortized cost		12,214		12,214		12,214		33,064
Gross unrealized gains		7		7		7		453
Gross unrealized losses		890		890		890		301
Allowance for credit losses		0		0		0		0
Fair value		11,331		11,331		11,331		33,216
Transfer of investment securities from AFS to HTM			21,500
Securities transferred from AFS to HTM, unrealized loss position			$ 2,300
Residential mortgages
Debt securities AFS
Amortized cost		479		479		479		380
Gross unrealized gains		0		0		0		1
Gross unrealized losses		3		3		3		1
Allowance for credit losses		0		0		0		0
Fair value		476		476		476		380
Commercial
Debt securities AFS
Amortized cost		4		4		4		25
Gross unrealized gains		0		0		0		0
Gross unrealized losses		0		0		0		0
Allowance for credit losses		0		0		0		0
Fair value		4		4		4		25
Mortgage-backed securities
Debt securities AFS
Amortized cost		12,697		12,697		12,697		33,469
Gross unrealized gains		7		7		7		454
Gross unrealized losses		893		893		893		302
Allowance for credit losses		0		0		0		0
Fair value		11,811		11,811		11,811		33,621
U.S. Treasury
Debt securities AFS
Amortized cost		92,595		92,595		92,595		122,669
Gross unrealized gains		41		41		41		615
Gross unrealized losses		2,973		2,973		2,973		844
Allowance for credit losses		0		0		0		0
Fair value		89,663		89,663		89,663		122,440
Agency obligations
Debt securities AFS
Amortized cost		0		0		0		0
Gross unrealized gains		0		0		0		0
Gross unrealized losses		0		0		0		0
Allowance for credit losses		0		0		0		0
Fair value		0		0		0		0
U.S. Treasury and federal agency securities
Debt securities AFS
Amortized cost		92,595		92,595		92,595		122,669
Gross unrealized gains		41		41		41		615
Gross unrealized losses		2,973		2,973		2,973		844
Allowance for credit losses		0		0		0		0
Fair value		89,663		89,663		89,663		122,440
State and municipal
Debt securities AFS
Amortized cost		2,368		2,368		2,368		2,643
Gross unrealized gains		8		8		8		79
Gross unrealized losses		223		223		223		101
Allowance for credit losses		0		0		0		0
Fair value		2,153		2,153		2,153		2,621
Transfer of investment securities from AFS to HTM		165
Securities transferred from AFS to HTM, unrealized loss position		12		12		12
Foreign government
Debt securities AFS
Amortized cost		121,815		121,815		121,815		119,426
Gross unrealized gains		400		400		400		337
Gross unrealized losses		3,244		3,244		3,244		1,023
Allowance for credit losses		0		0		0		0
Fair value		118,971		118,971		118,971		118,740
Corporate
Debt securities AFS
Amortized cost		5,773		5,773		5,773		5,972
Gross unrealized gains		37		37		37		33
Gross unrealized losses		296		296		296		77
Allowance for credit losses		1		1		1		8
Fair value		5,513		5,513		5,513		5,920
Asset-backed securities
Debt securities AFS
Amortized cost		277		277		277		304
Gross unrealized gains		1		1		1		0
Gross unrealized losses		2		2		2		1
Allowance for credit losses		0		0		0		0
Fair value		276		276		276		303
Other debt securities
Debt securities AFS
Amortized cost		3,764		3,764		3,764		4,880
Gross unrealized gains		0		0		0		1
Gross unrealized losses		8		8		8		4
Allowance for credit losses		0		0		0		0
Fair value		3,756		3,756		3,756		4,877
Debt securities AFS
Debt securities AFS
Amortized cost		239,289		239,289		239,289		289,363
Gross unrealized gains		494		494		494		1,519
Gross unrealized losses		7,639		7,639		7,639		2,352
Allowance for credit losses		1		1		1		8
Fair value		232,143		232,143		232,143		288,522
Fair value | Marketable equity securities carried at fair value
Investment Holdings
Total investments		431		431		431		543
Fair value | Non-marketable equity securities
Investment Holdings
Total investments		419		419		419		489
Fair value | Non-marketable securities measured using measurement alternative
Investment Holdings
Total investments		1,690		1,690		1,690		1,413
Non-marketable equity securities measured using the measurement alternative		26		26		26		145
Carried at cost | Non-marketable equity securities
Investment Holdings
Total investments		$ 5,469		$ 5,469		$ 5,469		$ 4,892

[1] Operating and finance lease right-of-use assets and lease liabilities represent non-cash investing and financing activities, respectively, and are not included in the non-cash investing activities presented here. See Note 23 for more information and balances as of September 30, 2022.

[2] See Note 2 for further information on significant disposals.