INVESTMENTS - Fair Value of AFS Securities (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Fair value
Less than 12 months	$ 138,567	$ 144,333
12 months or longer	53,695	17,829
Total	192,262	162,162
Gross unrealized losses
Less than 12 months	3,997	1,895
12 months or longer	2,607	457
Total	6,604	2,352
Mortgage-backed securities - U.S. government-sponsored agency guaranteed
Fair value
Less than 12 months	7,908	17,039
12 months or longer	3,290	698
Total	11,198	17,737
Gross unrealized losses
Less than 12 months	412	270
12 months or longer	343	31
Total	755	301
Mortgage-backed securities - Residential
Fair value
Less than 12 months	158	96
12 months or longer	1	1
Total	159	97
Gross unrealized losses
Less than 12 months	3	1
12 months or longer	0	0
Total	3	1
Mortgage-backed securities - Commercial
Fair value
Less than 12 months	1	0
12 months or longer	1	0
Total	2	0
Gross unrealized losses
Less than 12 months	0	0
12 months or longer	0	0
Total	0	0
Mortgage-backed securities
Fair value
Less than 12 months	8,067	17,135
12 months or longer	3,292	699
Total	11,359	17,834
Gross unrealized losses
Less than 12 months	415	271
12 months or longer	343	31
Total	758	302
U.S. Treasury
Fair value
Less than 12 months	40,701	56,448
12 months or longer	34,692	6,310
Total	75,393	62,758
Gross unrealized losses
Less than 12 months	1,001	713
12 months or longer	1,491	131
Total	2,492	844
Agency obligations
Fair value
Less than 12 months	0	0
12 months or longer	0	0
Total	0	0
Gross unrealized losses
Less than 12 months	0	0
12 months or longer	0	0
Total	0	0
U.S. Treasury and federal agency securities
Fair value
Less than 12 months	40,701	56,448
12 months or longer	34,692	6,310
Total	75,393	62,758
Gross unrealized losses
Less than 12 months	1,001	713
12 months or longer	1,491	131
Total	2,492	844
State and municipal
Fair value
Less than 12 months	896	229
12 months or longer	707	874
Total	1,603	1,103
Gross unrealized losses
Less than 12 months	31	3
12 months or longer	128	98
Total	159	101
Foreign government
Fair value
Less than 12 months	82,900	64,319
12 months or longer	14,220	9,924
Total	97,120	74,243
Gross unrealized losses
Less than 12 months	2,332	826
12 months or longer	608	197
Total	2,940	1,023
Corporate
Fair value
Less than 12 months	3,082	2,655
12 months or longer	784	22
Total	3,866	2,677
Gross unrealized losses
Less than 12 months	209	77
12 months or longer	37	0
Total	246	77
Asset-backed securities
Fair value
Less than 12 months	708	108
12 months or longer	0	0
Total	708	108
Gross unrealized losses
Less than 12 months	4	1
12 months or longer	0	0
Total	4	1
Other debt securities
Fair value
Less than 12 months	2,213	3,439
12 months or longer	0	0
Total	2,213	3,439
Gross unrealized losses
Less than 12 months	5	4
12 months or longer	0	0
Total	$ 5	$ 4