INVESTMENTS - Fair Value of AFS Securities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Fair value
Less than 12 months	$ 82,905	$ 68,298
12 months or longer	33,848	98,800
Total	116,753	167,098
Gross unrealized losses
Less than 12 months	1,037	861
12 months or longer	1,495	2,933
Total	2,532	3,794
U.S. government-sponsored agency guaranteed
Fair value
Less than 12 months	16,690	8,602
12 months or longer	8,484	9,734
Total	25,174	18,336
Gross unrealized losses
Less than 12 months	255	86
12 months or longer	687	648
Total	942	734
Residential
Fair value
Less than 12 months	375	352
12 months or longer	216	34
Total	591	386
Gross unrealized losses
Less than 12 months	1	1
12 months or longer	1	2
Total	2	3
Commercial
Fair value
Less than 12 months	0	0
12 months or longer	1	0
Total	1	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	17,065	8,954
12 months or longer	8,701	9,768
Total	25,766	18,722
Gross unrealized losses
Less than 12 months	256	87
12 months or longer	688	650
Total	944	737
U.S. Treasury
Fair value
Less than 12 months	13,660	11,851
12 months or longer	1,710	57,669
Total	15,370	69,520
Gross unrealized losses
Less than 12 months	166	113
12 months or longer	98	1,269
Total	264	1,382
U.S. Treasury and federal agency securities
Fair value
Less than 12 months	13,660	11,851
12 months or longer	1,710	57,669
Total	15,370	69,520
Gross unrealized losses
Less than 12 months	166	113
12 months or longer	98	1,269
Total	264	1,382
State and municipal
Fair value
Less than 12 months	855	906
12 months or longer	335	324
Total	1,190	1,230
Gross unrealized losses
Less than 12 months	72	17
12 months or longer	31	74
Total	103	91
Foreign government
Fair value
Less than 12 months	49,384	42,250
12 months or longer	19,719	29,176
Total	69,103	71,426
Gross unrealized losses
Less than 12 months	487	540
12 months or longer	600	835
Total	1,087	1,375
Corporate
Fair value
Less than 12 months	455	2,319
12 months or longer	2,444	1,619
Total	2,899	3,938
Gross unrealized losses
Less than 12 months	45	103
12 months or longer	77	105
Total	122	208
Asset-backed securities
Fair value
Less than 12 months	388	154
12 months or longer	0	16
Total	388	170
Gross unrealized losses
Less than 12 months	11	0
12 months or longer	0	0
Total	11	0
Other debt securities
Fair value
Less than 12 months	1,098	1,864
12 months or longer	939	228
Total	2,037	2,092
Gross unrealized losses
Less than 12 months	0	1
12 months or longer	1	0
Total	$ 1	$ 1