INVESTMENTS - Fair Value of AFS Securities (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	$ 84,624	$ 74,026
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	759	404
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	18,924	24,821
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	1,192	1,361
Total fair value of available for sale securities that have been in an unrealized loss position	103,548	98,847
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	1,951	1,765
Mortgage-backed securities - U.S. agency-sponsored
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	9,521	4,198
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	85	30
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	2,332	5,547
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	91	129
Total fair value of available for sale securities that have been in an unrealized loss position	11,853	9,745
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	176	159
Mortgage-backed securities - Prime
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	11	5
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	0	0
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	3	2
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	0	0
Total fair value of available for sale securities that have been in an unrealized loss position	14	7
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	0	0
Mortgage-backed securities - Non-U.S. residential
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	2,236	1,276
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	5	3
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	298	199
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	2	4
Total fair value of available for sale securities that have been in an unrealized loss position	2,534	1,475
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	7	7
Mortgage-backed securities - Commercial
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	125	124
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	1	1
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	53	136
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	1	2
Total fair value of available for sale securities that have been in an unrealized loss position	178	260
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	2	3
Mortgage-backed securities
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	11,893	5,603
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	91	34
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	2,686	5,884
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	94	135
Total fair value of available for sale securities that have been in an unrealized loss position	14,579	11,487
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	185	169
U.S. Treasury
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	36,123	36,581
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	263	119
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	1,012	1,013
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	3	8
Total fair value of available for sale securities that have been in an unrealized loss position	37,135	37,594
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	266	127
Agency obligations
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	1,980	5,698
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	8	9
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	49	754
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	1	4
Total fair value of available for sale securities that have been in an unrealized loss position	2,029	6,452
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	9	13
U.S. Treasury and federal agency securities
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	38,103	42,279
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	271	128
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	1,061	1,767
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	4	12
Total fair value of available for sale securities that have been in an unrealized loss position	39,164	44,046
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	275	140
State and municipal securities
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	613	386
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	24	15
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	5,172	5,802
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	898	962
Total fair value of available for sale securities that have been in an unrealized loss position	5,785	6,188
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	922	977
Foreign government
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	24,935	18,495
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	287	147
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	5,339	5,984
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	113	139
Total fair value of available for sale securities that have been in an unrealized loss position	30,274	24,479
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	400	286
Corporate
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	5,731	3,511
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	76	63
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	923	1,350
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	16	28
Total fair value of available for sale securities that have been in an unrealized loss position	6,654	4,861
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	92	91
Asset-backed securities
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	3,149	3,701
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	8	13
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	3,443	3,816
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	25	45
Total fair value of available for sale securities that have been in an unrealized loss position	6,592	7,517
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	33	58
Other debt securities
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	180	0
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	0	0
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	0	0
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	0	0
Total fair value of available for sale securities that have been in an unrealized loss position	180	0
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	0	0
Equity securities
Available for Sale Securities Continuous Unrealized Loss Position
Fair value of available for sale securities that have been in an unrealized loss position for less than twelve months	20	51
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for less than twelve months	2	4
Fair value of available for sale securities that have been in an unrealized loss position for twelve months or longer	300	218
Gross unrealized losses of available for sale securities that have been in an unrealized loss position for twelve months or longer	42	40
Total fair value of available for sale securities that have been in an unrealized loss position	320	269
Total gross unrealized losses of available for sale securities that have been in an unrealized loss position	$ 44	$ 44