INVESTMENTS - Debt Securities in HTM in Unrecognized Loss Position (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Fair Value
Less than 12 months	$ 8,840	$ 17,814
12 months or longer	4,072	19,328
Total	12,912	37,142
Gross Unrecognized Losses
Less than 12 months	18	190
12 months or longer	83	663
Total	101	853
Unrealized loss, other than temporary impairment, not credit loss, recorded in AOCI	(623)	(653)
Mortgage-backed securities
Fair Value
Less than 12 months	2,816	2,822
12 months or longer	2,448	18,086
Total	5,264	20,908
Gross Unrecognized Losses
Less than 12 months	8	20
12 months or longer	20	559
Total	28	579
State and municipal securities
Fair Value
Less than 12 months	25	981
12 months or longer	1,050	1,242
Total	1,075	2,223
Gross Unrecognized Losses
Less than 12 months	0	34
12 months or longer	14	104
Total	14	138
Foreign government
Fair Value
Less than 12 months	1,907	1,003
12 months or longer	0	0
Total	1,907	1,003
Gross Unrecognized Losses
Less than 12 months	1	24
12 months or longer	0	0
Total	1	24
Asset-backed securities
Fair Value
Less than 12 months	4,092	13,008
12 months or longer	574	0
Total	4,666	13,008
Gross Unrecognized Losses
Less than 12 months	9	112
12 months or longer	49	0
Total	$ 58	$ 112