INVESTMENTS - Recognition and Measurement of OTTI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
OTTI on Investments disclosures
Total OTTI losses recognized during the period	$ 2	$ 0	$ 2
Less: portion of impairment loss recognized in AOCI (before taxes)	0	0	0
Net impairment losses recognized in earnings for debt securities that the Company does not intend to sell nor will likely be required to sell	2	0	2
Impairment losses recognized in earnings for debt securities that the Company intends to sell, would be more-likely-than-not required to sell or will be subject to an issuer call deemed probable of exercise	21	125	61
Total OTTI losses recognized in earnings	23	125	63
Debt securities available-for-sale (AFS)
OTTI on Investments disclosures
Total OTTI losses recognized during the period	1	0	2
Less: portion of impairment loss recognized in AOCI (before taxes)	0	0	0
Net impairment losses recognized in earnings for debt securities that the Company does not intend to sell nor will likely be required to sell	1	0	2
Impairment losses recognized in earnings for debt securities that the Company intends to sell, would be more-likely-than-not required to sell or will be subject to an issuer call deemed probable of exercise	20	125	59
Total OTTI losses recognized in earnings	21	125	61
Held-to-maturity Securities
OTTI on Investments disclosures
Total OTTI losses recognized during the period	0	0	0
Less: portion of impairment loss recognized in AOCI (before taxes)	0	0	0
Net impairment losses recognized in earnings for debt securities that the Company does not intend to sell nor will likely be required to sell	0	0	0
Impairment losses recognized in earnings for debt securities that the Company intends to sell, would be more-likely-than-not required to sell or will be subject to an issuer call deemed probable of exercise	0	0	2
Total OTTI losses recognized in earnings	0	0	2
Other assets
OTTI on Investments disclosures
Total OTTI losses recognized during the period	1	0	0
Less: portion of impairment loss recognized in AOCI (before taxes)	0	0	0
Net impairment losses recognized in earnings for debt securities that the Company does not intend to sell nor will likely be required to sell	1	0	0
Impairment losses recognized in earnings for debt securities that the Company intends to sell, would be more-likely-than-not required to sell or will be subject to an issuer call deemed probable of exercise	1	0	0
Total OTTI losses recognized in earnings	$ 2	$ 0	$ 0