INVESTMENTS - Recognition and Measurement of Impairment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
OTTI on Investments disclosures
Total impairment losses recognized during the period	$ 0	$ 0	$ 0	$ 0
Less: portion of impairment loss recognized in AOCI (before taxes)	0	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	0
Impairment losses recognized in earnings for debt securities that the Company intends to sell, would more-likely-than-not be required to sell or will be subject to an issuer call deemed probable of exercise	19	2	71	5
Total impairment losses recognized in earnings	19	2	71	5
Debt securities available-for-sale (AFS)
OTTI on Investments disclosures
Total impairment losses recognized during the period	0	0	0	0
Less: portion of impairment loss recognized in AOCI (before taxes)	0	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	0
Impairment losses recognized in earnings for debt securities that the Company intends to sell, would more-likely-than-not be required to sell or will be subject to an issuer call deemed probable of exercise	19	2	71	5
Total impairment losses recognized in earnings	19	2	71	5
Debt securities held-to-maturity securities (HTM)
OTTI on Investments disclosures
Total impairment losses recognized during the period		0		0
Less: portion of impairment loss recognized in AOCI (before taxes)		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
Impairment losses recognized in earnings for debt securities that the Company intends to sell, would more-likely-than-not be required to sell or will be subject to an issuer call deemed probable of exercise		0		0
Total impairment losses recognized in earnings		0		0
Other assets
OTTI on Investments disclosures
Total impairment losses recognized during the period	0	0	0	0
Less: portion of impairment loss recognized in AOCI (before taxes)	0	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	0
Impairment losses recognized in earnings for debt securities that the Company intends to sell, would more-likely-than-not be required to sell or will be subject to an issuer call deemed probable of exercise	0	0	0	0
Total impairment losses recognized in earnings	$ 0	$ 0	$ 0	$ 0