INVESTMENTS - Recognition and Measurement of OTTI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
OTTI on Investments disclosures
Total OTTI losses recognized during the period	$ 0	$ 3	$ 0	$ 4
Less: portion of impairment loss recognized in AOCI (before taxes)	0	0	0	0
Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell	0	3	0	4
Impairment losses recognized in earnings for 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	115	32	579
Total impairment losses recognized in earnings	20	118	32	583
Securities available-for-sale (AFS)
OTTI on Investments disclosures
Total OTTI losses recognized during the period	0	2	0	3
Less: portion of impairment loss recognized in AOCI (before taxes)	0	0	0	0
Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell	0	2	0	3
Impairment losses recognized in earnings for 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	28	31	223
Total impairment losses recognized in earnings	20	30	31	226
Held-to-maturity securities
OTTI on Investments disclosures
Total OTTI losses recognized during the period	0	1	0	1
Less: portion of impairment loss recognized in AOCI (before taxes)	0	0	0	0
Net impairment losses recognized in earnings for securities that the Company does not intend to sell nor will likely be required to sell	0	1	0	1
Impairment losses recognized in earnings for 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	17	1	24
Total impairment losses recognized in earnings	0	18	1	25
Other assets
OTTI on Investments disclosures
Total OTTI 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 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 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	70	0	332
Total impairment losses recognized in earnings	$ 0	$ 70	$ 0	332
VENEZUELA | Securities available-for-sale (AFS)
OTTI on Investments disclosures
Total impairment losses recognized in earnings				$ 160