SHAREHOLDERS' EQUITY - Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	$ 625	$ 1,979	$ (563)
Other comprehensive income loss before reclassifications net of tax	2,037	(1,314)	2,578
Amounts reclassified from accumulated other comprehensive income net of tax	(32)	(40)	(36)
Other comprehensive income (loss), net of income taxes	2,005	(1,354)	2,542
Balance, end of period	2,630	625	1,979
Unrealized foreign currency translation gains (losses)
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	(2,196)	(2,541)	(1,505)
Other comprehensive income loss before reclassifications net of tax	213	345	(1,036)
Amounts reclassified from accumulated other comprehensive income net of tax	0	0	0
Other comprehensive income (loss), net of income taxes	213	345	(1,036)
Balance, end of period	(1,983)	(2,196)	(2,541)
Unrealized gains (losses) on investment securities
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	2,986	4,672	1,035
Other comprehensive income loss before reclassifications net of tax	1,854	(1,646)	3,672
Amounts reclassified from accumulated other comprehensive income net of tax	(35)	(40)	(35)
Other comprehensive income (loss), net of income taxes	1,819	(1,686)	3,637
Balance, end of period	4,805	2,986	4,672
Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	(26)	(26)	(12)
Other comprehensive income loss before reclassifications net of tax	2	0	(14)
Amounts reclassified from accumulated other comprehensive income net of tax	0	0	0
Other comprehensive income (loss), net of income taxes	2	0	(14)
Balance, end of period	(24)	(26)	(26)
Pension liability adjustment
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	(139)	(126)	(81)
Other comprehensive income loss before reclassifications net of tax	(32)	(13)	(44)
Amounts reclassified from accumulated other comprehensive income net of tax	3	0	(1)
Other comprehensive income (loss), net of income taxes	(29)	(13)	(45)
Balance, end of period	$ (168)	$ (139)	$ (126)