SHAREHOLDERS' EQUITY - Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	[1]	$ 1,979	$ (563)	$ 2,715
Other comprehensive income loss before reclassifications net of tax	[1]	(1,314)	2,578	(3,247)
Amounts reclassified from accumulated other comprehensive income net of tax	[1]	(40)	(36)	(31)
Other comprehensive income (loss), net of income taxes	[1]	(1,354)	2,542	(3,278)
Balance, end of period	[1]	625	1,979	(563)
Unrealized foreign currency translation gains (losses)
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	[1]	(2,541)	(1,505)	333
Other comprehensive income loss before reclassifications net of tax	[1]	345	(1,036)	(1,833)
Amounts reclassified from accumulated other comprehensive income net of tax	[1]	0	0	(5)
Other comprehensive income (loss), net of income taxes	[1]	345	(1,036)	(1,838)
Balance, end of period	[1]	(2,196)	(2,541)	(1,505)
Unrealized gains (losses) on investment securities
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	[1]	4,672	1,035	2,570
Other comprehensive income loss before reclassifications net of tax	[1]	(1,646)	3,672	(1,499)
Amounts reclassified from accumulated other comprehensive income net of tax	[1]	(40)	(35)	(36)
Other comprehensive income (loss), net of income taxes	[1]	(1,686)	3,637	(1,535)
Balance, end of period	[1]	2,986	4,672	1,035
Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	[1]	(26)	(12)	(5)
Other comprehensive income loss before reclassifications net of tax	[1]	0	(14)	(7)
Amounts reclassified from accumulated other comprehensive income net of tax	[1]	0	0	0
Other comprehensive income (loss), net of income taxes	[1]	0	(14)	(7)
Balance, end of period	[1]	(26)	(26)	(12)
Pension liability adjustment
Accumulated Other Comprehensive Income [Roll Forward]
Balance, beginning of period	[1]	(126)	(81)	(183)
Other comprehensive income loss before reclassifications net of tax	[1]	(13)	(44)	92
Amounts reclassified from accumulated other comprehensive income net of tax	[1]	0	(1)	10
Other comprehensive income (loss), net of income taxes	[1]	(13)	(45)	102
Balance, end of period	[1]	$ (139)	$ (126)	$ (81)

[1] All amounts in the table above are net of tax.