INCOME TAXES - Uncertain Tax Positions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Uncertain Tax Positions
Balance at the beginning of the period	$ 39	$ 46
Current year tax positions: Additions	10	9
Current year tax positions: Reductions		(1)
Prior year tax positions: Additions	1	1
Prior year tax positions: Reductions	(1)	(5)
Settlements with tax authorities		(1)
Lapse of applicable statute of limitations	(6)	(10)
Balance at the end of the period	$ 43	$ 39