INCOME TAXES - Uncertain Tax Positions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Uncertain Tax Positions
Balance at the beginning of the period	$ 43	$ 39
Total balance at beginning of the period	53	48
Current year tax positions: Additions	11	10
Current year tax positions: Reductions	1
Prior year tax positions: Additions	1	1
Prior year tax positions: Reductions	(2)	(1)
Lapse of applicable statute of limitations	(6)	(6)
Balance at the end of the period	46	43
Total balance at the end of the period	55	53
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense [Abstract]
Interest and penalties at period start	10	9
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	(1)	1
Interest and penalties at period end	$ 9	$ 10