INCOME TAXES - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at the beginning of the year	$ 62	$ 72	$ 33
Gross decrease for tax positions related to prior years	(19)	(6)	0
Gross increase for tax positions related to prior years	1	0	60
Decreases for tax positions as a result of the lapse of the statutes of limitations	(2)	(3)	(1)
Decreases for tax positions related to settlements with taxing authorities	0	(1)	(20)
Balance at end of year	$ 42	$ 62	$ 72