CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Statement of Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCK
Total revenues and other	$ 445	$ 456	$ 1,551	$ 1,095
Total costs and other	492	475	1,448	1,398
Non-operating (loss) income			(230)	581
Income tax benefit				78
NET (LOSS) INCOME	(132)	546	(127)	356
Net income attributable to noncontrolling interest	(1)		(1)
NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCK	$ (133)	$ 546	(128)	356
Reportable Legal Entity | Parent
NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCK
Total revenues and other			22
Total costs and other			168	153
Non-operating (loss) income			(253)	547
Income tax benefit				78
NET (LOSS) INCOME			(399)	472
NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCK			(399)
Reportable Legal Entity | Combined Guarantor Subsidiaries
NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCK
Total revenues and other			1,551	1,093
Total costs and other			1,303	1,243
Non-operating (loss) income			23	34
NET (LOSS) INCOME			271	(116)
NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCK			271
Reportable Legal Entity | Combined Non-Guarantor Subsidiaries
NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCK
Total revenues and other			10	2
Total costs and other			9	$ 2
NET (LOSS) INCOME			1
Net income attributable to noncontrolling interest			(1)
Eliminations
NET (LOSS) INCOME ATTRIBUTABLE TO COMMON STOCK
Total revenues and other			(32)
Total costs and other			$ (32)