Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Current:
State	$ 1	$ 1	$ 1	$ 1
Foreign	0	0	0	0
Total	1	1	1	1
Deferred:
State	(6)	(7)	(4)	(6)
Foreign	(75)	6	(76)	8
Total	(81)	(1)	(80)	2
Provision (benefit) for income taxes	(80)	0	(79)	3
Asset Impairment Charges	396	24	402	27
TEXAS [Member]
Deferred:
State		(7)		(7)
Alberta Provincial Tax [Member]
Deferred:
Foreign		$ 8		$ 8
Canadian Operations [Member]
Deferred:
Asset Impairment Charges	$ 341		$ 341