Provision (Benefit) for Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

The Provision (benefit) for income taxes includes:

	Years Ended December 31,
	2015			2014		2013
	(Millions)
Current:
State	$	(3	)	$	3	$	2
Foreign	—			1		(22		)
	(3		)	4		(20		)
Deferred:
State	(3		)	8		15
Foreign	7			17		35
	4			25		50
Provision (benefit) for income taxes	$	1		$	29	$	30

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

Reconciliations from the Provision (benefit) at statutory rate to recorded Provision (benefit) for income taxes are as follows:

	Years Ended December 31,
	2015			2014			2013
	(Millions)
Provision (benefit) at statutory rate	$	(475	)	$	459		$	402
Increases (decreases) in taxes resulting from:
Income not subject to U.S. federal tax	475			(459		)	(402		)
State income taxes	(6		)	11			17
Foreign operations — net	7			18			13
Provision (benefit) for income taxes	$	1		$	29		$	30