Accumulated Other Comprehensive Income Accumulated Other Comprehensive Income by Component (Details) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning balance		$ 48	$ (2)
Other Comprehensive Income (Loss) before Reclassifications		(1)	(1)
Amounts reclassified from AOCI		0	0
Accumulated Other Comprehensive Income (Loss), Ending balance		47	(3)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning balance	[1]	50	0
Other Comprehensive Income (Loss) before Reclassifications	[1]	0	0
Amounts reclassified from AOCI	[1]	0	0
Accumulated Other Comprehensive Income (Loss), Ending balance	[1]	50	0
Equity Method Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning balance		(2)	(2)
Other Comprehensive Income (Loss) before Reclassifications		(1)	(1)
Amounts reclassified from AOCI		0	0
Accumulated Other Comprehensive Income (Loss), Ending balance		$ (3)	$ (3)

[1] Amounts are net of tax.