Divestitures (Details) - USD ($) $ in Millions			3 Months Ended			9 Months Ended		12 Months Ended
		Jun. 30, 2015	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues					$ 0		$ 619
Income from operations (1)	[1]				0		104
Loss on disposal					(5)		(77)
Net (loss) income before income taxes					(5)		27
Income tax benefit (expense)					2		(91)
Loss from discontinued operations, net of tax			$ 0		(3)	$ 0	(64)
ITO [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Additional pre-tax loss on disposal								$ 24
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax								$ 14
Payment for adjustment to sales price				$ 52
Payment/adjustment to sales price				$ 28
Payment due from closing		$ 24
Revenues					0		619
Income from operations (1)	[1]				0		104
Loss on disposal					(5)		(77)
Net (loss) income before income taxes					(5)		27
Income tax benefit (expense)					2		(91)
Loss from discontinued operations, net of tax					(3)		(64)
Disposal Group, Including Discontinued Operation, Depreciation and Amortization							80
Disposal Group, Including Discontinued Operations, Amortization							14
All Other Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues					0		0
Income from operations (1)					0		0
Loss on disposal					0		0
Net (loss) income before income taxes					0		0
Income tax benefit (expense)					0		0
Loss from discontinued operations, net of tax					$ 0		$ 0

[1] ITO Income from operations for the nine months ended September 30, 2015, excludes approximately $80 of depreciation and amortization expenses (including $14 of intangible amortization) since the business was held for sale.