Income Taxes - Effective Tax Rates (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Income Taxes [Abstract]
Consolidated effective tax rate	38.10%	37.80%
Accumulated undistributed foreign earnings	$ 2,800
Cumulative unrecognized deferred tax liabilities	$ 405