Income Taxes - Effective Tax Rates (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Taxes [Abstract]
Consolidated effective tax rate	37.20%	37.80%
Accumulated undistributed foreign earnings	$ 2,400
Cumulative unrecognized deferred tax liabilities	$ 340