Income Taxes - Effective Tax Rates (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Income Taxes [Abstract]
Consolidated effective tax rate	37.70%	37.20%
Accumulated undistributed foreign earnings	$ 2,000
Cumulative unrecognized deferred tax liabilities	$ 250