Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Effective income tax rates	37.50%	37.10%	36.20%	36.20%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate			35.00%
Increase (Decrease) in Effective Tax Rate	0.40%		0.00%
Changes to Liability for Uncertain Tax Positions			$ 0.0