Income Taxes Income Tax (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Valuation Allowance [Line Items]
Provision for income taxes	$ 8,196	$ 9,034	$ 17,648	$ 14,560
Effective Income Tax Rate Reconciliation, Percent	32.50%	36.20%	34.30%	36.70%