Income Taxes Provision for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Current Federal Tax Expense (Benefit)	$ 21,123	$ 18,601	$ 13,860
Current State and Local Tax Expense (Benefit)	2,347	745	(1,305)
Current Foreign Tax Expense (Benefit)	1,118	1,426	2,100
Current Income Tax Expense (Benefit)	24,588	20,772	14,655
Deferred Federal Income Tax Expense (Benefit)	(2,045)	4,524	(2,325)
Deferred State and Local Income Tax Expense (Benefit)	(767)	(960)	988
Deferred Foreign Income Tax Expense (Benefit)	304	378	139
Deferred Income Tax Expense (Benefit)	(2,508)	3,942	(1,198)
Income Tax Expense (Benefit)	$ 22,080	$ 24,714	$ 13,457