Income Taxes Provision for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Current Federal Tax Expense (Benefit)	$ 2,774	$ 21,123	$ 18,601
Current State and Local Tax Expense (Benefit)	2,263	2,347	745
Current Foreign Tax Expense (Benefit)	3,170	1,118	1,426
Current Income Tax Expense (Benefit)	8,207	24,588	20,772
Deferred Federal Income Tax Expense (Benefit)	(20,878)	(2,045)	4,524
Deferred State and Local Income Tax Expense (Benefit)	(4,619)	(767)	(960)
Deferred Foreign Income Tax Expense (Benefit)	(71)	304	378
Deferred Income Tax Expense (Benefit)	(25,568)	(2,508)	3,942
PROVISION FOR INCOME TAXES	$ (17,361)	$ 22,080	$ 24,714