Revenue Recognition (Impact of New Revenue Guidance on Balance Sheet) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Assets
Accounts Receivable	$ 41,130		$ 79,120
Inventory	94,924		71,524
Liabilities
Deferred tax liability	41,018		39,269
Stockholders' Equity:
Retained Earnings	108,140		$ 115,737
Accounting Standards Update (“ASU”) No. 2014-09 | Balances without adoption of Topic 606
Assets
Accounts Receivable	39,039
Inventory	96,610
Liabilities
Deferred tax liability	40,913
Stockholders' Equity:
Retained Earnings	107,762
Accounting Standards Update (“ASU”) No. 2014-09 | Effect of Change Higher/(Lower)
Assets
Accounts Receivable	2,091
Inventory	(1,686)
Liabilities
Deferred tax liability	105
Stockholders' Equity:
Retained Earnings	$ 378	$ 378