Revenue Recognition (Impact of New Revenue Guidance on Balance Sheet) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Assets
Accounts Receivable	$ 128,164		$ 79,120
Inventory	89,444		71,524
Liabilities
Deferred tax liability	46,447		39,269
Stockholders' Equity:
Retained Earnings	127,032		$ 115,737
Accounting Standards Update (“ASU”) No. 2014-09 | Balances without adoption of Topic 606
Assets
Accounts Receivable	126,052
Inventory	91,148
Liabilities
Deferred tax liability	46,341
Stockholders' Equity:
Retained Earnings	126,654
Accounting Standards Update (“ASU”) No. 2014-09 | Effect of Change Higher/(Lower)
Assets
Accounts Receivable	2,112
Inventory	(1,704)
Liabilities
Deferred tax liability	106
Stockholders' Equity:
Retained Earnings	$ 378	$ 378