Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 66,700	$ 72,100
Accumulated amortization of amortized intangible assets	11,300	5,600
Write-off of intangibles	4,149
Amortization of intangible assets	6,864	5,330
Cost of Goods Sold [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	3,300	2,600
Selling, General and Administrative Expenses [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 3,600	$ 2,700