Significant Accounting Policies (ASU 2017-07 Retirement) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of sales	$ 646,202	$ 631,115
Selling, general and administrative expenses	127,851	126,205
Other income (expense)	$ (2,764)	(5,306)
Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of sales		634,185
Selling, general and administrative expenses		124,926
Other income (expense)		(3,515)
Accounting Standards Update 2017-07 | Reclassification
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of sales		(3,070)
Selling, general and administrative expenses		1,279
Other income (expense)		$ (1,791)