Segment Reporting and Foreign Operations - Narrative (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) segment	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment									2
Segment Reporting Information [Line Items]
Net Sales	$ 233,249	$ 221,659	$ 224,810	$ 203,035	$ 190,897	$ 179,337	$ 186,549	$ 171,069	$ 882,753	$ 727,852	$ 603,838
Foreign sales as a percent of total sales	44.00%				42.00%				44.00%	42.00%	39.00%
International
Segment Reporting Information [Line Items]
Net Sales									$ 386,340	$ 307,149	$ 233,488
Foreign sales									$ 92,700	$ 73,400	$ 59,900