Acquisitions and Divestiture - Unaudited Pro Forma Operating Results (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
(Actual)
Net sales	$ 220,811		$ 186,413		$ 438,836	$ 378,073
Net (loss) income	$ (6,946)	$ 3,890	$ 10,450	$ 11,054	$ (3,056)	$ 21,504
Earnings per share:
Basic (USD per share)	$ (0.40)		$ 0.61		$ (0.18)	$ 1.25
Diluted (USD per share)	$ (0.40)		$ 0.60		$ (0.18)	$ 1.24
Basic (shares)	17,267		17,196		17,260	17,178
Diluted (shares)	17,267		17,335		17,260	17,334
Interface
(Actual)
Net sales	$ 220,811				$ 438,836
Net (loss) income	$ (6,946)				$ (3,056)
(Pro Forma)
Net sales			$ 226,404			$ 457,481
Net (loss) income			$ 11,589			$ 22,518
Earnings per share:
Basic (USD per share)			$ 0.67			$ 1.31
Diluted (USD per share)			$ 0.67			$ 1.30
Basic (shares)			17,196			17,178
Diluted (shares)			17,335			17,334