Acquisitions and Divestiture - Unaudited Pro Forma Operating Results (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
(Actual)
Net sales	$ 205,274	$ 197,886	$ 644,110	$ 575,959
Net (loss) income	$ 3,004	$ 6,256	$ (52)	$ 27,760
Earnings per share:
Basic (USD per share)	$ 0.17	$ 0.36	$ 0.00	$ 1.61
Diluted (USD per share)	$ 0.17	$ 0.36	$ 0	$ 1.60
Basic (shares)	17,270	17,216	17,264	17,189
Diluted (shares)	17,330	17,349	17,264	17,339
Interface
(Actual)
Net sales	$ 205,274		$ 644,110
Net (loss) income	$ 3,004		$ (52)
(Pro Forma)
Net sales		$ 220,937		$ 678,418
Net income (loss)		$ 6,452		$ 29,303
Earnings per share:
Basic (USD per share)		$ 0.37		$ 1.70
Diluted (USD per share)		$ 0.37		$ 1.69
Basic (shares)		17,216		17,189
Diluted (shares)		17,349		17,339