Acquisitions - Unaudited Pro Forma Operating Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Business Combinations [Abstract]
Net sales	$ 180,041	$ 155,725	$ 520,407	$ 422,660
Net income	$ 10,675	12,785	$ 35,469	32,767
(Unaudited Pro Forma)
Net sales		169,126		499,875
Net income		$ 14,206		$ 37,532
Earnings per share:
Basic (in USD per share)	$ 0.63	$ 0.76	$ 2.08	$ 1.94
Diluted (in USD per share)	$ 0.62	0.75	$ 2.05	1.92
Earnings per share:
Basic (in dollars per share)		0.84		2.23
Diluted (in dollars per share)		$ 0.83		$ 2.20