Acquisitions - Summary of Unaudited Consolidated Results of Operations, Including Proforma Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
As Reported
Net Sales	$ 190,897	$ 179,337	$ 186,549	$ 171,069	$ 157,715	$ 156,975	$ 151,071	$ 138,077	$ 727,852	$ 603,838	$ 542,149
Net income	$ 6,806	$ (3,569)	$ 9,483	$ 14,803	$ 7,507	$ 973	$ 7,290	$ 4,351	$ 27,523	$ 20,121	$ 23,802
Basic (in dollars per share)	$ 0.14	$ (0.07)	$ 0.19	$ 0.33	$ 0.17	$ 0.02	$ 0.16	$ 0.10	$ 0.56	$ 0.45	$ 0.54
Diluted (in dollars per share)	$ 0.13	$ (0.07)	$ 0.19	$ 0.32	$ 0.17	$ 0.02	$ 0.16	$ 0.10	$ 0.55	$ 0.45	$ 0.53
Pro Forma
Net Sales, Pro Forma									$ 730,612	$ 664,366	$ 575,541
Net Income, Pro Forma									$ 17,419	$ 23,068	$ 3,135
Basic, Pro Forma (in dollars per share)									$ 0.36	$ 0.52	$ 0.07
Diluted, Pro Forma (in dollars per share)									$ 0.35	$ 0.51	$ 0.07