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, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
As Reported
Net Sales	$ 233,249	$ 221,659	$ 224,810	$ 203,035	$ 190,897	$ 179,337	$ 186,549	$ 171,069	$ 882,753	$ 727,852	$ 603,838
Net income	$ 9,188	$ 16,619	$ 10,941	$ 5,269	$ 6,806	$ (3,569)	$ 9,483	$ 14,803	$ 42,017	$ 27,523	$ 20,121
Basic (in dollars per share)	$ 0.17	$ 0.31	$ 0.22	$ 0.10	$ 0.14	$ (0.07)	$ 0.19	$ 0.33	$ 0.80	$ 0.56	$ 0.45
Diluted (in dollars per share)	$ 0.16	$ 0.30	$ 0.21	$ 0.10	$ 0.13	$ (0.07)	$ 0.19	$ 0.32	$ 0.78	$ 0.55	$ 0.45
Pro Forma
Net Sales, Pro Forma									$ 928,336	$ 768,571	$ 664,366
Net Income, Pro Forma									$ 20,699	$ (13,720)	$ 23,054
Basic, Pro Forma (in dollars per share)									$ 0.40	$ (0.28)	$ 0.52
Diluted, Pro Forma (in dollars per share)									$ 0.38	$ (0.27)	$ 0.51