CONSOLIDATED QUARTERLY FINANCIAL DATA (UNAUDITED) - Summary of the Unaudited Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	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, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Data [Abstract]
Net sales	$ 579,001	$ 580,908	$ 626,053	$ 533,174	$ 610,196	$ 553,073	$ 612,690	$ 491,319	$ 543,444	$ 425,098	$ 435,903	$ 362,716	$ 2,319,136	$ 2,267,278	$ 1,767,161
Gross profit	72,307	77,735	87,650	68,690	69,056	65,162	85,315	64,119	72,876	60,963	67,679	59,357	306,382	283,651	260,875
Net income for the year	$ 18,375	$ 25,460	$ 30,960	$ 14,780	$ 11,584	$ 4,664	$ 31,902	$ 21,272	$ 49,357	$ 18,947	$ 22,945	$ 20,173	$ 89,575	$ 69,421	$ 111,422
Basic net income per share (in dollars per share)	$ 0.34	$ 0.47	$ 0.56	$ 0.27	$ 0.21	$ 0.08	$ 0.55	$ 0.37	$ 0.84	$ 0.32	$ 0.38	$ 0.34	$ 1.64	$ 1.22	$ 1.88
Diluted net income per share (in usd per share)	$ 0.34	$ 0.46	$ 0.56	$ 0.27	$ 0.21	$ 0.08	$ 0.54	$ 0.35	$ 0.80	$ 0.30	$ 0.36	$ 0.32	$ 1.62	$ 1.19	$ 1.78