Quarterly Results (Unaudited) (As Corrected) (Quarterly Results) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Nov. 30, 2020	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Net sales		$ 116,700	$ 134,772	$ 125,596	$ 137,483	$ 122,574	$ 113,500	$ 119,437	$ 113,822	$ 514,551	$ 469,333	$ 433,947
Gross profit		33,923	40,848	38,131	42,947	36,381	27,410	30,204	25,430	155,849	119,425	103,533
Net income		$ 18,892	$ 20,460	$ 17,804	$ 21,853	$ 17,273	$ 14,290	$ 13,391	$ 8,757	$ 79,009	$ 53,711	$ 42,329
Earnings per share:
Basic (usd per share)		$ 0.36	$ 0.39	$ 0.34	$ 0.42	$ 0.33	$ 0.27	$ 0.26	$ 0.17	$ 1.51	$ 1.03	$ 0.81
Diluted (usd per share)		$ 0.35	$ 0.38	$ 0.34	$ 0.41	$ 0.33	$ 0.26	$ 0.26	$ 0.17	$ 1.49	$ 1.02	$ 0.80
Insurance proceeds	$ 6,400	$ 4,100								$ 6,417	$ 0	$ 0
Earnings per share, basic and diluted (in dollars per share)		$ 0.08