Quarterly Results (Unaudited) (As Corrected) (Quarterly Results) (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, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 122,574	$ 113,500	$ 119,437	$ 113,822	$ 112,340	$ 112,937	$ 109,588	$ 99,082	$ 469,333	$ 433,947	$ 405,232
Gross profit	36,381	27,410	30,204	25,430	27,846	32,830	27,661	15,196	119,425	103,533	123,651
Net income	$ 17,273	$ 14,290	$ 13,391	$ 8,757	$ 12,964	$ 14,514	$ 11,697	$ 3,154	$ 53,711	$ 42,329	$ 53,830
Earnings per share:
Basic (usd per share)	$ 0.33	$ 0.27	$ 0.26	$ 0.17	$ 0.25	$ 0.28	$ 0.22	$ 0.06	$ 1.03	$ 0.81	$ 1.02
Diluted (usd per share)	$ 0.33	$ 0.26	$ 0.26	$ 0.17	$ 0.25	$ 0.27	$ 0.22	$ 0.06	$ 1.02	$ 0.80	$ 1.01