Quarterly Financial Data - Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 27, 2015	Jun. 28, 2015	Mar. 29, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Selected Quarterly Financial Information
Net sales	$ 101,584	$ 99,697	$ 98,693	$ 96,705	$ 93,282	$ 90,646	$ 100,071	$ 98,311	$ 396,679	$ 382,310	$ 404,021
Gross margin	35,861	36,641	34,457	33,468	30,154	31,446	33,373	32,136	140,428	127,109	129,963
Operating earnings	14,146	12,490	24,097	12,433	931	(3,850)	10,544	10,488	63,166	18,113	42,323
Net (loss) earnings	$ 8,310	$ 3,720	$ 14,487	$ 7,863	$ (13,653)	$ (4,760)	$ 19,080	$ 6,287	$ 34,380	$ 6,954	$ 26,522
Basic earnings per share (usd per share)	$ 0.25	$ 0.11	$ 0.44	$ 0.24	$ (0.42)	$ (0.15)	$ 0.58	$ 0.19	$ 1.05	$ 0.21	$ 0.79
Diluted earnings per share (usd per share)	$ 0.25	$ 0.11	$ 0.44	$ 0.24	$ (0.42)	$ (0.15)	$ 0.57	$ 0.19	$ 1.03	$ 0.21	$ 0.78