Quarterly Financial Data - Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 27, 2015	Jun. 28, 2015	Mar. 29, 2015	Dec. 31, 2014	Sep. 28, 2014	Jun. 29, 2014	Mar. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Selected Quarterly Financial Information
Net sales	$ 93,282	$ 90,646	$ 100,071	$ 98,311	$ 100,378	$ 99,957	$ 102,980	$ 100,706	$ 382,310	$ 404,021	$ 409,461
Gross margin	30,154	31,446	33,373	32,136	33,026	32,499	33,823	30,615	127,109	129,963	121,353
Operating earnings (loss)	931	(3,850)	10,544	10,488	10,310	11,223	9,945	10,845	18,113	42,323	17,687
Net earnings (loss)	$ (13,653)	$ (4,760)	$ 19,080	$ 6,287	$ 6,964	$ 8,117	$ 6,361	$ 5,080	$ 6,954	$ 26,522	$ (3,929)
Basic earnings per share (usd per share)	$ (0.42)	$ (0.15)	$ 0.58	$ 0.19	$ 0.21	$ 0.24	$ 0.19	$ 0.15	$ 0.21	$ 0.79	$ (0.12)
Diluted earnings per share (usd per share)	$ (0.42)	$ (0.15)	$ 0.57	$ 0.19	$ 0.21	$ 0.24	$ 0.19	$ 0.15	$ 0.21	$ 0.78	$ (0.12)