Annual report pursuant to Section 13 and 15(d)

Selected Quarterly Financial Information - Summarizes Selected Quarterly Financial Information (Detail)

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Selected Quarterly Financial Information - Summarizes Selected Quarterly Financial Information (Detail) - USD ($)
3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jul. 01, 2017
Apr. 01, 2017
Dec. 31, 2016
Oct. 01, 2016
Jul. 02, 2016
Apr. 02, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]                      
Sales $ 171,318,000 $ 149,636,000 $ 151,114,000 $ 152,396,000 $ 154,068,000 $ 155,099,000 $ 164,426,000 $ 159,530,000 $ 624,464,000 $ 633,123,000 $ 692,279,000
Gross Profit (sales less cost of products sold) 32,153,000 32,493,000 34,150,000 38,317,000 36,486,000 38,663,000 44,835,000 39,483,000 137,113,000 159,467,000 187,942,000
Impairment Loss 16,237,000 0 0 0 0 0 0 0 16,237,000 0 0
(Loss) Income Before Income Taxes (9,715,000) 8,646,000 10,569,000 15,491,000 14,296,000 16,422,000 21,555,000 16,512,000      
Net (Loss) Income $ (5,653,000) $ 6,060,000 $ 7,685,000 $ 11,587,000 $ 9,885,000 $ 12,074,000 $ 14,980,000 $ 11,485,000 $ 19,679,000 $ 48,424,000 $ 66,974,000
Basic earnings (loss) per share (in usd per share) $ (0.20) $ 0.21 $ 0.27 $ 0.40 $ 0.34 $ 0.42 $ 0.51 $ 0.39 $ 0.69 $ 1.66 $ 2.29
Diluted earnings (loss) per share (in usd per share) $ (0.20) $ 0.21 $ 0.26 $ 0.38 $ 0.33 $ 0.41 $ 0.50 $ 0.38 $ 0.67 $ 1.61 $ 2.22