Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Net sales	$ 510,580	$ 543,275	$ 1,599,842	$ 1,622,117
Cost of goods sold	425,446	461,818	1,340,695	1,377,017
Gross profit	85,134	81,457	259,147	245,100
Selling, general and administrative expenses	74,580	79,951	229,156	233,479
Operating profit	10,554	1,506	29,991	11,621
Interest expense, net	2,273	1,950	7,050	5,589
Equity income from unconsolidated affiliate	73	151	377	424
Income (loss) before income taxes	8,354	(293)	23,318	6,456
Income tax expense	2,383	474	6,653	685
Net income (loss)	$ 5,971	$ (767)	$ 16,665	$ 5,771
Basic and Diluted Earnings (Loss) Per Common Share
Basic	$ 0.50	$ (0.06)	$ 1.40	$ 0.46
Diluted	$ 0.47	$ (0.06)	$ 1.35	$ 0.43
Weighted average number of common shares outstanding:
Basic	12,050	12,248	11,936	12,418
Diluted	12,795	12,248	12,343	13,325