Guarantor Finanical Information Balance Sheet (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Cash and cash equivalents	$ 21,370	$ 21,607	$ 16,554	$ 30,524
Accounts receivable, less allowance for doubtful accounts	163,469	138,311
Receivables from affiliates	0	0
Inventories	270,256	303,772
Prepaid expenses and other current assets	23,819	22,688
Total current assets	478,914	486,378
Investment in joint venture	37,632	38,854
Goodwill	70,007	70,300
Intangible assets	79,102	82,477
Other assets	31,988	31,157
Investment in subsidiaries	0	0
Receivables from affiliates	0	0
Property, plant and equipment, net	77,149	79,640
Total assets	774,792	788,806
Accounts payable	88,572	67,990
Payables due to affiliates	0	0
Other current liabilities	43,745	38,127
Current portion of long-term debt and short-term debt	899	915
Total current liabilities	133,216	107,032
Long-term debt, less current portion	265,761	296,154
Payables due to affiliates	0	0
Deferred income taxes	31,799	32,350
Other non-current liabilities	16,508	15,930
Stockholders’ equity	327,508	337,340
Total liabilities and stockholders’ equity	774,792	788,806
Parent
Cash and cash equivalents	3,659	3,332	1,300	11,534
Accounts receivable, less allowance for doubtful accounts	73,333	60,293
Receivables from affiliates	341	95
Inventories	151,687	183,189
Prepaid expenses and other current assets	17,630	16,141
Total current assets	246,650	263,050
Investment in joint venture	37,632	38,854
Goodwill	12,921	12,921
Intangible assets	33,369	34,343
Other assets	28,240	28,142
Investment in subsidiaries	241,360	245,798
Receivables from affiliates	66,644	62,696
Property, plant and equipment, net	50,096	52,424
Total assets	716,912	738,228
Accounts payable	55,658	40,510
Payables due to affiliates	906	742
Other current liabilities	32,274	26,566
Current portion of long-term debt and short-term debt	371	386
Total current liabilities	89,209	68,204
Long-term debt, less current portion	262,451	292,086
Payables due to affiliates	9,705	12,114
Deferred income taxes	13,720	14,209
Other non-current liabilities	14,319	14,275
Stockholders’ equity	327,508	337,340
Total liabilities and stockholders’ equity	716,912	738,228
Guarantors
Cash and cash equivalents	1,805	1,677	2,277	582
Accounts receivable, less allowance for doubtful accounts	38,102	34,037
Receivables from affiliates	1,625	1,118
Inventories	45,927	44,874
Prepaid expenses and other current assets	(1,270)	(1,490)
Total current assets	86,189	80,216
Investment in joint venture	0	0
Goodwill	41,556	41,556
Intangible assets	26,808	28,325
Other assets	201	(98)
Investment in subsidiaries	10,062	11,526
Receivables from affiliates	85,846	83,891
Property, plant and equipment, net	15,673	15,403
Total assets	266,335	260,819
Accounts payable	16,847	13,434
Payables due to affiliates	88	95
Other current liabilities	3,431	3,478
Current portion of long-term debt and short-term debt	0	1
Total current liabilities	20,366	17,008
Long-term debt, less current portion	0	0
Payables due to affiliates	15,677	11,994
Deferred income taxes	18,614	18,614
Other non-current liabilities	1,877	1,339
Stockholders’ equity	209,801	211,864
Total liabilities and stockholders’ equity	266,335	260,819
Non-Guarantors
Cash and cash equivalents	15,906	16,598	12,977	18,408
Accounts receivable, less allowance for doubtful accounts	52,034	43,981
Receivables from affiliates	0	668
Inventories	72,710	75,777
Prepaid expenses and other current assets	7,661	8,239
Total current assets	148,311	145,263
Investment in joint venture	0	0
Goodwill	15,530	15,823
Intangible assets	18,925	19,809
Other assets	3,547	3,113
Investment in subsidiaries	0	0
Receivables from affiliates	4,261	3,280
Property, plant and equipment, net	11,380	11,813
Total assets	201,954	199,101
Accounts payable	16,067	14,046
Payables due to affiliates	972	1,044
Other current liabilities	8,040	8,083
Current portion of long-term debt and short-term debt	528	528
Total current liabilities	25,607	23,701
Long-term debt, less current portion	3,310	4,068
Payables due to affiliates	131,369	125,759
Deferred income taxes	(535)	(473)
Other non-current liabilities	312	316
Stockholders’ equity	41,891	45,730
Total liabilities and stockholders’ equity	201,954	199,101
Eliminations
Cash and cash equivalents	0	0	0	0
Accounts receivable, less allowance for doubtful accounts	0	0
Receivables from affiliates	(1,966)	(1,881)
Inventories	(68)	(68)
Prepaid expenses and other current assets	(202)	(202)
Total current assets	(2,236)	(2,151)
Investment in joint venture	0	0
Goodwill	0	0
Intangible assets	0	0
Other assets	0	0
Investment in subsidiaries	(251,422)	(257,324)
Receivables from affiliates	(156,751)	(149,867)
Property, plant and equipment, net	0	0
Total assets	(410,409)	(409,342)
Accounts payable	0	0
Payables due to affiliates	(1,966)	(1,881)
Other current liabilities	0	0
Current portion of long-term debt and short-term debt	0	0
Total current liabilities	(1,966)	(1,881)
Long-term debt, less current portion	0	0
Payables due to affiliates	(156,751)	(149,867)
Deferred income taxes	0	0
Other non-current liabilities	0	0
Stockholders’ equity	(251,692)	(257,594)
Total liabilities and stockholders’ equity	$ (410,409)	$ (409,342)