Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Current assets
Cash and cash equivalents	$ 165,275	$ 175,553	$ 162,719
Trade accounts receivable, net	126,888	82,812	120,119
Inventories	196,247	204,124	185,217
Deferred income taxes	12,874	11,473	12,124
Assets held for sale	586	593
Other current assets	8,465	23,499	14,516
Total current assets	510,335	498,054	494,695
Property, plant and equipment, net	209,544	213,452	208,685
Goodwill	122,678	121,981	127,983
Intangible assets, net	43,346	50,598	41,529
Other noncurrent assets	11,082	6,237	6,013
Total assets	896,985	890,322	878,905
Current liabilities
Line of credit and notes payable	1,201	178	4,837
Trade accounts payable	29,579	37,117	34,740
Accrued liabilities	44,619	44,923	41,491
Income taxes payable			1,396
Accrued profit sharing trust contributions	3,229	5,191	2,393
Accrued cash profit sharing and commissions	12,010	3,414	10,307
Accrued workers' compensation	5,095	4,692	4,861
Total current liabilities	95,733	95,515	100,025
Long-term liabilities	8,221	5,239	5,936
Total liabilities	103,954	100,754	105,961
Commitments and contingencies (Note 7)
Stockholders' equity
Common stock, at par value	485	483	482
Additional paid-in capital	187,549	184,677	176,809
Retained earnings	609,538	592,309	591,595
Treasury stock	(9,825)
Accumulated other comprehensive income	5,284	12,099	4,058
Total stockholders' equity	793,031	789,568	772,944
Total liabilities and stockholders' equity	$ 896,985	$ 890,322	$ 878,905