Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 257,191	$ 298,576
Trade receivables, net	263,213	180,095
Inventories, net	362,181	277,802
Deferred income taxes	23,838	23,868
Prepaids and other current assets	17,965	18,961
Total current assets	924,388	799,302
Property, plant and equipment, net	295,982	274,599
Other assets	11,077	11,957
Total assets	1,231,447	1,085,858
Current liabilities:
Accounts payable	28,302	35,580
Current maturities of long-term debt		57
Accrued income taxes	5,604	5,447
Customer prepayments	86,313	76,610
Accrued compensation	14,620	12,584
Other accrued liabilities	20,250	20,722
Total current liabilities	155,089	151,000
Deferred income taxes	9,926	9,614
Total liabilities	165,015	160,614
Commitments and contingencies (Note 10)
Stockholders' equity:
Preferred stock: 10,000,000 shares authorized at $0.01 par value (none issued)
Common stock: 50,000,000 shares authorized at $0.01 par value, 40,475,061 and 40,175,426 issued and outstanding at December 31, 2012 and 2011	405	402
Additional paid-in capital	179,868	162,505
Retained earnings	899,989	780,780
Accumulated other comprehensive gains (losses)	(13,830)	(18,443)
Total stockholders' equity	1,066,432	925,244
Total liabilities and stockholders' equity	$ 1,231,447	$ 1,085,858