Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 318,974	$ 257,191
Trade receivables, net	212,099	263,213
Inventories, net	368,307	362,181
Deferred income taxes	24,810	23,838
Prepaids and other current assets	17,984	17,965
Total current assets	942,174	924,388
Property, plant and equipment, net	299,041	295,982
Other assets	10,725	11,077
Total assets	1,251,940	1,231,447
Current liabilities:
Accounts payable	38,476	28,302
Accrued income taxes	13,135	5,604
Customer prepayments	58,023	86,313
Accrued compensation	12,795	14,620
Other accrued liabilities	22,389	20,250
Total current liabilities	144,818	155,089
Deferred income taxes	9,829	9,926
Total liabilities	154,647	165,015
Commitments and contingencies (Note 7)
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, 40,548,436 and 40,475,061 shares issued and outstanding at March 31, 2013 and December 31, 2012	405	405
Additional paid-in capital	185,511	179,868
Retained earnings	939,830	899,989
Accumulated other comprehensive gains (losses)	(28,453)	(13,830)
Total stockholders' equity	1,097,293	1,066,432
Total liabilities and stockholders' equity	$ 1,251,940	$ 1,231,447