CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 420,938	$ 384,356
Trade receivables, net	266,086	279,253
Inventories, net	397,356	368,354
Deferred income taxes	25,702	24,951
Prepaids and other current assets	28,322	21,899
Total current assets	1,138,404	1,078,813
Property, plant and equipment, net	311,473	304,806
Other assets	10,172	10,993
Total assets	1,460,049	1,394,612
Current liabilities:
Accounts payable	53,597	38,801
Accrued income taxes	15,185	13,628
Customer prepayments	52,870	45,025
Accrued compensation	17,288	21,556
Other accrued liabilities	17,748	23,780
Total current liabilities	156,688	142,790
Deferred income taxes	9,656	9,804
Total liabilities	166,344	152,594
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, 40,829,349 and 40,822,627 shares issued and outstanding at March 31, 2014 and December 31, 2013	407	407
Additional paid-in capital	195,305	191,965
Retained earnings	1,112,434	1,069,816
Accumulated other comprehensive losses	(14,441)	(20,170)
Total stockholders' equity	1,293,705	1,242,018
Total liabilities and stockholders' equity	$ 1,460,049	$ 1,394,612