Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 150,943	$ 116,255
Marketable debt securities - current	20,011	20,020
Accounts receivable, net of allowance for doubtful accounts of $460 and $397, respectively	12,454	13,844
Inventories	24,884	24,851
Prepaid expenses	5,079	5,778
Deferred income taxes	4,474	4,443
Other current assets	6,042	6,004
Total current assets	223,887	191,195
Marketable debt securities - non-current	10,029	10,042
Property and equipment, net	49,456	43,850
Deferred income taxes	15,551	12,964
Other assets	4,958	4,606
Total assets	303,881	262,657
Current liabilities:
Accounts payable	53,873	50,141
Customer prepayments	19,877	13,529
Compensation and benefits	17,379	29,806
Taxes and withholding	19,187	9,883
Other current liabilities	17,698	15,691
Total current liabilities	128,014	119,050
Non-current liabilities:
Warranty liabilities	2,752	2,714
Other long-term liabilities	11,670	11,502
Total non-current liabilities	142,436	133,266
Shareholders' equity:
Undesignated preferred stock; 5,000 shares authorized, no shares issued and outstanding	0	0
Common stock, $0.01 par value; 142,500 shares authorized, 56,705 and 56,397 shares issued and outstanding, respectively	567	564
Additional paid-in capital	57,347	47,701
Retained earnings	103,518	81,101
Accumulated other comprehensive income	13	25
Total shareholders' equity	161,445	129,391
Total liabilities and shareholders' equity	$ 303,881	$ 262,657