CONSOLIDATED BALANCE SHEETS (USD $) In Thousands	12 Months Ended
	Mar. 31, 2011	Mar. 31, 2010
Current assets:
Cash and cash equivalents	$ 284,375	$ 349,961
Short-term investments	145,581	19,231
Accounts receivable, net	103,289	88,328
Inventory, net	56,473	70,518
Deferred income taxes	11,349	10,911
Other current assets	16,653	21,782
Assets held for sale	0	8,861
Total current assets	617,720	569,592
Long-term investments	39,332	0
Property, plant and equipment, net	70,622	65,700
Intangibles, net	856	3,449
Goodwill	14,005	14,005
Other assets	2,112	2,605
Total assets	744,647	655,351
Current liabilities:
Accounts payable	33,995	23,779
Accrued liabilities	59,607	45,837
Total current liabilities	93,602	69,616
Deferred tax liability	3,526	551
Long-term income taxes payable	11,524	12,926
Other long-term liabilities	1,143	924
Total liabilities	109,795	84,017
Commitments and contingencies (Note 11)
Stockholders' equity:
Preferred stock, $0.01 par value per share; 1,000 shares authorized, no shares outstanding	0	0
Common stock, $0.01 par value per share; 100,000 shares authorized, 50,043 shares and 51,449 shares issued at 2011 and 2010, respectively	720	695
Additional paid-in capital	499,027	428,407
Accumulated other comprehensive income	1,473	6,272
Retained earnings	192,468	195,293
Total stockholders' equity before treasury stock	693,688	630,667
Less: Treasury stock (common: 1,728 and 2,579 shares at 2011 and 2010, respectively) at cost	(58,836)	(59,333)
Total stockholders' equity	634,852	571,334
Total liabilities and stockholders' equity	$ 744,647	$ 655,351