CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Mar. 31, 2011
Current assets:
Cash and cash equivalents	$ 178,063	$ 277,373
Short-term investments	119,459	152,583
Accounts receivable, net	109,677	103,289
Inventory, net	57,799	56,473
Deferred tax asset	11,805	11,349
Other current assets	16,941	16,653
Total current assets	493,744	617,720
Long-term investments	61,961	39,332
Property, plant and equipment, net	75,537	70,622
Goodwill and purchased intangibles, net	14,461	14,861
Other assets	2,137	2,112
Total assets	647,840	744,647
Current liabilities:
Accounts payable	21,650	33,995
Accrued liabilities	50,794	59,607
Total current liabilities	72,444	93,602
Deferred tax liability	6,136	3,526
Long-term income taxes payable	12,453	11,524
Revolving line of credit	39,500	0
Other long-term liabilities	1,039	1,143
Total liabilities	131,572	109,795
Commitments and contingencies (Note 10)
Stockholders' equity:
Common stock	736	720
Additional paid-in capital	526,022	499,027
Accumulated other comprehensive income	6,531	1,473
Retained earnings	93,628	192,468
Total stockholders' equity before treasury stock	626,917	693,688
Less: Treasury stock, at cost	(110,649)	(58,836)
Total stockholders' equity	516,268	634,852
Total liabilities and stockholders' equity	$ 647,840	$ 744,647