Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Mar. 31, 2012
Current assets:
Cash and cash equivalents	$ 135,025	$ 117,255
Marketable securities	74,517	79,617
Accounts receivable, net of allowance for doubtful accounts of $565 and $226 at June 30, 2012 and March 31, 2012, respectively	38,809	69,795
Inventories	7,494	8,021
Prepaid income taxes	4,939	4,600
Deferred income taxes	4,336	4,237
Prepaid expenses and other current assets	5,588	6,162
Total current assets	270,708	289,687
Fixed assets, net	17,029	16,457
Goodwill	169,522	170,384
Intangible assets, net	52,452	54,685
Deferred income taxes	15,385	17,892
Long-term marketable securities	29,690	16,644
Other assets	1,840	2,008
Total assets	556,626	567,757
Current liabilities:
Accounts payable	8,106	7,539
Accrued compensation	19,119	23,050
Accrued other	5,799	6,235
Current portion of contingent liabilities	3,775	3,774
Deferred revenue	88,759	93,493
Total current liabilities	125,558	134,091
Other long-term liabilities	2,161	2,347
Deferred tax liability	1,330	1,410
Accrued long-term retirement benefits	1,933	1,990
Long-term deferred revenue	18,005	18,722
Long-term debt, net of current portion	62,000	62,000
Contingent liabilities, net of current portion	3,657	4,828
Total liabilities	214,644	225,388
Commitments and contingencies (Note 12)
Stockholders' equity:
Preferred stock, $0.001 par value: 5,000,000 shares authorized; no shares issued or outstanding at June 30, 2012 and March 31, 2012	0	0
Common stock, $0.001 par value: 150,000,000 shares authorized; 48,401,084 and 48,185,731 shares issued and 41,709,141 and 41,814,191 shares outstanding at June 30, 2012 and March 31, 2012, respectively	48	48
Additional paid-in capital	239,455	237,289
Accumulated other comprehensive income (loss)	(936)	212
Treasury stock at cost, 6,691,943 and 6,371,540 shares at June 30, 2012 and March 31, 2012, respectively	(62,445)	(56,032)
Retained earnings	165,860	160,852
Total stockholders' equity	341,982	342,369
Total liabilities and stockholders' equity	$ 556,626	$ 567,757