Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Mar. 31, 2013
Current assets:
Cash and cash equivalents	$ 94,917	$ 99,930
Marketable securities	42,094	37,338
Accounts receivable, net of allowance for doubtful accounts of $147 and $971 at September 30, 2013 and March 31, 2013, respectively	55,672	73,900
Inventories	10,728	7,563
Prepaid income taxes	1,920	0
Deferred income taxes	9,434	9,538
Prepaid expenses and other current assets	8,292	9,043
Total current assets	223,057	237,312
Fixed assets, net	21,797	19,678
Goodwill	202,863	202,453
Intangible assets, net	60,896	63,827
Deferred income taxes	8,065	9,211
Long-term marketable securities	22,438	16,823
Other assets	2,285	2,872
Total assets	541,401	552,176
Current liabilities:
Accounts payable	8,719	10,161
Accrued compensation	23,766	31,585
Accrued other	7,292	8,256
Income taxes payable	0	114
Deferred revenue	88,319	95,055
Total current liabilities	128,096	145,171
Other long-term liabilities	2,531	2,249
Deferred tax liability	979	941
Accrued long-term retirement benefits	1,575	1,757
Long-term deferred revenue	21,294	25,907
Contingent liabilities, net of current portion	4,139	4,248
Total liabilities	158,614	180,273
Commitments and contingencies
Preferred stock, $0.001 par value:
5,000,000 shares authorized; no shares issued or outstanding at September 30, 2013 and March 31, 2013	0	0
Common stock, $0.001 par value:
150,000,000 shares authorized; 49,706,643 and 49,007,491 shares issued and 41,504,713 and 41,466,921 shares outstanding at September 30, 2013 and March 31, 2013, respectively	50	49
Additional paid-in capital	263,887	253,202
Accumulated other comprehensive income	2,082	671
Treasury stock at cost, 8,201,930 and 7,540,570 shares at September 30, 2013 and March 31, 2013, respectively	(99,829)	(83,480)
Retained earnings	216,597	201,461
Total stockholders’ equity	382,787	371,903
Total liabilities and stockholders’ equity	$ 541,401	$ 552,176