CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data	Common Stock	Additional Paid-In Capital	Accumulated other Comprehensive Income (Loss)	Accumulated Deficit	Total
Beginning balance, amount at Mar. 31, 2011	$ 62	$ 208,218	$ (73)	$ (192,346)	$ 15,861
Beginning balance, shares at Mar. 31, 2011	62,379,030
Issuance of common stock under stock plans	2	3,050	0	0	3,052
Issuance of common stock under stock plans, shares	2,261,724
Issuance of common stock for acquisition of businesses, net of issuance costs	7	31,565	0	0	31,572
Issuance of common stock for acquisition of businesses, net of issuance costs, shares	6,692,569
Repurchase of common stock	0	(2,400)	0	0	(2,400)
Repurchase of common stock, shares	(653,830)
Buyback of employee stock options and stock purchase rights	0	(384)	0	0	(384)
Stock compensation charge	0	1,506	0	0	1,506
Income tax benefit from stock-based compensation					0
Unrealized investment gain (loss)	0	0	15	0	15
Foreign currency translation adjustment					0
Net income	0	0	0	69,228	69,228
Ending balance, amount at Mar. 31, 2012	71	241,555	(58)	(123,118)	118,450
Ending balance, shares at Mar. 31, 2012	70,679,493
Issuance of common stock under stock plans	1	2,400	0	0	2,401
Issuance of common stock under stock plans, shares	1,503,238
Cost of issuance of common stock	0	(43)	0	0	(43)
Repurchase of common stock	0	(419)	0	0	(419)
Repurchase of common stock, shares	(73,751)
Stock compensation charge	0	2,634	0	0	2,634
Income tax benefit from stock-based compensation	0	49	0	0	49
Unrealized investment gain (loss)	0	0	22	0	22
Foreign currency translation adjustment					0
Net income	0	0	0	13,939	13,939
Ending balance, amount at Mar. 31, 2013	72	246,176	(36)	(109,179)	137,033
Ending balance, shares at Mar. 31, 2013	72,108,980
Issuance of common stock under stock plans	2	5,165	0	0	5,167
Issuance of common stock under stock plans, shares	2,091,435
Issuance of common stock, net of issuance costs	14	125,736	0	0	125,750
Issuance of common stock, net of issuance costs, shares	14,375,000
Repurchase of common stock	0	(489)	0	0	(489)
Repurchase of common stock, shares	(50,400)
Stock compensation charge	0	7,595	0	0	7,595
Income tax benefit from stock-based compensation	0	142	0	0	142
Unrealized investment gain (loss)	0	0	(41)	0	(41)
Foreign currency translation adjustment	0	0	507	0	507
Net income	0	0	0	2,514	2,514
Ending balance, amount at Mar. 31, 2014	$ 88	$ 384,325	$ 430	$ (106,665)	$ 278,178
Ending balance, shares at Mar. 31, 2014	88,525,015