CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated other Comprehensive Income (Loss)	Accumulated Deficit	Total
Beginning balance, amount at Mar. 31, 2013	$ 72	$ 246,176	$ (36)	$ (109,179)	$ 137,033
Beginning 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-based compensation expense	$ 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 (loss)	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
Issuance of common stock under stock plans	$ 2	4,525	0	0	4,527
Issuance of common stock under stock plans, shares	2,043,781
Cost of issuance of common stock	$ 0	(8)	0	0	(8)
Repurchase of common stock	$ (2)	(19,369)	0	0	(19,371)
Repurchase of common stock, shares	(2,503,268)
Stock-based compensation expense	$ 0	9,347	0	0	9,347
Income tax benefit from stock-based compensation	0	151	0	0	151
Unrealized investment gain (loss)	0	0	(26)	0	(26)
Foreign currency translation adjustment	0	0	(2,513)	0	(2,513)
Net income (loss)	0	0	0	1,926	1,926
Ending balance, amount at Mar. 31, 2015	$ 88	378,971	(2,109)	(104,739)	272,211
Ending balance, shares at Mar. 31, 2015	88,065,528
Issuance of common stock under stock plans	$ 2	5,386	0	0	5,388
Issuance of common stock under stock plans, shares	2,218,470
Cost of issuance of common stock	$ 0	(3)	0	0	(3)
Issuance of common stock for acquisition of businesses, net of issuance costs	$ 0	0	0	0	0
Issuance of common stock for acquisition of businesses, net of issuance costs, shares	352,044
Repurchase of common stock	$ (1)	(11,652)	0	0	(11,653)
Repurchase of common stock, shares	(1,422,837)
Stock-based compensation expense	$ 0	16,334	0	0	16,334
Income tax benefit from stock-based compensation	0	224	0	0	224
Unrealized investment gain (loss)	0	0	(50)	0	(50)
Foreign currency translation adjustment	0	0	(2,025)	0	(2,025)
Net income (loss)	0	0	0	(5,120)	(5,120)
Ending balance, amount at Mar. 31, 2016	$ 89	$ 389,260	$ (4,184)	$ (109,859)	$ 275,306
Ending balance, shares at Mar. 31, 2016	89,213,205