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, 2014	$ 88	$ 384,325	$ 430	$ (106,665)	$ 278,178
Beginning 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
Issuance of common stock under stock plans	$ 3	4,564	0	0	4,567
Issuance of common stock under stock plans, shares	2,576,785
Cost of issuance of common stock	$ 0	(6)	0	0	(6)
Repurchase of common stock	$ (1)	(3,004)	0	0	(3,005)
Repurchase of common stock, shares	(289,899)
Stock-based compensation expense	$ 0	21,462	0	0	21,462
Income tax benefit from stock-based compensation	0	486	0	0	486
Unrealized investment gain (loss)	0	0	70	0	70
Foreign currency translation adjustment	0	0	(5,528)	0	(5,528)
Net income (loss)	0	0	0	(4,751)	(4,751)
Ending balance, amount at Mar. 31, 2017	$ 91	$ 412,762	$ (9,642)	$ (114,610)	$ 288,601
Ending balance, shares at Mar. 31, 2017	91,500,091