Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Total
Balance at Mar. 31, 2016	$ 3,205	$ 135,424	$ (95,167)	$ 43,462
Balance (in shares) at Mar. 31, 2016	32,048
Increase (Decrease) in Stockholders' Equity
Stock option exercises	$ 40	628		668
Stock option exercises (in shares)	388
Stock-based compensation		976		976
Issuance of shares pursuant to vesting of restricted stock units, net of payroll withholding taxes	$ 4	(60)		(56)
Issuance of shares pursuant to vesting of restricted stock units, net of payroll withholding taxes (in shares)	52
Net income (loss)			(4,826)	(4,826)
Balance at Mar. 31, 2017	$ 3,249	136,968	(99,993)	40,224
Balance (in shares) at Mar. 31, 2017	32,488
Increase (Decrease) in Stockholders' Equity
Stock option exercises	$ 59	1,131		1,190
Stock option exercises (in shares)	591
Stock-based compensation		1,781		1,781
Issuance of shares pursuant to vesting of restricted stock units, net of payroll withholding taxes	$ 10	(158)		(148)
Issuance of shares pursuant to vesting of restricted stock units, net of payroll withholding taxes (in shares)	107
Net income (loss)			(3,526)	(3,526)
Balance at Mar. 31, 2018	$ 3,318	139,722	(103,519)	$ 39,521
Balance (in shares) at Mar. 31, 2018	33,186			33,186
Increase (Decrease) in Stockholders' Equity
Stock option exercises	$ 4	81		$ 85
Stock option exercises (in shares)	43
Issuance of shares pursuant to Employee Stock Purchase Plan	$ 10	355		365
Issuance of shares pursuant to Employee Stock Purchase Plan (in Shares)	92
Stock-based compensation		2,156		2,156
Adoption of ASU 2014-09 (see Note 1)			(208)	(208)
Issuance of shares pursuant to vesting of restricted stock units, net of payroll withholding taxes	$ 6	(54)		(48)
Issuance of shares pursuant to vesting of restricted stock units, net of payroll withholding taxes (in shares)	56
Net income (loss)			(7,816)	(7,816)
Balance at Mar. 31, 2019	$ 3,338	$ 142,260	$ (111,543)	$ 34,055
Balance (in shares) at Mar. 31, 2019	33,377			33,377