Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock, Shares	Common Stock, Additional Paid-in Capital	Treasury Stock	Shareholder Notes Receivable	Retained Earnings (Deficit)
Shareholders' equity, at beginning of period (shares) at Mar. 31, 2014		21,588,326
Shareholders' equity, beginning of period at Mar. 31, 2014	$ 77,012		$ 130,987	$ (36,034)	$ (50)	$ (17,891)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock for cash, net of issuance costs (shares)		5,462,500
Issuance of common stock for cash, net of issuance costs	17,465		17,465
Issuance of stock and warrants for services (shares)		27,931
Issuance of stock for services	131		131
Exercise of stock options for cash (shares)		178,387
Exercise of stock options and warrants for cash	430		430
Shares issued under Employee Stock Purchase Plan (shares)		1,486
Shares issued under Employee Stock Purchase Plan	11		4	7
Collection of shareholder notes receivable	46				46
Stock-based compensation (shares)		170,055
Stock-based compensation	1,499		1,499
Employee tax withholdings on stock-based compensation (shares)		(7,152)
Employee tax withholdings on stock-based compensation	(22)			(22)
Net loss	(32,061)					(32,061)
Shareholders' equity, at end of period (shares) at Mar. 31, 2015		27,421,533
Shareholders' equity, end of period at Mar. 31, 2015	64,511		150,516	(36,049)	(4)	(49,952)
Increase (Decrease) in Stockholders' Equity
Issuance of stock and warrants for services (shares)		35,290
Issuance of stock for services	66		66
Exercise of stock options for cash (shares)		46,410
Exercise of stock options and warrants for cash	$ 97		97
Shares issued under Employee Stock Purchase Plan (shares)	3,925	3,925
Shares issued under Employee Stock Purchase Plan	$ 7		(1)	8
Stock-based compensation (shares)		270,303
Stock-based compensation	1,462		1,462
Employee tax withholdings on stock-based compensation (shares)		(10,323)
Employee tax withholdings on stock-based compensation	(34)			(34)
Net loss	$ (20,126)					(20,126)
Shareholders' equity, at end of period (shares) at Mar. 31, 2016	27,767,138	27,767,138
Shareholders' equity, end of period at Mar. 31, 2016	$ 45,983		152,140	(36,075)	(4)	(70,078)
Increase (Decrease) in Stockholders' Equity
Issuance of stock and warrants for services (shares)		110,566
Issuance of stock for services	$ 156		156
Shares issued under Employee Stock Purchase Plan (shares)	5,156	5,156
Shares issued under Employee Stock Purchase Plan	$ 8		0	8
Stock-based compensation (shares)		444,102
Stock-based compensation	1,605		1,605
Employee tax withholdings on stock-based compensation (shares)		(9,472)
Employee tax withholdings on stock-based compensation	(14)			(14)
Net loss	$ (12,288)					(12,288)
Shareholders' equity, at end of period (shares) at Mar. 31, 2017	28,317,490	28,317,490
Shareholders' equity, end of period at Mar. 31, 2017	$ 35,450		$ 153,901	$ (36,081)	$ (4)	$ (82,366)