CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Series Alpha Convertible Preferred Stock	Series Alpha-1 Convertible Preferred Stock	Series Beta Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
BALANCE at Jan. 31, 2014	$ (39,859)	$ 30,536	$ 3,005			$ 4,487		$ (44,346)
BALANCE, Shares at Jan. 31, 2014		7,848,198	485,143		1,927,177
Issuance of common stock for stock option exercises	19					19
Issuance of common stock for stock option exercises, Shares					135,564
Issuance of stock upon warrant exercise	11	$ 96				11
Issuance of stock upon warrant exercise, Shares		20,407			2,326
Issuance of common stock in conjunction with acquisition	338					338
Issuance of common stock in conjunction with acquisition, Shares					90,246
Vesting of early exercised stock options and restricted stock	68					68
Vesting of early exercised stock options and restricted stock, Shares					359,752
Issuance of common stock warrants in conjunction with debt	262					262
Stock-based compensation	426					426
Net loss	(6,410)							(6,410)
BALANCE at Jan. 31, 2015	(45,145)	$ 30,632	$ 3,005			5,611		(50,756)
BALANCE, Shares at Jan. 31, 2015		7,868,605	485,143		2,515,065
Issuance of stock				$ 5,000
Issuance of stock, Shares				241,469
Conversion of convertible preferred stock to common stock upon initial public offering	38,637	$ (30,632)	$ (3,005)	$ (5,000)	$ 1	38,636
Conversion of convertible preferred stock to common stock upon initial public offering, Shares		(7,868,605)	(485,143)	(241,469)	8,878,857
Issuance of common stock upon initial public offering, net of issuance costs	56,879				$ 1	56,878
Issuance of common stock upon initial public offering, net of issuance costs, Shares					5,000,000
Issuance of common stock for stock option exercises	66					66
Issuance of common stock for stock option exercises, Shares					83,157
De-recognition of preferred warrant liability to additional paid-in capital	1,075					1,075
Issuance of common stock in conjunction with acquisition	451					451
Issuance of common stock in conjunction with acquisition, Shares					49,159
Vesting of early exercised stock options and restricted stock	154					154
Vesting of early exercised stock options and restricted stock, Shares					327,349
Issuance of common stock related to employee stock purchase plan	111					111
Issuance of common stock related to employee stock purchase plan, Shares					15,569
Exercise of common stock warrants to common stock	31					31
Exercise of common stock warrants to common stock, Shares					30,573
Exercise of preferred stock warrants to common stock	13					13
Exercise of preferred stock warrants to common stock, Shares					16,521
Stock-based compensation	4,653					4,653
Other comprehensive income (loss)	17						$ 17
Net loss	(14,052)							(14,052)
BALANCE at Jan. 31, 2016	$ 42,890				$ 2	107,679	17	(64,808)
BALANCE, Shares at Jan. 31, 2016	70,199				16,916,250
Issuance of common stock for stock option exercises	$ 301					301
Issuance of common stock for stock option exercises, Shares	213,164				208,164
Issuance of common stock in conjunction with acquisition	$ 165					165
Issuance of common stock in conjunction with acquisition, Shares					26,375
Vesting of early exercised stock options and restricted stock	81					81
Vesting of early exercised stock options and restricted stock, Shares					123,221
Issuance of common stock related to employee stock purchase plan	1,176					1,176
Issuance of common stock related to employee stock purchase plan, Shares					234,792
Issuance of common stock upon vesting of restricted stock units, Shares					657,034
Shares repurchased for tax withholdings on vesting of restricted stock units	(1,588)					(1,588)
Shares repurchased for tax withholdings on vesting of restricted stock units, Shares					(170,281)
Stock-based compensation	9,772					9,772
Other comprehensive income (loss)	(28)						(28)
Cumulative stock-based compensation forfeiture adjustment						53		(53)
Net loss	(12,949)							(12,949)
BALANCE at Jan. 31, 2017	$ 39,820				$ 2	$ 117,639	$ (11)	$ (77,810)
BALANCE, Shares at Jan. 31, 2017	109,315				17,995,555