Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	May 01, 2019	Apr. 30, 2019
Accounting Policies [Abstract]
Net (loss) income	$ (641)	$ 482
Net cash used in operating activities	279	(336)
Accumulated deficit	71,339			$ 70,698
Working capital deficit	1,600
Cash and cash equivalents	2,202			3,237
Unrecognized tax benefits	151			151
Provision for income taxes	15	$ 0
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets, net	3,103			$ 0
Present value of minimum payments due	$ 11,180
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets, net			$ 3,200
Deferred rent			900
Operating lease liability			4,100
Present value of minimum payments due			$ 4,100