Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Apr. 30, 2020 USD ($) segment	Apr. 30, 2019 USD ($)	May 01, 2019 USD ($)	Apr. 30, 2018 USD ($)
Property, Plant and Equipment [Line Items]
Cash	$ 8,342,000	$ 3,237,000
Cash equivalents	0	0
Net income (loss)	(1,975,000)	128,000
Accumulated deficit	72,673,000	70,698,000
Working capital	1,400,000
Impairment of long-lived assets	$ 0	0
Number of reportable segments | segment	1
Goodwill Impairment	$ 335,000	0
Goodwill	335,000	669,000
Unrecognized tax benefits	178,000	151,000		$ 151,000
Income tax penalties and interest expense	27,000	0
Provision for (benefit) from income tax	130,000	$ 103,000
Operating lease right-of-use assets, net	$ 2,798,000		$ 3,201,000
Accounting Standards Update 2016-02
Property, Plant and Equipment [Line Items]
Operating lease right-of-use assets, net			3,200,000
Advance rent			900,000
Operating lease, liability			$ 4,100,000
Minimum
Property, Plant and Equipment [Line Items]
Useful life	3 years
Maximum
Property, Plant and Equipment [Line Items]
Useful life	9 years
POS Operations
Property, Plant and Equipment [Line Items]
Segment reporting, revenue percentage	2.50%