Long-term Debt and Other Credit Arrangements	9 Months Ended
	Jan. 31, 2021
Debt Disclosure [Abstract]
Long-term Debt and Other Credit Arrangements	Long-term Debt and Other Credit ArrangementsAt January 31, 2021, advances of $4.5 million were outstanding under the Company’s revolving credit facility, compared to advances of $4.7 million outstanding as of April 30, 2020. The Company had standby letters of credit outstanding of $512,000 at January 31, 2021, unchanged from April 30, 2020. Amounts available under the revolving credit facility were $8.6 million and $8.7 million at January 31, 2021 and April 30, 2020, respectively. At April 30, 2020, the Company was not in compliance with all of the financial covenants under the revolving credit facility. On July 20, 2020, the Company entered into an amendment which effected changes in certain financial covenants and included a waiver of the non-compliance. On January 28, 2021, the Company entered into another amendment which effected changes (i) extending the maturity date under the Credit Agreement and Revolving Note from February 1, 2021 to May 3, 2021; (ii) establishing a minimum EBITDA covenant for the fiscal quarter ending April 30, 2021 of $1,000,000, determined for the four-quarter period then ending; and (iii) revising the covenant regarding delivery of financial projections to the Bank to, among other things, provide projections for the next succeeding fiscal year. These amendments did not change the amount of availability under the revolving credit facility. At January 31, 2021, the Company was in compliance with all the financial covenants under its revolving credit facility.