Commitments and Contingencies (Details) - USD ($)	12 Months Ended
Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2020
Future minimum lease payments under noncancelable operating leases
2020	$ 5,298,000
2021	3,527,000
2022	2,723,000
2023	1,554,000
2024	953,000
Total lease payments	14,055,000
Rental expense under operating leases	4,609,000	$ 4,011,000
Letters of credit outstanding	7,079,000		$ 2,716,000
Reserve for incurred cost claim audits	$ 93,000

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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- Definition

Amount of loss contingency liability.

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Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

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