Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Nominal or face amount used to calculate payments on the derivative liability.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Derivative Instruments and Hedging Activities (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Apr. 30, 2020
Derivative Instruments and Hedging Activities [Abstract]
Total debt outstanding	$ 846,701		$ 775,025
Unamortized debt issuance costs	600
Variable rate loans outstanding	847,300
Interest Rate Swaps [Member] \| Cash Flow Hedging [Member]
Derivative Instruments and Hedging Activities [Abstract]
Notional amount of derivative liability	300,000		300,000
Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Interest Expense [Member]
Derivative Instruments and Hedging Activities [Abstract]
Net gain (losses) reclassified from Accumulated Other Comprehensive Loss	(900)	$ 200
Interest Rate Swaps [Member] \| Recurring [Member] \| Level 2 [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Derivative Instruments and Hedging Activities [Abstract]
Assets fair value of derivative instrument	$ 8,200		$ 8,300