Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Allowance Rollforward
Trade accounts and notes receivable	$ 558,661	$ 440,926
ASU 2014-09
Allowance Rollforward
Trade accounts and notes receivable			$ (3,600)
Allowances for Accounts Receivable
Allowance Rollforward
Balance at beginning of period	(5,141)	(6,432)	(9,633)
Provision / Additions charged to costs and expenses	(1,774)	(2,348)	(1,064)
Charged to other accounts	(477)	938	2,435
Deductions	1,110	2,701	1,830
Balance at end of period	(6,282)	(5,141)	(6,432)
Valuation Allowance on Deferred Tax Assets
Allowance Rollforward
Balance at beginning of period	(10,183)	(1,112)	(448)
Provision / Additions charged to costs and expenses	(1,585)	(9,071)	(664)
Deductions	0	0	0
Balance at end of period	$ (11,768)	$ (10,183)	$ (1,112)