Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Deferred tax assets:
Accrued liabilities and reserves	$ 7,031	$ 11,699
Deferred revenue	15,565	11,893
Accrued bonus compensation	9,361	7,340
Workers compensation	11,500	9,922
Operating and finance lease obligations	52,464	46,693
Asset retirement obligations	9,404	7,361
Deferred compensation	3,242	3,540
Equity compensation	8,305	9,567
State net operating losses and tax credits	1,807	4,021
Other	3,551	3,548
Total gross deferred tax assets	122,230	115,584
Less valuation allowance	250	250
Total net deferred tax assets	121,980	115,334
Deferred tax liabilities:
Property and equipment depreciation	(617,154)	(597,740)
Goodwill	(43,900)	(34,869)
Other	(4,524)	(3,197)
Total gross deferred tax liabilities	(665,578)	(635,806)
Net deferred tax liability	$ (543,598)	$ (520,472)