Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2024	Apr. 30, 2023
Deferred tax assets:
Accrued liabilities and reserves	$ 9,075	$ 7,031
Deferred revenue	15,222	15,565
Accrued bonus compensation	10,272	9,361
Workers compensation	11,281	11,500
Operating and finance lease obligations	55,739	52,464
Asset retirement obligations	10,036	9,404
Deferred compensation	2,909	3,242
Equity compensation	8,018	8,305
State net operating losses and tax credits	2,568	1,807
Other	4,523	3,551
Total gross deferred tax assets	129,643	122,230
Less valuation allowance	550	250
Total net deferred tax assets	129,093	121,980
Deferred tax liabilities:
Property and equipment depreciation	(667,680)	(617,154)
Goodwill	(52,900)	(43,900)
Other	(5,363)	(4,524)
Total gross deferred tax liabilities	(725,943)	(665,578)
Net deferred tax liability	$ (596,850)	$ (543,598)