Notes Payable and Long-Term Debt - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Nov. 30, 2023	Nov. 30, 2022	Aug. 31, 2023
Debt Instrument [Line Items]
Interest expense	$ 29,628	$ 33,250
Capitalized interest	5,000	2,500
Interest Expense	29,628	$ 33,250
Principal Amount Outstanding of Loans Held-in-portfolio	974,200
Long-term Debt	1,817,770		$ 1,819,819
Five-Year Revolving Facilities | Line of Credit | Revolving credit facility
Debt Instrument [Line Items]
Current borrowing capacity	2,800,000
Outstanding balance	0		0
Repurchase Facility | Subordinated Debt
Debt Instrument [Line Items]
Outstanding balance	0		0
Maximum borrowing capacity	200,000
Term loans from cooperatives and other banks, 430K payable in 2025 | Unsecured Debt
Debt Instrument [Line Items]
Long-term Debt	366,000		366,000
committed
Debt Instrument [Line Items]
maximum availability under securitization	850,000
uncommitted
Debt Instrument [Line Items]
maximum availability under securitization	250,000
loan amount utilized
Debt Instrument [Line Items]
Principal Amount Outstanding of Loans Held-in-portfolio	0
Private Placement
Debt Instrument [Line Items]
Long-term Debt	$ 1,413,000		$ 1,413,000