Notes Payable and Long-Term Debt - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May 31, 2024	May 31, 2023	May 31, 2024	May 31, 2023	Apr. 18, 2024	Aug. 31, 2023
Debt Instrument [Line Items]
Interest expense	$ 23,425	$ 36,949	$ 78,513	$ 106,166
Capitalized interest	6,800	4,100	18,300	9,800
Interest Expense	23,425	$ 36,949	78,513	$ 106,166
Principal Amount Outstanding of Loans Held-in-portfolio	1,000,000		1,000,000
Long-term Debt	1,669,212		1,669,212			$ 1,819,819
interest rate low
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage					5.84%
interest rate high
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage					6.13%
Five-Year Revolving Facilities | Line of Credit | Revolving credit facility
Debt Instrument [Line Items]
Current borrowing capacity	2,800,000		2,800,000
Outstanding balance	0		0			0
Repurchase Facility | Subordinated Debt
Debt Instrument [Line Items]
Outstanding balance	0		0			0
Maximum borrowing capacity	200,000		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			366,000
committed
Debt Instrument [Line Items]
maximum availability under securitization	850,000		850,000
uncommitted
Debt Instrument [Line Items]
maximum availability under securitization	250,000		250,000
loan amount utilized
Debt Instrument [Line Items]
Principal Amount Outstanding of Loans Held-in-portfolio	0		0
Private Placement
Debt Instrument [Line Items]
Long-term Debt	$ 1,413,000		$ 1,413,000		$ 700,000	$ 1,413,000