Notes Payable and Long-Term Debt - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2021	Aug. 31, 2020	Aug. 31, 2019	Sep. 29, 2021	Jul. 30, 2021	Feb. 19, 2021	Sep. 24, 2020	Aug. 14, 2020	Jun. 26, 2020	Sep. 04, 2018
Debt Instrument [Line Items]
Interest expense	$ 104,565	$ 116,977	$ 167,065
Long-term Debt, Fair Value	1,700,000
Notes payable	1,740,859	1,575,491
Long-term Debt	1,578,422
Capitalized Interest	(8,000)	(10,900)	$ (9,400)
Long-term debt repaid	547,300
Principal Amount Outstanding of Loans Held-in-portfolio	671,900
maximum availability under securitization					$ 700,000		$ 600,000		$ 500,000
Notes Purchase Agreement								$ 375,000
Loans and Leases Receivable, Loans in Process	600,000
additional uncommitted availability	$ 250,000
Unsecured debt | Minimum
Debt Instrument [Line Items]
Interest rate	2.60%
Unsecured debt | Maximum
Debt Instrument [Line Items]
Interest rate	9.00%
Five-year revolving facilities | Line of credit | Revolving credit facility
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	$ 0	345,000
Debt Instrument, Term	5 years
Line of Credit Facility, Current Borrowing Capacity	$ 2,750,000
Uncommitted lines of credit | Line of credit | Revolving credit facility
Debt Instrument [Line Items]
Long-term Line of Credit, Noncurrent	268,000
Other international subsidiaries, lines of credit | Line of credit | Revolving credit facility
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	204,300
Repurchase Facility [Member] | Subordinated Debt [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity										$ 150,000
Line of Credit Facility, Fair Value of Amount Outstanding		150,000
Private placement, payable in equal installments beginning in 2017 through 2021 | Unsecured debt
Debt Instrument [Line Items]
Long-term Debt	$ 0	20,000
Private placement, payable in equal installments beginning in 2017 through 2021 | Notes Payable, Other Payables [Member]
Debt Instrument [Line Items]
Interest rate	4.00%
Debt Instrument, Face Amount	$ 100,000
Other notes and contracts | Secured debt
Debt Instrument [Line Items]
Long-term Debt	33,443	34,709
Notes Payable, Other Payables [Member] | Notes Payable, Other Payables [Member] | Revolving credit facility
Debt Instrument [Line Items]
Notes payable	864,147	763,215
Recourse loan commitments | Notes Payable, Other Payables [Member]
Debt Instrument [Line Items]
Short-term bank loans and notes payable current borrowing capacity	150,000
Notes payable	49,900
Recourse loan commitments | Notes Payable, Other Payables [Member] | Subsequent Event
Debt Instrument [Line Items]
Short-term bank loans and notes payable current borrowing capacity				$ 100,000
Short-Term Notes Payable, Surplus Funds Program [Member] | Notes Payable, Other Payables [Member]
Debt Instrument [Line Items]
Notes payable	132,300
Bilateral, uncommitted revolving facilities [Member] | Line of credit | Revolving credit facility
Debt Instrument [Line Items]
Short-term Debt, Fair Value	335,000	0
Term loans, 430K payable in 2025 [Member] | Unsecured debt
Debt Instrument [Line Items]
Long-term Debt	$ 0	$ 366,000				$ 366,000