Auto Loan Receivables (Auto Loan Receivables, Net) (Details) - USD ($) $ in Thousands	Nov. 30, 2020	Aug. 31, 2020	Mar. 01, 2020	Feb. 29, 2020	Nov. 30, 2019	Aug. 31, 2019	Feb. 28, 2019
Total ending managed receivables	$ 13,636,100			$ 13,617,800
Accrued interest and fees	61,900			56,200
Other	1,000			35,500
Less: allowance for loan losses	(431,592)	$ (432,500)	$ (359,800)	(157,796)	$ (153,600)	$ (150,400)	$ (138,200)
Auto loans receivable, net	13,267,364			13,551,711
Asset-backed term funding
Total ending managed receivables	10,878,500			11,007,100
Warehouse facilities
Total ending managed receivables	2,308,000			2,181,700
Overcollateralization
Total ending managed receivables	337,000			289,000
Other managed receivables
Total ending managed receivables	$ 112,600			$ 140,000