Auto Loan Receivables (Auto Loan Receivables, Net) (Details) - USD ($) $ in Thousands	Aug. 31, 2020	May 31, 2020	Mar. 01, 2020	Feb. 29, 2020	Aug. 31, 2019	May 31, 2019	Feb. 28, 2019
Total ending managed receivables	$ 13,379,000			$ 13,617,800
Accrued interest and fees	61,700			56,200
Other	4,900			35,500
Less: allowance for loan losses	(432,546)	$ (437,200)	$ (359,800)	(157,796)	$ (150,400)	$ (147,000)	$ (138,200)
Auto loans receivable, net	13,013,106			13,551,711
Asset-backed term funding
Total ending managed receivables	10,670,900			11,007,100
Warehouse facilities
Total ending managed receivables	2,253,700			2,181,700
Overcollateralization
Total ending managed receivables	312,000			289,000
Other managed receivables
Total ending managed receivables	$ 142,400			$ 140,000