Accounting Policies (Narrative) (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Nov. 30, 2017 USD ($)	Nov. 30, 2017 USD ($) warehouse	Nov. 30, 2016 USD ($)	Feb. 28, 2017 USD ($)
Accounting Policies [Abstract]
Cash equivalents	$ 600	$ 600		$ 300
Restricted cash from collections on auto loan receivables	388,945	$ 388,945		380,353
Number of warehouse facilities | warehouse		3
Required benchmark for account delinquency		120 days
Accumulated depreciation and amortization	1,140,000	$ 1,140,000		1,040,000
Restricted cash on deposit in reserve accounts	56,200	56,200		52,800
Restricted investments	75,700	75,700		$ 70,800
Excess Tax Benefit from Share-based Compensation	$ 8,700	13,300	$ 7,100
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		10,000
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		$ 15,000