XML 73 R62.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Accumulated Other Comprehensive Loss (Narrative) (Details) - USD ($) $ in Millions | May 31, 2018 | Feb. 28, 2018
--- | --- | ---
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] |  |
Deferred tax | $ 16.8 | $ 16.6

X
- Definition The balance of deferred taxes on items remaining in accumulated other comprehensive income loss + References No definition available. + Details
Name: | kmx_AccumulatedOtherComprehensiveIncomeLossDeferredTaxes
Namespace Prefix: | kmx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_ComprehensiveIncomeNetOfTaxAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration