CarMax (KMX) 10-Q 5 Oct 18 2019 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Aug. 31, 2018	Sep. 28, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Aug. 31, 2018
Document Fiscal Year Focus	2,019
Document Fiscal Period Focus	Q2
Entity Registrant Name	CARMAX INC
Entity Central Index Key	1,170,010
Entity Current Reporting Status	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Current Fiscal Year End Date	--02-28
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		174,621,243

Consolidated Statements Of Earn

Consolidated Statements Of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
SALES AND OPERATING REVENUES:
NET SALES AND OPERATING REVENUES	$ 4,766,035	$ 4,386,640	$ 9,558,627	$ 8,928,974
TOTAL COST OF SALES	4,115,399	3,782,635	8,246,651	7,676,031
GROSS PROFIT	650,636	604,005	1,311,976	1,252,943
CARMAX AUTO FINANCE INCOME	109,667	107,936	225,260	217,299
Selling, general and administrative expenses	453,554	405,062	891,788	808,565
Interest expense	17,950	16,836	36,002	33,674
Other (income) expense	(686)	(189)	277	(282)
Earnings before income taxes	289,485	290,232	609,169	628,285
Income tax provision	68,595	108,808	149,623	235,159
NET EARNINGS	$ 220,890	$ 181,424	$ 459,546	$ 393,126
WEIGHTED AVERAGE COMMON SHARES:
Basic, shares	176,284	182,868	177,211	184,034
Diluted, shares	178,200	184,696	178,811	185,778
NET EARNINGS PER SHARE:
Basic (in dollars per share)	$ 1.25	$ 0.99	$ 2.59	$ 2.14
Diluted (in dollars per share)	$ 1.24	$ 0.98	$ 2.57	$ 2.12
Used vehicle sales
SALES AND OPERATING REVENUES:
NET SALES AND OPERATING REVENUES	$ 3,975,368	$ 3,694,200	$ 7,996,415	$ 7,537,573
TOTAL COST OF SALES	3,546,383	3,289,051	7,127,992	6,700,497
Wholesale vehicle sales
SALES AND OPERATING REVENUES:
NET SALES AND OPERATING REVENUES	627,990	547,767	1,245,641	1,101,157
TOTAL COST OF SALES	516,913	447,490	1,019,858	896,208
Total other sales and revenues
SALES AND OPERATING REVENUES:
NET SALES AND OPERATING REVENUES	162,677	144,673	316,571	290,244
TOTAL COST OF SALES	$ 52,103	$ 46,094	$ 98,801	$ 79,326
NET SALES AND OPERATING REVENUES
Percentage of Sales
Item as a percent of net sales and operating revenues	100.00%	100.00%	100.00%	100.00%
TOTAL COST OF SALES
Percentage of Sales
Item as a percent of net sales and operating revenues	86.30%	86.20%	86.30%	86.00%
GROSS PROFIT
Percentage of Sales
Item as a percent of net sales and operating revenues	13.70%	13.80%	13.70%	14.00%
CARMAX AUTO FINANCE INCOME
Percentage of Sales
Item as a percent of net sales and operating revenues	2.30%	2.50%	2.40%	2.40%
Selling, general and administrative expenses
Percentage of Sales
Item as a percent of net sales and operating revenues	9.50%	9.20%	9.30%	9.10%
Interest expense
Percentage of Sales
Item as a percent of net sales and operating revenues	0.40%	0.40%	0.40%	0.40%
Other (income) expense
Percentage of Sales
Item as a percent of net sales and operating revenues	0.00%	0.00%	0.00%	0.00%
Earnings before income taxes
Percentage of Sales
Item as a percent of net sales and operating revenues	6.10%	6.60%	6.40%	7.00%
Income tax provision
Percentage of Sales
Item as a percent of net sales and operating revenues	1.40%	2.50%	1.60%	2.60%
NET EARNINGS
Percentage of Sales
Item as a percent of net sales and operating revenues	4.60%	4.10%	4.80%	4.40%
NET SALES AND OPERATING REVENUES | Used vehicle sales
Percentage of Sales
Item as a percent of net sales and operating revenues	83.40%	84.20%	83.70%	84.40%
NET SALES AND OPERATING REVENUES | Wholesale vehicle sales
Percentage of Sales
Item as a percent of net sales and operating revenues	13.20%	12.50%	13.00%	12.30%
NET SALES AND OPERATING REVENUES | Total other sales and revenues
Percentage of Sales
Item as a percent of net sales and operating revenues	3.40%	3.30%	3.30%	3.30%
TOTAL COST OF SALES | Used vehicle sales
Percentage of Sales
Item as a percent of net sales and operating revenues	74.40%	75.00%	74.60%	75.00%
TOTAL COST OF SALES | Wholesale vehicle sales
Percentage of Sales
Item as a percent of net sales and operating revenues	10.80%	10.20%	10.70%	10.00%
TOTAL COST OF SALES | Total other sales and revenues
Percentage of Sales
Item as a percent of net sales and operating revenues	1.10%	1.10%	1.00%	0.90%

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
Statement of Comprehensive Income [Abstract]
NET EARNINGS	$ 220,890	$ 181,424	$ 459,546	$ 393,126
Other comprehensive income (loss), net of taxes
Net change in retirement benefit plan unrecognized actuarial losses	370	275	739	549
Net change in cash flow hedge unrecognized gains	240	(1,673)	(862)	(3,621)
Other comprehensive income (loss), net of taxes	610	(1,398)	(123)	(3,072)
TOTAL COMPREHENSIVE INCOME	$ 221,500	$ 180,026	$ 459,423	$ 390,054

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Aug. 31, 2018	Feb. 28, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 37,147	$ 44,525
Restricted cash from collections on auto loan receivables	447,642	399,442
Accounts receivable, net	104,883	133,321
Inventory	2,357,355	2,390,694
Other current assets	75,060	93,462
TOTAL CURRENT ASSETS	3,022,087	3,061,444
Auto loan receivables, net	12,140,455	11,535,704
Property and equipment, net of accumulated depreciation of $1,230,012 and $1,164,249 as of August 31, 2018 and February 28, 2018, respectively	2,766,902	2,667,061
Deferred income taxes	56,354	63,256
Other assets	190,707	158,807
TOTAL ASSETS	18,176,505	17,486,272
CURRENT LIABILITIES:
Accounts payable	605,535	529,733
Accrued expenses and other current liabilities	266,214	278,771
Short-term debt	3,296	127
Current portion of finance and capital lease obligations	10,579	9,994
Current portion of non-recourse notes payable	397,837	355,433
TOTAL CURRENT LIABILITIES	1,283,461	1,174,058
Long-term debt, excluding current portion	840,187	995,479
Finance and capital lease obligations, excluding current portion	505,167	490,369
Non-recourse notes payable, excluding current portion	11,831,967	11,266,964
Other liabilities	233,605	242,553
TOTAL LIABILITIES	14,694,387	14,169,423
Commitments and contingent liabilities
SHAREHOLDERS’ EQUITY:
Common stock, $0.50 par value; 350,000,000 shares authorized; 175,289,632 and 179,747,894 shares issued and outstanding as of August 31, 2018 and February 28, 2018, respectively	87,645	89,874
Capital in excess of par value	1,265,930	1,234,047
Accumulated other comprehensive loss	(54,435)	(54,312)
Retained earnings	2,182,978	2,047,240
TOTAL SHAREHOLDERS’ EQUITY	3,482,118	3,316,849
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 18,176,505	$ 17,486,272

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Aug. 31, 2018	Feb. 28, 2018
Statement of Financial Position [Abstract]
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$ 1,230,012	$ 1,164,249
Common stock, par value (in dollars per share)	$ 0.5	$ 0.5
Common stock, shares authorized	350,000,000	350,000,000
Common stock, shares issued	175,289,632	179,747,894
Common stock, shares outstanding	175,289,632	179,747,894

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017
OPERATING ACTIVITIES:
Net earnings	$ 459,546	$ 393,126
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	90,311	88,078
Share-based compensation expense	54,234	36,585
Provision for loan losses	70,863	61,465
Provision for cancellation reserves	38,699	34,488
Deferred income tax provision	2,539	2,271
Other	1,358	1,013
Net decrease (increase) in:
Accounts receivable, net	28,438	52,655
Inventory	33,339	28,794
Other current assets	22,161	(1,063)
Auto loan receivables, net	(675,614)	(637,719)
Other assets	(7,167)	83
Net increase (decrease) in:
Accounts payable, accrued expenses and other current liabilities and accrued income taxes	57,639	66,939
Other liabilities	(65,461)	(45,618)
NET CASH PROVIDED BY OPERATING ACTIVITIES	110,885	81,097
INVESTING ACTIVITIES:
Capital expenditures	(171,111)	(155,110)
Proceeds from disposal of property and equipment	565	96
Purchases of investments	(5,306)	(1,344)
Sales of investments	904	370
NET CASH USED IN INVESTING ACTIVITIES	(174,948)	(155,988)
FINANCING ACTIVITIES:
Increase in short-term debt, net	3,169	209
Proceeds from issuances of long-term debt	1,300,600	1,552,000
Payments on long-term debt	(1,456,100)	(1,689,000)
Cash paid for debt issuance costs	(8,189)	(7,623)
Payments on finance and capital lease obligations	(4,819)	(4,475)
Issuances of non-recourse notes payable	5,486,502	4,987,000
Payments on non-recourse notes payable	(4,878,974)	(4,425,923)
Repurchase and retirement of common stock	(381,347)	(344,785)
Equity issuances	47,502	23,905
NET CASH PROVIDED BY FINANCING ACTIVITIES	108,344	91,308
Increase in cash, cash equivalents and restricted cash	44,281	16,417
Cash, cash equivalents and restricted cash at beginning of year	554,898	523,865
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT END OF PERIOD	599,179	540,282
RECONCILIATION OF CASH, CASH EQUIVALENTS AND RESTRICTED CASH TO THE CONSOLIDATED BALANCE SHEETS:
Cash and cash equivalents	37,147	25,765
Restricted cash from collections on auto loan receivables	447,642	404,276
Restricted cash included in other assets	114,390	110,241
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT END OF PERIOD	$ 599,179	$ 540,282

Background

Background	6 Months Ended
	Aug. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business Description and Accounting Policies [Text Block]	Background Business. CarMax, Inc. (“we,” “our,” “us,” “CarMax” and “the company”), including its wholly owned subsidiaries, is the largest retailer of used vehicles in the United States. We operate in two reportable segments: CarMax Sales Operations and CarMax Auto Finance (“CAF”). Our CarMax Sales Operations segment consists of all aspects of our auto merchandising and service operations, excluding financing provided by CAF. Our CAF segment consists solely of our own finance operation that provides financing to customers buying retail vehicles from CarMax. We deliver an unrivaled customer experience by offering a broad selection of high quality used vehicles and related products and services at low, no-haggle prices using a customer-friendly sales process in an attractive, modern sales facility, as well as through carmax.com and our mobile apps. We provide customers with a range of related products and services, including the appraisal and purchase of vehicles directly from consumers; the financing of retail vehicle purchases through CAF and third-party finance providers; the sale of extended protection plan (“EPP”) products, which include extended service plans (“ESPs”) and guaranteed asset protection (“GAP”); and vehicle repair service. Vehicles purchased through the appraisal process that do not meet our retail standards are sold to licensed dealers through on-site wholesale auctions. Basis of Presentation and Use of Estimates. The accompanying interim unaudited consolidated financial statements include the accounts of CarMax and our wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. These consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) for interim financial information. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, such interim consolidated financial statements reflect all normal recurring adjustments considered necessary to present fairly the financial position and the results of operations and cash flows for the interim periods presented. The results of operations for the interim periods are not necessarily indicative of the results to be expected for the full fiscal year. The accounting policies followed in the presentation of our interim financial results are consistent with those included in the company's Annual Report on Form 10-K for the fiscal year ended February 28, 2018 (the “2018 Annual Report”), with the exception of those related to recent accounting pronouncements adopted in the current fiscal year. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and footnotes included in our 2018 Annual Report. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates. Certain prior year amounts have been reclassified to conform to the current year’s presentation. Amounts and percentages may not total due to rounding. On March 1, 2018, we adopted Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) 2014-09 related to revenue recognition using the modified retrospective transition method for all contracts. Results for reporting periods beginning after March 1, 2018, are presented under ASU 2014-09, while comparative period amounts have not been restated and continue to be presented under the previous accounting standard. See Note 2 for further details. In connection with our adoption of FASB ASU 2016-18 during the current fiscal year, restricted cash is now included with cash and cash equivalents in the reconciliation of beginning of year and end of period total amounts in the consolidated statements of cash flows. Prior period amounts have been reclassified to conform to the current period's presentation, resulting in a decrease in cash used by investing activities of $29.1 million for the six months ended August 31, 2017 . Recent Accounting Pronouncements. Effective in Future Periods . In February 2016, the FASB issued an accounting pronouncement (FASB ASU 2016-02) related to the accounting for leases. This pronouncement, along with subsequent ASUs issued to clarify certain provisions of ASU 2016-02, requires lessees to record most leases on their balance sheet while also disclosing key information about those lease arrangements. Under the new guidance, lease classification as either a finance lease or an operating lease will affect the pattern and classification of expense recognition in the income statement. The classification criteria to distinguish between finance and operating leases are generally consistent with the classification criteria to distinguish between capital and operating leases under existing lease accounting guidance. This pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2018. We plan to adopt the new standard for our fiscal year beginning March 1, 2019, using the modified retrospective transition approach; specifically, using the optional transition method provided by the accounting pronouncement (FASB ASU 2018-11), which allows for transition through a cumulative-effect adjustment at the beginning of the period of adoption. We expect to record a $400 million to $430 million increase in both assets and liabilities on our opening consolidated balance sheets as a result of recognizing new right-of-use assets and lease liabilities as of March 1, 2019 . This estimate is based on our lease portfolio as of February 28, 2018 , and it does not include the potential impacts of remeasurement due to changes in our assessment of the lease term subsequent to our adoption of the standard. The ultimate impact of adopting this pronouncement will depend on our lease portfolio and other factors as of the transition date. We do not expect this standard to have a material impact on our sale-leaseback transactions currently accounted for as direct financings, and we believe most of our leases will maintain their current lease classification under the new standard. As a result, we do not expect the new standard to have a material effect on our expense recognition pattern or, in turn, our consolidated statements of operations. We are continuing to evaluate the full impact of the new standard, as well as its impacts on our business processes, systems, and internal controls. In June 2016, the FASB issued an accounting pronouncement (FASB ASU 2016-13) related to the measurement of credit losses on financial instruments. The pronouncement changes the impairment model for most financial assets and will require the use of an “expected loss” model for instruments measured at amortized cost. Under this model, entities will be required to estimate the lifetime expected credit loss on such instruments and record an allowance to offset the amortized cost basis of the financial asset, resulting in a net presentation of the amount expected to be collected on the financial asset. This pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2019. We plan to adopt this pronouncement for our fiscal year beginning March 1, 2020. We are currently evaluating the effect on our consolidated financial statements, as well as the impacts on our business processes, systems and internal controls, and expect that the standard will have a material impact on our calculation of the allowance for loan losses. In August 2018, the FASB issued an accounting pronouncement (FASB ASU 2018-13) related to disclosure requirements for fair value measurements. The pronouncement eliminates, modifies and adds disclosure requirements for fair value measurements. The pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted. We are currently in the process of evaluating the effects of this pronouncement on our consolidated financial statements, including potential early adoption. In August 2018, the FASB issued an accounting pronouncement (FASB ASU 2018-14) related to disclosure requirements for defined benefit plans. The pronouncement eliminates, modifies and adds disclosure requirements for defined benefit plans. The pronouncement is effective for fiscal years ending after December 15, 2020, and early adoption is permitted. We are currently in the process of evaluating the effects of this pronouncement on our consolidated financial statements, including potential early adoption. In August 2018, the FASB issued an accounting pronouncement (FASB ASU 2018-15) related to customers’ accounting for implementation costs incurred in a cloud computing arrangement that is considered a service contract. This pronouncement aligns the requirements for capitalizing implementation costs in such arrangements with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted, including adoption in any interim period for which financial statements have not been issued. Entities can choose to adopt the new guidance prospectively or retrospectively. We are currently in the process of evaluating the effects of this pronouncement on our consolidated financial statements, including potential early adoption.

Revenue

Revenue	6 Months Ended
	Aug. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	We recognize revenue when control of the good or service has been transferred to the customer, generally either at the time of sale or upon delivery to a customer. Our contracts have a fixed contract price and revenue is measured as the amount of consideration we expect to receive in exchange for transferring goods or providing services. We collect sales taxes and other taxes from customers on behalf of governmental authorities at the time of sale. These taxes are accounted for on a net basis and are not included in net sales and operating revenues or cost of sales. We generally expense sales commissions when incurred because the amortization period would have been less than one year. These costs are recorded within selling, general and administrative expenses. We do not have any significant payment terms as payment is received at or shortly after the point of sale. On March 1, 2018, we adopted FASB ASU 2014-09 related to revenue recognition using the modified retrospective transition method for all contracts. In connection with the adoption of this standard, we recorded a net after-tax cumulative-effect adjustment to increase beginning retained earnings by $12.9 million to recognize profit-sharing revenues on ESP contracts sold on or before February 28, 2018, with corresponding adjustments to other assets and deferred income taxes. The adoption also resulted in $4.4 million and $8.4 million recorded in other sales and revenues on our consolidated statement of earnings for the three and six months ended August 31, 2018 , respectively, relating to additional profit-sharing revenues to which we expect to be entitled. Lastly, the adoption resulted in a $14.1 million increase to other current assets and accrued expenses and other current liabilities as of August 31, 2018 related to estimated vehicle sales returns, which were previously shown on a net basis. Disaggregation of Revenue Three Months Ended August 31 Six Months Ended August 31 (In millions) 2018 2017 2018 2017 Used vehicle sales $ 3,975.4 $ 3,694.2 $ 7,996.4 $ 7,537.6 Wholesale vehicle sales 628.0 547.8 1,245.6 1,101.2 Other sales and revenues: Extended protection plan revenues 98.5 85.5 198.6 177.4 Third-party finance fees, net (9.7 ) (11.6 ) (24.2 ) (23.0 ) Service revenues 36.1 34.5 72.7 68.2 Other 37.8 36.3 69.5 67.6 Total other sales and revenues 162.7 144.7 316.6 290.2 Total net sales and operating revenues $ 4,766.0 $ 4,386.6 $ 9,558.6 $ 8,929.0 Used Vehicle Sales. We sell used vehicles at our retail stores, and revenue from the sale of these vehicles is recognized upon transfer of control of the vehicle to the customer. As part of our customer service strategy, we guarantee the retail vehicles we sell with a 5-day, money-back guarantee. We record a reserve for estimated returns based on historical experience and trends. The reserve for estimated returns is presented gross on the consolidated balance sheets, with a return asset recorded in other current assets and a refund liability recorded in accrued expenses and other current liabilities. We also guarantee the used vehicles we sell with at least a 30-day limited warranty. These warranties are deemed assurance-type warranties and accounted for as warranty obligations. See Note 14 for additional information on this warranty and its related obligation. Wholesale Vehicle Sales. Wholesale vehicles are sold at our auctions, and revenue from the sale of these vehicles is recognized upon transfer of control of the vehicle to the customer. Dealers also pay a fee to us based on the sale price of the vehicles they purchase. This fee is recognized as revenue at the time of sale. While we provide condition disclosures on each wholesale vehicle sold, the vehicles are subject to a limited right of return. We record a reserve for estimated returns based on historical experience and trends. The reserve for estimated returns is presented gross on the consolidated balance sheets, with a return asset recorded in other current assets and a refund liability recorded in accrued expenses and other current liabilities. EPP Revenues. We also sell ESP and GAP products on behalf of unrelated third parties, who are primarily responsible for fulfilling the contract, to customers who purchase a retail vehicle. The ESPs we currently offer on all used vehicles provide coverage up to 60 months (subject to mileage limitations), while GAP covers the customer for the term of their finance contract. We recognize revenue, on a net basis, at the time of sale. We also record a reserve for estimated contract cancellations. The reserve for cancellations is evaluated for each product and is based on forecasted forward cancellation curves utilizing historical experience, recent trends and credit mix of the customer base. Our risk related to contract cancellations is limited to the revenue that we receive. Cancellations fluctuate depending on the volume of EPP sales, customer financing default or prepayment rates, and shifts in customer behavior, including those related to changes in the coverage or term of the product. The current portion of estimated cancellation reserves is recognized as a component of accrued expenses and other current liabilities with the remaining amount recognized in other liabilities. See Note 7 for additional information on cancellation reserves. We are contractually entitled to receive profit-sharing revenues based on the performance of the ESPs administered by third parties. These revenues are a form of variable consideration included in the ESP transaction price to the extent that it is probable that it will not result in a significant revenue reversal. An estimate of the amount to which we expect to be entitled, subject to various constraints, is recognized upon satisfying the performance obligation of selling the ESP. These constraints include factors that are outside of the company’s influence or control and the length of time until settlement. We apply the expected value method, utilizing historical claims and cancellation data from CarMax customers, as well as other qualitative assumptions. This estimate is reassessed each reporting period with changes reflected in other sales and revenues on our consolidated statements of earnings and other assets on our consolidated balance sheets. Profit-sharing payments by the ESP provider begin when the underlying ESPs reach a specified level of claims history. As of August 31, 2018 , we have recognized a long-term contract asset of $25.7 million related to cumulative profit-sharing payments to which we expect to be entitled, which is included in other assets on our consolidated balance sheets. Third-Party Finance Fees. Customers applying for financing who are not approved or are conditionally approved by CAF are generally evaluated by other third-party finance providers. These providers generally either pay us or are paid a fixed, pre-negotiated fee per contract. We recognize these fees at the time of sale. Service Revenues. Service revenue consists of labor and parts income related to vehicle repair service, including repairs of vehicles covered under an ESP we sell or warranty program. Service revenue is recognized at the time the work is completed. Other Revenues. Other revenues consist primarily of new vehicle sales at our two new car franchise locations and sales of accessories. Revenue in this category is recognized upon transfer of control to the customer.

CarMax Auto Finance

CarMax Auto Finance	6 Months Ended
	Aug. 31, 2018
CarMax Auto Finance Income [Abstract]
CarMax Auto Finance	CarMax Auto Finance CAF provides financing to qualified retail customers purchasing vehicles from CarMax. CAF provides us the opportunity to capture additional profits, cash flows and sales while managing our reliance on third-party finance sources. Management regularly analyzes CAF's operating results by assessing profitability, the performance of the auto loan receivables, including trends in credit losses and delinquencies, and CAF direct expenses. This information is used to assess CAF's performance and make operating decisions, including resource allocation. We typically use securitizations to fund loans originated by CAF. CAF income primarily reflects the interest and fee income generated by the auto loan receivables less the interest expense associated with the debt issued to fund these receivables, a provision for estimated loan losses and direct CAF expenses. CAF income does not include any allocation of indirect costs. Although CAF benefits from certain indirect overhead expenditures, we have not allocated indirect costs to CAF to avoid making subjective allocation decisions. Examples of indirect costs not allocated to CAF include retail store expenses and corporate expenses. In addition, except for auto loan receivables, which are disclosed in Note 4, CAF assets are not separately reported nor do we allocate assets to CAF because such allocation would not be useful to management in making operating decisions. Components of CAF Income Three Months Ended August 31 Six Months Ended August 31 (In millions) 2018 % (1) 2017 % (1) 2018 % (1) 2017 % (1) Interest margin: Interest and fee income $ 242.2 8.0 $ 213.6 7.7 $ 474.5 8.0 $ 420.3 7.7 Interest expense (69.1 ) (2.3 ) (52.2 ) (1.9 ) (132.9 ) (2.2 ) (101.2 ) (1.8 ) Total interest margin 173.1 5.7 161.4 5.8 341.6 5.7 319.1 5.8 Provision for loan losses (40.0 ) (1.3 ) (32.9 ) (1.2 ) (70.9 ) (1.2 ) (61.5 ) (1.1 ) Total interest margin after provision for loan losses 133.1 4.4 128.5 4.6 270.7 4.5 257.6 4.7 Total other expense (0.3 ) — — — (0.3 ) — — — Direct expenses: Payroll and fringe benefit expense (9.6 ) (0.3 ) (8.8 ) (0.3 ) (19.2 ) (0.3 ) (17.3 ) (0.3 ) Other direct expenses (13.5 ) (0.4 ) (11.8 ) (0.4 ) (25.9 ) (0.4 ) (23.0 ) (0.4 ) Total direct expenses (23.1 ) (0.8 ) (20.6 ) (0.7 ) (45.1 ) (0.8 ) (40.3 ) (0.7 ) CarMax Auto Finance income $ 109.7 3.6 $ 107.9 3.9 $ 225.3 3.8 $ 217.3 4.0 Total average managed receivables $ 12,067.5 $ 11,112.0 $ 11,921.4 $ 10,970.8 (1) Annualized percentage of total average managed receivables.

Auto Loan Receivables

Auto Loan Receivables	6 Months Ended
	Aug. 31, 2018
Loans Receivable, Net [Abstract]
Auto Loan Receivables	Auto Loan Receivables Auto loan receivables include amounts due from customers related to retail vehicle sales financed through CAF and are presented net of an allowance for estimated loan losses. We generally use warehouse facilities to fund auto loan receivables originated by CAF until we elect to fund them through an asset-backed term funding transaction, such as a term securitization or alternative funding arrangement. We recognize transfers of auto loan receivables into the warehouse facilities and asset-backed term funding transactions (together, “non-recourse funding vehicles”) as secured borrowings, which result in recording the auto loan receivables and the related non-recourse notes payable on our consolidated balance sheets. The majority of the auto loan receivables serve as collateral for the related non-recourse notes payable of $12.25 billion as of August 31, 2018 and $11.64 billion as of February 28, 2018 . See Note 9 for additional information on non-recourse notes payable. Auto Loan Receivables, Net As of August 31 As of February 28 (In millions) 2018 2018 Asset-backed term funding $ 9,748.3 $ 9,455.2 Warehouse facilities 2,106.0 1,834.0 Overcollateralization (1) 284.5 269.4 Other managed receivables (2) 75.3 60.3 Total ending managed receivables 12,214.1 11,618.9 Accrued interest and fees 51.6 43.2 Other 12.9 2.2 Less allowance for loan losses (138.1 ) (128.6 ) Auto loan receivables, net $ 12,140.5 $ 11,535.7 (1) Represents receivables restricted as excess collateral for the non-recourse funding vehicles. (2) Other managed receivables includes receivables not funded through the non-recourse funding vehicles. Credit Quality. When customers apply for financing, CAF’s proprietary scoring models rely on the customers’ credit history and certain application information to evaluate and rank their risk. We obtain credit histories and other credit data that includes information such as number, age, type of and payment history for prior or existing credit accounts. The application information that is used includes income, collateral value and down payment. The scoring models yield credit grades that represent the relative likelihood of repayment. Customers assigned a grade of “A” are determined to have the highest probability of repayment, and customers assigned a lower grade are determined to have a lower probability of repayment. For loans that are approved, the credit grade influences the terms of the agreement, such as the required loan-to-value ratio and interest rate. CAF uses a combination of the initial credit grades and historical performance to monitor the credit quality of the auto loan receivables on an ongoing basis. We validate the accuracy of the scoring models periodically. Loan performance is reviewed on a recurring basis to identify whether the assigned grades adequately reflect the customers’ likelihood of repayment. Ending Managed Receivables by Major Credit Grade As of August 31 As of February 28 (In millions) 2018 (1) % (2) 2018 (1) % (2) A $ 6,031.2 49.4 $ 5,725.1 49.3 B 4,376.9 35.8 4,133.8 35.6 C and other 1,806.0 14.8 1,760.0 15.1 Total ending managed receivables $ 12,214.1 100.0 $ 11,618.9 100.0 (1) Classified based on credit grade assigned when customers were initially approved for financing. (2) Percent of total ending managed receivables. Allowance for Loan Losses Three Months Ended August 31 Six Months Ended August 31 (In millions) 2018 % (1) 2017 % (1) 2018 % (1) 2017 % (1) Balance as of beginning of period $ 134.3 1.13 $ 129.8 1.18 $ 128.6 1.11 $ 123.6 1.16 Charge-offs (64.9 ) (60.4 ) (123.8 ) (114.5 ) Recoveries 28.7 27.2 62.4 58.9 Provision for loan losses 40.0 32.9 70.9 61.5 Balance as of end of period $ 138.1 1.13 $ 129.5 1.15 $ 138.1 1.13 $ 129.5 1.15 (1) Percent of total ending managed receivables. The allowance for loan losses represents an estimate of the amount of net losses inherent in our portfolio of managed receivables as of the applicable reporting date and anticipated to occur during the following 12 months. The allowance is primarily based on the composition of the portfolio of managed receivables, historical loss trends and forecasted forward loss curves. We also take into account recent trends in delinquencies and defaults, recovery rates and the economic environment. The provision for loan losses is the periodic expense of maintaining an adequate allowance. Past Due Receivables As of August 31 As of February 28 (In millions) 2018 % (1) 2018 % (1) Total ending managed receivables $ 12,214.1 100.0 $ 11,618.9 100.0 Delinquent loans: 31-60 days past due $ 262.8 2.1 $ 246.6 2.1 61-90 days past due 124.4 1.0 116.9 1.0 Greater than 90 days past due 31.8 0.3 29.7 0.3 Total past due $ 419.0 3.4 $ 393.2 3.4 (1) Percent of total ending managed receivables.

Derivative Instruments And Hedg

Derivative Instruments And Hedging Activities	6 Months Ended
	Aug. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments And Hedging Activities	Derivative Instruments and Hedging Activities We use derivatives to manage certain risks arising from both our business operations and economic conditions, particularly with regard to issuances of debt. Primary exposures include LIBOR and other rates used as benchmarks in our securitizations and other debt financing. We enter into derivative instruments to manage exposures related to the future known receipt or payment of uncertain cash amounts, the values of which are impacted by interest rates, and designate these derivative instruments as cash flow hedges for accounting purposes. Our derivative instruments are used to manage (i) differences in the amount of our known or expected cash receipts and our known or expected cash payments principally related to the funding of our auto loan receivables, and (ii) exposure to variable interest rates associated with our term loan. For the derivatives associated with our non-recourse funding vehicles, the effective portion of changes in the fair value is initially recorded in accumulated other comprehensive loss (“AOCL”). For the majority of these derivatives, the amounts are subsequently reclassified into CAF income in the period that the hedged forecasted transaction affects earnings, which occurs as interest expense is recognized on those future issuances of debt. During the next 12 months, we estimate that an additional $6.6 million will be reclassified in AOCL as an increase to CAF income. As of August 31, 2018 and February 28, 2018 , we had interest rate swaps outstanding with a combined notional amount of $2.37 billion and $2.16 billion , respectively, that were designated as cash flow hedges of interest rate risk. See Note 6 for discussion of fair values of financial instruments and Note 12 for the effect on comprehensive income.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Aug. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants in the principal market or, if none exists, the most advantageous market, for the specific asset or liability at the measurement date (referred to as the “exit price”). The fair value should be based on assumptions that market participants would use, including a consideration of nonperformance risk. We assess the inputs used to measure fair value using the three-tier hierarchy. The hierarchy indicates the extent to which inputs used in measuring fair value are observable in the market. Level 1 Inputs include unadjusted quoted prices in active markets for identical assets or liabilities that we can access at the measurement date. Level 2 Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly, including quoted prices for similar assets in active markets, quoted prices from identical or similar assets in inactive markets and observable inputs such as interest rates and yield curves. Level 3 Inputs that are significant to the measurement that are not observable in the market and include management's judgments about the assumptions market participants would use in pricing the asset or liability (including assumptions about risk). Our fair value processes include controls that are designed to ensure that fair values are appropriate. Such controls include model validation, review of key model inputs, analysis of period-over-period fluctuations and reviews by senior management. Valuation Methodologies Money Market Securities. Money market securities are cash equivalents, which are included in cash and cash equivalents, restricted cash from collections on auto loan receivables and other assets. They consist of highly liquid investments with original maturities of three months or less and are classified as Level 1. Mutual Fund Investments. Mutual fund investments consist of publicly traded mutual funds that primarily include diversified equity investments in large-, mid- and small-cap domestic and international companies or investment grade debt securities. The investments, which are included in other assets, are held in a rabbi trust established to fund informally our executive deferred compensation plan and are classified as Level 1. Derivative Instruments. The fair values of our derivative instruments are included in either other current assets, other assets or accounts payable. As described in Note 5, as part of our risk management strategy, we utilize derivative instruments to manage differences in the amount of our known or expected cash receipts and our known or expected cash payments principally related to the funding of our auto loan receivables as well as to manage exposure to variable interest rates on our term loan. Our derivatives are not exchange-traded and are over-the-counter customized derivative instruments. All of our derivative exposures are with highly rated bank counterparties. We measure derivative fair values assuming that the unit of account is an individual derivative instrument and that derivatives are sold or transferred on a stand-alone basis. We estimate the fair value of our derivatives using quotes determined by the derivative counterparties and third-party valuation services. Quotes from third-party valuation services and quotes received from bank counterparties project future cash flows and discount the future amounts to a present value using market-based expectations for interest rates and the contractual terms of the derivative instruments. The models do not require significant judgment and model inputs can typically be observed in a liquid market; however, because the models include inputs other than quoted prices in active markets, all derivatives are classified as Level 2. Our derivative fair value measurements consider assumptions about counterparty and our own nonperformance risk. We monitor counterparty and our own nonperformance risk and, in the event that we determine that a party is unlikely to perform under terms of the contract, we would adjust the derivative fair value to reflect the nonperformance risk. Items Measured at Fair Value on a Recurring Basis As of August 31, 2018 (In thousands) Level 1 Level 2 Total Assets: Money market securities $ 343,551 $ — $ 343,551 Mutual fund investments 20,552 — 20,552 Derivative instruments — 3,988 3,988 Total assets at fair value $ 364,103 $ 3,988 $ 368,091 Percent of total assets at fair value 98.9 % 1.1 % 100.0 % Percent of total assets 2.0 % — % 2.0 % Liabilities: Derivative instruments $ — $ (1,275 ) $ (1,275 ) Total liabilities at fair value $ — $ (1,275 ) $ (1,275 ) Percent of total liabilities — % — % — % As of February 28, 2018 (In thousands) Level 1 Level 2 Total Assets: Money market securities $ 276,894 $ — $ 276,894 Mutual fund investments 19,429 — 19,429 Derivative instruments — 12,127 12,127 Total assets at fair value $ 296,323 $ 12,127 $ 308,450 Percent of total assets at fair value 96.1 % 3.9 % 100.0 % Percent of total assets 1.7 % 0.1 % 1.8 % Liabilities: Derivative instruments $ — $ (99 ) $ (99 ) Total liabilities at fair value $ — $ (99 ) $ (99 ) Percent of total liabilities — % — % — % There were no transfers between Levels 1 and 2 for the three and six months ended August 31, 2018 . As of August 31, 2018 and February 28, 2018 , we had no Level 3 assets. Fair Value of Financial Instruments The carrying value of our cash and cash equivalents, accounts receivable, other restricted cash deposits and accounts payable approximates fair value due to the short-term nature and/or variable rates associated with these financial instruments. Auto loan receivables are presented net of an allowance for estimated loan losses. We believe that the carrying value of our revolving credit facility and term loan approximates fair value due to the variable rates associated with these obligations. The fair value of our senior unsecured notes, which are not carried at fair value on our consolidated balance sheets, was determined using Level 2 inputs based on quoted market prices. The carrying value and fair value of the senior unsecured notes as of August 31, 2018 and February 28, 2018 , respectively, are as follows: (In thousands) As of August 31, 2018 As of February 28, 2018 Carrying value $ 500,000 $ 500,000 Fair value $ 486,149 $ 492,163

Cancellation Reserves

Cancellation Reserves	6 Months Ended
	Aug. 31, 2018
Cancellation Reserves [Abstract]
Cancellation Reserves	Cancellation Reserves We recognize revenue for EPP products, on a net basis, at the time of sale. We also record a reserve for estimated contract cancellations. Cancellations of these services may result from early termination by the customer, or default or prepayment on the finance contract. The reserve for cancellations is evaluated for each product and is based on forecasted forward cancellation curves utilizing historical experience, recent trends and credit mix of the customer base. Cancellation Reserves Three Months Ended August 31 Six Months Ended August 31 (In millions) 2018 2017 2018 2017 Balance as of beginning of period $ 108.7 $ 109.0 $ 105.2 $ 108.2 Cancellations (16.7 ) (16.6 ) (33.3 ) (32.9 ) Provision for future cancellations 18.6 17.4 38.7 34.5 Balance as of end of period $ 110.6 $ 109.8 $ 110.6 $ 109.8 The current portion of estimated cancellation reserves is recognized as a component of accrued expenses and other current liabilities with the remaining amount recognized in other liabilities. As of August 31, 2018 and February 28, 2018 , the current portion of cancellation reserves was $58.3 million and $56.0 million , respectively.

Income Taxes

Income Taxes	6 Months Ended
	Aug. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Tax Cuts and Jobs Act of 2017 (the “2017 Tax Act”) was enacted on December 22, 2017, and, among other changes, reduced the federal statutory tax rate from 35.0% to 21.0%. In accordance with U.S. GAAP for income taxes, as well as SEC Staff Accounting Bulletin No. 118 (“SAB 118”), the company made a reasonable estimate of the impacts of the 2017 Tax Act and recorded this estimate in its results for the year ended February 28, 2018. The company will continue to evaluate the impacts as additional clarification and implementation guidance related to the 2017 Tax Act is released. SAB 118 allows for a measurement period of up to one year, from the date of enactment, to complete the company’s accounting for the impacts of the 2017 Tax Act. As of August 31, 2018 , no additional adjustments have been made to the provisional amounts recorded as of February 28, 2018. The company’s income tax provision for the six months ended August 31, 2018 , includes estimates related to its interpretation of the 2017 Tax Act. These estimates may change as additional clarification and implementation guidance is released. We had $30.1 million of gross unrecognized tax benefits as of August 31, 2018 , and $28.7 million as of February 28, 2018 . There were no significant changes to the gross unrecognized tax benefits as reported for the year ended February 28, 2018 .

Debt

Debt	6 Months Ended
	Aug. 31, 2018
Debt Disclosure [Abstract]
Debt	Debt As of August 31 As of February 28 (In thousands) 2018 2018 Revolving credit facility $ 45,296 $ 197,627 Term loan 300,000 300,000 3.86% Senior notes due 2023 100,000 100,000 4.17% Senior notes due 2026 200,000 200,000 4.27% Senior notes due 2028 200,000 200,000 Finance and capital lease obligations 515,746 500,363 Non-recourse notes payable 12,252,143 11,644,615 Total debt 13,613,185 13,142,605 Less: current portion (411,712 ) (365,554 ) Less: unamortized debt issuance costs (24,152 ) (24,239 ) Long-term debt, net $ 13,177,321 $ 12,752,812 Revolving Credit Facility. We have a $1.20 billion unsecured revolving credit facility (the “credit facility”) with various financial institutions that expires in August 2020 . Borrowings under the credit facility are available for working capital and general corporate purposes. Borrowings accrue interest at variable rates based on LIBOR, the federal funds rate, or the prime rate, depending on the type of borrowing, and we pay a commitment fee on the unused portions of the available funds. Borrowings under the credit facility are either due “on demand” or at maturity depending on the type of borrowing. Borrowings with “on demand” repayment terms are presented as short-term debt, while amounts due at maturity are presented as long-term debt as no repayments are expected to be made within the next 12 months. As of August 31, 2018 , the unused capacity of $1.15 billion was fully available to us. Term Loan. We have a $300 million unsecured term loan that expires in August 2020 . The term loan accrues interest at variable rates based on the LIBOR rate, the federal funds rate, or the prime rate, and interest is payable monthly. As of August 31, 2018 , $300 million remained outstanding and is classified as long-term debt, as no repayments are scheduled to be made within the next 12 months. Borrowings under the term loan are available for working capital and general corporate purposes. Senior Notes. We have senior unsecured notes with outstanding principal totaling $500 million as of August 31, 2018 , which are due in 2023, 2026 and 2028. These notes are classified as long-term debt as no repayments are scheduled to be made within the next 12 months. Borrowings under these notes are available for working capital and general corporate purposes. Interest on the notes is payable semi-annually. Finance and Capital Lease Obligations. Finance and capital lease obligations relate primarily to stores subject to sale-leaseback transactions that did not qualify for sale accounting, and therefore, are accounted for as direct financings. The leases were structured at varying interest rates and generally have initial lease terms ranging from 15 to 20 years with payments made monthly. Payments on the leases are recognized as interest expense and a reduction of the obligations. We have not entered into any new sale-leaseback transactions since fiscal 2009. In the event the leases are modified or extended beyond their original lease term, the related obligation is increased based on the present value of the revised future lease payments, with a corresponding increase to the assets subject to these transactions. Upon modification, the amortization of the obligation is reset, resulting in more of the lease payments being applied to interest expense in the initial years following the modification. See Note 13 for additional information on finance and capital lease obligations. Non-Recourse Notes Payable. The non-recourse notes payable relate to auto loan receivables funded through non-recourse funding vehicles. The timing of principal payments on the non-recourse notes payable is based on the timing of principal collections and defaults on the related auto loan receivables. The current portion of non-recourse notes payable represents principal payments that are due to be distributed in the following period. As of August 31, 2018 , $10.15 billion of non-recourse notes payable was outstanding related to asset-backed term funding transactions. These notes payable accrue interest predominantly at fixed rates and have scheduled maturities through April 2025 , but may mature earlier, depending upon the repayment rate of the underlying auto loan receivables. As of August 31, 2018 , $2.11 billion of non-recourse notes payable was outstanding related to our warehouse facilities. As of August 31, 2018 , the combined limit of our warehouse facilities was $3.14 billion , and the unused warehouse capacity totaled $1.03 billion . Of the combined limit, $1.70 billion will expire in February 2019 and $1.30 billion will expire in August 2019 . Subsequent to the end of the quarter, the limit on the remaining $140 million facility was increased to $150 million and the expiration date was extended from September 2018 to September 2019. The return requirements of warehouse facility investors could fluctuate significantly depending on market conditions. At renewal, the cost, structure and capacity of the facilities could change. These changes could have a significant impact on our funding costs. See Note 4 for additional information on the related auto loan receivables. Capitalized Interest. We capitalize interest in connection with the construction of certain facilities. For the six months ended August 31, 2018 and 2017 , we capitalized interest of $3.1 million and $3.7 million , respectively. Financial Covenants. The credit facility, term loan and senior note agreements contain representations and warranties, conditions and covenants. We must also meet financial covenants in conjunction with certain of the sale-leaseback transactions. The agreements governing our non-recourse funding vehicles contain representations and warranties, financial covenants and performance triggers. As of August 31, 2018 , we were in compliance with all financial covenants and our non-recourse funding vehicles were in compliance with the related performance triggers.

Stock and Stock-Based Incentive

Stock and Stock-Based Incentive Plans Stock And Stock-Based Incentive Plans	6 Months Ended
	Aug. 31, 2018
Share-based Compensation [Abstract]
Stock and Stock-Based Incentive Plans	Stock and Stock-Based Incentive Plans (A) Share Repurchase Program As of August 31, 2018 , a total of $750 million of board authorizations for repurchases of our common stock were outstanding, with no expiration date. At that date, $638.3 million remained available for repurchase. Common Stock Repurchases Three Months Ended Six Months Ended August 31 August 31 2018 2017 2018 2017 Number of shares repurchased (in thousands) 2,291.7 2,453.1 5,599.3 5,487.8 Average cost per share $ 74.70 $ 63.78 $ 67.61 $ 61.69 Available for repurchase, as of end of period (in millions) $ 638.3 $ 1,251.8 $ 638.3 $ 1,251.8 (B) Share-Based Compensation Composition of Share-Based Compensation Expense Three Months Ended Six Months Ended August 31 August 31 (In thousands) 2018 2017 2018 2017 Cost of sales $ 1,603 $ 1,076 $ 2,894 $ 1,303 CarMax Auto Finance income 1,237 848 2,434 1,668 Selling, general and administrative expenses 22,775 16,316 49,752 34,409 Share-based compensation expense, before income taxes $ 25,615 $ 18,240 $ 55,080 $ 37,380 Composition of Share-Based Compensation Expense – By Grant Type Three Months Ended Six Months Ended August 31 August 31 (In thousands) 2018 2017 2018 2017 Nonqualified stock options $ 6,493 $ 5,916 $ 17,608 $ 16,286 Cash-settled restricted stock units (RSUs) 15,540 9,785 27,894 12,903 Stock-settled market stock units (MSUs) 2,643 2,543 7,279 6,164 Other share-based incentives: Stock-settled performance stock units (PSUs) 320 (863 ) 726 490 Restricted stock (RSAs) (54 ) 478 433 742 Stock-settled deferred stock units (DSUs) 294 — 294 — Employee stock purchase plan 379 381 846 795 Total other share-based incentives $ 939 $ (4 ) $ 2,299 $ 2,027 Share-based compensation expense, before income taxes $ 25,615 $ 18,240 $ 55,080 $ 37,380 (C) Stock Incentive Plan Information Share/Unit Activity Six Months Ended August 31, 2018 Equity Classified Liability Classified (Shares/units in thousands) Options MSUs Other RSUs Outstanding as of February 28, 2018 7,762 419 271 1,460 Granted 1,738 204 23 629 Exercised or vested and converted (1,072 ) (94 ) (93 ) (339 ) Cancelled (256 ) (15 ) (39 ) (74 ) Outstanding as of August 31, 2018 8,172 514 162 1,676 Weighted average grant date fair value per share/unit: Granted $ 18.74 $ 81.99 $ 73.22 $ 63.06 Ending outstanding $ 16.51 $ 74.25 $ 57.45 $ 58.01 As of August 31, 2018 Unrecognized compensation ( in mil lions ) $ 49.8 $ 18.2 $ 3.0

Net Earnings Per Share

Net Earnings Per Share	6 Months Ended
	Aug. 31, 2018
Earnings Per Share [Abstract]
Net Earnings Per Share	Net Earnings Per Share Basic net earnings per share is computed by dividing net earnings available for basic common shares by the weighted average number of shares of common stock outstanding. Diluted net earnings per share is computed by dividing net earnings available for diluted common shares by the sum of weighted average number of shares of common stock outstanding and dilutive potential common stock. Diluted net earnings per share is calculated using the “if-converted” treasury stock method. Basic and Dilutive Net Earnings Per Share Reconciliations Three Months Ended Six Months Ended August 31 August 31 (In thousands except per share data) 2018 2017 2018 2017 Net earnings $ 220,890 $ 181,424 $ 459,546 $ 393,126 Weighted average common shares outstanding 176,284 182,868 177,211 184,034 Dilutive potential common shares: Stock options 1,462 1,465 1,194 1,337 Stock-settled stock units and awards 454 363 406 407 Weighted average common shares and dilutive potential common shares 178,200 184,696 178,811 185,778 Basic net earnings per share $ 1.25 $ 0.99 $ 2.59 $ 2.14 Diluted net earnings per share $ 1.24 $ 0.98 $ 2.57 $ 2.12 Certain options to purchase shares of common stock were outstanding and not included in the calculation of diluted net earnings per share because their inclusion would have been antidilutive. On a weighted average basis, for the three months ended August 31, 2018 and 2017 , options to purchase 2,210,917 shares and 3,130,285 shares of common stock, respectively, were not included. For the six months ended August 31, 2018 and 2017 , options to purchase 3,805,873 shares and 2,854,557 shares of common stock, respectively, were not included.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	6 Months Ended
	Aug. 31, 2018
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Changes in Accumulated Other Comprehensive Loss By Component Total Net Accumulated Unrecognized Net Other Actuarial Unrecognized Comprehensive (In thousands, net of income taxes) Losses Hedge Gains Loss Balance as of February 28, 2018 $ (68,497 ) $ 14,185 $ (54,312 ) Other comprehensive income before reclassifications — 1,325 1,325 Amounts reclassified from accumulated other comprehensive loss 739 (2,187 ) (1,448 ) Other comprehensive income (loss) 739 (862 ) (123 ) Balance as of August 31, 2018 $ (67,758 ) $ 13,323 $ (54,435 ) Changes In and Reclassifications Out of Accumulated Other Comprehensive Loss Three Months Ended August 31 Six Months Ended August 31 (In thousands) 2018 2017 2018 2017 Retirement Benefit Plans: Actuarial loss amortization reclassifications recognized in net pension expense: Cost of sales $ 204 $ 187 $ 405 $ 372 CarMax Auto Finance income 12 11 25 22 Selling, general and administrative expenses 271 255 544 513 Total amortization reclassifications recognized in net pension expense 487 453 974 907 Tax expense (117 ) (178 ) (235 ) (358 ) Amortization reclassifications recognized in net pension expense, net of tax 370 275 739 549 Net change in retirement benefit plan unrecognized actuarial losses, net of tax 370 275 739 549 Cash Flow Hedges (Note 5): Effective portion of changes in fair value 2,187 (3,712 ) 1,800 (7,938 ) Tax (expense) benefit (577 ) 1,461 (475 ) 3,125 Effective portion of changes in fair value, net of tax 1,610 (2,251 ) 1,325 (4,813 ) Reclassifications to CarMax Auto Finance income (1,861 ) 952 (2,970 ) 1,965 Tax benefit (expense) 491 (374 ) 783 (773 ) Reclassification of hedge (gains) losses, net of tax (1,370 ) 578 (2,187 ) 1,192 Net change in cash flow hedge unrecognized gains, net of tax 240 (1,673 ) (862 ) (3,621 ) Total other comprehensive income (loss), net of tax $ 610 $ (1,398 ) $ (123 ) $ (3,072 ) Changes in the funded status of our retirement plans and the effective portion of changes in the fair value of derivatives that are designated and qualify as cash flow hedges are recognized in accumulated other comprehensive loss. The cumulative balances are net of deferred taxes of $16.6 million as of August 31, 2018 and February 28, 2018 .

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	6 Months Ended
	Aug. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	Supplemental Cash Flow Information Supplemental disclosures of cash flow information: Six Months Ended August 31 (In thousands) 2018 2017 Non-cash investing and financing activities: Decrease in accrued capital expenditures $ (5,509 ) $ (2,864 ) Increase in finance and capital lease obligations $ 19,605 $ 10,245

Contingent Liabilities

Contingent Liabilities	6 Months Ended
	Aug. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Contingent Liabilities	Contingent Liabilities Litigation . CarMax entities are defendants in four proceedings asserting wage and hour claims with respect to CarMax sales consultants in California. The asserted claims include failure to pay minimum wage, provide meal periods and rest breaks, pay statutory/contractual wages, reimburse for work-related expenses and provide accurate itemized wage statements; unfair competition; and Private Attorney General Act claims. On September 4, 2015, Craig Weiss et al., v. CarMax Auto Superstores California, LLC, and CarMax Auto Superstores West Coast, Inc., a putative class action, was filed in the Superior Court of California, County of Placer. The Weiss lawsuit seeks civil penalties, fines, cost of suit, and the recovery of attorneys’ fees. On June 29, 2016, Ryan Gomez et al. v. CarMax Auto Superstores California, LLC, and CarMax Auto Superstores West Coast, Inc., a putative class action, was filed in the Superior Court of the State of California, Los Angeles. The Gomez lawsuit seeks declaratory relief, unspecified damages, restitution, statutory penalties, interest, cost and attorneys’ fees. On September 7, 2016, James Rowland v. CarMax Auto Superstores California, LLC, and CarMax Auto Superstores West Coast, Inc., a putative class action, was filed in the U.S. District Court, Eastern District of California, Sacramento Division. The Rowland lawsuit seeks unspecified damages, restitution, statutory penalties, interest, cost and attorneys’ fees. On October 31, 2017, Joshua Sabanovich v. CarMax Superstores California, LLC et. al., a putative class action, was filed in the Superior Court of California, County of Stanislaus. The Sabanovich lawsuit seeks unspecified damages, restitution, statutory penalties, interest, cost and attorneys’ fees. We are unable to make a reasonable estimate of the amount or range of loss that could result from an unfavorable outcome in these matters. On April 25, 2017, the company met with representatives from multiple California municipality district attorney offices as part of an informal inquiry by those offices into the handling, storage and disposal of certain types of hazardous waste at our store locations in those municipalities. We are unable to make a reasonable estimate of the amount or range of loss that could result from an unfavorable outcome in these matters. We are involved in various other legal proceedings in the normal course of business. Based upon our evaluation of information currently available, we believe that the ultimate resolution of any such proceedings will not have a material adverse effect, either individually or in the aggregate, on our financial condition, results of operations or cash flows. Other Matters. In accordance with the terms of real estate lease agreements, we generally agree to indemnify the lessor from certain liabilities arising as a result of the use of the leased premises, including environmental liabilities and repairs to leased property upon termination of the lease. Additionally, in accordance with the terms of agreements entered into for the sale of properties, we generally agree to indemnify the buyer from certain liabilities and costs arising subsequent to the date of the sale, including environmental liabilities and liabilities resulting from the breach of representations or warranties made in accordance with the agreements. We do not have any known material environmental commitments, contingencies or other indemnification issues arising from these arrangements. As part of our customer service strategy, we guarantee the used vehicles we retail with at least a 30-day limited warranty. A vehicle in need of repair within this period will be repaired free of charge. As a result, each vehicle sold has an implied liability associated with it. Accordingly, based on historical trends, we record a provision for estimated future repairs during the guarantee period for each vehicle sold. The liability for this guarantee was $7.3 million as of August 31, 2018 , and $6.1 million as of February 28, 2018 , and is included in accrued expenses and other current liabilities.

Background Basis of Accounting

Background Basis of Accounting (Policies)	6 Months Ended
	Aug. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background	Business. CarMax, Inc. (“we,” “our,” “us,” “CarMax” and “the company”), including its wholly owned subsidiaries, is the largest retailer of used vehicles in the United States. We operate in two reportable segments: CarMax Sales Operations and CarMax Auto Finance (“CAF”). Our CarMax Sales Operations segment consists of all aspects of our auto merchandising and service operations, excluding financing provided by CAF. Our CAF segment consists solely of our own finance operation that provides financing to customers buying retail vehicles from CarMax. We deliver an unrivaled customer experience by offering a broad selection of high quality used vehicles and related products and services at low, no-haggle prices using a customer-friendly sales process in an attractive, modern sales facility, as well as through carmax.com and our mobile apps. We provide customers with a range of related products and services, including the appraisal and purchase of vehicles directly from consumers; the financing of retail vehicle purchases through CAF and third-party finance providers; the sale of extended protection plan (“EPP”) products, which include extended service plans (“ESPs”) and guaranteed asset protection (“GAP”); and vehicle repair service. Vehicles purchased through the appraisal process that do not meet our retail standards are sold to licensed dealers through on-site wholesale auctions.
Basis of Presentation	Basis of Presentation and Use of Estimates. The accompanying interim unaudited consolidated financial statements include the accounts of CarMax and our wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. These consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) for interim financial information. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, such interim consolidated financial statements reflect all normal recurring adjustments considered necessary to present fairly the financial position and the results of operations and cash flows for the interim periods presented. The results of operations for the interim periods are not necessarily indicative of the results to be expected for the full fiscal year. The accounting policies followed in the presentation of our interim financial results are consistent with those included in the company's Annual Report on Form 10-K for the fiscal year ended February 28, 2018 (the “2018 Annual Report”), with the exception of those related to recent accounting pronouncements adopted in the current fiscal year. These consolidated financial statements should be read in conjunction with the audited consolidated financial statements and footnotes included in our 2018 Annual Report.
Use of Estimates	The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates. Certain prior year amounts have been reclassified to conform to the current year’s presentation. Amounts and percentages may not total due to rounding.
Recent Accounting Pronouncements	Recent Accounting Pronouncements. Effective in Future Periods . In February 2016, the FASB issued an accounting pronouncement (FASB ASU 2016-02) related to the accounting for leases. This pronouncement, along with subsequent ASUs issued to clarify certain provisions of ASU 2016-02, requires lessees to record most leases on their balance sheet while also disclosing key information about those lease arrangements. Under the new guidance, lease classification as either a finance lease or an operating lease will affect the pattern and classification of expense recognition in the income statement. The classification criteria to distinguish between finance and operating leases are generally consistent with the classification criteria to distinguish between capital and operating leases under existing lease accounting guidance. This pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2018. We plan to adopt the new standard for our fiscal year beginning March 1, 2019, using the modified retrospective transition approach; specifically, using the optional transition method provided by the accounting pronouncement (FASB ASU 2018-11), which allows for transition through a cumulative-effect adjustment at the beginning of the period of adoption. We expect to record a $400 million to $430 million increase in both assets and liabilities on our opening consolidated balance sheets as a result of recognizing new right-of-use assets and lease liabilities as of March 1, 2019 . This estimate is based on our lease portfolio as of February 28, 2018 , and it does not include the potential impacts of remeasurement due to changes in our assessment of the lease term subsequent to our adoption of the standard. The ultimate impact of adopting this pronouncement will depend on our lease portfolio and other factors as of the transition date. We do not expect this standard to have a material impact on our sale-leaseback transactions currently accounted for as direct financings, and we believe most of our leases will maintain their current lease classification under the new standard. As a result, we do not expect the new standard to have a material effect on our expense recognition pattern or, in turn, our consolidated statements of operations. We are continuing to evaluate the full impact of the new standard, as well as its impacts on our business processes, systems, and internal controls. In June 2016, the FASB issued an accounting pronouncement (FASB ASU 2016-13) related to the measurement of credit losses on financial instruments. The pronouncement changes the impairment model for most financial assets and will require the use of an “expected loss” model for instruments measured at amortized cost. Under this model, entities will be required to estimate the lifetime expected credit loss on such instruments and record an allowance to offset the amortized cost basis of the financial asset, resulting in a net presentation of the amount expected to be collected on the financial asset. This pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2019. We plan to adopt this pronouncement for our fiscal year beginning March 1, 2020. We are currently evaluating the effect on our consolidated financial statements, as well as the impacts on our business processes, systems and internal controls, and expect that the standard will have a material impact on our calculation of the allowance for loan losses. In August 2018, the FASB issued an accounting pronouncement (FASB ASU 2018-13) related to disclosure requirements for fair value measurements. The pronouncement eliminates, modifies and adds disclosure requirements for fair value measurements. The pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted. We are currently in the process of evaluating the effects of this pronouncement on our consolidated financial statements, including potential early adoption. In August 2018, the FASB issued an accounting pronouncement (FASB ASU 2018-14) related to disclosure requirements for defined benefit plans. The pronouncement eliminates, modifies and adds disclosure requirements for defined benefit plans. The pronouncement is effective for fiscal years ending after December 15, 2020, and early adoption is permitted. We are currently in the process of evaluating the effects of this pronouncement on our consolidated financial statements, including potential early adoption. In August 2018, the FASB issued an accounting pronouncement (FASB ASU 2018-15) related to customers’ accounting for implementation costs incurred in a cloud computing arrangement that is considered a service contract. This pronouncement aligns the requirements for capitalizing implementation costs in such arrangements with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted, including adoption in any interim period for which financial statements have not been issued. Entities can choose to adopt the new guidance prospectively or retrospectively. We are currently in the process of evaluating the effects of this pronouncement on our consolidated financial statements, including potential early adoption.

Revenue Revenue (Tables)

Revenue Revenue (Tables)	6 Months Ended
	Aug. 31, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	Disaggregation of Revenue Three Months Ended August 31 Six Months Ended August 31 (In millions) 2018 2017 2018 2017 Used vehicle sales $ 3,975.4 $ 3,694.2 $ 7,996.4 $ 7,537.6 Wholesale vehicle sales 628.0 547.8 1,245.6 1,101.2 Other sales and revenues: Extended protection plan revenues 98.5 85.5 198.6 177.4 Third-party finance fees, net (9.7 ) (11.6 ) (24.2 ) (23.0 ) Service revenues 36.1 34.5 72.7 68.2 Other 37.8 36.3 69.5 67.6 Total other sales and revenues 162.7 144.7 316.6 290.2 Total net sales and operating revenues $ 4,766.0 $ 4,386.6 $ 9,558.6 $ 8,929.0

CarMax Auto Finance (Tables)

CarMax Auto Finance (Tables)	6 Months Ended
	Aug. 31, 2018
CarMax Auto Finance Income [Abstract]
Components Of CarMax Auto Finance Income	Components of CAF Income Three Months Ended August 31 Six Months Ended August 31 (In millions) 2018 % (1) 2017 % (1) 2018 % (1) 2017 % (1) Interest margin: Interest and fee income $ 242.2 8.0 $ 213.6 7.7 $ 474.5 8.0 $ 420.3 7.7 Interest expense (69.1 ) (2.3 ) (52.2 ) (1.9 ) (132.9 ) (2.2 ) (101.2 ) (1.8 ) Total interest margin 173.1 5.7 161.4 5.8 341.6 5.7 319.1 5.8 Provision for loan losses (40.0 ) (1.3 ) (32.9 ) (1.2 ) (70.9 ) (1.2 ) (61.5 ) (1.1 ) Total interest margin after provision for loan losses 133.1 4.4 128.5 4.6 270.7 4.5 257.6 4.7 Total other expense (0.3 ) — — — (0.3 ) — — — Direct expenses: Payroll and fringe benefit expense (9.6 ) (0.3 ) (8.8 ) (0.3 ) (19.2 ) (0.3 ) (17.3 ) (0.3 ) Other direct expenses (13.5 ) (0.4 ) (11.8 ) (0.4 ) (25.9 ) (0.4 ) (23.0 ) (0.4 ) Total direct expenses (23.1 ) (0.8 ) (20.6 ) (0.7 ) (45.1 ) (0.8 ) (40.3 ) (0.7 ) CarMax Auto Finance income $ 109.7 3.6 $ 107.9 3.9 $ 225.3 3.8 $ 217.3 4.0 Total average managed receivables $ 12,067.5 $ 11,112.0 $ 11,921.4 $ 10,970.8 (1) Annualized percentage of total average managed receivables.

Auto Loan Receivables (Tables)

Auto Loan Receivables (Tables)	6 Months Ended
	Aug. 31, 2018
Loans Receivable, Net [Abstract]
Auto Loan Receivables, Net	Auto Loan Receivables, Net As of August 31 As of February 28 (In millions) 2018 2018 Asset-backed term funding $ 9,748.3 $ 9,455.2 Warehouse facilities 2,106.0 1,834.0 Overcollateralization (1) 284.5 269.4 Other managed receivables (2) 75.3 60.3 Total ending managed receivables 12,214.1 11,618.9 Accrued interest and fees 51.6 43.2 Other 12.9 2.2 Less allowance for loan losses (138.1 ) (128.6 ) Auto loan receivables, net $ 12,140.5 $ 11,535.7 (1) Represents receivables restricted as excess collateral for the non-recourse funding vehicles. (2) Other managed receivables includes receivables not funded through the non-recourse funding vehicles.
Ending Managed Receivables By Major Credit Grade	Ending Managed Receivables by Major Credit Grade As of August 31 As of February 28 (In millions) 2018 (1) % (2) 2018 (1) % (2) A $ 6,031.2 49.4 $ 5,725.1 49.3 B 4,376.9 35.8 4,133.8 35.6 C and other 1,806.0 14.8 1,760.0 15.1 Total ending managed receivables $ 12,214.1 100.0 $ 11,618.9 100.0 (1) Classified based on credit grade assigned when customers were initially approved for financing. (2) Percent of total ending managed receivables.
Allowance For Loan Losses	Allowance for Loan Losses Three Months Ended August 31 Six Months Ended August 31 (In millions) 2018 % (1) 2017 % (1) 2018 % (1) 2017 % (1) Balance as of beginning of period $ 134.3 1.13 $ 129.8 1.18 $ 128.6 1.11 $ 123.6 1.16 Charge-offs (64.9 ) (60.4 ) (123.8 ) (114.5 ) Recoveries 28.7 27.2 62.4 58.9 Provision for loan losses 40.0 32.9 70.9 61.5 Balance as of end of period $ 138.1 1.13 $ 129.5 1.15 $ 138.1 1.13 $ 129.5 1.15 (1) Percent of total ending managed receivables.
Past Due Receivables	Past Due Receivables As of August 31 As of February 28 (In millions) 2018 % (1) 2018 % (1) Total ending managed receivables $ 12,214.1 100.0 $ 11,618.9 100.0 Delinquent loans: 31-60 days past due $ 262.8 2.1 $ 246.6 2.1 61-90 days past due 124.4 1.0 116.9 1.0 Greater than 90 days past due 31.8 0.3 29.7 0.3 Total past due $ 419.0 3.4 $ 393.2 3.4 (1) Percent of total ending managed receivables.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Aug. 31, 2018
Fair Value Disclosures [Abstract]
Schedule Of Items Measured At Fair Value On A Recurring Basis	Items Measured at Fair Value on a Recurring Basis As of August 31, 2018 (In thousands) Level 1 Level 2 Total Assets: Money market securities $ 343,551 $ — $ 343,551 Mutual fund investments 20,552 — 20,552 Derivative instruments — 3,988 3,988 Total assets at fair value $ 364,103 $ 3,988 $ 368,091 Percent of total assets at fair value 98.9 % 1.1 % 100.0 % Percent of total assets 2.0 % — % 2.0 % Liabilities: Derivative instruments $ — $ (1,275 ) $ (1,275 ) Total liabilities at fair value $ — $ (1,275 ) $ (1,275 ) Percent of total liabilities — % — % — % As of February 28, 2018 (In thousands) Level 1 Level 2 Total Assets: Money market securities $ 276,894 $ — $ 276,894 Mutual fund investments 19,429 — 19,429 Derivative instruments — 12,127 12,127 Total assets at fair value $ 296,323 $ 12,127 $ 308,450 Percent of total assets at fair value 96.1 % 3.9 % 100.0 % Percent of total assets 1.7 % 0.1 % 1.8 % Liabilities: Derivative instruments $ — $ (99 ) $ (99 ) Total liabilities at fair value $ — $ (99 ) $ (99 ) Percent of total liabilities — % — % — %
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]	(In thousands) As of August 31, 2018 As of February 28, 2018 Carrying value $ 500,000 $ 500,000 Fair value $ 486,149 $ 492,163

Cancellation Reserves (Tables)

Cancellation Reserves (Tables)	6 Months Ended
	Aug. 31, 2018
Cancellation Reserves [Abstract]
Schedule Of Cancellation Reserves Accrual	Cancellation Reserves Three Months Ended August 31 Six Months Ended August 31 (In millions) 2018 2017 2018 2017 Balance as of beginning of period $ 108.7 $ 109.0 $ 105.2 $ 108.2 Cancellations (16.7 ) (16.6 ) (33.3 ) (32.9 ) Provision for future cancellations 18.6 17.4 38.7 34.5 Balance as of end of period $ 110.6 $ 109.8 $ 110.6 $ 109.8

Debt (Tables)

Debt (Tables)	6 Months Ended
	Aug. 31, 2018
Debt Disclosure [Abstract]
Schedule Of Debt	Debt As of August 31 As of February 28 (In thousands) 2018 2018 Revolving credit facility $ 45,296 $ 197,627 Term loan 300,000 300,000 3.86% Senior notes due 2023 100,000 100,000 4.17% Senior notes due 2026 200,000 200,000 4.27% Senior notes due 2028 200,000 200,000 Finance and capital lease obligations 515,746 500,363 Non-recourse notes payable 12,252,143 11,644,615 Total debt 13,613,185 13,142,605 Less: current portion (411,712 ) (365,554 ) Less: unamortized debt issuance costs (24,152 ) (24,239 ) Long-term debt, net $ 13,177,321 $ 12,752,812

Stock and Stock-Based Incenti_2

Stock and Stock-Based Incentive Plans (Tables)	6 Months Ended
	Aug. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Common Stock Repurchases	Common Stock Repurchases Three Months Ended Six Months Ended August 31 August 31 2018 2017 2018 2017 Number of shares repurchased (in thousands) 2,291.7 2,453.1 5,599.3 5,487.8 Average cost per share $ 74.70 $ 63.78 $ 67.61 $ 61.69 Available for repurchase, as of end of period (in millions) $ 638.3 $ 1,251.8 $ 638.3 $ 1,251.8
Composition of Share-Based Compensation Expense	Composition of Share-Based Compensation Expense Three Months Ended Six Months Ended August 31 August 31 (In thousands) 2018 2017 2018 2017 Cost of sales $ 1,603 $ 1,076 $ 2,894 $ 1,303 CarMax Auto Finance income 1,237 848 2,434 1,668 Selling, general and administrative expenses 22,775 16,316 49,752 34,409 Share-based compensation expense, before income taxes $ 25,615 $ 18,240 $ 55,080 $ 37,380
Composition Of Share-Based Compensation Expense - By Grant Type	Composition of Share-Based Compensation Expense – By Grant Type Three Months Ended Six Months Ended August 31 August 31 (In thousands) 2018 2017 2018 2017 Nonqualified stock options $ 6,493 $ 5,916 $ 17,608 $ 16,286 Cash-settled restricted stock units (RSUs) 15,540 9,785 27,894 12,903 Stock-settled market stock units (MSUs) 2,643 2,543 7,279 6,164 Other share-based incentives: Stock-settled performance stock units (PSUs) 320 (863 ) 726 490 Restricted stock (RSAs) (54 ) 478 433 742 Stock-settled deferred stock units (DSUs) 294 — 294 — Employee stock purchase plan 379 381 846 795 Total other share-based incentives $ 939 $ (4 ) $ 2,299 $ 2,027 Share-based compensation expense, before income taxes $ 25,615 $ 18,240 $ 55,080 $ 37,380
Share-based Compensation, Activity [Table Text Block]	Six Months Ended August 31, 2018 Equity Classified Liability Classified (Shares/units in thousands) Options MSUs Other RSUs Outstanding as of February 28, 2018 7,762 419 271 1,460 Granted 1,738 204 23 629 Exercised or vested and converted (1,072 ) (94 ) (93 ) (339 ) Cancelled (256 ) (15 ) (39 ) (74 ) Outstanding as of August 31, 2018 8,172 514 162 1,676 Weighted average grant date fair value per share/unit: Granted $ 18.74 $ 81.99 $ 73.22 $ 63.06 Ending outstanding $ 16.51 $ 74.25 $ 57.45 $ 58.01 As of August 31, 2018 Unrecognized compensation ( in mil lions ) $ 49.8 $ 18.2 $ 3.0

Net Earnings Per Share (Tables)

Net Earnings Per Share (Tables)	6 Months Ended
	Aug. 31, 2018
Earnings Per Share [Abstract]
Basic And Dilutive Net Earnings Per Share Reconciliations	Basic and Dilutive Net Earnings Per Share Reconciliations Three Months Ended Six Months Ended August 31 August 31 (In thousands except per share data) 2018 2017 2018 2017 Net earnings $ 220,890 $ 181,424 $ 459,546 $ 393,126 Weighted average common shares outstanding 176,284 182,868 177,211 184,034 Dilutive potential common shares: Stock options 1,462 1,465 1,194 1,337 Stock-settled stock units and awards 454 363 406 407 Weighted average common shares and dilutive potential common shares 178,200 184,696 178,811 185,778 Basic net earnings per share $ 1.25 $ 0.99 $ 2.59 $ 2.14 Diluted net earnings per share $ 1.24 $ 0.98 $ 2.57 $ 2.12

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Aug. 31, 2018
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Changes In Accumulated Other Comprehensive Loss By Component	Changes in Accumulated Other Comprehensive Loss By Component Total Net Accumulated Unrecognized Net Other Actuarial Unrecognized Comprehensive (In thousands, net of income taxes) Losses Hedge Gains Loss Balance as of February 28, 2018 $ (68,497 ) $ 14,185 $ (54,312 ) Other comprehensive income before reclassifications — 1,325 1,325 Amounts reclassified from accumulated other comprehensive loss 739 (2,187 ) (1,448 ) Other comprehensive income (loss) 739 (862 ) (123 ) Balance as of August 31, 2018 $ (67,758 ) $ 13,323 $ (54,435 )
Changes In And Reclassifications Out Of Accumulated Other Comprehensive Loss	Changes In and Reclassifications Out of Accumulated Other Comprehensive Loss Three Months Ended August 31 Six Months Ended August 31 (In thousands) 2018 2017 2018 2017 Retirement Benefit Plans: Actuarial loss amortization reclassifications recognized in net pension expense: Cost of sales $ 204 $ 187 $ 405 $ 372 CarMax Auto Finance income 12 11 25 22 Selling, general and administrative expenses 271 255 544 513 Total amortization reclassifications recognized in net pension expense 487 453 974 907 Tax expense (117 ) (178 ) (235 ) (358 ) Amortization reclassifications recognized in net pension expense, net of tax 370 275 739 549 Net change in retirement benefit plan unrecognized actuarial losses, net of tax 370 275 739 549 Cash Flow Hedges (Note 5): Effective portion of changes in fair value 2,187 (3,712 ) 1,800 (7,938 ) Tax (expense) benefit (577 ) 1,461 (475 ) 3,125 Effective portion of changes in fair value, net of tax 1,610 (2,251 ) 1,325 (4,813 ) Reclassifications to CarMax Auto Finance income (1,861 ) 952 (2,970 ) 1,965 Tax benefit (expense) 491 (374 ) 783 (773 ) Reclassification of hedge (gains) losses, net of tax (1,370 ) 578 (2,187 ) 1,192 Net change in cash flow hedge unrecognized gains, net of tax 240 (1,673 ) (862 ) (3,621 ) Total other comprehensive income (loss), net of tax $ 610 $ (1,398 ) $ (123 ) $ (3,072 )

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information Supplemental Cash Flow Information (Tables)	6 Months Ended
	Aug. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Cash Flow, Supplemental Disclosures [Text Block]	Six Months Ended August 31 (In thousands) 2018 2017 Non-cash investing and financing activities: Decrease in accrued capital expenditures $ (5,509 ) $ (2,864 ) Increase in finance and capital lease obligations $ 19,605 $ 10,245

Background (Narrative) (Details

Background (Narrative) (Details) $ in Millions	3 Months Ended	6 Months Ended
	Aug. 31, 2018USD ($)	Aug. 31, 2018segment	Aug. 31, 2017USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Reportable segments | segment		2
Investing Activities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification			$ 29.1
Minimum | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 400
Maximum | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 430

Revenue (Details)

Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 4,766	$ 4,386.6	$ 9,558.6	$ 8,929
Used vehicle sales
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	3,975.4	3,694.2	7,996.4	7,537.6
Wholesale vehicle sales
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	628	547.8	1,245.6	1,101.2
Extended protection plan revenues
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	98.5	85.5	198.6	177.4
Third-party finance fees, net
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(9.7)	(11.6)	(24.2)	(23)
Service revenues
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	36.1	34.5	72.7	68.2
Other
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	37.8	36.3	69.5	67.6
Total other sales and revenues
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 162.7	$ 144.7	$ 316.6	$ 290.2

Revenue (Narrative) (Details)

Revenue (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Aug. 31, 2018	Aug. 31, 2018	Mar. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption			$ 12.9
Receivables, Long-term Contracts or Programs	$ 25.7	$ 25.7
Other Current Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	14.1
Accrued expenses and other current liabilities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	14.1
Other Sales
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 4.4	$ 8.4

CarMax Auto Finance (Components

CarMax Auto Finance (Components Of CarMax Auto Finance Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
Auto Finance Income [Line Items]
Interest and fee income	$ 242,200	$ 213,600	$ 474,500	$ 420,300
Interest expense	(69,100)	(52,200)	(132,900)	(101,200)
Total interest margin	173,100	161,400	341,600	319,100
Provision for loan losses	(40,000)	(32,900)	(70,900)	(61,500)
Total interest margin after provision for loan losses	133,100	128,500	270,700	257,600
Total other expense	(300)	0	(300)	0
Payroll and fringe benefit expense	(9,600)	(8,800)	(19,200)	(17,300)
Other direct expenses	(13,500)	(11,800)	(25,900)	(23,000)
Total direct expenses	(23,100)	(20,600)	(45,100)	(40,300)
CarMax Auto Finance income	109,667	107,936	225,260	217,299
Total average managed receivables	$ 12,067,500	$ 11,112,000	$ 11,921,400	$ 10,970,800
Interest and fee income, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	8.00%	7.70%	8.00%	7.70%
Interest expense, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(2.30%)	(1.90%)	(2.20%)	(1.80%)
Total interest margin, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	5.70%	5.80%	5.70%	5.80%
Provision for loan losses, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(1.30%)	(1.20%)	(1.20%)	(1.10%)
Total interest margin after provision for loan losses, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	4.40%	4.60%	4.50%	4.70%
Total other expense, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	0.00%	0.00%	0.00%	0.00%
Payroll and fringe benefit expense, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(0.30%)	(0.30%)	(0.30%)	(0.30%)
Other direct expenses, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(0.40%)	(0.40%)	(0.40%)	(0.40%)
Total direct expenses, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(0.80%)	(0.70%)	(0.80%)	(0.70%)
CarMax Auto Finance income, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	3.60%	3.90%	3.80%	4.00%

Auto Loan Receivables (Auto Loa

Auto Loan Receivables (Auto Loan Receivables, Net) (Details) - USD ($) $ in Thousands	Aug. 31, 2018	May 31, 2018	Feb. 28, 2018	Aug. 31, 2017	May 31, 2017	Feb. 28, 2017
Non-recourse notes payable	$ 12,252,143		$ 11,644,615
Total ending managed receivables	12,214,100		11,618,900
Accrued interest and fees	51,600		43,200
Other	12,900		2,200
Less allowance for loan losses	(138,100)	$ (134,300)	(128,600)	$ (129,500)	$ (129,800)	$ (123,600)
Auto loan receivables, net	12,140,455		11,535,704
Asset-backed term funding
Total ending managed receivables	9,748,300		9,455,200
Warehouse facilities
Total ending managed receivables	2,106,000		1,834,000
Overcollateralization
Total ending managed receivables	284,500		269,400
Other managed receivables
Total ending managed receivables	$ 75,300		$ 60,300

Auto Loan Receivables (Ending M

Auto Loan Receivables (Ending Managed Receivables By Major Credit Grade) (Details) - USD ($) $ in Millions	Aug. 31, 2018	Feb. 28, 2018
Financing Receivable, By Major Credit Grade [Line Items]
Total ending managed receivables	$ 12,214.1	$ 11,618.9
Total ending managed receivables as percentage by major credit grade	100.00%	100.00%
Credit Grade A
Financing Receivable, By Major Credit Grade [Line Items]
Total ending managed receivables	$ 6,031.2	$ 5,725.1
Total ending managed receivables as percentage by major credit grade	49.40%	49.30%
Credit Grade B
Financing Receivable, By Major Credit Grade [Line Items]
Total ending managed receivables	$ 4,376.9	$ 4,133.8
Total ending managed receivables as percentage by major credit grade	35.80%	35.60%
Credit Grade C And Other
Financing Receivable, By Major Credit Grade [Line Items]
Total ending managed receivables	$ 1,806	$ 1,760
Total ending managed receivables as percentage by major credit grade	14.80%	15.10%

Auto Loan Receivables (Allowanc

Auto Loan Receivables (Allowance For Loan Losses) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017	May 31, 2018	Feb. 28, 2018	May 31, 2017	Feb. 28, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance as of beginning of period	$ 134.3	$ 129.8	$ 128.6	$ 123.6
Charge-offs	(64.9)	(60.4)	(123.8)	(114.5)
Recoveries	28.7	27.2	62.4	58.9
Provision for loan losses	40	32.9	70.9	61.5
Balance as of end of period	$ 138.1	$ 129.5	$ 138.1	$ 129.5
Allowance For Loan Losses, percent
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Item as percent of total ending managed receivables	1.13%	1.15%	1.13%	1.15%	1.13%	1.11%	1.18%	1.16%

Auto Loan Receivables (Past Due

Auto Loan Receivables (Past Due Receivables) (Details) - USD ($) $ in Millions	Aug. 31, 2018	Feb. 28, 2018
Financing Receivable, Past Due [Line Items]
Total ending managed receivables	$ 12,214.1	$ 11,618.9
Total past due	$ 419	$ 393.2
Past due receivables as a percentage of total ending managed receivables	3.40%	3.40%
Total ending managed receivables, percent
Financing Receivable, Past Due [Line Items]
Item as percent of total ending managed receivables	100.00%	100.00%
Thirty One To Sixty Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total past due	$ 262.8	$ 246.6
Past due receivables as a percentage of total ending managed receivables	2.10%	2.10%
Sixty One To Ninety Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total past due	$ 124.4	$ 116.9
Past due receivables as a percentage of total ending managed receivables	1.00%	1.00%
Greater Than Ninety Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total past due	$ 31.8	$ 29.7
Past due receivables as a percentage of total ending managed receivables	0.30%	0.30%

Derivative Instruments And He_2

Derivative Instruments And Hedging Activities (Narrative) (Details) - Designated As Hedging Instrument - Interest Rate Swaps - Cash Flow Hedging - USD ($) $ in Millions	6 Months Ended
	Aug. 31, 2018	Feb. 28, 2018
Derivative [Line Items]
Additional reclassification from AOCL to CAF income within the next 12 months	$ 6.6
Derivative notional amount	$ 2,370	$ 2,160

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule Of Items Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands	Aug. 31, 2018	Feb. 28, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market securities	$ 343,551	$ 276,894
Mutual fund investments	20,552	19,429
Derivative instruments	3,988	12,127
Total assets at fair value	$ 368,091	$ 308,450
Percent of total assets at fair value	100.00%	100.00%
Percent of total assets	2.00%	1.80%
Liabilities: Derivative instruments	$ (1,275)	$ (99)
Total liabilities at fair value	$ (1,275)	$ (99)
Percent of total liabilities	0.00%	0.00%
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market securities	$ 343,551	$ 276,894
Mutual fund investments	20,552	19,429
Derivative instruments	0	0
Total assets at fair value	$ 364,103	$ 296,323
Percent of total assets at fair value	98.90%	96.10%
Percent of total assets	2.00%	1.70%
Liabilities: Derivative instruments	$ 0	$ 0
Total liabilities at fair value	$ 0	$ 0
Percent of total liabilities	0.00%	0.00%
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market securities	$ 0	$ 0
Mutual fund investments	0	0
Derivative instruments	3,988	12,127
Total assets at fair value	$ 3,988	$ 12,127
Percent of total assets at fair value	1.10%	3.90%
Percent of total assets	0.00%	0.10%
Liabilities: Derivative instruments	$ (1,275)	$ (99)
Total liabilities at fair value	$ (1,275)	$ (99)
Percent of total liabilities	0.00%	0.00%

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Measurements (Schedule of Carrying Values and Estimated Fair Values of Debt Instruments) (Details) - USD ($) $ in Thousands	Aug. 31, 2018	Feb. 28, 2018
Fair Value Disclosures [Abstract]
Senior Notes	$ 500,000	$ 500,000
Debt Instrument, Fair Value Disclosure	$ 486,149	$ 492,163

Cancellation Reserves (Narrativ

Cancellation Reserves (Narrative) (Details) - USD ($) $ in Millions	Aug. 31, 2018	Feb. 28, 2018
Cancellation Reserves [Abstract]
Cancellation reserves, current portion	$ 58.3	$ 56

Cancellation Reserves (Schedule

Cancellation Reserves (Schedule Of Cancellation Reserves Accrual) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance as of beginning of period	$ 108.7	$ 109	$ 105.2	$ 108.2
Cancellations	(16.7)	(16.6)	(33.3)	(32.9)
Provision for future cancellations	18.6	17.4	38.7	34.5
Balance as of end of period	$ 110.6	$ 109.8	$ 110.6	$ 109.8

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	Aug. 31, 2018	Feb. 28, 2018
Federal Income Tax Note
Unrecognized tax benefits, gross	$ 30.1	$ 28.7

Debt (Schedule Of Debt) (Detail

Debt (Schedule Of Debt) (Details) - USD ($) $ in Thousands	Aug. 31, 2018	Feb. 28, 2018
Debt Instrument [Line Items]
Finance and Capital Lease Obligations	$ 515,746	$ 500,363
Non-Recourse Debt	12,252,143	11,644,615
Total debt	13,613,185	13,142,605
Less: current portion	(411,712)	(365,554)
Unamortized Debt Issuance Expense	(24,152)	(24,239)
Long-term debt, net	13,177,321	12,752,812
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Debt	45,296	197,627
Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt	300,000	300,000
3.86% senior notes dues 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt	100,000	100,000
4.17% senior notes due 2026 [Member]
Debt Instrument [Line Items]
Long-term Debt	200,000	200,000
4.27% senior notes due 2028 [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 200,000	$ 200,000

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Sep. 28, 2018	Feb. 28, 2018
Debt Instrument [Line Items]
Non-recourse notes payable	$ 12,252,143			$ 11,644,615
Capitalized interest	3,100	$ 3,700
Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	1,200,000
Unused capacity	1,150,000
Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument Face Amount	300,000
Outstanding Balance	300,000
Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument Face Amount	500,000
Outstanding Balance	$ 500,000
Finance and capital lease obligation | Minimum
Debt Instrument [Line Items]
Initial lease terms, in years	15 years
Finance and capital lease obligation | Maximum
Debt Instrument [Line Items]
Initial lease terms, in years	20 years
Asset-backed term funding transactions
Debt Instrument [Line Items]
Non-recourse notes payable	$ 10,150,000
Debt maturity, end	Apr. 15, 2025
Warehouse facilities
Debt Instrument [Line Items]
Non-recourse notes payable	$ 2,110,000
Warehouse Facilities Maximum Borrowing Capacity	3,140,000
Remaining borrowing capacity	1,030,000
Warehouse Facility One
Debt Instrument [Line Items]
Warehouse Facilities Maximum Borrowing Capacity	1,300,000
Warehouse Facility Three
Debt Instrument [Line Items]
Warehouse Facilities Maximum Borrowing Capacity	140,000
Warehouse Facility Two
Debt Instrument [Line Items]
Warehouse Facilities Maximum Borrowing Capacity	$ 1,700,000
Subsequent Event [Member] | Warehouse Facility Three
Debt Instrument [Line Items]
Warehouse Facilities Maximum Borrowing Capacity			$ 150,000

Stock and Stock-Based Incenti_3

Stock and Stock-Based Incentive Plans Stock and Stock-Based Incentive Plans (Narrative) (Details) - Share Repurchase Program - USD ($) $ in Millions	Aug. 31, 2018	Aug. 31, 2017
Stock and Stock-Based Incentive Plans
Stock Repurchase Program, Authorized Amount	$ 750
Available for repurchase, as of end of period	$ 638.3	$ 1,251.8

Stock and Stock-Based Incenti_4

Stock and Stock-Based Incentive Plans Stock and Stock-Based Incentive Plans (Schedule of Common Stock Repurchases) (Details) - Share Repurchase Program - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares repurchased	2,291,700	2,453,100	5,599,300	5,487,800
Average Cost Per Share	$ 74.70	$ 63.78	$ 67.61	$ 61.69
Available for repurchase, as of end of period	$ 638.3	$ 1,251.8	$ 638.3	$ 1,251.8

Stock and Stock-Based Incenti_5

Stock and Stock-Based Incentive Plans Stock And Stock-Based Incentive Plans (Composition of Share-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense, before income taxes	$ 25,615	$ 18,240	$ 55,080	$ 37,380
Cost of sales
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense, before income taxes	1,603	1,076	2,894	1,303
Carmax Auto Finance Income
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense, before income taxes	1,237	848	2,434	1,668
Selling, general and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense, before income taxes	$ 22,775	$ 16,316	$ 49,752	$ 34,409

Stock and Stock-Based Incenti_6

Stock and Stock-Based Incentive Plans Stock and Stock-Based Incentive Plans (Composition of Share-Based Compensation Expense - By Grant Type) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	$ 25,615	$ 18,240	$ 55,080	$ 37,380
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	6,493	5,916	17,608	16,286
Cash-settled restricted stock units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	15,540	9,785	27,894	12,903
Stock-settled market stock units (MSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	2,643	2,543	7,279	6,164
Stock-settled performance stock units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	320	(863)	726	490
Restricted stock awards (RSAs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	(54)	478	433	742
Stock-settled deferred stock units (DSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	294	0	294	0
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	379	381	846	795
Other share-based incentives
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	$ 939	$ (4)	$ 2,299	$ 2,027

Stock and Stock-Based Incenti_7

Stock and Stock-Based Incentive Plans Schedule of Stock-based Compensation Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	6 Months Ended
	Aug. 31, 2018	Feb. 28, 2018
Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	8,172	7,762
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	1,738
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	(1,072)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period	(256)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 18.74
Options Outstanding Weighted Average Grant Date Fair Value	$ 16.51
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 49.8
Stock-settled market stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	514	419
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	204
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	(94)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(15)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 81.99
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 74.25
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 18.2
Other share-based incentives
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	162	271
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	23
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	(93)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(39)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 73.22
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 57.45
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 3
Cash-settled restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	1,676	1,460
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	629
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	(339)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(74)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 63.06
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 58.01

Net Earnings Per Share (Basic A

Net Earnings Per Share (Basic And Dilutive Net Earnings Per Share Reconciliations) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
Schedule of Basic and Dilutive Net Earnings Per Share Reconciliation [Line Items]
Net earnings	$ 220,890	$ 181,424	$ 459,546	$ 393,126
Weighted average common shares outstanding, shares	176,284	182,868	177,211	184,034
Weighted average common shares and dilutive potential common shares, shares	178,200	184,696	178,811	185,778
Basic net earnings per share (in dollars per share)	$ 1.25	$ 0.99	$ 2.59	$ 2.14
Diluted net earnings per share (in dollars per share)	$ 1.24	$ 0.98	$ 2.57	$ 2.12
Stock options
Schedule of Basic and Dilutive Net Earnings Per Share Reconciliation [Line Items]
Dilutive potential common shares, shares	1,462	1,465	1,194	1,337
Stock-settled stock units and awards
Schedule of Basic and Dilutive Net Earnings Per Share Reconciliation [Line Items]
Dilutive potential common shares, shares	454	363	406	407

Net Earnings Per Share (Narrati

Net Earnings Per Share (Narrative) (Details) - shares	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
Earnings Per Share [Abstract]
Anti-dilutive securities not included in calculation of diluted net earnings per share	2,210,917	3,130,285	3,805,873	2,854,557

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
Schedule of Accumulated Other Comprehensive Loss [Line Items]
Beginning balance			$ (54,312)
Other comprehensive income before reclassifications			1,325
Amounts reclassified from accumulated other comprehensive loss			(1,448)
Other comprehensive income (loss), net of taxes	$ 610	$ (1,398)	(123)	$ (3,072)
Ending balance	(54,435)		(54,435)
Net Unrecognized Actuarial Losses
Schedule of Accumulated Other Comprehensive Loss [Line Items]
Beginning balance			(68,497)
Other comprehensive income before reclassifications			0
Amounts reclassified from accumulated other comprehensive loss			739
Other comprehensive income (loss), net of taxes			739
Ending balance	(67,758)		(67,758)
Net Unrecognized Hedge Gains (Losses)
Schedule of Accumulated Other Comprehensive Loss [Line Items]
Beginning balance			14,185
Other comprehensive income before reclassifications			1,325
Amounts reclassified from accumulated other comprehensive loss			(2,187)
Other comprehensive income (loss), net of taxes			(862)
Ending balance	$ 13,323		$ 13,323

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Loss (Changes In and Reclassifications Out of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2018	Aug. 31, 2017
Total amortization reclassifications recognized in net pension expense	$ 487	$ 453	$ 974	$ 907
Tax expense	(117)	(178)	(235)	(358)
Amortization reclassifications recognized in net pension expense, net of tax	370	275	739	549
Net change in retirement benefit plan unrecognized actuarial losses, net of tax	370	275	739	549
Effective portion of changes in fair value	2,187	(3,712)	1,800	(7,938)
Tax (expense) benefit	(577)	1,461	(475)	3,125
Effective portion of changes in fair value, net of tax	1,610	(2,251)	1,325	(4,813)
Reclassifications to CarMax Auto Finance income	(1,861)	952	(2,970)	1,965
Tax benefit (expense)	491	(374)	783	(773)
Reclassification of hedge (gains) losses, net of tax	(1,370)	578	(2,187)	1,192
Net change in cash flow hedge unrecognized losses, net of tax	240	(1,673)	(862)	(3,621)
Other comprehensive income (loss), net of taxes	610	(1,398)	(123)	(3,072)
Cost of sales
Total amortization reclassifications recognized in net pension expense	204	187	405	372
CarMax Auto Finance income
Total amortization reclassifications recognized in net pension expense	12	11	25	22
Selling, general and administrative expenses
Total amortization reclassifications recognized in net pension expense	$ 271	$ 255	$ 544	$ 513

Accumulated Other Comprehensi_5

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

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Aug. 31, 2018	Aug. 31, 2017
Supplemental Cash Flow Elements [Abstract]
Decrease in accrued capital expenditures	$ (5,509)	$ (2,864)
Increase in finance and capital lease obligations	$ 19,605	$ 10,245

Contingent Liabilities (Details

Contingent Liabilities (Details) - USD ($) $ in Millions	Aug. 31, 2018	Feb. 28, 2018
Commitments and Contingencies Disclosure [Abstract]
Liability associated with guarantee	$ 7.3	$ 6.1