Stockholders' Equity	12 Months Ended
Stockholders' Equity	Nov. 30, 2019
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Preferred Stock. To help protect the benefits of our NOLs and other deferred tax assets from an ownership change under Section 382, on January 22, 2009, we adopted a Rights Agreement (“Prior Rights Agreement”), and we declared a dividend distribution of one preferred share purchase right for each outstanding share of common stock that was payable to stockholders of record as of the close of business on March 5, 2009. On April 12, 2018, we entered into an Amended and Restated Rights Agreement with Computershare Inc., as rights agent, (“2018 Rights Agreement”) following its approval by our stockholders at our 2018 Annual Meeting held on April 12, 2018. The 2018 Rights Agreement amended and restated the Prior Rights Agreement and extended the latest possible expiration date of the rights issued pursuant to the Prior Rights Agreement to the close of business on April 30, 2021, and made certain other related changes. Otherwise, the 2018 Rights Agreement’s terms are substantively the same as those of the Prior Rights Agreement. Subject to the terms, provisions and conditions of the 2018 Rights Agreement, if these rights become exercisable, each right would initially represent the right to purchase from us 1/100th of a share of our Series A Participating Cumulative Preferred Stock for a purchase price of $85.00 (“Purchase Price”). If issued, each fractional share of preferred stock would generally give a stockholder approximately the same dividend, voting and liquidation rights as does one share of our common stock. However, prior to exercise, a right does not give its holder any rights as a stockholder, including without limitation any dividend, voting or liquidation rights. The rights will not be exercisable until the earlier of (a) 10 calendar days after a public announcement by us that a person or group has become an Acquiring Person (as defined under the Prior Rights Agreement) and (b) 10 business days after the commencement of a tender or exchange offer by a person or group if upon consummation of the offer the person or group would beneficially own 4.9% or more of our outstanding common stock. Until these rights become exercisable (“Distribution Date”), common stock certificates and/or book-entry shares will evidence the rights and may contain a notation to that effect. Any transfer of shares of our common stock prior to the Distribution Date will constitute a transfer of the associated rights. After the Distribution Date, the rights may be transferred other than in connection with the transfer of the underlying shares of our common stock. If there is an Acquiring Person on the Distribution Date or a person or group becomes an Acquiring Person after the Distribution Date, each holder of a right, other than rights that are or were beneficially owned by an Acquiring Person, which will be void, will thereafter have the right to receive upon exercise of a right and payment of the Purchase Price, that number of shares of our common stock having a market value of two times the Purchase Price. After the later of the Distribution Date and the time we publicly announce that an Acquiring Person has become such, our board of directors may exchange the rights, other than rights that are or were beneficially owned by an Acquiring Person, which will be void, in whole or in part, at an exchange ratio of one share of common stock per right, subject to adjustment. At any time prior to the later of the Distribution Date and the time we publicly announce that an Acquiring Person becomes such, our board of directors may redeem all of the then-outstanding rights in whole, but not in part, at a price of $.001 per right, subject to adjustment (“Redemption Price”). The redemption will be effective immediately upon the board of directors’ action, unless the action provides that such redemption will be effective at a subsequent time or upon the occurrence or nonoccurrence of one or more specified events, in which case the redemption will be effective in accordance with the provisions of the action. Immediately upon the effectiveness of the redemption of the rights, the right to exercise the rights will terminate and the only right of the holders of rights will be to receive the Redemption Price, with interest thereon. The rights issued pursuant to the 2018 Rights Agreement will expire on the earliest of (a) the close of business on April 30, 2021 (b) the time at which the rights are redeemed, (c) the time at which the rights are exchanged, (d) the time at which our board of directors determines that a related provision in our Restated Certificate of Incorporation is no longer necessary, and (e) the close of business on the first day of a taxable year of ours to which our board of directors determines that no tax benefits may be carried forward. Common Stock. On May 14, 2018, our board of directors authorized us to repurchase a total of up to 4,000,000 shares of our outstanding common stock. This authorization reaffirmed and incorporated the then-current balance of 1,627,000 shares that remained under a prior board-approved share repurchase program. In 2018, we repurchased 1,806,053 shares of our common stock pursuant to this authorization, at a total cost of $35.0 million. The amount and timing of shares remaining to be purchased under the the remaining share repurchase authorization are subject to market and business conditions and other factors, and purchases may be made from time to time and at any time through open market or privately negotiated transactions. The remaining share repurchase authorization will continue in effect until fully used or earlier terminated or suspended by the board of directors. Unrelated to the share repurchase program, our board of directors authorized the repurchase of not more than 680,000 shares of our outstanding common stock, and also authorized potential future grants of up to 680,000 stock payment awards under the KB Home 2014 Equity Incentive Plan (“2014 Plan”), in each case solely as necessary for director elections in respect of outstanding Director Plan SARs. The 2014 Plan, which was amended in April 2016, is discussed in Note 20 – Employee Benefit and Stock Plans. As of November 30, 2019, we have not repurchased any shares and no stock payment awards have been granted under the 2014 Plan, as amended, pursuant to the respective board of directors’ authorizations. Our board of directors declared quarterly cash dividends of $.025 per share of common stock in the 2019 first and second quarters. In the 2019 third quarter, our board of directors approved an increase in the quarterly cash dividend on our common stock to $.090 per share, and declared quarterly cash dividends at the new higher rate in the 2019 third and fourth quarters. Our board of directors declared four quarterly cash dividends of $.025 per share of common stock in 2018 and 2017. All dividends declared during 2019, 2018 and 2017 were also paid during those years. Treasury Stock. In addition to the shares purchased in 2018 pursuant to our share repurchase program, we acquired $7.3 million, $8.5 million and $6.7 million of our common stock in 2019, 2018 and 2017, respectively. All of the common stock acquired in 2019 and 2017 and a portion of the common stock acquired in 2018 consisted of previously issued shares delivered to us by employees to satisfy their withholding tax obligations on the vesting of PSUs and restricted stock awards or of forfeitures of previous restricted stock awards. Treasury stock is recorded at cost. Differences between the cost of treasury stock and the reissuance proceeds are recorded to paid-in capital. These transactions are not considered repurchases under the 4,000,000 share repurchase program described above.