Legal Matters	9 Months Ended
Aug. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Legal Matters	Legal Matters Nevada Development Contract Litigation On November 4, 2011, the Eighth Judicial District Court, Clark County, Nevada set for trial a consolidated action against KB HOME Nevada Inc., a wholly owned subsidiary of the Company (“KB Nevada”), in a case entitled Las Vegas Development Associates, LLC, Essex Real Estate Partners, LLC, et al. v. KB HOME Nevada Inc. In 2007, Las Vegas Development Associates, LLC (“LVDA”) agreed to purchase from KB Nevada approximately 83 acres of land located near Las Vegas, Nevada. LVDA subsequently assigned its rights to Essex Real Estate Partners, LLC (“Essex”). KB Nevada and Essex entered into a development agreement relating to certain major infrastructure improvements. LVDA’s and Essex’s complaint, initially filed in 2008, alleges that KB Nevada breached the development agreement, and also alleges that KB Nevada fraudulently induced them to enter into the purchase and development agreements. LVDA’s and Essex’s lenders subsequently filed related actions that were consolidated into the LVDA/Essex matter. The consolidated plaintiffs seek rescission of the agreements or a rescissory measure of damages or, in the alternative, compensatory damages of $55 million plus unspecified punitive damages and other damages, and interest charges in excess of $41 million (the “Claimed Damages”). KB Nevada denies the allegations and damages, and believes it has meritorious defenses to the consolidated plaintiffs’ claims. While the ultimate outcome is uncertain — the Company believes it is reasonably possible that the loss in this matter could range from zero to the amount of the Claimed Damages and could be material to the Company’s consolidated financial statements — KB Nevada believes it will be successful in defending against the plaintiffs’ claims and that the plaintiffs will not be awarded rescission or damages. The non-jury trial was set for September 2012, but has been continued until January 2013. Southern California Project Development Case On December 27, 2011, the jury in a case entitled Estancia Coastal, LLC v. KB HOME Coastal Inc. et al. returned a verdict against KB HOME Coastal Inc., a wholly owned subsidiary, and the Company for $9.8 million, excluding legal fees and interest. The case related to a land option contract and a construction agreement between KB HOME Coastal Inc. and the plaintiff. Based on pre-trial analysis, the verdict was not expected, and KB HOME Coastal Inc. and the Company jointly filed a motion for judgment notwithstanding the verdict and a motion for a new trial, which were heard on May 18, 2012. On May 23, 2012, the trial court denied the motions and on June 4, 2012 entered a judgment in favor of the plaintiff in the amount of $9.2 million plus pre-judgment interest of approximately $.9 million. The judgment entered reflects an earlier payment by the Company to the plaintiff of a portion of the jury’s award and does not include legal fees and costs and post-judgment interest. The Company had established an accrual for this matter based on its pre-judgment estimate of the probable loss. However, as a result of the trial court’s decision and probable legal fees and costs award, the Company recorded a charge of $8.8 million in the second quarter of 2012 to increase the accrual for this matter to $11.7 million at August 31, 2012. The charge was included in selling, general and administrative expenses in the Company’s consolidated statement of operations. On September 14, 2012, following a hearing, the trial court awarded legal fees and costs to the plaintiff of approximately $1.4 million. In light of the legal fees and costs awarded on September 14, 2012, the Company continues to believe its accrual at August 31, 2012 reflects the probable outcome of the matter. KB HOME Coastal Inc. and the Company have appealed the entry of judgment. While the ultimate outcome is uncertain, KB HOME Coastal Inc. and the Company believe they will be successful in resolving the matter for an amount less than the judgment. Other Matters In addition to the specific proceedings described above, the Company is involved in other litigation and regulatory proceedings incidental to its business that are in various procedural stages. The Company believes that the accruals it has recorded for probable and reasonably estimable losses with respect to these proceedings are adequate and that, as of August 31, 2012, it was not reasonably possible that an additional material loss had been incurred in an amount in excess of the estimated amounts already recognized on the Company’s consolidated financial statements. The Company evaluates its accruals for litigation and regulatory proceedings at least quarterly and, as appropriate, adjusts them to reflect (i) the facts and circumstances known to the Company at the time, including information regarding negotiations, settlements, rulings and other relevant events and developments; (ii) the advice and analyses of counsel; and (iii) the assumptions and judgment of management. Similar factors and considerations are used in establishing new accruals for proceedings as to which losses have become probable and reasonably estimable at the time an evaluation is made. Based on its experience, the Company believes that the amounts that may be claimed or alleged against it in these proceedings are not a meaningful indicator of its potential liability. The outcome of any of these proceedings, including the defense and other litigation-related costs and expenses the Company may incur, however, is inherently uncertain and could differ significantly from the estimate reflected in a related accrual, if made. Therefore, it is possible that the ultimate outcome of any proceeding, if in excess of a related accrual or if no accrual had been made, could be material to the Company’s consolidated financial statements.

Nevada Development Contract Litigation

On November 4, 2011, the Eighth Judicial District Court, Clark County, Nevada set for trial a consolidated action against KB HOME Nevada Inc., a wholly owned subsidiary of the Company (“KB Nevada”), in a case entitled Las Vegas Development Associates, LLC, Essex Real Estate Partners, LLC, et al. v. KB HOME Nevada Inc. In 2007, Las Vegas Development Associates, LLC (“LVDA”) agreed to purchase from KB Nevada approximately 83 acres of land located near Las Vegas, Nevada. LVDA subsequently assigned its rights to Essex Real Estate Partners, LLC (“Essex”). KB Nevada and Essex entered into a development agreement relating to certain major infrastructure improvements. LVDA’s and Essex’s complaint, initially filed in 2008, alleges that KB Nevada breached the development agreement, and also alleges that KB Nevada fraudulently induced them to enter into the purchase and development agreements. LVDA’s and Essex’s lenders subsequently filed related actions that were consolidated into the LVDA/Essex matter. The consolidated plaintiffs seek rescission of the agreements or a rescissory measure of damages or, in the alternative, compensatory damages of $55 million plus unspecified punitive damages and other damages, and interest charges in excess of $41 million (the “Claimed Damages”). KB Nevada denies the allegations and damages, and believes it has meritorious defenses to the consolidated plaintiffs’ claims. While the ultimate outcome is uncertain — the Company believes it is reasonably possible that the loss in this matter could range from zero to the amount of the Claimed Damages and could be material to the Company’s consolidated financial statements — KB Nevada believes it will be successful in defending against the plaintiffs’ claims and that the plaintiffs will not be awarded rescission or damages. The non-jury trial was set for September 2012, but has been continued until January 2013.

Southern California Project Development Case

On December 27, 2011, the jury in a case entitled Estancia Coastal, LLC v. KB HOME Coastal Inc. et al. returned a verdict against KB HOME Coastal Inc., a wholly owned subsidiary, and the Company for $9.8 million, excluding legal fees and interest. The case related to a land option contract and a construction agreement between KB HOME Coastal Inc. and the plaintiff. Based on pre-trial analysis, the verdict was not expected, and KB HOME Coastal Inc. and the Company jointly filed a motion for judgment notwithstanding the verdict and a motion for a new trial, which were heard on May 18, 2012. On May 23, 2012, the trial court denied the motions and on June 4, 2012 entered a judgment in favor of the plaintiff in the amount of $9.2 million plus pre-judgment interest of approximately $.9 million. The judgment entered reflects an earlier payment by the Company to the plaintiff of a portion of the jury’s award and does not include legal fees and costs and post-judgment interest. The Company had established an accrual for this matter based on its pre-judgment estimate of the probable loss. However, as a result of the trial court’s decision and probable legal fees and costs award, the Company recorded a charge of $8.8 million in the second quarter of 2012 to increase the accrual for this matter to $11.7 million at August 31, 2012. The charge was included in selling, general and administrative expenses in the Company’s consolidated statement of operations. On September 14, 2012, following a hearing, the trial court awarded legal fees and costs to the plaintiff of approximately $1.4 million. In light of the legal fees and costs awarded on September 14, 2012, the Company continues to believe its accrual at August 31, 2012 reflects the probable outcome of the matter. KB HOME Coastal Inc. and the Company have appealed the entry of judgment. While the ultimate outcome is uncertain, KB HOME Coastal Inc. and the Company believe they will be successful in resolving the matter for an amount less than the judgment.

Other Matters

In addition to the specific proceedings described above, the Company is involved in other litigation and regulatory proceedings incidental to its business that are in various procedural stages. The Company believes that the accruals it has recorded for probable and reasonably estimable losses with respect to these proceedings are adequate and that, as of August 31, 2012, it was not reasonably possible that an additional material loss had been incurred in an amount in excess of the estimated amounts already recognized on the Company’s consolidated financial statements. The Company evaluates its accruals for litigation and regulatory proceedings at least quarterly and, as appropriate, adjusts them to reflect (i) the facts and circumstances known to the Company at the time, including information regarding negotiations, settlements, rulings and other relevant events and developments; (ii) the advice and analyses of counsel; and (iii) the assumptions and judgment of management. Similar factors and considerations are used in establishing new accruals for proceedings as to which losses have become probable and reasonably estimable at the time an evaluation is made. Based on its experience, the Company believes that the amounts that may be claimed or alleged against it in these proceedings are not a meaningful indicator of its potential liability. The outcome of any of these proceedings, including the defense and other litigation-related costs and expenses the Company may incur, however, is inherently uncertain and could differ significantly from the estimate reflected in a related accrual, if made. Therefore, it is possible that the ultimate outcome of any proceeding, if in excess of a related accrual or if no accrual had been made, could be material to the Company’s consolidated financial statements.