OutstandingFor the three months ended February 28, 2018, all outstanding stock options, contingently issuable shares associated with outstanding performance-based restricted stock units (each, a “PSU”), and the impact of our 1.375% convertible senior notes due 2019 (“1.375% Convertible Senior Notes due 2019”), were excluded from the diluted loss per share calculation because the effect of their inclusion would be antidilutive. For the three months ended February 28, 2017, outstanding stock options to purchase 2.55.1 million shares of our common stock were excluded from the diluted earnings per share calculations for the three-month and nine-month periods ended August 31, 2017, and outstanding options to purchase 6.6 million shares of our common stock were excluded from the diluted earnings per share calculations for the three-month and nine-month periods ended August 31, 2016calculation because the effect of their inclusion in each case would be antidilutive. Contingently issuable shares associated with outstanding performance-based restricted stock units (each, a “PSU”)PSUs were not included in the basic earnings per share calculations for the periods presented, as the applicable vesting conditions had not been satisfied.

(a)    Land held for sale totaled $56.1$27.8 million at August 31, 2017February 28, 2018 and $63.4$21.8 million at November 30, 2016.2017.

Interest is capitalized to inventories while the related communities or land are being actively developed and until homes are completed or the land is available for immediate sale. Capitalized interest is amortized to construction and land costs as the related inventories are delivered to homebuyers or land buyers (as applicable). Interest and real estate taxes are not capitalized on land held for future development or sale.

Each community or land parcel in our owned inventory is assessed on a quarterly basis to determine if indicators of potential impairment exist. We record an inventory impairment charge on a community or land parcel that is active or held for future development when indicators of potential impairment exist and the carrying value of the real estate asset is greater than the undiscounted future net cash flows the asset is expected to generate. These real estate assets are written down to fair value, which is primarily determined based on the estimated future net cash flows discounted for inherent risk associated with each such asset, or other valuation techniques. We record an inventory impairment charge on land held for sale when the carrying value of a land parcel is greater than its fair value. These real estate assets are written down to fair value, less associated costs to sell. The estimated fair values of such assets are generally based on bona fide letters of intent from outside parties, executed sales contracts, broker quotes or similar information.

We evaluated 4929 and 4339 communities or land parcels for recoverability during the ninethree months ended August 31,February 28, 2018 and 2017, and 2016, respectively. The carrying value of thethose communities or land parcels evaluated during the ninethree months ended August 31,February 28, 2018 and 2017 and 2016 was $436.7$200.1 million and $350.0$366.4 million, respectively. Some of the communities or land parcels evaluated during the nine months ended August 31, 2017 and 2016 were evaluated in more than one quarterly period. Communities or land parcels evaluated for recoverability in more than one quarterly period were counted only once for each nine-month period.

Based on the results of our evaluations, we recognized inventory impairment charges of $7.1$4.7 million for the three months ended August 31, 2017February 28, 2018 and $14.6$3.2 million for the ninethree months ended August 31,February 28, 2017. For the three months and nine months ended August 31, 2016, we recognized inventory impairment charges of $2.6 million and $13.9 million, respectively. The inventory impairment charges for the three months ended February 28, 2018 and nine months ended August 31, 2017 and 2016 reflected our decisions to make changes in our operational strategies aimed at more quickly monetizing our investment in thosecertain communities or land parcels. The inventory impairment charges for the three months and nine months ended August 31, 2017 included one community in California where we decided to accelerate the overall pace for selling and delivering homes, primarily through lowering selling prices. In addition, the inventory impairment charges for these three-month and nine-month periods included two communities and six communities, respectively, where we decided to accelerateby accelerating the overall pace for selling, building and delivering homes on land previously held for future development. The inventory impairment charges for the three months and nine months ended August 31, 2016 included two communities in California where we decided to accelerate the overall pace for selling, building and delivering homes, primarily through lowering selling prices. The inventory impairment charges for the nine months ended August 31, 2016 also included $5.4 million associated with the sales of two land parcels in the Metro Washington, D.C. market as part of the wind down of our operations in that market, and $5.2 million associated with one community in California and one in Florida where we decided to accelerate the overall timing for selling, building and delivering homes on land that was previously held for future development. The charges for the nine months ended August 31, 2016 also reflected the sales of our last remaining land parcels in the Rio Grande Valley area of Texas, which closed in the 2016 second quarter.

The following table summarizes ranges for significant quantitative unobservable inputs we utilized in our fair value measurements with respect to the impaired communities written down to fair value during the periods presented:

As of August 31,February 28, 2018, the aggregate carrying value of our inventory that had been impacted by inventory impairment charges was $178.4 million, representing 20 communities and various other land parcels. As of November 30, 2017, the aggregate carrying value of our inventory that had been impacted by inventory impairment charges was $209.1$177.8 million, representing 26 communities and various other land parcels. As of November 30, 2016, the aggregate carrying value of our inventory that had been impacted by inventory impairment charges was $215.3 million, representing 2824 communities and various other land parcels.

Due to the judgment and assumptions applied in our inventory impairment and land option contract abandonment assessment processes, particularly as to land held for future development, or sale, it is possible that actual results could differ substantially from those estimated.

We have investments in unconsolidated joint ventures that conduct land acquisition, land development and/or other homebuilding activities in various markets where our homebuilding operations are located. We and our unconsolidated joint venture partners make initial and/or ongoing capital contributions to these unconsolidated joint ventures, typically on a pro rata basis, according to our respective equity interests. The obligations to make capital contributions are governed by each such unconsolidated joint venture’s respective operating agreement and related governing documents.

We typically have obtained rights to acquire portions of the land held by the unconsolidated joint ventures in which we currently participate. When an unconsolidated joint venture sells land to our homebuilding operations, we defer recognition of our share of such unconsolidated joint venture’s earnings (losses) until a home sale is closed and title passes to a homebuyer, at which time we account for those earnings (losses) as a reduction (increase) to the cost of purchasing the land from the unconsolidated joint venture. We defer recognition of our share of such unconsolidated joint venture losses only to the extent profits are to be generated from the sale of the home to a homebuyer.

We share in the earnings (losses) of these unconsolidated joint ventures generally in accordance with our respective equity interests. In some instances, we recognize earnings (losses) related to our investment in an unconsolidated joint venture that differ from our equity interest in the unconsolidated joint venture. This typically arises from our deferral of the unconsolidated joint venture’s earnings (losses) from land sales to us, or other items.

The following table presents combined condensed information from the statements of operations of our unconsolidated joint ventures (in thousands):

The following table presents combined condensed balance sheet information for our unconsolidated joint ventures (in thousands):

The following table presents additional information relating to our investments in unconsolidated joint ventures (dollars in thousands):

We and our partners in the unconsolidated joint ventures that have the above-noted construction loan agreements provide certain guarantees and indemnities to the applicable lender, including a guaranty to complete the construction of improvements for the applicable project; a guaranty against losses the lender suffers due to certain bad acts or failures to act by the unconsolidated joint venture or its partners; an indemnity of the lender from environmental issues; and in one case, a guaranty of interest payments on the outstanding balance of the secured debt under the construction loan agreement. In each instance, our actual responsibility under the foregoing guaranty and indemnity obligations is limited to our pro rata interest in the unconsolidated joint venture. We do not have a guaranty or any other obligation to repay or to support the value of the collateral underlying the outstanding secured debt of these unconsolidated joint ventures. However, various financial and

non-financial covenants apply with respect to the outstanding secured debt and the related guaranty and indemnity obligations, and a failure to comply with such covenants could result in a default and cause an applicable lender to seek to enforce such guaranty and indemnity obligations, if and as may be applicable. As of August 31, 2017,February 28, 2018, we were in compliance with the applicable terms of our relevant covenants with respect to the construction loan agreements. We do not believe that our existing exposure under our guaranty and indemnity obligations related to the outstanding secured debt of these unconsolidated joint ventures is material to our consolidated financial statements.

Of the unconsolidated joint venture lots controlled under land option and other similar contracts at August 31, 2017,February 28, 2018, we are committed to purchase 9067 lots from one of our unconsolidated joint ventures in quarterly takedowns over the next three years for an aggregate purchase price of approximately $39.9$30.0 million under agreements that we entered into with the unconsolidated joint venture in 2016.

Our deferred tax assets of $707.7$543.5 million as of August 31, 2017February 28, 2018, after the above-described accounting re-measurement, and $763.8$657.2 million as of November 30, 20162017 were partly offset by valuation allowances of $24.6$26.9 million and $24.8$23.6 million, respectively. As part of our analysis of the TCJA’s income tax effects described above, we increased our deferred tax asset valuation allowance by $3.3 million during the three months ended February 28, 2018. The deferred tax asset valuation allowances as of August 31, 2017February 28, 2018 and November 30, 20162017 were primarily related to certain state net operating losses (“NOLs”) that had not met the “more likely than not” realization standard at those dates. In the three months ended August 31, 2017, we reversed $.2 million of our deferred tax asset valuation allowance due to the utilization of additional state NOLs recognized with the filing of our 2016 state tax returns. Based on our evaluation of our deferred tax assets as of August 31, 2017,February 28, 2018, we determined that most of our deferred tax assets would be realized. Therefore, other than the $3.3 million discussed above, no other adjustments to our deferred tax valuation allowance were needed for the ninethree months ended August 31, 2017.

We will continue to evaluate both the positive and negative evidence on a quarterly basis in determining the need for a valuation allowance with respect to our deferred tax assets. The accounting for deferred tax assets is based upon estimates of future results. Changes in positive and negative evidence, including differences between estimated and actual results, could result in changes in the valuation of our deferred tax assets that could have a material impact on our consolidated financial statements. Changes in existing federal and state tax laws and corporate income tax rates could also affect our actual tax expense,results and the realization of our deferred tax assets over time and/or the value of our deferred tax assets on our consolidated balance sheets.time.

The indenture governing theour senior notes does not contain any financial covenants. Subject to specified exceptions, the indenture contains certain restrictive covenants that, among other things, limit our ability to incur secured indebtedness, or engage in sale-leaseback transactions involving property or assets above a certain specified value. In addition, theour senior notes, (withwith the exception of theour 7 1/4% senior notes due 2018)2018 (“7 1/4% Senior Notes due 2018”), contain certain limitations related to mergers, consolidations, and sales of assets.

Principal payments on senior notes, mortgages and land contracts due to land sellers and other loans are due as follows: 2017 – $179.0 million; 2018 – $310.1$300.0 million; 2019 – $630.0$673.5 million; 2020 – $350.0 million; 2021 – $0; 2022 – $800.0 million; and thereafter – $1.05 billion.$250.0 million.

Fair value measurements of assets and liabilities are categorized based on the following hierarchy:

Fair value measurements are used for inventories on a nonrecurring basis when events and circumstances indicate that their carrying value is not recoverable. The following table presents the fair value hierarchy, pre-impairment value, inventory impairment charges and fair value for our assets measured at fair value on a nonrecurring basis for the ninethree months ended August 31, 2017February 28, 2018 and the year ended November 30, 20162017 (in thousands): 

The following table presents the fair value hierarchy, carrying values and estimated fair values of our financial instruments, except those for which the carrying values approximate fair values (in thousands):

The fair values of our senior notes and convertible senior notes are generally estimated based on quoted market prices for these instruments. The carrying values reported for cash and cash equivalents, and mortgages and land contracts due to land sellers and other loans approximate fair values. The carrying value of corporate-owned life insurance is based on the cash surrender value of the policies and, accordingly, approximates fair value.

Commitments and contingencies include typical obligations of homebuilders for the completion of contracts and those incurred in the ordinary course of business.

We estimate the costs that may be incurred under each limited warranty and record a liability in the amount of such costs at the time the revenue associated with the sale of each home is recognized. Our primary assumption in estimating the amounts we accrue for warranty costs is that historical claims experience is a strong indicator of future claims experience. Factors that affect our warranty liability include the number of homes delivered, historical and anticipated rates of warranty claims,

The changes in our warranty liability were as follows (in thousands):

We self-insure a portion of our overall risk through the use of a captive insurance subsidiary, which provides coverage for our exposure to construction defect, bodily injury and property damage claims and related litigation or regulatory actions, up to certain limits. Our self-insurance liability generally covers our costs of settlements and/or repairs, if any, as well as our costs to defend and resolve the following types of claims:

Our self-insurance liability at each reporting date represents the estimated costs of reported claims, claims incurred but not yet reported, and claim adjustment expenses. The amount of our self-insurance liability is based on an analysis performed by a third-party actuary that uses our historical claim and expense data, as well as industry data to estimate these overall costs. Key assumptions used in developing these estimates include claim frequencies, severities and resolution patterns, which can occur over an extended period of time. These estimates are subject to variability due to the length of time between the delivery of a home to a homebuyer and when a construction defect claim is made, and the ultimate resolution of such claim; uncertainties regarding such claims relative to our markets and the types of product we build; and legal or regulatory actions and/or

Our self-insurance liability is presented on a gross basis without consideration of insurance recoveries and amounts we have paid on behalf of and expect to recover from other parties, if any. Estimated probable self-insuranceinsurance and other recoveries of $75.0$71.2 million and $84.5$71.3 million are included in receivables in our consolidated balance sheets at August 31, 2017February 28, 2018 and November 30, 2016,2017, respectively. These self-insurance recoveries are principally based on actuarially determined amounts and depend on various factors, including, among other things, the above-described claim cost estimates, our insurance policy coverage limits for the applicable policy year(s), historical third-party recovery rates, insurance industry practices, the regulatory environment, and legal precedent, and are subject to a high degree of variability from period to period. Because of the inherent uncertainty and variability in these assumptions, our actual insurance recoveries could differ significantly from amounts currently estimated.