Revenues associated with our title operations are recognized as closing services are rendered and title insurance policies are issued, both of which generally occur as each home is closed. Insurance brokerage commissions relate to commissions on homeowner and other insurance policies placed with third party carriers through various agency channels. Our performance obligations for policy renewal commissions are considered satisfied upon issuance of the initial policy, and related contract assets for estimated future renewal commissions are included in other assets and totaled $36.8$39.4 million and $35.1$38.5 million at September 30, 2020March 31, 2021 and December 31, 2019,2020, respectively.

Basic earnings per share is computed by dividing income available to common shareholders (the “Numerator”) by the weighted-average number of common shares outstanding, adjusted for unvested shares (the “Denominator”) for the period. Computing diluted earnings per share is similar to computing basic earnings per share, except that the Denominator is increased to include the dilutive effects of stock options, unvested restricted share units, unvested restricted share units, and other

In accordance with Accounting Standards Codification ("ASC") 260, "Earnings Per Share", the two-class method determines earnings per share for each class of common stock and participating securities according to an earnings allocation formula that adjusts the Numerator for dividends or dividend equivalents and participation rights in undistributed earnings. Unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents are participating securities and, therefore, are included in computing earnings per share pursuant to the two-class method. Our outstanding restricted share units and deferred shares are considered participating securities. The following table presents the earnings per common share (000's omitted, except per share data):

Substantially all of the loans originated by us are sold in the secondary mortgage market within a short period of time after origination, generally within 30 days. At September 30, 2020March 31, 2021 and December 31, 2019,2020, residential mortgage loans available-for-sale had an aggregate fair value of $400.1$495.0 million and $509.0$565.0 million, respectively, and an aggregate outstanding principal balance of $382.9$481.5 million and $494.1$539.1 million, respectively. The net gain (loss) resulting from changes in fair value of these loans totaled $(0.7) million and $0.6 million for the three months ended September 30, 2020 and 2019, respectively, and $(2.1) million and $(0.7) million for the nine months ended September 30, 2020 and 2019, respectively. These changes in fair value were substantially offset by changes in the fair value of corresponding hedging instruments. Net gains from the sale of mortgages were $76.6$77.4 million and $36.3$30.9 million forin the three months ended September 30,March 31, 2021 and 2020, and 2019, respectively, and $173.8 million and $90.6 million for the nine months ended September 30, 2020 and 2019, respectively, and have been included in Financial Services revenues.

We are party to interest rate lock commitments ("IRLCs") with customers resulting from our mortgage origination operations. At September 30, 2020March 31, 2021 and December 31, 2019,2020, we had aggregate IRLCs of $471.6$598.0 million and $255.3$367.2 million, respectively, which were originated at interest rates prevailing at the date of commitment. Since we can terminate a loan commitment if the

We hedge our exposure to interest rate market risk relating to residential mortgage loans available-for-sale and IRLCs using forward contracts on mortgage-backed securities, which are commitments to either purchase or sell a specified financial instrument at a specified future date for a specified price, and whole loan investor commitments, which are obligations of an

investor to buy loans at a specified price within a specified time period. Forward contracts on mortgage-backed securities are the predominant derivative financial instruments we use to minimize market risk during the period from the time we extend an interest rate lock to a loan applicant until the time the loan is sold to an investor. At September 30, 2020March 31, 2021 and December 31, 2019,2020, we had unexpired forward contracts of $671.0$887.0 million and $518.2$686.4 million, respectively, and whole loan investor commitments of $148.0$160.5 million and $200.7$169.6 million, respectively. Changes in the fair value of IRLCs and other derivative financial instruments are recognized in Financial Services revenues, and the fair values are reflected in other assets or other liabilities, as applicable.

There are no credit-risk-related contingent features within our derivative agreements, and counterparty risk is considered minimal. Gains and losses on IRLCs and residential mortgage loans available-for-sale are substantially offset by corresponding gains or losses on forward contracts on mortgage-backed securities and whole loan investor commitments. We are generally not exposed to variability in cash flows of derivative instruments for more than approximately 60 days. The fair values of derivative instruments and their locations in the Condensed Consolidated Balance Sheets are summarized below ($000’s omitted):

We are exposed to credit losses primarily through our vendors and insurance carriers. We assess and monitor each counterparty’s ability to pay amounts owed by considering contractual terms and conditions, the counterparty’s financial condition, macroeconomic factors, and business strategy.

On January 1, 2020, we adopted ASC 326, which changed the impairment model for most financial assets and certain other instruments from an "incurred loss" approach to a new "expected credit loss" methodology. We adopted ASC 326 using the modified retrospective transition method. The amendment requires entities to consider a broader range of information to estimate expected credit losses, which may result in earlier recognition of losses. Our adoption of ASC 326 resulted in a $0.7 million decrease to retained earnings as of January 1, 2020.

In January 2017, the FASB issued ASU No. 2017-04, "Intangibles - Goodwill and Other (Topic 350): Simplifying the Accounting for Goodwill Impairment", which removed the requirement to perform a hypothetical purchase price allocation to measure goodwill impairment. Under the new standard, goodwill impairment is determined by evaluating the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. We adopted the standard for annual and interim periods beginning January 1, 2020, and the standard was followed in the previously mentioned assessment of the ICG goodwill.

We capitalize interest cost into inventory during the active development and construction of our communities. In all periods presented, we capitalized substantially all Homebuilding interest costs into inventory because the level of our active inventory exceeded our debt levels. Information related to interest capitalized into inventory is as follows ($000’s omitted):

We enter into land option agreements in order to procure land for the construction of homes in the future. Pursuant to these land option agreements, we generally provide a deposit to the seller as consideration for the right to purchase land at different times in the future, usually at predetermined prices. Such contracts enable us to defer acquiring portions of properties owned by third parties or unconsolidated entities until we have determined whether and when to exercise our option, which reduces our financial risks associated with long-term land holdings. Option deposits and pre-acquisition costs (such as environmental testing, surveys, engineering, and entitlement costs) are capitalized if the costs are directly identifiable with the land under option, the costs would be capitalized if we owned the land, and acquisition of the property is probable. Such costs are reflected in other assets and are reclassified to inventory upon taking title to the land. We write off deposits and pre-acquisition costs when it becomes probable that we will not go forward with the project or recover the capitalized costs. Such decisions take into consideration changes in local market conditions, the timing of required land purchases, the availability and best use of necessary incremental capital, and other factors. We record any such write-offs of deposits and pre-acquisition costs within other expense, net.

If an entity holding the land under option is a variable interest entity ("VIE"), our deposit represents a variable interest in that entity. No VIEs required consolidation at either September 30, 2020March 31, 2021 or December 31, 20192020 because we determined that we were not the VIEs' primary beneficiary. Our maximum exposure to loss related to these VIEs is generally limited to our deposits and pre-acquisition costs under the land option agreements. The following provides a summary of our interests in land option agreements as of September 30, 2020March 31, 2021 and December 31, 20192020 ($000’s omitted):

We recorded the following land-related charges ($000's omitted):