Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2022
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.
Investments	Investments Our fixed maturity and short-term investments are classified as available for sale as we may sell securities from time to time to provide liquidity and in response to changes in the market. Debt securities classified as available for sale are reported at fair value with unrealized gains and losses on these securities reported in other comprehensive income, net of deferred income taxes. See Note 15 for a description of the valuation methods for investments available for sale. We monitor our fixed maturities for unrealized losses that appear to be other-than-temporary. A fixed maturity security is considered to be other-than-temporarily impaired when the security's fair value is less than its amortized cost basis and 1) we intend to sell the security, 2) it is more likely than not that we will be required to sell the security before recovery of the security's amortized cost basis, or 3) we believe we will be unable to recover the entire amortized cost basis of the security (i.e., a credit loss has occurred). When we determine that a credit loss has been incurred, but we do not intend to sell the security and it is not more likely than not that we will be required to sell the security before recovery of the security's amortized cost basis, the portion of the other-than-temporary impairment that is credit related is recorded as a realized loss in the consolidated statements of comprehensive income, and the portion of the other-than-temporary impairment that is not credit related is included in other comprehensive income. For those fixed maturities for which an other-than-temporary impairment has occurred, we adjust the amortized cost basis of the security and record a realized loss in the consolidated statements of comprehensive income. We recognize purchase premiums and discounts in interest income using the interest method over the securities' estimated holding periods, until maturity, or call date, if applicable. Gains and losses on the sales of securities are recorded on the trade date and are determined using the specific identification method. Short-term investments are defined as short-term, highly liquid investments, both readily convertible to cash and having maturities at acquisition of twelve months or less.
Investments, Other Invested Assets	Other invested assets are principally comprised of limited partnership interests which are generally accounted for under the equity method of accounting or fair value using net asset value (or its equivalent) as a practical expedient, with changes in value reported in income from other invested assets. In applying the equity method or fair value using net asset value (or its equivalent) as a practical expedient, these investments are initially recorded at cost and are subsequently adjusted based on the Company’s proportionate share of the net income or loss of the partnership or changes in fair value. We have elected to classify distributions received from these investments using the cumulative earnings approach. Due to the timing of receiving financial information from these partnerships, the results are generally reported on a one month or quarter lag.
Long-Lived Assets	Long-Lived AssetsProperty and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets. Repairs and maintenance are charged to expense as incurred. Estimated useful lives are 5 years for furniture and fixtures and 2 to 3 years for equipment, computer hardware and purchased software. Certain costs associated with the acquisition or development of internal-use software are capitalized. Once the software is ready for its intended use, these costs are amortized on a straight-line basis over the software's expected useful life, which is generally 3 years. We amortize leasehold improvements over the shorter of the lives of the leases or estimated service lives of the leasehold improvements.
Deferred Policy Acquisition Costs	Deferred Policy Acquisition CostsWe defer certain personnel costs and premium tax expense directly related to the successful acquisition of new insurance policies and amortize these costs over the period the related estimated gross profits are recognized in order to match costs and revenues. We do not defer any underwriting costs associated with our contract underwriting services. Costs related to the acquisition of mortgage insurance business are initially deferred and reported as deferred policy acquisition costs. Consistent with industry accounting practice, amortization of these costs for each underwriting year book of business is recognized in proportion to estimated gross profits. Estimated gross profits are composed of earned premium, interest income, losses and loss adjustment expenses. The deferred costs are adjusted as appropriate for policy cancellations to be consistent with our revenue recognition policy. We estimate the rate of amortization to reflect actual experience and any changes to persistency or loss development. Deferred policy acquisition costs are reviewed periodically to determine that they do not exceed recoverable amounts, after considering investment income.
Insurance Premium Revenue Recognition	Insurance Premium Revenue Recognition Mortgage guaranty insurance policies are contracts that are generally non-cancelable by the insurer, are renewable at a fixed price, and provide for payment of premium on a monthly, annual or single basis. Upon renewal, we are not able to re-underwrite or re-price our policies. Consistent with industry accounting practices, premiums written on a monthly basis are earned as coverage is provided. Monthly policies accounted for 94% of earned premium in 2022. Premiums written on an annual basis are amortized on a pro rata basis over the year of coverage. Primary mortgage insurance written on policies covering more than one year are referred to as single premium policies. A portion of the revenue from single premium policies is recognized in earned premium in the current period, and the remaining portion is deferred as unearned premium and earned over the expected life of the policy. If single premium policies related to insured loans are cancelled due to repayment by the borrower, and the premium is non-refundable, then the remaining unearned premium related to each cancelled policy is recognized as earned premium upon notification of the cancellation. The Company recorded $20.8 million and $63.8 million of earned premium related to policy cancellations for the years ended December 31, 2022 and 2021, respectively. Unearned premium represents the portion of premium written that is applicable to the estimated unexpired risk of insured loans. Rates used to determine the earning of single premium policies are estimates based on an analysis of the expiration of risk.
Reserve for Losses and Loss Adjustment Expenses	Reserve for Losses and Loss Adjustment Expenses We establish reserves for losses based on our best estimate of ultimate claim costs for defaulted loans using the general principles contained in ASC No. 944, in accordance with industry practice. However, consistent with industry standards for mortgage insurers, we do not establish loss reserves for future claims on insured loans which are not currently in default. Loans are classified as in default when the borrower has missed two consecutive payments. Once we are notified that a borrower has defaulted, we will consider internal and third-party information and models, including the status of the loan as reported by its servicer and the type of loan product to determine the likelihood that a default will reach claim status. In addition, we will project the amount that we will pay if a default becomes a claim (referred to as "claim severity"). Based on this information, at each reporting date we determine our best estimate of loss reserves at a given point in time. Included in loss reserves are reserves for incurred but not reported ("IBNR") claims. IBNR reserves represent our estimated unpaid losses on loans that are in default, but have not yet been reported to us as delinquent by our customers. We will also establish reserves for associated loss adjustment expenses, consisting of the estimated cost of the claims administration process, including legal and other fees and expenses associated with administering the claims process. Establishing reserves is inherently subjective as it requires estimates that are susceptible to significant revision as more information becomes available. Our estimates of claim rates and claim sizes will be strongly influenced by prevailing economic conditions, such as the overall state of the economy, current rates or trends in unemployment, changes in housing values and/or interest rates, and our best judgments as to the future values or trends of these macroeconomic factors. Losses incurred are also generally affected by the characteristics of our insured loans, such as the loan amount, loan-to-value ratio, the percentage of coverage on the insured loan and the credit quality of the borrower.
Premium Deficiency Reserve	Premium Deficiency ReserveWe are required to establish a premium deficiency reserve if the net present value of the expected future losses and expenses for a particular group of policies exceeds the net present value of expected future premium, anticipated investment income and existing reserves for that specified group of policies. We reassess our expectations for premium, losses and expenses of our mortgage insurance business periodically and update our premium deficiency analysis accordingly.
Derivative Instruments	Derivative Instruments Derivative instruments, including embedded derivative instruments, are recognized at fair value in the consolidated balance sheets. The amount of monthly reinsurance premiums ceded under our reinsurance contracts will fluctuate due to changes in one-month LIBOR or SOFR and changes in money market rates. As the reinsurance premium will vary based on changes in these rates, we concluded that these reinsurance agreements contain embedded derivatives that are accounted for separately like freestanding derivatives.
Stock-Based Compensation	Stock-Based Compensation We measure the cost of employee services received in exchange for awards of equity instruments at the grant date of the award using a fair value based method. Fair value is determined on the date of grant based on quoted market prices. We recognize compensation expense on nonvested shares over the vesting period of the award. Excess tax benefits and tax deficiencies associated with share-based payments are recognized as income tax expense or benefit in the income statement and treated as discrete items in the reporting period.
Income Taxes	Income Taxes Deferred income tax assets and liabilities are determined using the asset and liability (balance sheet) method. Under this method, we determine the net deferred tax asset or liability based on the tax effects of the temporary differences between the book and tax bases of the various assets and liabilities and give current recognition to changes in tax rates and laws. Changes in tax laws, rates, regulations and policies, or the final determination of tax audits or examinations, could materially affect our tax estimates. We evaluate the realizability of the deferred tax asset and recognize a valuation allowance if, based on the weight of all available positive and negative evidence, it is more likely than not that some portion or all of the deferred tax asset will not be realized. When evaluating the realizability of the deferred tax asset, we consider estimates of expected future taxable income, existing and projected book/tax differences, carryback and carryforward periods, tax planning strategies available, and the general and industry specific economic outlook. This realizability analysis is inherently subjective, as it requires management to forecast changes in the mortgage market, as well as the related impact on mortgage insurance, and the competitive and general economic environment in future periods. Changes in the estimate of deferred tax asset realizability, if applicable, are included in income tax expense on the consolidated statements of comprehensive income. ASC No. 740 provides a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. In accordance with ASC No. 740, before a tax benefit can be recognized, a tax position is evaluated using a threshold that it is more likely than not that the tax position will be sustained upon examination. When evaluating the more-likely-than-not recognition threshold, ASC No. 740 provides that a company should presume the tax position will be examined by the appropriate taxing authority that has full knowledge of all relevant information. If the tax position meets the more-likely-than-not recognition threshold, it is initially and subsequently measured as the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. As described in Note 12, we purchase non-interest-bearing United States Mortgage Guaranty Tax and Loss Bonds ("T&L Bonds") issued by the Treasury Department. These assets are carried at cost and are reported as prepaid federal income tax on the consolidated balance sheets. It is our policy to classify interest and penalties as income tax expense and to use the aggregate portfolio approach to release income tax effects from accumulated other comprehensive income.
Earnings per Share	Earnings per Share Basic earnings per common share amounts are calculated based on income available to common stockholders and the weighted average number of common shares outstanding during the reporting period. Diluted earnings per common share amounts are calculated based on income available to common stockholders and the weighted average number of common and potential common shares outstanding during the reporting period. Potential common shares, composed of the incremental common shares issuable upon vesting of unvested common shares and common share units, are included in the earnings per share calculation to the extent that they are dilutive.
Recently Issued Accounting Standards	Recently Issued Accounting Standards Accounting Standards Not Yet Adopted In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. The amendments in this update provide temporary optional guidance to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform. It provides optional expedients and exceptions for applying generally accepted accounting principles to contract, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. This standard may be elected and applied prospectively over time from March 12, 2020 through December 31, 2024, as amended by ASU 2022-06, as reference rate reform activities occur. The adoption of, and future elections under, this ASU are not expected to have a material impact on our consolidated financial statements as the ASU will ease, if warranted, the requirements for accounting for the future effects of the rate reform. We continue to monitor the impact the discontinuance of LIBOR or another reference rate will have on our contracts and other transactions. In June 2022, the FASB issued ASU No. 2022-03, Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions. This update clarifies the guidance in ASC 820 on the fair value measurement of an equity security that is subject to a contractual sale restriction and requires specific disclosures related to such an equity security. The update clarifies that a contractual sale restriction prohibiting the sale of an equity security is a characteristic of the reporting entity holding the equity security and is not included in the equity security's unit of account. Accordingly, an entity should not consider the contractual sale restriction when measuring the equity security’s fair value. The update also requires specific disclosures related to equity securities that are subject to contractual sale restrictions, including (1) the fair value of such equity securities reflected in the balance sheet, (2) the nature and remaining duration of the corresponding restrictions, and (3) any circumstances that could cause a lapse in the restrictions. The ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within those fiscal years, with early adoption permitted. The adoption of this ASU is not expected to have a material effect on the Company's consolidated operating results or financial position.
Fair Value of Financial Instruments	Fair Value of Financial InstrumentsWe carry certain of our financial instruments at fair value. We define fair value as the current amount that would be exchanged to sell an asset or transfer a liability, other than in a forced liquidation. Fair Value Hierarchy ASC No. 820 specifies a hierarchy of valuation techniques based on whether the inputs to those valuation techniques are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect our market assumptions. The level within the fair value hierarchy to measure the financial instrument shall be determined based on the lowest level input that is significant to the fair value measurement. The three levels of the fair value hierarchy are as follows: •Level 1—Quoted prices for identical instruments in active markets accessible at the measurement date. •Level 2—Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and valuations in which all significant inputs are observable in active markets. Inputs are observable for substantially the full term of the financial instrument. •Level 3—Valuations derived from one or more significant inputs that are unobservable. Determination of Fair Value When available, we generally use quoted market prices to determine fair value and classify the financial instrument in Level 1. In cases where quoted market prices for similar financial instruments are available, we utilize these inputs for valuation techniques and classify the financial instrument in Level 2. In cases where quoted market prices are not available, fair values are based on estimates using discounted cash flows, present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rates and estimates of future cash flows and we classify the financial instrument in Level 3. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument. We used the following methods and assumptions in estimating fair values of financial instruments: •Investments available for sale—Investments available for sale are valued using quoted market prices in active markets, when available, and those investments are classified as Level 1 of the fair value hierarchy. Level 1 investments available for sale include investments such as U.S. Treasury securities and money market funds. Investments available for sale are classified as Level 2 of the fair value hierarchy if quoted market prices are not available and fair values are estimated using quoted prices of similar securities or recently executed transactions for the securities. U.S. agency securities, U.S. agency mortgage-backed securities, municipal debt securities, non-U.S. government securities, corporate debt securities, residential and commercial mortgage securities and asset-backed securities are classified as Level 2 investments. We use independent pricing sources to determine the fair value of securities available for sale in Level 1 and Level 2 of the fair value hierarchy. We use one primary pricing service to provide individual security pricing based on observable market data and receive one quote per security. To ensure securities are appropriately classified in the fair value hierarchy, we review the pricing techniques and methodologies of the independent pricing service and believe that their policies adequately consider market activity, either based on specific transactions for the issue valued or based on modeling of securities with similar credit quality, duration, yield and structure that were recently traded. U.S. agency securities, U.S. agency mortgage-backed securities, municipal debt securities, non-U.S. government securities, and corporate debt securities are valued by our primary vendor using recently executed transactions and proprietary models based on observable inputs, such as interest rate spreads, yield curves and credit risk. Residential and commercial mortgage securities and asset-backed securities are valued by our primary vendor using proprietary models based on observable inputs, such as interest rate spreads, prepayment speeds and credit risk. As part of our evaluation of investment prices provided by our primary pricing service, we obtained and reviewed their pricing methodologies which include a description of how each security type is evaluated and priced. We review the reasonableness of prices received from our primary pricing service by comparison to prices obtained from additional pricing sources. We have not made any adjustments to the prices obtained from our primary pricing service.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2022

The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates.

Investments

Our fixed maturity and short-term investments are classified as available for sale as we may sell securities from time to time to provide liquidity and in response to changes in the market. Debt securities classified as available for sale are reported at fair value with unrealized gains and losses on these securities reported in other comprehensive income, net of deferred income taxes. See Note 15 for a description of the valuation methods for investments available for sale.

We monitor our fixed maturities for unrealized losses that appear to be other-than-temporary. A fixed maturity security is considered to be other-than-temporarily impaired when the security's fair value is less than its amortized cost basis and 1) we intend to sell the security, 2) it is more likely than not that we will be required to sell the security before recovery of the security's amortized cost basis, or 3) we believe we will be unable to recover the entire amortized cost basis of the security (i.e., a credit loss has occurred). When we determine that a credit loss has been incurred, but we do not intend to sell the security and it is not more likely than not that we will be required to sell the security before recovery of the security's amortized cost basis, the portion of the other-than-temporary impairment that is credit related is recorded as a realized loss in the consolidated statements of comprehensive income, and the portion of the other-than-temporary impairment that is not credit related is included in other comprehensive income. For those fixed maturities for which an other-than-temporary impairment has occurred, we adjust the amortized cost basis of the security and record a realized loss in the consolidated statements of comprehensive income.

We recognize purchase premiums and discounts in interest income using the interest method over the securities' estimated holding periods, until maturity, or call date, if applicable. Gains and losses on the sales of securities are recorded on the trade date and are determined using the specific identification method.

Short-term investments are defined as short-term, highly liquid investments, both readily convertible to cash and having maturities at acquisition of twelve months or less.

Investments, Other Invested Assets

Other invested assets are principally comprised of limited partnership interests which are generally accounted for under the equity method of accounting or fair value using net asset value (or its equivalent) as a practical expedient, with changes in value reported in income from other invested assets. In applying the equity method or fair value using net asset value (or its equivalent) as a practical expedient, these investments are initially recorded at cost and are subsequently adjusted based on the Company’s proportionate share of the net income or loss of the partnership or changes in fair value. We have elected to classify distributions received from these investments using the cumulative earnings approach. Due to the timing of receiving financial information from these partnerships, the results are generally reported on a one month or quarter lag.

Long-Lived Assets

Long-Lived AssetsProperty and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets. Repairs and maintenance are charged to expense as incurred. Estimated useful lives are 5 years for furniture and fixtures and 2 to 3 years for equipment, computer hardware and purchased software. Certain costs associated with the acquisition or development of internal-use software are capitalized. Once the software is ready for its intended use, these costs are amortized on a straight-line basis over the software's expected useful life, which is generally 3 years. We amortize leasehold improvements over the shorter of the lives of the leases or estimated service lives of the leasehold improvements.

Deferred Policy Acquisition Costs

Deferred Policy Acquisition CostsWe defer certain personnel costs and premium tax expense directly related to the successful acquisition of new insurance policies and amortize these costs over the period the related estimated gross profits are recognized in order to match costs and revenues. We do not defer any underwriting costs associated with our contract underwriting services. Costs related to the acquisition of mortgage insurance business are initially deferred and reported as deferred policy acquisition costs. Consistent with industry accounting practice, amortization of these costs for each underwriting year book of business is recognized in proportion to estimated gross profits. Estimated gross profits are composed of earned premium, interest income, losses and loss adjustment expenses. The deferred costs are adjusted as appropriate for policy cancellations to be consistent with our revenue recognition policy. We estimate the rate of amortization to reflect actual experience and any changes to persistency or loss development. Deferred policy acquisition costs are reviewed periodically to determine that they do not exceed recoverable amounts, after considering investment income.

Insurance Premium Revenue Recognition

Mortgage guaranty insurance policies are contracts that are generally non-cancelable by the insurer, are renewable at a fixed price, and provide for payment of premium on a monthly, annual or single basis. Upon renewal, we are not able to re-underwrite or re-price our policies. Consistent with industry accounting practices, premiums written on a monthly basis are earned as coverage is provided. Monthly policies accounted for 94% of earned premium in 2022. Premiums written on an annual basis are amortized on a pro rata basis over the year of coverage. Primary mortgage insurance written on policies covering more than one year are referred to as single premium policies. A portion of the revenue from single premium policies is recognized in earned premium in the current period, and the remaining portion is deferred as unearned premium and earned over the expected life of the policy. If single premium policies related to insured loans are cancelled due to repayment by the borrower, and the premium is non-refundable, then the remaining unearned premium related to each cancelled policy is recognized as earned premium upon notification of the cancellation. The Company recorded $20.8 million and $63.8 million of earned premium related to policy cancellations for the years ended December 31, 2022 and 2021, respectively. Unearned premium represents the portion of premium written that is applicable to the estimated unexpired risk of insured loans. Rates used to determine the earning of single premium policies are estimates based on an analysis of the expiration of risk.

Reserve for Losses and Loss Adjustment Expenses

We establish reserves for losses based on our best estimate of ultimate claim costs for defaulted loans using the general principles contained in ASC No. 944, in accordance with industry practice. However, consistent with industry standards for mortgage insurers, we do not establish loss reserves for future claims on insured loans which are not currently in default. Loans are classified as in default when the borrower has missed two consecutive payments. Once we are notified that a borrower has defaulted, we will consider internal and third-party information and models, including the status of the loan as reported by its servicer and the type of loan product to determine the likelihood that a default will reach claim status. In addition, we will project the amount that we will pay if a default becomes a claim (referred to as "claim severity"). Based on this information, at each reporting date we determine our best estimate of loss reserves at a given point in time. Included in loss reserves are reserves for incurred but not reported ("IBNR") claims. IBNR reserves represent our estimated unpaid losses on loans that are in default, but have not yet been reported to us as delinquent by our customers. We will also establish reserves for associated loss adjustment expenses, consisting of the estimated cost of the claims administration process, including legal and other fees and expenses associated with administering the claims process. Establishing reserves is inherently subjective as it requires estimates that are susceptible to significant revision as more information becomes available. Our estimates of claim rates and claim sizes will be strongly influenced by prevailing economic conditions, such as the overall state of the economy, current rates or trends in unemployment, changes in housing values and/or interest rates, and our best judgments as to the future values or trends of these macroeconomic factors. Losses incurred are also generally affected by the characteristics of our insured loans, such as the loan amount, loan-to-value ratio, the percentage of coverage on the insured loan and the credit quality of the borrower.

Premium Deficiency Reserve

Premium Deficiency ReserveWe are required to establish a premium deficiency reserve if the net present value of the expected future losses and expenses for a particular group of policies exceeds the net present value of expected future premium, anticipated investment income and existing reserves for that specified group of policies. We reassess our expectations for premium, losses and expenses of our mortgage insurance business periodically and update our premium deficiency analysis accordingly.

Derivative Instruments

Derivative instruments, including embedded derivative instruments, are recognized at fair value in the consolidated balance sheets. The amount of monthly reinsurance premiums ceded under our reinsurance contracts will fluctuate due to changes in one-month LIBOR or SOFR and changes in money market rates. As the reinsurance premium will vary based on changes in these rates, we concluded that these reinsurance agreements contain embedded derivatives that are accounted for separately like freestanding derivatives.

Stock-Based Compensation

We measure the cost of employee services received in exchange for awards of equity instruments at the grant date of the award using a fair value based method. Fair value is determined on the date of grant based on quoted market prices. We recognize compensation expense on nonvested shares over the vesting period of the award. Excess tax benefits and tax deficiencies associated with share-based payments are recognized as income tax expense or benefit in the income statement and treated as discrete items in the reporting period.

Income Taxes

Deferred income tax assets and liabilities are determined using the asset and liability (balance sheet) method. Under this method, we determine the net deferred tax asset or liability based on the tax effects of the temporary differences between the book and tax bases of the various assets and liabilities and give current recognition to changes in tax rates and laws. Changes in tax laws, rates, regulations and policies, or the final determination of tax audits or examinations, could materially affect our tax estimates. We evaluate the realizability of the deferred tax asset and recognize a valuation allowance if, based on the weight of all available positive and negative evidence, it is more likely than not that some portion or all of the deferred tax asset will not be realized. When evaluating the realizability of the deferred tax asset, we consider estimates of expected future taxable income, existing and projected book/tax differences, carryback and carryforward periods, tax planning strategies available, and the general and industry specific economic outlook. This realizability analysis is inherently subjective, as it requires management to forecast changes in the mortgage market, as well as the related impact on mortgage insurance, and the competitive and general economic environment in future periods. Changes in the estimate of deferred tax asset realizability, if applicable, are included in income tax expense on the consolidated statements of comprehensive income.

ASC No. 740 provides a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. In accordance with ASC No. 740, before a tax benefit can be recognized, a tax position is evaluated using a threshold that it is more likely than not that the tax position will be sustained upon examination. When evaluating the more-likely-than-not recognition threshold, ASC No. 740 provides that a company should presume the tax position will be examined by the appropriate taxing authority that has full knowledge of all relevant information. If the tax position meets the more-likely-than-not recognition threshold, it is initially and subsequently measured as the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement.

As described in Note 12, we purchase non-interest-bearing United States Mortgage Guaranty Tax and Loss Bonds ("T&L Bonds") issued by the Treasury Department. These assets are carried at cost and are reported as prepaid federal income tax on the consolidated balance sheets.

It is our policy to classify interest and penalties as income tax expense and to use the aggregate portfolio approach to release income tax effects from accumulated other comprehensive income.

Earnings per Share

Basic earnings per common share amounts are calculated based on income available to common stockholders and the weighted average number of common shares outstanding during the reporting period. Diluted earnings per common share amounts are calculated based on income available to common stockholders and the weighted average number of common and potential common shares outstanding during the reporting period. Potential common shares, composed of the incremental common shares issuable upon vesting of unvested common shares and common share units, are included in the earnings per share calculation to the extent that they are dilutive.

Recently Issued Accounting Standards

Accounting Standards Not Yet Adopted

In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. The amendments in this update provide temporary optional guidance to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform. It provides optional expedients and exceptions for applying generally accepted accounting principles to contract, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. This standard may be elected and applied prospectively over time from March 12, 2020 through December 31, 2024, as amended by ASU 2022-06, as reference rate reform activities occur. The adoption of, and future elections under, this ASU are not expected to have a material impact on our consolidated financial statements as the ASU will ease, if warranted, the requirements for accounting for the future effects of the rate reform. We continue to monitor the impact the discontinuance of LIBOR or another reference rate will have on our contracts and other transactions.

In June 2022, the FASB issued ASU No. 2022-03, Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions. This update clarifies the guidance in ASC 820 on the fair value measurement of an equity security that is subject to a contractual sale restriction and requires specific disclosures related to such an equity security. The update clarifies that a contractual sale restriction prohibiting the sale of an equity security is a characteristic of the reporting entity holding the equity security and is not included in the equity security's unit of account. Accordingly, an entity should not consider the contractual sale restriction when measuring the equity security’s fair value. The update also requires specific disclosures related to equity securities that are subject to contractual sale restrictions, including (1) the fair value of such equity securities reflected in the balance sheet, (2) the nature and remaining duration of the corresponding restrictions, and (3) any circumstances that could cause a lapse in the restrictions. The ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within those fiscal years, with early adoption permitted. The adoption of this ASU is not expected to have a material effect on the Company's consolidated operating results or financial position.

Fair Value of Financial Instruments

Fair Value of Financial InstrumentsWe carry certain of our financial instruments at fair value. We define fair value as the current amount that would be exchanged to sell an asset or transfer a liability, other than in a forced liquidation.

Fair Value Hierarchy

ASC No. 820 specifies a hierarchy of valuation techniques based on whether the inputs to those valuation techniques are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect our market assumptions. The level within the fair value hierarchy to measure the financial instrument shall be determined based on the lowest level input that is significant to the fair value measurement. The three levels of the fair value hierarchy are as follows:

•Level 1—Quoted prices for identical instruments in active markets accessible at the measurement date.

•Level 2—Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and valuations in which all significant inputs are observable in active markets. Inputs are observable for substantially the full term of the financial instrument.

•Level 3—Valuations derived from one or more significant inputs that are unobservable.

Determination of Fair Value

When available, we generally use quoted market prices to determine fair value and classify the financial instrument in Level 1. In cases where quoted market prices for similar financial instruments are available, we utilize these inputs for valuation techniques and classify the financial instrument in Level 2. In cases where quoted market prices are not available, fair values are based on estimates using discounted cash flows, present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rates and estimates of future cash flows and we classify the financial instrument in Level 3. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument.

We used the following methods and assumptions in estimating fair values of financial instruments:

•Investments available for sale—Investments available for sale are valued using quoted market prices in active markets, when available, and those investments are classified as Level 1 of the fair value hierarchy. Level 1 investments available for sale include investments such as U.S. Treasury securities and money market funds. Investments available for sale are classified as Level 2 of the fair value hierarchy if quoted market prices are not available and fair values are estimated using quoted prices of similar securities or recently executed transactions for the securities. U.S. agency securities, U.S. agency mortgage-backed securities, municipal debt securities, non-U.S. government securities, corporate debt securities, residential and commercial mortgage securities and asset-backed securities are classified as Level 2 investments.

We use independent pricing sources to determine the fair value of securities available for sale in Level 1 and Level 2 of the fair value hierarchy. We use one primary pricing service to provide individual security pricing based on observable market data and receive one quote per security. To ensure securities are appropriately classified in the fair value hierarchy, we review the pricing techniques and methodologies of the independent pricing service and believe that their policies adequately consider market activity, either based on specific transactions for the issue valued or based on modeling of securities with similar credit quality, duration, yield and structure that were recently traded. U.S. agency securities, U.S. agency mortgage-backed securities, municipal debt securities, non-U.S. government securities, and corporate debt securities are valued by our primary vendor using recently executed transactions and proprietary models based on observable inputs, such as interest rate spreads, yield curves and credit risk. Residential and commercial mortgage securities and asset-backed securities are valued by our primary vendor using proprietary models based on observable inputs, such as interest rate spreads, prepayment speeds and credit risk. As part of our evaluation of investment prices provided by our primary pricing service, we obtained and reviewed their pricing methodologies which include a description of how each security type is evaluated and priced. We review the reasonableness of prices received from our primary pricing service by comparison to prices obtained from additional pricing sources. We have not made any adjustments to the prices obtained from our primary pricing service.