Restricted cash and cash equivalents represent cash and cash equivalents held in trust in order to secure certain of the Company's obligations and, accordingly, are restricted as to withdrawal or usage. As of December 31, 2021 and 2020 the Company held $3.1 million and $3.2 million, respectively, in cash and investments in trust for reinsurance obligations, of which $0.2 million, represented restricted cash and cash equivalents for each year.

Beginning in 2020, with the adoption of ASU 2016-13, Financial Instruments - Credit Losses (Topic 326), the Company's investments in fixed maturity securities are presented net of an allowance for current expected credit losses (CECL). The Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria is met, the security's amortized cost basis is written down to its fair value. For AFS debt securities that do not meet either criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. The changes in the Company's allowance for CECL on investments are included in Net realized and unrealized gains on investments on the Company's Consolidated Statements of Comprehensive Income (see Note 6).

Prior to adoption of ASU 2016-13, Financial Instruments - Credit Losses (Topic 326), the determination of an other-than-temporary decline for fixed maturity securities and other invested assets included, in addition to other relevant factors, a presumption that if the market value was below cost by a significant amount for a period of time, a bifurcation of the write-down may be necessary based on the portion of the loss that was deemed to be a "credit loss", which was considered a realized loss, and the portion that was deemed to be an "other than credit loss", which was considered to be an unrealized loss. If management had the intent to sell the security or more likely than not would be required to sell the security before its anticipated recovery, the investment was written down to its fair value and the entire impairment was recorded as a realized loss in the Company's Consolidated Statements of Comprehensive Income. If management did not have the intent to sell or would not be required to sell the security but did not expect to recover the amortized cost or cost basis of the security, the amount of the other-than-temporary impairment was bifurcated (see Note 5).

Investment income consists primarily of interest and dividends generated by investment securities. Interest is recorded as earned on an accrual basis and dividends are recorded as earned at the ex-dividend date. Interest income on mortgage-backed and asset-backed securities is determined using the effective-yield method based on estimated principal repayments. Mortgage-backed securities are adjusted for the effects of changes in prepayment assumptions on the related accretion of discount or amortization of premium of such securities using the retrospective method.

Premiums written are recognized as revenues, net of any applicable underlying reinsurance coverage, and recognized as earned, over the period of the contract in proportion to the amount of insurance protection provided. At the end of the policy term, payroll-based premium audits are performed on substantially all policyholder accounts to determine the actual amount of net premiums earned for that policy year. Earned but unbilled premiums include estimated future audit premiums based on the Company's historical experience. These estimates are subject to changes in policyholders' payrolls, economic conditions, and seasonality, and are continually reviewed and adjusted as experience develops or new information becomes known. Any such adjustments are included in current operations; however, they are partially offset by the resulting changes in losses and LAE, commission expenses, and premium taxes. The Company's premiums receivable on its Consolidated Balance Sheets included $13.8 million and $2.3 million of additional premiums expected to be received from policyholders for premium audits at December 31, 2021 and 2020, respectively.

The Company establishes an allowance for CECL (see Note 6) on its premiums receivable through a charge included in underwriting and general and administrative expenses in its Consolidated Statements of Comprehensive Income. This allowance for CECL is determined based on estimates (collectability and historical payment patterns) and assumptions to project future experience. After all collection efforts have been exhausted, the Company reduces the allowance for CECL for write-offs of premiums receivable that have been deemed uncollectible. The Company's allowance for CECL was $10.3 million and $10.8 million at December 31, 2021 and 2020, respectively. The Company had write offs of $2.5 million, $6.8 million, and $10.5 million for the years ended December 31, 2021, 2020, and 2019, respectively.

Policy acquisition costs, those costs that relate directly to the successful acquisition of new or renewal insurance contracts, including underwriting, policy issuance and processing, medical and inspection, sales force contract selling and commissions are deferred and amortized as the related premiums are earned. Amortization of deferred policy acquisition costs for the years ended December 31, 2021, 2020, and 2019, was $92.2 million, $97.5 million, and $107.7 million, respectively.

If the sum of a policy's expected losses and LAE and deferred policy acquisition costs exceeds the related unearned premiums and projected investment income, a premium deficiency is determined to exist. In this event, deferred policy acquisition costs are immediately expensed to the extent necessary to eliminate the premium deficiency. If the premium deficiency exceeds deferred acquisition costs, a liability is accrued for the excess deficiency. There were no premium deficiency adjustments recognized during the years ended December 31, 2021, 2020, and 2019.

Unpaid loss and LAE reserves represent management's best estimate of the ultimate net cost of all reported and unreported losses incurred for the applicable periods, less payments made. The estimated reserves for losses and LAE include the accumulation of estimates for all claims reported prior to the balance sheet date, estimates of claims incurred but not reported, and estimates of expenses for investigating and adjusting all incurred and unadjusted claims (based on projections of relevant historical data). Amounts reported are subject to the impact of future changes in economic, regulatory and social conditions. Management believes that, subject to the inherent variability in any such estimate, the reserves are within a reasonable and acceptable range of adequacy. Estimates for claims prior to the balance sheet date are continually monitored and reviewed, and as settlements are made or reserves adjusted, the differences are reported in current operations. Salvage and subrogation recoveries are estimated based on a review of the level of historical salvage and subrogation recoveries.

In the ordinary course of business, the Company purchases excess of loss reinsurance in order to protect it against the impact of large and/or catastrophic losses. Additionally, the Company is a party to the LPT Agreement (see Note 10). These reinsurance arrangements reduce the Company's exposure to such losses since its reinsurers are liable to the Company to the extent of the reinsurance protection provided. However, the Company remains liable for all losses it incurs to the extent that any reinsurer is unable or unwilling to make timely payments under its reinsurance agreements.

Balances due from reinsurers on unpaid losses, including an estimate of such recoverables related to reserves for incurred but not reported losses, are reported as reinsurance recoverables on the Company's Consolidated Balance Sheets. Reinsurance recoverables on paid losses represent amounts currently due from reinsurers. Reinsurance recoverables on unpaid losses represent amounts that will be collectible from reinsurers once the losses are paid. Reinsurance recoverables on unpaid losses and LAE amounted to $476.3 million and $496.6 million at December 31, 2021 and 2020, respectively.

Beginning in 2020, with the adoption of ASU 2016-13, the Company's reinsurance recoverables are presented net of an allowance for CECL. The changes in the Company's allowance for CECL are included in underwriting and general and administrative expenses on the Company's Consolidated Statements of Comprehensive Income (see Note 6). This allowance for CECL is determined based on historical information, financial strength of reinsurers, collateralization amounts and ratings to determine the appropriateness of the allowance.

Pursuant to the LPT Agreement, LAE is deemed to be 7% of total losses paid and is payable to the Company as compensation for management of the claims under the LPT Agreement. The Deferred Gain is amortized using the recovery method, whereby the amortization is determined by the proportion of actual reinsurance recoveries to total estimated recoveries through the life of the LPT Agreement, and is recorded in losses and LAE incurred in the Company's Consolidated Statements of Comprehensive Income. Any adjustment to the estimated loss and LAE reserves ceded under the LPT Agreement results in a cumulative adjustment to the Deferred Gain, which is also recognized in losses and LAE incurred in the Company's Consolidated Statements of Comprehensive Income, such that the Deferred Gain reflects the balance that would have existed had the revised reserves been recognized at the inception of the LPT Agreement (LPT Reserve Adjustment).

Additionally, the Company is entitled to receive a contingent profit commission under the LPT Agreement. The contingent profit commission is equal to 30% of the favorable difference between actual paid losses and LAE and expected paid losses and LAE as established in the LPT Agreement based on losses paid through June 30, 2024. The contingent profit commission is paid every five years beginning June 30, 2004 for the first 25 years of the agreement. The Company could be required to return any previously received contingent profit commission, plus interest, in the event of unfavorable differences through June 30, 2024. The Company records an estimate of contingent profit commission on its Consolidated Balance Sheets as Contingent commission receivable–LPT Agreement and a corresponding liability is recorded as Deferred reinsurance gain–LPT Agreement. The Contingent commission receivable–LPT Agreement is reduced as amounts are received from participating reinsurers. In 2019, the Company received $19.1 million in cash related to the contingent profit commission. The Deferred reinsurance gain–LPT Agreement is amortized using the recovery method. The amortization of the contingent profit commission is determined by the proportion of actual reinsurance recoveries to total estimated recoveries over the life of the contingent profit commission (through June 30, 2024), and is recorded in losses and LAE incurred in the Company's Consolidated Statements of Comprehensive Income. Any adjustment to the contingent profit commission under the LPT Agreement results in a cumulative adjustment to the Deferred Gain, which is also recognized in losses and LAE incurred in the Company's Consolidated Statements of Comprehensive Income, such that the Deferred Gain reflects the balance that would have existed had the revised contingent profit commission been recognized at the inception of the LPT Agreement (LPT Contingent Commission Adjustment).

Electronic data processing equipment, software, furniture and equipment, and automobiles are depreciated using the straight-line method over three to seven years. Leasehold improvements are also carried at cost less accumulated amortization. The Company amortizes leasehold improvements using the straight-line method over the lesser of the useful life of the asset or the remaining original lease term, excluding options or renewal periods. Leasehold improvements are generally amortized over three to eight years.

The Company capitalizes software license fees and implementation costs associated with hosting arrangements that are service contracts. These amounts are included in Cloud computing arrangements on the Company's Consolidated Balance Sheets. Amortization of the software license fees is calculated using the straight-line method over the term of the service contract or based on the expected utilization of the asset. Amortization of the implementation costs are calculated using the straight-line method based on the term of the service contract and commence once the module or component is ready for its intended use,

The Company determines if an arrangement is a lease at the inception of the transaction. Leased office property meets the definition of operating leases under ASC 842 and is presented as a right-of-use asset (ROU asset) and lease liability on the Company's Consolidated Balance Sheets. ROU assets represent the right to use an underlying asset for the lease payments arising from the lease transaction. Operating lease ROU assets and liabilities are recognized at the commencement date based on the present value of the lease payments over the lease term. The Company uses collateralized incremental borrowing rates to determine the present value of lease payments. The ROU assets also include lease payments less any lease incentives within a lease agreement. The Company's lease terms may include options to extend or terminate a lease. Lease expense for lease payments is recognized on a straight-line basis over the lease term.

Leased property and equipment meeting finance lease criteria are capitalized at the lower of the present value of the related lease payments or the fair value of the leased asset at the inception of the lease. Financing leases for automobiles are included in property and equipment in other liabilities on the Company's Consolidated Balance Sheets. Amortization is calculated using the straight-line method based on the term of the lease and is included in the depreciation expense of property and equipment. See Note 12 for additional disclosures related to finance leases.

The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the Company's financial statements. Under this method, the Company determines deferred tax assets and liabilities on the basis of the differences between the financial statement and tax bases of assets and liabilities by using enacted tax rates in effect for the year in which the differences are expected to reverse. As of December 22, 2017, the date that the Tax Cuts and Jobs Act was enacted (Enactment), the effect of the change in tax rates on the Company's deferred tax assets and liabilities was recognized in income and created stranded tax effects within accumulated other comprehensive income that did not reflect the newly enacted tax rate. The Company reclassified the net tax effects from Accumulated other comprehensive income, net of tax, to Retained earnings as of the date of Enactment.

The Company records uncertain tax positions in accordance with ASC 740, Income Taxes, on the basis of a two-step process. Recognition (Step 1) occurs when the Company concludes that a tax position, based solely on its technical merits, is more likely than not to be sustained upon examination. Measurement (Step 2) is addressed only if Step 1 has been satisfied. Under Step 2, the tax benefit is measured as the largest amount of benefit, determined on a cumulative probability basis, that is more likely than not to be realized upon ultimate settlement.

The Company recognizes deferred tax assets when it determines that such assets are more likely than not to be realized in future periods. In making such a determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, tax-planning strategies, projected future taxable income, projected future tax rates, and results of recent operations. If the Company determines that it is not more likely than not that it could realize its deferred tax assets in future periods, it would establish a deferred tax asset valuation allowance that would increase the Company's provision for income taxes. If the Company determines that it would be able to realize its deferred tax assets in the future in excess of its net recorded amount, the Company would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes.

The Company's cash equivalents and short-term investments include investments in money market securities and securities backed by the U.S. government. The Company's investment securities are diversified throughout many industries and geographic regions and include investments in U.S. government and U.S. government-sponsored enterprises. The Company believes that it has no significant concentrations of credit risk from a single issue or issuer within its cash equivalents, short-term investments and investment securities other than concentrations in U.S. government and U.S. government-sponsored enterprises.

The Company monitors the financial condition of its reinsurers to minimize its exposure to significant losses from reinsurer insolvencies. The Company also obtains collateral from its reinsurers in order to mitigate the risks related to insolvencies. At December 31, 2021, $1.8 million was held as collateral by cash or letters of credit for the Company's reinsurance recoverables and an additional $432.5 million was in trust accounts for reinsurance recoverables specifically related to the LPT Agreement.

The fair values of the Company's financial instruments have been determined using available market information and other appropriate valuation methodologies. Judgment is required in developing fair value estimates where quoted market prices are not available. Accordingly, these estimates are not necessarily indicative of the amounts that could be realized in a current market exchange. The use of different market assumptions or estimating methodologies may have an effect on the estimated fair value amounts.

The Company formally tests for impairment of goodwill and intangible assets in the fourth quarter of each year. At the end of each quarter, management considers the results of the previous analysis as well as any recent developments that may constitute triggering events requiring the impairment analysis of goodwill and other intangible assets to be updated. The Company assessed the effects of current economic conditions on the Company's financial condition and results of operations and changes in the Company's fair value and determined that there were no impairments of these assets as of December 31, 2021 and 2020.