Organization and Summary of Significant Accounting Policies	9 Months Ended
Sep. 30, 2018
Accounting Policies [Abstract]
Organization and Summary of Significant Accounting Policies	NOTE 1. ORGANIZATION & SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Unless the context requires otherwise, the terms “we,” “us,” “our” or “our Company” are used to mean The Navigators Group, Inc., a Delaware holding company established in 1982, and its subsidiaries. The term “Parent Company” is used to mean The Navigators Group, Inc. without its subsidiaries. Organization We are an international insurance company with a long-standing area of specialization in Marine insurance. We also offer Property and Casualty (“P&C”) insurance, primarily general liability coverage and umbrella & excess liability coverage to commercial enterprises through our Primary and Excess Casualty divisions. We have also developed niches in Professional Liability insurance, through our Directors & Officers (“D&O”) and Errors & Omissions (“E&O”) divisions, as well as assumed reinsurance products. We operate through various wholly-owned insurance and service companies. Our subsidiaries domiciled in the United States (“U.S.”) include two insurance companies, Navigators Insurance Company (“NIC”) and Navigators Specialty Insurance Company (“NSIC”), as well as our U.S. underwriting agency, Navigators Management Company (“NMC”). NIC includes a branch in the United Kingdom (“U.K”). We also have operations domiciled in the U.K., Hong Kong and Europe. Navigators International Insurance Company Ltd. (“NIIC”), Navigators Management (U.K.) Ltd. (“NMUK”) and Navigators Underwriting Ltd. (“NUL”) are domiciled in the U.K. and NUL includes European branches. Navigators Underwriting Agency Ltd. (“NUAL”), a Lloyd’s of London (“Lloyd’s”) underwriting agency, manages and provides the capital, through Navigators Corporate Underwriters Ltd. (“NCUL”), for our Lloyd’s Syndicate 1221 (the “Syndicate”), and is also domiciled in the U.K. We control 100% of the Syndicate’s stamp capacity. On June 7, 2018, we acquired 100% ownership interest in Bracht, Deckers & Mackelbert NV, an insurance underwriting agency organized under the laws of Belgium (“BDM”) and Assurances Continentales – Continentale Verzekeringen NV, an insurance company licensed under the laws of Belgium (“ASCO”). The acquisition was accounted for in accordance with Accounting Standards Codification (“ASC”) 805, “Business Combinations.” Refer to Note 2. Merger and Business Combinations and Note 6. Goodwill and Intangible Assets for further information regarding the acquisition. On August 22, 2018, our Company entered into an Agreement and Plan of Merger (the “Merger Agreement”) with The Hartford Financial Services Group, Inc. (“The Hartford”). The Merger Agreement provides that, subject to the terms and conditions set forth therein, our Company will merge with an existing subsidiary of The Hartford, with our Company surviving as a wholly owned subsidiary of The Hartford (the “Merger”). Refer to Note 2. Merger and Business Combinations for further information. Basis of Presentation The Consolidated Balance Sheet at September 30, 2018 and the Consolidated Statements of Income (Loss), Comprehensive Income (Loss), Stockholders’ Equity and Cash Flows for the periods ended September 30, 2018 and 2017 are unaudited. The Balance Sheet at December 31, 2017 is derived from our audited Financial Statements. The accompanying Interim Consolidated Financial Statements reflect all adjustments, which, in the opinion of management, are necessary to fairly present the results of our Company for the interim periods presented on the basis of U.S. generally accepted accounting principles (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X as promulgated by the U.S. Securities and Exchange Commission. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. All significant intercompany transactions and balances have been eliminated in consolidation. The preparation of these Financial Statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the Financial Statements and the reported revenues and expenses during the reporting periods. The results of operations for any interim period are not necessarily indicative of results for the full year. The Interim Consolidated Financial Statements should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2017. Certain amounts for the prior period have been reclassified to conform with the current period presentation. Income Taxes On December 22, 2017, the Tax Cuts and Jobs Act (the “Tax Act”) was enacted into law and the new legislation contained several key tax provisions that affected us, including a one-time mandatory Deemed Repatriation Transition Tax (the “Transition Tax”) on accumulated foreign earnings and a reduction of the corporate income tax rate to 21% effective January 1, 2018, among others. We were required to recognize the effect of the tax law changes in the period of enactment, such as determining the Transition Tax, re-measuring our U.S. deferred tax assets and liabilities as well as reassessing the net realizability of our deferred tax assets and liabilities. In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118 (“SAB 118”), Income Tax Accounting Implications of the Tax Act, which allowed us to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. During the fourth quarter of 2017, we made a reasonable estimate of the effects on our deferred tax balances and recognized provisional tax amounts of $2.6 million related to the Transition Tax. As of September 30, 2018, we have finalized the calculation of the Transition Tax which resulted in a decrease in the provisional amount of $1.3 million and has been reflected as a discrete item in our Effective Tax Rate calculation. We will continue to evaluate the estimated effects on our deferred tax balances during the measurement period. The interim income tax provision has been computed based on our estimated annual Effective Tax Rate, which represents our best estimate on a year to date basis for the interim period. As a result, the tax provision for a given quarter equals the difference between the provision recorded cumulatively year to date less the amount recorded cumulatively as of the end of the prior interim period. Our Effective Tax Rate for the quarter differs from the federal tax rate of 21% primarily due to tax-exempt investment income, the dividends received deduction, Transition Tax benefit, and an excess tax benefit related to the vesting of stock compensation at fair market value. Short-Term Investments Reclassifications Cash and overseas deposits that were misclassified within Short-Term Investments were reclassified representing an immaterial correction. Cash of $20.5 million as of December 31, 2017 was reclassified from Short-Term Investments to Cash and Cash Equivalents. Overseas deposits of $28.8 million as of December 31, 2017 were reclassified from Short-Term Investments to Other Invested Assets. The reclassification of cash within Short-Term Investments to Cash and Cash Equivalents impacted the Statement of Cash Flows for the nine months ended September 30, 2017 by decreasing Net Cash Used in Investing Activities by $9.2 million. New Accounting Standards Adopted in 2018 Revenue From Contracts With Customers Effective January 1, 2018, our Company adopted ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)”. This guidance affects any contracts with customers to transfer goods or services or for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (for example, insurance contracts are not in scope of the new guidance). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Our Company generates an insignificant amount of fee income that is within the scope of this guidance and was not materially impacted by the adoption of this guidance. The adoption of this guidance did not have a material impact on our results of operations, financial condition or liquidity. Classification and Measurement of Financial Instruments Effective January 1, 2018, our Company adopted ASU 2016-01 “Financial Instruments – Overall (Subtopic 825-10) – Recognition and Measurement of Financial Assets and Financial Liabilities”. This guidance requires equity investments (except those accounted for under the equity method of accounting, investments that are consolidated or those that meet a practicability exception) to be measured at fair value with changes in fair value recognized in net income, simplifies the impairment assessment of equity investments without readily determinable values by requiring a qualitative assessment to identify impairment, eliminates the requirement to disclose the methods and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost, requires the use of the exit price notion when measuring the fair value of financial instruments for disclosure purposes, requires separate presentation in other comprehensive income of the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the organization has elected to measure the liabilities in accordance with the fair value option, requires the separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or the accompanying notes to the financial statements and clarifies that the reporting organization should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the organization’s other deferred tax assets. As of January 1, 2018, the adoption of this guidance resulted in a $7.7 million net after-tax increase to Retained Earnings with a corresponding decrease to Accumulated Other Comprehensive Income (Loss), resulting in no change to our Total Stockholders’ Equity. This adjustment reflects the cumulative effect adjustment to reclassify Net Unrealized Gain on Investments in Accumulated Other Comprehensive Income (Loss) for available-for-sale Equity Securities to Retained Earnings upon adoption. Upon the adoption of this guidance, Equity Securities have been measured at fair value with changes in fair value recognized in Net Income through Net Unrealized Gains (Losses) on Equity Securities. The other aspects of this guidance only impacted disclosure or did not apply to our Company and therefore did not impact our results of operations, financial condition or liquidity. Cash Flows Effective January 1, 2018, our Company adopted ASU 2016-15, “Statement of Cash Flows (Topic 230) – Classification of Certain Cash Receipts and Cash Payments” which addresses diversity in practice in how eight specific cash receipts and cash payments should be presented and classified on the statement of cash flows. The adoption of this guidance did not impact our results of operations, financial condition or liquidity. Effective January 1, 2018, our Company adopted ASU 2016-18, “Statement of Cash Flows (Topic 230) – Restricted Cash” which addresses diversity in practice in the classification and presentation of changes in restricted cash on the statement of cash flows. This guidance requires a statement of cash flows to explain the change during the period in the total of cash, cash equivalents, restricted cash and restricted cash equivalents. Transfers between cash and cash equivalents and restricted cash and restricted cash equivalents will no longer be presented on the statement of cash flows. To assist in meeting the requirements of this guidance to provide a reconciliation from the Statement of Cash Flows to the Balance Sheet, upon adoption of this guidance our Company added new accounts titled “Cash and Cash Equivalents” and “Restricted Cash and Cash Equivalents” and reclassified amounts previously held in Short-Term Investments to these accounts for all periods presented. This resulted in the reclassification of $71.3 million of restricted and unrestricted cash and cash equivalent balances as of December 31, 2017. This guidance was adopted on a retrospective basis. Prior to the adoption of this guidance, restricted and unrestricted cash and cash equivalent balances included in the Short-Term Investments account had been presented as a cash flow provided by (used in) investing activities. Consequently, the Statement of Cash Flows for the nine months ended September 30, 2017 includes a revision to decrease “Net Cash Used in Investing Activities” by $76.8 million. Income Taxes Effective January 1, 2018, our Company adopted ASU 2016-16, “Income Taxes (Topic 740) – Intra-Entity Transfers of Assets Other than Inventory” that requires companies to account for the income tax effects of intercompany transfers of assets other than inventory when the transfer occurs. The adoption of this guidance did not impact our results of operations, financial condition or liquidity. Definition of a Business Effective January 1, 2018, our Company adopted ASU 2017-01, “Clarifying the Definition of a Business” that provides guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. This guidance will be applied to transactions prospectively. The adoption of this guidance did not impact our results of operations, financial condition or liquidity. Tax Reform Reclassification from Other Comprehensive Income Effective January 1, 2018, our Company early adopted ASU 2018-02, “Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income” that permits entities to reclassify tax effects stranded in accumulated other comprehensive income as a result of tax reform to retained earnings. The total impact of the remeasurement and other adjustments was reflected in 2017 income from continuing operations, regardless of where deferred taxes were originally recorded. As of January 1, 2018, the adoption of this guidance resulted in a one-time reclassification of $2.8 million, decreasing Retained Earnings and increasing Accumulated Other Comprehensive Income (Loss) primarily from the remeasurement of deferred tax assets and liabilities associated with unrealized gains and losses on investments and currency translation adjustments using the 21% corporate tax rate. Recently Issued Accounting Standards Not Yet Adopted Fair Value Measurement Disclosure In August 2018, the FASB issued ASU 2018-13, “Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement”, which eliminates, adds, and modifies certain disclosure requirements for fair value measurements. The guidance eliminates the requirement to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for the timing of transfers between levels of the fair value hierarchy, and the valuation processes for Level 3 fair value measurements. The guidance adds the requirement to disclose changes in unrealized gains and losses included in other comprehensive income for the period and to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. The guidance modifies disclosures around the use of the practical expedient to measure the fair value of certain investments at their net asset values and modifies the requirement to disclose information as of the reporting date about the measurement uncertainty of Level 3 fair value measurement. This guidance is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted for the entire standard or only the provisions that eliminate or modify requirements. This guidance will be adopted on a prospective and retrospective basis, where applicable and as required. As this new guidance is disclosure-related only, adoption will not impact our results of operations, financial condition or liquidity. Implementation Costs in a Cloud Computing Arrangement In August 2018, the FASB issued ASU 2018-15, “Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract”, which requires companies to follow the internal-use software guidance in ASC 350-40 (Intangibles - Goodwill and Other - Internal-Use Software) to determine which implementation costs to capitalize as an asset and which costs to expense. Capitalized implementation costs will be amortized over the term of the service arrangement, beginning when the service arrangement or a component of the arrangement is ready for its intended use. This guidance is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted. This guidance will be applied prospectively. The adoption of this guidance is not expected to materially impact our results of operations, financial condition or liquidity. Significant Accounting Policies There were no notable changes in our significant accounting policies subsequent to our Annual Report on Form 10-K for the year ended December 31, 2017, with the exception of changes related to the adoption of ASU 2016-01 and ASU 2016-18 impacting the following accounting policies: Cash and Cash Equivalents and Restricted Cash and Cash Equivalents Cash includes cash on hand and demand deposits with banks. Cash Equivalents include highly liquid investments with original maturities of three months or less including money-market funds. Restricted Cash and Cash Equivalents primarily relates to funds that are held to support regulatory and contractual obligations. Investments Fixed Maturities held by our Company were carried at fair value and classified as available-for-sale. Available-for-sale securities are debt securities not classified as either held-to-maturity securities or trading securities and are reported at fair value, with unrealized gains and losses excluded from earnings and reported in Accumulated Other Comprehensive Income (“AOCI”) as a separate component of Stockholders’ Equity. Fixed Maturities include bonds, mortgage-backed and asset-backed securities, and redeemable preferred stocks. Upon adoption of ASU 2016-01 on January 1, 2018, Equity Securities held by our Company were carried at fair value with any changes in fair value recognized in Net Income through the Net Unrealized Gains (Losses) on Equity Securities account. Prior to the adoption of ASU 2016-01, Equity Securities were carried at fair value and classified as available-for-sale. For our policy on Equity Securities classified as available-for-sale, refer to Note 1 within our Annual Report on Form 10-K for the year ended December 31, 2017. Equity Securities consist of common stock, exchange traded funds, mutual funds and preferred stock. Other Invested Assets consist of investments our Company made in certain strategic companies which are accounted for using the equity method of accounting and overseas deposits which are carried at fair value. For our investments applying the equity method, these investments are initially recorded at cost and are subsequently adjusted based on our Company’s proportionate share of the net income or loss of the companies. Changes in the carrying value of such investments are recorded in Other Income. In applying the equity method, we use the most recently available financial information provided by the companies which is generally three months prior to the end of the reporting period. Overseas deposits include private funds held by the Syndicate and invested according to local regulatory requirements. The compositions of the overseas deposits vary and the deposits are based on the portfolio level reporting that is provided by Lloyd’s. The fair values of these overseas deposits were measured using the net asset value practical expedient and therefore have not been categorized within the fair value hierarchy. Changes in the fair value of the overseas deposits are recorded in Net Investment Income. Short-Term Investments are carried at fair value. Short-Term Investments have maturities greater than three months but less than one year from the purchase date. All prices for our Fixed Maturities, Equity Securities and Short-Term Investments are classified as Level 1, Level 2 or Level 3 under the fair value hierarchy, as defined in the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification 820 (“ASC 820”). Premiums and discounts on Fixed Maturities are amortized into interest income over the life of the security using the interest method. For Mortgage-Backed and Asset-Backed Securities, anticipated prepayments and expected maturities are utilized in applying the interest rate method. An effective yield is calculated based on projected principal cash flows at the time of original purchase. The effective yield is used to amortize the purchase price of the security over the security’s expected life. Book values are adjusted to reflect the amortization of premium or accretion of discount on a monthly basis. The projected principal cash flows are based on certain prepayment assumptions, which are generated using a prepayment model. The prepayment model uses a number of factors to estimate prepayment activity including the current levels of interest rates (refinancing incentive), time of year (seasonality), economic activity (including housing turnover) and term and age of the underlying collateral (burnout, seasoning). Prepayment assumptions associated with the Mortgage-Backed and Asset-Backed Securities are reviewed on a periodic basis. When changes in prepayment assumptions are deemed necessary as the result of actual prepayments differing from anticipated prepayments, securities are revalued based upon the new prepayment assumptions utilizing the retrospective adjustment method, whereby the effective yield is recalculated to reflect actual payments to date and anticipated future payments. The investment in such securities is adjusted to the amount that would have existed had the new effective yield been applied since the acquisition of the security. Such adjustments, if any, are included in Net Investment Income for the current period. Realized Gains and Losses on sales of investments are recognized when the related trades are executed and are determined on the basis of the specific identification method. Impairment of Invested Assets Management regularly reviews our Fixed Maturities portfolio to evaluate the necessity of recording impairment losses for other-than-temporary declines in the fair value of securities. Our Company reviews the magnitude of a security’s unrealized loss compared to its cost/amortized cost and the length of time that the security has been impaired to determine if an unrealized loss is other-than-temporary. If warranted as a result of conditions relating to a particular security, our Company will also review securities with declines in fair value resulting from a headline news event involving the issuer, a headline news event involving the asset class, the advice of our external asset managers, or economic events that may impact the issuer to determine if an unrealized loss is other-than-temporary. The depth of analysis performed is dependent upon the nature and magnitude of the indicators of other-than-temporary impairment present in regards to each impaired security. Our Company assesses the underlying fundamentals of each issuer to determine if there is a change in the amount or timing of expected cash flows. Management compares the amortized cost basis to the present value of the revised cash flows using the historical book yield to determine the credit loss portion of impairment which is recognized in earnings. All non-credit losses where we have the intent and ability to hold the security until recovery are recognized as changes in Other than Temporary Impairment (“OTTI”) losses within AOCI. Specifically for structured Fixed Maturities, our Company analyzes projections provided by our investment managers with respect to an expected principal loss under a range of scenarios and utilizes the most likely outcomes. The analysis relies on actual collateral performance measures such as default rate, prepayment rate and loss severity. These assumptions are applied throughout the remaining term of the deal, incorporating the transaction structure and priority of payments, to generate loss adjusted cash flows. Results of the analysis will indicate whether the security is expected ultimately to incur a loss or whether there is a material impact on yield due to either a projected loss or a change in cash flow timing. A break-even default rate is also calculated. A comparison of the break-even default rate to the actual default rate provides an indication of the level of cushion or coverage to the first dollar principal loss. For securities in which a tranche loss is present and the net present value of loss adjusted cash flows is less than book value, credit impairment is recognized in earnings. The output data also includes a number of additional metrics such as average life remaining, original and current credit support, over 60 day delinquency and security rating. The significant inputs used to measure the amount of credit loss recognized in earnings are actual delinquency rates, default probability, severity and prepayment assumptions. Projected losses are a function of both loss severity and probability of default, which differ based on property type, vintage and the stress of the collateral. For our policy on evaluating Equity Securities for impairment prior to the adoption of ASU 2016-01 on January 1, 2018, refer to Note 1 within our Annual Report on Form 10-K for the year ended December 31, 2017.

NOTE 1. ORGANIZATION & SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Unless the context requires otherwise, the terms “we,” “us,” “our” or “our Company” are used to mean The Navigators Group, Inc., a Delaware holding company established in 1982, and its subsidiaries. The term “Parent Company” is used to mean The Navigators Group, Inc. without its subsidiaries.

Organization

We are an international insurance company with a long-standing area of specialization in Marine insurance. We also offer Property and Casualty (“P&C”) insurance, primarily general liability coverage and umbrella & excess liability coverage to commercial enterprises through our Primary and Excess Casualty divisions. We have also developed niches in Professional Liability insurance, through our Directors & Officers (“D&O”) and Errors & Omissions (“E&O”) divisions, as well as assumed reinsurance products.

We operate through various wholly-owned insurance and service companies. Our subsidiaries domiciled in the United States (“U.S.”) include two insurance companies, Navigators Insurance Company (“NIC”) and Navigators Specialty Insurance Company (“NSIC”), as well as our U.S. underwriting agency, Navigators Management Company (“NMC”). NIC includes a branch in the United Kingdom (“U.K”). We also have operations domiciled in the U.K., Hong Kong and Europe. Navigators International Insurance Company Ltd. (“NIIC”), Navigators Management (U.K.) Ltd. (“NMUK”) and Navigators Underwriting Ltd. (“NUL”) are domiciled in the U.K. and NUL includes European branches. Navigators Underwriting Agency Ltd. (“NUAL”), a Lloyd’s of London (“Lloyd’s”) underwriting agency, manages and provides the capital, through Navigators Corporate Underwriters Ltd. (“NCUL”), for our Lloyd’s Syndicate 1221 (the “Syndicate”), and is also domiciled in the U.K. We control 100% of the Syndicate’s stamp capacity.

On June 7, 2018, we acquired 100% ownership interest in Bracht, Deckers & Mackelbert NV, an insurance underwriting agency organized under the laws of Belgium (“BDM”) and Assurances Continentales – Continentale Verzekeringen NV, an insurance company licensed under the laws of Belgium (“ASCO”). The acquisition was accounted for in accordance with Accounting Standards Codification (“ASC”) 805, “Business Combinations.” Refer to Note 2. Merger and Business Combinations and Note 6. Goodwill and Intangible Assets for further information regarding the acquisition.

On August 22, 2018, our Company entered into an Agreement and Plan of Merger (the “Merger Agreement”) with The Hartford Financial Services Group, Inc. (“The Hartford”). The Merger Agreement provides that, subject to the terms and conditions set forth therein, our Company will merge with an existing subsidiary of The Hartford, with our Company surviving as a wholly owned subsidiary of The Hartford (the “Merger”). Refer to Note 2. Merger and Business Combinations for further information.

Basis of Presentation

The Consolidated Balance Sheet at September 30, 2018 and the Consolidated Statements of Income (Loss), Comprehensive Income (Loss), Stockholders’ Equity and Cash Flows for the periods ended September 30, 2018 and 2017 are unaudited. The Balance Sheet at December 31, 2017 is derived from our audited Financial Statements. The accompanying Interim Consolidated Financial Statements reflect all adjustments, which, in the opinion of management, are necessary to fairly present the results of our Company for the interim periods presented on the basis of U.S. generally accepted accounting principles (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X as promulgated by the U.S. Securities and Exchange Commission. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. All significant intercompany transactions and balances have been eliminated in consolidation. The preparation of these Financial Statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the Financial Statements and the reported revenues and expenses during the reporting periods. The results of operations for any interim period are not necessarily indicative of results for the full year. The Interim Consolidated Financial Statements should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2017. Certain amounts for the prior period have been reclassified to conform with the current period presentation.

Income Taxes

On December 22, 2017, the Tax Cuts and Jobs Act (the “Tax Act”) was enacted into law and the new legislation contained several key tax provisions that affected us, including a one-time mandatory Deemed Repatriation Transition Tax (the “Transition Tax”) on accumulated foreign earnings and a reduction of the corporate income tax rate to 21% effective January 1, 2018, among others. We were required to recognize the effect of the tax law changes in the period of enactment, such as determining the Transition Tax, re-measuring our U.S. deferred tax assets and liabilities as well as reassessing the net realizability of our deferred tax assets and liabilities. In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118 (“SAB 118”), Income Tax Accounting Implications of the Tax Act, which allowed us to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. During the fourth quarter of 2017, we made a reasonable estimate of the effects on our deferred tax balances and recognized provisional tax amounts of $2.6 million related to the Transition Tax. As of September 30, 2018, we have finalized the calculation of the Transition Tax which resulted in a decrease in the provisional amount of $1.3 million and has been reflected as a discrete item in our Effective Tax Rate calculation. We will continue to evaluate the estimated effects on our deferred tax balances during the measurement period.

The interim income tax provision has been computed based on our estimated annual Effective Tax Rate, which represents our best estimate on a year to date basis for the interim period. As a result, the tax provision for a given quarter equals the difference between the provision recorded cumulatively year to date less the amount recorded cumulatively as of the end of the prior interim period. Our Effective Tax Rate for the quarter differs from the federal tax rate of 21% primarily due to tax-exempt investment income, the dividends received deduction, Transition Tax benefit, and an excess tax benefit related to the vesting of stock compensation at fair market value.

Short-Term Investments Reclassifications

Cash and overseas deposits that were misclassified within Short-Term Investments were reclassified representing an immaterial correction. Cash of $20.5 million as of December 31, 2017 was reclassified from Short-Term Investments to Cash and Cash Equivalents. Overseas deposits of $28.8 million as of December 31, 2017 were reclassified from Short-Term Investments to Other Invested Assets. The reclassification of cash within Short-Term Investments to Cash and Cash Equivalents impacted the Statement of Cash Flows for the nine months ended September 30, 2017 by decreasing Net Cash Used in Investing Activities by $9.2 million.

New Accounting Standards Adopted in 2018

Revenue From Contracts With Customers

Effective January 1, 2018, our Company adopted ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)”. This guidance affects any contracts with customers to transfer goods or services or for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (for example, insurance contracts are not in scope of the new guidance). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Our Company generates an insignificant amount of fee income that is within the scope of this guidance and was not materially impacted by the adoption of this guidance. The adoption of this guidance did not have a material impact on our results of operations, financial condition or liquidity.

Classification and Measurement of Financial Instruments

Effective January 1, 2018, our Company adopted ASU 2016-01 “Financial Instruments – Overall (Subtopic 825-10) – Recognition and Measurement of Financial Assets and Financial Liabilities”. This guidance requires equity investments (except those accounted for under the equity method of accounting, investments that are consolidated or those that meet a practicability exception) to be measured at fair value with changes in fair value recognized in net income, simplifies the impairment assessment of equity investments without readily determinable values by requiring a qualitative assessment to identify impairment, eliminates the requirement to disclose the methods and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost, requires the use of the exit price notion when measuring the fair value of financial instruments for disclosure purposes, requires separate presentation in other comprehensive income of the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the organization has elected to measure the liabilities in accordance with the fair value option, requires the separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or the accompanying notes to the financial statements and clarifies that the reporting organization should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the organization’s other deferred tax assets.

As of January 1, 2018, the adoption of this guidance resulted in a $7.7 million net after-tax increase to Retained Earnings with a corresponding decrease to Accumulated Other Comprehensive Income (Loss), resulting in no change to our Total Stockholders’ Equity. This adjustment reflects the cumulative effect adjustment to reclassify Net Unrealized Gain on Investments in Accumulated Other Comprehensive Income (Loss) for available-for-sale Equity Securities to Retained Earnings upon adoption. Upon the adoption of this guidance, Equity Securities have been measured at fair value with changes in fair value recognized in Net Income through Net Unrealized Gains (Losses) on Equity Securities. The other aspects of this guidance only impacted disclosure or did not apply to our Company and therefore did not impact our results of operations, financial condition or liquidity.

Cash Flows

Effective January 1, 2018, our Company adopted ASU 2016-15, “Statement of Cash Flows (Topic 230) – Classification of Certain Cash Receipts and Cash Payments” which addresses diversity in practice in how eight specific cash receipts and cash payments should be presented and classified on the statement of cash flows. The adoption of this guidance did not impact our results of operations, financial condition or liquidity.

Effective January 1, 2018, our Company adopted ASU 2016-18, “Statement of Cash Flows (Topic 230) – Restricted Cash” which addresses diversity in practice in the classification and presentation of changes in restricted cash on the statement of cash flows. This guidance requires a statement of cash flows to explain the change during the period in the total of cash, cash equivalents, restricted cash and restricted cash equivalents. Transfers between cash and cash equivalents and restricted cash and restricted cash equivalents will no longer be presented on the statement of cash flows. To assist in meeting the requirements of this guidance to provide a reconciliation from the Statement of Cash Flows to the Balance Sheet, upon adoption of this guidance our Company added new accounts titled “Cash and Cash Equivalents” and “Restricted Cash and Cash Equivalents” and reclassified amounts previously held in Short-Term Investments to these accounts for all periods presented. This resulted in the reclassification of $71.3 million of restricted and unrestricted cash and cash equivalent balances as of December 31, 2017. This guidance was adopted on a retrospective basis. Prior to the adoption of this guidance, restricted and unrestricted cash and cash equivalent balances included in the Short-Term Investments account had been presented as a cash flow provided by (used in) investing activities. Consequently, the Statement of Cash Flows for the nine months ended September 30, 2017 includes a revision to decrease “Net Cash Used in Investing Activities” by $76.8 million.

Income Taxes

Effective January 1, 2018, our Company adopted ASU 2016-16, “Income Taxes (Topic 740) – Intra-Entity Transfers of Assets Other than Inventory” that requires companies to account for the income tax effects of intercompany transfers of assets other than inventory when the transfer occurs. The adoption of this guidance did not impact our results of operations, financial condition or liquidity.

Definition of a Business

Effective January 1, 2018, our Company adopted ASU 2017-01, “Clarifying the Definition of a Business” that provides guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. This guidance will be applied to transactions prospectively. The adoption of this guidance did not impact our results of operations, financial condition or liquidity.

Tax Reform Reclassification from Other Comprehensive Income

Effective January 1, 2018, our Company early adopted ASU 2018-02, “Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income” that permits entities to reclassify tax effects stranded in accumulated other comprehensive income as a result of tax reform to retained earnings. The total impact of the remeasurement and other adjustments was reflected in 2017 income from continuing operations, regardless of where deferred taxes were originally recorded. As of January 1, 2018, the adoption of this guidance resulted in a one-time reclassification of $2.8 million, decreasing Retained Earnings and increasing Accumulated Other Comprehensive Income (Loss) primarily from the remeasurement of deferred tax assets and liabilities associated with unrealized gains and losses on investments and currency translation adjustments using the 21% corporate tax rate.

Recently Issued Accounting Standards Not Yet Adopted

Fair Value Measurement Disclosure

In August 2018, the FASB issued ASU 2018-13, “Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement”, which eliminates, adds, and modifies certain disclosure requirements for fair value measurements. The guidance eliminates the requirement to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for the timing of transfers between levels of the fair value hierarchy, and the valuation processes for Level 3 fair value measurements. The guidance adds the requirement to disclose changes in unrealized gains and losses included in other comprehensive income for the period and to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. The guidance modifies disclosures around the use of the practical expedient to measure the fair value of certain investments at their net asset values and modifies the requirement to disclose information as of the reporting date about the measurement uncertainty of Level 3 fair value measurement. This guidance is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted for the entire standard or only the provisions that eliminate or modify requirements. This guidance will be adopted on a prospective and retrospective basis, where applicable and as required. As this new guidance is disclosure-related only, adoption will not impact our results of operations, financial condition or liquidity.

Implementation Costs in a Cloud Computing Arrangement

In August 2018, the FASB issued ASU 2018-15, “Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract”, which requires companies to follow the internal-use software guidance in ASC 350-40 (Intangibles - Goodwill and Other - Internal-Use Software) to determine which implementation costs to capitalize as an asset and which costs to expense. Capitalized implementation costs will be amortized over the term of the service arrangement, beginning when the service arrangement or a component of the arrangement is ready for its intended use. This guidance is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted. This guidance will be applied prospectively. The adoption of this guidance is not expected to materially impact our results of operations, financial condition or liquidity.

Significant Accounting Policies

There were no notable changes in our significant accounting policies subsequent to our Annual Report on Form 10-K for the year ended December 31, 2017, with the exception of changes related to the adoption of ASU 2016-01 and ASU 2016-18 impacting the following accounting policies:

Cash and Cash Equivalents and Restricted Cash and Cash Equivalents

Cash includes cash on hand and demand deposits with banks. Cash Equivalents include highly liquid investments with original maturities of three months or less including money-market funds. Restricted Cash and Cash Equivalents primarily relates to funds that are held to support regulatory and contractual obligations.

Investments

Fixed Maturities held by our Company were carried at fair value and classified as available-for-sale. Available-for-sale securities are debt securities not classified as either held-to-maturity securities or trading securities and are reported at fair value, with unrealized gains and losses excluded from earnings and reported in Accumulated Other Comprehensive Income (“AOCI”) as a separate component of Stockholders’ Equity. Fixed Maturities include bonds, mortgage-backed and asset-backed securities, and redeemable preferred stocks.

Upon adoption of ASU 2016-01 on January 1, 2018, Equity Securities held by our Company were carried at fair value with any changes in fair value recognized in Net Income through the Net Unrealized Gains (Losses) on Equity Securities account. Prior to the adoption of ASU 2016-01, Equity Securities were carried at fair value and classified as available-for-sale. For our policy on Equity Securities classified as available-for-sale, refer to Note 1 within our Annual Report on Form 10-K for the year ended December 31, 2017. Equity Securities consist of common stock, exchange traded funds, mutual funds and preferred stock.

Other Invested Assets consist of investments our Company made in certain strategic companies which are accounted for using the equity method of accounting and overseas deposits which are carried at fair value.

For our investments applying the equity method, these investments are initially recorded at cost and are subsequently adjusted based on our Company’s proportionate share of the net income or loss of the companies. Changes in the carrying value of such investments are recorded in Other Income. In applying the equity method, we use the most recently available financial information provided by the companies which is generally three months prior to the end of the reporting period.

Overseas deposits include private funds held by the Syndicate and invested according to local regulatory requirements. The compositions of the overseas deposits vary and the deposits are based on the portfolio level reporting that is provided by Lloyd’s. The fair values of these overseas deposits were measured using the net asset value practical expedient and therefore have not been categorized within the fair value hierarchy. Changes in the fair value of the overseas deposits are recorded in Net Investment Income.

Short-Term Investments are carried at fair value. Short-Term Investments have maturities greater than three months but less than one year from the purchase date.

All prices for our Fixed Maturities, Equity Securities and Short-Term Investments are classified as Level 1, Level 2 or Level 3 under the fair value hierarchy, as defined in the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification 820 (“ASC 820”).

Premiums and discounts on Fixed Maturities are amortized into interest income over the life of the security using the interest method. For Mortgage-Backed and Asset-Backed Securities, anticipated prepayments and expected maturities are utilized in applying the interest rate method. An effective yield is calculated based on projected principal cash flows at the time of original purchase. The effective yield is used to amortize the purchase price of the security over the security’s expected life. Book values are adjusted to reflect the amortization of premium or accretion of discount on a monthly basis. The projected principal cash flows are based on certain prepayment assumptions, which are generated using a prepayment model. The prepayment model uses a number of factors to estimate prepayment activity including the current levels of interest rates (refinancing incentive), time of year (seasonality), economic activity (including housing turnover) and term and age of the underlying collateral (burnout, seasoning). Prepayment assumptions associated with the Mortgage-Backed and Asset-Backed Securities are reviewed on a periodic basis. When changes in prepayment assumptions are deemed necessary as the result of actual prepayments differing from anticipated prepayments, securities are revalued based upon the new prepayment assumptions utilizing the retrospective adjustment method, whereby the effective yield is recalculated to reflect actual payments to date and anticipated future payments. The investment in such securities is adjusted to the amount that would have existed had the new effective yield been applied since the acquisition of the security. Such adjustments, if any, are included in Net Investment Income for the current period.

Realized Gains and Losses on sales of investments are recognized when the related trades are executed and are determined on the basis of the specific identification method.

Impairment of Invested Assets

Management regularly reviews our Fixed Maturities portfolio to evaluate the necessity of recording impairment losses for other-than-temporary declines in the fair value of securities.

Our Company reviews the magnitude of a security’s unrealized loss compared to its cost/amortized cost and the length of time that the security has been impaired to determine if an unrealized loss is other-than-temporary. If warranted as a result of conditions relating to a particular security, our Company will also review securities with declines in fair value resulting from a headline news event involving the issuer, a headline news event involving the asset class, the advice of our external asset managers, or economic events that may impact the issuer to determine if an unrealized loss is other-than-temporary. The depth of analysis performed is dependent upon the nature and magnitude of the indicators of other-than-temporary impairment present in regards to each impaired security.

Our Company assesses the underlying fundamentals of each issuer to determine if there is a change in the amount or timing of expected cash flows. Management compares the amortized cost basis to the present value of the revised cash flows using the historical book yield to determine the credit loss portion of impairment which is recognized in earnings. All non-credit losses where we have the intent and ability to hold the security until recovery are recognized as changes in Other than Temporary Impairment (“OTTI”) losses within AOCI.

Specifically for structured Fixed Maturities, our Company analyzes projections provided by our investment managers with respect to an expected principal loss under a range of scenarios and utilizes the most likely outcomes. The analysis relies on actual collateral performance measures such as default rate, prepayment rate and loss severity. These assumptions are applied throughout the remaining term of the deal, incorporating the transaction structure and priority of payments, to generate loss adjusted cash flows. Results of the analysis will indicate whether the security is expected ultimately to incur a loss or whether there is a material impact on yield due to either a projected loss or a change in cash flow timing. A break-even default rate is also calculated. A comparison of the break-even default rate to the actual default rate provides an indication of the level of cushion or coverage to the first dollar principal loss. For securities in which a tranche loss is present and the net present value of loss adjusted cash flows is less than book value, credit impairment is recognized in earnings. The output data also includes a number of additional metrics such as average life remaining, original and current credit support, over 60 day delinquency and security rating. The significant inputs used to measure the amount of credit loss recognized in earnings are actual delinquency rates, default probability, severity and prepayment assumptions.

Projected losses are a function of both loss severity and probability of default, which differ based on property type, vintage and the stress of the collateral.

For our policy on evaluating Equity Securities for impairment prior to the adoption of ASU 2016-01 on January 1, 2018, refer to Note 1 within our Annual Report on Form 10-K for the year ended December 31, 2017.