Basis of Presentation and Significant Accounting Policies	3 Months Ended
Mar. 31, 2018
Basis of Presentation and Significant Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	A. Basis of Presentation and Significant Accounting Policies Unless we have indicated otherwise, or the context otherwise requires, references in this report to “Associated Capital Group, Inc.,” “AC Group,” “the Company,” “AC,” “we,” “us” and “our” or similar terms are to Associated Capital Group, Inc., its predecessors and its subsidiaries. The Spin-off and Related Transactions We are a Delaware corporation that provides alternative investment management, institutional research and underwriting services. In addition, we derive investment income/(loss) from proprietary trading of cash and other assets awaiting deployment in our operating businesses. On November 30, 2015, GAMCO Investors, Inc. (“GAMCO” or “GBL”) distributed all the outstanding shares of each class of AC common stock on a pro rata one-for-one basis to the holders of each class of GAMCO’s common stock (the “Spin-off”). We conduct our investment management business through Gabelli & Company Investment Advisers, Inc. (“GCIA” f/k/a Gabelli Securities, Inc.). GCIA and its wholly-owned subsidiary, Gabelli & Partners, LLC (“Gabelli & Partners”), collectively serve as general partners or investment managers to investment funds including limited partnerships and offshore companies (collectively, “Investment Partnerships”), and separate accounts. We primarily manage assets in equity event-driven value strategies, across a range of risk and event arbitrage portfolios. The business earns management and incentive fees from its advisory assets. Management fees are largely based on a percentage of assets under management. Incentive fees are based on the percentage of the investment returns of certain clients’ portfolios. GCIA is an investment adviser registered with the Securities and Exchange Commission under the Investment Advisers Act of 1940, as amended. We provide our institutional research and underwriting services through G.research, LLC (“G.research”) doing business as “Gabelli & Company”, an indirect wholly-owned subsidiary of the Company. G.research is a broker-dealer registered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and is regulated by the Financial Industry Regulatory Authority (“FINRA”). G.research's revenues are derived primarily from institutional research services. In connection with the Spin-off, GAMCO issued a promissory note (the “GAMCO Note”) to AC Group in the original principal amount of $250 million used to partially capitalize the Company. The GAMCO Note bears interest at 4% per annum and has a maturity date of November 30, 2020 with respect to its original principal amount. Interest on the GAMCO Note will accrue from the most recent date for which interest has been paid. Prior to November 30, 2019, at the election of GAMCO, payment of interest on the GAMCO Note may, in lieu of being paid in cash, be paid, in whole or in part, in kind (a “PIK Amount”). GAMCO will repay all PIK Amounts added to the outstanding principal amount of the GAMCO Note, in cash, on the fifth anniversary of the date on which each such PIK Amount was added to the outstanding principal amount of the GAMCO Note. GAMCO may prepay the GAMCO Note prior to maturity without penalty. AC has received principal repayments totaling $210 million on the GAMCO Note, of which $10 million was received during the three months ended March 31, 2018 leaving an outstanding principal balance of $40 million due on November 30, 2020. In addition, GCIA purchased 4,393,055 shares of GAMCO Class A common stock in exchange for a note in the principal amount of $150 million (the “GCIA Note”). In connection with the Spin-off, GAMCO contributed the GCIA Note to the Company. During the quarter ended December 31, 2017, AC forgave the outstanding principal and interest on the GCIA Note. Basis of Presentation The unaudited interim condensed consolidated financial statements of AC Group included herein have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all the information and footnotes required by GAAP in the United States for complete financial statements. In the opinion of management, the unaudited interim condensed consolidated financial statements reflect all adjustments, which are of a normal recurring nature, necessary for a fair presentation of financial position, results of operations and cash flows of the Company for the interim periods presented and are not necessarily indicative of a full year’s results. The interim condensed consolidated financial statements include the accounts of AC Group and its subsidiaries. All material intercompany transactions and balances have been eliminated. These interim condensed consolidated financial statements should be read in conjunction with our audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2017. Use of Estimates The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported on the condensed consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Recent Accounting Developments In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers, which supersedes the revenue recognition requirements in ASC Topic 605, Revenue Recognition, and most industry-specific guidance throughout the industry topics of the ASC. The core principle of the new ASU No. 2014-09 requires companies to recognize revenue from the transfer of goods or services to customers in amounts that reflect the consideration to which the company expects to be entitled in exchange for those goods or services. The new standard provides a five-step approach to be applied to all contracts with customers and also requires expanded disclosures about revenue recognition. The ASU is effective for annual reporting periods beginning after December 15, 2017, including interim periods and is either applied on a retrospective or modified retrospective basis. The Company has evaluated this guidance and has concluded that it has no material impact on its condensed consolidated financial statements other than expanded disclosure. The Company has adopted this ASU effective January 1, 2018. In January 2016, the FASB issued ASU 2016-01, Financial Instruments–Overall: Recognition and Measurement of Financial Assets and Financial Liabilities, which amends the guidance in GAAP on the classification and measurement of financial instruments. Although the ASU retains many current requirements, it significantly revises an entity’s accounting related to (1) the classification and measurement of investments in equity securities and (2) the presentation of certain fair value changes for financial liabilities measured at fair value. Under the new guidance, all equity investments in unconsolidated entities (other than those accounted for using the equity method of accounting) will generally be measured at fair value through earnings. In addition, available for sale (“AFS”) classification (changes in fair value reported in other comprehensive income) for equity securities with readily determinable fair values will no longer be available. The ASU also amends certain disclosure requirements associated with the fair value of financial instruments. For public companies, the new standard is effective for fiscal years and interim periods within those fiscal years beginning after December 15, 2017. The Company has adopted this ASU effective January 1, 2018 with no material impact on its condensed consolidated financial statements other than the reclassification of the cumulative unrealized gain on equity securities net of tax from other comprehensive income to retained earnings. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), which amends the guidance in GAAP for the accounting for leases. ASU 2016-02 requires a lessee to recognize assets and liabilities arising from most operating leases in the consolidated statement of financial position. ASU 2016-02 is effective beginning January 1, 2019. The Company is currently evaluating this guidance and the impact it will have on its condensed consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments, which adds and clarifies guidance on the classification of certain cash receipts and payments in the consolidated statements of cash flows. For public companies, the ASU is effective for annual reporting periods beginning after December 15, 2017, including interim periods within those annual reporting periods. The Company adopted this ASU effective January 1, 2018 with no material impact on its condensed consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other, to simplify the process used to test for impairment of goodwill. Under the new standard, an impairment loss must be recognized in an amount equal to the excess of the carrying amount of a reporting unit over its fair value, limited to the total amount of goodwill allocated to that reporting unit. For public companies, the ASU is effective for annual and any interim impairment tests for periods beginning after December 15, 2019. Early adoption was permitted for impairment tests that occur after January 1, 2017. The Company is currently evaluating this guidance and the impact it will have on its condensed consolidated financial statements. On May 10, 2017, the FASB issued ASU 2017-09, Compensation – Stock Compensation, which amends the scope of modification accounting for share-based payment arrangements. The ASU provides guidance on the types of changes to the terms or conditions of share-based payment awards to which an entity would be required to apply modification accounting under ASC 718. Specifically, an entity would not apply modification accounting if the fair value, vesting conditions, and classification of the awards are the same immediately before and after the modification. For all entities, the ASU is effective for annual reporting periods, including interim periods within those annual reporting periods, beginning after December 15, 2017. The Company has adopted this ASU effective January 1, 2018 with no material impact on its condensed consolidated financial statements. On December 22, 2017, the SEC issued SAB 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act, to address the application of ASC 740, Income Taxes, in the reporting period that includes December 22, 2017, the date legislation commonly referred to as the Tax Cuts and Jobs Act (the “Act”) was signed into law. In general, the SAB provides that a company should reflect the income tax impacts of the Act for which the accounting under ASC 740 is complete. If a company is unable to complete the required accounting as a result of incomplete information, preparation or analysis, however, it may record a reasonable estimate as a provisional amount. Additional provisions deal with situations in which no reasonable estimate can be determined. Changes to estimates determined during a measurement period up to one year from the date of enactment will be reflected as an adjustment to tax expense or benefit in the reporting period the amounts are determined. With the exception of the book/tax differences related to the Company’s investments in funds that are partnerships and/or passive foreign investment companies, the Company has completed its analysis. We believe that we are able to make a reasonable estimate of the tax impact related to funds and have included this in the prior year’s tax provision. As additional information is received from the underlying funds (e.g., Form K-1s are received that set out AC’s share of the funds’ taxable income), these estimates will be adjusted, most likely in the fourth quarter of 2018 following the filing of the Company’s 2017 consolidated income tax return. The SAB also provides requirements concerning financial statement disclosures about the material financial reporting impacts of the Act. In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, dealing with the accounting for the tax effects of components of other comprehensive income (OCI). As a result of the reduction of the U.S. federal corporate income tax rate under the Tax Cuts and Jobs Act, current accounting guidance requires the revaluation of deferred tax assets and liabilities, and the resulting tax expense or benefit is reflected in net income. If the deferred tax asset or liability related to a component of OCI (e.g., unrealized gain/(loss) on AFS equity securities), however, the tax effects of items within OCI no longer reflect the appropriate tax rate (referred to as stranded tax effects). This ASU permits the reclassification of the stranded tax effects from OCI to retained earnings. The guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption was permitted. We have adopted the ASU as of January 1, 2018 and reflected an increase to OCI and a decrease to retained earnings of approximately $1.5 million in the current period.

A. Basis of Presentation and Significant Accounting Policies

Unless we have indicated otherwise, or the context otherwise requires, references in this report to “Associated Capital Group, Inc.,” “AC Group,” “the Company,” “AC,” “we,” “us” and “our” or similar terms are to Associated Capital Group, Inc., its predecessors and its subsidiaries.

The Spin-off and Related Transactions

We are a Delaware corporation that provides alternative investment management, institutional research and underwriting services. In addition, we derive investment income/(loss) from proprietary trading of cash and other assets awaiting deployment in our operating businesses. On November 30, 2015, GAMCO Investors, Inc. (“GAMCO” or “GBL”) distributed all the outstanding shares of each class of AC common stock on a pro rata one-for-one basis to the holders of each class of GAMCO’s common stock (the “Spin-off”).

We conduct our investment management business through Gabelli & Company Investment Advisers, Inc. (“GCIA” f/k/a Gabelli Securities, Inc.). GCIA and its wholly-owned subsidiary, Gabelli & Partners, LLC (“Gabelli & Partners”), collectively serve as general partners or investment managers to investment funds including limited partnerships and offshore companies (collectively, “Investment Partnerships”), and separate accounts. We primarily manage assets in equity event-driven value strategies, across a range of risk and event arbitrage portfolios. The business earns management and incentive fees from its advisory assets. Management fees are largely based on a percentage of assets under management. Incentive fees are based on the percentage of the investment returns of certain clients’ portfolios. GCIA is an investment adviser registered with the Securities and Exchange Commission under the Investment Advisers Act of 1940, as amended.

We provide our institutional research and underwriting services through G.research, LLC (“G.research”) doing business as “Gabelli & Company”, an indirect wholly-owned subsidiary of the Company. G.research is a broker-dealer registered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and is regulated by the Financial Industry Regulatory Authority (“FINRA”). G.research's revenues are derived primarily from institutional research services.

In connection with the Spin-off, GAMCO issued a promissory note (the “GAMCO Note”) to AC Group in the original principal amount of $250 million used to partially capitalize the Company. The GAMCO Note bears interest at 4% per annum and has a maturity date of November 30, 2020 with respect to its original principal amount. Interest on the GAMCO Note will accrue from the most recent date for which interest has been paid. Prior to November 30, 2019, at the election of GAMCO, payment of interest on the GAMCO Note may, in lieu of being paid in cash, be paid, in whole or in part, in kind (a “PIK Amount”). GAMCO will repay all PIK Amounts added to the outstanding principal amount of the GAMCO Note, in cash, on the fifth anniversary of the date on which each such PIK Amount was added to the outstanding principal amount of the GAMCO Note. GAMCO may prepay the GAMCO Note prior to maturity without penalty.

AC has received principal repayments totaling $210 million on the GAMCO Note, of which $10 million was received during the three months ended March 31, 2018 leaving an outstanding principal balance of $40 million due on November 30, 2020.

In addition, GCIA purchased 4,393,055 shares of GAMCO Class A common stock in exchange for a note in the principal amount of $150 million (the “GCIA Note”). In connection with the Spin-off, GAMCO contributed the GCIA Note to the Company. During the quarter ended December 31, 2017, AC forgave the outstanding principal and interest on the GCIA Note.

Basis of Presentation

The unaudited interim condensed consolidated financial statements of AC Group included herein have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all the information and footnotes required by GAAP in the United States for complete financial statements. In the opinion of management, the unaudited interim condensed consolidated financial statements reflect all adjustments, which are of a normal recurring nature, necessary for a fair presentation of financial position, results of operations and cash flows of the Company for the interim periods presented and are not necessarily indicative of a full year’s results.

The interim condensed consolidated financial statements include the accounts of AC Group and its subsidiaries. All material intercompany transactions and balances have been eliminated.

These interim condensed consolidated financial statements should be read in conjunction with our audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2017.

Use of Estimates

The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported on the condensed consolidated financial statements and accompanying notes. Actual results could differ from those estimates.

Recent Accounting Developments

In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers, which supersedes the revenue recognition requirements in ASC Topic 605, Revenue Recognition, and most industry-specific guidance throughout the industry topics of the ASC. The core principle of the new ASU No. 2014-09 requires companies to recognize revenue from the transfer of goods or services to customers in amounts that reflect the consideration to which the company expects to be entitled in exchange for those goods or services. The new standard provides a five-step approach to be applied to all contracts with customers and also requires expanded disclosures about revenue recognition. The ASU is effective for annual reporting periods beginning after December 15, 2017, including interim periods and is either applied on a retrospective or modified retrospective basis. The Company has evaluated this guidance and has concluded that it has no material impact on its condensed consolidated financial statements other than expanded disclosure. The Company has adopted this ASU effective January 1, 2018.

In January 2016, the FASB issued ASU 2016-01, Financial Instruments–Overall: Recognition and Measurement of Financial Assets and Financial Liabilities, which amends the guidance in GAAP on the classification and measurement of financial instruments. Although the ASU retains many current requirements, it significantly revises an entity’s accounting related to (1) the classification and measurement of investments in equity securities and (2) the presentation of certain fair value changes for financial liabilities measured at fair value. Under the new guidance, all equity investments in unconsolidated entities (other than those accounted for using the equity method of accounting) will generally be measured at fair value through earnings. In addition, available for sale (“AFS”) classification (changes in fair value reported in other comprehensive income) for equity securities with readily determinable fair values will no longer be available. The ASU also amends certain disclosure requirements associated with the fair value of financial instruments. For public companies, the new standard is effective for fiscal years and interim periods within those fiscal years beginning after December 15, 2017. The Company has adopted this ASU effective January 1, 2018 with no material impact on its condensed consolidated financial statements other than the reclassification of the cumulative unrealized gain on equity securities net of tax from other comprehensive income to retained earnings.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), which amends the guidance in GAAP for the accounting for leases. ASU 2016-02 requires a lessee to recognize assets and liabilities arising from most operating leases in the consolidated statement of financial position. ASU 2016-02 is effective beginning January 1, 2019. The Company is currently evaluating this guidance and the impact it will have on its condensed consolidated financial statements.

In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments, which adds and clarifies guidance on the classification of certain cash receipts and payments in the consolidated statements of cash flows. For public companies, the ASU is effective for annual reporting periods beginning after December 15, 2017, including interim periods within those annual reporting periods. The Company adopted this ASU effective January 1, 2018 with no material impact on its condensed consolidated financial statements.

In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other, to simplify the process used to test for impairment of goodwill. Under the new standard, an impairment loss must be recognized in an amount equal to the excess of the carrying amount of a reporting unit over its fair value, limited to the total amount of goodwill allocated to that reporting unit. For public companies, the ASU is effective for annual and any interim impairment tests for periods beginning after December 15, 2019. Early adoption was permitted for impairment tests that occur after January 1, 2017. The Company is currently evaluating this guidance and the impact it will have on its condensed consolidated financial statements.

On May 10, 2017, the FASB issued ASU 2017-09, Compensation – Stock Compensation, which amends the scope of modification accounting for share-based payment arrangements. The ASU provides guidance on the types of changes to the terms or conditions of share-based payment awards to which an entity would be required to apply modification accounting under ASC 718. Specifically, an entity would not apply modification accounting if the fair value, vesting conditions, and classification of the awards are the same immediately before and after the modification. For all entities, the ASU is effective for annual reporting periods, including interim periods within those annual reporting periods, beginning after December 15, 2017. The Company has adopted this ASU effective January 1, 2018 with no material impact on its condensed consolidated financial statements.

On December 22, 2017, the SEC issued SAB 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act, to address the application of ASC 740, Income Taxes, in the reporting period that includes December 22, 2017, the date legislation commonly referred to as the Tax Cuts and Jobs Act (the “Act”) was signed into law. In general, the SAB provides that a company should reflect the income tax impacts of the Act for which the accounting under ASC 740 is complete. If a company is unable to complete the required accounting as a result of incomplete information, preparation or analysis, however, it may record a reasonable estimate as a provisional amount. Additional provisions deal with situations in which no reasonable estimate can be determined. Changes to estimates determined during a measurement period up to one year from the date of enactment will be reflected as an adjustment to tax expense or benefit in the reporting period the amounts are determined. With the exception of the book/tax differences related to the Company’s investments in funds that are partnerships and/or passive foreign investment companies, the Company has completed its analysis. We believe that we are able to make a reasonable estimate of the tax impact related to funds and have included this in the prior year’s tax provision. As additional information is received from the underlying funds (e.g., Form K-1s are received that set out AC’s share of the funds’ taxable income), these estimates will be adjusted, most likely in the fourth quarter of 2018 following the filing of the Company’s 2017 consolidated income tax return. The SAB also provides requirements concerning financial statement disclosures about the material financial reporting impacts of the Act.

In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, dealing with the accounting for the tax effects of components of other comprehensive income (OCI). As a result of the reduction of the U.S. federal corporate income tax rate under the Tax Cuts and Jobs Act, current accounting guidance requires the revaluation of deferred tax assets and liabilities, and the resulting tax expense or benefit is reflected in net income. If the deferred tax asset or liability related to a component of OCI (e.g., unrealized gain/(loss) on AFS equity securities), however, the tax effects of items within OCI no longer reflect the appropriate tax rate (referred to as stranded tax effects). This ASU permits the reclassification of the stranded tax effects from OCI to retained earnings. The guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption was permitted. We have adopted the ASU as of January 1, 2018 and reflected an increase to OCI and a decrease to retained earnings of approximately $1.5 million in the current period.