Significant Accounting Policies	3 Months Ended
Mar. 31, 2020
Significant Accounting Policies [Abstract]
Significant Accounting Policies	1. Significant Accounting Policies Basis of Presentation The unaudited interim condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and pursuant to the requirements for reporting on Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all the information and footnotes required by U.S. GAAP 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 the fair presentation of financial position, results of operations, and cash flows of GAMCO 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 the Company and its wholly-owned subsidiaries: Gabelli Funds, GAMCO Asset, Distributors Holdings, Inc., G.distributors, GAMCO Asset Management (UK) Limited, Gabelli Fixed Income, Inc., Gabelli Fixed Income L.L.C., GAMCO International Partners LLC, and GAMCO Acquisition LLC. Intercompany accounts and transactions 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, 2019. Use of Estimates The preparation of the interim condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Recent Accounting Developments In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842) (“ASU 2016-02”), which amends the guidance in U.S. GAAP for the accounting for leases with terms longer than 12 months. ASU 2016-02 requires a lessee to recognize assets and liabilities arising from these leases in the consolidated statement of financial position. It requires these leases to be recorded on the balance sheet as right-of-use assets and offsetting lease liability obligations. The guidance was effective for the Company on January 1, 2019 and the Company adopted this guidance on that date. The Company has elected the transition method allowed under ASU 2018-11, Leases (Topic 842): Targeted Improvements, which does not require restatement of comparative periods, but instead requires a cumulative adjustment to opening retained earnings at the January 1, 2019 adoption date. The Company has performed the analysis on the transition to this guidance and, as a result, recorded a $106 thousand reduction to retained earnings, a $650 thousand increase to other assets, and a $756 thousand increase to lease liability obligations. In June 2016, the FASB issued ASU 2016-13, Accounting for Financial Instruments - Credit Losses (Topic 326) (“ASU 2016-13”), which requires an organization to measure all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. Currently, U.S. GAAP requires an “incurred loss” methodology that delays recognition until it is probable a loss has been incurred. Under ASU 2016-13, the allowance for credit losses must be deducted from the amortized cost of the financial asset to present the net amount expected to be collected. The consolidated statement of income will reflect the measurement of credit losses for newly recognized financial assets as well as the expected increases or decreases of expected credit losses that have taken place during the period. In November 2019, the FASB issued ASU 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), Leases (Topic 842): Effective Dates (ASU 2019-10), which deferred the effective date of this guidance for smaller reporting companies for three years. This guidance is effective for the Company on January 1, 2023 and requires a modified retrospective transition method, which will result in a cumulative-effect adjustment in retained earnings upon adoption. Early adoption is permitted. The Company is currently assessing the potential impact of this new guidance on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350) - Simplifying the Test for Goodwill Impairment (“ASU 2017-04”), which simplifies the process used to test for goodwill impairment by eliminating the requirement to calculate the implied fair value of goodwill, and instead any goodwill impairment will be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. In November 2019, the FASB issued ASU 2019-10, which deferred the effective date of this guidance for smaller reporting companies for three years. This guidance will be effective for the Company on January 1, 2023 using a prospective transition method and early adoption is permitted. The Company is currently evaluating the potential effect of this new guidance on the Company’s consolidated financial statements.

1. Significant Accounting Policies

Basis of Presentation

The unaudited interim condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and pursuant to the requirements for reporting on Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all the information and footnotes required by U.S. GAAP 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 the fair presentation of financial position, results of operations, and cash flows of GAMCO 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 the Company and its wholly-owned subsidiaries: Gabelli Funds, GAMCO Asset, Distributors Holdings, Inc., G.distributors, GAMCO Asset Management (UK) Limited, Gabelli Fixed Income, Inc., Gabelli Fixed Income L.L.C., GAMCO International Partners LLC, and GAMCO Acquisition LLC. Intercompany accounts and transactions 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, 2019.

Use of Estimates

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

Recent Accounting Developments

In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842) (“ASU 2016-02”), which amends the guidance in U.S. GAAP for the accounting for leases with terms longer than 12 months. ASU 2016-02 requires a lessee to recognize assets and liabilities arising from these leases in the consolidated statement of financial position. It requires these leases to be recorded on the balance sheet as right-of-use assets and offsetting lease liability obligations. The guidance was effective for the Company on January 1, 2019 and the Company adopted this guidance on that date. The Company has elected the transition method allowed under ASU 2018-11, Leases (Topic 842): Targeted Improvements, which does not require restatement of comparative periods, but instead requires a cumulative adjustment to opening retained earnings at the January 1, 2019 adoption date. The Company has performed the analysis on the transition to this guidance and, as a result, recorded a $106 thousand reduction to retained earnings, a $650 thousand increase to other assets, and a $756 thousand increase to lease liability obligations.

In June 2016, the FASB issued ASU 2016-13, Accounting for Financial Instruments - Credit Losses (Topic 326) (“ASU 2016-13”), which requires an organization to measure all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. Currently, U.S. GAAP requires an “incurred loss” methodology that delays recognition until it is probable a loss has been incurred. Under ASU 2016-13, the allowance for credit losses must be deducted from the amortized cost of the financial asset to present the net amount expected to be collected. The consolidated statement of income will reflect the measurement of credit losses for newly recognized financial assets as well as the expected increases or decreases of expected credit losses that have taken place during the period. In November 2019, the FASB issued ASU 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), Leases (Topic 842): Effective Dates (ASU 2019-10), which deferred the effective date of this guidance for smaller reporting companies for three years. This guidance is effective for the Company on January 1, 2023 and requires a modified retrospective transition method, which will result in a cumulative-effect adjustment in retained earnings upon adoption. Early adoption is permitted. The Company is currently assessing the potential impact of this new guidance on the Company’s consolidated financial statements.

In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350) - Simplifying the Test for Goodwill Impairment (“ASU 2017-04”), which simplifies the process used to test for goodwill impairment by eliminating the requirement to calculate the implied fair value of goodwill, and instead any goodwill impairment will be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. In November 2019, the FASB issued ASU 2019-10, which deferred the effective date of this guidance for smaller reporting companies for three years. This guidance will be effective for the Company on January 1, 2023 using a prospective transition method and early adoption is permitted. The Company is currently evaluating the potential effect of this new guidance on the Company’s consolidated financial statements.