SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The accompanying condensed consolidated financial statements include the accounts of System1, Inc. and its subsidiaries for the Successor periods, and S1 Holdco for the Predecessor period. All intercompany accounts and transactions have been eliminated in the consolidation of the financial statements. The condensed consolidated financial statements have been prepared by the Company and are unaudited, pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such SEC rules and regulations. The interim condensed consolidated financial statements included herein reflect all adjustments (consisting of normal recurring adjustments) which are, in the opinion of management, necessary for a fair statement of the financial position, results of operations and cash flows for the interim periods presented. The condensed consolidated statements of operations for the three months ended March 31, 2023 (Successor), the period from January 1, 2022 through January 26, 2022 (Predecessor) and for the period from January 27, 2022 through March 31, 2022 (Successor) are not necessarily indicative of the results to be anticipated for the entire year ending December 31, 2023 or thereafter.
Principles of Consolidation	The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The accompanying condensed consolidated financial statements include the accounts of System1, Inc. and its subsidiaries for the Successor periods, and S1 Holdco for the Predecessor period. All intercompany accounts and transactions have been eliminated in the consolidation of the financial statements. The condensed consolidated financial statements have been prepared by the Company and are unaudited, pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such SEC rules and regulations. The interim condensed consolidated financial statements included herein reflect all adjustments (consisting of normal recurring adjustments) which are, in the opinion of management, necessary for a fair statement of the financial position, results of operations and cash flows for the interim periods presented. The condensed consolidated statements of operations for the three months ended March 31, 2023 (Successor), the period from January 1, 2022 through January 26, 2022 (Predecessor) and for the period from January 27, 2022 through March 31, 2022 (Successor) are not necessarily indicative of the results to be anticipated for the entire year ending December 31, 2023 or thereafter.
Adoption of Recent Accounting Pronouncements	Adoption of Recent Accounting Pronouncements On January 1, 2023, the Company adopted ASU No. 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Loss on Financial Instruments". Accordingly, upon adoption of this new standard, the Company recorded an allowance for credit losses of $327, with a corresponding cumulative adjustment to the beginning balance of accumulated deficit in the first quarter of fiscal 2023.
Use of Estimates	Use of Estimates The preparation of these 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, disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the reported amounts of revenue and expenses during the reporting period. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to: (1) valuation of goodwill, acquired intangible assets and long-lived assets, (2) valuation and recognition of the Company's stock-based compensation awards, and (3) income taxes. Significant estimates affecting the condensed consolidated financial statements have been prepared on the basis of the most current and best available information, including historical experience, known trends and other market-specific or other relevant factors that the Company believes to be reasonable. Management evaluates its estimates, as there are changes in circumstances, facts and experience. Changes in estimates are recorded in periods which they become known. However, actual results from the resolution of such estimates and assumptions may vary from those used in the preparation of the condensed consolidated financial statements.
Concentration of Credit Risk	Concentration of Credit Risk Cash is deposited with high-credit-quality financial institutions and, at times, such balances with any one financial institution may exceed the insurance limits of the prevailing regulatory body. Historically, the Company has not experienced any losses related to these cash balances and believes that there is minimal risk of expected future losses. However, there can be no assurance that there will not be losses on these deposits.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

3 Months Ended

Mar. 31, 2023

The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The accompanying condensed consolidated financial statements include the accounts of System1, Inc. and its subsidiaries for the Successor periods, and S1 Holdco for the Predecessor period. All intercompany accounts and transactions have been eliminated in the consolidation of the financial statements. The condensed consolidated financial statements have been prepared by the Company and are unaudited, pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such SEC rules and regulations. The interim condensed consolidated financial statements included herein reflect all adjustments (consisting of normal recurring adjustments) which are, in the opinion of management, necessary for a fair statement of the financial position, results of operations and cash flows for the interim periods presented. The condensed consolidated statements of operations for the three months ended March 31, 2023 (Successor), the period from January 1, 2022 through January 26, 2022 (Predecessor) and for the period from January 27, 2022 through March 31, 2022 (Successor) are not necessarily indicative of the results to be anticipated for the entire year ending December 31, 2023 or thereafter.

Principles of Consolidation

Adoption of Recent Accounting Pronouncements

Adoption of Recent Accounting Pronouncements On January 1, 2023, the Company adopted ASU No. 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Loss on Financial Instruments". Accordingly, upon adoption of this new standard, the Company recorded an allowance for credit losses of $327, with a corresponding cumulative adjustment to the beginning balance of accumulated deficit in the first quarter of fiscal 2023.

Use of Estimates

The preparation of these 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, disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the reported amounts of revenue and expenses during the reporting period.

Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to: (1) valuation of goodwill, acquired intangible assets and long-lived assets, (2) valuation and recognition of the Company's stock-based compensation awards, and (3) income taxes. Significant estimates affecting the condensed consolidated financial statements have been prepared on the basis of the most current and best available information, including historical experience, known trends and other market-specific or other relevant factors that the Company believes to be reasonable. Management evaluates its estimates, as there are changes in circumstances, facts and experience. Changes in estimates are recorded in periods which they become known. However, actual results from the resolution of such estimates and assumptions may vary from those used in the preparation of the condensed consolidated financial statements.

Concentration of Credit Risk

Cash is deposited with high-credit-quality financial institutions and, at times, such balances with any one financial institution may exceed the insurance limits of the prevailing regulatory body. Historically, the Company has not experienced any losses related to these cash balances and believes that there is minimal risk of expected future losses. However, there can be no assurance that there will not be losses on these deposits.