Accounting Policies and Practices (Policies)	3 Months Ended
Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and should be read in conjunction with the Consolidated Financial Statements contained in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023, filed with the Securities and Exchange Commission (“SEC”) on February 29, 2024. In the opinion of management, all adjustments, including normal recurring adjustments, considered necessary for a fair presentation have been included. All intercompany transactions and balances have been eliminated upon consolidation. On July 2, 2021 (the “Closing Date”), Alight Holding Company, LLC (the "Predecessor" or "Alight Holdings") completed a business combination (the "Business Combination") with a special purpose acquisition company. On the Closing Date, pursuant to the Business Combination Agreement, the special purpose acquisition company became a wholly owned subsidiary of Alight, Inc. (“Alight”, the “Company”, “we” “us” “our” or the “Successor”). As of March 31, 2024, Alight owned approximately 99% of the economic interest in the Predecessor and had 100% of the voting power and controlled the management of the Predecessor. The non-voting ownership percentage held by noncontrolling interest was less than 1% as of March 31, 2024. On March 20, 2024, Alight, Inc. entered into a definitive agreement (the “Disposition Agreement”) to sell its Professional Services segment and its Payroll & HCM Outsourcing businesses within the Employer Solutions segment (“Payroll and Professional Services business”) for a purchase price of up to approximately $1.2 billion, in the form of $1 billion in cash and up to $200 million in seller notes, of which $150 million is contingent upon the Payroll & Professional Services business 2025 financial performance, subject to certain adjustments (the “Disposition”). As a result of this agreement, the results of the Company’s Payroll and Professional Services businesses are reported separately as discontinued operations, net of tax, in our condensed consolidated statements of comprehensive income (loss) for all periods presented and its assets and liabilities are presented in our condensed consolidated balance sheets as assets and liabilities held for sale. The transaction is expected to close by mid-year 2024, subject to customary closing conditions, including regulatory approvals. The Company's cash flows are presented inclusive of discontinued operations on the condensed consolidated statement of cash flows for all periods presented. The significant operating and investing non-cash components included in our condensed consolidated statement of cash flows for discontinued operations are included in Note 4.
Use of Estimates	Use of Estimates The preparation of the accompanying 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, disclosures of contingent assets and liabilities at the date of the financial statements, and the reported amounts of reserves and expenses. These estimates and assumptions are based on management’s best estimates and judgments. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment. Management believes its estimates to be reasonable given the current facts available. Management adjusts such estimates and assumptions when facts and circumstances dictate. Illiquid credit markets, volatile equity markets, and foreign currency exchange rate movements increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be predicted with certainty, actual results could differ significantly from these estimates. Changes in estimates resulting from continuing changes in the economic environment would, if applicable, be reflected in the financial statements in future periods.
New Accounting Pronouncements Not Yet Adopted	New Accounting Pronouncements Not Yet Adopted In November 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (ASU 2023-07), which requires an enhanced disclosure of significant segment expenses on an annual and interim basis. This guidance will be effective for the annual periods beginning the year ended December 31, 2024, and for interim periods beginning January 1, 2025. Early adoption is permitted. Upon adoption, the guidance should be applied retrospectively to all prior periods presented in the financial statements. The Company is currently evaluating the standard to determine the impact of adoption to its condensed consolidated financial statements and disclosures. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (ASU 2023-09), which improves the transparency of income tax disclosures by requiring consistent categories and greater disaggregation of information in the effective tax rate reconciliation and income taxes paid disaggregated by jurisdiction. It also includes certain other amendments to improve the effectiveness of income tax disclosures. This guidance will be effective for the annual periods beginning the year ended December 31, 2025. Early adoption is permitted. Upon adoption, the guidance can be applied prospectively or retrospectively. The Company is currently evaluating the standard to determine the impact of adoption to its condensed consolidated financial statements and disclosures.
Fair Value Measurement	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The accounting standards related to fair value measurements include a hierarchy for information and valuations used in measuring fair value that is broken down into three levels based on reliability, as follows: • Level 1 – observable inputs such as quoted prices in active markets for identical assets and liabilities; • Level 2 – inputs other than quoted prices for identical assets in active markets that are observable either directly or indirectly; and • Level 3 – unobservable inputs in which there is little or no market data which requires the use of valuation techniques and the development of assumptions.

Accounting Policies and Practices (Policies)

3 Months Ended

Mar. 31, 2024

The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and should be read in conjunction with the Consolidated Financial Statements contained in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023, filed with the Securities and Exchange Commission (“SEC”) on February 29, 2024. In the opinion of management, all adjustments, including normal recurring adjustments, considered necessary for a fair presentation have been included. All intercompany transactions and balances have been eliminated upon consolidation.

On July 2, 2021 (the “Closing Date”), Alight Holding Company, LLC (the "Predecessor" or "Alight Holdings") completed a business combination (the "Business Combination") with a special purpose acquisition company. On the Closing Date, pursuant to the Business Combination Agreement, the special purpose acquisition company became a wholly owned subsidiary of Alight, Inc. (“Alight”, the “Company”, “we” “us” “our” or the “Successor”). As of March 31, 2024, Alight owned approximately 99% of the economic interest in the Predecessor and had 100% of the voting power and controlled the management of the Predecessor. The non-voting ownership percentage held by noncontrolling interest was less than 1% as of March 31, 2024.

On March 20, 2024, Alight, Inc. entered into a definitive agreement (the “Disposition Agreement”) to sell its Professional Services segment and its Payroll & HCM Outsourcing businesses within the Employer Solutions segment (“Payroll and Professional Services business”) for a purchase price of up to approximately $1.2 billion, in the form of $1 billion in cash and up to $200 million in seller notes, of which $150 million is contingent upon the Payroll & Professional Services business 2025 financial performance, subject to certain adjustments (the “Disposition”). As a result of this agreement, the results of the Company’s Payroll and Professional Services businesses are reported separately as discontinued operations, net of tax, in our condensed consolidated statements of comprehensive income (loss) for all periods presented and its assets and liabilities are presented in our condensed consolidated balance sheets as assets and liabilities held for sale. The transaction is expected to close by mid-year 2024, subject to customary closing conditions, including regulatory approvals.

The Company's cash flows are presented inclusive of discontinued operations on the condensed consolidated statement of cash flows for all periods presented. The significant operating and investing non-cash components included in our condensed consolidated statement of cash flows for discontinued operations are included in Note 4.

Use of Estimates

The preparation of the accompanying 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, disclosures of contingent assets and liabilities at the date of the financial statements, and the reported amounts of reserves and expenses.

These estimates and assumptions are based on management’s best estimates and judgments. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment. Management believes its estimates to be reasonable given the current facts available. Management adjusts such estimates and assumptions when facts and circumstances dictate. Illiquid credit markets, volatile equity markets, and foreign currency exchange rate movements increase the uncertainty inherent in such estimates and assumptions. As future events and their effects cannot be predicted with certainty, actual results could differ significantly from these estimates. Changes in estimates resulting from continuing changes in the economic environment would, if applicable, be reflected in the financial statements in future periods.

New Accounting Pronouncements Not Yet Adopted

In November 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (ASU 2023-07), which requires an enhanced disclosure of significant segment expenses on an annual and interim basis. This guidance will be effective for the annual periods beginning the year ended December 31, 2024, and for interim periods beginning January 1, 2025. Early adoption is permitted. Upon adoption, the guidance should be applied retrospectively to all prior periods presented in the financial statements. The Company is currently evaluating the standard to determine the impact of adoption to its condensed consolidated financial statements and disclosures.

In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (ASU 2023-09), which improves the transparency of income tax disclosures by requiring consistent categories and greater disaggregation of information in the effective tax rate reconciliation and income taxes paid disaggregated by jurisdiction. It also includes certain other amendments to improve the effectiveness of income tax disclosures. This guidance will be effective for the annual periods beginning the year ended December 31, 2025. Early adoption is permitted. Upon adoption, the guidance can be applied prospectively or retrospectively. The Company is currently evaluating the standard to determine the impact of adoption to its condensed consolidated financial statements and disclosures.

Fair Value Measurement

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The accounting standards related to fair value measurements include a hierarchy for information and valuations used in measuring fair value that is broken down into three levels based on reliability, as follows:

•

Level 1 – observable inputs such as quoted prices in active markets for identical assets and liabilities;

•

Level 2 – inputs other than quoted prices for identical assets in active markets that are observable either directly or indirectly; and

•

Level 3 – unobservable inputs in which there is little or no market data which requires the use of valuation techniques and the development of assumptions.