Business and Basis of Presentation	3 Months Ended
Business and Basis of Presentation	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Basis of Presentation	1. Business and Basis of Presentation Description of the Business Compass, Inc. (the “Company”) was incorporated in Delaware on October 4, 2012 under the name Urban Compass, Inc. On January 8, 2021, the board of directors approved a change to the Company’s name from Urban Compass, Inc. to Compass, Inc. The Company provides an end-to-end platform that empowers its residential real estate agents to deliver exceptional service to seller and buyer clients. The Company’s platform includes an integrated suite of cloud-based software for customer relationship management, marketing, client service and other critical functionality, all custom-built for the real estate industry, which enables the Company’s core brokerage services. The platform also uses proprietary data, analytics, artificial intelligence, and machine learning to deliver high value recommendations and outcomes for Compass agents and their clients. The Company’s agents are independent contractors who affiliate their real estate licenses with the Company, operating their businesses on the Company’s platform and under the Compass brand. The Company generates revenue from clients through its agents by assisting home sellers and buyers in listing, marketing, selling and finding homes as well as through the provision of services adjacent to the transaction, like title and escrow services, which comprise a smaller portion of the Company’s revenue to date. The Company currently generates substantially all of its revenue from commissions paid by clients at the time that a home is transacted. Initial Public Offering On April 6, 2021, the Company completed its initial public offering (“IPO”) and the Company’s Class A common stock began trading on the New York Stock Exchange on April 1, 2021 under the symbol “COMP”. In connection with the IPO, the Company issued and sold 26,296,438 shares of its common stock at a public offering price of $18.00 per share. The Company received aggregate proceeds of $438.7 million from the IPO, net of the underwriting discount and offering costs of approximately $11.0 million (of which $0.9 million were paid in 2020). Offering costs, including the legal, accounting, printing and other IPO-related costs have been recorded in Additional paid-in capital against the proceeds from the offering. During April 2021, also in connection with the IPO, all series of the Company’s convertible preferred stock then outstanding were converted into 223,033,725 shares of common stock and the Company reclassified $1.4 billion of Convertible preferred stock to Additional paid-in-capital. On March 31, 2021, in connection with the effectiveness of the Company’s IPO registration statement, the Company recognized $148.5 million in stock-based compensation expense for (i) certain RSUs that contained both service-based and liquidity event-based vesting conditions as the liquidity event-based vesting condition was satisfied upon effectiveness of the registration statement and (ii) certain stock options and RSU awards with service, performance and market-based vesting conditions that include stock price targets to be met after the listing of the Company’s stock on a public exchange. Basis of Presentation The condensed consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The Company’s condensed consolidated financial statements were prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) and include the assets, liabilities, revenues and expenses of all controlled subsidiaries. The condensed consolidated statements of operations include the results of entities acquired from the date of each respective acquisition. Interests held by third parties in consolidated subsidiaries are presented as non-controlling interests, which represents the non-controlling stockholders’ interests in the underlying net assets of the Company’s consolidated subsidiaries. For entities where the Company does not have a controlling interest (financial or operating), the investments in such entities are accounted for using the equity method. The Company applies the equity method of accounting when it has the ability to exercise significant influence over the operating and financial policies of an investee. The Company measures all other investments at fair value with changes in fair value recognized in net income or in the case that an equity investment does not have readily determinable fair values, at cost minus impairment (if any) plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment. The unaudited interim condensed consolidated financial statements and related disclosures have been prepared by management on a basis consistent with the annual consolidated financial statements and, in the opinion of management, include all adjustments necessary for a fair statement of the interim periods presented. The results of the interim periods presented are not necessarily indicative of the results expected for the full year. Certain information and notes normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted under the SEC’s rules and regulations. Accordingly, the unaudited condensed consolidated financial statements and notes included herein should be read in conjunction with the Company’s audited consolidated financial statements and the related notes for the year ended December 31, 2021, included in the 2021 Form 10-K.