Subsequent Events	9 Months Ended
Subsequent Events	Sep. 30, 2024
Subsequent Events [Abstract]
Subsequent Events	Note 22 – Subsequent Events Extension of Rithm Servicing Termination Rights On October 14, 2024, Onity and Rithm agreed to extend Rithm’s termination rights with respect to its subservicing agreements from October 1, 2024 through November 15, 2024. In addition, Onity and Rithm agreed to extend the current terms of the subservicing agreements through February 1, 2025. Onity and Rithm continue to discuss extending their current servicing arrangements. The subservicing UPB subject to termination rights on November 15, 2024 amounted to $32.9 billion as of September 30, 2024, and the related subservicing fees amounted to $34.6 million for the nine months ended September 30, 2024. Also refer to Note 20 — Commitments, Client Concentration. Oaktree Warrant Amendment On October 23, 2024, pursuant to the Transaction Agreement with Oaktree described in Note 11 - Investment in Equity Method Investee and Related Party Transactions, the warrants held by Oaktree were amended to provide that upon their exercise Oaktree can elect the cash exercise option only with the consent of Onity and, without the consent of Onity, the exercise price can only be paid via the net share settlement option. Previously, Oaktree had the option to pay the exercise price either in cash or via net share settlement. As of September 30, 2024, Oaktree holds 1,184,768 and 261,248 warrants to purchase shares of Onity’s common stock at an exercise price of $26.82 and $24.31 per share, respectively, subject to anti-dilution adjustments. The amendment will not result in any change in the accounting or presentation of the warrants. MAM Asset Acquisition and Financing, Preferred Stock Issuance On October 9, 2024, Onity and PHH entered into a definitive agreement with Mortgage Assets Management, LLC (MAM), a mortgage servicer, and certain investment funds managed by Waterfall Asset Management, LLC that own MAM (collectively “Waterfall”) to acquire certain assets of MAM and Waterfall that are currently subserviced by PHH with an estimated book value of $55.1 million, subject to certain post-closing adjustments (“MAM Asset Acquisition”). Onity had previously entered into a letter of intent with Waterfall on July 26, 2024 in connection with this transaction. The acquired assets include HECM reverse mortgage loans and mortgage servicing rights with a projected UPB of approximately $3.0 billion (which assets will be reflected on Onity’s balance sheet as Loans held for investment, at fair value along with the related borrowings, at fair value), $20 million in cash, and reverse mortgage buyouts, advances, tails and other related assets. In consideration of the MAM Asset Acquisition, Onity issued to Waterfall shares of a new series of non-convertible, perpetual preferred stock ("Series B Preferred Stock”) with an aggregate liquidation preference amount of $52.8 million, subject to certain post-closing adjustments. The Series B Preferred Stock will accrue cumulative dividends initially at a rate of 7.875% per year for the first five years, increasing 2.5% each year thereafter up to a maximum rate of 15% per year, which dividends will be payable in cash and in arrears on a quarterly basis when, as and if declared by the board of directors of Onity. After September 15, 2028, Onity will be able to redeem the Series B Preferred Stock, in whole or in part, for cash at a redemption price equal to the liquidation preference plus an amount equal to any accumulated and unpaid dividends thereon. If Onity experiences a change of control, as defined, it would be required to offer to repurchase all of the shares of Series B Preferred Stock at a purchase price equal to 100% of the liquidation preference plus an amount equal to any accumulated and unpaid dividends thereon. The issued shares of Series B Preferred Stock are subject to a Registration Rights Agreement pursuant to which Onity agreed to file a resale registration statement with the Securities and Exchange Commission within 180 days. The preferred stock will be accounted for at their initial fair value less issuance costs and classified as mezzanine equity on our consolidated balance sheet as it is contingently redeemable in the event of a change of control. Net income attributable to Onity common stockholders will be measured as Net income (attributable to Onity stockholders) less Preferred stock dividends. Concurrently, Onity entered into a Loan and Security Agreement with an entity managed by Waterfall pursuant to which PHH may borrow against certain eligible reverse mortgage assets, as defined, on a revolving basis for two years up to a maximum committed amount (“WAM Financing Agreement”). The maximum committed amount decreases from an initial $45 million to $15 million after the first securitization of HECM tails. The obligations of PHH under the Loan and Security Agreement are guaranteed by Onity. The consummation of the MAM Asset Acquisition, WAM Financing Agreement and Series B Preferred Stock issuance occurred on November 1, 2024. Due to the timing of the transaction, the fair value of the assets acquired and the preferred stock issued on November 1, 2024 has not yet been determined as of the date of issuance of these financial statements. Issuance of $500 million PHH Senior Notes due 2029 On November 6, 2024, Onity issued $500 million aggregate principal amount of 9.875% Senior Notes due 2029 at a price of 99.556% of the principal amount in a syndicated private placement to redeem all of the outstanding $289.1 million 7.875% PMC Senior Secured Notes due 2026 and $285.0 million 12% Onity Senior Secured Notes due 2027 subject to certain conditions described below. The PHH Senior Notes were issued by PHH Escrow Issuer LLC, a special purpose entity wholly-owned and consolidated by PHH Corporation and Onity. Oaktree was allocated $50 million of the PHH Senior Notes principal amount. The net proceeds from the sale of the PHH Senior Notes, together with approximately $23 million additional cash from Onity, are placed into escrow pending the satisfaction of certain conditions, including, but not limited to, the consummation of the sale by Onity of its 15% ownership interest in MAV to Oaktree, pursuant to the Transaction Agreement with Oaktree discussed in Note 11 - Investment in Equity Method Investee and Related Party Transactions. We expect to consummate the MAV sale during the fourth quarter of 2024, subject to regulatory approval and customary closing conditions. The total cash proceeds to be received by Onity upon consummation of the MAV Sale are currently expected to be approximately $49 million resulting in the recognition of a gain on sale of its investment of approximately $19 million (based on values as of September 30, 2024), excluding transaction costs. Upon completion of the MAV sale and satisfaction of all escrow conditions, the escrowed proceeds will be released to PHH Corporation as co-issuer and will be used, together with the net proceeds from the MAV sale and available liquidity, to redeem all of the outstanding PMC Senior Secured Notes due 2026 and all of the outstanding Onity Senior Secured Notes due 2027. The PHH Senior Notes will be guaranteed by Onity and certain subsidiaries. The redemption of all of the outstanding PMC Senior Secured Notes due 2026 and all of the outstanding Onity Senior Secured Notes due 2027 is currently expected to result in the recognition of an estimated $53 million loss on debt extinguishment due to the accelerated write-off of $37 million unamortized discount and debt issuance costs, the payment of an $12 million make-whole redemption premium and $5 million transaction fee to Oaktree. In addition, a total estimated $10 million of new debt issuance costs (underwriting, legal and other fees) will be amortized over the life of the PHH Senior Secured Notes due 2029.