Subsequent events	9 Months Ended
Sep. 30, 2026
Subsequent Events [Abstract]
Subsequent events	Subsequent events Acquisition of National Motor Club and Specialized Association Services On October 2, 2026, SiriusPoint, through its wholly owned subsidiaries, acquired National Motor Club and Specialized Association Services for $15.4 million. Legacy Reinsurance Loss Portfolio Transfer On October 30, 2026, SiriusPoint America Insurance Company ("SiriusPoint America") and SiriusPoint Bermuda Insurance Company Ltd. ("SiriusPoint Bermuda" and, together with SiriusPoint America, the "Cedents"), each a subsidiary of SiriusPoint Ltd., entered into a Master Agreement (the "Master Agreement"). The Master Agreement is made by and between the Cedents and RiverStone International Bermuda Limited ("RiverStone Bermuda"), an insurer domiciled in Bermuda, and Riverstone International Limited. Pursuant to the Master Agreement, at the closing of the transactions contemplated therein: (a) the Cedents and RiverStone Bermuda will enter into a Loss Portfolio Transfer Reinsurance and Retrocession Agreement (the "LPT Agreement"), under which the Cedents will cede and RiverStone Bermuda will assume up to 100% of the net reserves with respect to certain legacy reinsurance and retrocession exposures of the Cedents (the "Subject Business"), subject to the terms and conditions of the LPT Agreement, including an aggregate limit; (b) RiverStone International Insurance, Inc., an affiliate of RiverStone Bermuda (the "Administrator"), will assume authority and responsibility for certain administrative services related to the Subject Business, pursuant to the terms of the LPT Agreement; and (c) each of the Cedents, RiverStone Bermuda, and a trustee will enter into trust agreements under which RiverStone Bermuda will provide collateral securing its reinsurance obligations with respect to the Subject Business. The Subject Business includes substantially all of the Company’s remaining run-off reserves. This transaction covers approximately $400.0 million of SiriusPoint net loss and loss adjustment expense reserves, valued as of June 30, 2026. The aggregate limit under the LPT Agreement is $700.0 million. The Master Agreement and the LPT Agreement include customary representations and warranties, indemnification obligations, covenants and termination rights of the parties. The transaction is subject to regulatory approvals and customary closing conditions.

Subsequent events

9 Months Ended

Sep. 30, 2026

Acquisition of National Motor Club and Specialized Association Services

On October 2, 2026, SiriusPoint, through its wholly owned subsidiaries, acquired National Motor Club and Specialized Association Services for $15.4 million.

Legacy Reinsurance Loss Portfolio Transfer

On October 30, 2026, SiriusPoint America Insurance Company ("SiriusPoint America") and SiriusPoint Bermuda Insurance Company Ltd. ("SiriusPoint Bermuda" and, together with SiriusPoint America, the "Cedents"), each a subsidiary of SiriusPoint Ltd., entered into a Master Agreement (the "Master Agreement"). The Master Agreement is made by and between the Cedents and RiverStone International Bermuda Limited ("RiverStone Bermuda"), an insurer domiciled in Bermuda, and Riverstone International Limited.

Pursuant to the Master Agreement, at the closing of the transactions contemplated therein: (a) the Cedents and RiverStone Bermuda will enter into a Loss Portfolio Transfer Reinsurance and Retrocession Agreement (the "LPT Agreement"), under which the Cedents will cede and RiverStone Bermuda will assume up to 100% of the net reserves with respect to certain legacy reinsurance and retrocession exposures of the Cedents (the "Subject Business"), subject to the terms and conditions of the LPT Agreement, including an aggregate limit; (b) RiverStone International Insurance, Inc., an affiliate of RiverStone Bermuda (the "Administrator"), will assume authority and responsibility for certain administrative services related to the Subject Business, pursuant to the terms of the LPT Agreement; and (c) each of the Cedents, RiverStone Bermuda, and a trustee will enter into trust agreements under which RiverStone Bermuda will provide collateral securing its reinsurance obligations with respect to the Subject Business. The Subject Business includes substantially all of the Company’s remaining run-off reserves.

This transaction covers approximately $400.0 million of SiriusPoint net loss and loss adjustment expense reserves, valued as of June 30, 2026. The aggregate limit under the LPT Agreement is $700.0 million.

The Master Agreement and the LPT Agreement include customary representations and warranties, indemnification obligations, covenants and termination rights of the parties. The transaction is subject to regulatory approvals and customary closing conditions.