v3.26.1
Fair value measurements (Tables)
 6 Months Ended
Jun. 30, 2026
Fair Value Disclosures [Abstract]  
Schedule of Investments, Categorized by the Level of the Fair Value Hierarchy
The following tables present the Company’s investments measured and reported at fair value, categorized by the level of the fair value hierarchy as of June 30, 2026 and December 31, 2025:
June 30, 2026
 Quoted prices in active markets Significant other observable inputs Significant unobservable inputs Total
 (Level 1) (Level 2) (Level 3)
Assets
Asset-backed securities$— $842.9 $— $842.9 
Residential mortgage-backed securities— 960.0 — 960.0 
Commercial mortgage-backed securities— 256.1 — 256.1 
Corporate debt securities— 2,237.2 — 2,237.2 
U.S. government and government agency840.6 — — 840.6 
Non-U.S. government and government agency— 20.1 — 20.1 
Total debt securities, available for sale840.6 4,316.3 — 5,156.9 
Asset-backed securities— 5.1 — 5.1 
Residential mortgage-backed securities— 27.0 — 27.0 
Commercial mortgage-backed securities— 26.4 — 26.4 
Corporate debt securities— 3.4 — 3.4 
U.S. government and government agency2.9 — — 2.9 
Total debt securities, trading2.9 61.9 — 64.8 
Short-term investments7.5 — — 7.5 
Other long-term investments— — 57.5 57.5 
Derivative assets— — 6.2 6.2 
$851.0 $4,378.2 $63.7 5,292.9 
Cost and equity method investments60.9 
Investments in funds valued at NAV167.4 
Total assets$5,521.2 
Liabilities
Derivative liabilities $— $— $29.1 $29.1 
Total liabilities$— $— $29.1 $29.1 
December 31, 2025
 Quoted prices in active markets Significant other observable inputs Significant unobservable inputs Total
 (Level 1) (Level 2) (Level 3)
Assets
Asset-backed securities$— $921.1 $— $921.1 
Residential mortgage-backed securities— 963.1 — 963.1 
Commercial mortgage-backed securities— 231.9 — 231.9 
Corporate debt securities— 2,198.2 — 2,198.2 
U.S. government and government agency835.7 — — 835.7 
Non-U.S. government and government agency— 18.6 — 18.6 
Total debt securities, available for sale835.7 4,332.9 — 5,168.6 
Asset-backed securities— 5.9 — 5.9 
Residential mortgage-backed securities— 45.0 — 45.0 
Commercial mortgage-backed securities— 31.9 — 31.9 
Corporate debt securities— 3.7 — 3.7 
U.S. Government and government agency3.8 — — 3.8 
Total debt securities, trading3.8 86.5 — 90.3 
Short-term investments28.3 — — 28.3 
Other long-term investments— 5.2 82.9 88.1 
Derivative assets— — 14.4 14.4 
$867.8 $4,424.6 $97.3 5,389.7 
Cost and equity method investments69.3 
Investments in funds valued at NAV157.7 
Total assets$5,616.7 
Liabilities
Derivative liabilities$— $— $9.0 $9.0 
Total liabilities$— $— $9.0 $9.0 
Schedule of Reconciliation of Assets Measured at Fair Value using Level 3 Inputs
The following tables present the reconciliation of investments measured at fair value using Level 3 inputs for the three and six months ended June 30, 2026 and 2025:
April 1,
2026		Transfers in to (out of) Level 3PurchasesSales & Settlements
Realized and Unrealized Gains (Losses) (1)
June 30,
2026
Other long-term investments$63.7 $— $— $— $(6.2)$57.5 
Net derivatives (2)
$(31.7)$— $— $— $8.8 $(22.9)
January 1, 2026Transfers in to (out of) Level 3PurchasesSales & Settlements
Realized and Unrealized Gains(Losses) (1)
June 30,
2026
Other long-term investments$82.9 $— $— $(22.7)$(2.7)$57.5 
Net derivatives (2)
$5.4 $— $— $(1.3)$(27.0)$(22.9)
April 1,
2025		Transfers in to (out of) Level 3PurchasesSales & Settlements
Realized and Unrealized Gains (Losses) (1)
June 30,
2025
Other long-term investments$87.0 $— $— $— $— $87.0 
Net derivatives (2)
$21.7 $— $— $— $(14.9)$6.8 
January 1, 2025Transfers in to (out of) Level 3PurchasesSales & Settlements
Realized and Unrealized Gains (Losses) (1)
June 30,
2025
Other long-term investments$86.6 $— $— $— $0.4 $87.0 
Net derivatives (2)
$(13.4)$— $— $5.4 $14.8 $6.8 
(1)Total change in realized and unrealized gains (losses) recorded on Level 3 financial instruments is included in net investment gains (losses) in the consolidated statements of income. Realized and unrealized gains (losses) related to underwriting related derivative assets and liabilities are included in other revenues, net of foreign exchange (gains) losses, in the consolidated statements of income. See Note 8 “Derivatives” for classifications of gains (losses) on derivatives.
(2)Derivative assets are presented within Other assets on the consolidated balance sheets and derivative liabilities are presented within Other liabilities on the consolidated balance sheets. The amounts are presented net in the tables above for the purposes of the rollforward.
Schedule of Reconciliation of Liabilities Measured at Fair Value using Level 3 Inputs
The following tables present the reconciliation of investments measured at fair value using Level 3 inputs for the three and six months ended June 30, 2026 and 2025:
April 1,
2026		Transfers in to (out of) Level 3PurchasesSales & Settlements
Realized and Unrealized Gains (Losses) (1)
June 30,
2026
Other long-term investments$63.7 $— $— $— $(6.2)$57.5 
Net derivatives (2)
$(31.7)$— $— $— $8.8 $(22.9)
January 1, 2026Transfers in to (out of) Level 3PurchasesSales & Settlements
Realized and Unrealized Gains(Losses) (1)
June 30,
2026
Other long-term investments$82.9 $— $— $(22.7)$(2.7)$57.5 
Net derivatives (2)
$5.4 $— $— $(1.3)$(27.0)$(22.9)
April 1,
2025		Transfers in to (out of) Level 3PurchasesSales & Settlements
Realized and Unrealized Gains (Losses) (1)
June 30,
2025
Other long-term investments$87.0 $— $— $— $— $87.0 
Net derivatives (2)
$21.7 $— $— $— $(14.9)$6.8 
January 1, 2025Transfers in to (out of) Level 3PurchasesSales & Settlements
Realized and Unrealized Gains (Losses) (1)
June 30,
2025
Other long-term investments$86.6 $— $— $— $0.4 $87.0 
Net derivatives (2)
$(13.4)$— $— $5.4 $14.8 $6.8 
(1)Total change in realized and unrealized gains (losses) recorded on Level 3 financial instruments is included in net investment gains (losses) in the consolidated statements of income. Realized and unrealized gains (losses) related to underwriting related derivative assets and liabilities are included in other revenues, net of foreign exchange (gains) losses, in the consolidated statements of income. See Note 8 “Derivatives” for classifications of gains (losses) on derivatives.
(2)Derivative assets are presented within Other assets on the consolidated balance sheets and derivative liabilities are presented within Other liabilities on the consolidated balance sheets. The amounts are presented net in the tables above for the purposes of the rollforward.
Schedule of Financial Instruments for which the Carrying Value differs from the Estimated Fair Values
The following table includes financial instruments for which the carrying value differs from the estimated fair values as of June 30, 2026 and December 31, 2025. The fair values of the below financial instruments are based on observable inputs and are considered Level 2 measurements.
June 30, 2026December 31, 2025
Fair ValueCarrying ValueFair ValueCarrying Value
2024 Senior Notes$417.6 $396.6 $424.2 $396.0 
2017 SEK Subordinated Notes284.8 278.9 293.3 292.6 
Series B preference shares (1)
$— $— $202.2 $200.0 
(1)The Series B preference shares were fully redeemed on February 26, 2026. See Note 14 for further discussion on the redemption.