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v3.25.4

Segment Information - Assets (Details) - USD ($) $ in Millions | Dec. 31, 2025 | Dec. 31, 2024
--- | --- | ---
Segment reporting information |  |
Total investments | $ 8,323.9 | $ 6,417.6
Total assets | 12,306.5 | 9,925.6
Total liabilities | 6,051.4 | 4,794.6
Redeemable noncontrolling interests | 131.5 | 0.0
Total White Mountains’s common shareholders’ equity | 5,425.4 | 4,483.7
Nonredeemable noncontrolling interests | 698.2 | 647.3
Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger) |  |
Segment reporting information |  |
Total investments | 3,926.5 | 3,139.7
Total assets | 6,354.1 | 5,299.0
Total liabilities | 4,528.5 | 3,664.8
Redeemable noncontrolling interests | 0.0 |
Total White Mountains’s common shareholders’ equity | 1,360.4 | 1,223.8
Nonredeemable noncontrolling interests | 465.2 | 410.4
Operating Segments | Financial Guarantee (HG Global) |  |
Segment reporting information |  |
Total investments | 784.2 | 667.6
Total assets | 1,236.8 | 1,179.4
Total liabilities | 499.5 | 464.1
Redeemable noncontrolling interests | 0.0 |
Total White Mountains’s common shareholders’ equity | 755.7 | 728.7
Nonredeemable noncontrolling interests | (18.4) | (13.4)
Dividends payable | 527.2 | 462.1
Operating Segments | Asset Management (Kudu) |  |
Segment reporting information |  |
Total investments | 1,313.3 | 1,041.9
Total assets | 1,402.3 | 1,108.4
Total liabilities | 446.9 | 316.7
Redeemable noncontrolling interests | 0.0 |
Total White Mountains’s common shareholders’ equity | 814.2 | 664.1
Nonredeemable noncontrolling interests | 141.2 | 127.6
Operating Segments | Specialty Insurance Distribution (Distinguished) |  |
Segment reporting information |  |
Total investments | 94.0 | 0.0
Total assets | 735.4 | 0.0
Total liabilities | 307.1 | 0.0
Redeemable noncontrolling interests | 131.5 |
Total White Mountains’s common shareholders’ equity | 223.1 | 0.0
Nonredeemable noncontrolling interests | 73.7 | 0.0
Other Operations |  |
Segment reporting information |  |
Total investments | 2,205.9 | 1,568.4
Total assets | 2,577.9 | 2,338.8
Total liabilities | 269.4 | 349.0
Redeemable noncontrolling interests | 0.0 |
Total White Mountains’s common shareholders’ equity | 2,272.0 | 1,867.1
Nonredeemable noncontrolling interests | 36.5 | 122.7
Other Operations | Other Disposal Group |  |
Segment reporting information |  |
Total investments | $ 1.0 | 2.0
Other Operations | Bamboo Group |  |
Segment reporting information |  |
Total investments |  | $ 58.0

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