CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Common shares, par value per share (in dollars per share)	$ 1	$ 1
Common shares, authorized shares (in shares)	50,000,000	50,000,000
Common shares, issued shares (in shares)	2,479,677	2,568,148
Common shares, outstanding shares (in shares)	2,479,677	2,568,148
Operating Segments | P&C Insurance and Reinsurance (Ark/WM Outrigger)
Restricted cash	$ 1.1	$ 14.1
Operating Segments | Specialty Insurance Distribution (Distinguished)
Restricted cash	$ 0.1	$ 0.0