Total Equity - Net Changes In Capitalization (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Redemption of Series C and Series D cumulative preferred shares	$ 53.5
As presented in other net changes in capitalization in the consolidated statement of changes in equity	(555.5)	$ (319.3)
Common shareholders' equity
Redemption of Series C and Series D cumulative preferred shares	53.5
Other	(75.0)	(63.0)
As presented in other net changes in capitalization in the consolidated statement of changes in equity	(42.0)	(67.2)
Non-controlling interests
Other	29.5	(30.9)
As presented in other net changes in capitalization in the consolidated statement of changes in equity	(513.5)	(252.1)
RiverStone Barbados \| Common shareholders' equity \| RiverStone Barbados AVLNs
Purchase of certain securities held through AVLNs		(45.1)
RiverStone Barbados \| Non-controlling interests \| RiverStone Barbados AVLNs
Purchase of certain securities held through AVLNs		(178.0)
Thomas Cook India \| Common shareholders' equity
Partial disposition of shares		45.8
Thomas Cook India \| Non-controlling interests
Partial disposition of shares		19.8
Fairfax India \| Common shareholders' equity
Fairfax India share repurchases	(0.8)	(1.9)
Fairfax India \| Non-controlling interests
Fairfax India share repurchases	(7.6)	(35.4)
Allied World \| Common shareholders' equity
Acquisition of non-controlling interests		(3.0)
Allied World \| Non-controlling interests
Acquisition of non-controlling interests		$ (27.6)
Brit \| Common shareholders' equity
Acquisition of non-controlling interests	(76.0)
Brit \| Non-controlling interests
Acquisition of non-controlling interests	(449.9)
Gulf Insurance \| Common shareholders' equity
Additional interest acquired in Gulf Insurance through mandatory tender offer (note 21)	(41.2)
Gulf Insurance \| Non-controlling interests
Additional interest acquired in Gulf Insurance through mandatory tender offer (note 21)	(85.5)
Digit \| Common shareholders' equity
Partial disposition of Digit Insurance by Digit on completion of Digit Insurance's initial public offering (note 6)	$ 97.5

Amount of decrease in equity from acquisition of a portion of non-controlling interest.

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The amount of gain (loss) on redemption of preferred shares recognized in the statement of equity during the reporting period.

+ References

No definition available.

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The amount of increase (decrease) in equity related to net changes in capitalization during the period.

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The increase (decrease) in the equity resulting from the partial disposition of shares in the subsidiary of the entity's associate during the reporting period.

+ References

No definition available.

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The increase (decrease) in equity resulting from purchase of certain securities held through AVLNs.

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Increase (Decrease) Through Other, Equity

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The increase in equity resulting from the partial disposition of subsidiary shares.

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The increase (decrease) in equity through changes in ownership interests in subsidiaries that do not result in loss of control. [Refer: Total for all subsidiaries [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

The increase (decrease) in equity resulting from treasury share transactions. [Refer: Equity; Treasury shares]

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