Income Taxes - Valuation Allowance (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
Valuation Allowance [Line Items]
Valuation allowance	$ 95.8	$ 89.2
Financial Guarantee (HG Global) \| BAM
Valuation Allowance [Line Items]
Increase (decrease) in valuation allowance		5.7
Net Operating Losses in Luxembourg Subsidiaries
Valuation Allowance [Line Items]
Valuation allowance	36.8	20.6
U S Losses and Other Federal Deferred Tax Benefits
Valuation Allowance [Line Items]
Valuation allowance	35.3	43.4
Net Operating Losses in Israel Subsidiaries
Valuation Allowance [Line Items]
Valuation allowance	23.6	25.2
Net Operating Losses in United Kingdom Subsidiaries
Valuation Allowance [Line Items]
Valuation allowance	0.1
Net Deferred Tax Assets For Certain U.S. Operations - Other Operations
Valuation Allowance [Line Items]
Increase (decrease) in valuation allowance	(10.3)	8.6
Net Deferred Tax Assets For BAM
Valuation Allowance [Line Items]
Increase (decrease) in valuation allowance		(3.1)
Investments Held in Luxembourg-Domiciled Subsidiaries
Valuation Allowance [Line Items]
Increase (decrease) in valuation allowance	6.6	4.2
Investments Held in Luxembourg-Domiciled Subsidiaries, Partial Release Related to Expected Future Interest Income
Valuation Allowance [Line Items]
Increase (decrease) in valuation allowance	3.9
Investments Held in Israel-Domiciled Subsidiaries
Valuation Allowance [Line Items]
Increase (decrease) in valuation allowance	$ 3.0	$ (0.2)

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

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+ References

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