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Income Taxes - Valuation Allowance (Detail) - USD ($) $ in Millions | 12 Months Ended
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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)

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- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. + References 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 + Details
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- Definition Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset. + 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 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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