Significant Transactions - Schedule of Assets Acquired and Liabilities Assumed, Bamboo (Details) - USD ($) $ in Millions |
Jun. 30, 2026 |
Mar. 31, 2026 |
Dec. 31, 2025 |
Sep. 02, 2025 |
Jun. 30, 2025 |
Mar. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|---|---|---|---|---|
| Other Significant Transactions [Line Items] | |||||||
| Goodwill | $ 795.9 | $ 615.3 | $ 614.1 | $ 534.6 | $ 439.2 | $ 439.2 | |
| Distinguished Transaction | |||||||
| Other Significant Transactions [Line Items] | |||||||
| Short-term investments, at fair value | $ 78.1 | ||||||
| Restricted cash | 0.4 | ||||||
| Cash (restricted $0.4) | 1.1 | ||||||
| Premiums, commissions and fees receivable | 34.6 | ||||||
| Other assets | 11.3 | ||||||
| Debt | (100.6) | ||||||
| Premiums and commissions payable | (72.9) | ||||||
| Other liabilities | (53.4) | ||||||
| Net tangible assets acquired (liabilities assumed) | (101.8) | ||||||
| Goodwill | 421.8 | ||||||
| Other intangible assets | 198.2 | ||||||
| Deferred tax liabilities related to investment basis differences | (24.0) | ||||||
| Net assets acquired | $ 494.2 |
| X | ||||||||||
- Definition Amount of cash and cash equivalent acquired in business combination and recognized at acquisition date. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of investment in debt and equity securities acquired in business combination and recognized at acquisition date, classified as current. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of identifiable intangible asset acquired in business combination and recognized at acquisition date. Excludes goodwill and financial asset. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of long-term debt assumed in business combination and recognized at acquisition date, classified as noncurrent. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of asset acquired in excess of (less than) liability assumed plus goodwill in business combination and recognized at acquisition date. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Excluding Goodwill, Deferred Tax Liability No definition available.
|
| X | ||||||||||
- Definition Business Combination, Recognized Assets Acquired, Other Assets No definition available.
|
| X | ||||||||||
- Definition Business Combination, Recognized Assets Acquired, Premiums and Commissions Receivable No definition available.
|
| X | ||||||||||
- Definition Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Net Tangible Assets No definition available.
|
| X | ||||||||||
- Definition Business Combination, Recognized Liabilities Assumed, Other Liabilities No definition available.
|
| X | ||||||||||
- Definition Business Combination, Recognized Liability Assumed, Premiums and Commissions Payable No definition available.
|
| X | ||||||||||
- Definition Other Significant Transactions [Line Items] No definition available.
|
| X | ||||||||||
- Details
|