Investment Securities - Investments In Private Equity Funds Subject to Lock-Up Periods (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Investment securities
1 – 3 years	$ 18.0
3 – 5 years	51.1
5 – 10 years	159.4
>10 years	21.0
Total	2,150.2	$ 1,998.2
Private equity funds
Investment securities
Total	$ 249.5

Amount of long-term investments classified as other.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(f))
-Publisher FASB
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(12))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
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-Section S99
-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
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Other Long-term Investments, Remaining Period, Five to Ten Years

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Other Long-term Investments, Remaining Period, Greater than 10 Years

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Other Long-term Investments, Remaining Period, One to Three Years

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Other Long-term Investments, Remaining Period, Three to Five Years

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