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Fair Value, Option, Number Of Investments

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Fair value of investment other than investment in equity security, investment in debt security and equity method investment. Includes, but is not limited to, investment in certain entities that calculate net asset value per share. Example includes, but is not limited to, investment in hedge fund, venture capital fund, private equity fund, and real estate partnership or fund.

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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.

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Aggregate gain on all derivative instruments recognized in earnings during the period, before tax effects.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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Fair value portion of other assets.

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Amount before tax and reclassification adjustments of other comprehensive income (loss).

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Percentage of an entity's outstanding debt that is designated as a hedged item in cash flow, fair value, or net investment hedge.

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Fair Value Measurements and the Fair Value Option - Additional Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) investment	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) investment	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Number of investments electing fair value option \| investment	72		72
Gross foreign currency translation loss on net assets			$ 2.9
Principal co-investments	$ (56.1)	$ 30.3	(33.4)	$ 147.9
Reported Value Measurement
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Long-term debt fair value	$ 5,300.0		5,300.0		$ 5,600.0
Interest Rate Swaps and Caps \| Not Designated as Hedging Instrument
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Gain on derivatives			19.3	48.9
Interest Rate Swaps
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Principal co-investments			1.4	18.9
Interest Rate Swaps \| Designated as Hedging Instrument
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Gain on derivatives				$ 6.8
Foreign Currency Translation
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Gross foreign currency translation loss on net assets			$ (6.4)
Foreign Currency Translation \| Euro
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percentage of asset carrying values hedged	93.00%		93.00%
Foreign Currency Translation \| GBP
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percentage of asset carrying values hedged	91.00%		91.00%
Level 3 \| Capitalization Rates \| Income approach - discounted cash flow
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Measurement inputs	0.05		0.05
Level 2 \| Estimate of Fair Value Measurement
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Long-term debt fair value	$ 4,600.0		$ 4,600.0		5,000.0
Minimum \| Credit Spread
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Measurement inputs	0.0088		0.0088
Minimum \| Level 3 \| Capitalization Rates \| Income approach - discounted cash flow
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Measurement inputs	0.0500		0.0500
Minimum \| Level 3 \| Discount Rates \| Income approach - discounted cash flow
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Measurement inputs	0.0725		0.0725
Maximum \| Credit Spread
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Measurement inputs	0.0725		0.0725
Maximum \| Level 3 \| Capitalization Rates \| Income approach - discounted cash flow
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Measurement inputs	0.0750		0.0750
Maximum \| Level 3 \| Discount Rates \| Income approach - discounted cash flow
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Measurement inputs	0.0975		0.0975
Equity Method Investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value option	$ 1,940.9		$ 1,940.9		1,891.1
Alternative investment	$ 148.3		$ 148.3		$ 202.6