Fair Value Measurement - Quantitative Information About Level III Inputs (Details) $ in Millions	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($) $ / shares
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	$ 9,136.5
Fair value of liabilities	7,623.9	$ 6,298.6
Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	8,536.7	7,379.4
Fair value of liabilities	7,623.4	6,298.6
Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of liabilities		6,090.1
Investments of Consolidated Funds | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	7,933.5	6,762.2
Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	11.7
BDC preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets		81.7
Consensus Pricing | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	2.3	3.3
Consensus Pricing | Bonds | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	489.5	522.5
Consensus Pricing | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	$ 7,000.1	$ 5,829.3
Consensus Pricing | Indicative Quotes | Minimum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.00	0.00
Consensus Pricing | Indicative Quotes | Minimum | Bonds | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.27	0.30
Consensus Pricing | Indicative Quotes | Minimum | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0	0
Consensus Pricing | Indicative Quotes | Maximum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	191.10	208.38
Consensus Pricing | Indicative Quotes | Maximum | Bonds | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	1.03	1.05
Consensus Pricing | Indicative Quotes | Maximum | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	1.04	1.02
Consensus Pricing | Indicative Quotes | Weighted Average | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.00	0.11
Consensus Pricing | Indicative Quotes | Weighted Average | Bonds | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.91	0.90
Consensus Pricing | Indicative Quotes | Weighted Average | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.98	0.95
Discounted Cash Flow | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	$ 361.5	$ 366.5
Discounted Cash Flow | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	44.5
Discounted Cash Flow | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	10.8	11.0
Discounted Cash Flow | Loan two | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	7.8	9.4
Discounted Cash Flow | Aviation subordinated notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	2.8	$ 2.9
Discounted Cash Flow | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	$ 7.0
Discounted Cash Flow | Discount Rates | Minimum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.10	0.10
Discounted Cash Flow | Discount Rates | Minimum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.12
Discounted Cash Flow | Discount Rates | Minimum | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.11	0.07
Discounted Cash Flow | Discount Rates | Minimum | Loan two | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.17	0.17
Discounted Cash Flow | Discount Rates | Minimum | Aviation subordinated notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.21	0.21
Discounted Cash Flow | Discount Rates | Minimum | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.12
Discounted Cash Flow | Discount Rates | Maximum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.11	0.11
Discounted Cash Flow | Discount Rates | Maximum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.12
Discounted Cash Flow | Discount Rates | Maximum | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.20	0.16
Discounted Cash Flow | Discount Rates | Maximum | Loan two | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.17	0.17
Discounted Cash Flow | Discount Rates | Maximum | Aviation subordinated notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.21	0.21
Discounted Cash Flow | Discount Rates | Maximum | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.16
Discounted Cash Flow | Discount Rates | Weighted Average | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.11	0.10
Discounted Cash Flow | Discount Rates | Weighted Average | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.12
Discounted Cash Flow | Discount Rates | Weighted Average | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.19	0.15
Discounted Cash Flow | Discount Rates | Weighted Average | Loan two | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.17	0.17
Discounted Cash Flow | Discount Rates | Weighted Average | Aviation subordinated notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.21	0.21
Discounted Cash Flow | Discount Rates | Weighted Average | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.14
Discounted Cash Flow | Terminal Growth Rate | Minimum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0	0
Discounted Cash Flow | Terminal Growth Rate | Minimum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.06
Discounted Cash Flow | Terminal Growth Rate | Maximum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.07	0.07
Discounted Cash Flow | Terminal Growth Rate | Maximum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.06
Discounted Cash Flow | Terminal Growth Rate | Weighted Average | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.05	0.05
Discounted Cash Flow | Terminal Growth Rate | Weighted Average | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.06
Discounted Cash Flow | Constant Prepayment Rate | Minimum | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input		0.08
Discounted Cash Flow | Constant Prepayment Rate | Minimum | Loan two | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.08
Discounted Cash Flow | Constant Prepayment Rate | Maximum | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input		0.08
Discounted Cash Flow | Constant Prepayment Rate | Maximum | Loan two | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.14
Discounted Cash Flow | Constant Prepayment Rate | Weighted Average | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input		0.08
Discounted Cash Flow | Constant Prepayment Rate | Weighted Average | Loan two | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.11
Discounted Cash Flow | Default Rates | Minimum | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input		0.01
Discounted Cash Flow | Default Rates | Minimum | Loan two | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.01
Discounted Cash Flow | Default Rates | Maximum | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input		0.01
Discounted Cash Flow | Default Rates | Maximum | Loan two | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.01
Discounted Cash Flow | Default Rates | Weighted Average | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input		0.01
Discounted Cash Flow | Default Rates | Weighted Average | Loan two | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.01
Discounted Cash Flow | Recovery Rates | Minimum | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input		0
Discounted Cash Flow | Recovery Rates | Maximum | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input		0
Discounted Cash Flow | Recovery Rates | Weighted Average | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input		0
Comparable Multiple | EBITDA Multiple | Minimum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	12.5	12.7
Comparable Multiple | EBITDA Multiple | Minimum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	7.2
Comparable Multiple | EBITDA Multiple | Maximum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	12.5	12.7
Comparable Multiple | EBITDA Multiple | Maximum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	7.2
Comparable Multiple | EBITDA Multiple | Weighted Average | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	12.5	12.7
Comparable Multiple | EBITDA Multiple | Weighted Average | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	7.2
Comparable Multiple | TCF Multiple | Minimum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	26.9	24.3
Comparable Multiple | TCF Multiple | Maximum | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	26.9	24.3
Comparable Multiple | TCF Multiple | Weighted Average | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	26.9	24.3
Consensus Pricing with Discounted Cash Flow | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of liabilities	$ 202.4	$ 190.0
Consensus Pricing with Discounted Cash Flow | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	434.9	472.2
Consensus Pricing with Discounted Cash Flow | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	$ 59.7	$ 59.4
Consensus Pricing with Discounted Cash Flow | Indicative Quotes | Minimum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities, measurement input	0.14	0.16
Consensus Pricing with Discounted Cash Flow | Indicative Quotes | Minimum | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.78	0.72
Consensus Pricing with Discounted Cash Flow | Indicative Quotes | Minimum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.04	0.06
Consensus Pricing with Discounted Cash Flow | Indicative Quotes | Maximum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities, measurement input	0.99	1.03
Consensus Pricing with Discounted Cash Flow | Indicative Quotes | Maximum | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	1.01	1.01
Consensus Pricing with Discounted Cash Flow | Indicative Quotes | Maximum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.91	0.90
Consensus Pricing with Discounted Cash Flow | Indicative Quotes | Weighted Average | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities, measurement input	0.59	0.41
Consensus Pricing with Discounted Cash Flow | Indicative Quotes | Weighted Average | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.99	0.96
Consensus Pricing with Discounted Cash Flow | Indicative Quotes | Weighted Average | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.41	0.40
Consensus Pricing with Discounted Cash Flow | Discount Rates | Minimum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities, measurement input	0.07	0.14
Consensus Pricing with Discounted Cash Flow | Discount Rates | Minimum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.09	0.11
Consensus Pricing with Discounted Cash Flow | Discount Rates | Maximum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities, measurement input	0.35	0.30
Consensus Pricing with Discounted Cash Flow | Discount Rates | Maximum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.35	0.40
Consensus Pricing with Discounted Cash Flow | Discount Rates | Weighted Average | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities, measurement input	0.16	0.21
Consensus Pricing with Discounted Cash Flow | Discount Rates | Weighted Average | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.20	0.21
Consensus Pricing with Discounted Cash Flow | Discount Margins | Minimum | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.0109	0.0139
Consensus Pricing with Discounted Cash Flow | Discount Margins | Maximum | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.1500	0.1600
Consensus Pricing with Discounted Cash Flow | Discount Margins | Weighted Average | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.0238	0.0319
Consensus Pricing with Discounted Cash Flow | Default Rates | Minimum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities, measurement input	0.01	0.02
Consensus Pricing with Discounted Cash Flow | Default Rates | Minimum | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.02	0.02
Consensus Pricing with Discounted Cash Flow | Default Rates | Minimum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.01	0.01
Consensus Pricing with Discounted Cash Flow | Default Rates | Maximum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities, measurement input	0.02	0.02
Consensus Pricing with Discounted Cash Flow | Default Rates | Maximum | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.02	0.02
Consensus Pricing with Discounted Cash Flow | Default Rates | Maximum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.02	0.02
Consensus Pricing with Discounted Cash Flow | Default Rates | Weighted Average | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities, measurement input	0.02	0.02
Consensus Pricing with Discounted Cash Flow | Default Rates | Weighted Average | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.02	0.02
Consensus Pricing with Discounted Cash Flow | Default Rates | Weighted Average | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.02	0.02
Consensus Pricing with Discounted Cash Flow | Recovery Rates | Minimum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities, measurement input	0.60	0.60
Consensus Pricing with Discounted Cash Flow | Recovery Rates | Minimum | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.60	0.60
Consensus Pricing with Discounted Cash Flow | Recovery Rates | Minimum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.60	0.60
Consensus Pricing with Discounted Cash Flow | Recovery Rates | Maximum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities, measurement input	0.60	0.60
Consensus Pricing with Discounted Cash Flow | Recovery Rates | Maximum | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.60	0.60
Consensus Pricing with Discounted Cash Flow | Recovery Rates | Maximum | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.60	0.60
Consensus Pricing with Discounted Cash Flow | Recovery Rates | Weighted Average | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Liabilities, measurement input	0.60	0.60
Consensus Pricing with Discounted Cash Flow | Recovery Rates | Weighted Average | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.60	0.60
Consensus Pricing with Discounted Cash Flow | Recovery Rates | Weighted Average | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.60	0.60
Market Yield Analysis | BDC preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	$ 98.8	$ 81.7
Market Yield Analysis | Market Yields | Minimum | BDC preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.11	0.11
Market Yield Analysis | Market Yields | Maximum | BDC preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.11	0.11
Market Yield Analysis | Market Yields | Weighted Average | BDC preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Assets, measurement input	0.11	0.11
Other | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of liabilities	$ 42.2
Other | Senior secured notes | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of liabilities	7,378.8
Other | Equity securities | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets		$ 7.8
Other | Loans | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets	$ 5.3	12.4
Other | Subordinated notes and preferred shares | Level III
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of assets		1.0
Fair value of liabilities		$ 18.5