Fair Value Measurement - Summary of Quantitative Information about Level III Inputs (Details) $ in Millions | Sep. 30, 2021USD ($) | Dec. 31, 2020USD ($) |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | | |
Fair value of assets | $ 6,957.2 | $ 6,628.4 |
Fair value of liabilities | 5,938.5 | 5,563.4 |
Level III | | |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | | |
Fair value of assets | 6,876.3 | 6,627.7 |
Fair value of liabilities | 5,938.3 | 5,563 |
Senior secured notes | Level III | | |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | | |
Fair value of liabilities | 5,700.1 | 5,358.9 |
Investments of Consolidated Funds | Level III | | |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | | |
Fair value of assets | 6,452.9 | 6,056.9 |
Consensus Pricing | Equity securities | Level III | | |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | | |
Fair value of assets | 18.9 | 9.4 |
Consensus Pricing | Bonds | Level III | | |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | | |
Fair value of assets | 581.1 | 550.4 |
Consensus Pricing | Loans | Level III | | |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | | |
Fair value of assets | $ 5,834.3 | 5,497.1 |
Consensus Pricing | Loans | Level III | | |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | | |
Fair value of assets | | $ 14.1 |
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 | 0 |
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 | 94 | 0.85 |
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 | 0.37 | 0.15 |
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 | | 0.98 |
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 | 74.50 | 40 |
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 | 1.09 | 1.08 |
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 | 1.09 | 1.08 |
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 |
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 | 0.66 | 0.57 |
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 | 1 | 0.98 |
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 | 0.99 | 0.97 |
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 | | 1 |
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 | $ 238.2 | $ 204.1 |
Consensus Pricing with Discounted Cash Flow | Loans | Level III | | |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | | |
Fair value of assets | 18.6 | |
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 | 274.9 | 437 |
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 | $ 69.8 | $ 52.5 |
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 | 0.42 | 0.30 |
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 | 0.84 | 0.71 |
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 | 0.43 | 0.31 |
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 | 0.77 | 0.91 |
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 |
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 | 0.88 | 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 | 0.56 | 0.50 |
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 | 0.98 |
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 | 0.72 | 0.46 |
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 | 0.0050 | 0.0085 |
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 | 0.1330 | 0.1725 |
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 | 0.0256 | 0.0227 |
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 | 0.01 |
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 | 0.01 | 0.01 |
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 | 0.01 | 0.01 |
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 | 0.01 | 0.01 |
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 | 0.01 | 0.01 |
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 | 0.50 | 0.50 |
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 | 0.50 | 0.50 |
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 | 0.50 | 0.50 |
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 | 0.70 | 0.70 |
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 | 0.70 | 0.70 |
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 | 0.70 | 0.70 |
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 |
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 | 0.15 | 0.16 |
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 | 0.10 | 0.16 |
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 | 0.25 | 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 | 0.25 | 0.30 |
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 | 0.20 | 0.22 |
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 | 0.17 | 0.23 |
Discounted Cash Flow | BDC preferred shares | Level III | | |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | | |
Fair value of assets | $ 71.8 | $ 60 |
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 | $ 6.9 | $ 7.2 |
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 | 0.03 | |
Discounted Cash Flow | Discount Rates | Minimum | BDC preferred shares | 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 | 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 | 0.16 | 0.20 |
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 | 0.08 | |
Discounted Cash Flow | Discount Rates | Maximum | BDC preferred shares | 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 | 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 | 0.16 | 0.20 |
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 | 0.06 | |
Discounted Cash Flow | Discount Rates | Weighted Average | BDC preferred shares | Level III | | |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | | |
Assets, measurement input | 0.07 | 0.07 |
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 | 0.16 | 0.20 |