Borrowings - CLO Borrowings (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Borrowing Outstanding	$ 6,523.3	$ 6,083.2
CLO Term Loan February 2017 Maturing September 21, 2029
Debt Instrument [Line Items]
Borrowing Outstanding	$ 39.9	38.7
CLO Term Loan February 2017 Maturing September 21, 2029 | Euribor
Debt Instrument [Line Items]
Interest Rate	6.02%
CLO Term Loan June 2017 Maturing July 20, 2030
Debt Instrument [Line Items]
Borrowing Outstanding	$ 45.6	54.8
CLO Term Loan June 2017 Maturing July 20, 2030 | SOFR
Debt Instrument [Line Items]
Interest Rate	6.86%
Applicable margin over base rate	1.45%
CLO Term Loan December 2017 Maturing January 15, 2031
Debt Instrument [Line Items]
Borrowing Outstanding	$ 41.1	43.8
CLO Term Loan December 2017 Maturing January 15, 2031 | SOFR
Debt Instrument [Line Items]
Interest Rate	7.04%
Applicable margin over base rate	1.64%
CLO Term Loan March 2019 Maturing March 2032
Debt Instrument [Line Items]
Borrowing Outstanding	$ 1.8	1.8
CLO Term Loan March 2019 Maturing March 2032 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	12.03%
CLO Term Loan August 2019 Maturing August 2032
Debt Instrument [Line Items]
Borrowing Outstanding	$ 4.0	3.9
CLO Term Loan August 2019 Maturing August 2032 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	8.74%
CLO Term Loan September 2020 Maturing April 2033
Debt Instrument [Line Items]
Borrowing Outstanding	$ 19.7	19.1
CLO Term Loan September 2020 Maturing April 2033 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	5.55%
CLO Term Loan 2021 Maturing January 2034
Debt Instrument [Line Items]
Borrowing Outstanding	$ 20.6	19.9
CLO Term Loan 2021 Maturing January 2034 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	6.46%
CLO Term Loan Maturing August 15, 2030
Debt Instrument [Line Items]
Borrowing Outstanding	$ 16.8	19.1
CLO Term Loan Maturing August 15, 2030 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	5.41%
CLO Term Loan March 2021 Maturing March 2032
Debt Instrument [Line Items]
Borrowing Outstanding	$ 18.6	18.0
CLO Term Loan March 2021 Maturing March 2032 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	5.63%
CLO Term Loan 2021 Maturing April 2033
Debt Instrument [Line Items]
Borrowing Outstanding	$ 3.6	3.4
CLO Term Loan 2021 Maturing April 2033 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	9.81%
CLO Term Loan May 2021 Maturing November 2031
Debt Instrument [Line Items]
Borrowing Outstanding	$ 15.5	15.0
CLO Term Loan May 2021 Maturing November 2031 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	5.37%
CLO Term Loan June 2021 Maturing January 2034
Debt Instrument [Line Items]
Borrowing Outstanding	$ 20.7	20.0
CLO Term Loan June 2021 Maturing January 2034 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	6.24%
CLO Term Loan June 2021 Maturing November 2031
Debt Instrument [Line Items]
Borrowing Outstanding	$ 1.3	1.3
CLO Term Loan June 2021 Maturing November 2031 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	6.85%
CLO Term Loan July 2021 Maturing July 2034
Debt Instrument [Line Items]
Borrowing Outstanding	$ 15.5	15.0
CLO Term Loan July 2021 Maturing July 2034 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	6.26%
CLO Term Loan July 2021 Maturing July 2031
Debt Instrument [Line Items]
Borrowing Outstanding	$ 20.6	20.0
CLO Term Loan July 2021 Maturing July 2031 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	6.27%
CLO Term Loan August 2021 Maturing August 2032
Debt Instrument [Line Items]
Borrowing Outstanding	$ 16.7	16.2
CLO Term Loan August 2021 Maturing August 2032 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	5.75%
CLO Term Loan October 2021 Maturing October 2035
Debt Instrument [Line Items]
Borrowing Outstanding	$ 24.0	23.3
CLO Term Loan October 2021 Maturing October 2035 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	6.37%
CLO Term Loan November 2021 Maturing January 2034
Debt Instrument [Line Items]
Borrowing Outstanding	$ 14.3	13.8
CLO Term Loan November 2021 Maturing January 2034 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	6.05%
CLO Term Loan January 2022 Maturing February 2035
Debt Instrument [Line Items]
Borrowing Outstanding	$ 20.7	20.1
CLO Term Loan January 2022 Maturing February 2035 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	6.38%
CLO Term Loan February 2022 Maturing November 2035
Debt Instrument [Line Items]
Borrowing Outstanding	$ 20.8	20.1
CLO Term Loan February 2022 Maturing November 2035 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	6.43%
CLO Term Loan July 2022 Maturing January 2035
Debt Instrument [Line Items]
Borrowing Outstanding	$ 17.5	16.9
CLO Term Loan July 2022 Maturing January 2035 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	7.27%
CLO Term Loan October 2022 Maturing October 2035
Debt Instrument [Line Items]
Borrowing Outstanding	$ 18.1	17.5
CLO Term Loan October 2022 Maturing October 2035 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	7.70%
CLO Term Loan September 2023 Maturing August 2031
Debt Instrument [Line Items]
Borrowing Outstanding	$ 14.3	0.0
CLO Term Loan September 2023 Maturing August 2031 | Average effective interest rate
Debt Instrument [Line Items]
Interest Rate	5.43%
CLO Term Loans
Debt Instrument [Line Items]
Borrowing Outstanding	$ 431.7	$ 421.7
CLO Term Loan Various | Average effective interest rate
Debt Instrument [Line Items]
Applicable margin over base rate	0.50%