Borrowings - CLO Borrowings (Details) € in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2023 EUR (€)	Dec. 31, 2022 USD ($)
CLO Term Loan February 2017 Maturing September 2029
Debt Instrument [Line Items]
Borrowing Outstanding	$ 38.2	€ 36.1	$ 38.7
CLO Term Loan February 2017 Maturing September 2029 \| Euribor
Debt Instrument [Line Items]
Interest Rate	5.55%	5.55%
CLO Term Loan June 2017 Maturing July 20, 2030
Debt Instrument [Line Items]
Borrowing Outstanding	$ 50.0		54.8
CLO Term Loan June 2017 Maturing July 20, 2030 \| SOFR
Debt Instrument [Line Items]
Interest Rate	6.79%	6.79%
Margin spread on interest rate (percent)	1.46%
CLO Term Loan December 2017 Maturing January 15, 2031
Debt Instrument [Line Items]
Borrowing Outstanding	$ 42.7		43.8
CLO Term Loan December 2017 Maturing January 15, 2031 \| SOFR
Debt Instrument [Line Items]
Interest Rate	6.95%	6.95%
Margin spread on interest rate (percent)	1.64%
CLO Term Loan March 2019 Maturing March 2032
Debt Instrument [Line Items]
Borrowing Outstanding	$ 1.7		1.8
CLO Term Loan March 2019 Maturing March 2032 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	11.95%	11.95%
CLO Term Loan August 2019 Maturing August 2032
Debt Instrument [Line Items]
Borrowing Outstanding	$ 3.8		3.9
CLO Term Loan August 2019 Maturing August 2032 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	8.52%	8.52%
CLO Term Loan September 2020 Maturing April 2033
Debt Instrument [Line Items]
Borrowing Outstanding	$ 18.8		19.1
CLO Term Loan September 2020 Maturing April 2033 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	5.25%	5.25%
CLO Term Loan Maturing January 2034
Debt Instrument [Line Items]
Borrowing Outstanding	$ 19.7		19.9
CLO Term Loan Maturing January 2034 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	6.16%	6.16%
CLO Term Loan Maturing August 2030
Debt Instrument [Line Items]
Borrowing Outstanding	$ 17.5		19.1
CLO Term Loan Maturing August 2030 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	5.17%	5.17%
CLO Term Loan March 2021 Maturing March 2032
Debt Instrument [Line Items]
Borrowing Outstanding	$ 17.8		18.0
CLO Term Loan March 2021 Maturing March 2032 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	5.55%	5.55%
CLO Term Loan Maturing April 2033
Debt Instrument [Line Items]
Borrowing Outstanding	$ 3.4		3.4
CLO Term Loan Maturing April 2033 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	9.51%	9.51%
CLO Term Loan May2021 Maturing November2031
Debt Instrument [Line Items]
Borrowing Outstanding	$ 14.8		15.0
CLO Term Loan May2021 Maturing November2031 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	5.15%	5.15%
CLO Term Loan June 2021 Maturing January 2034
Debt Instrument [Line Items]
Borrowing Outstanding	$ 19.8		20.0
CLO Term Loan June 2021 Maturing January 2034 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	5.94%	5.94%
CLO Term Loan Maturing November 2031
Debt Instrument [Line Items]
Borrowing Outstanding	$ 1.3		1.3
CLO Term Loan Maturing November 2031 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	6.63%	6.63%
CLO Term Loan July 2021 Maturing July 15, 2034
Debt Instrument [Line Items]
Borrowing Outstanding	$ 14.8		15.0
CLO Term Loan July 2021 Maturing July 15, 2034 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	5.96%	5.96%
CLO Term Loan July 2021 Maturing July 20, 2031
Debt Instrument [Line Items]
Borrowing Outstanding	$ 19.7		20.0
CLO Term Loan July 2021 Maturing July 20, 2031 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	5.98%	5.98%
CLO Term Loan August 2021 Maturing August 2032
Debt Instrument [Line Items]
Borrowing Outstanding	$ 16.0		16.2
CLO Term Loan August 2021 Maturing August 2032 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	5.53%	5.53%
CLO Term Loan October 2021 Maturing October 2035
Debt Instrument [Line Items]
Borrowing Outstanding	$ 23.0		23.3
CLO Term Loan October 2021 Maturing October 2035 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	6.07%	6.07%
CLO Term Loan November 2021 Maturing January 2034
Debt Instrument [Line Items]
Borrowing Outstanding	$ 13.7		13.8
CLO Term Loan November 2021 Maturing January 2034 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	5.75%	5.75%
CLO Term Loan January 2022 Maturing February 15, 2035
Debt Instrument [Line Items]
Borrowing Outstanding	$ 19.8		20.1
CLO Term Loan January 2022 Maturing February 15, 2035 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	6.16%	6.16%
CLO Term Loan February 2022 Maturing November 10, 2035
Debt Instrument [Line Items]
Borrowing Outstanding	$ 19.9		20.1
CLO Term Loan February 2022 Maturing November 10, 2035 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	6.22%	6.22%
CLO Term Loan July 2022 Maturing January 13, 2035
Debt Instrument [Line Items]
Borrowing Outstanding	$ 16.7		16.9
CLO Term Loan July 2022 Maturing January 13, 2035 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	6.99%	6.99%
CLO Term Loan October 2022 Maturing October 2035
Debt Instrument [Line Items]
Borrowing Outstanding	$ 17.3		17.5
CLO Term Loan October 2022 Maturing October 2035 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	7.48%	7.48%
CLO Term Loan September 2023 Maturing August 2031
Debt Instrument [Line Items]
Borrowing Outstanding	$ 14.6		0.0
CLO Term Loan September 2023 Maturing August 2031 \| Average Effective Interest Rate
Debt Instrument [Line Items]
Interest Rate	5.27%	5.27%
CLO Borrowings
Debt Instrument [Line Items]
Borrowing Outstanding	$ 425.0		$ 421.7
CLO Term Loan Various \| Average Effective Interest Rate
Debt Instrument [Line Items]
Margin spread on interest rate (percent)	0.50%