Borrowings - Narrative (Details) - USD ($)			1 Months Ended	3 Months Ended
	Jun. 01, 2022	Jun. 01, 2012	Jan. 31, 2010	Dec. 31, 2023	Dec. 31, 2022	Oct. 12, 2023	Oct. 11, 2023	Sep. 30, 2023	Oct. 13, 2022
Line of Credit Facility [Abstract]
Loss on extinguishment of debt, net				$ 13,000	$ 515,000
Junior Subordinated Notes [Abstract]
Total outstanding borrowings of unconsolidated entities				974,644,000				$ 978,028,000
Senior Notes
Junior Subordinated Notes [Abstract]
Total outstanding borrowings of unconsolidated entities				899,791,000				903,691,000
6.750% | Senior Notes
Line of Credit Facility [Abstract]
Extinguishment of debt				4,300,000
Loss on extinguishment of debt, net				100,000
Junior Subordinated Notes [Abstract]
Total outstanding borrowings of unconsolidated entities				197,915,000				202,195,000
5.875% | Senior Notes
Junior Subordinated Notes [Abstract]
Total outstanding borrowings of unconsolidated entities				357,255,000				357,255,000
Junior Subordinated Notes
Junior Subordinated Notes [Abstract]
Aggregate principle balance of notes				$ 100,800,000
Weighted average fixed interest rate of debt				8.10%
Junior Subordinated Debt, Modified Terms
Junior Subordinated Notes [Abstract]
Aggregate principal amount of debt			$ 75,000,000
Redemption price percentage		75.00%
Annual increase of percentage of principal amount redeemable	1.785%
Junior Subordinated Debt, Modified Terms | LIBOR
Junior Subordinated Notes [Abstract]
Variable rate floor			4.25%
Variable rate cap			9.25%
Junior Subordinated Debt, Original Terms
Junior Subordinated Notes [Abstract]
Aggregate principal amount of debt				$ 25,800,000
Junior Subordinated Debt, Original Terms | LIBOR
Junior Subordinated Notes [Abstract]
Basis spread on variable rate			2.71%	2.45%
Senior Unsecured Revolving Credit Facility
Line of Credit Facility [Abstract]
Credit facility, maximum borrowing capacity									$ 400,000,000
Credit facility, available increase in borrowing capacity									$ 100,000,000
Senior Unsecured Revolving Credit Facility				$ 0				0
Letters of credit secured using cash collateral				0
Amount of available borrowings under the secured revolving credit facility				300,000,000
Senior Unsecured Revolving Credit Facility | Senior Notes
Line of Credit Facility [Abstract]
Credit facility, maximum borrowing capacity						$ 300,000,000	$ 265,000,000
Letter of Credit
Line of Credit Facility [Abstract]
Letters of credit secured using cash collateral				$ 36,700,000				$ 31,200,000
Letter of Credit | Senior Notes
Line of Credit Facility [Abstract]
Credit facility, maximum borrowing capacity						$ 100,000,000