Borrowings and Financing Activities - Schedule of Senior Notes (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Total secured borrowings	$ 119,476	$ 155,822
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
FHLB, floating-rate advances	$ 13,000
FHLB weighted average interest rate	5.602%	3.617%
Senior notes
Debt Instrument [Line Items]
Long-term debt	$ 1,417,781	$ 1,413,504
Senior notes | Senior Notes due 2024
Debt Instrument [Line Items]
Interest rate on senior notes	4.50%
Long-term debt	$ 449,037	447,805
Senior notes | Senior Notes due 2025
Debt Instrument [Line Items]
Interest rate on senior notes	6.625%
Long-term debt	$ 522,343	520,305
Senior notes | Senior Notes due 2027
Debt Instrument [Line Items]
Interest rate on senior notes	4.875%
Long-term debt	$ 446,401	445,394
FHLB advances
Debt Instrument [Line Items]
FHLB advances due in 2023, average interest rate	0.00%
FHLB advances due in 2024, average interest rate	4.66%
FHLB advances due in 2025, average interest rate	2.34%
FHLB advances due in 2026, average interest rate	4.469%
FHLB advances due in 2027, average interest rate	2.562%
FHLB advances due 2023	$ 0	104,895
FHLB advances due 2024	72,871	32,371
FHLB advances due 2025	12,684	9,984
FHLB advances due 2026	1,835	0
FHLB advances due 2027	7,887	6,436
Total FHLB advances	95,277	153,686
Mortgage financing facilities
Debt Instrument [Line Items]
Long-term debt	$ 24,199	$ 2,136
Mortgage financing facilities, average interest rate	6.975%