Balance Sheet Offsetting - Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Total
Gross Amounts of Recognized Liabilities	$ 1,496,275	$ 1,635,306
Net Amounts of Liabilities Presented in the Balance Sheet	1,496,275	1,635,306
Gross Amounts Not Offset in the Balance Sheet
Financial Instruments	(1,409,661)	(1,541,474)
Cash Collateral Pledged		(10,515)
Net Amount	86,614	83,317
Institutional Counterparties
Securities loaned:
Gross Amounts of Recognized Liabilities	1,291,725	1,371,896
Net Amounts of Liabilities Presented in the Balance Sheets	1,291,725	1,371,896
Gross Amounts Not Offset in the Balance Sheet
Financial Instruments	(1,211,426)	(1,296,828)
Net Amount	80,299	75,068
Institutional Counterparties | Interest Rate Swap
Derivatives:
Gross Amounts of Recognized Liabilities	514	5,349
Net Amounts of Liabilities Presented in the Balance Sheet	514	5,349
Gross Amounts Not Offset in the Balance Sheet
Financial Instruments		(5,349)
Net Amount	514	0
Institutional Counterparties | Repurchase Agreements
Repurchase agreements:
Gross Amounts of Recognized Liabilities	198,174	239,103
Net Amounts of Liabilities Presented in the Balance Sheet	198,174	239,103
Gross Amounts Not Offset in the Balance Sheet
Financial Instruments	(198,174)	(239,103)
Net Amount	0	0
Institutional Counterparties | Forward MBS Derivatives
Derivatives:
Gross Amounts of Recognized Liabilities	5,862	18,958
Net Amounts of Liabilities Presented in the Balance Sheet	5,862	18,958
Gross Amounts Not Offset in the Balance Sheet
Financial Instruments	(61)	(194)
Cash Collateral Pledged		(10,515)
Net Amount	$ 5,801	$ 8,249