Disclosures About Offsetting Assets and Liabilities - Financial Liabilities and Derivative Liabilities that are Subject to Offset (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities, Securities lending	$ (224,378)	$ (135,693)
Net amounts presented in the Statement of Financial Condition, Securities lending	(224,378)	(135,693)
Gross amounts not offset in the Statement of Financial Position, Financial instruments, Securities lending	38,004	23,691
Gross amounts not offset in the Statement of Financial Position, Collateral pledged, Securities lending	186,374	111,981
Securities lending, Net amount	0	(21)
Gross amounts of recognized liabilities, Securities purchased under agreements to resell	(426,659)	(417,644)
Net amounts presented in the Statement of Financial Condition, Securities purchased under agreements to resell	(426,659)	(417,644)
Gross amounts not offset in the Statement of Financial Position, Financial instruments, Securities purchased under agreements to resell	89,403	23,441
Gross amounts not offset in the Statement of Financial Position, Collateral pledged, Securities purchased under agreements to resell	337,256	394,203
Gross amounts of recognized liabilities	(778,717)	(671,988)
Net amounts presented in the Statement of Financial Condition	(778,717)	(671,988)
Gross amounts not offset in the Statement of Financial Position, Financial instruments	132,074	61,688
Gross amounts not offset in the Statement of Financial Condition, Collateral pledged	553,814	528,845
Net amount	(92,829)	(81,455)
Interest Rate Contracts [Member]
Offsetting Liabilities [Line Items]
Gross amounts of recognized liabilities	(127,680)	(118,651)
Net amounts presented in the Statement of Financial Condition	(127,680)	(118,651)
Gross amounts not offset in the Statement of Financial Position, Financial instruments	4,667	14,556
Gross amounts not offset in the Statement of Financial Condition, Collateral pledged	30,184	22,661
Offsetting liability interest rate contracts net	$ (92,829)	$ (81,434)