Offsetting of Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financial derivatives–assets
Financial derivatives–assets, at fair value	$ 150,343	$ 143,996
Financial Instruments Available for Offset	(39,285)	(50,301)
Cash Collateral (Received) Pledged	(60,648)	(38,812)
Net Amount	50,410	54,883
Reverse repurchase agreements
Reverse repurchase agreements	183,607	173,145
Financial Instruments Available for Offset	(167,125)	(155,719)
Cash Collateral (Received) Pledged	0	0
Net Amount	0	0
Financial derivatives–liabilities
Financial derivatives–liabilities, at fair value-	(40,425)	(61,776)
Financial Instruments Available for Offset	39,285	50,301
Cash Collateral (Received) Pledged	122	3,822
Net Amount	(1,018)	(7,653)
Repurchase agreements
Reverse repurchase agreements	(2,517,747)	(2,967,437)
Financial Instruments Available for Offset	167,125	155,719
Securities Collateral relating to Reverse Repurchase Agreements	3,100,000	3,700,000
Cash Collateral (Received) Pledged	2,248	(11,194)
Net Amount	0	0
Financial Derivatives - Assets
Financial derivatives–assets
Derivative Asset, Fair Value of Collateral	0	0
Repurchase agreements
Excess cash collateral	1,200	(13,900)
Securities Purchased under Agreements to Resell [Member]
Reverse repurchase agreements
Securities Purchased under Agreements to Resell, Fair Value of Collateral	(16,482)	(17,426)
Financial Derivatives - Liabilities
Financial derivatives–liabilities
Derivative Liability, Fair Value of Collateral	0	0
Repurchase agreements
Excess cash collateral	300	12,100
Reverse repurchase agreements
Repurchase agreements
Securities Collateral relating to Reverse Repurchase Agreements	$ 2,348,374	$ 2,822,912