Offsetting of Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financial derivatives–assets
Financial derivatives–assets, at fair value-	$ 131,472	$ 132,518
Financial Instruments Available for Offset	(30,342)	(53,229)
Cash Collateral (Received) Pledged	(44,255)	(32,044)
Net Amount	56,875	47,245
Reverse repurchase agreements
Reverse repurchase agreements	183,676	226,444
Financial Instruments Available for Offset	0	(152,946)
Cash Collateral (Received) Pledged	0	0
Net Amount	0	0
Repurchase agreements
Reverse repurchase agreements	(2,557,864)	(2,609,685)
Financial Instruments Available for Offset	0	152,946
Cash Collateral (Received) Pledged	15,278	20,267
Net Amount	0	0
Financial derivatives–liabilities
Financial derivatives–liabilities, at fair value-	(30,502)	(54,198)
Financial Instruments Available for Offset	30,342	53,229
Cash Collateral (Received) Pledged	129	534
Net Amount	(31)	(435)
Securities Collateral relating to Reverse Repurchase Agreements	3,200,000	3,200,000
Financial Derivatives - Assets
Financial derivatives–liabilities
Excess cash collateral	200	400
Derivative Asset, Fair Value of Collateral	0	0
Securities Purchased under Agreements to Resell [Member]
Financial derivatives–assets
Securities Purchased under Agreements to Resell, Fair Value of Collateral	(183,676)	(73,498)
Financial Derivatives - Liabilities
Reverse repurchase agreements
Derivative Liability, Fair Value of Collateral	0	0
Financial derivatives–liabilities
Excess cash collateral	1,100	1,800
Reverse repurchase agreements
Financial derivatives–liabilities
Securities Collateral relating to Reverse Repurchase Agreements	$ 2,542,586	$ 2,436,472