Resale and Repurchase Agreements (Balance Sheet Offsetting) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Resale agreement [Member]
Balance Sheet Offsetting [Line Items]
Securities Purchased under Agreements to Resell, Gross	$ 450,000	$ 1,025,000
Securities Purchased under Agreements to Resell, Liability	0	(200,000)
Securities purchased under agreements to resell, net	450,000	825,000
Securities Purchased under Agreements to Resell, Not Subject to Master Netting Arrangement	0	0
Securities Purchased under Agreements to Resell, Collateral, Obligation to Return Securities	(450,000)	(825,000)
Securities Purchased under Agreements to Resell, Amount Offset Against Collateral	0	0
Repurchase agreement [Member]
Balance Sheet Offsetting [Line Items]
Securities Sold under Agreements to Repurchase, Gross	2,647,510	2,881,874
Securities Sold under Agreements to Repurchase, Asset	0	(200,000)
Securities sold under agreements to repurchase, net	2,647,510	2,681,874
Securities Sold under Agreements to Repurchase, Not Subject to Master Netting Arrangement	0	0
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	(2,647,510)	(2,681,874)
Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral	$ 0	$ 0