Short-Term Borrowings (Short-Term Borrowings) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Short-Term Debt [Line Items]
Amount outstanding at period end	$ 3,519,497		$ 1,871,271
Federal Funds Purchased [Member]
Short-Term Debt [Line Items]
Amount outstanding at period end	$ 350		$ 1,850
Weighted-average interest at period end	4.40%		3.90%
Average amount outstanding during period	$ 8,411	$ 2,387
Maximum amount at any month end during period	$ 1,850	$ 2,350
Weighted-average interest rate during period	5.11%	0.28%
Securities Sold under Agreements to Repurchase [Member]
Short-Term Debt [Line Items]
Amount outstanding at period end	$ 419,147		$ 444,421
Weighted-average interest at period end	0.95%		0.53%
Average amount outstanding during period	$ 445,773	$ 587,508
Maximum amount at any month end during period	$ 499,011	$ 640,592
Weighted-average interest rate during period	0.69%	0.06%
FHLB Borrowings [Member]
Short-Term Debt [Line Items]
Amount outstanding at period end	$ 3,100,000	$ 3,100,000	$ 1,425,000
Weighted-average interest at period end	4.99%		4.70%
Average amount outstanding during period	$ 1,644,444	1,100,011
Maximum amount at any month end during period	$ 3,100,000	$ 1,100,000
Weighted-average interest rate during period	4.74%	0.49%