Derivative Financial Instruments (Derivatives not Designated as Hedging Instruments, Effect in Statements of Income) (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income	$ 2,358	$ 3,223
Interest rate swaps with customers [Member] | Loan related derivative income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income	(40,822)	(30,231)
Mirror swaps with counterparties [Member] | Loan related derivative income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income	41,122	30,683
Risk participation agreements [Member] | Loan related derivative income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income	1	15
Interest rate lock commitments [Member] | Mortgage banking revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income	(934)	(4,529)
Forward sale commitments [Member] | Mortgage banking revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income	$ 2,991	$ 7,285