Derivatives (Effects of Derivative Instruments on the Statements of Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	$ 43,578	$ 30,219	$ 6,952
Derivatives Designated as Hedging Instruments [Member] | Other Noninterest Income [Member] | Customer and All Other Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	13,477	12,814	12,958
Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedge [Member] | Interest Income [Member] | Interest Rate Swaps - Variable Rate Loans [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	26,674	17,351	(4,255)
Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedging [Member] | Interest Income [Member] | Interest Rate Swaps - Securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	(640)	8	1
Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedging [Member] | Securities Transactions Net [Member] | Securities Termination [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	2,499
Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedging [Member] | Interest Expense [Member] | Brokered Deposits [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement		$ 46	$ (1,752)
Derivatives Not Designated as Hedging Instruments [Member] | Secondary Mortgage Market Operations [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative income reflected in income statement	$ 1,568