Derivative Instruments (Schedule Of Fair Values Of Derivative Instruments) (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative Assets	[1]	$ 147,850	$ 105,674
Derivative Liabilities	[1]	(20,370)	(10,219)
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		47,306	67,192
Derivative Liabilities		0	0
Designated as Hedging Instrument [Member] | Interest Rate Floor [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		47,306	67,192
Derivative Liabilities		0	0
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		100,544	38,482
Derivative Liabilities		(20,370)	(10,219)
Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		96,866	37,774
Derivative Liabilities		(18,981)	(9,916)
Not Designated as Hedging Instrument [Member] | Interest Rate Caps [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		1	4
Derivative Liabilities		(1)	(4)
Not Designated as Hedging Instrument [Member] | Credit Risk Participation Agreements [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		440	140
Derivative Liabilities		(1,185)	(230)
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		32	97
Derivative Liabilities		(50)	(32)
Not Designated as Hedging Instrument [Member] | Mortgage Loan Commitments [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		3,137	459
Derivative Liabilities		0	0
Not Designated as Hedging Instrument [Member] | Mortgage Loan Forward Sale Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		29	6
Derivative Liabilities		(6)	(2)
Not Designated as Hedging Instrument [Member] | Forward TBA Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		39	2
Derivative Liabilities		$ (147)	$ (35)

[1] * The fair value of each class of derivative is shown in Note 11.