Derivative Instruments (Schedule Of Fair Values Of Derivative Instruments) (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative Assets	[1]	$ 250,450	$ 105,674
Derivative Liabilities	[1]	(20,443)	(10,219)
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		151,046	67,192
Derivative Liabilities		0	0
Designated as Hedging Instrument [Member] | Interest Rate Floor [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		151,046	67,192
Derivative Liabilities		0	0
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		99,404	38,482
Derivative Liabilities		(20,443)	(10,219)
Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		98,886	37,774
Derivative Liabilities		(19,394)	(9,916)
Not Designated as Hedging Instrument [Member] | Interest Rate Caps [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		31	4
Derivative Liabilities		(31)	(4)
Not Designated as Hedging Instrument [Member] | Credit Risk Participation Agreements [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		424	140
Derivative Liabilities		(981)	(230)
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		63	97
Derivative Liabilities		(37)	(32)
Not Designated as Hedging Instrument [Member] | Mortgage Loan Commitments [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		0	459
Derivative Liabilities		0	0
Not Designated as Hedging Instrument [Member] | Mortgage Loan Forward Sale Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		0	6
Derivative Liabilities		0	(2)
Not Designated as Hedging Instrument [Member] | Forward TBA Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		0	2
Derivative Liabilities		$ 0	$ (35)

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