Derivative Financial Instruments (Schedule Of Fair Value Of Derivative Financial Instruments) (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Derivative [Line Items]
Derivative assets	$ 108,784	$ 73,172	$ 92,156
Derivative liabilities	136,312	68,088	69,364
Interest Rate Contract
Derivative [Line Items]
Derivative assets	104,562	68,425	86,435
Derivative liabilities	131,035	62,571	64,368
Designated as Hedging Instrument
Derivative [Line Items]
Derivative assets	1,033	8,906	21,767
Derivative liabilities	27,549	3,412	280
Designated as Hedging Instrument | Interest Rate Contract | Cash Flow Hedging
Derivative [Line Items]
Derivative assets	616	6,270	16,059
Derivative liabilities	20,851	1,656	0
Designated as Hedging Instrument | Interest Rate Contract | Fair Value Hedging
Derivative [Line Items]
Derivative assets	417	2,636	5,708
Derivative liabilities	6,698	1,756	280
Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative assets	107,751	64,266	70,389
Derivative liabilities	108,763	64,676	69,084
Not Designated as Hedging Instrument | Interest Rate Contract
Derivative [Line Items]
Derivative assets	103,529	59,519	64,668
Derivative liabilities	103,486	59,159	64,088
Not Designated as Hedging Instrument | Interest Rate Lock Commitments
Derivative [Line Items]
Derivative assets	4,054	3,405	4,543
Derivative liabilities	96	2,694	2,512
Not Designated as Hedging Instrument | Forward Commitments to Sell Mortgage Loans
Derivative [Line Items]
Derivative assets	96	0	7
Derivative liabilities	5,112	1,486	1,376
Not Designated as Hedging Instrument | Foreign Exchange Contract
Derivative [Line Items]
Derivative assets	72	1,342	1,171
Derivative liabilities	$ 69	$ 1,337	$ 1,108