Derivative Financial Instruments (Schedule Of Fair Value Of Derivative Financial Instruments) (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Derivative [Line Items]
Derivative assets	$ 49,703	$ 56,394	$ 101,052
Derivative liabilities	37,651	39,839	100,912
Interest Rate Contract
Derivative [Line Items]
Derivative assets	46,647	49,213	89,036
Derivative liabilities	35,343	37,665	90,892
Designated as Hedging Instrument
Derivative [Line Items]
Derivative assets	10,718	10,239	12
Derivative liabilities	26	0	2,576
Designated as Hedging Instrument | Interest Rate Contract | Cash Flow Hedging
Derivative [Line Items]
Derivative assets	8,644	8,011	12
Derivative liabilities	0	0	1,577
Designated as Hedging Instrument | Interest Rate Contract | Fair Value Hedging
Derivative [Line Items]
Derivative assets	2,074	2,228	0
Derivative liabilities	26	0	999
Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative assets	38,985	46,155	101,040
Derivative liabilities	37,625	39,839	98,336
Not Designated as Hedging Instrument | Interest Rate Contract
Derivative [Line Items]
Derivative assets	35,929	38,974	89,024
Derivative liabilities	35,317	37,665	88,316
Not Designated as Hedging Instrument | Interest Rate Lock Commitments
Derivative [Line Items]
Derivative assets	2,875	4,265	11,435
Derivative liabilities	182	1,325	2,973
Not Designated as Hedging Instrument | Forward Commitments to Sell Mortgage Loans
Derivative [Line Items]
Derivative assets	78	2,037	0
Derivative liabilities	1,961	0	6,496
Not Designated as Hedging Instrument | Foreign Exchange Contract
Derivative [Line Items]
Derivative assets	103	879	581
Derivative liabilities	$ 165	$ 849	$ 551