Derivative Financial Instruments (Schedule Of Fair Value Of Derivative Financial Instruments) (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	$ 73,985	$ 42,779	$ 47,550
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	74,019	42,458	47,698
Other Assets
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	86,337	51,298	62,984
Other Assets | Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	64	269	688
Other Assets | Designated as Hedging Instrument | Interest Rate Contract | Cash Flow Hedging
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	64	242	668
Other Assets | Designated as Hedging Instrument | Interest Rate Contract | Fair Value Hedging
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	0	27	20
Other Assets | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	86,273	51,029	62,296
Other Assets | Not Designated as Hedging Instrument | Interest Rate Contract
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	73,921	42,510	46,862
Other Assets | Not Designated as Hedging Instrument | Interest Rate Lock Commitments
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	12,104	7,401	15,296
Other Assets | Not Designated as Hedging Instrument | Forward Commitments to Sell Mortgage Loans
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	0	745	0
Other Assets | Not Designated as Hedging Instrument | Foreign Exchange Contract
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	248	373	138
Other Liabilities
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	81,712	45,019	55,225
Other Liabilities | Designated as Hedging Instrument
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	1,256	989	1,867
Other Liabilities | Designated as Hedging Instrument | Interest Rate Contract | Cash Flow Hedging
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	586	846	1,867
Other Liabilities | Designated as Hedging Instrument | Interest Rate Contract | Fair Value Hedging
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	670	143	0
Other Liabilities | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	80,456	44,030	53,358
Other Liabilities | Not Designated as Hedging Instrument | Interest Rate Contract
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	72,763	41,469	45,831
Other Liabilities | Not Designated as Hedging Instrument | Interest Rate Lock Commitments
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	3,574	171	0
Other Liabilities | Not Designated as Hedging Instrument | Forward Commitments to Sell Mortgage Loans
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	3,857	2,275	7,410
Other Liabilities | Not Designated as Hedging Instrument | Foreign Exchange Contract
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	$ 262	$ 115	$ 117