Derivative Financial Instruments Derivative Financial Instruments (Schedule Of Fair Value Of Derivative Financial Instruments) (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	$ 47,550	$ 37,841	$ 37,239
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	47,698	36,921	34,990
Other Assets
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	62,984	47,964	51,529
Other Assets | Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	688	1,442	2,668
Other Assets | Designated as Hedging Instrument | Interest Rate Contract | Cash Flow Hedging
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	668	1,390	2,578
Other Assets | Designated as Hedging Instrument | Interest Rate Contract | Fair Value Hedging
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	20	52	90
Other Assets | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	62,296	46,522	48,861
Other Assets | Not Designated as Hedging Instrument | Interest Rate Contract
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	46,862	36,399	34,571
Other Assets | Not Designated as Hedging Instrument | Interest Rate Lock Commitments
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	15,296	10,028	13,658
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	23	625
Other Assets | Not Designated as Hedging Instrument | Foreign Exchange Contract
Derivative [Line Items]
Derivative Assets, Fair Value, Amount not Offset Against Collateral	138	72	7
Other Liabilities
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	55,225	41,180	37,797
Other Liabilities | Designated as Hedging Instrument
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	1,867	1,994	2,893
Other Liabilities | Designated as Hedging Instrument | Interest Rate Contract | Cash Flow Hedging
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	1,867	1,994	2,892
Other Liabilities | Designated as Hedging Instrument | Interest Rate Contract | Fair Value Hedging
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	0	0	1
Other Liabilities | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	53,358	39,186	34,904
Other Liabilities | Not Designated as Hedging Instrument | Interest Rate Contract
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	45,831	34,927	32,097
Other Liabilities | Not Designated as Hedging Instrument | Interest Rate Lock Commitments
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	0	20	115
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	7,410	4,239	2,688
Other Liabilities | Not Designated as Hedging Instrument | Foreign Exchange Contract
Derivative [Line Items]
Derivative Liabilities, Fair Value, Amount Not Offset Against Collateral	$ 117	$ 0	$ 4