Derivative Financial Instruments (Schedule of Notional Amounts and Estimated Fair Values of Interest Rate Derivative Contracts Outstanding) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Designated as Hedging Instrument [Member] | Financial Institution Counterparties Loan Lease Interest Rate Swaps Assets [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	$ 50,965	$ 14,748
Estimated Fair Value	1,386	24
Designated as Hedging Instrument [Member] | Financial Institution Counterparties Loan Lease Interest Rate Swaps Liabilities [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	43,631	84,577
Estimated Fair Value	(4,191)	(7,186)
Designated as Hedging Instrument [Member] | Financial Institution Counterparties Interest Rate Swap On Junior Subordinated Deferrable Interest Debentures [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	0	120,000
Estimated Fair Value	0	(4,365)
Not Designated as Hedging Instrument [Member] | Financial Institution Counterparties Loan Lease Interest Rate Swaps Assets [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	195,234	0
Estimated Fair Value	9,573	0
Not Designated as Hedging Instrument [Member] | Financial Institution Counterparties Loan Lease Interest Rate Swaps Liabilities [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	626,980	797,311
Estimated Fair Value	(32,469)	(60,994)
Not Designated as Hedging Instrument [Member] | Financial Institution Counterparties Loan Lease Interest Rate Caps Assets [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	53,058	30,000
Estimated Fair Value	1,309	12
Not Designated as Hedging Instrument [Member] | Customer Counterparties Loan Lease Interest Rate Swaps Assets [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	626,980	797,311
Estimated Fair Value	32,426	60,854
Not Designated as Hedging Instrument [Member] | Customer Counterparties Loan Lease Interest Rate Swaps Liabilities [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	195,234	0
Estimated Fair Value	(9,573)	0
Not Designated as Hedging Instrument [Member] | Customer Counterparties Loan Lease Interest Rate Caps Liabilities [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	53,058	30,000
Estimated Fair Value	$ (1,309)	$ (12)