Derivative Instruments and Hedging Activities - Value of Derivative Assets and Derivative Liabilities (Detail) (Not Designated as Hedging Instruments [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Assets)	$ 13,698	$ 23,748
Fair value, Derivatives (included in Other Liabilities)	13,647	23,522
Other Assets [Member] | Interest Rate Swap Contracts-Commercial Loans [Member]
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Assets)	13,698	23,748
Notional amount, Derivatives (included in Other Assets)	261,754	227,532
Other Assets [Member] | Interest Rate Lock Commitments-Mortgage Loans [Member]
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Assets)	85	467
Notional amount, Derivatives (included in Other Assets)	3,989	14,287
Other Assets [Member] | Forward Sale Contracts-Mortgage Loans [Member]
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Assets)	34
Notional amount, Derivatives (included in Other Assets)	5,250
Other Liabilities [Member] | Interest Rate Swap Contracts-Commercial Loans [Member]
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Liabilities)	13,647	23,522
Notional amount, Derivatives (included in Other Liabilities)	261,754	227,532
Collateral posted, Derivatives (included in Other Liabilities)	12,611	19,595
Other Liabilities [Member] | Forward Sale Contracts-Mortgage Loans [Member]
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Liabilities)		48
Notional amount, Derivatives (included in Other Liabilities)		$ 14,100