Commitments and Contingencies - Consolidated Statements of Financial Condition Related to Fair Value of Derivative Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Other Assets [Member] | Derivatives designated as hedging Instruments [Member]
Derivative [Line Items]
Asset Derivatives, Fair Value	$ 675	$ 1,146
Other Assets [Member] | Derivatives designated as hedging Instruments [Member] | Cash flow hedge interest rate caps and swaps [Member]
Derivative [Line Items]
Asset Derivatives, Fair Value	23	294
Other Assets [Member] | Derivatives designated as hedging Instruments [Member] | Fair value hedge interest rate swaps [Member]
Derivative [Line Items]
Asset Derivatives, Fair Value	652	852
Other Assets [Member] | Derivatives not designated as hedging instrument [Member]
Derivative [Line Items]
Asset Derivatives, Fair Value	7,241	4,065
Other Assets [Member] | Derivatives not designated as hedging instrument [Member] | Interest rate swaps [Member]
Derivative [Line Items]
Asset Derivatives, Fair Value	7,002	4,065
Other Assets [Member] | Derivatives not designated as hedging instrument [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Asset Derivatives, Fair Value	239
Other Liabilities [Member] | Derivatives designated as hedging Instruments [Member]
Derivative [Line Items]
Liability Derivatives, Fair Value	19,395	17,789
Other Liabilities [Member] | Derivatives designated as hedging Instruments [Member] | Cash flow hedge interest rate caps and swaps [Member]
Derivative [Line Items]
Liability Derivatives, Fair Value	17,198	15,649
Other Liabilities [Member] | Derivatives designated as hedging Instruments [Member] | Fair value hedge interest rate swaps [Member]
Derivative [Line Items]
Liability Derivatives, Fair Value	2,197	2,140
Other Liabilities [Member] | Derivatives not designated as hedging instrument [Member]
Derivative [Line Items]
Liability Derivatives, Fair Value	7,199	4,065
Other Liabilities [Member] | Derivatives not designated as hedging instrument [Member] | Interest rate swaps [Member]
Derivative [Line Items]
Liability Derivatives, Fair Value	6,999	4,065
Other Liabilities [Member] | Derivatives not designated as hedging instrument [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Liability Derivatives, Fair Value	$ 200