Derivative Instruments and Hedging Activities - Consolidated Statements of Financial Condition Related to Fair Value of Derivative Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Derivatives Designated as Hedging Instruments [Member]
Derivative [Line Items]
Notional Amount, Fair Value	$ 1,140,500	$ 1,191,591
Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedge Interest Rate Caps and Swaps [Member]
Derivative [Line Items]
Notional Amount, Fair Value	1,007,000	1,007,000
Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedge Interest Rate Swaps [Member]
Derivative [Line Items]
Notional Amount, Fair Value	133,500	184,591
Derivatives Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Notional Amount, Fair Value	389,197	306,616
Derivatives Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Notional Amount, Fair Value	373,745	259,832
Derivatives Not Designated as Hedging Instrument [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Notional Amount, Fair Value	15,452	46,784
Other Assets [Member] | Derivatives Designated as Hedging Instruments [Member]
Derivative [Line Items]
Asset Derivatives, Fair Value	6,357	9,982
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	3,647	9,883
Other Assets [Member] | Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedge Interest Rate Swaps [Member]
Derivative [Line Items]
Asset Derivatives, Fair Value	2,710	99
Other Assets [Member] | Derivatives Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset Derivatives, Fair Value	8,142	5,140
Other Assets [Member] | Derivatives Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Asset Derivatives, Fair Value	8,114	4,823
Other Assets [Member] | Derivatives Not Designated as Hedging Instrument [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Asset Derivatives, Fair Value	28	317
Other Liabilities [Member] | Derivatives Designated as Hedging Instruments [Member]
Derivative [Line Items]
Liability Derivatives, Fair Value	18,477	15,616
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	16,935	10,925
Other Liabilities [Member] | Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedge Interest Rate Swaps [Member]
Derivative [Line Items]
Liability Derivatives, Fair Value	1,542	4,691
Other Liabilities [Member] | Derivatives Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Liability Derivatives, Fair Value	8,189	4,970
Other Liabilities [Member] | Derivatives Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Liability Derivatives, Fair Value	8,105	4,823
Other Liabilities [Member] | Derivatives Not Designated as Hedging Instrument [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Liability Derivatives, Fair Value	$ 84	$ 147