Commitments and Contingencies - Consolidated Statements of Financial Condition Related to Fair Value of Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Interest Rate Caps and Swaps [Member]
Derivative [Line Items]
Other Assets	$ 0	$ 0
Other Liabilities	50,752	33,239
Derivatives Designated as Hedging Instruments [Member]
Derivative [Line Items]
Notional Amount	1,040,209	1,140,406
Derivatives Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Notional Amount	727,572	419,706
Derivatives Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Notional Amount	654,134	378,849
Derivatives Not Designated as Hedging Instrument [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Notional Amount	73,438	40,857
Other Assets [Member] | Derivatives Designated as Hedging Instruments [Member]
Derivative [Line Items]
Other Assets	8,942	8,486
Other Assets [Member] | Derivatives Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Other Assets	24,832	12,501
Other Assets [Member] | Derivatives Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Other Assets	24,628	12,464
Other Assets [Member] | Derivatives Not Designated as Hedging Instrument [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Other Assets	204	37
Other Liabilities [Member] | Derivatives Designated as Hedging Instruments [Member]
Derivative [Line Items]
Other Liabilities	26,129	20,784
Other Liabilities [Member] | Derivatives Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Other Liabilities	24,715	12,546
Other Liabilities [Member] | Derivatives Not Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Other Liabilities	24,623	12,455
Other Liabilities [Member] | Derivatives Not Designated as Hedging Instrument [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Other Liabilities	92	91
Designated as Fair Value Hedge [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Notional Amount	133,209	133,406
Designated as Fair Value Hedge [Member] | Other Assets [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Other Assets	7,658	6,257
Designated as Fair Value Hedge [Member] | Other Liabilities [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Other Liabilities	1,306	1,482
Cash Flow Hedge [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Caps and Swaps [Member]
Derivative [Line Items]
Notional Amount	907,000	1,007,000
Cash Flow Hedge [Member] | Other Assets [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Caps and Swaps [Member]
Derivative [Line Items]
Other Assets	1,284	2,229
Cash Flow Hedge [Member] | Other Liabilities [Member] | Derivatives Designated as Hedging Instruments [Member] | Interest Rate Caps and Swaps [Member]
Derivative [Line Items]
Other Liabilities	$ 24,823	$ 19,302