Derivative Instruments and Hedging Activities - Balance Sheet Disclosures (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Interest Rate Caps and Swaps
Derivative [Line Items]
Other Assets	$ 0	$ 0
Other Liabilities	23,737	41,911
Derivatives designated as hedging instruments:
Derivative [Line Items]
Other Assets	528	802
Other Liabilities	867	16,627
Notional Amount	714,889	714,999
Derivatives designated as hedging instruments: | Cash Flow Hedge | Interest Rate Caps and Swaps
Derivative [Line Items]
Other Assets	528	802
Other Liabilities	31	15,641
Notional Amount	707,000	707,000
Derivatives designated as hedging instruments: | Fair Value Hedge | Interest Rate Swaps
Derivative [Line Items]
Other Assets	0	0
Other Liabilities	836	986
Notional Amount	7,889	7,999
Derivatives not designated as hedging instruments:
Derivative [Line Items]
Other Assets	26,236	28,253
Other Liabilities	23,035	27,450
Notional Amount	1,376,841	1,322,305
Derivatives not designated as hedging instruments: | Interest Rate Swaps
Derivative [Line Items]
Other Assets	26,058	25,285
Other Liabilities	22,870	25,284
Notional Amount	1,288,274	1,075,722
Derivatives not designated as hedging instruments: | Mortgage banking derivatives
Derivative [Line Items]
Other Assets	178	2,968
Other Liabilities	165	2,166
Notional Amount	$ 88,567	$ 246,583