Derivative Instruments and Hedging Activities - Balance Sheet Disclosures (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Interest Rate Caps and Swaps
Derivative [Line Items]
Other Assets	$ 0	$ 0
Other Liabilities	23,113	41,911
Derivatives designated as hedging instruments:
Derivative [Line Items]
Other Assets	588	802
Other Liabilities	1,231	16,627
Notional Amount	714,944	714,999
Derivatives designated as hedging instruments: | Cash Flow Hedge | Interest Rate Caps and Swaps
Derivative [Line Items]
Other Assets	588	802
Other Liabilities	343	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	888	986
Notional Amount	7,944	7,999
Derivatives not designated as hedging instruments:
Derivative [Line Items]
Other Assets	24,878	28,253
Other Liabilities	22,000	27,450
Notional Amount	1,162,267	1,322,305
Derivatives not designated as hedging instruments: | Interest Rate Swaps
Derivative [Line Items]
Other Assets	24,817	25,285
Other Liabilities	21,882	25,284
Notional Amount	1,108,416	1,075,722
Derivatives not designated as hedging instruments: | Mortgage Banking Derivatives
Derivative [Line Items]
Other Assets	61	2,968
Other Liabilities	118	2,166
Notional Amount	$ 53,851	$ 246,583