Derivative Instruments and Hedging Activities - Fair Value of Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Assets, Fair Value	$ 0	$ 0
Derivative Liabilities, Fair Value	27,586	13,932
Other Assets | Derivative Designated as Cash Flow Hedges | Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Assets, Fair Value	0	0
Other Assets | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Assets, Fair Value	19,492	9,295
Other Assets | Not Designated as Hedging Instrument | Residential Mortgage Loan Commitments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Assets, Fair Value	157	45
Other Assets | Not Designated as Hedging Instrument | Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Assets, Fair Value	19,063	9,088
Other Assets | Not Designated as Hedging Instrument | Credit Contract
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Assets, Fair Value	272	162
Other Liabilities | Derivative Designated as Cash Flow Hedges | Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Liabilities, Fair Value	7,287	4,477
Other Liabilities | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Liabilities, Fair Value	20,337	9,455
Other Liabilities | Not Designated as Hedging Instrument | Residential Mortgage Loan Commitments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Liabilities, Fair Value	0	0
Other Liabilities | Not Designated as Hedging Instrument | Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Liabilities, Fair Value	20,299	9,455
Other Liabilities | Not Designated as Hedging Instrument | Credit Contract
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Liabilities, Fair Value	$ 38	$ 0