Derivative Financial Instruments - Summary of Fair Value of Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Derivative [Line Items]
Total derivative assets	$ 17,267	$ 17,701
Total derivative liabilities	17,368	23,574
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Total derivative assets	2,962	3,056
Total derivative liabilities	8,266	11,582
Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Total derivative assets	2,962	3,056
Total derivative liabilities	8,266	11,582
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Total derivative assets	14,305	14,645
Total derivative liabilities	9,102	11,992
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Total derivative assets	12,893	11,903
Total derivative liabilities	9,096	11,992
Not Designated as Hedging Instrument [Member] | Mortgage Contracts [Member]
Derivative [Line Items]
Total derivative assets	1,406	$ 2,742
Not Designated as Hedging Instrument [Member] | Foreign Currency Contracts [Member]
Derivative [Line Items]
Total derivative assets	6
Total derivative liabilities	$ 6