Derivative Financial Instruments - Fair Value of Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Fair Values Of Financial Assets And Liabilities Including Derivative Financial Instruments [Line Items]
Total Asset Derivatives	$ 4,927	$ 2,424
Total Liability Derivatives	7,985	4,923
Derivatives Designated as Hedging Instruments [Member]
Fair Values Of Financial Assets And Liabilities Including Derivative Financial Instruments [Line Items]
Total Asset Derivatives	4,283	1,782
Total Liability Derivatives	7,985	4,923
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Contracts One [Member] | Other Liabilities [Member]
Fair Values Of Financial Assets And Liabilities Including Derivative Financial Instruments [Line Items]
Total Liability Derivatives	4,283	1,782
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Contracts Two [Member] | Other Liabilities [Member]
Fair Values Of Financial Assets And Liabilities Including Derivative Financial Instruments [Line Items]
Total Liability Derivatives	3,702	3,141
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Contracts Two [Member] | Other Assets [Member]
Fair Values Of Financial Assets And Liabilities Including Derivative Financial Instruments [Line Items]
Total Asset Derivatives	4,283	1,782
Derivatives Not Designated as Hedging Instruments [Member]
Fair Values Of Financial Assets And Liabilities Including Derivative Financial Instruments [Line Items]
Total Asset Derivatives	644	642
Derivatives Not Designated as Hedging Instruments [Member] | Mortgage Loan Contracts [Member] | Other Assets [Member]
Fair Values Of Financial Assets And Liabilities Including Derivative Financial Instruments [Line Items]
Total Asset Derivatives	$ 644	$ 642