Fair Value of Financial Instruments - Schedule of Financial Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Collateral dependent impaired loans	$ 93,602	$ 30,204
Other real estate owned	17,206	29,715
Total nonrecurring fair value measurements	110,808	59,919
Level 2 [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Collateral dependent impaired loans	93,602	30,204
Total nonrecurring fair value measurements	93,602	30,204
Level 3 [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Other real estate owned	17,206	29,715
Total nonrecurring fair value measurements	$ 17,206	$ 29,715