Goodwill and Other Intangible Assets - Summary of Core Deposit Intangibles (Detail) - Core deposit intangibles [Member]
$ in Thousands
12 Months Ended
Dec. 31, 2015
USD ($)
Finite-Lived Intangible Assets [Line Items]  
Core deposit intangibles, Beginning balance $ 8,074
Core deposit intangibles, Reductions/Amortization 0
Core deposit intangibles, Additions 0
Core deposit intangibles, Ending balance 8,074
Accumulated amortization, Beginning balance (1,023)
Accumulated amortization, Reductions/Amortization 0
Accumulated amortization, Additions (1,157)
Accumulated amortization, Ending balance (2,180)
Core deposit intangibles, net, Beginning balance 7,051
Core deposit intangibles, net, Reductions/Amortization 0
Core deposit intangibles, net, Additions (1,157)
Core deposit intangibles, net, Ending balance $ 5,894