Goodwill and Other Intangible Assets - Summary of Core Deposit Intangibles (Detail) - Core deposit intangibles [Member] $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($)
Finite-Lived Intangible Assets [Line Items]
Core deposit intangibles, Beginning balance	$ 10,120
Core deposit intangibles, Reductions/Amortization	0
Core deposit intangibles, Additions	2,046
Core deposit intangibles, Ending balance	8,074
Accumulated amortization, Beginning balance	(2,838)
Accumulated amortization, Reductions/Amortization	(658)
Accumulated amortization, Additions	0
Accumulated amortization, Ending balance	(2,180)
Core deposit intangibles, net, Beginning balance	7,282
Core deposit intangibles, net, Reductions/Amortization	(658)
Core deposit intangibles, net, Additions	2,046
Core deposit intangibles, net, Ending balance	$ 5,894