Goodwill and Other Intangible Assets - Summary of Core Deposit Intangibles (Detail) (USD $) In Thousands, unless otherwise specified			9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Core deposit intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Core deposit intangibles, Beginning balance			$ 1,460
Core deposit intangibles, Reductions/Amortization			0
Core deposit intangibles, Additions			0
Core deposit intangibles, Ending balance			1,460
Accumulated amortization, Beginning balance			(734)
Accumulated amortization, Reductions/Amortization			0
Accumulated amortization, Additions			(157)
Accumulated amortization, Ending balance			(577)
Core deposit intangibles, net, Beginning balance	726	883	726
Core deposit intangibles, net, Reductions/Amortization			0
Core deposit intangibles, net, Additions			(157)
Core deposit intangibles, net, Ending balance	$ 726	$ 883	$ 883