Goodwill and Other Intangible Assets - Schedule of Other Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	$ 15,700	$ 6,345
Core deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	12,833	3,005
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	2,463	2,828
Non-compete agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	$ 404	$ 512