Goodwill and Other Intangible Assets - Schedule of Other Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	$ 6,539	$ 8,147
Core deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	4,115	5,296
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	1,944	2,262
Non-compete agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	$ 480	$ 589