Fair Value - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired loans, recorded investment	$ 17,655		$ 18,308
Impaired loans allowance	2,227		1,882
Collateral Dependent Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired loans, recorded investment	8,059		8,161
Impaired loans allowance	1,861		1,455
Impaired loans, additional provisions	$ 350	$ 201