Subsequent Event - Additional Information (Detail) (Coastal Bankshares, Inc. [Member], USD $)		0 Months Ended
	Dec. 31, 2013	Mar. 10, 2014 Subsequent Event [Member] Location	Feb. 28, 2014 Subsequent Event [Member]
Subsequent Event [Line Items]
Number of banking locations		6
Assets acquired through merger	$ 433,000,000
Loans acquired through merger	295,000,000
Deposits acquired through merger	364,000,000
Share issued as consideration		0.4671
Approximate transaction value			$ 37,300,000
Percentage of tangible book value			169.00%