Parent Company Only Financial Information - Summary of Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
ASSETS
Cash	$ 48,561	$ 45,620
Other assets	95,651	54,223
TOTAL ASSETS	2,268,940	2,173,929
LIABILITIES AND SHAREHOLDERS' EQUITY
Subordinated debt	53,610	53,610
Other liabilities	9,371	9,009
Shareholders' equity	198,604	165,546	170,077	166,299
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	2,268,940	2,173,929
Parent Company [Member]
ASSETS
Cash	919	4,067
Securities purchased under agreement to resell with subsidiary bank, maturing within 30 days	792	2,922
Investment in subsidiaries	250,033	212,182
Other assets	493	13
TOTAL ASSETS	252,237	219,184
LIABILITIES AND SHAREHOLDERS' EQUITY
Subordinated debt	53,610	53,610
Other liabilities	23	28
Shareholders' equity	198,604	165,546
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 252,237	$ 219,184