Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Statement Of Financial Position [Abstract]
Amortized cost of securities available for sale, at estimated fair value	$ 550,785	$ 444,243
Fair value of securities held to maturity, at amortized cost	6,556	10,825
Allowance for loan losses	$ 25,990	$ 26,612
Preferred Stock, par value	$ 0.01	$ 0.01
Preferred Stock, shares authorized	15,000,000	15,000,000
Preferred Stock, shares outstanding	0	0
Common stock, par value	$ 0.20	$ 0.20
Common stock, shares authorized	25,000,000	25,000,000
Common stock, shares outstanding	19,935,559	19,761,426
Treasury stock, shares	1,299,414	1,299,414