Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Statement of Financial Position [Abstract]
Securities held to maturity, fair value	$ 185,824,000	$ 211,494,000
Time certificates of deposit least amount	$ 100,000	$ 100,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	22,774,009	21,499,768
Common stock, shares outstanding	22,774,009	21,499,768
Common stock, unvested restricted Stock awards	264,124	235,540
Shares held in rabbit trust at cost	179,814	180,058