Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Time certificates of deposit least amount	$ 100,000	$ 100,000
Securities held to maturity, fair value	$ 346,455,000	$ 185,824,000
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	23,805,984	22,774,009
Common stock, shares outstanding	23,805,984	22,774,009
Common stock, unvested restricted Stock awards	268,290	264,124
Shares held in rabbit trust at cost	178,765	179,814