Earnings Per Share (Schedule Showing Calculation Of Basic And Diluted Earnings Per Share) (Details) (USD $)	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011
Earnings Per Share, Basic And Diluted, By Common Class, Including Two Class Method [Line Items]
Income available to common shareholders	$ 19,393,000		$ 14,647,000
Distributed and undistributed earnings to unvested restricted stock	(374,000)		(306,000)
Distributed and undistributed earnings to common shareholders - Basic	19,019,000	[1]	14,341,000	[1]
Undistributed earnings reallocated to unvested restricted stock	10,000		15,000
Distributed and undistributed earnings to common shareholders - Diluted	19,029,000		14,356,000
Weighted average shares outstanding- Basic	29,384,220	[2]	26,845,124	[2]
Weighted average shares outstanding- Diluted	28,928,276		26,560,866
Earnings per common share - Basic	$ 0.66	[1]	$ 0.54	[1]
Earnings per common share - Diluted	$ 0.66		$ 0.54
Distributed earnings	9,842,000		8,983,000
Distributed earnings, per weighted average share	$ 0.34		$ 0.34
Undistributed earnings	9,177,000		5,358,000
Undistributed earnings, per weighted average share	$ 0.32		$ 0.20
Weighted average basic shares outstanding, unvested restricted stock	535,005		492,956
Unvested Restricted Stock [Member]
Earnings Per Share, Basic And Diluted, By Common Class, Including Two Class Method [Line Items]
Earnings per common share - Basic	$ 0.70	[3]	$ 0.62	[3]
Earnings per common share - Diluted	$ 0.68		$ 0.59
Distributed earnings	194,000		192,000
Distributed earnings, per weighted average share	$ 0.36		$ 0.39
Undistributed earnings	$ 180,000		$ 114,000
Undistributed earnings, per weighted average share	$ 0.34		$ 0.23

[1] Total earnings available to common shareholders include distributed earnings of $9,842,000, or $0.34 per weighted average share, and undistributed earnings of $9,177,000, or $0.32 per weighted average share for the three months ended March 31, 2012. Total earnings available to common shareholders include distributed earnings of $8,983,000, or $0.34 per weighted average share, and undistributed earnings of $5,358,000, or $0.20 per weighted average share for the three months ended March 31, 2011.

[2] Weighted average basic shares outstanding include 535,005 and 492,956 shares of unvested restricted stock for the three months ended March 31, 2012 and 2011, respectively.

[3] Total earnings available to unvested restricted stock include distributed earnings of $194,000, or $0.36 per weighted average share, and undistributed earnings of $180,000, or $0.34 per weighted average share for the three months ended March 31, 2012. Total earnings available to unvested restricted stock include distributed earnings of $192,000, or $0.39 per weighted average share, and undistributed earnings of $114,000, or $0.23 per weighted average share for the three months ended March 31, 2011.