Earnings Per Share (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Weighted-average shares:
Common shares outstanding	78,544,380	70,349,265	71,462,264	71,248,765
Restricted common shares	669,489	571,326	562,612	596,749
Total Weighted Average Shares	79,213,869	70,920,591	72,024,876	71,845,514
Percentage of weighted-average shares:
Common shares outstanding	99.15%	99.19%	99.22%	99.17%
Restricted common shares	0.85%	0.81%	0.78%	0.83%
Total	100.00%	100.00%	100.00%	100.00%