Earnings Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Weighted-average shares:
Common shares outstanding	78,237,199	77,989,933	78,197,091	78,230,011
Restricted common shares	569,617	680,249	569,453	646,299
Total Weighted Average Shares	78,806,816	78,670,182	78,766,544	78,876,310
Percentage of weighted-average shares:
Common shares outstanding	99.28%	99.14%	99.28%	99.18%
Restricted common shares	0.72%	0.86%	0.72%	0.82%
Total	100.00%	100.00%	100.00%	100.00%