Earnings Per Share (Schedule of Anti-Dilutive Securities of Common Shares) (Details) - shares shares in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total anti-dilutive securities		2,379	3,423	2,380	3,423
Share Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total anti-dilutive securities	[1]	899	1,924	897	1,924
Operating Partnership Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total anti-dilutive securities		1,480	1,499	1,483	1,499

[1] Exclusion results as exercise prices were greater than the average market price for each respective period.