Net Income (Loss) Per Common Share (Computation of Anti-Dilutive Common Shares) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	$ 842	$ 0	$ 1,234	$ 0
Weighted Average Limited Partnership Units Outstanding	4,388	0	4,397	0
Anti-Dilutive [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	$ 0	$ (466)	$ 0	$ (1,277)
Weighted Average Limited Partnership Units Outstanding	0	4,569	0	5,160
Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	1,373	1,728	1,373	1,728
Participating Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	3,949	4,047	3,949	4,047