Net Income (Loss) Per Common Share (Computation of Anti-Dilutive Common Shares) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	$ 0	$ 0	$ 1,142	$ 0
Weighted Average Limited Partnership Units Outstanding	0	0	4,393	0
Anti-Dilutive [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	$ (92)	$ (459)	$ 0	$ (1,736)
Weighted Average Limited Partnership Units Outstanding	4,388	4,511	0	4,942
Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	1,373	1,763	1,373	1,763
Participating Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	3,866	4,045	3,866	4,045