Summary of Significant Accounting Policies (Computation of Anti-Dilutive Common Share) (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	$ 6,404	$ 2,627	$ 2,094
Weighted Average Limited Partnership Units Outstanding, Basic	3,582	4,308	4,392
Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	997	1,210	1,373
Participating Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	0	3,844	3,871