Summary of Significant Accounting Policies (Computation of Anti-Dilutive Common Share) (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	$ 3,089	$ 6,404	$ 2,627
Weighted Average Limited Partnership Units Outstanding, Basic	3,481	3,582	4,308
Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	175	997	1,210
Participating Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	0	0	3,844