Summary of Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016
Revenues included in Discontinued Operations	$ 264,749
Net income (loss) attributable to common stockholders	85,138	$ 59,666	$ 48,368	$ (33,223)	$ 55,868	$ 5,305	$ 34,810	$ 47,877
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Nonredeemable	171	132	104	(19)	92	16	64	85
Net Income (Loss) Allocated to General Partners	$ 85,309	$ 59,798	$ 48,472	$ (33,242)	$ 55,960	$ 5,321	$ 34,874	$ 47,962
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.50	$ 0.35	$ 0.28	$ (0.26)	$ 0.53	$ 0.05	$ 0.36	$ 0.49
Earnings Per Share, Diluted	$ 0.50	$ 0.35	$ 0.28	$ (0.26)
Income (Loss) from Continuing Operations, Per Diluted Share					$ 0.53	$ 0.05	$ 0.35	$ 0.49
Scenario, Previously Reported [Member]
Revenues included in Discontinued Operations		$ 262,141	$ 261,305	$ 196,131	$ 159,561	$ 152,769	$ 152,413	$ 149,628