Summary of Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017
Revenues included in Discontinued Operations	$ 284,560	$ 278,310	$ 281,412	$ 276,693	$ 264,749	$ 262,141	$ 261,305	$ 196,131
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Nonredeemable	167	147	100	111	171	132	104	(19)
Net Income (Loss) Allocated to General Partners	$ 79,071	$ 69,869	$ 47,941	$ 52,771	$ 85,309	$ 59,798	$ 48,472	$ (33,242)
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.47	$ 0.41	$ 0.28	$ 0.31	$ 0.50	$ 0.35	$ 0.28	$ (0.26)
Earnings Per Share, Diluted	$ 0.46	$ 0.41	$ 0.28	$ 0.31
Income (Loss) from Continuing Operations, Per Diluted Share					$ 0.50	$ 0.35	$ 0.28	$ (0.26)