Earnings Per Share and Earnings Per Unit - Computation of Net Income per Share Basic and Net Income per Share Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net income	$ 271,481	$ 321,299	$ 604,152	$ 430,556
Allocation to Noncontrolling Interests – Operating Partnership	(9,713)	(11,510)	(21,248)	(15,429)
Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties	(880)	(821)	(13,410)	(1,620)
Preferred distributions	(772)	(772)	(1,545)	(1,545)
Net income available to Common Shares	260,116	308,196	567,949	411,962
Numerator for net income per share – diluted	$ 269,829	$ 319,706	$ 589,197	$ 427,391
Weighted average Common Shares outstanding	371,795	370,342	371,689	369,952
OP Units	13,023	12,885	13,013	12,902
Dilutive Securities Options	1,095	2,880	1,570	2,790
Denominator for net income per share – diluted	385,913	386,107	386,272	385,644
Net income per share – basic	$ 0.70	$ 0.83	$ 1.53	$ 1.11
Net income per share – diluted	$ 0.70	$ 0.83	$ 1.53	$ 1.11