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, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Net income	$ 328,040	$ 271,481	$ 388,404	$ 604,152
Allocation to Noncontrolling Interests – Operating Partnership	(10,913)	(9,713)	(13,056)	(21,248)
Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties	(741)	(880)	(1,423)	(13,410)
Preferred distributions	(772)	(772)	(1,545)	(1,545)
Net income available to Common Shares	315,614	260,116	372,380	567,949
Numerator for net income per share – diluted	$ 326,527	$ 269,829	$ 385,436	$ 589,197
Weighted average Common Shares outstanding	373,812	371,795	373,050	371,689
OP Units	12,044	13,023	12,544	13,013
Dilutive Securities Options	1,964	1,095	1,773	1,570
Denominator for net income per share – diluted	387,820	385,913	387,367	386,272
Net income per share – basic	$ 0.84	$ 0.70	$ 1.00	$ 1.53
Net income per share – diluted	$ 0.84	$ 0.70	$ 1.00	$ 1.53