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		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net income	$ 95,365	$ 277,846	$ 699,517	$ 708,402
Allocation to Noncontrolling Interests – Operating Partnership	(3,376)	(9,910)	(24,624)	(25,339)
Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties	(703)	(830)	(14,113)	(2,450)
Preferred distributions	(773)	(773)	(2,318)	(2,318)
Net income available to Common Shares	90,513	266,333	658,462	678,295
Numerator for net income per share – diluted	$ 93,889	$ 276,243	$ 683,086	$ 703,634
Weighted average Common Shares outstanding	371,869	370,768	371,749	370,227
OP Units	13,002	12,941	13,010	12,915
Dilutive Securities Options	781	3,187	1,214	3,035
Denominator for net income per share – diluted	385,652	386,896	385,973	386,177
Net income per share – basic	$ 0.24	$ 0.72	$ 1.77	$ 1.83
Net income per share – diluted	$ 0.24	$ 0.71	$ 1.77	$ 1.82