Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Numerator for basic and diluted earnings per share - net income (loss) attributable to common stockholders		$ 26,257	$ 179,246	$ 97,803	$ 489,530
Adjustment for net income (loss) attributable to OP units		(873)	(1,366)	(2,225)	(2,754)
Numerator for diluted earnings per share		$ 25,384	$ 177,880	$ 95,578	$ 486,776
Denominator for basic earnings per share - weighted average shares (in shares)		417,452,000	417,084,000	417,360,000	413,696,000
Effect of dilutive securities:
Non-vested restricted shares (in shares)		438,000	619,000	430,000	661,000
Redeemable op units (in shares)		1,396,000	1,396,000	1,396,000	1,396,000
Employee stock purchase program (in shares)		19,000	22,000	19,000	22,000
Dilutive potential common shares (in shares)		1,853,000	2,037,000	1,845,000	2,079,000
Denominator for diluted earnings per share - adjusted weighted average shares (in shares)		419,305,000	419,121,000	419,205,000	415,775,000
Basic earnings per share (in dollars per share)		$ 0.06	$ 0.43	$ 0.23	$ 1.18
Diluted earnings per share (in dollars per share)	[1]	$ 0.06	$ 0.42	$ 0.23	$ 1.17
Forward sales agreement
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)				13,052,375

[1] Includes adjustment to the numerator for income (loss) attributable to OP unitholders.