Earnings per Share (Summary of Basic and Diluted Earnings per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings per Share
Net (loss) income available to common stockholders	$ (37,370)	$ 49,827	$ 219,165	$ 177,434
Weighted average shares outstanding-basic (shares)	270,214,413	208,421,470	253,377,527	208,173,995
Potentially dilutive common shares:
Unvested incentive units (shares)		181,064	103,159	142,670
Unvested restricted stock (shares)			273,755
Forward equity offering (shares)		1,013,970	2,087,607	705,720
Market performance-based awards (shares)		185,267	520,531	177,150
Weighted average shares/units outstanding-diluted (shares/units)	270,214,413	209,801,771	256,362,579	209,199,535
Earnings per unit:
Basic (in dollars per share)	$ (0.14)	$ 0.24	$ 0.86	$ 0.85
Diluted (in dollars per share)	$ (0.14)	$ 0.24	$ 0.85	$ 0.85