CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Shares	Cumulative Common Distributions	Additional Paid in Capital	Cumulative Net Income Available for Common Shareholders	Cumulative Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2019		164,563,034
Beginning balance at Dec. 31, 2019	$ 2,505,878	$ 1,646	$ (5,534,942)	$ 4,547,529	$ 3,491,645	$ 0
Increase (Decrease) in Shareholders' Equity
Net loss	(33,650)				(33,650)
Share grants (in shares)		6,000
Share grants	602			602
Share repurchases (in shares)		(2,637)
Share repurchases	(55)			(55)
Distributions to common shareholders	(90,509)		(90,509)
Ending balance (in shares) at Mar. 31, 2020		164,566,397
Ending balance at Mar. 31, 2020	2,382,266	$ 1,646	(5,625,451)	4,548,076	3,457,995	0
Beginning balance (in shares) at Dec. 31, 2020		164,823,833
Beginning balance at Dec. 31, 2020	2,102,790	$ 1,648	(5,628,746)	4,550,385	3,180,263	(760)
Increase (Decrease) in Shareholders' Equity
Net loss	(194,990)				(194,990)
Share grants	380			380
Distributions to common shareholders	(1,648)		(1,648)
Ending balance (in shares) at Mar. 31, 2021		164,823,833
Ending balance at Mar. 31, 2021	$ 1,906,532	$ 1,648	$ (5,630,394)	$ 4,550,765	$ 2,985,273	$ (760)