Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue
Real estate rental revenue		$ 73,227	$ 80,259	$ 222,889	$ 228,513
Expenses
Real estate expenses		28,672	30,692	84,196	84,969
Depreciation and amortization		30,470	37,340	89,789	97,441
General and administrative expenses		6,330	6,461	17,963	19,803
Real estate impairment		0	0	0	8,374
Expenses		65,472	74,493	191,948	210,587
Loss on sale of real estate		0	0	(7,539)	(1,046)
Real estate operating income		7,755	5,766	23,402	16,880
Other income (expense)
Interest expense		(8,711)	(14,198)	(28,307)	(41,946)
Gain on extinguishment of debt		0	0	262	0
Total other expense		(8,711)	(14,198)	(28,045)	(41,946)
Loss from continuing operations		(956)	(8,432)	(4,643)	(25,066)
Discontinued operations:
Income from operations of properties sold or held for sale		0	2,942	0	16,158
Gain on sale of real estate		0	339,024	0	339,024
Loss on extinguishment of debt		0	(764)	0	(764)
Income from discontinued operations		0	341,202	0	354,418
Net (loss) income		(956)	332,770	(4,643)	329,352
Less: Net income attributable to noncontrolling interests in subsidiaries		0	0	0	0
Net (loss) income attributable to the controlling interests		$ (956)	$ 332,770	$ (4,643)	$ 329,352
Basic net (loss) income attributable to the controlling interests per share:
Continuing operations, basic (in dollars per share)		$ (0.01)	$ (0.10)	$ (0.06)	$ (0.31)
Discontinued operations, basic (in dollars per share)		0	4.24	0	4.41
Basic net (loss) income attributable to the controlling interests per share (in dollars per share)	[1]	(0.01)	4.14	(0.06)	4.10
Diluted net (loss) income attributable to the controlling interests per share:
Continuing operations, diluted (in dollars per share)		(0.01)	(0.10)	(0.06)	(0.31)
Discontinued operations, diluted (in dollars per share)		0	4.24	0	4.41
Diluted net (loss) income attributable to the controlling interests per share (in dollars per share)	[1]	$ (0.01)	$ 4.14	$ (0.06)	$ 4.10
Weighted average shares outstanding - basic (in shares)		82,186	79,981	82,142	79,933
Weighted average shares outstanding - diluted (in shares)		82,186	79,981	82,142	79,933
Dividends declared per share (in dollars per share)		$ 0.30	$ 0.30	$ 0.90	$ 0.90
Revenue, type [Extensible List]		us-gaap:RealEstateMember	us-gaap:RealEstateMember	us-gaap:RealEstateMember	us-gaap:RealEstateMember
Expenses, type [Extensible List]		us-gaap:RealEstateMember	us-gaap:RealEstateMember	us-gaap:RealEstateMember	us-gaap:RealEstateMember

[1] Earnings per share may not sum due to rounding