Investments - Summary of Real Estate and Loan Activity (Details) $ in Thousands	1 Months Ended	8 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($) property	Aug. 31, 2019 USD ($) property	Sep. 30, 2019 USD ($) property	Dec. 31, 2018 USD ($)
Number of Properties
Ending balance | property	11		11
Dollar Amount of Investments
Less: accumulated depreciation				$ (459,615)
Net investments	$ 25,700		$ 25,700	$ 2,054,537
Wholly Owned Properties
Number of Properties
Beginning balance | property		876	876
Acquisitions | property		0
Net Adjustments to Realizable Value | property	0
Dispositions of real estate (in properties) | property	(765)	(100)
Impairments (in properties) | property		0
Write-off of intangibles (in properties) | property		0
Ending balance | property	11	776	11
Dollar Amount of Investments
Gross balance, December 31, 2018		$ 2,531,248	$ 2,531,248
Acquisitions/improvements		5,891
Net Adjustments to Realizable Value	$ 667,006
Dispositions of real estate		(199,560)
Impairments		(38,655)
Write-off of intangibles		(48,112)
Gross balance, August 31, 2019		2,250,812
Less: accumulated depreciation		(455,995)
Accumulated amortization		(58,413)
Other non-real estate assets held for sale		43
Net investments	25,731	$ 1,736,447	$ 25,731
Net Dispositions	$ (2,377,722)