Summary of Significant Accounting Policies - Useful lives of real estate assets and liabilities (Details)	12 Months Ended
	Dec. 31, 2019
Lease intangibles (including ground lease intangibles) | Minimum [Member]
Property, Plant and Equipment [Line Items]
Asset estimated useful life	2 years 1 month 6 days
Intangible asset useful life	2 years 1 month 6 days
Lease intangibles (including ground lease intangibles) | Maximum [Member]
Property, Plant and Equipment [Line Items]
Asset estimated useful life	99 years
Intangible asset useful life	99 years
Land improvements | Minimum [Member]
Property, Plant and Equipment [Line Items]
Asset estimated useful life	3 years
Land improvements | Maximum [Member]
Property, Plant and Equipment [Line Items]
Asset estimated useful life	39 years
Building and improvements | Minimum [Member]
Property, Plant and Equipment [Line Items]
Asset estimated useful life	3 years 3 months 18 days
Building and improvements | Maximum [Member]
Property, Plant and Equipment [Line Items]
Asset estimated useful life	39 years
Personal property | Minimum [Member]
Property, Plant and Equipment [Line Items]
Asset estimated useful life	2 years 9 months 18 days
Personal property | Maximum [Member]
Property, Plant and Equipment [Line Items]
Asset estimated useful life	20 years