Segment Reporting (Narrative) (Details)	12 Months Ended
	Dec. 31, 2019 property segment	Dec. 31, 2018 segment	Dec. 31, 2017 segment	Dec. 31, 2019 encumbered_property
Segment Reporting [Abstract]
Number of reportable segments | segment	3	3	3
Segment Reporting Information [Line Items]
Number of real estate properties	193			102
NuVista
Segment Reporting Information [Line Items]
Number of real estate properties	2
NuVista | Transition Property
Segment Reporting Information [Line Items]
Number of real estate properties	1