Real Property Acquisitions and Development - Construction Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Total construction in progress conversions	$ 112,557	$ 0
Seniors Housing Operating
Segment Reporting Information [Line Items]
Total development projects	93,188	0
Outpatient Medical
Segment Reporting Information [Line Items]
Total development projects	$ 19,369	$ 0