Real Property Acquisitions and Development - Construction Activity (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Total development projects	$ 195,882	$ 28,117
Expansion projects	48,600	0
Total construction in progress conversions	244,482	28,117
Seniors Housing Operating
Segment Reporting Information [Line Items]
Total development projects	93,188	28,117
Triple-net
Segment Reporting Information [Line Items]
Total development projects	59,201	0
Outpatient Medical
Segment Reporting Information [Line Items]
Total development projects	$ 43,493	$ 0