Real Property Acquisitions and Development - Construction Activity (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Total development projects	$ 170,308	$ 28,117
Expansion projects	35,637	0
Total construction in progress conversions	205,945	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	33,627	0
Outpatient Medical
Segment Reporting Information [Line Items]
Total development projects	$ 43,493	$ 0