Real Property Acquisitions and Development - Construction Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Development projects:
Total development projects	$ 265,555	$ 211,830	$ 49,123
Expansion projects	5,292	48,600	0
Total construction in progress conversions	270,847	260,430	49,123
Seniors Housing Operating
Development projects:
Total development projects	117,386	93,188	28,117
Triple-net
Development projects:
Total development projects	22,990	75,149	0
Outpatient Medical
Development projects:
Total development projects	$ 125,179	$ 43,493	$ 21,006