Accounting Policies and Related Matters - Spot Occupancy (Details) - properties	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Mar. 12, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Spot occupancy properties	546
Seniors Housing Operating
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Percent of communities open	94.00%
Seniors Housing Operating | COVID-19
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Spot occupancy	77.70%	76.90%	74.80%	72.90%	72.60%	74.90%
Sequential occupancy change	0.70%	2.10%	1.90%	(1.90%)