Summary of Significant Accounting Policies - Leasing Costs and Revenue Recognition (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) community	Dec. 31, 2021 USD ($) community	Dec. 31, 2020 USD ($)
DEFERRED LEASING COSTS
Unamortized gross balance of deferred leasing costs	$ 55,043,000	$ 64,255,000
Accumulated amortization	$ 15,482,000	17,074,000
Weighted average amortization period for deferred leasing cost	8 years 1 month 6 days
Expected amortization expense for the five years
Expected amortization expense, 2023	$ 6,652,000
Expected amortization expense, 2024	5,840,000
Expected amortization expense, 2025	5,379,000
Expected amortization expense, 2026	4,805,000
Expected amortization expense, 2027	3,781,000
Expected amortization expense, thereafter	13,104,000
Percentage rents earned	2,978,000	1,993,000	$ 2,144,000
Proceeds from the relief fund amount	605,000	20,800,000	19,961,000
Interest and other income	15,929,000	20,635,000	18,221,000
Provider relief fund other liabilities	$ 0	$ 3,722,000	2,476,000
Senior Living Communities
Expected amortization expense for the five years
Number of communities managed | community	111	107
SHOP
Expected amortization expense for the five years
Interest and other income	$ 4,327,000	$ 19,554,000
SHOP | Operating Segments
Expected amortization expense for the five years
Interest and other income			$ 17,485,000
Third Party Managers | Senior Living Communities
Expected amortization expense for the five years
Number of communities managed | community	237