Joint Ventures - Unconsolidated JV - Watersound Fountains Independent Living JV (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 30, 2021 USD ($) item	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Investments
Net income (loss)		$ 14,777	$ 7,782	$ 41,759	$ 25,666
Summarized financial information
Investment in real estate		647,874		647,874			$ 551,653
Cash and cash equivalents		27,260	102,351	27,260	102,351		106,794
Other assets		69,897		69,897			65,866
Total assets		1,136,550		1,136,550			1,037,324
Other liabilities		91,758		91,758			72,035
Equity		598,618	$ 552,420	598,618	$ 552,420	$ 588,515	568,170	$ 542,650	$ 529,670
Total liabilities and equity		1,136,550		1,136,550			$ 1,037,324
Watersound Fountains Independent Living JV
Investments
Value of land contributed	$ 3,200
Cash contributed				4,300
Cash contributed by JV partner		6,400		6,400
Net income (loss)		$ 0		$ 0
Ownership percentage		53.80%		53.80%
Watersound Fountains Independent Living JV
Investments
Number of JV partners | item	3
Summarized financial information
Investment in real estate		$ 10,303		$ 10,303
Cash and cash equivalents		4,594		4,594
Other assets		199		199
Total assets		15,096		15,096
Other liabilities		1,140		1,140
Equity		13,956		13,956
Total liabilities and equity		$ 15,096		$ 15,096
Watersound Fountains Independent Living JV | Senior living community
Investments
Number of units to be developed | item	148