Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			3
Total revenue and other operating income	$ 784,167	$ 757,291	$ 2,344,539	$ 2,261,346
Total segment operating income	198,123	184,901	607,250	558,078
General and administrative expense (including non-cash stock-based compensation expense)	44,929	43,076	137,325	137,021
Facility operating lease expense	51,937	53,145	154,397	149,784
Depreciation and amortization	90,064	85,932	264,219	255,314
Asset impairment	934	9,086	2,642	9,606
Loss (gain) on sale of communities, net	0	0	0	(36,296)
Income (loss) from operations	10,259	(6,338)	48,667	42,649
Total assets	5,939,123		5,939,123		$ 5,573,435
Goodwill	27,321		27,321		27,321
Independent Living
Segment Reporting Information [Line Items]
Goodwill	27,300		27,300		27,300
Operating Segments | Independent Living
Segment Reporting Information [Line Items]
Total revenue and other operating income	150,380	141,449	448,870	422,993
Total segment operating income	48,747	44,702	147,724	137,896
Total assets	1,226,716		1,226,716		1,206,021
Operating Segments | Assisted Living and Memory Care
Segment Reporting Information [Line Items]
Total revenue and other operating income	510,084	496,232	1,528,147	1,475,322
Total segment operating income	131,768	126,731	405,381	375,940
Total assets	3,651,503		3,651,503		3,315,921
Operating Segments | CCRCs
Segment Reporting Information [Line Items]
Total revenue and other operating income	83,265	82,065	250,662	251,446
Total segment operating income	14,932	10,902	46,235	36,589
Total assets	647,693		647,693		612,521
Operating Segments | Corporate and All Other
Segment Reporting Information [Line Items]
Total revenue and other operating income	40,438	37,545	116,860	111,585
Total segment operating income	2,676	$ 2,566	7,910	$ 7,653
Total assets	$ 413,211		$ 413,211		$ 438,972