Segment Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) segment	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			3
Revenue	$ 777,541	$ 750,792	$ 1,560,372	$ 1,504,055
Segment operating income	204,818	185,675	409,127	373,177
General and administrative expense (including non-cash stock-based compensation expense)	46,664	45,326	92,396	93,945
Facility lease expense	50,964	50,512	102,460	96,639
Depreciation and amortization	88,028	84,448	174,155	169,382
Asset impairment	0	520	1,708	520
Loss (gain) on sale of communities, net	0	(36,296)	0	(36,296)
Income (loss) from operations	19,162	41,165	38,408	48,987
Total assets	5,450,886		5,450,886		$ 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]
Revenue	149,542	140,888	298,490	281,544
Segment operating income	50,334	46,361	98,977	93,194
Total assets	1,174,509		1,174,509		1,206,021
Operating Segments | Assisted Living and Memory Care
Segment Reporting Information [Line Items]
Revenue	507,191	490,286	1,018,063	979,090
Segment operating income	136,155	124,616	273,613	249,209
Total assets	3,227,652		3,227,652		3,315,921
Operating Segments | CCRCs
Segment Reporting Information [Line Items]
Revenue	82,976	83,109	167,397	169,381
Segment operating income	15,713	12,188	31,303	25,687
Total assets	598,719		598,719		612,521
Operating Segments | Corporate and All Other
Segment Reporting Information [Line Items]
Revenue	37,832	36,509	76,422	74,040
Segment operating income	2,616	$ 2,510	5,234	$ 5,087
Total assets	$ 450,006		$ 450,006		$ 438,972