Segment Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) segment	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			3
Revenue	$ 750,792	$ 689,516	$ 1,504,055	$ 1,367,336
Segment operating income	185,675	138,464	373,177	266,379
General and administrative expense (including non-cash stock-based compensation expense)	45,326	41,752	93,945	86,878
Facility lease expense	50,512	41,538	96,639	83,102
Depreciation and amortization	84,448	86,623	169,382	172,307
Asset impairment	520	2,599	520	11,674
Loss (gain) on sale of communities, net	(36,296)	0	(36,296)	0
Income (loss) from operations	41,165	(34,048)	48,987	(87,582)
Total assets	5,904,735		5,904,735		$ 5,937,062
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	140,888	126,737	281,544	251,143
Segment operating income	46,361	38,709	93,194	76,393
Total assets	1,241,836		1,241,836		1,267,825
Operating Segments | Assisted Living and Memory Care
Segment Reporting Information [Line Items]
Revenue	490,286	440,866	979,090	873,354
Segment operating income	124,616	87,588	249,209	164,451
Total assets	3,376,440		3,376,440		3,329,516
Operating Segments | CCRCs
Segment Reporting Information [Line Items]
Revenue	83,109	81,196	169,381	161,652
Segment operating income	12,188	8,838	25,687	18,877
Total assets	636,509		636,509		664,502
Operating Segments | Corporate and All Other
Segment Reporting Information [Line Items]
Revenue	36,509	40,717	74,040	81,187
Segment operating income	2,510	$ 3,329	5,087	$ 6,658
Total assets	$ 649,950		$ 649,950		$ 675,219