Segment Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) segment	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	3
Revenue	$ 753,263	$ 677,820
Segment operating income	187,502	127,915
General and administrative expense (including non-cash stock-based compensation expense)	48,619	45,126
Facility lease expense	46,127	41,564
Depreciation and amortization	84,934	85,684
Asset impairment	0	9,075
Income (loss) from operations	7,822	(53,534)
Total assets	5,885,859		$ 5,937,062
Goodwill	27,321		27,321
Other operating income
Segment Reporting Information [Line Items]
Revenue	2,328	376
Independent Living
Segment Reporting Information [Line Items]
Goodwill	27,300		27,300
Operating Segments | Independent Living
Segment Reporting Information [Line Items]
Revenue	140,656	124,406
Segment operating income	46,833	37,684
Total assets	1,253,570		1,267,825
Operating Segments | Assisted Living and Memory Care
Segment Reporting Information [Line Items]
Revenue	488,804	432,488
Segment operating income	124,593	76,863
Total assets	3,288,702		3,329,516
Operating Segments | CCRCs
Segment Reporting Information [Line Items]
Revenue	86,272	80,456
Segment operating income	13,499	10,039
Total assets	666,102		664,502
Operating Segments | Corporate and All Other
Segment Reporting Information [Line Items]
Revenue	37,531	40,470
Segment operating income	2,577	$ 3,329
Total assets	$ 677,485		$ 675,219