DESCRIPTION OF BUSINESS - Schedule of reportable business segments and non-segment assets (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) property	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Real estate properties
NOI | $	$ 1,925,167	$ 1,842,640	$ 1,724,701
Percentage of Total NOI	100.00%
Number of Properties | property	1,355
Outpatient Medical And Research Portfolio
Real estate properties
Percentage of Total NOI	30.00%
Number of Properties | property	437
Triple-net leased properties
Real estate properties
Percentage of Total NOI	31.00%
Number of Properties | property	331
Non-Segment
Real estate properties
Percentage of Total NOI	2.00%
Number of Properties | property	0
Operating Segments | Seniors Housing Communities Managed by Independent Operators
Real estate properties
Percentage of Total NOI	37.00%
Number of Properties | property	587
Operating Segments | SHOP
Real estate properties
NOI | $	$ 711,407	647,466	458,273
Operating Segments | Outpatient Medical And Research Portfolio
Real estate properties
NOI | $	576,932	546,604	543,882
Operating Segments | Triple-net leased properties
Real estate properties
NOI | $	604,651	582,853	638,488
Non-Segment
Real estate properties
NOI | $	$ 32,177	$ 65,717	$ 84,058