Schedule III - Real Estate and Accumulated Depreciation - Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Initial cost of encumbrances	$ 2,222,445
Initial cost of land and land improvements	4,157,359
Initial cost of building and improvements	34,084,618
Cost Capitalized Subsequent to Acquisition	8,207,202
Carrying amount of land and land improvements	4,697,824
Carrying amount of building and improvements	41,640,347
Accumulated depreciation	9,274,814	$ 8,075,733	$ 6,910,114	$ 6,104,297
Construction in progress
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Initial cost of encumbrances	7,228
Initial cost of land and land improvements	0
Initial cost of building and improvements	1,304,441
Cost Capitalized Subsequent to Acquisition	0
Carrying amount of land and land improvements	0
Carrying amount of building and improvements	1,304,441
Accumulated depreciation	0
Seniors Housing Operating
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Initial cost of encumbrances	1,760,778
Initial cost of land and land improvements	2,296,482
Initial cost of building and improvements	20,037,488
Cost Capitalized Subsequent to Acquisition	4,923,531
Carrying amount of land and land improvements	2,620,060
Carrying amount of building and improvements	24,637,441
Accumulated depreciation	5,754,186
Seniors Housing Operating | Operating Segments
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Initial cost of encumbrances	1,760,778
Initial cost of land and land improvements	2,296,482
Initial cost of building and improvements	20,037,488
Cost Capitalized Subsequent to Acquisition	4,923,531
Carrying amount of land and land improvements	2,620,060
Carrying amount of building and improvements	24,637,441
Accumulated depreciation	5,754,186
Triple-net
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Initial cost of encumbrances	38,261
Initial cost of land and land improvements	970,310
Initial cost of building and improvements	7,578,624
Cost Capitalized Subsequent to Acquisition	645,258
Carrying amount of land and land improvements	1,016,599
Carrying amount of building and improvements	8,177,593
Accumulated depreciation	1,694,904
Triple-net | Operating Segments
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Initial cost of encumbrances	38,261
Initial cost of land and land improvements	970,310
Initial cost of building and improvements	7,578,624
Cost Capitalized Subsequent to Acquisition	645,258
Carrying amount of land and land improvements	1,016,599
Carrying amount of building and improvements	8,177,593
Accumulated depreciation	1,694,904
Outpatient Medical
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Initial cost of encumbrances	229,137
Initial cost of land and land improvements	848,834
Initial cost of building and improvements	4,756,618
Cost Capitalized Subsequent to Acquisition	2,603,702
Carrying amount of land and land improvements	1,061,165
Carrying amount of building and improvements	7,147,989
Accumulated depreciation	1,825,724
Outpatient Medical | Operating Segments
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Initial cost of encumbrances	229,137
Initial cost of land and land improvements	848,834
Initial cost of building and improvements	4,756,618
Cost Capitalized Subsequent to Acquisition	2,603,702
Carrying amount of land and land improvements	1,061,165
Carrying amount of building and improvements	7,147,989
Accumulated depreciation	1,825,724
Total continuing operating properties
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Initial cost of encumbrances	2,035,404
Initial cost of land and land improvements	4,115,626
Initial cost of building and improvements	33,677,171
Cost Capitalized Subsequent to Acquisition	8,172,491
Carrying amount of land and land improvements	4,697,824
Carrying amount of building and improvements	41,267,464
Accumulated depreciation	9,274,814
Assets held for sale
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]
Initial cost of encumbrances	187,041
Initial cost of land and land improvements	41,733
Initial cost of building and improvements	407,447
Cost Capitalized Subsequent to Acquisition	34,711
Carrying amount of land and land improvements	0
Carrying amount of building and improvements	372,883
Accumulated depreciation	$ 0