Dispositions, Real Property Held for Sale and Impairment - Strategic Dissolution of Revera Joint Ventures (Details) $ in Thousands			1 Months Ended			3 Months Ended		9 Months Ended		12 Months Ended
	Apr. 01, 2024 property	May 01, 2023 USD ($)	Apr. 30, 2024 USD ($) property	Jun. 30, 2023 USD ($) property joint_venture	Mar. 31, 2021 USD ($) property	Sep. 30, 2023 USD ($) property project	Jun. 30, 2023 USD ($) property joint_venture	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($) property		Mar. 31, 2023 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Non-cash consideration								$ 434,326	$ 361,830
Net real estate investments								41,868,096		$ 38,775,913	[1]
Right of use assets, net								358,160		350,969	[1]
Lease liabilities								$ 392,360		$ 383,230	[1]
Gain from leasehold interest		$ 65,485
U K Portfolio Revera Joint Venture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of joint ventures | joint_venture				2			2
U K Portfolio Revera Joint Venture1
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage ownership				75.00%			75.00%
Proceeds from sale of interest			$ 60,614	$ 107,341
U K Portfolio Revera Joint Venture2
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage ownership				90.00%			90.00%
U S Portfolio Revera Joint Venture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage ownership						34.00%			34.00%
Equity method investments						$ 47,734			$ 47,734
U S Portfolio Revera Joint Venture | Revera
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage ownership						66.00%			66.00%
Canadian Portfolio, Joint Venture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage ownership						75.00%			75.00%
Joint Venture with Aurora Health Network, Peace Capital
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Equity method investments		11,571
Cash from joint venture		$ 104,240
Revera Joint Venture, Disposal Transaction
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Property sold | property			14	4		13	31
Gross sale price			$ 430,898	$ 222,521			$ 222,521
Non-cash consideration			434,326	241,728
Other consideration			219,940	198,837			198,837
Noncontrolling interest			53,174	42,891			42,891
Transaction related expenses			3,428	9,049
Real estate property			293,257	224,208		$ 119,258	224,208		$ 119,258
Gain (loss) on real estate dispositions			137,641	(1,687)		62,075
Payment for transaction related expenses disposal group			17,258	5,776
Noncontrolling Interest, decrease from deconsolidation			246,564	180,497		$ 56,905
Liabilities				22,270			$ 22,270
Realized adjustment on disposal			42,619	$ 1,846
Number of projects | project						1
Relieved amount			$ 164,640
Revera Joint Venture, Disposal Transaction | Avery Healthcare
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties transitioned | property				29
Revera Joint Venture Disposal Transaction U S Properties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Property sold | property						12
Revera Joint Venture Disposal Transaction Now Wholly Owned Properties | Oakmont Management Group
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties transitioned | property						2
Revera Joint Venture, Existing Wholly-Owned Properties | Oakmont Management Group
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties transitioned | property						26
Genesis HealthCare Operating Relationship
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Property sold | property					7
Gross sale price					$ 182,618
Right of use assets, net												$ 115,359
Lease liabilities												$ 66,530
Revera Joint Venture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Property acquired | property	71		71	29		10	110
Payment for property acquired			$ 51,986	$ 10,158
Net real estate investments						$ 479,525			479,525
Payments to acquire real estate and real estate joint ventures						31,456
Consideration transferred						448,069
Asset acquisition debt assumed						$ 270,486			$ 270,486
Revera Joint Venture | Cogir Senior Living
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Property acquired | property										53
Revera Joint Venture | Levante Living
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Property acquired | property										12
Revera Joint Venture | Optima Living
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Property acquired | property										6

[1] The consolidated balance sheet at December 31, 2023 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements.