Real Property Acquisitions and Development - Narrative (Details)		1 Months Ended		3 Months Ended						9 Months Ended
	Sep. 30, 2024 USD ($) property	Jul. 31, 2024 USD ($) property	Feb. 29, 2024 USD ($) property	Sep. 30, 2024 USD ($) property	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Sep. 30, 2023 USD ($) property joint_venture	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2024 USD ($) property	Sep. 30, 2023 USD ($) property joint_venture	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	[1]
Asset Acquisition [Line Items]
Net change in noncontrolling interests				$ 11,810,000	$ 353,525,000	$ 13,091,000	$ (53,995,000)	$ 153,120,000	$ (21,344,000)
Secured debt	$ 2,468,527,000			2,468,527,000						$ 2,468,527,000			$ 2,183,327,000
Gain (loss) on real estate dispositions and acquisitions of controlling interests, net				272,266,000			71,102,000			443,416,000	$ 69,681,000
Forecast
Asset Acquisition [Line Items]
Contingent consideration												$ 150,000,000
Seniors Housing Operating Properties, Affinity Brand
Asset Acquisition [Line Items]
Contingent consideration	$ 75,074,000			$ 75,074,000						$ 75,074,000
Number of assets acquired | property	20		25	20						20
Expected consideration			$ 969,000,000
Consideration transferred				$ 690,510,000
Equity issued in acquisition				203,328
Secured debt in acquisition				$ 364,130,000
Seniors Housing Real Estate Portfolio
Asset Acquisition [Line Items]
Number of assets acquired | property		136
Expected consideration		$ 1,000,000,000.0
Equity Method Joint Venture
Asset Acquisition [Line Items]
Number of properties | property	39			39						39
Percentage ownership	25.00%			25.00%						25.00%
Payments for investments	$ 205,029,000
Secured debt	$ 532,575,000			$ 532,575,000						$ 532,575,000
Gain (loss) on real estate dispositions and acquisitions of controlling interests, net				$ 179,770,000
Joint Ventures Canadian Pension Plan Investment Board
Asset Acquisition [Line Items]
Acquisitions of noncontrolling interests							$ 69,606,000
Ownership interest (in percent)							45.00%				45.00%
Number of joint ventures | joint_venture							2				2
Net change in noncontrolling interests							$ 118,256,000
Joint Ventures Canadian Pension Plan Investment Board | Office Building
Asset Acquisition [Line Items]
Number of properties | property							10				10

[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.