Acquisitions, Dispositions and Other Significant Transactions - Healthpeak CCRC Venture and Master Lease Transactions (Details) $ in Thousands			1 Months Ended		3 Months Ended	12 Months Ended
	Jan. 31, 2020 USD ($) community extensionOption	Oct. 01, 2019 USD ($) entryFee community	Dec. 31, 2020 community	Mar. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) community	Dec. 31, 2019 USD ($)
Business Acquisition [Line Items]
Number of additional entry fee | entryFee		1
Gain (loss) on sale of assets, net						$ 288,835	$ 374,532	$ 7,245
Gain on facility lease termination						2,003	2,303	(3,388)
Gain (loss) on debt modification and extinguishment, net						$ (1,932)	10,896	$ (5,247)
CCRC Venture | CCRCs
Business Acquisition [Line Items]
Number of entry fee | entryFee		14
Purchase price		$ 289,200
Payments to acquire interest in joint venture		$ 1,060,000
Number of entry fee sales | entryFee		2
Number of owned communities transferred | community		2
CCRC Venture | CCRCs | CCRC Venture
Business Acquisition [Line Items]
Percentage of voting interests acquired		51.00%
HCP, Inc. | CCRCs
Business Acquisition [Line Items]
Purchase price							289,200
Post closing working capital adjustment obligation					$ 5,900
Gain (loss) on sale of assets, net							369,800
Payments for management agreement termination fee		$ 100,000
Master Lease Transactions
Business Acquisition [Line Items]
Number of continuing communities | community	24
Base rent	$ 41,700
Annual escalator rate	2.40%
Gain (loss) on debt modification and extinguishment, net							19,700
Financing lease obligations, carrying value							$ 105,100
Number of communities previously subject to sale leaseback transactions | community							8
Master Lease Transactions | HCP, Inc.
Business Acquisition [Line Items]
Payments to acquire interest in joint venture	$ 405,500
Number of communities leased | community	25
Number of communities, acquired, currently leased | community	18
Acquisition related costs	$ 1,700
Number of lease communities transferred to successor operator | community			1
Gain on facility lease termination							$ 2,300
Number of continuing communities | community	24
Number of extensions | extensionOption	2
Term of number of extensions	10 years
Capital expenditures	$ 35,000
Initial lease rate	7.00%
Non-Recourse First Mortgages | Master Lease Transactions
Business Acquisition [Line Items]
Proceeds from issuance of debt	$ 192,600			$ 30,000