Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Oct. 01, 2021	Jan. 01, 2019	Dec. 31, 2018
Revenue Recognition
Term of residency agreements - minimum	30 days
Term of residency agreements - maximum	1 year
Stock-Based Compensation
Award vesting period	3 years
Award requisite service period	4 years
Weighted average volatility rate		42.50%	45.20%
Risk free interest rate		1.40%	2.40%
Accounting Standards Update and Change in Accounting Principle
Operating lease obligations	$ 830,518,000
Operating lease right-of-use assets	630,423,000	$ 788,138,000
Cumulative effect of change in accounting principle	699,623,000	802,729,000	$ 698,725,000			$ 1,018,413,000
Deferred tax position	0	9,557,000
Deferred tax asset	279,000	0
Change in valuation allowance	367,963,000	380,990,000
Convertible Senior Notes Due 2026 | Convertible notes payable
Accounting Standards Update and Change in Accounting Principle
Debt face amount				$ 230,000,000
Interest rate				2.00%
Accumulated Deficit
Accounting Standards Update and Change in Accounting Principle
Cumulative effect of change in accounting principle	$ (3,410,474,000)	(3,311,184,000)	(3,393,088,000)			(3,069,272,000)
Cumulative Effect, Period of Adoption, Adjustment | Accumulated Deficit
Accounting Standards Update and Change in Accounting Principle
Cumulative effect of change in accounting principle		$ 0	$ (115,000)			(55,885,000)
ASU 2016-02
Accounting Standards Update and Change in Accounting Principle
Operating lease obligations					$ 1,618,000,000	231,400,000
Operating lease right-of-use assets					1,329,000,000
Cumulative effect of change in accounting principle					(56,000,000)
Deferred tax position						300,000
Deferred tax asset						14,100,000
Change in valuation allowance						$ 13,800,000
ASU 2016-02 | Cumulative Effect, Period of Adoption, Adjustment | Accumulated Deficit
Accounting Standards Update and Change in Accounting Principle
Cumulative effect of change in accounting principle					$ 58,100,000
Minimum
Stock-Based Compensation
Award vesting period	3 years
Award vesting rights percentage	0.00%
Fair value vesting rights, percentage	0.00%
Maximum
Stock-Based Compensation
Award vesting period	4 years
Award vesting rights percentage	125.00%
Fair value vesting rights, percentage	150.00%