Fair Value Measurements - Additional Information (Details) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	Jul. 26, 2020 USD ($) $ / shares shares	Sep. 30, 2020 USD ($) community lease shares	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) community lease shares	Sep. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) community	Mar. 31, 2020 USD ($) community	Dec. 31, 2019 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities		$ 136,136		$ 136,136				$ 68,567
Debt		$ 3,930,165		$ 3,930,165				3,555,123
Number of shares authorized to be purchased | shares		16,300,000		16,300,000
Number of communities leased | lease		236		236
Operating lease, right of use assets impairment charge		$ 3,300		$ 75,600
Ventas, Inc | The Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of shares authorized to be purchased | shares	16,300,000
Share price (in usd per share) | $ / shares	$ 3.00
Value of warrants issued	$ 22,900
Expected volatility rate	65.00%
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities		136,100		136,100
Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Operating lease, right of use assets impairment charge		3,300	$ 0	75,600	$ 0
Property, plant and equipment and leasehold intangibles impairment charge		$ 4,900	$ 800	$ 19,600	$ 2,000
Condensed Consolidated Balance Sheet
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of communities leased | community		2		2		9	35
Estimated fair value		$ 3,000		$ 3,000		$ 10,300	$ 106,700
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate		11.20%		11.20%
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate		12.30%		12.30%
Long-term debt and lines of credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt		$ 3,900,000		$ 3,900,000				$ 3,600,000