Debt - Mortgage Debt (Details) $ in Thousands	1 Months Ended
	Jul. 31, 2019 USD ($) property	Jun. 30, 2019 property	May 31, 2019 USD ($) property	Apr. 30, 2019 property	Dec. 31, 2019 USD ($) facility
Debt Instrument [Line Items]
Long-term debt, gross					$ 6,307,244
Mortgage debt
Debt Instrument [Line Items]
Long-term debt, gross					$ 264,244
Number of healthcare facilities used to secure debt (in facilities) | facility					17
Debt instrument, collateral, healthcare facilities carrying value					$ 511,000
Weighted-average interest rate (as a percent)					4.09%
Senior housing
Debt Instrument [Line Items]
Number of properties acquired | property		1
Senior housing | Senior housing
Debt Instrument [Line Items]
Number of properties acquired | property	5		3	9
Mortgage debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 112,000		$ 50,000
Weighted-average interest rate (as a percent)	4.89%		4.83%