Fair Value of Financial Instruments - Summary of Fair Value Information of Financial Instruments (Parenthetical) (Detail) - Fair Value, Recurring $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) Health_Center	Dec. 31, 2019 USD ($) Health_Center
Colombia [Member]
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Number of facilities acquired | Health_Center	3
Acquisition Loans [Member]
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Fair value | $	$ 205	$ 205
Book value | $	$ 205	$ 205
Acquisition Loans [Member] | Colombia [Member]
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Number of facilities acquired | Health_Center	3	3