General - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended		3 Months Ended
	May 31, 2021	Mar. 31, 2021	Mar. 31, 2021
Disclosure of General Information [Line Items]
Additional funds received from government by CARES Act			$ 188
Medicare Accelerated and Advance Payment Program
Disclosure of General Information [Line Items]
Medicare accelerated payments received		$ 695
Forecast
Disclosure of General Information [Line Items]
Return of funds by CARES Act to government	$ 188