Trade Accounts Receivable, Unbilled Services and Unearned Income - Schedule of Net Contract Assets (Liabilities) (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)
Unbilled services
Unbilled services, beginning balance	$ 1,263
Change	46
Unbilled services, ending balance	1,309
Unearned income
Unearned income, beginning balance	(1,252)
Change	(573)
Unearned income, ending balance	(1,825)
Net balance, beginning balance	11
Decrease of net balance of unbilled services and unearned income	(527)
Net balance, ending balance	$ (516)