Commitments and Contingencies (Detail)	Jun. 30, 2021 USD ($)
Indemnification Agreement
Other Commitments [Line Items]
Liabilities under guarantor agreements	$ 0
Indemnification Agreement Two
Other Commitments [Line Items]
Liabilities under guarantor agreements	0
Indemnification Agreement Three
Other Commitments [Line Items]
Liabilities under guarantor agreements	0
Service Level Credits Agreement
Other Commitments [Line Items]
Liabilities under guarantor agreements	0
Capital expenditures
Other Commitments [Line Items]
Purchase commitments	1,500,000,000
Miscellaneous purchase commitments
Other Commitments [Line Items]
Purchase commitments	$ 1,300,000,000