Revenues - Practical expedients and other revenue disclosures (Detail) $ in Millions	Jun. 30, 2020 USD ($)
Disaggregation of Revenue [Line Items]
Revenue from remaining performance obligation	$ 496
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01
Disaggregation of Revenue [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue from remaining performance obligation	$ 216
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01
Disaggregation of Revenue [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue from remaining performance obligation	$ 110
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01
Disaggregation of Revenue [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue from remaining performance obligation	$ 46