Revenue from Contracts With Customers - Performance obligations (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Practical Expedient, Initial Application and Transition, Nondisclosure of Transaction Price Allocation to Remaining Performance Obligation [true false]	true
Sales expected to be recognized on multi-year contracts in place as of the end of the period	$ 1,994
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Period in which remaining performance obligations expect to be satisfied and revenue recognized	12 months
Sales expected to be recognized on multi-year contracts in place as of the end of the period	$ 1,180
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Period in which remaining performance obligations expect to be satisfied and revenue recognized
Sales expected to be recognized on multi-year contracts in place as of the end of the period	$ 814