Revenue Recognition (Details) $ in Billions	12 Months Ended
	Dec. 31, 2018 USD ($)
Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
General payment terms	30 days
Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
General payment terms	60 days
Up front customer loyalty programs and volume commitment programs
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Estimation of future revenues	$ 1.3