Sales and revenue contract information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Trade receivables from dealers and end users	$ 6,889		$ 6,310	$ 7,648
Long term trade receivables from dealers and end users	612		657	693
Contract liabilities	1,584		$ 1,526	$ 1,654
Revenue recognized from contract liability balance at beginning of period	433	$ 368
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Unsatisfied performance obligations with an original contract duration greater than one year	$ 6,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Expected period of performance satisfaction	12 months
Revenue, Remaining Performance Obligation, Percentage	33.00%