Sales and revenue contract information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Trade receivables from dealers and end users	$ 6,476		$ 6,476		$ 6,310	$ 7,648
Long term trade receivables from dealers and end users	667		667		657	693
Contract liabilities	1,577		1,577		$ 1,526	$ 1,654
Revenue recognized from contract liability balance at beginning of period	121	$ 144	795	$ 843
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Unsatisfied performance obligations with an original contract duration greater than one year	$ 5,800		$ 5,800
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Expected period of performance satisfaction	12 months		12 months
Revenue, Remaining Performance Obligation, Percentage	33.00%		33.00%