Restructuring Costs (Details) $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended		19 Months Ended
	Mar. 31, 2017 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Mar. 31, 2017 USD ($)
Restructuring and Related Cost [Abstract]
Restructuring costs		$ 752	$ 161	$ 1,019
Employee Separation Charges [Roll Forward]
Liability balance at beginning of period		147	483	483
Increase in liability (separation charges)		464		297
Reduction in liability (payments)		(62)		(633)
Liability balance at end of period	$ 549	549		147	$ 483	$ 549
September 2015 announcement
Restructuring and Related Cost [Abstract]
Restructuring costs		705		281	$ 569	1,555
Estimated restructuring costs	265	265				265
Discontinue production on-highway vocational trucks
Restructuring and Related Cost [Abstract]
Restructuring costs				104
Estimated restructuring costs	6	6				6
Q3 2016 announcement
Restructuring and Related Cost [Abstract]
Restructuring costs		5		$ 369
Estimated restructuring costs	12	12				12
Gosselies closure announcement
Restructuring and Related Cost [Abstract]
Restructuring costs		671
Estimated restructuring costs	$ 750	750				$ 750
Positions eliminated	2,000
Employee separations | Gosselies closure announcement
Restructuring and Related Cost [Abstract]
Restructuring costs		439
Employee separations | Other Operating Income (Expense)
Restructuring and Related Cost [Abstract]
Restructuring costs		464	31
Contract terminations | Other Operating Income (Expense)
Restructuring and Related Cost [Abstract]
Restructuring costs		9	11
Long-lived asset impairments | Gosselies closure announcement
Restructuring and Related Cost [Abstract]
Restructuring costs		199
Long-lived asset impairments | Other Operating Income (Expense)
Restructuring and Related Cost [Abstract]
Restructuring costs		212	82
Defined benefit retirement plan curtailments and termination benefits | Other Operating Income (Expense)
Restructuring and Related Cost [Abstract]
Restructuring costs		29	0
Other | Gosselies closure announcement
Restructuring and Related Cost [Abstract]
Restructuring costs		33
Other | Other Operating Income (Expense)
Restructuring and Related Cost [Abstract]
Restructuring costs		$ 38	$ 37