Restructuring and other impairment charges - expected costs to be incurred (Details) $ in Millions	Dec. 31, 2018 USD ($)
2018 Footprint realignment plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	$ 102
2018 Footprint realignment plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	133
2014 Manufacturing footprint realignment plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	47
2014 Manufacturing footprint realignment plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	52
Termination benefits | 2018 Footprint realignment plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	60
Termination benefits | 2018 Footprint realignment plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	70
Termination benefits | 2014 Manufacturing footprint realignment plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	12
Termination benefits | 2014 Manufacturing footprint realignment plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	13
Other Costs | 2018 Footprint realignment plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	2
Other Costs | 2018 Footprint realignment plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	4
Other Costs | 2014 Manufacturing footprint realignment plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	1
Other Costs | 2014 Manufacturing footprint realignment plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	2
Restructuring charges | 2018 Footprint realignment plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	62
Restructuring charges | 2018 Footprint realignment plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	74
Restructuring charges | 2014 Manufacturing footprint realignment plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	13
Restructuring charges | 2014 Manufacturing footprint realignment plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	15
Accelerated Depreciation And Other Costs | 2018 Footprint realignment plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	40
Accelerated Depreciation And Other Costs | 2018 Footprint realignment plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	59
Accelerated Depreciation And Other Costs | 2014 Manufacturing footprint realignment plan | Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	34
Accelerated Depreciation And Other Costs | 2014 Manufacturing footprint realignment plan | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	$ 37