Restructuring and Transformation Charges (Restructuring Charges) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	$ 20	$ 38	$ 40	$ 63
2016-17 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges		38		63
2016-17 Plan [Member] | Western Hemisphere
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges		13		17
2016-17 Plan [Member] | Eastern Hemisphere
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges		18		27
2016-17 Plan [Member] | Corporate, Non-Segment
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges		7		19
2016-17 Plan [Member] | Employee Severance
Restructuring Cost and Reserve [Line Items]
Severance costs		29		40
2016-17 Plan [Member] | Employee Severance | Western Hemisphere
Restructuring Cost and Reserve [Line Items]
Severance costs		11		15
2016-17 Plan [Member] | Employee Severance | Eastern Hemisphere
Restructuring Cost and Reserve [Line Items]
Severance costs		14		18
2016-17 Plan [Member] | Employee Severance | Corporate, Non-Segment
Restructuring Cost and Reserve [Line Items]
Severance costs		4		7
2016-17 Plan [Member] | Other Restructuring
Restructuring Cost and Reserve [Line Items]
Other restructuring costs		9	37	23
2016-17 Plan [Member] | Other Restructuring | Western Hemisphere
Restructuring Cost and Reserve [Line Items]
Other restructuring costs		2		2
2016-17 Plan [Member] | Other Restructuring | Eastern Hemisphere
Restructuring Cost and Reserve [Line Items]
Other restructuring costs		4		9
2016-17 Plan [Member] | Other Restructuring | Corporate, Non-Segment
Restructuring Cost and Reserve [Line Items]
Other restructuring costs		$ 3		$ 12
Transformation Plan [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	20		40
Transformation Plan [Member] | Western Hemisphere
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	10		15
Transformation Plan [Member] | Eastern Hemisphere
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	2		7
Transformation Plan [Member] | Corporate, Non-Segment
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	8		18
Transformation Plan [Member] | Employee Severance
Restructuring Cost and Reserve [Line Items]
Severance costs	1		3
Transformation Plan [Member] | Employee Severance | Western Hemisphere
Restructuring Cost and Reserve [Line Items]
Severance costs	1		2
Transformation Plan [Member] | Employee Severance | Eastern Hemisphere
Restructuring Cost and Reserve [Line Items]
Severance costs	0		1
Transformation Plan [Member] | Employee Severance | Corporate, Non-Segment
Restructuring Cost and Reserve [Line Items]
Severance costs	0		0
Transformation Plan [Member] | Other Restructuring
Restructuring Cost and Reserve [Line Items]
Other restructuring costs	19
Transformation Plan [Member] | Other Restructuring | Western Hemisphere
Restructuring Cost and Reserve [Line Items]
Other restructuring costs	9		13
Transformation Plan [Member] | Other Restructuring | Eastern Hemisphere
Restructuring Cost and Reserve [Line Items]
Other restructuring costs	2		6
Transformation Plan [Member] | Other Restructuring | Corporate, Non-Segment
Restructuring Cost and Reserve [Line Items]
Other restructuring costs	$ 8		$ 18