Restructuring and Transformation Charges (Restructuring Liability) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Restructuring Reserve [Roll Forward]
Other	$ 12
Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	27
Other Restructuring | Eastern Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	9
Other Restructuring | Western Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	9
Other Restructuring | Corporate, Non-Segment
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	9
Severance and Other Restructuring Liabilities [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	59
Restructuring Charges	16
Cash Payments	(34)
Other	(14)
Accrued balance at end of period	27
Transformation Plan [Member] | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	18
Restructuring Charges	2
Cash Payments	(10)
Other	0
Accrued balance at end of period	10
Transformation Plan [Member] | Employee Severance | Eastern Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	6
Transformation Plan [Member] | Employee Severance | Western Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	4
Transformation Plan [Member] | Employee Severance | Corporate, Non-Segment
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Transformation Plan [Member] | Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	16
Restructuring Charges	14
Cash Payments	(22)
Other	(1)
Accrued balance at end of period	7
Transformation Plan [Member] | Other Restructuring | Eastern Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Transformation Plan [Member] | Other Restructuring | Western Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
Transformation Plan [Member] | Other Restructuring | Corporate, Non-Segment
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	6
2016-17 and Prior Plan [Member] | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	6
Restructuring Charges	0
Cash Payments	(1)
Other	1
Accrued balance at end of period	6
2016-17 and Prior Plan [Member] | Employee Severance | Eastern Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
2016-17 and Prior Plan [Member] | Employee Severance | Western Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	2
2016-17 and Prior Plan [Member] | Employee Severance | Corporate, Non-Segment
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	3
2016-17 and Prior Plan [Member] | Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	19
Restructuring Charges	0
Cash Payments	(1)
Other	(14)
Accrued balance at end of period	4
2016-17 and Prior Plan [Member] | Other Restructuring | Eastern Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	2
2016-17 and Prior Plan [Member] | Other Restructuring | Western Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	2
2016-17 and Prior Plan [Member] | Other Restructuring | Corporate, Non-Segment
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	$ 0