Restructuring and Transformation Charges (Restructuring Liability) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019 USD ($)
Restructuring Reserve [Roll Forward]
Other	$ 12
Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	22
Other Restructuring | Eastern Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	5
Other Restructuring | Western Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	8
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	32
Cash Payments	(52)
Other	(17)
Accrued balance at end of period	22
Transformation Plan [Member] | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	18
Restructuring Charges	3
Cash Payments	(14)
Other	(2)
Accrued balance at end of period	5
Transformation Plan [Member] | Employee Severance | Eastern Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	2
Transformation Plan [Member] | Employee Severance | Western Hemisphere
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	3
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	29
Cash Payments	(34)
Other	(3)
Accrued balance at end of period	8
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	2
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	(2)
Other	1
Accrued balance at end of period	5
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	1
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	(2)
Other	(13)
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