Restructuring Charges (Restructuring Liability) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring and Transformation Charges	$ 126	$ 183	$ 280
Severance and Other Restructuring Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	120	171	240
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	61	86	51
Cash Payments	(109)	(167)	(198)
Other	13	29	7
Accrued balance at end of period	59	61	$ 86
Severance and Other Restructuring Liabilities [Member] | Western Hemisphere [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	16
Severance and Other Restructuring Liabilities [Member] | Eastern Hemisphere [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	24
Severance and Other Restructuring Liabilities [Member] | Corporate, Non-Segment [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	19
Transformation Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Transformation Charges	126
Transformation Plan [Member] | Western Hemisphere [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Transformation Charges	27
Transformation Plan [Member] | Eastern Hemisphere [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Transformation Charges	45
Transformation Plan [Member] | Corporate, Non-Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Transformation Charges	54
Transformation Plan [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	61
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	0
Cash Payments	(35)
Other	8
Accrued balance at end of period	18	0
Transformation Plan [Member] | Employee Severance [Member] | Western Hemisphere [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	6
Transformation Plan [Member] | Employee Severance [Member] | Eastern Hemisphere [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	10
Transformation Plan [Member] | Employee Severance [Member] | Corporate, Non-Segment [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	2
Transformation Plan [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	59
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	0
Cash Payments	(43)
Other	0
Accrued balance at end of period	16	0
Transformation Plan [Member] | Other Restructuring [Member] | Western Hemisphere [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Transformation Plan [Member] | Other Restructuring [Member] | Eastern Hemisphere [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Transformation Plan [Member] | Other Restructuring [Member] | Corporate, Non-Segment [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	16
2016 - 2017 and 2016 Plans [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	21
Cash Payments	(15)
Other	0
Accrued balance at end of period	6	21
2016 - 2017 and 2016 Plans [Member] | Employee Severance [Member] | Western Hemisphere [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	3
2016 - 2017 and 2016 Plans [Member] | Employee Severance [Member] | Eastern Hemisphere [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	2
2016 - 2017 and 2016 Plans [Member] | Employee Severance [Member] | Corporate, Non-Segment [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
2016 - 2017 and 2016 Plans [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	40
Cash Payments	(16)
Other	5
Accrued balance at end of period	19	$ 40
2016 - 2017 and 2016 Plans [Member] | Other Restructuring [Member] | Western Hemisphere [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	7
2016 - 2017 and 2016 Plans [Member] | Other Restructuring [Member] | Eastern Hemisphere [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	12
2016 - 2017 and 2016 Plans [Member] | Other Restructuring [Member] | Corporate, Non-Segment [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	$ 0