Restructuring, Facility Consolidation and Severance Charges (Restructuring Charges) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	$ 0	$ 31	$ 0	$ 114
Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	0	31	0	114
Restructuring Charges | Western Hemisphere
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	0	17	0	58
Restructuring Charges | Eastern Hemisphere
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	0	12	0	29
Restructuring Charges | Corporate and Other
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	$ 0	$ 2	$ 0	$ 27