Products and Services Revenues - Revenue from Geographical Region (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 7,933	$ 7,773	$ 7,839
North America
Disaggregation of Revenue [Line Items]
Total operating revenue	6,411	6,307	6,358
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total operating revenue	785	719	744
Latin America
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 737	$ 747	$ 737