Products and Services Revenues - Assets from Geographic Region (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	$ 28,576	$ 29,098
North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	23,511	24,144
Europe, Middle East and Africa
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	3,059	2,842
Latin America
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	$ 2,006	$ 2,112