Products and Services Revenues - Assets from Geographic Region (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	$ 29,098	$ 32,291
North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	24,144	27,520
Europe, Middle East and Africa
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	2,842	2,765
Latin America
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	$ 2,112	$ 2,006