Lease Commitments Lease Commitments - Right-of-Use Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Other assets, non-current	$ 1,415
Other liabilities and deferred revenue, current	367	$ 0
Other liabilities and deferred revenue, non-current	1,047	$ 0
Total operating lease liabilities	1,414
Total finance lease liabilities	177
Other Current Liabilities
Lessee, Lease, Description [Line Items]
Other liabilities and deferred revenue, current	367
Other Noncurrent Liabilities
Lessee, Lease, Description [Line Items]
Other liabilities and deferred revenue, non-current	1,047
Property, Plant and Equipment
Lessee, Lease, Description [Line Items]
Property and equipment, gross	252
Accumulated depreciation	(43)
Property and equipment, net	209
Operating Segments | Debt | Automotive
Lessee, Lease, Description [Line Items]
Automotive debt payable within one year	92
Automotive long-term debt	$ 85