Leases - Components of Lease Income (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Lessor, Lease, Description [Line Items]
Selling profit (charge)	$ 12	$ 26
Interest income	18	37
Operating lease income	24	$ 48
Sales-type Lease, Income, Comprehensive Income [Extensible List]		us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
Product revenue
Lessor, Lease, Description [Line Items]
Selling profit (charge)	24	$ 52
Cost of product
Lessor, Lease, Description [Line Items]
Selling profit (charge)	$ (12)	$ (26)