Leases (Consolidated statement of operations) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Operating Leased Assets [Line Items]
Total operating lease expense	$ 54
Operating lease, expense, leases less than one year	6
Operating lease, expense, variable leases	2
Selling, general and administrative
Operating Leased Assets [Line Items]
Total operating lease expense	51
Service revenue | Cost of product sales
Operating Leased Assets [Line Items]
Total operating lease expense	2
Product revenue | Cost of product sales
Operating Leased Assets [Line Items]
Total operating lease expense	$ 1