Leases (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating leases	$ 23	$ 23	$ 71	$ 68
Short-term leases	1	2	2	9
Lease expense	24	25	73	77
Less: sublease income	0	0	0	0
Net lease cost	24	25	73	77
Cash payments to settle a lease liability reported in cash flows	27	27	82	77
Right-of-use assets obtained in exchange for new lease liabilities	$ 8	$ 14	$ 26	$ 50
Weighted average discount rate (percent)	2.86%	3.04%	2.86%	3.04%
Weighted average remaining lease term (in years)	4 years 10 months 24 days	5 years 2 months 12 days	4 years 10 months 24 days	5 years 2 months 12 days