Leases (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Leases [Abstract]
Operating leases	$ 24	$ 23	$ 48	$ 45
Short-term leases	1	3	1	7
Lease expense	25	26	49	52
Less: sublease income	0	0	0	0
Net lease cost	25	26	49	52
Cash payments to settle a lease liability reported in cash flows	28	26	55	50
Right-of-use assets obtained in exchange for new lease liabilities	$ 4	$ 28	$ 18	$ 36
Weighted average discount rate (percent)	2.94%	3.05%	2.94%	3.05%
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