Leases (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating leases	$ 23	$ 45
Short-term leases	3	7
Lease expense	26	52
Less: sublease income	0	0
Net lease cost	26	52
Cash payments included in the measurement of lease liabilities reported in operating cash flows	26	50
Right-of-use assets obtained in exchange for new lease liabilities	$ 28	$ 36
Weighted average discount rate (percent)	3.05%	3.05%
Weighted average remaining lease term (in years)	5 years 2 months 12 days	5 years 2 months 12 days