Leases (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating leases	$ 22
Short-term leases	4
Lease expense	26
Net lease cost	26
Cash payments included in the measurement of lease liabilities reported in operating cash flows	24
Right-of-use assets obtained in exchange for new lease liabilities	$ 8
Weighted average discount rate (percent)	3.07%
Weighted average remaining lease term (in years)	5 years 2 months 12 days