Leases (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Leases [Abstract]
Operating leases	$ 23	$ 24
Short-term leases	0	0
Lease expense	23	24
Less: sublease income	0	0
Net lease cost	23	24
Cash payments to settle a lease liability reported in cash flows	26	27
Right-of-use assets obtained in exchange for new lease liabilities	$ 12	$ 14
Weighted average discount rate (percent)	2.46%	2.97%
Weighted average remaining lease term (in years)	4 years 10 months 24 days	5 years