Leases - Other Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Other information
Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases	$ 14	$ 13
Right-of-use assets obtained in exchange for lease liabilities: Operating leases	$ 21	$ 8
Weighted average remaining lease term (years): Operating leases	6 years 3 months 18 days		5 years 6 months
Weighted average discount rate: Operating leases	4.60%		4.90%