Leases - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssets	us-gaap:OtherAssets
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent
Operating lease, right-of-use assets	$ 97	$ 121
Lease liabilities	$ 108	$ 135
Minimum
Lessee, Lease, Description [Line Items]
Operating lease, contract term	1 year
Operating lease, renewal term	3 years
Maximum
Lessee, Lease, Description [Line Items]
Operating lease, contract term	8 years
Operating lease, renewal term	5 years