Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Loss Contingencies [Line Items]
Legal fees	$ 8	$ 12	$ 21	$ 27
Contractual Obligation	$ 83		$ 83
Contractual Obligation, Term of Contract	5 years		5 years
Litigation and regulatory matters | Minimum
Loss Contingencies [Line Items]
Estimate of possible loss	$ 2		$ 2
Litigation and regulatory matters | Maximum
Loss Contingencies [Line Items]
Estimate of possible loss	$ 17		$ 17