Debt - Senior Notes (Details) - Senior Notes $ in Millions	12 Months Ended
Dec. 31, 2020 USD ($)
Debt Instrument [Line Items]
Debt instrument, repurchased face amount	$ 156
Debt repurchased, principal	93
Gain on repurchase of debt	$ 63

Amount of gain (loss) from the difference between the repurchase price of a debt instrument initially issued by the entity and the net carrying amount of the debt at the time of its repurchase.

No definition available.

Name:	us-gaap_GainLossOnRepurchaseOfDebtInstrument
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration