Revenue Recognition - Contract Balances (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Schedule Of Contract Assets And Liabilities [Line Items]
Deferred customer acquisition costs	$ 113	$ 133
Accounts receivable, net	904	1,025
Unbilled revenues (included within Accounts receivable, net - Contracts with customers)	393	402
Deferred revenue	60	82
Deferred revenue from contract with customers	31	24
Revenue recognized	13	13
Accounts receivable, net - Contracts with customers
Schedule Of Contract Assets And Liabilities [Line Items]
Accounts receivable, net	866	1,002
Accounts receivable, net - Derivative instruments
Schedule Of Contract Assets And Liabilities [Line Items]
Accounts receivable, net	33	18
Accounts receivable, net - Affiliate
Schedule Of Contract Assets And Liabilities [Line Items]
Accounts receivable, net	$ 5	$ 5

Contract with Customer, Liability, Increase For Cash Payments Received

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- Definition

[Line Items] for Schedule Of Contract Assets And Liabilities [Table]

+ References

No definition available.

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- Definition

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

+ References

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-Publisher FASB
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Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer.

+ References

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- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

+ References

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- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

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Unbilled amounts due for services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the entity and, at a minimum, one other party. An example would be amounts associated with contracts or programs where the recognized revenue for performance thereunder exceeds the amounts billed under the terms thereof as of the date of the balance sheet.

+ References

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