Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of increase (decrease) in partners' capital account for unit-based payment arrangement issued by partnership. Partner includes, but is not limited to, general, limited and preferred partners.

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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Percentage of vesting of award under share-based payment arrangement.

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Intrinsic value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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Unit-Based Compensation - Additional Information Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unit-based compensation	$ 13	$ 12	$ 24
Phantom Share Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of phantom units vested in period	14	12	$ 9
Unrecognized compensation expense from nonvested phantom units	$ 32
Weighted average period over which compensation expense for nonvested phantom units will be recognized	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested	$ 62	$ 57
Phantom Share Units (PSUs) [Member] \| Share-based Payment Arrangement, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of phantom unit awards	60.00%
Vesting period for phantom unit awards	3 years
Phantom Share Units (PSUs) [Member] \| Share-based Payment Arrangement, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of phantom unit awards	40.00%
Vesting period for phantom unit awards	5 years