Net Income per Unit (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
Feb. 14, 2018	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share Basic [Line Items]
Income (loss) from continuing operations		$ (78)	$ 12
Distribution to preferred units		(2)
Net income (loss) and comprehensive income (loss)		(315)	1
Incentive distribution rights	$ 21	18	21
Distributions on nonvested phantom unit awards		1	2
Loss from discontinued operations, net of income taxes		$ (237)	$ (11)
Weighted average limited partner units outstanding:
Income (Loss) from Continuing Operations, Net of Tax, Per Outstanding Limited Partnership Unit, Diluted		$ (1.11)	$ (0.11)
Income (Loss) from Discontinued Operations, Net of Tax, Per Outstanding Limited Partnership Unit, Diluted		$ (2.63)	$ (0.11)
Common Units [Member]
Earnings Per Share Basic [Line Items]
Income from continuing operations allocated to limited partners		$ (99)	$ (11)
Weighted average limited partner units outstanding:
Common - basic (in shares)		89,753,950	98,609,608
Common - equivalents (in shares)		517,801	106,350
Common - diluted (in shares)		90,271,751	98,715,958
Income (Loss) from Continuing Operations, Per Outstanding Limited Partnership Unit, Basic, Net of Tax		$ (1.11)	$ (0.11)
Income (Loss) from Discontinued Operations, Net of Tax, Per Outstanding Limited Partnership Unit, Basic		$ (2.63)	$ (0.11)
Series A Preferred Units [Member]
Earnings Per Share Basic [Line Items]
Distribution to preferred units		$ 2	$ 0

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Amount of paid and unpaid cash, stock, and paid-in-kind (PIK) dividends declared and applicable to holders of share-based compensation, for example, but not limited to, non-vested shares, stock options, or restricted stock units.

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Amount of incentive obligation paid in cash or stock during the period to a limited liability corporation managing member or limited partnership general partner.

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Amount after tax of income (loss) from continuing operations attributable to the parent.

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Per unit of ownership amount after tax of income (loss) from continuing operations available to limited partnership (LP) unit-holder and units that would have been outstanding assuming the issuance of limited partner units for dilutive potential units outstanding.

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Amount after tax of income (loss) from a discontinued operation attributable to the parent. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Total distributions to each class of partners (i.e., general, limited and preferred partners).

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Weighted average number of limited partnership units outstanding determined by relating the portion of time within a reporting period that limited partnership units have been outstanding to the total time in that period.

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