Equity-Based Compensation - Fair Value of Awards Vested (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Strategic Performance Units (SPUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units vested (in shares)	98,295	93,551	114,499
Fair Value of Units Vested	$ 7	$ 4	$ 7
Unit-Based Liabilities Paid	$ 4	$ 7	$ 8
Phantom Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units vested (in shares)	126,681	96,974	147,840
Fair Value of Units Vested	$ 4	$ 3	$ 5
Unit-Based Liabilities Paid	$ 5	$ 5	$ 5

Amount of cash paid related to share-based compensation liabilities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

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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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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