Equity Equity, Net Earnings (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2017 |
Sep. 30, 2016 |
Sep. 30, 2017 |
Sep. 30, 2016 |
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| Schedule of Capitalization, Equity [Line Items] | |||||||||||
| Net Income (Loss) Attributable To Partners | $ 97 | $ 88 | [1] | $ 299 | $ 263 | [1] | |||||
| General Partner | |||||||||||
| Schedule of Capitalization, Equity [Line Items] | |||||||||||
| Participating Securities, Distributed and Undistributed Earnings (Loss), Basic | 0 | 34 | 79 | 89 | |||||||
| Impact of General Partner Unit Issuance and Incentive Distribution Rights | [2] | 40 | 0 | 40 | 0 | ||||||
| Net Income (Loss) Attributable To Partners | 40 | 34 | 119 | 89 | |||||||
| Common | |||||||||||
| Schedule of Capitalization, Equity [Line Items] | |||||||||||
| Participating Securities, Distributed and Undistributed Earnings (Loss), Basic | 97 | 47 | 220 | 153 | |||||||
| Impact of General Partner Unit Issuance and Incentive Distribution Rights | [2] | (40) | 0 | (40) | 0 | ||||||
| Net Income (Loss) Attributable To Partners | $ 57 | $ 47 | $ 180 | $ 153 | |||||||
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