Equity, Equity Activity (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2016 |
[2] | Jun. 30, 2017 |
Jun. 30, 2016 |
[2] | ||||||||
| Changes in carrying amount of Equity | |||||||||||||
| Balance at December 31, 2016 | $ 1,542 | ||||||||||||
| Proceeds from issuance of units, net of issuance costs | 287 | ||||||||||||
| Distributions to unitholders and general partner (a) | [1] | (280) | |||||||||||
| Net earnings attributable to partners | $ 110 | $ 83 | 202 | $ 175 | |||||||||
| Contributions (b) | [3] | 33 | |||||||||||
| Other | 3 | ||||||||||||
| Balance at June 30, 2017 | 1,787 | 1,787 | |||||||||||
| Common | |||||||||||||
| Changes in carrying amount of Equity | |||||||||||||
| Balance at December 31, 2016 | 1,608 | ||||||||||||
| Proceeds from issuance of units, net of issuance costs | 281 | ||||||||||||
| Distributions to unitholders and general partner (a) | [1] | (195) | |||||||||||
| Net earnings attributable to partners | 125 | ||||||||||||
| Contributions (b) | [3] | 31 | |||||||||||
| Other | (2) | ||||||||||||
| Balance at June 30, 2017 | 1,848 | 1,848 | |||||||||||
| General Partner | |||||||||||||
| Changes in carrying amount of Equity | |||||||||||||
| Balance at December 31, 2016 | (66) | ||||||||||||
| Proceeds from issuance of units, net of issuance costs | 6 | ||||||||||||
| Distributions to unitholders and general partner (a) | [1] | (85) | |||||||||||
| Net earnings attributable to partners | 77 | ||||||||||||
| Contributions (b) | [3] | 2 | |||||||||||
| Other | 5 | ||||||||||||
| Balance at June 30, 2017 | $ (61) | $ (61) | |||||||||||
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