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Derivatives - Open Commodity Derivative Contracts - Refined Products (Detail) - Refined Products gal in Thousands | 3 Months Ended
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Mar. 31, 2017 gal
Exchange Traded |  |
Derivative [Line Items] |  |
Percentage of derivative contracts expiring in the period | 100.00% |
Derivative contract expiration date | Jun. 30, 2017 |
Exchange Traded | Long |  |
Derivative [Line Items] |  |
Notional contracts (in thousands of Total Gallons) | 254,058 | [1]
Exchange Traded | Short |  |
Derivative [Line Items] |  |
Notional contracts (in thousands of Total Gallons) | 133,098 | [1]
Over the Counter | Short |  |
Derivative [Line Items] |  |
Notional contracts (in thousands of Total Gallons) | 81,257 |
[1] | of the exchange-traded contracts expire in the second quarter of 2017.

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- Definition Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
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