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Financial Derivative Instruments - Fuel Hedging (Details) gal in Millions | Sep. 30, 2017 gal | [1]
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Remainder of Current Year |
Volume of Fuel Hedging |
Fuel Hedged (in gallons) | 320
2018 |
Volume of Fuel Hedging |
Fuel Hedged (in gallons) | 1,647
2019 |
Volume of Fuel Hedging |
Fuel Hedged (in gallons) | 1,377
Beyond 2019 |
Volume of Fuel Hedging |
Fuel Hedged (in gallons) | 358
[1] | Due to the types of derivatives utilized by the Company and different price levels of those contracts, these volumes represent the maximum economic hedge in place and may vary significantly as market prices fluctuate.

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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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