Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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

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- Definition

Aggregate notional amount that was terminated specified by the derivative(s).

+ References

No definition available.

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- Definition

Interest rate received under the terms of the interest rate swap agreements.

+ References

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The amount of cash received during the period on settlement of a hedge.

+ References

No definition available.

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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.

+ References

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- Definition

Nominal volume used to calculate payments on a derivative instrument.

+ References

No definition available.

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- Definition

The amount of cash or securities placed with a broker or counterparty as security for a trading or derivatives securities position which was partially obtained with funds provided by the broker dealer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.8,17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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DERIVATIVES AND RISK MANAGEMENT ACTIVITIES Narrative (Details) bbl in Millions			1 Months Ended	3 Months Ended
	Mar. 31, 2018 USD ($) bbl	Dec. 31, 2017 USD ($) bbl	Apr. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)
Derivative [Line Items]
Margin deposit	$ 400,000	$ 300,000		$ 400,000
Interest rate swaps \| Cash Flow Hedges
Derivative [Line Items]
Interest rate swaps interest rate received				receive a rate based on the three-month USD LIBOR
Notional amount of forward-starting interest rate swaps	$ 600,000,000	$ 600,000,000		$ 600,000,000
Commodity contracts
Derivative [Line Items]
Notional amount of commodity contracts, volume (in barrels) \| bbl	1.7	1.2
Logistics Notes due 2018 [Member]
Derivative [Line Items]
Stated interest rate	7.65%			7.65%
Subsequent Event [Member]
Derivative [Line Items]
Cash received from termination of interest rate swaps			$ 8,000,000
Subsequent Event [Member] \| Interest rate swaps \| Cash Flow Hedges
Derivative [Line Items]
Notional amount of forward-starting interest rate swaps terminated			$ 350,000,000.0