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- Definition

Cash Paid On Derivative Settlement

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Cash Received On Derivative Settlement

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- Definition

Natural Gas Futures Nonmonetary Notional Amount Volume

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- Definition

Number Of Counterparties With Master Repurchase Agreements

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- Definition

Other Comprehensive Income Loss Adjustments AOCI Swap Agreements

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- Definition

Strike Price Per Gallon For The Propane Swap Agreements

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- Definition

Fair value, after offset of derivative liability, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226008-175313

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226006-175313

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=d3e41678-113959

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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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.

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Nominal volume used to calculate payments on a derivative instrument.

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No definition available.

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- Definition

The strike price on the price risk option contract such as a put option or a call option.

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- Definition

Current liabilities attributable to energy marketing activities (trading activities). Current energy marketing (trading activities) are when entities engage in both financial and physical trading to increase profits, manage their commodity price risk and enhance system reliability. They may trade electricity, coal, natural gas and oil. These entities typically use a variety of financial instruments, including forward contracts, options and swaps.

+ 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 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Carrying amount as of the balance sheet date of the asset arising from energy trading activities that involves the purchase and sale of energy under forward contracts at fixed and variable prices and the buying and selling of financial energy contracts that include exchange futures and options and over the counter options and swaps, which are expected to be converted into cash or otherwise disposed of within a year or the normal operating cycle, if longer.

+ 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 210.5-02.2)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The cash outflow for derivative instruments during the period, which are classified as financing activities, excluding those designated as hedging instruments.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3505-108585

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Derivative Instruments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016 USD ($) dekatherm / d Counterparty $ / gal gal	Dec. 31, 2015 USD ($) Counterparty $ / gal gal	Dec. 31, 2014 USD ($) $ / gal gal
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Volume \| gal	4,100,000
Other Comprehensive Income Loss Adjustments AOCI Swap Agreements		$ (735,000)
Energy Marketing Contract Liabilities, Current	$ 773,000	433,000
Mark-to-market energy assets	$ 823,000	153,000
Forward Contracts [Member]
Derivative [Line Items]
Accounts Payable Subject To Master Netting Arrangement		$ 431,000
Number Of Counterparties With Master Repurchase Agreements \| Counterparty	2	2
Put Option
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Volume \| gal	630,000	2,500,000	630,000
Payment to purchase call options	$ 33,000	$ 143,000	$ 128,000
Cash Received On Derivative Settlement		$ 239,000	$ 868,000
Call options
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Volume \| gal			1,300,000
Payment to purchase call options			$ 98,000
Propane Swap Agreement
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Volume \| gal	4,800,000	2,500,000	630,000
Cash Paid On Derivative Settlement		$ 484,000	$ 1,100,000
Mark To Market Energy Assets \| Propane [Member]
Derivative [Line Items]
Mark-to-market energy assets	$ 693,000
Mark To Market Energy Assets \| Future [Member]
Derivative [Line Items]
Natural Gas Futures Nonmonetary Notional Amount Volume \| dekatherm / d	3,727,500
Energy Marketing Contract Liabilities, Current	$ 113,000
Not Designated as Hedging Instrument [Member] \| Mark To Market Energy Assets \| Forward Contracts [Member]
Derivative [Line Items]
Mark-to-market energy assets	0	1,000
Not Designated as Hedging Instrument [Member] \| Mark To Market Energy Assets \| Propane Swap Agreement
Derivative [Line Items]
Mark-to-market energy assets	8,000
Not Designated as Hedging Instrument [Member] \| Mark-to-market energy liabilities \| Forward Contracts [Member]
Derivative [Line Items]
Energy Marketing Contract Liabilities, Current	0	1,000
Not Designated as Hedging Instrument [Member] \| Mark-to-market energy liabilities \| Natural Gas Futures [Member]
Derivative [Line Items]
Energy Marketing Contract Liabilities, Current	$ 773,000	0
Not Designated as Hedging Instrument [Member] \| Mark-to-market energy liabilities \| Future [Member]
Derivative [Line Items]
Natural Gas Futures Nonmonetary Notional Amount Volume \| dekatherm / d	1,267,500
Energy Marketing Contract Liabilities, Current	$ 773,000
Derivatives designated as fair value hedges \| Mark To Market Energy Assets \| Natural Gas Futures [Member]
Derivative [Line Items]
Mark-to-market energy assets	113,000	0
Derivatives designated as fair value hedges \| Mark To Market Energy Assets \| Put Option
Derivative [Line Items]
Mark-to-market energy assets	9,000	152,000
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	9,000
Derivatives designated as fair value hedges \| Mark To Market Energy Assets \| Propane Swap Agreement
Derivative [Line Items]
Mark-to-market energy assets	693,000
Derivatives designated as fair value hedges \| Mark-to-market energy liabilities \| Natural Gas Futures [Member]
Derivative [Line Items]
Energy Marketing Contract Liabilities, Current	0	109,000
Derivatives designated as fair value hedges \| Mark-to-market energy liabilities \| Propane Swap Agreement
Derivative [Line Items]
Energy Marketing Contract Liabilities, Current	$ 0	$ 323,000
Put Option Strike Price 1 [Member] \| Put Option
Derivative [Line Items]
Strike price of put option \| $ / gal	0.565	0.4950	1.0350
Put Option Strike Price 2 [Member] \| Put Option
Derivative [Line Items]
Strike price of put option \| $ / gal		0.4888	0.9975
Put Option Strike Price 3 [Member] \| Put Option
Derivative [Line Items]
Strike price of put option \| $ / gal		0.4500	0.9475
Put Option Strike Price 4 [Member] \| Put Option
Derivative [Line Items]
Strike price of put option \| $ / gal		0.4200
Strike Price 1 [Member] \| Call options
Derivative [Line Items]
Strike price of put option \| $ / gal			1.0875
Strike Price 2 [Member] \| Call options
Derivative [Line Items]
Strike price of put option \| $ / gal			1.0650
Strike Price 1 [Member] \| Propane Swap Agreement
Derivative [Line Items]
Strike Price Per Gallon For The Propane Swap Agreements \| $ / gal	0.5225	0.5200	1.1350
Strike Price 2 [Member] \| Propane Swap Agreement
Derivative [Line Items]
Strike Price Per Gallon For The Propane Swap Agreements \| $ / gal	0.5650	0.5950	1.0975
Strike Price 3 [Member] \| Propane Swap Agreement
Derivative [Line Items]
Strike Price Per Gallon For The Propane Swap Agreements \| $ / gal			1.0475