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Derivative Instruments - Effects of Gains and Losses from Derivative Instruments on Condensed Consolidated Financial Statements (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Derivative, Gain (Loss) on Derivative, Net | $ 1,209 | $ 767 | $ 4,997 | $ 2,837
Cost of Sales [Member] | Derivatives designated as hedging instrument [Member] | Propane Swap Agreement [Member] |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Derivative, Gain (Loss) on Derivative, Net | 116 | 290 | 1,581 | 1,148
Other Comprehensive Income (Loss) [Member] | Derivatives designated as hedging instrument [Member] | Natural Gas Swaps [Member] |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax | 0 | 1,612 | 0 | 2,376
Other Comprehensive Income (Loss) [Member] | Derivatives designated as hedging instrument [Member] | Propane Swap Agreement [Member] |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax | 1,022 | (1,139) | 3,385 | (624)
Other Comprehensive Income (Loss) [Member] | Derivatives designated as hedging instrument [Member] | Interest Rate Swap [Member] |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax | 37 | 0 | (14) | 0
Other Comprehensive Income (Loss) [Member] | Derivatives designated as hedging instrument [Member] | Natural Gas Futures [Member] |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax | 0 | 4 | 0 | (63)
Interest Expense [Member] | Derivatives designated as hedging instrument [Member] | Interest Rate Swap [Member] |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Derivative, Gain (Loss) on Derivative, Net | $ 34 | $ 0 | $ 45 | $ 0

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- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959 + Details
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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 No definition available. + Details
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- Definition Amount before tax, after reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580 + Details
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