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Other Commitments and Contingencies - Additional Information (Detail) gal in Millions, $ in Millions | 3 Months Ended
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Mar. 31, 2018 USD ($) gal
Commitments and Contingencies Disclosure [Abstract] |
Number of Years for Asset Management Agreement | 3 years
Number of years to purchase propane under contract | 6 years
Estimated current annual commitment | gal | 2.5
Debt Service Coverage Ratio | 1.25
Ratio based on average number of prior quarters | 6
Number of Propane Price Indices | 2
Ratios based on average of the prior quarters | 1 year 6 months
Funds from operations interest coverage ratio minimum times | 2
Total debt to capital maximum | 0.65
Number Of Years For Power Purchase Agreement | 20 years
Contract Duration | 20 years
Aggregate guaranteed amount | $ 72.7
Draws on letters of credit | $ 5.0

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- Definition Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=82913245&loc=d3e12069-110248 + Details
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