Other Commitments and Contingencies - Additional Information (Detail) (USD $)	0 Months Ended		6 Months Ended
	May 31, 2013 gal	Mar. 02, 2011 claim	Jun. 30, 2013	Sep. 30, 2013	Apr. 09, 2013 contingency	Dec. 31, 2012
Other Contingencies And Commitments [Line Items]
Number of breaches claimed		3
Purchase period upon voter approval		12 months
Number of contingencies					0
Number of years to purchase propane under contract	6 years
Annual Estimate Of Volume Of Propane To Be Purchased	7,400,000
Total liabilities to tangible net worth minimum times			3.75
Fixed charge coverage ratio minimum times			1.5
Time to cure ratio			30 days
Funds from operations interest coverage ratio minimum times			2
Total debt to capital maximum			0.65
Maximum authorized liability under such guarantees and letters of credit			$ 45,000,000
Aggregate guaranteed amount			31,100,000
Draws on letters of credit			0
Liability for Uncertain Tax Positions, Noncurrent				300,000		300,000
Accrual For Taxes Other Than Income Contingencies				780,000		(82,000)
September 12, 2013 [Member]
Other Contingencies And Commitments [Line Items]
Amount of letter of credit to our current primary insurance company			1,000,000
December 2, 2013 [Member]
Other Contingencies And Commitments [Line Items]
Amount of letter of credit to our current primary insurance company			1,094,000
June 1, 2014 [Member]
Other Contingencies And Commitments [Line Items]
Amount of letter of credit to our current primary insurance company			304,000
TETLP Letter of Credit [Member] | Texas Eastern Transmission, LP [Member]
Other Contingencies And Commitments [Line Items]
Amount of letter of credit to our current primary insurance company			$ 2,300,000