Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	2 Months Ended	12 Months Ended
	Oct. 31, 2015	Nov. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Subsequent Event [Line Items]
Payment to acquire propane dealership			$ 21,130	$ 98,463	$ 1,376
Subsequent Event
Subsequent Event [Line Items]
Payment to acquire propane dealership		$ 7,600
Subsequent Event | Dividend Declared
Subsequent Event [Line Items]
Distribution declared	$ 0.095
Partners capital projected distribution amount on annualized basis	0.38
Minimum dividend distribution per unit	$ 0.0675
Percentage of distributions to common unit holders in excess of minimum quarterly distribution	90.00%
Percentage of distributions to general unit holders in excess of minimum quarterly distribution	10.00%
Amount to paid to common unit holders	$ 5,400
Amount to paid to the General Partner	100
Incentive distribution to the General Partner	90
Incentive distributions to management	$ 90
Dividend payable date	Nov. 05, 2015
Dividend record date	Oct. 28, 2015