Subsequent Events - Additional Information (Detail) - USD ($)		1 Months Ended	3 Months Ended
	Jul. 30, 2015	Jul. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Jun. 30, 2014
8.875% Senior Notes
Subsequent Event [Line Items]
Interest on senior notes				8.875%	8.875%
Outstanding senior notes				$ 125,000,000
Subsequent Event | 8.875% Senior Notes
Subsequent Event [Line Items]
Interest on senior notes		8.875%	8.875%
Outstanding senior notes		$ 125,000,000	$ 125,000,000
Redemption price percentage		104.438%	104.438%
Subsequent Event | Third Amendment
Subsequent Event [Line Items]
Non Seasonal maximum borrowing capacity under revolving credit facility	$ 300,000,000		$ 300,000,000
Maximum borrowing capacity (heating season December to April) under revolving credit facility	$ 450,000,000		$ 450,000,000
Subsequent Event | Third Amendment | Revolving Credit Facility
Subsequent Event [Line Items]
Debt maturity period			5 years
Subsequent Event | Third Amendment | $100 million Term Loan
Subsequent Event [Line Items]
Debt maturity period	5 years		5 years
Senior secured term loan			$ 100,000,000
Subsequent Event | Third Amendment | 8.875% Senior Notes
Subsequent Event [Line Items]
Interest on senior notes	8.875%
Outstanding senior notes	$ 125,000,000
Redemption price percentage	104.438%
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		$ 5,400,000
Amount to paid to the General Partner		100,000
Incentive distribution to the General Partner		90,000
Incentive distributions to management		$ 90,000
Dividend payable date		Aug. 07, 2015
Dividend record date		Jul. 30, 2015