Revolving Credit Facility - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Line of Credit Facility Line Items
Revolving credit facility outstanding amount	$ 41,000,000		$ 41,000,000
Amortization of financing fees			$ 247,000	$ 398,000
Revolving Credit Facility
Line of Credit Facility Line Items
Term of credit facility (in years)			5 years
Maximum borrowing capacity	180,000,000		$ 180,000,000
Revolving credit facility maturity date			Aug. 18, 2020
Availability to be maintained under credit facility	$ 12,500,000		$ 12,500,000
Availability to be maintained under credit facility before restriction on investments, percentage	20.00%		20.00%
Covenant terms			The Revolving Credit Facility requires that we satisfy a fixed charge coverage ratio at any time that our availability is less than the greater of 10% of our calculated borrowing base or $12.5 million.
Revolving credit facility outstanding amount	$ 41,000,000		$ 41,000,000
Outstanding letters of credit	5,500,000		5,500,000
Availability under the credit facility	82,900,000		$ 82,900,000
Frequency of commitment fee payment			Payable quarterly
Revolving credit facility, description of variable rate basis			One month LIBOR
Interest expense	400,000	$ 200,000	$ 1,000,000	800,000
Commitment fees	100,000	100,000	300,000	400,000
Interest expense, debt	200,000		400,000
Amortization of financing fees	$ 100,000	$ 100,000	$ 300,000	$ 400,000
Revolving Credit Facility | Minimum
Line of Credit Facility Line Items
Availability to be maintained under credit facility, percentage	10.00%		10.00%
Revolving Credit Facility | Maximum
Line of Credit Facility Line Items
Commitment fees (as a percent)			0.25%