Long-Term Debt and Credit Facility - Additional Disclosures (Details)		3 Months Ended		6 Months Ended	12 Months Ended
	Sep. 30, 2016 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2017	Jun. 30, 2017	Dec. 31, 2017	May 10, 2013 USD ($)
Credit Facility
Line of Credit Facility [Line Items]
Limit on capital expenditures		$ 26,000,000
Covenant, percent of adjusted EBITDA which must be prepaid		25.00%
Credit facility ceiling value applicable to 25% of adjusting EBITDA which must be paid		$ 3,000,000.0
Covenant, maximum number of days from year end by which prepayment of 25% of adjusted EBITDA is due		75 days
Credit Facility | Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity						$ 75,000,000
Credit Facility | Line of Credit | Borrowings under revolving credit facility
Line of Credit Facility [Line Items]
Fixed coverage charge ratio requirement			1.00		1.10
Leverage ratio requirement		3.0		5.5
Undrawn availability required		$ 15,000,000
Credit facility, availability		74,900,000
Credit facility, available borrowing capacity, net of outstanding borrowings		$ 35,200,000
Credit facility, commitment fee percentage		0.25%
Credit facility, amount outstanding		$ 39,700,000
Credit Facility | Line of Credit | Borrowings under revolving credit facility | PNC Bank Base Rate
Line of Credit Facility [Line Items]
Base lending rate		4.75%
Credit facility, amount outstanding		$ 700,000
Credit facility, interest rate at period end		6.25%
Credit Facility | Line of Credit | Borrowings under revolving credit facility | LIBOR
Line of Credit Facility [Line Items]
Credit facility, amount outstanding		$ 39,000,000
Credit facility, interest rate at period end		4.38%
Credit Facility | Line of Credit | Borrowings under revolving credit facility | Minimum | PNC Bank Base Rate
Line of Credit Facility [Line Items]
Credit facility, variable percentage rate spread		1.50%
Credit Facility | Line of Credit | Borrowings under revolving credit facility | Minimum | LIBOR
Line of Credit Facility [Line Items]
Credit facility, variable percentage rate spread		2.50%
Credit Facility | Line of Credit | Borrowings under revolving credit facility | Maximum | PNC Bank Base Rate
Line of Credit Facility [Line Items]
Credit facility, variable percentage rate spread		2.00%
Credit Facility | Line of Credit | Borrowings under revolving credit facility | Maximum | LIBOR
Line of Credit Facility [Line Items]
Credit facility, variable percentage rate spread		3.00%
Credit Facility | Letter of Credit | Borrowings under revolving credit facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity						10,000,000
Credit Facility | Term loan
Line of Credit Facility [Line Items]
Debt, face amount	$ 10,000,000
Monthly principal payments	$ 200,000
Tenth Amendment to the Credit Facility | Line of Credit | Borrowings under revolving credit facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity						$ 75,000,000