Amount, after accumulated amortization, of debt discount (premium).

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Name:	us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Long-Term Debt - Schedule of Long-Term Debt (Parenthetical) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Series B Term Loan
Debt Instrument [Line Items]
Debt, original issue discount	$ 2,712
First Lien Credit Facility Term Loans
Debt Instrument [Line Items]
Debt, original issue discount		$ 1,777
Second Lien Credit Facility Term Loans
Debt Instrument [Line Items]
Debt, original issue discount		$ 706