Debt, Capital Lease Obligations and Other Financing - Schedule of Debt and Capital Lease Obligations (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Sep. 30, 2017
Debt Instrument [Line Items]
Long-term debt, gross	$ 150,000	$ 283,000
Capital lease and other financing obligations	37,882	30,901
Unamortized deferred financing fees	(1,313)	(794)
Total obligations	186,569	313,107
Less: current portion	(6,365)	(286,934)
Long-term debt and capital lease obligations, net of current portion	180,204	26,173
Senior Notes
Debt Instrument [Line Items]
Long-term debt, gross	150,000
Senior Notes \| 4.05% Senior Notes, due June 15, 2025
Debt Instrument [Line Items]
Long-term debt, gross	100,000
Senior Notes \| 4.22% Senior Notes, due June 15, 2028
Debt Instrument [Line Items]
Long-term debt, gross	50,000
Senior Notes \| 5.20% Senior Notes, due June 15, 2018
Debt Instrument [Line Items]
Long-term debt, gross		175,000
Line of Credit \| Borrowings under the credit facility
Debt Instrument [Line Items]
Long-term debt, gross	$ 0	$ 108,000

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer.

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Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer.

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Amount of long-term debt and capital lease obligations including current maturities.

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