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Maximum excess availability level at which financial maintenance covenants would apply, as a percentage of aggregate commitments.

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Total other amounts reducing excess availability.

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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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Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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The effective interest rate at the end of the reporting period.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Borrowing Arrangements (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended			84 Months Ended
	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Nov. 25, 2021
Agreement termination date		Jul. 13, 2021
Unsecured Debt		$ 451.6	$ 486.5
Loss on early extinguishment of debt	$ (6.2)	6.5	0.0	$ 0.0
Future maturities of outstanding borrowings
CY plus 1		0.7
CY plus 2		0.6
CY plus 3		0.3
CY plus 4		0.0
CY plus 5		0.0
Payments of Financing Costs		6.9	1.0	$ 1.2
Revolving Credit Facility [Member]
Revolving credit facility amount		175.0	225.0
Potential increase size of the credit facility by an additional amount		$ 150.0
Line of Credit Facility, Interest Rate at Period End		12500.00%
Aggregate commitments availability		$ 17.5
Aggregate commitments availability, percentage		10.00%
Outstanding letter of credit accrued fees and expenses		$ 18.3
Excess availability reduced by outstanding borrowings, outstanding letters of credit and accrued fees and expenses		125.0
Unsecured Debt		$ 0.0	0.0
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage		2500.00%
Loss on early extinguishment of debt		$ (0.3)
Bonds [Member]
Debt Instrument, Interest Rate, Effective Percentage		5.50%
Future maturities of outstanding borrowings
Financial Liabilities Fair Value Disclosure		$ 452.3
Unsecured Debt [Member]
Deferred Finance Costs, Noncurrent, Gross		6.6
Unsecured Debt		450.0	0.0
Swing Line Loans [Member]
Revolving credit facility amount		25.0
Letter Of Credit [Member]
Revolving credit facility amount		$ 60.0
Secured Debt [Member]
Borrowing rate in addition to LIBOR		25000.00%
Unsecured Debt		$ 0.0	$ 484.8
Long-term Debt, Gross		$ 500.0
London Interbank Offered Rate (LIBOR) [Member] \| Minimum [Member] \| Revolving Credit Facility [Member]
Borrowing rate in addition to LIBOR		12500.00%
London Interbank Offered Rate (LIBOR) [Member] \| Minimum [Member] \| Secured Debt [Member]
Debt Instrument, Interest Rate, Stated Percentage		0.75%
London Interbank Offered Rate (LIBOR) [Member] \| Maximum [Member] \| Revolving Credit Facility [Member]
Borrowing rate in addition to LIBOR		15000.00%
Base Rate [Member] \| Minimum [Member] \| Revolving Credit Facility [Member]
Borrowing rate in addition to LIBOR		2500.00%
Base Rate [Member] \| Maximum [Member] \| Revolving Credit Facility [Member]
Borrowing rate in addition to LIBOR		5000.00%
Scenario, Forecast [Member] \| Secured Debt [Member]
Agreement termination date					Nov. 25, 2021