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v3.21.2

Borrowing Arrangements (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020 | Sep. 30, 2020 | Sep. 30, 2019
Outstanding letter of credit accrued fees and expenses | $ 1.7 |  | $ 1.7 |  |  |
Cash and cash equivalents | 228.6 | $ 170.7 | 228.6 | $ 170.7 | $ 208.9 | $ 176.7
Future maturities of outstanding borrowings |  |  |  |  |  |
Outstanding letters of credit | 15.0 |  | 15.0 |  |  |
Gain (Loss) on Extinguishment of Debt | 16.7 | $ 0.0 | 16.7 | $ 0.0 |  |
Payment for Debt Extinguishment or Debt Prepayment Cost | 12.4 |  |  |  |  |
Write off of Deferred Debt Issuance Cost | 4.3 |  |  |  |  |
Domestic Line of Credit [Member] |  |  |  |  |  |
Revolving credit facility amount | $ (175.0) |  | $ (175.0) |  |  |
Line of Credit Facility, Interest Rate at Period End | 200.00% |  | 200.00% |  |  |
Excess availability reduced by outstanding borrowings, outstanding letters of credit and accrued fees and expenses | $ 145.1 |  | $ 145.1 |  |  |
Future maturities of outstanding borrowings |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity | 175.0 |  | 175.0 |  |  |
Potential increase size of the credit facility by an additional amount |  |  | 150.0 |  |  |
Aggregate commitments availability |  |  | $ 17.5 |  |  |
Aggregate commitments availability, percentage |  |  | 10.00% |  |  |
Line of Credit Facility, Remaining Borrowing Capacity | 145.1 |  | $ 145.1 |  |  |
Swing Line Loans [Member] |  |  |  |  |  |
Revolving credit facility amount | (25.0) |  | (25.0) |  |  |
Future maturities of outstanding borrowings |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity | 25.0 |  | 25.0 |  |  |
Letters Of Credit Outstanding [Member] |  |  |  |  |  |
Revolving credit facility amount | (60.0) |  | (60.0) |  |  |
Future maturities of outstanding borrowings |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity | $ 60.0 |  | $ 60.0 |  |  |
4.0% Senior Notes [Member] |  |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | 4.00% |  | 4.00% |  |  |
Future maturities of outstanding borrowings |  |  |  |  |  |
Payments of debt issuance costs | $ 5.5 |  |  |  |  |
Financial Liabilities Fair Value Disclosure | $ 461.3 |  | $ 461.3 |  |  |
5.5% Notes |  |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | 5.50% |  | 5.50% |  |  |
Minimum [Member] | Domestic Line of Credit [Member] |  |  |  |  |  |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage |  |  | 37.50% |  |  |
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | Long-term Debt [Member] |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  | 100.00% |  |  |
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | Domestic Line of Credit [Member] |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  | 200.00% |  |  |
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member] | Long-term Debt [Member] |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  | 125.00% |  |  |
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member] | Domestic Line of Credit [Member] |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  | 225.00% |  |  |

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