Income Taxes - Unrecognized tax benefits (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2014 |
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| Activity within the reserve for unrecognized tax benefits | |||
| Balance at the beginning of the period | $ 7.8 | $ 8.4 | $ 6.4 |
| Additions for tax positions related to the current year | 0.2 | 0.6 | 2.5 |
| Additions for tax positions of prior years | 1.7 | 0.8 | 0.0 |
| Reductions for tax positions of prior years | (2.0) | (2.0) | (0.3) |
| Settlements | 0.0 | 0.0 | (0.2) |
| Balance at the end of the period | 7.7 | 7.8 | $ 8.4 |
| Gross unrecognized tax benefits, if recognized would impact the effective tax rate | 7.7 | 7.8 | |
| Additional amounts recognized (released) for interest and penalties | 0.7 | 0.2 | |
| Other amounts accrued for interest and penalties | 1.3 | $ 0.9 | |
| Amount by which the unrecognized tax benefits could increase or decrease over the next 12 months | $ 1.0 | ||
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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- Definition The amount of the unrecognized tax benefit of a position taken for which it is reasonably possible that the total amount thereof will significantly increase or decrease within twelve months of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of expense for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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