Earnings per Share - EPS Reconciliation (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Income from continuing operations	$ 13.0	$ 7.7	$ 22.4	$ 10.1
Undistributed Earnings Allocated to Participating Securities - Continuing Operations	(0.3)	(0.2)	(0.5)	(0.3)
Income from continuing operations allocated to common shareholders	12.7	7.5	21.9	9.8
Loss from discontinued operations, net of tax	0	(0.2)	0	(0.1)
Undistributed Earnings Allocated to Participating Securities - Discontinued Operations	0	0	0	0
Income from discontinued operations allocated to common shareholders	0	(0.2)	0	(0.1)
Diluted net income	13.0	7.5	22.4	10.0
Less: Allocation to participating securities	(0.3)	(0.2)	(0.5)	(0.3)
Diluted net income allocated to common shareholders	$ 12.7	$ 7.3	$ 21.9	$ 9.7
Weighted average number of common shares outstanding	18,599,011	18,609,550	18,546,377	18,627,383
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	358,769	345,578	196,656	646,770
Diluted weighted-average shares	18,957,780	18,955,128	18,743,033	19,274,153

Diluted net income allocated to common shareholders (diluted net income less allocation to participating securities).

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Income from continuing operations allocated to common shareholders represents income from continuing operations attributable to shareholders less allocation to participating securities plus interest on convertible debt less the allocation of the earnings from the interest on convertible debt to participating securities.

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Income from discontinued operations allocated to common shareholders represents income from discontinued operations less allocation to participating securities.

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Undistributed Earnings Allocated to Participating Securities - Continuing Operations represents earnings from continuing operations allocated (not distributed) to participating securities under the two-class method to the extent that participating securities may share in earnings as if all of the earnings for the period had been distributed.

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Undistributed Earnings Allocated to Participating Securities - Discontinued Operations represents earnings from discontinued operations allocated (not distributed) to participating securities under the two-class method to the extent that participating securities may share in earnings as if all of the earnings for the period had been distributed.

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Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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Amount of income (loss) from a disposal group, net of income tax, reported as a separate component of income before extraordinary items after deduction or consideration of the amount allocable to noncontrolling interests. Includes, net of tax, income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Net Income or Loss Available to Common Stockholders plus adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.

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Earnings allocated (not distributed) to participating securities under the two-class method to the extent that participating securities may share in earnings as if all of the earnings for the period had been distributed.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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