Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Stock-Based Compensation - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 1.1	$ 1.4	$ 4.0	$ 4.5
Tax benefit from compensation expense	0.3	$ 0.4	1.0	$ 1.1
Share-based compensation, compensation cost not yet recognized	$ 6.5		$ 6.5
Share-based compensation, compensation cost not yet recognized, recognition period			2 years 4 months 24 days
Restricted Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of vested stock awards			$ 0.9		$ 1.9