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Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Taxes
Effective income tax rate (as a percent)	70.60%	31.00%	9084.70%	32.50%
U.S. federal statutory rate (as a percent)						35.00%
Income tax benefit related to new tax act	$ 1.4		$ 501.8
Forecast
Income Taxes
U.S. federal statutory rate (as a percent)					24.50%

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- Definition

Amount of reasonable estimate for income tax expense (benefit) from effect of Tax Cuts and Jobs Act of 2017 for which accounting for tax effect is incomplete.

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- Definition

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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