Income Taxes (Details) - USD ($) $ in Millions	2 Months Ended	3 Months Ended			8 Months Ended	9 Months Ended
	Jun. 08, 2016	Jun. 30, 2017	Jun. 30, 2016	[1]	Jun. 08, 2016	Jun. 30, 2017	Jun. 30, 2016	[1]	Sep. 30, 2016
Income Tax Contingency [Line Items]
Valuation allowance		$ 3.2				$ 3.2			$ 2.8
Increase in uncertain tax positions related to acquisition		1.3
Interest and penalties		1.9				1.9			$ 1.2
Successor
Income Tax Contingency [Line Items]
Income tax expense (benefit)		5.9	$ (1.3)			4.0	$ (1.3)
Pre-tax income (loss)		$ 16.1	$ (16.8)			$ 4.8	$ (18.4)
Predecessor
Income Tax Contingency [Line Items]
Income tax expense (benefit)	$ 1.1				$ 4.2
Pre-tax income (loss)	$ (19.1)				$ (9.7)

[1] The three and nine months ended June 30, 2016 include 22 days of the acquired business’ operating activities as a result of the consummation of the Business Combination on June 9, 2016.