Income Taxes - Narrative (Details) $ in Millions	2 Months Ended	3 Months Ended		8 Months Ended	9 Months Ended
	Jun. 08, 2016 USD ($)	Jun. 30, 2016 USD ($) subsidiary	Jun. 30, 2015 USD ($)	Jun. 08, 2016 USD ($)	Jun. 30, 2016 USD ($) subsidiary	Jun. 30, 2015 USD ($)	Sep. 30, 2015 USD ($)
Operating Loss Carryforwards [Line Items]
Number of active subsidiaries | subsidiary		2			2
Unrecognized tax benefits potential decrease		$ 0.6			$ 0.6
Successor
Operating Loss Carryforwards [Line Items]
Income tax expense (benefit)		$ (1.3)			$ (1.3)
Effective income tax rate		7.70%			7.10%
Tax distributions associated with membership interests					$ 0.0
Pre-tax (loss)		$ (16.8)			(18.4)
Valuation allowance		4.2			4.2
Interest and penalties		$ 1.2			$ 1.2
Predecessor
Operating Loss Carryforwards [Line Items]
Income tax expense (benefit)	$ 1.1		$ 1.8	$ 4.2		$ 2.7
Tax distributions associated with membership interests				0.0		(0.1)
Pre-tax (loss)	$ (19.1)		$ 20.6	$ (9.7)		$ 14.2
Valuation allowance							$ 3.6
Interest and penalties							$ 1.1