Condensed Consolidated Statement of Equity - 9 months ended Jun. 30, 2017 - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Sep. 30, 2016		89,286,936		0
Beginning balance at Sep. 30, 2016	$ 744.8	$ 0.0	$ 758.9	$ 0.0	$ (9.6)	$ (4.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock (in shares)		5,434
Forfeiture of restricted stock awards (in shares)		(10,753)
Shares associated with employee tax withholding for vesting of certain equity awards (in shares)		(9,576)		(9,576)
Shares associated with employee tax withholding for vesting of certain equity awards	(0.1)			$ (0.1)
Equity-based compensation	4.2		4.2
Comprehensive income:
Net income	0.8				0.8
Other comprehensive income	4.5					4.5
Ending balance (in shares) at Jun. 30, 2017		89,272,041		9,576
Ending balance at Jun. 30, 2017	$ 754.2	$ 0.0	$ 763.1	$ (0.1)	$ (8.8)	$ 0.0