CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 19.2	$ 14.6
Other comprehensive income (loss), net of tax:
Employee pension and postretirement benefits	0.8	0.5
Currency translation adjustments	(30.4)	(11.2)
Change in fair value of derivative instruments	0.0	0.2
Total other comprehensive income (loss), net of tax	(29.6)	(10.5)
Comprehensive income (loss)	$ (10.4)	$ 4.1