Condensed Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Condensed Consolidated Statement of Other Comprehensive Income (Loss) [Abstract]
Net income	$ 6.3	$ 8.8
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	(0.9)	(5.6)
Pension liabilities adjustment	0.0	(0.2)
Reclassification of adjustments included in net income [Abstract]
Periodic pension costs (included in compensation and benefits)	0.0	0.4
Reclassification adjustment for gains included in net income	0.0	0.4
Other comprehensive income (loss)	(0.9)	(5.4)
Comprehensive income	$ 5.4	$ 3.4