Other Comprehensive Income (Schedule of Changes in AOCL by Component) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Other comprehensive income (loss)
Total Other Comprehensive Income (Loss), net of tax	$ (9.4)	$ (22.1)
Accumulated other comprehensive loss
Beginning balance	1,146.9
Net activity	(9.4)	(22.1)
Ending balance	1,136.7
Available-for-Sale Securities and Currency Hedges [Member]
Other comprehensive income (loss)
Prior to reclassification	$ 0.2	$ (0.6)
Reclassification from
Pre-tax	$ 0.2	$ (0.6)
Tax effect	(0.1)	0.2
Total Other Comprehensive Income (Loss), net of tax	$ 0.1	$ (0.4)
Accumulated other comprehensive loss
Beginning balance
Net activity	$ 0.1	$ (0.4)
Ending balance	0.1	(0.4)
Foreign Currency Translation Adjustment [Member]
Other comprehensive income (loss)
Prior to reclassification	$ (10.2)	$ (22.6)
Reclassification from
Pre-tax	$ (10.2)	$ (22.6)
Tax effect
Total Other Comprehensive Income (Loss), net of tax	$ (10.2)	$ (22.6)
Accumulated other comprehensive loss
Beginning balance	(92.8)	(34.2)
Net activity	(10.2)	(22.6)
Ending balance	$ (103.0)	(56.8)
Pension and Postretirement Defined Benefit Plan Items [Member]
Other comprehensive income (loss)
Prior to reclassification		0.1
Reclassification from	$ 1.1	1.3
Pre-tax	1.1	1.4
Tax effect	(0.4)	(0.5)
Total Other Comprehensive Income (Loss), net of tax	0.7	0.9
Accumulated other comprehensive loss
Beginning balance	(48.0)	(39.9)
Net activity	0.7	0.9
Ending balance	(47.3)	(39.0)
Accumulated Other Comprehensive Income (Loss) [Member]
Other comprehensive income (loss)
Prior to reclassification	(10.0)	(23.1)
Reclassification from	1.1	1.3
Pre-tax	(8.9)	(21.8)
Tax effect	(0.5)	(0.3)
Total Other Comprehensive Income (Loss), net of tax	(9.4)	(22.1)
Accumulated other comprehensive loss
Beginning balance	(140.8)	(74.1)
Net activity	(9.4)	(22.1)
Ending balance	$ (150.2)	$ (96.2)