Accumulated Other Comprehensive Income (Loss) Rollforward (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, net	$ (10.1)		$ (10.1)		$ (6.4)
Other comprehensive loss	(2.8)	0	(3.7)	(6.4)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, net	(8.0)		(8.0)		(4.1)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			(3.9)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			0
Other comprehensive loss			(3.9)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, net	(2.6)		(2.6)		(2.8)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			0.2
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			0
Other comprehensive loss			0.2
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, net	0.5		0.5		0.5
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			0
Other comprehensive loss			0
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, net	(10.1)		(10.1)		(6.4)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			(3.7)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			0
Other comprehensive loss			$ (3.7)