Condensed Consolidated Statement of Comprehensive Income (Loss) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Condensed Consolidated Statement of Other Comprehensive Income (Loss) [Abstract]
Net income	$ (1.5)	$ (2.4)	$ (14.8)	$ (1.9)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment, net of tax	(0.3)	(0.1)	(0.6)	(0.2)
Pension liabilities adjustment, net of tax	0	0	0.4	0.1
Net unrealized loss on available-for-sale securities, net of tax	0.4	0.3	0.2	0.2
Reclassification of adjustment for gains included in net income [Abstract]
Foreign currency transaction adjustment (included in other income)	(0.1)	0	(0.1)	0
Realized gain on available-for-sale securities (included in trading gains, net)	0	0	(8.3)	0
Income tax expense from reclassification adjustments (included in income tax expense)	0	0	2.0	0
Reclassification adjustment for gains included in net income	(0.1)	0	(6.4)	0
Other comprehensive loss	0	0.2	(6.4)	0.1
Comprehensive income (loss)	$ 1.5	$ 2.6	$ 8.4	$ 2.0