Other Income (Expenses) - Narrative (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Other Income and Expenses [Abstract]
Non-investment interest income	$ 3.2
Proceeds from Sale of Available-for-sale Securities	578.1	477.5	247.1
Net gains (losses) on trading investment securities	24.0	(9.1)	17.8
Net gains (losses) on trading investment securities of consolidated SIPs	$ 22.9	$ (39.0)	$ (2.3)

The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

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+ Details

- Definition

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of trading securities held at each balance sheet date, that was included in earnings for the period. Trading securities are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) and the change in net unrealized holding gain (loss) is included in earnings for the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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