Goodwill and Identifiable Intangible Assets (Details) (USD $)			3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2012 Legend
Goodwill and Identifiable Intangible Assets
Goodwill	$ 138,947,000	$ 138,947,000
Accumulated amortization	(31,977,000)	(31,977,000)
Total goodwill	106,970,000	106,970,000	59,200,000
Mutual fund management advisory contracts	38,699,000	38,699,000
Mutual fund management subadvisory contracts	16,300,000	16,300,000
Total identifiable intangible assets	54,999,000	54,999,000
Total goodwill and identifiable intangible assets	161,969,000	161,969,000
Goodwill, annual impairment test
Impairment charges			42,400,000
Goodwill	$ 106,970,000	$ 106,970,000	$ 59,200,000