CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) (USD $)	Sep. 30, 2011	Sep. 30, 2010
Equity
Preferred stock, par value (in dollars per share)	$ 0.10	$ 0.10
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	350,000,000	350,000,000
Common stock, shares issued (in shares)	130,670,086	128,620,429
Shares exchangeable into common stock (in shares)	0	243,048
Treasury stock, shares (in shares)	4,263,029	3,918,492