BANK LOANS, NET, Originations, Purchases, and Sales (Details) (USD $)	3 Months Ended		6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Loans held for sale
Payments for Origination and Purchases of Loans Held-for-sale [Abstract]
Loans held for sale originated or purchased	$ 219,700,000	$ 255,400,000	$ 617,600,000	$ 548,300,000
Proceeds from Sale of Loans Held-for-sale [Abstract]
Proceeds from sale of loans held-for-sale	60,200,000	34,300,000	97,500,000	94,100,000
Loans held for investment
Purchases and sales of loans held for investment by portfolio segment [Abstract]
Purchases	107,534,000	110,546,000	473,590,000	265,471,000
Sales	25,500,000	70,350,000	32,360,000	131,323,000
Loans held for investment | C&I loans
Purchases and sales of loans held for investment by portfolio segment [Abstract]
Purchases	106,197,000	110,406,000	260,281,000	237,736,000
Sales	25,500,000	70,350,000	32,360,000	131,323,000
Loans held for investment | Residential mortgage loans
Purchases and sales of loans held for investment by portfolio segment [Abstract]
Purchases	1,337,000	140,000	213,309,000	27,735,000
Sales	0	0	0	0
Significant purchase in one portfolio			$ 207,300,000