BANK LOANS, NET, Held for Sale and Held for Investment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2009		Sep. 30, 2008		Sep. 30, 2007
Held for sale and held for investment loan portfolios [Abstract]
Loans held for sale, net	$ 102,236	[1]	$ 6,114	[1]	$ 40,484	[1]	$ 524	[1]	$ 1,571	[1]
Loans held for investment:
C&I loans	4,100,939		3,232,723		3,079,916		3,411,963		1,820,471
CRE construction loans	29,087		65,512		163,951		346,691		123,664
CRE loans	742,889		937,669		1,080,160		842,766		841,152
Residential mortgage loans	1,756,486		2,015,331		2,396,995		2,599,042		1,933,061
Consumer loans	7,438		23,940		22,816		23,778		4,541
Total loans held for investment	6,636,839	[2]	6,275,175		6,743,838		7,224,240		4,722,889
Net unearned income and deferred expenses	(45,417)		(39,276)		(40,077)		(41,382)		(13,229)
Total loans held for investment, net	6,591,422	[1]	6,235,899	[1]	6,703,761	[1]	7,182,858	[1]	4,709,660	[1]
Total loans held for sale and investment	6,693,658		6,242,013		6,744,245		7,183,382		4,711,231
Allowance for loan losses	(145,744)		(147,084)		(150,272)		(88,155)		(47,022)
Bank loans, net	6,547,914		6,094,929		6,593,973		7,095,227		4,664,209
Associated percentage of each major loan category in loan portfolios [Abstract]
Loans held for sale, net (in hundredths)	2.00%	[1]	0.00%	[1]	1.00%	[1]	0.00%	[1]	0.00%	[1]
C&I loans (in hundredths)	61.00%		52.00%		46.00%		47.00%		38.00%
CRE construction loans (in hundredths)	0.00%		1.00%		2.00%		5.00%		3.00%
CRE loans (in hundredths)	11.00%		15.00%		16.00%		12.00%		18.00%
Residential mortgage loans (in hundredths)	26.00%		32.00%		35.00%		36.00%		41.00%
Consumer loans (in hundredths)	0.00%		0.00%		0.00%		0.00%		0.00%
Total loans held for sale and investment (in hundredths)	100.00%		100.00%		100.00%		100.00%		100.00%
Loans held for sale purchased or originated	354,900		251,800		208,900
Proceeds from sale of loans	93,200		121,400		77,000
Net gain from sale of loans held for sale	830		356		676
Loans held for investment [Member]
Purchases and sales of loans held for investment by portfolio segment [Abstract]
Purchases	250,850
Sales	57,209
Loans held for investment [Member] | C&I loans [Member]
Purchases and sales of loans held for investment by portfolio segment [Abstract]
Purchases	156,475
Sales	57,209
Loans held for investment [Member] | CRE [Member]
Purchases and sales of loans held for investment by portfolio segment [Abstract]
Purchases	2,630
Sales	0
Loans held for investment [Member] | Residential mortgage [Member]
Purchases and sales of loans held for investment by portfolio segment [Abstract]
Purchases	91,745
Sales	$ 0

[1] Net of unearned income and deferred expenses, which includes purchase premiums, purchase discounts, and net deferred origination fees and costs.

[2] Excludes any net unearned income and deferred expenses.