Derivatives (Derivatives Associated with Fixed Income Trading Activities) (Details) - USD ($)	Sep. 30, 2015	Sep. 30, 2014
Customer Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	$ 1,670,717,000	$ 1,731,047,000
Assets	82,905,000	69,878,000
Liabilities	1,512,000	5,778,000
Offsetting Upstream Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	1,670,717,000	1,731,047,000
Assets	1,512,000	5,778,000
Liabilities	82,905,000	69,878,000
Put Option [Member] | ShortMember
Derivative Instruments, Gain (Loss) [Line Items]
Notional		7,500,000
Assets		0
Liabilities		6,000
Put Option [Member] | LongMember
Derivative Instruments, Gain (Loss) [Line Items]
Notional	10,000,000	10,000,000
Assets	23,000	27,000
Liabilities	0	0
Forwards And Futures Purchased [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	3,458,150,000	1,866,521,000
Assets	15,561,000	2,047,000
Liabilities	353,000	614,000
Forwards And Futures Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	3,578,542,000	2,311,144,000
Assets	774,000	1,134,000
Liabilities	$ 15,568,000	$ 2,281,000