Derivatives (Derivatives Associated with Capital Markets Trading Activities) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Customer Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	$ 1,775,287	$ 1,477,632
Assets	76,173	119,866
Liabilities	7,103	1,327
Offsetting Upstream Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	1,775,287	1,477,632
Assets	7,103	1,327
Liabilities	76,173	119,866
Put Option [Member] | Short [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional		2,500
Assets		0
Liabilities		2
Put Option [Member] | Long [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	10,000	2,500
Assets	29	5
Liabilities	0	0
Forwards And Futures Purchased [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	2,234,232	5,786,940
Assets	1,738	7,541
Liabilities	1,260	8,199
Forwards And Futures Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	2,607,585	5,923,867
Assets	2,277	8,090
Liabilities	$ 1,478	$ 8,381