Guarantees (Details) (USD $)	Jun. 30, 2012
Financial Standby Letter Of Credit [Member]
Guarantor Obligations [Line Items]
Guarantor obligations, net liability	$ 5,700,000
Guaranteed maximum potential future payments	370,200,000
Risk Participation Agreement [Member] | Indirect Guarantee Of Indebtedness [Member]
Guarantor Obligations [Line Items]
RPA's, minimum in years	5
RPA's, maximum in years	10
Notional amount of underlying interest rate swaps associated with risk participation agreements	36,100,000
Payment required if event of default on all contracts occurred	3,400,000
Not Designated as Hedging Instrument [Member] | Risk Participation Agreement [Member] | Indirect Guarantee Of Indebtedness [Member]
Guarantor Obligations [Line Items]
Derivative Liabilities	$ 109,000