Guarantees (Details) (USD $)	6 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010
Financial Standby Letter of Credit [Member]
Guarantor obligations, current carrying value	$ 3,900,000
Guarantor obligations, maximum exposure, undiscounted	319,600,000
Indirect Guarantee of Indebtedness [Member]
Guarantor obligations, current carrying value	373,000
Notional amount of underlying interest rate swaps associated with risk participation agreements	79,400,000
Payment required if event of default on all contracts occurred	4,600,000
Risk participation agreement, minimum term, years	5
Risk participation agreement, maximum term, years	10
Guarantee Type, Other [Member]
Liability recorded for certain estimated litigation costs	3,100,000		4,400,000
Contribution to escrow account by Visa		400,000,000
Reduction in Indemnification Obligation	1,400,000
Indemnification Liability	$ 3,100,000		$ 4,400,000