Financial Derivatives (Internal Credit Ratings of Risk Participation Agreements Sold) (Details) (Risk Participation Agreements Sold [Member])	6 Months Ended		12 Months Ended
	Jun. 30, 2011		Dec. 31, 2010
Risk Level, High [Member]
Internal Credit Ratings of Risk Participation Agreements Sold	2%	[1]	5%	[1]
Risk Level, Low [Member]
Internal Credit Ratings of Risk Participation Agreements Sold	98%	[2]	95%	[2]

[1] Indicates a higher degree of risk of default.

[2] Indicates the expected risk of default is currently low.