Financial Derivatives (Internal Credit Ratings of Risk Participation Agreements Sold) (Details) (Risk Participation Agreements Sold [Member])	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Risk Level, High [Member]
Internal Credit Ratings of Risk Participation Agreements Sold	2%	1%
Risk Level, Low [Member]
Internal Credit Ratings of Risk Participation Agreements Sold	98%	99%