Fair Value Disclosures (Summary Of Trading Assets And Trading Liabilities) (Details)	Mar. 31, 2014	Dec. 31, 2013
Trading Assets and Trading Liabilities Measured Using Different Valuation Basis [Line Items]
Trading assets	100.00%	100.00%
Trading liabilities	100.00%	100.00%
Exchange Closing Prices [Member]
Trading Assets and Trading Liabilities Measured Using Different Valuation Basis [Line Items]
Trading assets	12.00%	12.00%
Trading liabilities	16.00%	25.00%
Recently Observed Transaction Prices [Member]
Trading Assets and Trading Liabilities Measured Using Different Valuation Basis [Line Items]
Trading assets	6.00%	5.00%
Trading liabilities	5.00%	4.00%
External Pricing Services [Member]
Trading Assets and Trading Liabilities Measured Using Different Valuation Basis [Line Items]
Trading assets	68.00%	68.00%
Trading liabilities	74.00%	66.00%
Broker Quotes [Member]
Trading Assets and Trading Liabilities Measured Using Different Valuation Basis [Line Items]
Trading assets	3.00%	3.00%
Trading liabilities	3.00%	3.00%
Valuation Techniques [Member]
Trading Assets and Trading Liabilities Measured Using Different Valuation Basis [Line Items]
Trading assets	11.00%	12.00%
Trading liabilities	2.00%	2.00%