Long-Term Debt (Schedule Of Subordinated Notes) (Details) - USD ($) $ in Millions	Dec. 31, 2017	May 15, 2014	Dec. 31, 2016
Subordinated Borrowing [Line Items]
Long-Term Debt, Interest Rate 5.65%	5.65%
Subordinated notes, Balance	$ 247		$ 246
Subordinated Notes Par Amount			250
Long-term Debt, Interest Rate 6.95%	6.95%
Subordinated Notes Interest Rate 5.65 Percent [Member]
Subordinated Borrowing [Line Items]
Subordinated notes, Balance	$ 160
Subordinated Notes Par Amount			162
Subordinated notes, Maturity	Nov. 01, 2023
Interest payments begin		May 15, 2014
Subordinated Notes Interest Rate 6.95 Percent [Member]
Subordinated Borrowing [Line Items]
Subordinated notes, Balance	$ 87
Subordinated Notes Par Amount			$ 88
Subordinated notes, Maturity	Sep. 01, 2028