Restructuring Charges (Schedule Of Restructuring Charges) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			$ 16
Charged to Costs and Expenses			14	$ 6	$ (1)
Ending Reserve Balance	$ 17	$ 16	17	16
Closed Restructuring Programs
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			13	20	35
Charged to Costs and Expenses			0	2	(1)
Payments and Other			(5)	(9)	(14)
Ending Reserve Balance	8	13	8	13	20
Closed Restructuring Programs | Branch closure charges
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			13	20	33
Charged to Costs and Expenses			0	2	(1)
Payments and Other			(5)	(9)	(12)
Ending Reserve Balance	8	13	8	13	20
Closed Restructuring Programs | Severance costs
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			0	0	2
Charged to Costs and Expenses			0	0	0
Payments and Other			0	0	(2)
Ending Reserve Balance	0	0	0	0	0
2015-2016 Cost Savings Restructuring Program
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			3	0
Charged to Costs and Expenses	6	4	14	4
Payments and Other			(8)	(1)
Ending Reserve Balance	9	3	9	3	0
2015-2016 Cost Savings Restructuring Program | Branch closure charges
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			0	0
Charged to Costs and Expenses			10	0
Payments and Other			(2)	0
Ending Reserve Balance	8	0	8	0	0
2015-2016 Cost Savings Restructuring Program | Severance costs
Restructuring Reserve [Roll Forward]
Beginning Reserve Balance			3	0
Charged to Costs and Expenses			4	4
Payments and Other			(6)	(1)
Ending Reserve Balance	$ 1	$ 3	$ 1	$ 3	$ 0