Fair Value (Schedule Of Realized Gains (Losses) Using Level 3 Inputs) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	$ 15,283		$ 15,283			$ 15,619
Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	107	$ 103	107	$ 103	$ 105	102	$ 102	$ 95
Fair Value, Assets Measured On Recurring Basis, And Gain (Loss) Included In Equity Securities Gains (Losses), Net	1	(1)	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	1	2	5	8
Servicing Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	19	18	19	18	$ 19	18	$ 18	$ 18
Fair Value, Assets Measured On Recurring Basis, And Gain (Loss) Included In Equity Securities Gains (Losses), Net	0	0	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	0	$ 0	0	$ 0
Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	6		6			32
Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	1		1			1
Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	1		1			0
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	8		8			33
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	263		263			153
Fair Value, Inputs, Level 1 [Member] | Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0			0
Fair Value, Inputs, Level 1 [Member] | Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0			0
Fair Value, Inputs, Level 1 [Member] | Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0			0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0			0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	14,893		14,893			15,346
Fair Value, Inputs, Level 2 [Member] | Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	6		6			32
Fair Value, Inputs, Level 2 [Member] | Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0			0
Fair Value, Inputs, Level 2 [Member] | Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	1		1			0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	7		7			32
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	127		127			120
Fair Value, Inputs, Level 3 [Member] | Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0			0
Fair Value, Inputs, Level 3 [Member] | Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	1		1			1
Fair Value, Inputs, Level 3 [Member] | Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0			0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	$ 1		$ 1			$ 1