Fair Value Measurements (Estimated Fair Values Of Financial Instruments Not Recorded At Fair Value In Their Entirety On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Cash and due from banks	$ 1,226		$ 1,140
Interest-bearing deposits with banks	2,668		5,311
Total loans, net of allowance for loan losses	47,291		44,872
Demand deposits (noninterest-bearing)	24,774		23,875
Customer certificates of deposit	4,962		5,063
Total deposits	54,170		53,292
Short-term borrowings	176		253
Medium- and long-term debt	2,620		3,543
Carrying Amount
Cash and due from banks	1,226		1,140
Interest-bearing deposits with banks	2,668		5,311
Loans held-for-sale	6		4
Total loans, net of allowance for loan losses	47,291	[1]	44,872	[1]
Customers' liability on acceptances outstanding	10		11
Nonmarketable equity securities	12	[2]	12	[2]
Restricted equity investments	92		133
Demand deposits (noninterest-bearing)	24,774		23,875
Interest-bearing deposits	24,434		24,354
Customer certificates of deposit	4,962		5,063
Total deposits	54,170		53,292
Short-term borrowings	176		253
Acceptances outstanding	10		11
Medium- and long-term debt	2,620		3,543
Credit-related financial instruments	(94)		(88)
Estimated Fair Value
Cash and due from banks	1,226		1,140
Interest-bearing deposits with banks	2,668		5,311
Loans held-for-sale	6		4
Total loans, net of allowance for loan losses	47,236	[1]	44,801	[1]
Customers' liability on acceptances outstanding	10		11
Nonmarketable equity securities	19	[2]	19	[2]
Restricted equity investments	92		133
Demand deposits (noninterest-bearing)	24,774		23,875
Interest-bearing deposits	24,434		24,354
Customer certificates of deposit	4,955		5,055
Total deposits	54,163		53,284
Short-term borrowings	176		253
Acceptances outstanding	10		11
Medium- and long-term debt	2,593		3,540
Credit-related financial instruments	(94)		(88)
Level 1 | Estimated Fair Value
Cash and due from banks	1,226		1,140
Interest-bearing deposits with banks	2,668		5,311
Loans held-for-sale	0		0
Total loans, net of allowance for loan losses	0		0
Customers' liability on acceptances outstanding	10		11
Nonmarketable equity securities	0		0
Restricted equity investments	92		133
Demand deposits (noninterest-bearing)	0		0
Interest-bearing deposits	0		0
Customer certificates of deposit	0		0
Total deposits	0		0
Short-term borrowings	176		253
Acceptances outstanding	10		11
Medium- and long-term debt	0		0
Credit-related financial instruments	0		0
Level 2 | Estimated Fair Value
Cash and due from banks	0		0
Interest-bearing deposits with banks	0		0
Loans held-for-sale	6		4
Total loans, net of allowance for loan losses	0		0
Customers' liability on acceptances outstanding	0		0
Nonmarketable equity securities	0		0
Restricted equity investments	0		0
Demand deposits (noninterest-bearing)	24,774		23,875
Interest-bearing deposits	24,434		24,354
Customer certificates of deposit	4,955		5,055
Total deposits	54,163		53,284
Short-term borrowings	0		0
Acceptances outstanding	0		0
Medium- and long-term debt	2,593		3,540
Credit-related financial instruments	0		0
Level 3 | Estimated Fair Value
Cash and due from banks	0		0
Interest-bearing deposits with banks	0		0
Loans held-for-sale	0		0
Total loans, net of allowance for loan losses	47,236	[1]	44,801	[1]
Customers' liability on acceptances outstanding	0		0
Nonmarketable equity securities	19	[2]	19	[2]
Restricted equity investments	0		0
Demand deposits (noninterest-bearing)	0		0
Interest-bearing deposits	0		0
Customer certificates of deposit	0		0
Total deposits	0		0
Short-term borrowings	0		0
Acceptances outstanding	0		0
Medium- and long-term debt	0		0
Credit-related financial instruments	(94)		(88)
Nonrecurring | Level 3
Loans	95		128
Nonmarketable equity securities	$ 1		$ 2

[1] Included $95 million and $128 million of impaired loans recorded at fair value on a nonrecurring basis at June 30, 2014 and December 31, 2013, respectively.

[2] Included $1 million and $2 million of nonmarketable equity securities recorded at fair value on a nonrecurring basis at June 30, 2014 and December 31, 2013, respectively.