Investment Securities (Gross Unrealized Loss and Fair Value of Securities Available for Sale) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss position less than 12 months - unrealized loss	$ (22)	$ (306)
Unrealized loss position less than 12 months - fair value	4,457	14,717
Unrealized loss position 12 months or more - unrealized loss	(214)	(213)
Unrealized loss position 12 months or more - fair value	5,654	2,526
Total unrealized loss	(236)	(519)
Total fair value	10,111	17,243
US Treasury and Government Agencies Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss position less than 12 months - unrealized loss	(3)	(7)
Unrealized loss position less than 12 months - fair value	1,878	1,066
Total unrealized loss	(3)	(7)
Total fair value	1,878	1,066
Residential Mortgage-backed Securities [Member] | Mortgage-backed Securities Agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss position less than 12 months - unrealized loss	(10)	(210)
Unrealized loss position less than 12 months - fair value	959	7,950
Unrealized loss position 12 months or more - unrealized loss	(70)	(12)
Unrealized loss position 12 months or more - fair value	2,591	293
Total unrealized loss	(80)	(222)
Total fair value	3,550	8,243
Residential Mortgage-backed Securities [Member] | Mortgage-backed Securities Non-agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss position less than 12 months - unrealized loss	(3)	(18)
Unrealized loss position less than 12 months - fair value	237	855
Unrealized loss position 12 months or more - unrealized loss	(99)	(142)
Unrealized loss position 12 months or more - fair value	1,673	1,719
Total unrealized loss	(102)	(160)
Total fair value	1,910	2,574
Commercial Mortgage Backed Securities [Member] | Mortgage-backed Securities Agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss position less than 12 months - unrealized loss		(1)
Unrealized loss position less than 12 months - fair value	60	23
Unrealized loss position 12 months or more - fair value	19
Total unrealized loss		(1)
Total fair value	79	23
Commercial Mortgage Backed Securities [Member] | Mortgage-backed Securities Non-agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss position less than 12 months - unrealized loss	(1)	(18)
Unrealized loss position less than 12 months - fair value	336	1,315
Unrealized loss position 12 months or more - unrealized loss	(3)
Unrealized loss position 12 months or more - fair value	214	14
Total unrealized loss	(4)	(18)
Total fair value	550	1,329
Asset backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss position less than 12 months - unrealized loss	(3)	(11)
Unrealized loss position less than 12 months - fair value	892	1,752
Unrealized loss position 12 months or more - unrealized loss	(27)	(37)
Unrealized loss position 12 months or more - fair value	593	202
Total unrealized loss	(30)	(48)
Total fair value	1,485	1,954
State and Municipal [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss position less than 12 months - unrealized loss		(23)
Unrealized loss position less than 12 months - fair value	10	897
Unrealized loss position 12 months or more - unrealized loss	(10)	(21)
Unrealized loss position 12 months or more - fair value	333	286
Total unrealized loss	(10)	(44)
Total fair value	343	1,183
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss position less than 12 months - unrealized loss	(2)	(17)
Unrealized loss position less than 12 months - fair value	85	844
Unrealized loss position 12 months or more - unrealized loss	(4)	(1)
Unrealized loss position 12 months or more - fair value	216	12
Total unrealized loss	(6)	(18)
Total fair value	301	856
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss position less than 12 months - unrealized loss	(22)	(305)
Unrealized loss position less than 12 months - fair value	4,457	14,702
Unrealized loss position 12 months or more - unrealized loss	(213)	(213)
Unrealized loss position 12 months or more - fair value	5,639	2,526
Total unrealized loss	(235)	(518)
Total fair value	10,096	17,228
Corporate Stocks And Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss position less than 12 months - unrealized loss		(1)
Unrealized loss position less than 12 months - fair value		15
Unrealized loss position 12 months or more - unrealized loss	(1)
Unrealized loss position 12 months or more - fair value	15
Total unrealized loss	(1)	(1)
Total fair value	$ 15	$ 15