Fair Value, Transfers Between Fair Value Levels (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Total	$ 0	$ 0	$ 0	$ 0
Trading Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Total	0	0	0	0
Available for sale Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Total	0	0	0	0
Mortgages held for sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Total	0	0	0	0
Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Total	0	0	0	0
Net derivative assets and liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Total	0	0	0	0
Short sale liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Total	0	0	0	0
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	0	(6)	17	(6)
Transfer Out	(1)	0	(247)	0
Level 1 [Member] | Trading Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	0	23	0	23
Transfer Out	(1)	0	(247)	0
Level 1 [Member] | Available for sale Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	0	0	17	0
Transfer Out	0	0	0	0
Level 1 [Member] | Mortgages held for sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	0	0	0	0
Transfer Out	0	0	0	0
Level 1 [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	0	0	0	0
Transfer Out	0	0	0	0
Level 1 [Member] | Net derivative assets and liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	0	0	0	0
Transfer Out	0	0	0	0
Level 1 [Member] | Short sale liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	0	(29)	0	(29)
Transfer Out	0	0	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	64	5,586	11,667	9,795
Transfer Out	(136)	(5,988)	(357)	(6,222)
Level 2 [Member] | Trading Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	15	6	483	16
Transfer Out	(14)	(23)	(40)	(37)
Level 2 [Member] | Available for sale Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	12	5,417	10,853	9,453
Transfer Out	(77)	(16)	(94)	(73)
Level 2 [Member] | Mortgages held for sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	177	79	316	229
Transfer Out	(77)	(127)	(255)	(298)
Level 2 [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	48	0	154	0
Transfer Out	0	(5,851)	0	(5,851)
Level 2 [Member] | Net derivative assets and liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	(188)	84	(139)	97
Transfer Out	32	0	32	8
Level 2 [Member] | Short sale liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	0	0	0	0
Transfer Out	0	29	0	29
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	137	5,994	341	6,228
Transfer Out	(64)	(5,586)	(11,421)	(9,795)
Level 3 [Member] | Trading Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	15	0	41	14
Transfer Out	(15)	(6)	(237)	(16)
Level 3 [Member] | Available for sale Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	77	16	77	73
Transfer Out	(12)	(5,417)	(10,853)	(9,453)
Level 3 [Member] | Mortgages held for sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	77	127	255	298
Transfer Out	(177)	(79)	(316)	(229)
Level 3 [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	0	5,851	0	5,851
Transfer Out	(48)	0	(154)	0
Level 3 [Member] | Net derivative assets and liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	(32)	0	(32)	(8)
Transfer Out	188	(84)	139	(97)
Level 3 [Member] | Short sale liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis Transfers Between Fair Value Levels [Line Items]
Transfer In	0	0	0	0
Transfer Out	$ 0	$ 0	$ 0	$ 0