Statements of Cash Flow - Parent Company Only (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Net Income (Loss) Attributable to Parent	$ 1,344		$ 1,958		$ 647
Adjustments to reconcile net income/(loss) to net cash used in by operating activities:
Deferred Income Tax Expense (Benefit)	495		194		83
Net gain on sale of assets	(267)		(1,063)		(390)
Net (increase)/decrease in other assets	235		974		(604)
Cash Flows from Investing Activities:
Proceeds from sales of securities available for sale	2,063		4,300		12,557
Purchases of securities available for sale	(9,215)		(5,814)		(18,872)
Net cash (used in)/provided by investing activities	(8,941)		4,743		(10,242)
Cash Flows from Financing Activities:
Proceeds from Issuance of Preferred Stock and Preference Stock	0		438		103
Payments for Repurchase of Warrants	0		0		(11)
Net cash provided by/(used in) financing activities	1,739		(3,005)		4,834
Supplemental Disclosures:
Income Taxes Paid	168		607		68
Accretion of discount for preferred stock issued to the U.S. Treasury	0		0		80
Depreciation, Amortization and Accretion, Net	708		757		760
Stock Option Compensation And Amortization Of Restricted Stock Compensation	34		35		44
Gains (Losses) on Extinguishment of Debt	0		16		(3)
Gain (Loss) on Sale of Securities, Net	(2)	[1]	(1,974)	[1]	(117)	[1]
Increase (Decrease) in Other Operating Liabilities	(827)		(1,026)		18
Net Cash Provided by (Used in) Operating Activities	4,208		2,010		4,539
Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities	5,522		7,371		5,557
Proceeds from maturities, calls, and paydowns of trading securities	2		3		139
Proceeds from Sale of Other Investments	8		0		102
Proceeds from Issuance of Long-term Debt	1,564		4,000		1,749
Repayments of Long-term Debt	(155)		(5,772)		(4,571)
Proceeds from the issuance of common stock	0		0		1,017
Payments for Repurchase of Preferred Stock and Preference Stock	0		0		(4,850)
Payments for Repurchase of Common Stock	(150)		0		0
Net (decrease)/increase in cash and cash equivalents	(2,994)		3,748		(869)
Cash and Cash Equivalents, at Carrying Value	5,263		8,257		4,509
Interest Paid	533		774		1,138
Parent Company [Member]
Net Income (Loss) Attributable to Parent	1,344		1,958		647
Adjustments to reconcile net income/(loss) to net cash used in by operating activities:
Deferred Income Tax Expense (Benefit)	74		18		(56)
Contributions to retirement plans	(8)		(26)		(8)
Net (increase)/decrease in other assets	50		(190)		(192)
Cash Flows from Investing Activities:
Proceeds from sales of securities available for sale	57		47		6,700
Purchases of securities available for sale	(25)		(68)		(2,374)
Capital contributions to subsidiaries	0		(150)		(250)
Net cash (used in)/provided by investing activities	1,518		836		1,164
Cash Flows from Financing Activities:
Proceeds from Issuance of Preferred Stock and Preference Stock	0		438		103
Payments for Repurchase of Warrants	0		0		(11)
Net cash provided by/(used in) financing activities	(306)		(1,778)		(2,142)
Supplemental Disclosures:
Income taxes (paid to)/received from subsidiaries	(195)		621		(2)
Income Taxes Paid	55		(605)		(66)
Income taxes received/(paid) by Parent Company	(140)		16		(68)
Accretion of discount for preferred stock issued to the U.S. Treasury	0		0		80
Equity in Undistributed Earnings of Subsidiaries	(125)		(2,110)		(745)
Depreciation, Amortization and Accretion, Net	5		10		17
Excess Tax Benefit from Share-based Compensation, Operating Activities	(4)		(11)		0
Stock Option Compensation And Amortization Of Restricted Stock Compensation	34		35		44
Gains (Losses) on Extinguishment of Debt	0		15		(3)
Gain (Loss) on Sale of Securities, Net	(2)		(6)		(92)
Increase (Decrease) in Other Operating Liabilities	(327)		369		130
Net Cash Provided by (Used in) Operating Activities	1,041		62		(258)
Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities	55		65		61
Proceeds from maturities, calls, and paydowns of trading securities	1		2		137
Proceeds from Sale of Other Investments	8		0		75
Payments for (Proceeds from) Loans Receivable	1,422		940		(3,185)
Proceeds from (Repayments of) Short-term Debt	(827)		935		463
Proceeds from Issuance of Long-term Debt	888		15		1,749
Repayments of Long-term Debt	(9)		(3,073)		(482)
Proceeds from the issuance of common stock	0		0		1,017
Payments for Repurchase of Preferred Stock and Preference Stock	0		0		(4,850)
Payments for Repurchase of Common Stock	(150)		0		0
Proceeds from Stock Options Exercised	17		26		0
Payments of Dividends	(225)		(119)		(131)
Net (decrease)/increase in cash and cash equivalents	2,253		(880)		(1,236)
Cash and Cash Equivalents, at Carrying Value	3,014		761		1,641
Interest Paid	$ 112		$ 189		$ 246

[1] Total OTTI was $0, $1 million, and $2 million for the years ended December 31, 2013, 2012, and 2011, respectively. Of total OTTI, losses of $1 million, $7 million, and $6 million were recognized in earnings, and gains of $1 million, $6 million, and $4 million were recognized as non-credit-related OTTI in OCI for the years ended December 31, 2013, 2012, and 2011, respectively.