Consolidated Statements Of Cash Flows (USD $) In Millions	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
OPERATING ACTIVITIES
Net income	$ 297	$ 181
Income from discontinued operations, net of tax		17
Income from continuing operations, net of tax	297	164
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	134	423
Provision for credit losses on lending-related commitments	(8)	1
Provision (benefit) for deferred income taxes	52	(4)
Depreciation and software amortization	90	94
Share-based compensation expense	29	24
Net amortization of securities	27	14
Accretion of loan purchase discount	(27)
Net securities gains	(18)	(3)
Excess tax benefits from share-based compensation arrangements	(1)	(1)
Net decrease in trading securities	14	14
Net (increase) decrease in loans held-for-sale	(10)	9
Net decrease in accrued income receivable	2	12
Net decrease in accrued expenses	1	16
Other, net	174	215
Discontinued operations, net		17
Net cash provided by operating activities	756	995
INVESTING ACTIVITIES
Proceeds from maturities and redemptions of investment securities available-for-sale	1,757	1,397
Proceeds from sales of investment securities available-for-sale	773	149
Purchases of investment securities available-for-sale	(3,007)	(775)
Proceeds from sales of indirect private equity and venture capital funds	33
Net decrease in loans	819	1,350
Net increase in fixed assets	(92)	(65)
Net decrease (increase) in customers' liability on acceptances outstanding	1	(2)
Cash and cash equivalents acquired in acquisition of Sterling Bancshares, Inc.	721
Sales of Federal Home Loan Bank stock	33	123
Net cash provided by investing activities	1,038	2,177
FINANCING ACTIVITIES
Net increase in deposits	2,898	917
Net increase (decrease) in short-term borrowings	12	(283)
Net increase (decrease) in acceptances outstanding	(1)	2
Proceeds from issuance of medium- and long-term debt		298
Repayments of medium- and long-term debt	(1,464)	(2,101)
Redemption of medium- and long-term debt		(2,165)
Proceeds from issuance of common stock		849
Redemption of preferred stock		(2,250)
Proceeds from issuance of common stock under employee stock plans	3	4
Excess tax benefits from share-based compensation arrangements	1	1
Purchase of common stock for treasury	(75)	(4)
Dividends paid on common stock	(53)	(25)
Dividends paid on preferred stock		(38)
Net cash provided by (used in) financing activities	1,321	(4,795)
Net increase (decrease) in cash and cash equivalents	3,115	(1,623)
Cash and cash equivalents at beginning of period	2,083	5,617
Cash and cash equivalents at end of period	5,198	3,994
Interest paid	113	180
Income taxes, tax deposits and tax-related interest paid	48	48
Noncash investing and financing activities:
Loans transferred to other real estate	41	83
Net noncash assets acquired in stock acquisition of Sterling Bancshares, Inc.	$ 82