CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
OPERATING ACTIVITIES
Net income			$ 466	$ 399
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses			181	135
Originations of mortgage loans held for sale			(1,135)	(1,182)
Proceeds from sales of mortgage loans held for sale			1,022	1,111
Purchases of commercial loans held for sale			(735)	(632)
Proceeds from sales of commercial loans held for sale			739	594
Amortization of terminated cash flow hedges			16	9
Depreciation, amortization and accretion			245	234
Mortgage servicing rights valuation charge-off (recovery)	$ (1)	$ (6)	4	(7)
Securities impairment	7	2	8	3
Deferred income taxes			94	56
Share-based compensation			11	15
Net gain on sales of:
Debt securities			(13)	(17)
Marketable equity securities available for sale			0	(3)
Premises and equipment			(2)	0
Increase in other assets			(450)	(138)
Increase (decrease) in other liabilities			253	(62)
Net cash provided by operating activities			704	515
INVESTING ACTIVITIES
Purchases of securities available for sale			(2,355)	(4,089)
Proceeds from maturities and paydowns of securities available for sale			1,611	1,804
Proceeds from sales of securities available for sale			375	1,251
Purchases of securities held to maturity			0	(811)
Proceeds from maturities and paydowns of securities held to maturity			290	394
Purchases of other investment securities, at fair value			(114)	0
Proceeds from sales of other investment securities, at fair value			109	0
Purchases of other investment securities, at cost			(62)	(14)
Proceeds from sales of other investment securities, at cost			52	20
Net (increase) decrease in interest-bearing deposits in banks			(371)	184
Net increase in loans and leases			(5,045)	(3,573)
Net increase in bank-owned life insurance			(23)	(16)
Premises and equipment:
Purchases			(22)	(43)
Proceeds from sales			3	15
Capitalization of software			(85)	(92)
Net cash used in investing activities			(5,637)	(4,970)
FINANCING ACTIVITIES
Net increase in deposits			3,718	4,908
Net decrease in federal funds purchased and securities sold under agreements to repurchase			(85)	(492)
Net decrease in other short-term borrowed funds			(1,370)	(251)
Proceeds from issuance of long-term borrowed funds			6,995	0
Repayments of long-term borrowed funds			(3,631)	(6)
Treasury stock purchased			0	(250)
Net proceeds from issuance of preferred stock			0	247
Dividends declared and paid to common stockholders			(117)	(108)
Dividends declared and paid to preferred stockholders			(7)	0
Net cash provided by financing activities			5,503	4,048
Increase (decrease) in cash and cash equivalents			570	(407)
Cash and cash equivalents at beginning of period			3,085	3,276	$ 3,276
Cash and cash equivalents at end of period	$ 3,655	$ 2,869	$ 3,655	$ 2,869	$ 3,085