Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES
Net income for the period	$ 109,597	$ 108,718	$ 290,464	$ 233,919
Adjustments to reconcile net income to net cash provided by operating activities:
Net impairment losses on investment securities	2,736	13,334	20,253	21,597
Provision for credit losses	375	12,351	28,056	62,237
Depreciation and amortization	47,810	52,288	167,119	247,884
Deferred income tax expense (benefit)	6,458	41,563	25,513	129,266
Net write-down of and losses from sales of other real estate owned	309	15,550	13,650	49,663
Net increase (decrease) in trading securities	6,576	1,370	26,310	(1,115)
Net decrease in loans held for sale	(77,225)	21,237	(5,848)	90,749
Change in other liabilities	(10,692)	33,697	(41,222)	26,801
Change in other assets	21,314	(84,465)	110,137	(24,977)
Other, net	(13,692)	261	(32,064)	(4,673)
Net cash provided by operating activities	93,566	215,904	602,368	831,351
CASH FLOWS FROM INVESTING ACTIVITIES
Net increase in money market investments	490,947	(235,048)	(356,703)	(576,859)
Proceeds from maturities and paydowns of investment securities held-to-maturity	37,016	30,080	91,701	72,111
Purchases of investment securities held-to-maturity	(4,450)	(9,667)	(38,188)	(36,476)
Proceeds from sales, maturities, and paydowns of investment securities available-for-sale	187,180	507,676	863,354	1,087,345
Purchases of investment securities available-for-sale	(73,636)	(523,772)	(667,566)	(1,042,235)
Proceeds from sales of loans and leases	24,665	8,836	64,452	15,026
Net loan and lease collections (originations)	(397,845)	(107,759)	(379,615)	(633,630)
Net decrease in other noninterest-bearing investments	2,549	2,372	14,723	12,690
Net purchases of premises and equipment	(15,145)	(22,749)	(47,962)	(62,229)
Proceeds from sales of other real estate owned	59,876	89,245	157,760	276,122
Net cash received (paid for) branch sales	2,667	0	(19,901)	0
Net cash provided by (used in) investing activities	313,824	(260,786)	(317,945)	(888,135)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase (decrease) in deposits	612,290	171,934	926,287	428,209
Net change in short-term funds borrowed	(392,564)	(34,498)	(243,356)	(145,081)
Proceeds from issuance of long-term debt	49,082	23,527	648,468	53,777
Repayments of long-term debt	(7,604)	(8,191)	(262,783)	(8,522)
Cash paid for preferred stock redemption	(700,000)	0	(1,542,500)	0
Proceeds from issuance of common stock and preferred stock	513	237	142,516	25,644
Dividends paid on common and preferred stock	(32,770)	(40,297)	(109,088)	(115,201)
Other, net	(92)	(90)	(7,399)	(3,400)
Net cash provided by (used in) financing activities	(471,145)	112,622	(447,855)	235,426
Net increase (decrease) in cash and due from banks	(63,755)	67,740	(163,432)	178,642
Cash and due from banks at beginning of period	1,124,673	1,035,028	1,224,350	924,126
Cash and due from banks at end of period	1,060,918	1,102,768	1,060,918	1,102,768
Cash paid for interest	65,384	71,220	172,712	213,540
Net cash paid for income taxes	$ 67,772	$ 0	$ 127,456	$ 428