Consolidated Statements Of Condition (USD $)	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Assets
Cash and due from banks	$ 186,752,000	$ 148,012,000	$ 147,270,000
Federal funds sold and securities purchased under resale agreements	26,062,000	21,692,000	13,452,000
Interest-bearing deposits with other banks (no balance restricted for securitization investors at September 30, 2012, and a balance restricted for securitization investors of $272,592 at December 31, 2011, and $37,165 at September 30, 2011)	934,430,000	749,287,000	1,101,353,000
Available-for-sale securities, at fair value	1,256,768,000	1,291,797,000	1,267,682,000
Trading account securities	635,000	2,490,000	297,000
Federal Home Loan Bank and Federal Reserve Bank stock	80,687,000	100,434,000	99,749,000
Brokerage customer receivables	30,633,000	27,925,000	27,935,000
Mortgage loans held-for-sale, at fair value	548,300,000	306,838,000	204,081,000
Mortgage loans held-for-sale, at lower of cost or market	21,685,000	13,686,000	8,955,000
Loans, net of unearned income, excluding covered loans	11,489,900,000	10,521,377,000	10,272,711,000
Covered loans	657,525,000	651,368,000	680,075,000
Total loans	12,147,425,000	11,172,745,000	10,952,786,000
Less: Allowance for loan losses	112,287,000	110,381,000	118,649,000
Loans and Leases Receivable, Allowance, Covered	21,926,000	12,977,000	12,496,000
Net loans (no balance restricted for securitization investors at September 30, 2012, and a balance restricted for securitization investors of $411,532 at December 31, 2011, and $643,466 at September 30, 2011)	12,013,212,000	11,049,387,000	10,821,641,000
Premises and equipment, net	461,905,000	431,512,000	412,478,000
FDIC Indemnification Asset	238,305,000	344,251,000	379,306,000
Accrued interest receivable and other assets	557,884,000	444,912,000	468,711,000
Trade date securities receivable	307,295,000	634,047,000	637,112,000
Goodwill	331,634,000	305,468,000	302,369,000
Other intangible assets	22,405,000	22,070,000	22,413,000
Total assets	17,018,592,000	15,893,808,000	15,914,804,000
Liabilities and Shareholders’ Equity
Non-interest bearing	2,162,215,000	1,785,433,000	1,631,709,000
Interest bearing	11,685,750,000	10,521,834,000	10,674,299,000
Total deposits	13,847,965,000	12,307,267,000	12,306,008,000
Notes payable	2,275,000	52,822,000	3,004,000
Federal Home Loan Bank advances	414,211,000	474,481,000	474,570,000
Other borrowings	377,229,000	443,753,000	448,082,000
Secured borrowings-owed to securitization investors	0	600,000,000	600,000,000
Subordinated notes	15,000,000	35,000,000	40,000,000
Junior subordinated debentures	249,493,000	249,493,000	249,493,000
Trade date securities payable	412,000	47,000	73,874,000
Accrued interest payable and other liabilities	350,707,000	187,412,000	191,586,000
Total liabilities	15,257,292,000	14,350,275,000	14,386,617,000
Preferred stock, no par value; 20,000,000 shares authorized:
Common stock, no par value; $1.00 stated value; 100,000,000 shares authorized; 36,647,154 shares issued at September 30, 2012, 35,981,950 shares issued at December 31, 2011, and 35,926,137 shares issued at September 30, 2011	36,647,000	35,982,000	35,926,000
Surplus	1,018,417,000	1,001,316,000	997,854,000
Treasury stock, at cost, 239,373 shares at September 30, 2012, 3,601 shares at December 31, 2011, and 2,071 shares at September 30, 2011	(7,490,000)	(112,000)	(68,000)
Retained earnings	527,550,000	459,457,000	441,268,000
Accumulated other comprehensive income (loss)	9,805,000	(2,878,000)	3,471,000
Total shareholders' equity	1,761,300,000	1,543,533,000	1,528,187,000
Total liabilities and shareholders' equity	17,018,592,000	15,893,808,000	15,914,804,000
Series A Preferred Stock [Member]
Preferred stock, no par value; 20,000,000 shares authorized:
Preferred stock, value	49,871,000	49,768,000	49,736,000
Series C Preferred Stock [Member]
Preferred stock, no par value; 20,000,000 shares authorized:
Preferred stock, value	$ 126,500,000