CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Assets
Cash and due from banks	$ 144,290	$ 151,969
Due from banks - interest-bearing	123,146	246,336
Federal funds sold and securities purchased under resale agreements	219,500	17,100
Securities available-for-sale - cost $7,610,489 and $9,057,238 at March 31, 2013 and December 31, 2012, respectively:
Securities pledged as collateral	40,102	48,697
Held in portfolio	7,697,949	9,157,292
Securities held-to-maturity - fair value $1,434,836 and $1,446,599 at March 31, 2013 and December 31, 2012, respectively	1,400,890	1,398,403
Trading securities	53,526	115,059
Loans and leases, excluding covered loans	15,216,906	14,818,295	12,747,902
Less: Allowance for loan and lease losses	282,328	277,888	266,077
Loans and leases, excluding covered loans, net	14,934,578	14,540,407
Covered loans, net of allowance for loan losses	909,563	986,223	1,438,714
Net loans and leases	15,844,141	15,526,630
Premises and equipment, net	152,389	149,433
Deferred tax asset	133,923	124,461
Goodwill	642,622	642,622	486,682
Customer-relationship intangibles, net	46,207	48,139
Affordable housing investments	150,466	154,011
Customers' acceptance liability	1,581	7,859
Other real estate owned ($43,751 and $58,276 covered by FDIC loss share at March 31, 2013 and December 31, 2012, respectively)	63,537	79,303	107,530
FDIC indemnification asset	142,906	150,018
Other assets	576,579	601,160
Total assets	27,433,754	28,618,492	23,644,899
Liabilities
Demand deposits	13,800,017	14,264,797
Interest checking deposits	2,132,392	2,459,972
Money market deposits	5,705,033	5,610,844
Savings deposits	425,935	398,824
Time deposits-under $100,000	232,350	203,422
Time deposits-$100,000 and over	641,859	564,496
Total deposits	22,937,586	23,502,355	20,217,395
Short-term borrowings	806,760	1,423,798	1,423,798
Long-term debt	702,967	706,051
Reserve for off-balance sheet credit commitments	25,205	24,837	24,067
Acceptances outstanding	1,581	7,859
Other liabilities	361,653	407,162
Total liabilities	24,835,752	26,072,062
Redeemable noncontrolling interest	41,113	41,112
Commitments and contingencies
Shareholders' equity
Preferred stock, par value $1.00 per share; 5,000,000 shares authorized; 175,000 shares issued at March 31, 2013 and December 31, 2012	169,920	169,920
Common stock, par value $1.00 per share; 75,000,000 shares authorized; 54,133,065 and 53,885,886 shares issued at March 31, 2013 and December 31, 2012, respectively	54,133	53,886
Additional paid-in capital	496,013	490,339
Accumulated other comprehensive income	74,222	86,582
Retained earnings	1,788,041	1,738,957
Treasury shares, at cost - 495,447 and 669,454 shares at March 31, 2013 and December 31, 2012, respectively	(25,440)	(34,366)
Total common shareholders' equity	2,386,969	2,335,398
Total shareholders' equity	2,556,889	2,505,318	2,199,565
Total liabilities and shareholders' equity	$ 27,433,754	$ 28,618,492