CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Assets
Cash and due from banks	$ 433,629	$ 336,470
Due from banks - interest-bearing	704,258	119,981
Federal funds sold and securities purchased under resale agreements	200,000	200,000
Securities available-for-sale - cost $4,943,133 and $5,894,509 at June 30, 2015 and December 31, 2014, respectively
Securities pledged as collateral	10,964	14,654
Held in portfolio	4,929,879	5,868,329
Securities held-to-maturity - fair value $3,460,942 and $3,484,647 at June 30, 2015 and December 31, 2014, respectively
Securities pledged as collateral	518,952	521,262
Held in portfolio	2,903,227	2,905,769
Trading securities	110,136	173,188
Loans and leases, excluding covered loans	21,929,328	20,337,206
Less: Allowance for loan and lease losses	316,922	310,149
Loans and leases, excluding covered loans, net	21,612,406	20,027,057
Covered loans, net of allowance for loan losses	425,958	502,371
Net loans and leases	22,038,364	20,529,428
Premises and equipment, net	205,507	207,700
Deferred tax asset	237,853	233,811
Goodwill	637,918	635,868
Customer-relationship intangibles, net	32,227	34,831
Affordable housing investments	194,443	186,423
Customers' acceptance liability	3,462	17,664
Other real estate owned ($11,311 and $12,760 covered by FDIC loss share at June 30, 2015 and December 31, 2014, respectively)	17,268	23,496
FDIC indemnification asset	34,799	50,511
Other assets	547,612	537,847
Total assets	33,760,498	32,597,232
Liabilities
Demand deposits	19,648,595	18,030,021
Interest checking deposits	2,462,289	2,736,391
Money market deposits	6,323,160	6,198,798
Savings deposits	483,794	469,931
Time deposits-under $100,000	147,138	155,568
Time deposits-$100,000 and over	416,254	517,394
Total deposits	29,481,230	28,108,103
Short-term borrowings	6,322	322,861
Long-term debt	640,617	638,600
Reserve for off-balance sheet credit commitments	30,024	27,811
Acceptances outstanding	3,462	17,664
Other liabilities	488,940	499,514
Total liabilities	30,650,595	29,614,553
Redeemable noncontrolling interest	$ 37,755	$ 39,978
Commitments and contingencies
Shareholders' Equity
Preferred stock, par value $1.00 per share; 5,000,000 shares authorized; 275,000 shares issued at June 30, 2015 and December 31, 2014	$ 267,616	$ 267,616
Common stock, par value $1.00 per share; 75,000,000 shares authorized; 55,664,127 and 55,162,455 shares issued at June 30, 2015 and December 31, 2014, respectively	55,664	55,162
Additional paid-in capital	615,371	578,046
Accumulated other comprehensive loss	(1,760)	(7,074)
Retained earnings	2,153,871	2,071,230
Treasury shares, at cost - 311,068 and 377,224 shares at June 30, 2015 and December 31, 2014, respectively	(18,614)	(22,279)
Total common shareholders' equity	2,804,532	2,675,085
Total shareholders' equity	3,072,148	2,942,701
Total liabilities and shareholders' equity	$ 33,760,498	$ 32,597,232