CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets
Cash and due from banks	$ 503,647	$ 183,227
Due from banks - interest-bearing	625,183	552,719
Federal funds sold and securities purchased under resale agreements	200,000	200,000
Securities available-for-sale - cost $5,641,894 and $6,267,691 at September 30, 2014 and December 31, 2013, respectively:
Securities pledged as collateral	11,684	12,376
Held in portfolio	5,617,492	6,228,741
Securities held-to-maturity - fair value $3,461,988 and $2,883,935 at September 30, 2014 and December 31, 2013, respectively:
Securities pledged as collateral	528,916
Held in portfolio	2,921,635	2,957,843
Trading securities	125,910	82,357
Loans and leases, excluding covered loans	19,347,988	17,170,438
Less: Allowance for loan and lease losses	312,703	302,584
Loans and leases, excluding covered loans, net	19,035,285	16,867,854
Covered loans, net of allowance for loan losses	543,347	700,989
Net loans and leases	19,578,632	17,568,843
Premises and equipment, net	208,711	198,398
Deferred tax asset	215,951	217,990
Goodwill	635,868	642,622
Customer-relationship intangibles, net	36,255	40,621
Affordable housing investments	203,208	188,207
Customers' acceptance liability	2,137	10,521
Other real estate owned ($14,487 and $25,481 covered by FDIC loss share at September 30, 2014 and December 31, 2013, respectively)	24,602	38,092
FDIC indemnification asset	59,917	89,227
Other assets	515,852	506,167
Total assets	32,015,600	29,717,951
Liabilities
Demand deposits	17,827,649	16,058,968
Interest checking deposits	2,520,761	2,467,890
Money market deposits	6,540,000	6,022,457
Savings deposits	473,150	441,521
Time deposits-under $100,000	162,522	176,488
Time deposits-$100,000 and over	431,898	512,113
Total deposits	27,955,980	25,679,437
Short-term borrowings	4,635	3,889
Long-term debt	631,434	735,968
Reserve for off-balance sheet credit commitments	25,910	33,944
Acceptances outstanding	2,137	10,521
Other liabilities	448,853	473,438
Total liabilities	29,068,949	26,937,197
Redeemable noncontrolling interest	47,222	39,768
Commitments and contingencies
Shareholders' equity
Preferred stock, par value $1.00 per share; 5,000,000 shares authorized; 275,000 shares issued at September 30, 2014 and December 31, 2013	267,616	267,616
Common stock, par value $1.00 per share; 75,000,000 shares authorized; 55,057,737 and 54,667,295 shares issued at September 30, 2014 and December 31, 2013, respectively	55,058	54,667
Additional paid-in capital	565,822	541,210
Accumulated other comprehensive loss	(7,592)	(15,641)
Retained earnings	2,040,868	1,918,163
Treasury shares, at cost - 378,456 and 483,523 shares at September 30, 2014 and December 31, 2013, respectively	(22,343)	(25,029)
Total common shareholders' equity	2,631,813	2,473,370
Total shareholders' equity	2,899,429	2,740,986
Total liabilities and shareholders' equity	$ 32,015,600	$ 29,717,951