CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Assets
Cash and due from banks	$ 425,427	$ 183,227
Due from banks - interest bearing	434,297	552,719
Federal funds sold and securities purchased under resale agreements	205,000	200,000
Securities available-for-sale - cost $5,394,065 and $6,267,691 at March 31, 2014 and December 31, 2013, respectively:
Securities pledged as collateral	14,792	12,376
Held in portfolio	5,371,962	6,228,741
Securities held-to-maturity - fair value $3,165,068 and $2,883,935 at March 31, 2014 and December 31, 2013, respectively	3,202,997	2,957,843
Trading securities	61,608	82,357
Loans and leases, excluding covered loans	17,751,385	17,170,438
Less: Allowance for loan and lease losses	305,790	302,584
Loans and leases, excluding covered loans, net	17,445,595	16,867,854
Covered loans, net of allowance for loan losses	654,855	700,989
Net loans and leases	18,100,450	17,568,843
Premises and equipment, net	199,401	198,398
Deferred tax asset	212,611	217,990
Goodwill	642,622	642,622
Customer-relationship intangibles, net	39,134	40,621
Affordable housing investments	199,389	188,207
Customers' acceptance liability	1,295	10,521
Other real estate owned ($24,855 and $25,481 covered by FDIC loss share at March 31, 2014 and December 31, 2013, respectively)	34,267	38,092
FDIC indemnification asset	84,851	89,227
Other assets	508,149	506,167
Total assets	29,738,252	29,717,951
Liabilities
Demand deposits	15,664,029	16,058,968
Interest checking deposits	2,370,741	2,467,890
Money market deposits	6,610,811	6,022,457
Savings deposits	458,328	441,521
Time deposits-under $100,000	172,024	176,488
Time deposits-$100,000 and over	455,833	512,113
Total deposits	25,731,766	25,679,437
Short-term borrowings	4,107	3,889
Long-term debt	733,537	735,968
Reserve for off-balance sheet credit commitments	34,908	33,944
Acceptances outstanding	1,295	10,521
Other liabilities	391,038	473,438
Total liabilities	26,896,651	26,937,197
Redeemable noncontrolling interest	45,641	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 March 31, 2014 and December 31, 2013	267,616	267,616
Common stock, par value $1.00 per share; 75,000,000 shares authorized; 54,899,058 and 54,667,295 shares issued at March 31, 2014 and December 31, 2013, respectively	54,899	54,667
Additional paid-in capital	549,989	541,210
Accumulated other comprehensive loss	(4,363)	(15,641)
Retained earnings	1,950,356	1,918,163
Treasury shares, at cost - 388,156 and 483,523 shares at March 31, 2014 and December 31, 2013, respectively	(22,537)	(25,029)
Total common shareholders' equity	2,528,344	2,473,370
Total shareholders' equity	2,795,960	2,740,986
Total liabilities and shareholders' equity	$ 29,738,252	$ 29,717,951