Consolidated Statements Of Condition (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Assets
Cash and due from banks	$ 286,743	$ 225,136	$ 330,262
Federal funds sold and securities purchased under resale agreements	4,129	5,571	12,476
Interest bearing deposits with banks	697,799	998,437	540,964
Available-for-sale securities, at fair value	1,721,030	1,792,078	1,949,697
Trading account securities	7,811	1,206	1,068
Federal Home Loan Bank and Federal Reserve Bank stock	92,948	91,582	78,524
Brokerage customer receivables	25,287	24,221	26,884
Mortgage loans held-for-sale, at fair value	446,355	351,290	215,231
Loans, net of unearned income, excluding covered loans	14,953,059	14,409,398	13,133,160
Covered loans	209,694	226,709	312,478
Total loans	15,162,753	14,636,107	13,445,638
Less: Allowance for loan losses	94,446	91,705	92,275
Less: Allowance for covered loan losses	1,878	2,131	3,447
Net loans	15,066,429	14,542,271	13,349,916
Premises and equipment, net	559,281	555,228	531,763
FDIC indemnification asset	10,224	11,846	60,298
Accrued interest receivable and other assets	537,117	501,882	549,705
Trade date securities receivable	488,063	485,534	182,600
Goodwill	420,197	405,634	373,725
Other intangible assets	18,858	18,811	18,050
Total assets	20,382,271	20,010,727	18,221,163
Deposits:
Non-interest bearing	3,779,609	3,518,685	2,773,922
Interest bearing	13,159,160	12,763,159	12,355,123
Total deposits	16,938,769	16,281,844	15,129,045
Federal Home Loan Bank advances	416,036	733,050	387,672
Other borrowings	187,006	196,465	231,086
Subordinated notes	140,000	140,000	0
Junior subordinated debentures	249,493	249,493	249,493
Trade date securities payable	2,929	3,828	0
Accrued interest payable and other liabilities	316,964	336,225	283,724
Total liabilities	18,251,197	17,940,905	16,281,020
Preferred stock, no par value; 20,000,000 shares authorized:
Series C - $1,000 liquidation value; 126,427 shares issued and outstanding at March 31, 2015, 126,467 shares issued and outstanding at December 31, 2014, and 126,477 shares issued and outstanding at March, 31, 2014	126,427	126,467	126,477
Common stock, no par value; $1.00 stated value; 100,000,000 shares authorized at March 31, 2015, December 31, 2014, and March 31, 2014; 47,474,721 shares issued at March 31, 2015, 46,881,108 shares issued at December 31, 2014, and 46,332,213 shares issued at March 31, 2014	47,475	46,881	46,332
Surplus	1,156,542	1,133,955	1,122,233
Treasury stock, at cost, 85,113 shares at March 31, 2015, 76,053 shares at December 31, 2014, and 73,253 shares at March 31, 2014	(3,948)	(3,549)	(3,380)
Retained earnings	835,669	803,400	705,234
Accumulated other comprehensive loss	(31,091)	(37,332)	(56,753)
Total shareholders' equity	2,131,074	2,069,822	1,940,143
Total liabilities and shareholders' equity	$ 20,382,271	$ 20,010,727	$ 18,221,163