CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Assets
Cash and due from banks	$ 215,806	$ 190,606	$ 155,135
Money market and other interest-earning investments	20,887	16,117	61,690
Total cash and cash equivalents	236,693	206,723	216,825
Trading securities-at fair value	3,726	3,566	3,331
Investment securities-available-for-sale, at fair value:
Total investment securities-available-for-sale	2,536,057	2,372,201	2,659,084
Investment securities-held-to-maturity, at amortized cost (fair value $899,007, $780,758 and $419,326, respectively)	852,904	762,734	401,066
Federal Home Loan Bank stock, at cost	42,776	40,584	40,584
Residential loans held for sale, at fair value	11,398	7,705	13,572
Finance leases held for sale			11,553
Loans:
Commercial	1,498,833	1,373,415	1,397,882
Commercial real estate	1,354,700	1,160,890	1,197,997
Residential real estate	1,425,179	1,359,569	1,399,688
Consumer credit, net of unearned income	1,089,008	971,258	892,078
Covered loans, net of discount	171,148	217,832	288,577
Total loans	5,538,868	5,082,964	5,176,222
Allowance for loan losses	(42,494)	(41,741)	(43,890)
Allowance for loan losses-covered loans	(3,658)	(5,404)	(5,428)
Net loans	5,492,716	5,035,819	5,126,904
FDIC indemnification asset	51,431	88,513	100,391
Premises and equipment, net	118,014	108,306	91,445
Accrued interest receivable	54,630	50,205	48,516
Goodwill	408,474	352,729	339,382
Other intangible assets	30,799	25,957	24,993
Company-owned life insurance	299,509	275,121	273,887
Assets held for sale	9,043	9,056	9,275
Other real estate owned and repossessed personal property	6,729	7,562	7,739
Other real estate owned-covered	11,155	13,670	23,131
Other assets	221,879	221,293	249,393
Total assets	10,387,933	9,581,744	9,641,071
Deposits:
Noninterest-bearing demand	2,129,705	2,026,490	1,881,440
Interest-bearing:
NOW	1,912,183	1,775,938	1,652,816
Savings	2,100,173	1,941,652	1,900,148
Money market	428,013	448,848	283,686
Time	984,929	1,017,975	1,122,003
Total deposits	7,555,003	7,210,903	6,840,093
Short-term borrowings	467,578	462,332	530,381
Other borrowings	902,015	556,388	884,347
Accrued expenses and other liabilities	186,006	189,481	219,272
Total liabilities	9,110,602	8,419,104	8,474,093
Shareholders' Equity
Preferred stock, series A, 1,000 shares authorized, no shares issued or outstanding	0	0	0
Common stock, $1 stated value, 150,000 shares authorized, 105,851, 99,859 and 100,881 shares issued and outstanding, respectively	105,851	99,859	100,881
Capital surplus	975,354	900,254	912,391
Retained earnings	229,467	206,993	178,727
Accumulated other comprehensive income (loss), net of tax	(33,341)	(44,466)	(25,021)
Total shareholders' equity	1,277,331	1,162,640	1,166,978
Total liabilities and shareholders' equity	10,387,933	9,581,744	9,641,071
U.S. Treasury [Member]
Investment securities-available-for-sale, at fair value:
Total investment securities-available-for-sale	11,186	13,113	14,366
U.S. Government-Sponsored Entities and Agencies [Member]
Investment securities-available-for-sale, at fair value:
Total investment securities-available-for-sale	623,672	435,588	374,956
Mortgage-Backed Securities [Member]
Investment securities-available-for-sale, at fair value:
Total investment securities-available-for-sale	1,220,293	1,306,670	1,412,869
States and Political Subdivisions [Member]
Investment securities-available-for-sale, at fair value:
Total investment securities-available-for-sale	309,106	268,795	643,887
Other Securities [Member]
Investment securities-available-for-sale, at fair value:
Total investment securities-available-for-sale	$ 371,800	$ 348,035	$ 213,006