LOANS AND LEASES, Grade (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	$ 8,581,538	$ 8,636,989
Pass [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	7,778,236	7,806,414
Special Mention [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	204,585	181,808
Substandard [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	454,299	485,217
Doubtful [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	6,254	6,538
Loss [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	373	284
Impaired [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	137,791	156,728
Commercial and industrial segment [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	1,480,916	1,476,611
Commercial and industrial segment [Member] | Pass [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	1,430,760	1,426,498
Commercial and industrial segment [Member] | Special Mention [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	14,297	14,663
Commercial and industrial segment [Member] | Substandard [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	31,749	29,876
Commercial and industrial segment [Member] | Doubtful [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	546	729
Commercial and industrial segment [Member] | Loss [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	105	0
Commercial and industrial segment [Member] | Impaired [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	3,459	4,845
Real estate segment [Member] | Consumer mortgages [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	1,871,312	1,873,875
Real estate segment [Member] | Home equity [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	482,398	486,074
Real estate segment [Member] | Agricultural [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	249,467	256,196
Real estate segment [Member] | Commercial and industrial-owner occupied [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	1,334,974	1,333,103
Real estate segment [Member] | Construction, acquisition and development [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	728,092	735,808
Real estate segment [Member] | Commercial real estate [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	1,739,533	1,748,881
Real estate segment [Member] | Pass [Member] | Consumer mortgages [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	1,691,053	1,691,682
Real estate segment [Member] | Pass [Member] | Home equity [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	458,264	461,151
Real estate segment [Member] | Pass [Member] | Agricultural [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	218,018	227,138
Real estate segment [Member] | Pass [Member] | Commercial and industrial-owner occupied [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	1,219,024	1,202,111
Real estate segment [Member] | Pass [Member] | Construction, acquisition and development [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	577,477	567,881
Real estate segment [Member] | Pass [Member] | Commercial real estate [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	1,508,593	1,524,262
Real estate segment [Member] | Special Mention [Member] | Consumer mortgages [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	33,895	32,840
Real estate segment [Member] | Special Mention [Member] | Home equity [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	5,269	4,791
Real estate segment [Member] | Special Mention [Member] | Agricultural [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	9,508	5,729
Real estate segment [Member] | Special Mention [Member] | Commercial and industrial-owner occupied [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	33,370	31,087
Real estate segment [Member] | Special Mention [Member] | Construction, acquisition and development [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	35,525	30,846
Real estate segment [Member] | Special Mention [Member] | Commercial real estate [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	63,186	53,455
Real estate segment [Member] | Substandard [Member] | Consumer mortgages [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	126,589	131,141
Real estate segment [Member] | Substandard [Member] | Home equity [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	15,908	17,619
Real estate segment [Member] | Substandard [Member] | Agricultural [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	17,097	17,947
Real estate segment [Member] | Substandard [Member] | Commercial and industrial-owner occupied [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	68,024	82,816
Real estate segment [Member] | Substandard [Member] | Construction, acquisition and development [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	68,648	75,031
Real estate segment [Member] | Substandard [Member] | Commercial real estate [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	117,806	120,591
Real estate segment [Member] | Doubtful [Member] | Consumer mortgages [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	3,207	2,907
Real estate segment [Member] | Doubtful [Member] | Home equity [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	893	1,057
Real estate segment [Member] | Doubtful [Member] | Agricultural [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	0	0
Real estate segment [Member] | Doubtful [Member] | Commercial and industrial-owner occupied [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	190	369
Real estate segment [Member] | Doubtful [Member] | Construction, acquisition and development [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	626	715
Real estate segment [Member] | Doubtful [Member] | Commercial real estate [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	245	160
Real estate segment [Member] | Loss [Member] | Consumer mortgages [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	88	198
Real estate segment [Member] | Loss [Member] | Home equity [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	27	76
Real estate segment [Member] | Loss [Member] | Agricultural [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	0	0
Real estate segment [Member] | Loss [Member] | Commercial and industrial-owner occupied [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	148	0
Real estate segment [Member] | Loss [Member] | Construction, acquisition and development [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	0	0
Real estate segment [Member] | Loss [Member] | Commercial real estate [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	0	0
Real estate segment [Member] | Impaired [Member] | Consumer mortgages [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	16,480	15,107
Real estate segment [Member] | Impaired [Member] | Home equity [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	2,037	1,380
Real estate segment [Member] | Impaired [Member] | Agricultural [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	4,844	5,382
Real estate segment [Member] | Impaired [Member] | Commercial and industrial-owner occupied [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	14,218	16,720
Real estate segment [Member] | Impaired [Member] | Construction, acquisition and development [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	45,816	61,335
Real estate segment [Member] | Impaired [Member] | Commercial real estate [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	49,703	50,413
Credit cards segment [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	98,803	104,884
Credit cards segment [Member] | Pass [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	98,803	104,884
Credit cards segment [Member] | Special Mention [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	0	0
Credit cards segment [Member] | Substandard [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	0	0
Credit cards segment [Member] | Doubtful [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	0	0
Credit cards segment [Member] | Loss [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	0	0
Credit cards segment [Member] | Impaired [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	0	0
All other [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	596,043	621,557
All other [Member] | Pass [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	576,244	600,807
All other [Member] | Special Mention [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	9,535	8,397
All other [Member] | Substandard [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	8,478	10,196
All other [Member] | Doubtful [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	547	601
All other [Member] | Loss [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	5	10
All other [Member] | Impaired [Member]
Loan and lease portfolio, net of unearned income, by grade [Abstract]
Total	$ 1,234	$ 1,546