LOANS AND LEASES, Aging (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	$ 68,877	$ 71,328
60-89 Days Past Due	22,770	26,908
90 Plus Days Past Due	95,803	150,643
Total Past Due	187,450	248,879
Current	8,868,455	9,084,228
Total Outstanding	9,055,905	9,333,107
90 Plus Days Past Due still Accruing	7,354	8,500	9,910
Commercial and industrial segment [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	8,595	13,037
60-89 Days Past Due	4,103	848
90 Plus Days Past Due	4,084	12,000
Total Past Due	16,782	25,885
Current	1,486,609	1,465,298
Total Outstanding	1,503,391	1,491,183
90 Plus Days Past Due still Accruing	1,846	675
Real estate segment [Member] | Consumer mortgages [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	17,129	16,937
60-89 Days Past Due	6,629	4,481
90 Plus Days Past Due	18,284	20,640
Total Past Due	42,042	42,058
Current	1,924,082	1,909,505
Total Outstanding	1,966,124	1,951,563
90 Plus Days Past Due still Accruing	4,136	6,521
Real estate segment [Member] | Home equity [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	1,902	1,258
60-89 Days Past Due	427	800
90 Plus Days Past Due	1,086	755
Total Past Due	3,415	2,813
Current	519,615	540,459
Total Outstanding	523,030	543,272
90 Plus Days Past Due still Accruing	134	173
Real estate segment [Member] | Agricultural [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	3,058	1,140
60-89 Days Past Due	983	3,450
90 Plus Days Past Due	2,302	3,527
Total Past Due	6,343	8,117
Current	243,372	244,175
Total Outstanding	249,715	252,292
90 Plus Days Past Due still Accruing	131	123
Real estate segment [Member] | Commercial and industrial-owner occupied [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	7,893	9,260
60-89 Days Past Due	1,331	1,290
90 Plus Days Past Due	9,144	7,323
Total Past Due	18,368	17,873
Current	1,311,276	1,313,600
Total Outstanding	1,329,644	1,331,473
90 Plus Days Past Due still Accruing	42	20
Real estate segment [Member] | Construction, acquisition and development [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	13,935	22,436
60-89 Days Past Due	5,151	9,837
90 Plus Days Past Due	55,383	94,264
Total Past Due	74,469	126,537
Current	902,225	1,048,206
Total Outstanding	976,694	1,174,743
90 Plus Days Past Due still Accruing	290	197
Real estate segment [Member] | Commercial [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	13,745	4,409
60-89 Days Past Due	2,848	4,712
90 Plus Days Past Due	4,208	10,507
Total Past Due	20,801	19,628
Current	1,751,202	1,797,323
Total Outstanding	1,772,003	1,816,951
90 Plus Days Past Due still Accruing	106	0
Credit cards segment [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	629	793
60-89 Days Past Due	398	373
90 Plus Days Past Due	507	780
Total Past Due	1,534	1,946
Current	101,698	104,399
Total Outstanding	103,232	106,345
90 Plus Days Past Due still Accruing	257	330
All other receivables [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	1,991	2,058
60-89 Days Past Due	900	1,117
90 Plus Days Past Due	805	847
Total Past Due	3,696	4,022
Current	628,376	661,263
Total Outstanding	632,072	665,285
90 Plus Days Past Due still Accruing	$ 412	$ 461