LOAN AND LEASES (1) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	$ 35,321	$ 37,336
60-89 Days Past Due	12,631	20,207
90 Plus Days Past Due	59,608	78,309
Total Past Due	107,560	135,852
Current	8,624,835	8,734,459
Total Outstanding	8,732,395	8,870,311
90 Plus Days Past Due still Accruing	1,632	3,434	3,980
Commercial and industrial segment [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	5,516	5,571
60-89 Days Past Due	782	4,209
90 Plus Days Past Due	5,697	4,193
Total Past Due	11,995	13,973
Current	1,485,683	1,459,755
Total Outstanding	1,497,678	1,473,728
90 Plus Days Past Due still Accruing	0	12
Real estate segment [Member] | Consumer mortgages [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	12,472	15,740
60-89 Days Past Due	3,849	6,485
90 Plus Days Past Due	15,421	14,569
Total Past Due	31,742	36,794
Current	1,872,678	1,908,396
Total Outstanding	1,904,420	1,945,190
90 Plus Days Past Due still Accruing	1,141	2,974
Real estate segment [Member] | Home equity [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	1,268	1,837
60-89 Days Past Due	547	265
90 Plus Days Past Due	157	594
Total Past Due	1,972	2,696
Current	494,273	511,666
Total Outstanding	496,245	514,362
90 Plus Days Past Due still Accruing	0	0
Real estate segment [Member] | Agricultural [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	1,162	666
60-89 Days Past Due	952	54
90 Plus Days Past Due	4,209	719
Total Past Due	6,323	1,439
Current	245,652	238,048
Total Outstanding	251,975	239,487
90 Plus Days Past Due still Accruing	0	0
Real estate segment [Member] | Commercial and industrial-owner occupied [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	2,888	2,199
60-89 Days Past Due	1,609	844
90 Plus Days Past Due	7,209	12,977
Total Past Due	11,706	16,020
Current	1,277,181	1,285,555
Total Outstanding	1,288,887	1,301,575
90 Plus Days Past Due still Accruing	0	0
Real estate segment [Member] | Construction, acquisition and development [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	7,449	4,826
60-89 Days Past Due	1,012	4,955
90 Plus Days Past Due	17,319	33,584
Total Past Due	25,780	43,365
Current	809,242	864,997
Total Outstanding	835,022	908,362
90 Plus Days Past Due still Accruing	0	0
Real estate segment [Member] | Commercial Real Estate [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	1,549	3,778
60-89 Days Past Due	3,305	2,702
90 Plus Days Past Due	8,592	9,397
Total Past Due	13,446	15,877
Current	1,735,302	1,738,145
Total Outstanding	1,748,748	1,754,022
90 Plus Days Past Due still Accruing	0	0
Credit cards segment [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	420	595
60-89 Days Past Due	286	303
90 Plus Days Past Due	564	697
Total Past Due	1,270	1,595
Current	99,815	104,686
Total Outstanding	101,085	106,281
90 Plus Days Past Due still Accruing	324	299
All other receivables [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	2,597	2,124
60-89 Days Past Due	289	390
90 Plus Days Past Due	440	1,579
Total Past Due	3,326	4,093
Current	605,009	623,211
Total Outstanding	608,335	627,304
90 Plus Days Past Due still Accruing	$ 167	$ 149