LOAN AND LEASES (1) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	$ 45,618	$ 37,336
60-89 Days Past Due	27,512	20,207
90 Plus Days Past Due	49,165	78,309
Total Past Due	122,295	135,852
Current	8,557,674	8,734,459
Total Outstanding	8,679,969	8,870,311
90 Plus Days Past Due still Accruing	1,442	3,434	7,354
Commercial and industrial segment [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	5,505	5,571
60-89 Days Past Due	949	4,209
90 Plus Days Past Due	4,671	4,193
Total Past Due	11,125	13,973
Current	1,451,594	1,459,755
Total Outstanding	1,462,719	1,473,728
90 Plus Days Past Due still Accruing	45	12
Real estate segment [Member] | Consumer mortgages [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	14,122	15,740
60-89 Days Past Due	5,560	6,485
90 Plus Days Past Due	14,521	14,569
Total Past Due	34,203	36,794
Current	1,854,580	1,908,396
Total Outstanding	1,888,783	1,945,190
90 Plus Days Past Due still Accruing	1,027	2,974
Real estate segment [Member] | Home equity [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	1,916	1,837
60-89 Days Past Due	183	265
90 Plus Days Past Due	169	594
Total Past Due	2,268	2,696
Current	490,565	511,666
Total Outstanding	492,833	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	624	666
60-89 Days Past Due	837	54
90 Plus Days Past Due	4,090	719
Total Past Due	5,551	1,439
Current	252,182	238,048
Total Outstanding	257,733	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	4,121	2,199
60-89 Days Past Due	1,111	844
90 Plus Days Past Due	6,807	12,977
Total Past Due	12,039	16,020
Current	1,297,592	1,285,555
Total Outstanding	1,309,631	1,301,575
90 Plus Days Past Due still Accruing	119	0
Real estate segment [Member] | Construction, acquisition and development [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	12,513	4,826
60-89 Days Past Due	15,602	4,955
90 Plus Days Past Due	13,395	33,584
Total Past Due	41,510	43,365
Current	782,182	864,997
Total Outstanding	823,692	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	4,485	3,778
60-89 Days Past Due	1,656	2,702
90 Plus Days Past Due	4,208	9,397
Total Past Due	10,349	15,877
Current	1,728,167	1,738,145
Total Outstanding	1,738,516	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	539	595
60-89 Days Past Due	300	303
90 Plus Days Past Due	525	697
Total Past Due	1,364	1,595
Current	100,041	104,686
Total Outstanding	101,405	106,281
90 Plus Days Past Due still Accruing	236	299
All other receivables [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	1,793	2,124
60-89 Days Past Due	1,314	390
90 Plus Days Past Due	779	1,579
Total Past Due	3,886	4,093
Current	600,771	623,211
Total Outstanding	604,657	627,304
90 Plus Days Past Due still Accruing	$ 15	$ 149