LOANS AND LEASES, Aging (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	$ 52,096	$ 71,328
60-89 Days Past Due	31,958	26,908
90 Plus Days Past Due	116,314	150,643
Total Past Due	200,368	248,879
Current	9,014,185	9,084,228
Total Outstanding	9,214,553	9,333,107
90 Plus Days Past Due still Accruing	3,980	8,500	17,696
Commercial and industrial segment [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	7,022	13,037
60-89 Days Past Due	1,691	848
90 Plus Days Past Due	2,503	12,000
Total Past Due	11,216	25,885
Current	1,515,470	1,465,298
Total Outstanding	1,526,686	1,491,183
90 Plus Days Past Due still Accruing	118	675
Real estate segment [Member] | Consumer mortgage [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	14,463	16,937
60-89 Days Past Due	7,639	4,481
90 Plus Days Past Due	12,713	20,640
Total Past Due	34,815	42,058
Current	1,936,684	1,909,505
Total Outstanding	1,971,499	1,951,563
90 Plus Days Past Due still Accruing	2,482	6,521
Real estate segment [Member] | Home equity [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	2,779	1,258
60-89 Days Past Due	348	800
90 Plus Days Past Due	912	755
Total Past Due	4,039	2,813
Current	527,748	540,459
Total Outstanding	531,787	543,272
90 Plus Days Past Due still Accruing	242	173
Real estate segment [Member] | Agricultural [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	2,600	1,140
60-89 Days Past Due	318	3,450
90 Plus Days Past Due	2,841	3,527
Total Past Due	5,759	8,117
Current	249,551	244,175
Total Outstanding	255,310	252,292
90 Plus Days Past Due still Accruing	0	123
Real estate segment [Member] | Commercial and industrial-owner occupied [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	5,169	9,260
60-89 Days Past Due	2,405	1,290
90 Plus Days Past Due	12,518	7,323
Total Past Due	20,092	17,873
Current	1,346,642	1,313,600
Total Outstanding	1,366,734	1,331,473
90 Plus Days Past Due still Accruing	0	20
Real estate segment [Member] | Construction, acquisition and development [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	11,375	22,436
60-89 Days Past Due	17,150	9,837
90 Plus Days Past Due	64,323	94,264
Total Past Due	92,848	126,537
Current	967,827	1,048,206
Total Outstanding	1,060,675	1,174,743
90 Plus Days Past Due still Accruing	432	197
Real estate segment [Member] | Commercial [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	5,433	4,409
60-89 Days Past Due	1,758	4,712
90 Plus Days Past Due	18,980	10,507
Total Past Due	26,171	19,628
Current	1,738,477	1,797,323
Total Outstanding	1,764,648	1,816,951
90 Plus Days Past Due still Accruing	19	0
Credit cards segment [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	530	793
60-89 Days Past Due	337	373
90 Plus Days Past Due	630	780
Total Past Due	1,497	1,946
Current	100,458	104,399
Total Outstanding	101,955	106,345
90 Plus Days Past Due still Accruing	299	330
All other receivables [Member]
Aging of loan and lease portfolio [Abstract]
30-59 Days Past Due	2,725	2,058
60-89 Days Past Due	312	1,117
90 Plus Days Past Due	894	847
Total Past Due	3,931	4,022
Current	631,328	661,263
Total Outstanding	635,259	665,285
90 Plus Days Past Due still Accruing	$ 388	$ 461