ALLOWANCE FOR CREDIT LOSSES (Details) (USD $) In Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Changes in the allowance for credit losses [Roll Forward]
Balance, beginning of period	$ 196,913	$ 176,043	$ 176,043
Charge-offs	(90,003)	(83,742)	(191,022)
Recoveries	4,998	2,570	7,876
Provision	85,719	105,873	204,016
Balance, end of period	197,627	200,744	196,913
Commercial and industrial segment [Member]
Changes in the allowance for credit losses [Roll Forward]
Balance, beginning of period	22,479	21,154	21,154
Charge-offs	(14,365)	(7,275)	(11,879)
Recoveries	773	305	1,330
Provision	13,953	8,334	11,874
Balance, end of period	22,840	22,518	22,479
Consumer mortgage [Member] | Real estate segment [Member]
Changes in the allowance for credit losses [Roll Forward]
Balance, beginning of period	35,540	37,048	37,048
Charge-offs	(4,889)	(7,591)	(16,280)
Recoveries	363	882	1,448
Provision	6,031	2,256	13,324
Balance, end of period	37,045	32,595	35,540
Home equity [Member] | Real estate segment [Member]
Changes in the allowance for credit losses [Roll Forward]
Balance, beginning of period	7,305	7,218	7,218
Charge-offs	(2,473)	(2,285)	(5,215)
Recoveries	91	95	179
Provision	2,697	1,751	5,123
Balance, end of period	7,620	6,779	7,305
Agricultural [Member] | Real estate segment [Member]
Changes in the allowance for credit losses [Roll Forward]
Balance, beginning of period	4,997	4,192	4,192
Charge-offs	(965)	(680)	(1,201)
Recoveries	47	0	12
Provision	630	255	1,994
Balance, end of period	4,709	3,767	4,997
Commercial and industrial-owner occupied [Member] | Real estate segment [Member]
Changes in the allowance for credit losses [Roll Forward]
Balance, beginning of period	20,403	22,989	22,989
Charge-offs	(4,944)	(6,310)	(9,200)
Recoveries	194	51	399
Provision	8,991	5,803	6,215
Balance, end of period	24,644	22,533	20,403
Construction, acquisition and development [Member] | Real estate segment [Member]
Changes in the allowance for credit losses [Roll Forward]
Balance, beginning of period	59,048	46,193	46,193
Charge-offs	(49,126)	(49,090)	(122,596)
Recoveries	2,057	267	1,706
Provision	41,941	70,935	133,745
Balance, end of period	53,920	68,305	59,048
Commercial [Member] | Real estate segment [Member]
Changes in the allowance for credit losses [Roll Forward]
Balance, beginning of period	33,439	26,694	26,694
Charge-offs	(6,111)	(4,871)	(14,084)
Recoveries	405	39	845
Provision	7,560	6,781	19,984
Balance, end of period	35,293	28,643	33,439
Credit cards segment [Member]
Changes in the allowance for credit losses [Roll Forward]
Balance, beginning of period	4,126	3,481	3,481
Charge-offs	(1,606)	(2,523)	(4,559)
Recoveries	494	369	829
Provision	473	1,984	4,375
Balance, end of period	3,487	3,311	4,126
All other receivables [Member]
Changes in the allowance for credit losses [Roll Forward]
Balance, beginning of period	9,576	7,074	7,074
Charge-offs	(5,524)	(3,117)	(6,008)
Recoveries	574	562	1,128
Provision	3,443	7,774	7,382
Balance, end of period	$ 8,069	$ 12,293	$ 9,576