ALLOWANCE FOR CREDIT LOSSES (1) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	$ 156,728	$ 234,923
Allowance for impaired loans and leases	10,541	39,708
Allowance for all other loans and leases	153,925	155,410
Total allowance	164,466	195,118	196,913	176,043
Construction, acquisition and development [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	61,335	128,179
Allowance for impaired loans and leases	4,350	21,581
Commercial and industrial segment [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	4,845	7,833
Allowance for impaired loans and leases	1,241	4,071
Allowance for all other loans and leases	22,045	16,653
Total allowance	23,286	20,724	22,479
Real estate segment [Member] | Consumer mortgages [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	15,107	31,793
Allowance for impaired loans and leases	1,103	4,386
Allowance for all other loans and leases	34,863	32,143
Total allowance	35,966	36,529	35,540
Real estate segment [Member] | Home equity [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	1,380	675
Allowance for impaired loans and leases	111	48
Allowance for all other loans and leases	5,894	8,582
Total allowance	6,005	8,630	7,305
Real estate segment [Member] | Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	5,382	3,096
Allowance for impaired loans and leases	92	380
Allowance for all other loans and leases	3,209	3,541
Total allowance	3,301	3,921	4,997
Real estate segment [Member] | Commercial and industrial-owner occupied [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	16,720	24,801
Allowance for impaired loans and leases	864	3,601
Allowance for all other loans and leases	19,314	18,328
Total allowance	20,178	21,929	20,403
Real estate segment [Member] | Construction, acquisition and development [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	61,335	128,179
Allowance for impaired loans and leases	4,350	21,581
Allowance for all other loans and leases	17,555	23,981
Total allowance	21,905	45,562	59,048
Real estate segment [Member] | Commercial [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	50,413	36,122
Allowance for impaired loans and leases	2,720	5,324
Allowance for all other loans and leases	37,361	34,120
Total allowance	40,081	39,444	33,439
Credit cards segment [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	0	0
Allowance for impaired loans and leases	0	0
Allowance for all other loans and leases	3,611	4,021
Total allowance	3,611	4,021	4,126
All other receivables [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	1,546	2,424
Allowance for impaired loans and leases	60	317
Allowance for all other loans and leases	10,073	14,041
Total allowance	$ 10,133	$ 14,358	$ 9,576