LOANS AND LEASES, Non-performing and Nonaccrual Loans and Leases (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
LOANS AND LEASES [Abstract]
Days past due of principal or interest at which loans and leases may be placed in non-accrual status	90 days
Non-performing loans and leases [Abstract]
Non-accrual loans and leases	$ 188,190	$ 207,241	$ 253,227
Loans and leases 90 days or more past due, still accruing	1,125	1,210	1,698
Restructured loans and leases still accruing	17,702	25,099	30,311
Total non-performing loans and leases	207,017	233,550	285,236
Nonaccrual loans and leases [Abstract]
Non-accrual loans and leases	188,190	207,241	253,227
Commercial and industrial segment [Member]
Non-performing loans and leases [Abstract]
Non-accrual loans and leases	7,009	9,311	11,025
Loans and leases 90 days or more past due, still accruing	22	414
Nonaccrual loans and leases [Abstract]
Non-accrual loans and leases	7,009	9,311	11,025
Real estate segment [Member] | Consumer mortgages [Member]
Non-performing loans and leases [Abstract]
Non-accrual loans and leases	39,012	36,133	46,562
Loans and leases 90 days or more past due, still accruing	842	512
Nonaccrual loans and leases [Abstract]
Non-accrual loans and leases	39,012	36,133	46,562
Real estate segment [Member] | Home equity [Member]
Non-performing loans and leases [Abstract]
Non-accrual loans and leases	4,272	3,497	2,687
Loans and leases 90 days or more past due, still accruing	0	0
Nonaccrual loans and leases [Abstract]
Non-accrual loans and leases	4,272	3,497	2,687
Real estate segment [Member] | Agricultural [Member]
Non-performing loans and leases [Abstract]
Non-accrual loans and leases	6,667	7,587	4,254
Loans and leases 90 days or more past due, still accruing	0	10
Nonaccrual loans and leases [Abstract]
Non-accrual loans and leases	6,667	7,587	4,254
Real estate segment [Member] | Commercial and industrial-owner occupied [Member]
Non-performing loans and leases [Abstract]
Non-accrual loans and leases	20,719	20,910	32,842
Loans and leases 90 days or more past due, still accruing	0	19
Nonaccrual loans and leases [Abstract]
Non-accrual loans and leases	20,719	20,910	32,842
Real estate segment [Member] | Construction, acquisition and development [Member]
Non-performing loans and leases [Abstract]
Non-accrual loans and leases	51,728	66,635	115,649
Loans and leases 90 days or more past due, still accruing	0	0
Nonaccrual loans and leases [Abstract]
Non-accrual loans and leases	51,728	66,635	115,649
Real estate segment [Member] | Commercial real estate [Member]
Non-performing loans and leases [Abstract]
Non-accrual loans and leases	55,318	57,656	35,715
Loans and leases 90 days or more past due, still accruing	0	0
Nonaccrual loans and leases [Abstract]
Non-accrual loans and leases	55,318	57,656	35,715
Credit cards segment [Member]
Non-performing loans and leases [Abstract]
Non-accrual loans and leases	418	415	509
Loans and leases 90 days or more past due, still accruing	261	228
Nonaccrual loans and leases [Abstract]
Non-accrual loans and leases	418	415	509
All other [Member]
Non-performing loans and leases [Abstract]
Non-accrual loans and leases	3,047	5,097	3,984
Loans and leases 90 days or more past due, still accruing	0	27
Nonaccrual loans and leases [Abstract]
Non-accrual loans and leases	$ 3,047	$ 5,097	$ 3,984