LOANS AND ALLOWANCE FOR LOAN LOSSES (Summary of Aging of the Loan Portfolio by Class) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	$ 27,589	$ 29,297
60-89 Days Past Due	7,221	8,730
Greater Than 90 Days and still Accruing	7,932	10,047
Purchased Impaired (net of credit mark)	91,346	105,788	138,431
Nonaccrual	17,385	19,255
Current	5,236,282	5,172,879
Total loans	5,387,755	5,345,996	5,274,198
Commercial Construction [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	374	815
60-89 Days Past Due
Greater Than 90 Days and still Accruing
Purchased Impaired (net of credit mark)	3,090	3,782
Nonaccrual	1,953	968
Current	353,019	335,715
Total loans	358,436	341,280
Commercial Real Estate - Owner Occupied [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	1,606	621
60-89 Days Past Due	174	1,542
Greater Than 90 Days and still Accruing	1,357	1,683
Purchased Impaired (net of credit mark)	31,004	31,167
Nonaccrual	4,954	1,060
Current	859,127	839,370
Total loans	898,222	875,443
Commercial Real Estate - Non-Owner Occupied [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	1,344	3,984
60-89 Days Past Due	656	237
Greater Than 90 Days and still Accruing	328	91
Purchased Impaired (net of credit mark)	19,575	28,869
Nonaccrual	2,655	5,902
Current	1,494,032	1,470,076
Total loans	1,518,590	1,509,159
Raw Land and Lots [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	235	145
60-89 Days Past Due	58	44
Greater Than 90 Days and still Accruing	109	194
Purchased Impaired (net of credit mark)	6,055	7,427
Nonaccrual	1,059	2,359
Current	190,243	201,056
Total loans	197,759	211,225
Single Family Investment Real Estate [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	1,206	2,825
60-89 Days Past Due	158	338
Greater Than 90 Days and still Accruing	251	734
Purchased Impaired (net of credit mark)	16,299	16,879
Nonaccrual	1,302	2,070
Current	397,768	389,648
Total loans	416,984	412,494
Commercial and Industrial [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	1,453	1,250
60-89 Days Past Due	271	529
Greater Than 90 Days and still Accruing	468	549
Purchased Impaired (net of credit mark)	3,338	3,855
Nonaccrual	2,540	3,286
Current	418,420	384,307
Total loans	426,490	393,776
Other Commercial [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	281	42
60-89 Days Past Due	71	2
Greater Than 90 Days and still Accruing	65
Purchased Impaired (net of credit mark)	1,794	2,256
Nonaccrual	69	74
Current	78,136	78,732
Total loans	80,416	81,106
Mortgage [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	13,710	12,851
60-89 Days Past Due	1,862	4,300
Greater Than 90 Days and still Accruing	3,313	4,095
Purchased Impaired (net of credit mark)	6,381	7,394
Nonaccrual	2,397	2,485
Current	439,141	447,026
Total loans	466,804	478,151
Consumer Construction [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	717	120
60-89 Days Past Due	700
Greater Than 90 Days and still Accruing	469	844
Purchased Impaired (net of credit mark)	504	516
Nonaccrual
Current	63,508	72,688
Total loans	65,898	74,168
Indirect Auto [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	1,345	1,593
60-89 Days Past Due	181	263
Greater Than 90 Days and still Accruing	272	317
Purchased Impaired (net of credit mark)
Nonaccrual
Current	201,571	197,238
Total loans	203,369	199,411
Indirect Marine [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	52	150
60-89 Days Past Due
Greater Than 90 Days and still Accruing
Purchased Impaired (net of credit mark)
Nonaccrual	48	201
Current	43,543	42,839
Total loans	43,643	43,190
HELOCs [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	3,014	3,082
60-89 Days Past Due	1,119	955
Greater Than 90 Days and still Accruing	685	820
Purchased Impaired (net of credit mark)	1,889	2,000
Nonaccrual	205	258
Current	484,204	493,464
Total loans	491,116	500,579
Credit Card [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	114	232
60-89 Days Past Due	64	108
Greater Than 90 Days and still Accruing	265	219
Purchased Impaired (net of credit mark)
Nonaccrual
Current	24,248	23,666
Total loans	24,691	24,225
Other Consumer [Member]
Summary of aging of the loan portfolio, by class
30-59 Days Past Due	2,138	1,587
60-89 Days Past Due	1,907	412
Greater Than 90 Days and still Accruing	350	501
Purchased Impaired (net of credit mark)	1,417	1,643
Nonaccrual	203	592
Current	189,322	197,054
Total loans	$ 195,337	$ 201,789