SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Results of Operations [Abstract]
Net interest revenue	$ 103,081	$ 98,213	$ 204,604	$ 196,291
Provision for credit losses		3,000	0	7,000
Net interest revenue, after provision for credit losses	103,081	95,213	204,604	189,291
Noninterest revenue	69,838	76,109	136,355	147,427
Noninterest expense	127,954	142,251	254,661	277,622
Income before income taxes	44,965	29,071	86,298	59,096
Income tax expense (benefit)	14,097	8,316	26,986	17,536
Net income	30,868	20,755	59,312	41,560
Selected Financial Information [Abstract]
Total assets at end of period	12,985,887	13,217,705	12,985,887	13,217,705	13,029,733	[1]
Depreciation and amortization	8,144	7,327	15,775	14,781
Community Banking [Member]
Results of Operations [Abstract]
Net interest revenue	94,582	92,725	187,897	184,969
Provision for credit losses	(548)	2,139	476	6,240
Net interest revenue, after provision for credit losses	95,130	90,586	187,421	178,729
Noninterest revenue	24,010	26,720	47,936	53,227
Noninterest expense	80,201	76,557	161,974	167,762
Income before income taxes	38,939	40,749	73,383	64,194
Income tax expense (benefit)	12,697	13,447	23,770	21,197
Net income	26,242	27,302	49,613	42,997
Selected Financial Information [Abstract]
Total assets at end of period	9,565,492	9,928,278	9,565,492	9,928,278
Depreciation and amortization	6,456	5,726	12,038	11,516
Insurance Agencies [Member]
Results of Operations [Abstract]
Net interest revenue	30	40	58	90
Net interest revenue, after provision for credit losses	30	40	58	90
Noninterest revenue	28,872	25,793	60,493	52,323
Noninterest expense	24,371	21,991	48,686	43,398
Income before income taxes	4,531	3,842	11,865	9,015
Income tax expense (benefit)	1,807	1,542	4,725	3,619
Net income	2,724	2,300	7,140	5,396
Selected Financial Information [Abstract]
Total assets at end of period	205,756	194,050	205,756	194,050
Depreciation and amortization	1,346	884	2,623	1,778
General Corporate And Other [Member]
Results of Operations [Abstract]
Net interest revenue	8,469	5,448	16,649	11,232
Provision for credit losses	548	861	(476)	760
Net interest revenue, after provision for credit losses	7,921	4,587	17,125	10,472
Noninterest revenue	16,956	23,596	27,926	41,877
Noninterest expense	23,382	43,703	44,001	66,462
Income before income taxes	1,495	(15,520)	1,050	(14,113)
Income tax expense (benefit)	(407)	(6,673)	(1,509)	(7,280)
Net income	1,902	(8,847)	2,559	(6,833)
Selected Financial Information [Abstract]
Total assets at end of period	3,214,639	3,095,377	3,214,639	3,095,377
Depreciation and amortization	$ 342	$ 717	$ 1,114	$ 1,487

[1] Derived from audited financial statements.See accompanying notes to consolidated financial statements.