SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Results of Operations [Abstract]
Net interest revenue	$ 105,610	$ 109,437
Provision for credit losses	10,000	53,479
Net interest revenue after provision for credit losses	95,610	55,958
Noninterest revenue	72,360	68,311
Noninterest expense	135,680	130,010
Income (loss) before income taxes	32,290	(5,741)
Income tax expense (benefit)	9,424	(5,247)
Net income (loss)	22,866	(494)
Selected Financial Information [Abstract]
Total assets at end of period	13,307,572	13,547,238	12,995,851
Depreciation and amortization	7,595	8,330
Community Banking [Member]
Results of Operations [Abstract]
Net interest revenue	107,652	102,663
Provision for credit losses	10,228	53,241
Net interest revenue after provision for credit losses	97,424	49,422
Noninterest revenue	31,185	27,991
Noninterest expense	99,059	82,710
Income (loss) before income taxes	29,550	(5,297)
Income tax expense (benefit)	9,172	(3,926)
Net income (loss)	20,378	(1,371)
Selected Financial Information [Abstract]
Total assets at end of period	10,765,843	10,636,472
Depreciation and amortization	6,022	6,273
Insurance Agencies [Member]
Results of Operations [Abstract]
Net interest revenue	73	94
Provision for credit losses	0	0
Net interest revenue after provision for credit losses	73	94
Noninterest revenue	23,151	22,538
Noninterest expense	18,698	18,060
Income (loss) before income taxes	4,526	4,572
Income tax expense (benefit)	1,819	1,822
Net income (loss)	2,707	2,750
Selected Financial Information [Abstract]
Total assets at end of period	175,763	164,488
Depreciation and amortization	874	975
General Corporate and Other [Member]
Results of Operations [Abstract]
Net interest revenue	(2,115)	6,680
Provision for credit losses	(228)	238
Net interest revenue after provision for credit losses	(1,887)	6,442
Noninterest revenue	18,024	17,782
Noninterest expense	17,923	29,240
Income (loss) before income taxes	(1,786)	(5,016)
Income tax expense (benefit)	(1,567)	(3,143)
Net income (loss)	(219)	(1,873)
Selected Financial Information [Abstract]
Total assets at end of period	2,365,966	2,746,278
Depreciation and amortization	$ 699	$ 1,082