SEGMENTS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Results of Operations [Abstract]
Net interest revenue	$ 434,913	$ 441,142	$ 444,899
Provision for credit losses	130,081	204,016	117,324
Net interest income after provision for credit losses	304,832	237,126	327,575
Noninterest revenue	270,845	264,144	275,276
Noninterest expense	533,633	487,033	490,017
Income (loss) before income taxes	42,044	14,237	112,834
Income tax expense (benefit)	4,475	(8,705)	30,105
Net income	37,569	22,942	82,729
Selected Financial Information [Abstract]
Total assets	12,995,851	13,615,010	13,167,867
Depreciation and amortization	32,214	33,672	35,754
Community Banking [Member]
Results of Operations [Abstract]
Net interest revenue	407,648	411,936	413,125
Provision for credit losses	127,794	197,539	111,409
Net interest income after provision for credit losses	279,854	214,397	301,716
Noninterest revenue	126,807	114,736	130,544
Noninterest expense	338,125	308,299	327,020
Income (loss) before income taxes	68,536	20,834	105,240
Income tax expense (benefit)	40,454	2,914	28,079
Net income	28,082	17,920	77,161
Selected Financial Information [Abstract]
Total assets	10,169,986	10,854,511	10,879,768
Depreciation and amortization	24,167	24,910	28,831
Insurance Agencies [Member]
Results of Operations [Abstract]
Net interest revenue	329	561	625
Provision for credit losses	0	0	0
Net interest income after provision for credit losses	329	561	625
Noninterest revenue	86,955	82,327	80,714
Noninterest expense	73,793	70,830	68,857
Income (loss) before income taxes	13,491	12,058	12,482
Income tax expense (benefit)	5,423	4,786	4,918
Net income	8,068	7,272	7,564
Selected Financial Information [Abstract]
Total assets	163,995	158,919	159,585
Depreciation and amortization	3,826	4,230	4,651
General Corporate and Other [Member]
Results of Operations [Abstract]
Net interest revenue	26,936	28,645	31,149
Provision for credit losses	2,287	6,477	5,915
Net interest income after provision for credit losses	24,649	22,168	25,234
Noninterest revenue	57,083	67,081	64,018
Noninterest expense	121,715	107,904	94,140
Income (loss) before income taxes	(39,983)	(18,655)	(4,888)
Income tax expense (benefit)	(41,402)	(16,405)	(2,892)
Net income	1,419	(2,250)	(1,996)
Selected Financial Information [Abstract]
Total assets	2,661,870	2,601,580	2,128,514
Depreciation and amortization	$ 4,221	$ 4,532	$ 2,272