BUSINESS SEGMENTS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
BUSINESS SEGMENTS [Abstract]
Number of operating segments	3		3
Segment Reporting Information [Line Items]
Interest income	$ 274,468	$ 253,533	$ 528,803	$ 572,236
Charge for funds used	(61,707)	(65,291)	(126,732)	(132,769)
Interest spread on funds used	212,761	188,242	402,071	439,467
Interest expense	(47,132)	(49,910)	(92,633)	(106,889)
Credit on funds provided	61,707	65,291	126,732	132,769
Interest spread on funds provided	14,575	15,381	34,099	25,880
Net interest income	227,336	203,623	436,170	465,347
Provision for loan losses	(26,500)	(55,256)	(53,006)	(131,677)	(200,159)
Depreciation, amortization and accretion	(22,574)	(10,833)	(34,937)	(47,876)
Goodwill	337,438	337,438	337,438	337,438	337,438
Segment pre-tax profit	95,730	58,734	182,310	96,676
Segment assets	21,872,708	19,967,321	21,872,708	19,967,321	20,700,537
Retail Banking [Member]
Segment Reporting Information [Line Items]
Interest income	94,964	94,361	182,754	208,848
Charge for funds used	(24,091)	(30,449)	(49,679)	(60,122)
Interest spread on funds used	70,873	63,912	133,075	148,726
Interest expense	(23,538)	(29,299)	(46,109)	(62,577)
Credit on funds provided	54,387	56,411	111,732	113,420
Interest spread on funds provided	30,849	27,112	65,623	50,843
Net interest income	101,722	91,024	198,698	199,569
Provision for loan losses	(1,787)	(22,076)	(8,943)	(48,182)
Depreciation, amortization and accretion	(5,375)	2,015	(7,215)	(7,952)
Goodwill	320,566	320,566	320,566	320,566
Segment pre-tax profit	28,703	12,562	56,393	7,031
Segment assets	6,212,906	6,370,531	6,212,906	6,370,531
Commercial Lending [Member]
Segment Reporting Information [Line Items]
Interest income	153,015	142,995	298,350	320,570
Charge for funds used	(37,356)	(32,884)	(77,553)	(62,471)
Interest spread on funds used	115,659	110,111	220,797	258,099
Interest expense	(8,002)	(5,399)	(13,987)	(13,124)
Credit on funds provided	3,456	4,311	6,934	9,291
Interest spread on funds provided	(4,546)	(1,088)	(7,053)	(3,833)
Net interest income	111,113	109,023	213,744	254,266
Provision for loan losses	(24,713)	(33,180)	(44,063)	(83,495)
Depreciation, amortization and accretion	(21,119)	(14,166)	(34,907)	(42,744)
Goodwill	16,872	16,872	16,872	16,872
Segment pre-tax profit	38,675	30,369	87,274	51,283
Segment assets	10,491,816	9,719,021	10,491,816	9,719,021
Other [Member]
Segment Reporting Information [Line Items]
Interest income	26,489	16,177	47,699	42,818
Charge for funds used	(260)	(1,958)	500	(10,176)
Interest spread on funds used	26,229	14,219	48,199	32,642
Interest expense	(15,592)	(15,212)	(32,537)	(31,188)
Credit on funds provided	3,864	4,569	8,066	10,058
Interest spread on funds provided	(11,728)	(10,643)	(24,471)	(21,130)
Net interest income	14,501	3,576	23,728	11,512
Provision for loan losses	0	0	0	0
Depreciation, amortization and accretion	3,920	1,318	7,185	2,820
Goodwill	0	0	0	0
Segment pre-tax profit	28,352	15,803	38,643	38,362
Segment assets	$ 5,167,986	$ 3,877,769	$ 5,167,986	$ 3,877,769