SEGMENT INFORMATION (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Segment Reporting Information
Interest income	$ 276,521	$ 254,162	$ 266,362	$ 254,050	$ 268,904	$ 282,741	$ 274,468	$ 254,335	$ 1,051,095		$ 1,080,448		$ 1,095,831
Charge for funds used									(160,092)		(232,464)		(239,910)
Interest spread on funds used									891,003		847,984		855,921
Interest expense	(31,577)	(32,254)	(33,205)	(35,132)	(39,830)	(44,959)	(47,132)	(45,501)	(132,168)		(177,422)		(201,117)
Credit on funds provided									160,092		232,464		239,910
Interest spread on funds provided									27,924		55,042		38,793
Net interest income	244,944	221,908	233,157	218,918	229,074	237,782	227,336	208,834	918,927		903,026		894,714
Provision for loan losses									65,184		95,006		200,159
Depreciation, amortization and accretion									43,751	[1]	128,254	[1]	162,416	[1]
Goodwill	337,438				337,438				337,438		337,438		337,438
Segment pre-tax profit (loss)	108,200	105,203	104,394	107,795	103,339	97,685	95,730	86,580	425,592		383,334		255,909
Segment assets	22,536,110				21,968,667				22,536,110		21,968,667		20,700,537
Retail Banking
Segment Reporting Information
Interest income									356,244		358,853		355,198
Charge for funds used									(85,811)		(94,098)		(113,121)
Interest spread on funds used									270,433		264,755		242,077
Interest expense									(57,401)		(85,356)		(112,703)
Credit on funds provided									130,713		202,080		209,040
Interest spread on funds provided									73,312		116,724		96,337
Net interest income									343,745		381,479		338,414
Provision for loan losses									28,729		27,888		73,021
Depreciation, amortization and accretion									12,869	[1]	43,899	[1]	59,060	[1]
Goodwill	320,566				320,566				320,566		320,566		320,566
Segment pre-tax profit (loss)									74,836		102,217		(4,992)
Segment assets	6,552,217				6,530,138				6,552,217		6,530,138		6,580,118
Commercial Banking
Segment Reporting Information
Interest income									617,041		619,766		659,703
Charge for funds used									(118,688)		(142,056)		(156,303)
Interest spread on funds used									498,353		477,710		503,400
Interest expense									(23,226)		(31,407)		(24,756)
Credit on funds provided									13,138		13,863		14,346
Interest spread on funds provided									(10,088)		(17,544)		(10,410)
Net interest income									488,265		460,166		492,990
Provision for loan losses									36,455		67,118		127,138
Depreciation, amortization and accretion									(13,277)	[1]	62,803	[1]	100,546	[1]
Goodwill	16,872				16,872				16,872		16,872		16,872
Segment pre-tax profit (loss)									266,168		227,766		157,932
Segment assets	10,421,160				10,157,195				10,421,160		10,157,195		9,856,661
Other
Segment Reporting Information
Interest income									77,810		101,829		80,930
Charge for funds used									44,407		3,690		29,514
Interest spread on funds used									122,217		105,519		110,444
Interest expense									(51,541)		(60,659)		(63,658)
Credit on funds provided									16,241		16,521		16,524
Interest spread on funds provided									(35,300)		(44,138)		(47,134)
Net interest income									86,917		61,381		63,310
Depreciation, amortization and accretion									44,159	[1]	21,552	[1]	2,810	[1]
Segment pre-tax profit (loss)									84,588		53,351		102,969
Segment assets	$ 5,562,733				$ 5,281,334				$ 5,562,733		$ 5,281,334		$ 4,263,758

[1] Includes amortization and accretion related to the FDIC indemnification asset.