BUSINESS SEGMENTS (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Segment Reporting Information
Interest income	$ 266,362	$ 274,468	$ 520,412	$ 528,803
Charge for funds used	(41,563)	(61,707)	(84,652)	(126,732)
Interest spread on funds used	224,799	212,761	435,760	402,071
Interest expense	(33,205)	(47,132)	(68,337)	(92,633)
Credit on funds provided	41,563	61,707	84,652	126,732
Interest spread on funds provided	8,358	14,575	16,315	34,099
Net interest income before provision for loan losses	233,157	227,336	452,075	436,170
Provision for loan losses	15,500	26,500	33,600	53,006	95,006
Depreciation, amortization and accretion	6,005	38,346	44,674	83,412
Goodwill	337,438	337,438	337,438	337,438	337,438
Segment pre-tax profit (loss)	104,394	95,730	212,189	182,310
Segment assets	21,525,734	21,872,708	21,525,734	21,872,708	21,968,667
Retail Banking
Segment Reporting Information
Interest income	92,369	94,964	178,622	182,754
Charge for funds used	(22,149)	(24,091)	(44,409)	(49,679)
Interest spread on funds used	70,220	70,873	134,213	133,075
Interest expense	(14,218)	(23,538)	(29,766)	(46,109)
Credit on funds provided	33,731	54,387	68,771	111,732
Interest spread on funds provided	19,513	30,849	39,005	65,623
Net interest income before provision for loan losses	89,733	101,722	173,218	198,698
Provision for loan losses	10,375	1,787	17,289	8,943
Depreciation, amortization and accretion	2,466	13,427	14,399	28,127
Goodwill	320,566	320,566	320,566	320,566
Segment pre-tax profit (loss)	18,483	28,703	40,242	56,393
Segment assets	6,516,382	6,212,906	6,516,382	6,212,906
Commercial Lending
Segment Reporting Information
Interest income	152,148	153,015	295,113	298,350
Charge for funds used	(29,922)	(37,356)	(59,671)	(77,553)
Interest spread on funds used	122,226	115,659	235,442	220,797
Interest expense	(5,196)	(8,002)	(12,262)	(13,987)
Credit on funds provided	3,292	3,456	6,416	6,934
Interest spread on funds provided	(1,904)	(4,546)	(5,846)	(7,053)
Net interest income before provision for loan losses	120,322	111,113	229,596	213,744
Provision for loan losses	5,125	24,713	16,311	44,063
Depreciation, amortization and accretion	(6,474)	20,999	10,658	48,100
Goodwill	16,872	16,872	16,872	16,872
Segment pre-tax profit (loss)	63,257	38,675	123,684	87,274
Segment assets	10,058,264	10,491,816	10,058,264	10,491,816
Other
Segment Reporting Information
Interest income	21,845	26,489	46,677	47,699
Charge for funds used	10,508	(260)	19,428	500
Interest spread on funds used	32,353	26,229	66,105	48,199
Interest expense	(13,791)	(15,592)	(26,309)	(32,537)
Credit on funds provided	4,540	3,864	9,465	8,066
Interest spread on funds provided	(9,251)	(11,728)	(16,844)	(24,471)
Net interest income before provision for loan losses	23,102	14,501	49,261	23,728
Depreciation, amortization and accretion	10,013	3,920	19,617	7,185
Segment pre-tax profit (loss)	22,654	28,352	48,263	38,643
Segment assets	$ 4,951,088	$ 5,167,986	$ 4,951,088	$ 5,167,986