NON COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 7) (USD $) In Thousands, unless otherwise specified	3 Months Ended											12 Months Ended
	Dec. 31, 2011		Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011		Dec. 31, 2010		Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Covered loans
Percentage of total general reserve for allowance for loan losses allocated to covered loans	3.10%						1.80%					3.10%		1.80%
Allowance on covered loans	$ (6,647)						$ (4,225)					$ (6,647)		$ (4,225)
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance					234,633						238,833	234,633		238,833
Provision for loan losses	20,000		22,000	26,500	26,506		29,834		38,648	55,256	76,421	95,006		200,159		528,666
Allowance for unfunded loan commitments and letters of credit												(1,048)		(1,833)
Charge-offs												(124,691)		(225,203)
Recoveries												12,623		22,677
Net charge-offs												(112,068)		(202,526)
Ending balance	216,523						234,633					216,523		234,633		238,833
Ending balance allocated to:
Loans individually evaluated for impairment	13,041						10,024					13,041		10,024
Loans collectively evaluated for impairment	203,482						224,609					203,482		224,609
Ending balance	216,523						234,633					216,523		234,633		238,833
Residential
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance					49,491						38,025	49,491		38,025
Provision for loan losses												15,416		59,525
Charge-offs												(13,323)		(49,685)
Recoveries												596		1,626
Net charge-offs												(12,727)		(48,059)
Ending balance	52,180						49,491					52,180		49,491
Ending balance allocated to:
Loans individually evaluated for impairment	2,255						309					2,255		309
Loans collectively evaluated for impairment	49,925						49,182					49,925		49,182
Ending balance	52,180						49,491					52,180		49,491
Commercial Real Estate ("CRE")
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance					117,752						147,591	117,752		147,591
Provision for loan losses												22,817		97,548
Charge-offs												(78,803)		(137,460)
Recoveries												4,691		10,073
Net charge-offs												(74,112)		(127,387)
Ending balance	66,457						117,752					66,457		117,752
Ending balance allocated to:
Loans individually evaluated for impairment	5,951						7,247					5,951		7,247
Loans collectively evaluated for impairment	60,506						110,505					60,506		110,505
Ending balance	66,457						117,752					66,457		117,752
Commercial and Industrial ("C&I")
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance					59,737						50,487	59,737		50,487
Provision for loan losses												50,848		34,613
Charge-offs												(30,606)		(35,479)
Recoveries												7,041		10,116
Net charge-offs												(23,565)		(25,363)
Ending balance	87,020						59,737					87,020		59,737
Ending balance allocated to:
Loans individually evaluated for impairment	4,835						2,468					4,835		2,468
Loans collectively evaluated for impairment	82,185						57,269					82,185		57,269
Ending balance	87,020						59,737					87,020		59,737
Consumer
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance					3,428						2,730	3,428		2,730
Provision for loan losses												2,455		2,415
Charge-offs												(1,959)		(2,579)
Recoveries												295		862
Net charge-offs												(1,664)		(1,717)
Ending balance	4,219						3,428					4,219		3,428
Ending balance allocated to:
Loans collectively evaluated for impairment	4,219						3,428					4,219		3,428
Ending balance	4,219						3,428					4,219		3,428
Covered Loans Subject to Allowance For Loan Losses
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance					4,225	[1]						4,225	[1]
Provision for loan losses												2,422	[1]	4,225	[1]
Ending balance	6,647	[1]					4,225	[1]				6,647	[1]	4,225	[1]
Ending balance allocated to:
Loans collectively evaluated for impairment	6,647	[1]					4,225	[1]				6,647	[1]	4,225	[1]
Ending balance	6,647	[1]					4,225	[1]				6,647	[1]	4,225	[1]
Unallocated
Financing Receivable Allowance for Credit Losses Roll Forward
Provision for loan losses												1,048		1,833
Allowance for unfunded loan commitments and letters of credit												$ (1,048)		$ (1,833)

[1] This allowance is related to drawdowns on commitments that were in existence as of the acquisition dates of WFIB and UCB and, therefore, are covered under the shared-loss agreements with the FDIC. Allowance on these subsequent drawdowns is accounted for as part of the allowance for loan losses.