NON-COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 13) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended				12 Months Ended
	Jun. 30, 2013		Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012		Dec. 31, 2012
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	$ 238,906			$ 234,535		$ 216,523		$ 216,523
Provision for loan losses	9,000		15,500	13,327		33,600		65,184
Allowance for unfunded loan commitments and letters of credit	432			(1,148)				1,563
Charge-offs	(7,197)			(10,252)				(64,912)
Recoveries	1,968			4,351				16,177
Net charge-offs	(5,229)			(5,901)		(22,000)		(48,735)
Ending balance	243,109			243,109				234,535
Ending balance allocated to:
Loans individually evaluated for impairment	13,147			13,147				11,527
Loans collectively evaluated for impairment	227,433			227,433				223,008
Covered loans acquired with deteriorated credit quality	2,529	[1]		2,529	[1]
Ending balance	243,109			243,109				234,535
Residential
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	46,880			49,349		52,180		52,180
Provision for loan losses	704			(2,222)				3,255
Charge-offs	(550)			(861)				(7,700)
Recoveries	303			1,071				1,614
Net charge-offs	(247)			210				(6,086)
Ending balance	47,337			47,337				49,349
Ending balance allocated to:
Loans individually evaluated for impairment	1,508			1,508				3,131
Loans collectively evaluated for impairment	45,829			45,829				46,218
Ending balance	47,337			47,337				49,349
Commercial Real Estate ("CRE")
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	72,958			69,856		66,457		66,457
Provision for loan losses	(426)			3,392				20,977
Charge-offs	(762)			(1,767)				(27,060)
Recoveries	1,060			1,349				9,482
Net charge-offs	298			(418)				(17,578)
Ending balance	72,830			72,830				69,856
Ending balance allocated to:
Loans individually evaluated for impairment	7,931			7,931				5,561
Loans collectively evaluated for impairment	64,899			64,899				64,295
Ending balance	72,830			72,830				69,856
Commercial and Industrial ("C&I")
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	102,346			105,376		87,020		87,020
Provision for loan losses	6,241			3,941				35,204
Charge-offs	(3,816)			(5,077)				(21,818)
Recoveries	605			1,136				4,970
Net charge-offs	(3,211)			(3,941)				(16,848)
Ending balance	105,376			105,376				105,376
Ending balance allocated to:
Loans individually evaluated for impairment	3,708			3,708				2,835
Loans collectively evaluated for impairment	101,668			101,668				102,541
Ending balance	105,376			105,376				105,376
Consumer
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	6,612			4,801		4,219		4,219
Provision for loan losses	2,190			3,552				2,295
Charge-offs	(865)			(1,211)				(1,824)
Recoveries				795				111
Net charge-offs	(865)			(416)				(1,713)
Ending balance	7,937			7,937				4,801
Ending balance allocated to:
Loans collectively evaluated for impairment	7,937			7,937				4,801
Ending balance	7,937			7,937				4,801
Covered Loans under ASC 310-10 Subject to Allowance for Loan Losses
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	8,118	[2]		5,153	[2]	6,647	[2]	6,647	[2]
Provision for loan losses	186	[2]		3,283	[2]			5,016	[2]
Charge-offs	(1,204)	[2]		(1,336)	[2]			(6,510)	[2]
Net charge-offs	(1,204)	[2]		(1,336)	[2]			(6,510)	[2]
Ending balance	7,100	[2]		7,100	[2]			5,153	[2]
Ending balance allocated to:
Loans collectively evaluated for impairment	7,100	[2]		7,100	[2]			5,153	[2]
Ending balance	7,100	[2]		7,100	[2]			5,153	[2]
Covered Loans under ASC 310-30 Subject to Allowance for Loan Losses
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	1,992
Provision for loan losses	537			2,529
Ending balance	2,529			2,529
Ending balance allocated to:
Covered loans acquired with deteriorated credit quality	2,529	[1]		2,529	[1]
Ending balance	2,529			2,529
Unallocated
Financing Receivable Allowance for Credit Losses Roll Forward
Provision for loan losses	(432)			(1,148)				(1,563)
Allowance for unfunded loan commitments and letters of credit	$ 432			$ 1,148				$ 1,563

[1] The Company has elected to account for covered loans acquired in the FDIC-assisted acquisitions under ASC 310-30, excluding any additional advances subsequent to acquisition date.

[2] 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 drawdownsis accounted for as part of the allowance for loan losses.