NON-COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 12) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013	Jun. 30, 2014		Jun. 30, 2013
Financing Receivable Allowance for Credit Losses Roll Forward
Provision for loan losses	$ 8,000		$ 9,000	$ 14,933		$ 13,327
Non-covered loans
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	245,618		228,796	241,930		229,382
Provision for loan losses	8,944		8,277	16,898		7,515
Provision allocation for unfunded loan commitments and letters of credit	(829)		432	(1,044)		1,148
Charge-offs	(8,276)		(5,993)	(14,206)		(8,916)
Recoveries	1,011		1,968	2,890		4,351
Net charge-offs	(7,265)		(4,025)	(11,316)		(4,565)
Ending balance	246,468		233,480	246,468		233,480
Ending balance allocated to:
Individually evaluated for impairment	24,841		13,147	24,841		13,147
Collectively evaluated for impairment	221,257		220,333	221,257		220,333
Acquired with deteriorated credit quality	370			370
Ending balance	246,468		233,480	246,468		233,480
Non-covered loans | MetroCorp
Financing Receivable Allowance for Credit Losses Roll Forward
Charge-offs	523			523
Residential | Non-covered loans
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	47,827		46,880	50,717		49,349
Provision for loan losses	(2,046)		704	(4,790)		(2,222)
Charge-offs	(61)		(550)	(343)		(861)
Recoveries	63		303	199		1,071
Net charge-offs	2		(247)	(144)		210
Ending balance	45,783		47,337	45,783		47,337
Ending balance allocated to:
Individually evaluated for impairment	1,377		1,508	1,377		1,508
Collectively evaluated for impairment	44,406		45,829	44,406		45,829
Ending balance	45,783		47,337	45,783		47,337
Commercial Real Estate ("CRE") | Non-covered loans
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	62,739		72,958	64,677		69,856
Provision for loan losses	(1,376)		(426)	(3,823)		3,392
Charge-offs	(1,314)	[1]	(762)	(1,634)	[1]	(1,767)
Recoveries	551		1,060	1,380		1,349
Net charge-offs	(763)		298	(254)		(418)
Ending balance	60,600		72,830	60,600		72,830
Ending balance allocated to:
Individually evaluated for impairment	4,546		7,931	4,546		7,931
Collectively evaluated for impairment	55,684		64,899	55,684		64,899
Acquired with deteriorated credit quality	370			370
Ending balance	60,600		72,830	60,600		72,830
Commercial and Industrial ("C&I") | Non-covered loans
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	124,201		102,346	115,184		105,376
Provision for loan losses	10,784		6,241	24,215		3,941
Charge-offs	(6,899)		(3,816)	(12,224)		(5,077)
Recoveries	393		605	1,304		1,136
Net charge-offs	(6,506)		(3,211)	(10,920)		(3,941)
Ending balance	128,479		105,376	128,479		105,376
Ending balance allocated to:
Individually evaluated for impairment	18,918		3,708	18,918		3,708
Collectively evaluated for impairment	109,561		101,668	109,561		101,668
Ending balance	128,479		105,376	128,479		105,376
Consumer | Non-covered loans
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	10,851		6,612	11,352		4,801
Provision for loan losses	753		2,190	252		3,552
Charge-offs	(2)		(865)	(5)		(1,211)
Recoveries	4			7		795
Net charge-offs	2		(865)	2		(416)
Ending balance	11,606		7,937	11,606		7,937
Ending balance allocated to:
Collectively evaluated for impairment	11,606		7,937	11,606		7,937
Ending balance	11,606		7,937	11,606		7,937
Unallocated | Non-covered loans
Financing Receivable Allowance for Credit Losses Roll Forward
Provision for loan losses	829		(432)	1,044		(1,148)
Provision allocation for unfunded loan commitments and letters of credit	$ (829)		$ 432	$ (1,044)		$ 1,148

[1] Includes charge-off of $523 thousand relating to PCI loans acquired from MetroCorp.