NON-COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 12) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Financing Receivable Allowance for Credit Losses Roll Forward
Provision for (reversal of) loan losses	$ 49,158		$ 22,364	$ 65,184
Non-covered loans
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	241,930		229,382	209,876
Allowance for unfunded loan commitments and letters of credit	(1,575)		(2,157)	1,563
Provision for (reversal of) loan losses	44,125		18,336	60,168
Charge-offs	(39,782)		(16,344)	(58,402)
Recoveries	13,476		12,713	16,177
Net (charge-offs) recoveries	(26,306)		(3,631)	(42,225)
Ending balance	258,174		241,930	229,382
Ending balance allocated to:
Loans individually evaluated for impairment	19,464		24,143	11,527
Loans collectively evaluated for impairment	238,420		217,787	217,855
Acquired with deteriorated credit quality	290
Ending balance	258,174		241,930	229,382
Non-covered loans | MetroCorp
Financing Receivable Allowance for Credit Losses Roll Forward
Charge-offs	(523)
CRE | Non-covered loans
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	64,677		69,856	66,457
Provision for (reversal of) loan losses	6,107		(6,615)	20,977
Charge-offs	(3,294)	[1]	(3,357)	(27,060)
Recoveries	1,982		4,793	9,482
Net (charge-offs) recoveries	(1,312)		1,436	(17,578)
Ending balance	69,472		64,677	69,856
Ending balance allocated to:
Loans individually evaluated for impairment	3,487		8,058	5,561
Loans collectively evaluated for impairment	65,695		56,619	64,295
Acquired with deteriorated credit quality	290
Ending balance	69,472		64,677	69,856
C&I | Non-covered loans
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	115,184		105,376	87,020
Provision for (reversal of) loan losses	40,371		12,821	35,204
Charge-offs	(29,592)		(7,405)	(21,818)
Recoveries	8,635		4,392	4,970
Net (charge-offs) recoveries	(20,957)		(3,013)	(16,848)
Ending balance	134,598		115,184	105,376
Ending balance allocated to:
Loans individually evaluated for impairment	15,202		14,539	2,835
Loans collectively evaluated for impairment	119,396		100,645	102,541
Ending balance	134,598		115,184	105,376
Residential | Non-covered loans
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	50,717		49,349	52,180
Provision for (reversal of) loan losses	(8,168)		1,918	3,255
Charge-offs	(1,103)		(3,197)	(7,700)
Recoveries	2,410		2,647	1,614
Net (charge-offs) recoveries	1,307		(550)	(6,086)
Ending balance	43,856		50,717	49,349
Ending balance allocated to:
Loans individually evaluated for impairment	774		1,546	3,131
Loans collectively evaluated for impairment	43,082		49,171	46,218
Ending balance	43,856		50,717	49,349
Consumer | Non-covered loans
Financing Receivable Allowance for Credit Losses Roll Forward
Beginning balance	11,352		4,801	4,219
Provision for (reversal of) loan losses	4,240		8,055	2,295
Charge-offs	(5,793)		(2,385)	(1,824)
Recoveries	449		881	111
Net (charge-offs) recoveries	(5,344)		(1,504)	(1,713)
Ending balance	10,248		11,352	4,801
Ending balance allocated to:
Loans individually evaluated for impairment	1
Loans collectively evaluated for impairment	10,247		11,352	4,801
Ending balance	10,248		11,352	4,801
Unallocated | Non-covered loans
Financing Receivable Allowance for Credit Losses Roll Forward
Allowance for unfunded loan commitments and letters of credit	(1,575)		(2,157)	1,563
Provision for (reversal of) loan losses	$ 1,575		$ 2,157	$ (1,563)

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