LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014		Mar. 31, 2014	Dec. 31, 2013
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Allowance for loan losses	$ (257,738)		$ (261,679)
Loans, net	21,116,931	[1]	21,468,270	[1]
Non-PCI loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Loans, net	19,879,588		20,146,871
PCI loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Loans, net	1,237,343	[1]	1,321,399	[1]
Loans Receivable
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	21,375,568	[1]	21,727,145	[1]
Unearned fees, premiums and discounts, net	(899)	[1]	2,804	[1]
Allowance for loan losses	(257,738)	[1]	(261,679)	[1]	(252,136)	(249,675)
Loans Receivable | Non-PCI loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	20,137,582		20,405,032
Unearned fees, premiums and discounts, net	(899)		2,804
Allowance for loan losses	(257,095)		(260,965)		(249,934)	(247,406)
Loans Receivable | Non-PCI loans | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	19,412,805		19,625,603
Loans Receivable | Non-PCI loans | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	184,514		213,007
Loans Receivable | Non-PCI loans | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	539,783		565,834
Loans Receivable | Non-PCI loans | Doubtful
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	426		533
Loans Receivable | Non-PCI loans | Loss
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	54		55
Loans Receivable | PCI loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,237,986	[1]	1,322,113	[1]
Allowance for loan losses	(643)	[1]	(714)	[1]	(2,202)	(2,269)
Loans Receivable | PCI loans | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,036,513		1,089,726
Loans Receivable | PCI loans | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	15,193		18,688
Loans Receivable | PCI loans | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	186,280		213,699
CRE | Loans Receivable
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	7,045,421	[1]	6,819,513	[1]
CRE | Loans Receivable | Income producing
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	6,455,177	[1]	6,256,059	[1]
CRE | Loans Receivable | Construction
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	367,460	[1]	332,287	[1]
CRE | Loans Receivable | Land
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	222,784	[1]	231,167	[1]
CRE | Loans Receivable | Non-PCI loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	6,371,041		6,102,216
Allowance for loan losses	(69,740)		(72,263)		(63,627)	(70,154)
CRE | Loans Receivable | Non-PCI loans | Income producing
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	5,802,931		5,568,046
CRE | Loans Receivable | Non-PCI loans | Income producing | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	5,488,698		5,243,640
CRE | Loans Receivable | Non-PCI loans | Income producing | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	56,245		54,673
CRE | Loans Receivable | Non-PCI loans | Income producing | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	257,988		269,733
CRE | Loans Receivable | Non-PCI loans | Construction
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	358,118		319,843
CRE | Loans Receivable | Non-PCI loans | Construction | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	353,799		310,259
CRE | Loans Receivable | Non-PCI loans | Construction | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	703		11
CRE | Loans Receivable | Non-PCI loans | Construction | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	3,616		9,573
CRE | Loans Receivable | Non-PCI loans | Land
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	209,992		214,327
CRE | Loans Receivable | Non-PCI loans | Land | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	187,364		185,220
CRE | Loans Receivable | Non-PCI loans | Land | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	5,701		5,701
CRE | Loans Receivable | Non-PCI loans | Land | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	16,927		23,406
CRE | Loans Receivable | PCI loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	674,380	[1]	717,297	[1]
CRE | Loans Receivable | PCI loans | Income producing
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	652,246	[1]	688,013	[1]
CRE | Loans Receivable | PCI loans | Income producing | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	517,827		534,015
CRE | Loans Receivable | PCI loans | Income producing | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	6,164		9,960
CRE | Loans Receivable | PCI loans | Income producing | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	128,255		144,038
CRE | Loans Receivable | PCI loans | Construction
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	9,342	[1]	12,444	[1]
CRE | Loans Receivable | PCI loans | Construction | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	585		589
CRE | Loans Receivable | PCI loans | Construction | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,739		1,744
CRE | Loans Receivable | PCI loans | Construction | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	7,018		10,111
CRE | Loans Receivable | PCI loans | Land
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	12,792	[1]	16,840	[1]
CRE | Loans Receivable | PCI loans | Land | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	5,080		7,012
CRE | Loans Receivable | PCI loans | Land | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	5,433		5,391
CRE | Loans Receivable | PCI loans | Land | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	2,279		4,437
C&I | Loans Receivable
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	7,720,764	[1]	8,077,201	[1]
C&I | Loans Receivable | Commercial business
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	6,871,450	[1]	7,181,189	[1]
C&I | Loans Receivable | Trade finance
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	849,314	[1]	896,012	[1]
C&I | Loans Receivable | Non-PCI loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	7,643,239		7,987,581
Allowance for loan losses	(133,914)		(134,598)		(127,156)	(115,184)
C&I | Loans Receivable | Non-PCI loans | Commercial business
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	6,799,149		7,097,853
C&I | Loans Receivable | Non-PCI loans | Commercial business | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	6,573,081		6,836,914
C&I | Loans Receivable | Non-PCI loans | Commercial business | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	93,302		130,319
C&I | Loans Receivable | Non-PCI loans | Commercial business | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	132,286		130,032
C&I | Loans Receivable | Non-PCI loans | Commercial business | Doubtful
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	426		533
C&I | Loans Receivable | Non-PCI loans | Commercial business | Loss
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	54		55
C&I | Loans Receivable | Non-PCI loans | Trade finance
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	844,090		889,728
C&I | Loans Receivable | Non-PCI loans | Trade finance | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	788,864		845,889
C&I | Loans Receivable | Non-PCI loans | Trade finance | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	19,726		13,031
C&I | Loans Receivable | Non-PCI loans | Trade finance | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	35,500		30,808
C&I | Loans Receivable | PCI loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	77,525	[1]	89,620	[1]
C&I | Loans Receivable | PCI loans | Commercial business
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	72,301	[1]	83,336	[1]
C&I | Loans Receivable | PCI loans | Commercial business | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	62,858		70,586
C&I | Loans Receivable | PCI loans | Commercial business | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	997		1,103
C&I | Loans Receivable | PCI loans | Commercial business | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	8,446		11,647
C&I | Loans Receivable | PCI loans | Trade finance
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	5,224	[1]	6,284	[1]
C&I | Loans Receivable | PCI loans | Trade finance | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	3,535		4,620
C&I | Loans Receivable | PCI loans | Trade finance | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,689		1,664
Residential | Loans Receivable
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	4,997,219	[1]	5,316,689	[1]
Residential | Loans Receivable | Single-family
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	3,512,794	[1]	3,866,781	[1]
Residential | Loans Receivable | Multifamily
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,484,425	[1]	1,449,908	[1]
Residential | Loans Receivable | Non-PCI loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	4,539,134		4,831,279
Allowance for loan losses	(42,990)		(43,856)		(47,995)	(50,716)
Residential | Loans Receivable | Non-PCI loans | Single-family
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	3,298,775		3,647,262
Residential | Loans Receivable | Non-PCI loans | Single-family | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	3,277,085		3,627,491
Residential | Loans Receivable | Non-PCI loans | Single-family | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	3,595		3,143
Residential | Loans Receivable | Non-PCI loans | Single-family | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	18,095		16,628
Residential | Loans Receivable | Non-PCI loans | Multifamily
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,240,359		1,184,017
Residential | Loans Receivable | Non-PCI loans | Multifamily | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,162,798		1,095,982
Residential | Loans Receivable | Non-PCI loans | Multifamily | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	4,906		5,124
Residential | Loans Receivable | Non-PCI loans | Multifamily | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	72,655		82,911
Residential | Loans Receivable | PCI loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	458,085	[1]	485,410	[1]
Residential | Loans Receivable | PCI loans | Single-family
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	214,019	[1]	219,519	[1]
Residential | Loans Receivable | PCI loans | Single-family | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	208,238		213,829
Residential | Loans Receivable | PCI loans | Single-family | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	745		374
Residential | Loans Receivable | PCI loans | Single-family | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	5,036		5,316
Residential | Loans Receivable | PCI loans | Multifamily
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	244,066	[1]	265,891	[1]
Residential | Loans Receivable | PCI loans | Multifamily | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	211,060		230,049
Residential | Loans Receivable | PCI loans | Multifamily | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	33,006		35,842
Consumer | Loans Receivable
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,612,164	[1]	1,513,742	[1]
Consumer | Loans Receivable | Non-PCI loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,584,168		1,483,956
Allowance for loan losses	(10,451)		(10,248)		(11,156)	(11,352)
Consumer | Loans Receivable | Non-PCI loans | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,581,116		1,480,208
Consumer | Loans Receivable | Non-PCI loans | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	336		1,005
Consumer | Loans Receivable | Non-PCI loans | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	2,716		2,743
Consumer | Loans Receivable | PCI loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	27,996	[1]	29,786	[1]
Consumer | Loans Receivable | PCI loans | Pass/Watch
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	27,330		29,026
Consumer | Loans Receivable | PCI loans | Special Mention
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	115		116
Consumer | Loans Receivable | PCI loans | Substandard
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	$ 551		$ 644

[1] Loans net of ASC 310-30 discount.