NON-COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 4) (Non-covered loans, USD $) In Thousands, unless otherwise specified	Dec. 31, 2014 item		Dec. 31, 2013
Credit Quality Indicators
Number of grades in the risk rating system utilized by the company to rate credit risk of loans receivable	8
Total non-covered loans	$ 20,249,451	[1]	$ 15,678,317	[1]
Pass/Watch
Credit Quality Indicators
Total non-covered loans	19,453,512		14,991,479
Special Mention
Credit Quality Indicators
Total non-covered loans	208,175		197,284
Substandard
Credit Quality Indicators
Total non-covered loans	587,176		489,554
Doubtful
Credit Quality Indicators
Total non-covered loans	533
Loss
Credit Quality Indicators
Total non-covered loans	55
CRE
Credit Quality Indicators
Total non-covered loans	6,134,046		4,585,077
CRE | Construction
Credit Quality Indicators
Total non-covered loans	313,811		140,186
CRE | Construction | Pass/Watch
Credit Quality Indicators
Total non-covered loans	306,923		127,138
CRE | Construction | Special Mention
Credit Quality Indicators
Total non-covered loans			6,160
CRE | Construction | Substandard
Credit Quality Indicators
Total non-covered loans	6,888		6,888
CRE | Land
Credit Quality Indicators
Total non-covered loans	208,750		143,861
CRE | Land | Pass/Watch
Credit Quality Indicators
Total non-covered loans	179,319		116,000
CRE | Land | Special Mention
Credit Quality Indicators
Total non-covered loans	5,701		9,304
CRE | Land | Substandard
Credit Quality Indicators
Total non-covered loans	23,730		18,557
CRE | Income producing
Credit Quality Indicators
Total non-covered loans	5,611,485		4,301,030
CRE | Income producing | Pass/Watch
Credit Quality Indicators
Total non-covered loans	5,244,022		4,032,269
CRE | Income producing | Special Mention
Credit Quality Indicators
Total non-covered loans	54,431		56,752
CRE | Income producing | Substandard
Credit Quality Indicators
Total non-covered loans	313,032		212,009
C&I
Credit Quality Indicators
Total non-covered loans	7,838,094		5,360,193
C&I | Commercial business
Credit Quality Indicators
Total non-covered loans	7,031,350		4,637,056
C&I | Commercial business | Pass/Watch
Credit Quality Indicators
Total non-covered loans	6,783,051		4,400,847
C&I | Commercial business | Special Mention
Credit Quality Indicators
Total non-covered loans	128,578		92,315
C&I | Commercial business | Substandard
Credit Quality Indicators
Total non-covered loans	119,133		143,894
C&I | Commercial business | Doubtful
Credit Quality Indicators
Total non-covered loans	533
C&I | Commercial business | Loss
Credit Quality Indicators
Total non-covered loans	55
C&I | Trade finance
Credit Quality Indicators
Total non-covered loans	806,744		723,137
C&I | Trade finance | Pass/Watch
Credit Quality Indicators
Total non-covered loans	766,575		681,345
C&I | Trade finance | Special Mention
Credit Quality Indicators
Total non-covered loans	10,193		22,099
C&I | Trade finance | Substandard
Credit Quality Indicators
Total non-covered loans	29,976		19,693
Residential
Credit Quality Indicators
Total non-covered loans	4,820,668		4,185,309
Residential | Single-family
Credit Quality Indicators
Total non-covered loans	3,642,978		3,192,875
Residential | Single-family | Pass/Watch
Credit Quality Indicators
Total non-covered loans	3,624,097		3,167,337
Residential | Single-family | Special Mention
Credit Quality Indicators
Total non-covered loans	3,143		8,331
Residential | Single-family | Substandard
Credit Quality Indicators
Total non-covered loans	15,738		17,207
Residential | Multifamily
Credit Quality Indicators
Total non-covered loans	1,177,690		992,434
Residential | Multifamily | Pass/Watch
Credit Quality Indicators
Total non-covered loans	1,096,572		923,697
Residential | Multifamily | Special Mention
Credit Quality Indicators
Total non-covered loans	5,124		1,634
Residential | Multifamily | Substandard
Credit Quality Indicators
Total non-covered loans	75,994		67,103
Consumer
Credit Quality Indicators
Total non-covered loans	1,456,643		1,547,738
Consumer | Student loans
Credit Quality Indicators
Total non-covered loans			679,220
Consumer | Student loans | Pass/Watch
Credit Quality Indicators
Total non-covered loans			677,094
Consumer | Student loans | Special Mention
Credit Quality Indicators
Total non-covered loans			445
Consumer | Student loans | Substandard
Credit Quality Indicators
Total non-covered loans			1,681
Consumer | Other Consumer
Credit Quality Indicators
Total non-covered loans	1,456,643		868,518
Consumer | Other Consumer | Pass/Watch
Credit Quality Indicators
Total non-covered loans	1,452,953		865,752
Consumer | Other Consumer | Special Mention
Credit Quality Indicators
Total non-covered loans	1,005		244
Consumer | Other Consumer | Substandard
Credit Quality Indicators
Total non-covered loans	$ 2,685		$ 2,522

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