NON-COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 5) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Age analysis of past Due non-covered loans and loans held for sale
Accruing loans 30 - 59 days past due	$ 24,154		$ 24,154		$ 34,414
Accruing loans 60 - 89 days past due	34,574		34,574		9,183
Total accruing past due loans	58,728		58,728		43,597
Nonaccrual loans less than 90 days past due	41,476		41,476		27,207
Nonaccrual loans 90 or more days past due	62,406		62,406		80,902
Total nonaccrual past due loans	103,882		103,882		108,109
Current loans	14,668,887		14,668,887		11,981,484
Total non-covered loans and loans held for sale, gross	14,831,497		14,831,497		12,133,190
Unearned fees, premiums and discounts, net	(26,165)		(26,165)		(19,301)
Recorded investment in non-covered loans and loans held for sale	14,805,332		14,805,332		12,113,889
Interest Income Foregone on Nonaccrual Loans
Interest income that would have been recognized had nonaccrual loans performed in accordance with their original terms	2,211	1,497	5,220	4,994
Less: Interest income recognized on nonaccrual loans on a cash basis	(809)	(633)	(1,724)	(1,526)
Interest income foregone on nonaccrual loans	1,402	864	3,496	3,468
Loans Held for Sale
Age analysis of past Due non-covered loans and loans held for sale
Current loans	232,309		232,309		174,317
Total non-covered loans and loans held for sale, gross	232,309		232,309		174,317
Residential | Single-family
Age analysis of past Due non-covered loans and loans held for sale
Accruing loans 30 - 59 days past due	7,857		7,857		4,820
Accruing loans 60 - 89 days past due	3,371		3,371		2,244
Total accruing past due loans	11,228		11,228		7,064
Nonaccrual loans less than 90 days past due	281		281		1,301
Nonaccrual loans 90 or more days past due	8,819		8,819		9,809
Total nonaccrual past due loans	9,100		9,100		11,110
Current loans	2,980,595		2,980,595		2,169,149
Total non-covered loans and loans held for sale, gross	3,000,923		3,000,923		2,187,323
Residential | Multifamily
Age analysis of past Due non-covered loans and loans held for sale
Accruing loans 30 - 59 days past due	5,503		5,503		7,127
Accruing loans 60 - 89 days past due	1,450		1,450		924
Total accruing past due loans	6,953		6,953		8,051
Nonaccrual loans less than 90 days past due	20,642		20,642		6,788
Nonaccrual loans 90 or more days past due	8,479		8,479		11,052
Total nonaccrual past due loans	29,121		29,121		17,840
Current loans	940,773		940,773		874,817
Total non-covered loans and loans held for sale, gross	976,847		976,847		900,708
Commercial Real Estate ("CRE") | Income producing
Age analysis of past Due non-covered loans and loans held for sale
Accruing loans 30 - 59 days past due	7,868		7,868		18,118
Accruing loans 60 - 89 days past due	25,281		25,281		4,731
Total accruing past due loans	33,149		33,149		22,849
Nonaccrual loans less than 90 days past due	13,175		13,175		9,485
Nonaccrual loans 90 or more days past due	16,976		16,976		8,354
Total nonaccrual past due loans	30,151		30,151		17,839
Current loans	4,065,194		4,065,194		3,603,347
Total non-covered loans and loans held for sale, gross	4,128,494		4,128,494		3,644,035
Commercial Real Estate ("CRE") | Construction
Age analysis of past Due non-covered loans and loans held for sale
Nonaccrual loans 90 or more days past due	6,888		6,888		27,039
Total nonaccrual past due loans	6,888		6,888		27,039
Current loans	114,709		114,709		94,550
Total non-covered loans and loans held for sale, gross	121,597		121,597		121,589
Commercial Real Estate ("CRE") | Land
Age analysis of past Due non-covered loans and loans held for sale
Accruing loans 30 - 59 days past due	92		92
Accruing loans 60 - 89 days past due	555		555
Total accruing past due loans	647		647
Nonaccrual loans less than 90 days past due	756		756		637
Nonaccrual loans 90 or more days past due	3,301		3,301		3,984
Total nonaccrual past due loans	4,057		4,057		4,621
Current loans	107,817		107,817		124,450
Total non-covered loans and loans held for sale, gross	112,521		112,521		129,071
Commercial and Industrial ("C&I") | Commercial Business
Age analysis of past Due non-covered loans and loans held for sale
Accruing loans 30 - 59 days past due	1,340		1,340		3,293
Accruing loans 60 - 89 days past due	3,007		3,007		316
Total accruing past due loans	4,347		4,347		3,609
Nonaccrual loans less than 90 days past due	6,622		6,622		8,068
Nonaccrual loans 90 or more days past due	15,305		15,305		14,740
Total nonaccrual past due loans	21,927		21,927		22,808
Current loans	4,173,412		4,173,412		3,542,971
Total non-covered loans and loans held for sale, gross	4,199,686		4,199,686		3,569,388
Commercial and Industrial ("C&I") | Trade finance
Age analysis of past Due non-covered loans and loans held for sale
Accruing loans 30 - 59 days past due					500
Accruing loans 60 - 89 days past due	84		84
Total accruing past due loans	84		84		500
Nonaccrual loans less than 90 days past due					429
Nonaccrual loans 90 or more days past due	863		863		2,003
Total nonaccrual past due loans	863		863		2,432
Current loans	680,735		680,735		658,945
Total non-covered loans and loans held for sale, gross	681,682		681,682		661,877
Consumer | Student loans
Age analysis of past Due non-covered loans and loans held for sale
Accruing loans 30 - 59 days past due	1,307		1,307		71
Accruing loans 60 - 89 days past due	171		171
Total accruing past due loans	1,478		1,478		71
Nonaccrual loans 90 or more days past due	1,017		1,017
Total nonaccrual past due loans	1,017		1,017
Current loans	699,796		699,796		475,728
Total non-covered loans and loans held for sale, gross	702,291		702,291		475,799
Consumer | Other Consumer
Age analysis of past Due non-covered loans and loans held for sale
Accruing loans 30 - 59 days past due	187		187		485
Accruing loans 60 - 89 days past due	655		655		968
Total accruing past due loans	842		842		1,453
Nonaccrual loans less than 90 days past due					499
Nonaccrual loans 90 or more days past due	758		758		3,921
Total nonaccrual past due loans	758		758		4,420
Current loans	673,547		673,547		263,210
Total non-covered loans and loans held for sale, gross	$ 675,147		$ 675,147		$ 269,083