NON-COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 5) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Age analysis of past Due non-covered loans and loans held for sale
Accruing loans 30 - 59 days past due	$ 41,508		$ 34,414
Accruing loans 60 - 89 days past due	5,087		9,183
Total accruing past due loans	46,595		43,597
Nonaccrual loans less than 90 days past due	28,707		27,207
Nonaccrual loans 90 or more days past due	98,456		80,902
Total nonaccrual past due loans	127,163		108,109
Current loans	12,427,905		11,981,484
Total non-covered loans and loans held for sale, gross	12,601,663		12,133,190
Unearned fees, premiums and discounts, net	(26,329)		(19,301)
Recorded investment in non-covered loans and loans held for sale	12,575,334		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	1,656	1,730
Less: Interest income recognized on nonaccrual loans on a cash basis	(606)	(701)
Interest income foregone on nonaccrual loans	1,050	1,029
Loans Held for Sale
Age analysis of past Due non-covered loans and loans held for sale
Nonaccrual loans 90 or more days past due	25,837
Total nonaccrual past due loans	25,837
Current loans	200,798		174,317
Total non-covered loans and loans held for sale, gross	226,635		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	5,939		4,820
Accruing loans 60 - 89 days past due	1,861		2,244
Total accruing past due loans	7,800		7,064
Nonaccrual loans less than 90 days past due	497		1,301
Nonaccrual loans 90 or more days past due	9,097		9,809
Total nonaccrual past due loans	9,594		11,110
Current loans	2,317,519		2,169,149
Total non-covered loans and loans held for sale, gross	2,334,913		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	4,306		7,127
Accruing loans 60 - 89 days past due	238		924
Total accruing past due loans	4,544		8,051
Nonaccrual loans less than 90 days past due	9,593		6,788
Nonaccrual loans 90 or more days past due	4,961		11,052
Total nonaccrual past due loans	14,554		17,840
Current loans	900,122		874,817
Total non-covered loans and loans held for sale, gross	919,220		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	16,489		18,118
Accruing loans 60 - 89 days past due	2,689		4,731
Total accruing past due loans	19,178		22,849
Nonaccrual loans less than 90 days past due	10,533		9,485
Nonaccrual loans 90 or more days past due	8,718		8,354
Total nonaccrual past due loans	19,251		17,839
Current loans	3,716,005		3,603,347
Total non-covered loans and loans held for sale, gross	3,754,434		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	27,044		27,039
Total nonaccrual past due loans	27,044		27,039
Current loans	102,837		94,550
Total non-covered loans and loans held for sale, gross	129,881		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	11,770
Total accruing past due loans	11,770
Nonaccrual loans less than 90 days past due	305		637
Nonaccrual loans 90 or more days past due	4,321		3,984
Total nonaccrual past due loans	4,626		4,621
Current loans	95,601		124,450
Total non-covered loans and loans held for sale, gross	111,997		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	2,333		3,293
Accruing loans 60 - 89 days past due	229		316
Total accruing past due loans	2,562		3,609
Nonaccrual loans less than 90 days past due	7,406		8,068
Nonaccrual loans 90 or more days past due	14,714		14,740
Total nonaccrual past due loans	22,120		22,808
Current loans	3,563,546		3,542,971
Total non-covered loans and loans held for sale, gross	3,588,228		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
Total accruing past due loans			500
Nonaccrual loans less than 90 days past due	373		429
Nonaccrual loans 90 or more days past due	2,419		2,003
Total nonaccrual past due loans	2,792		2,432
Current loans	689,769		658,945
Total non-covered loans and loans held for sale, gross	692,561		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	295		71
Accruing loans 60 - 89 days past due	67
Total accruing past due loans	362		71
Current loans	562,457		475,728
Total non-covered loans and loans held for sale, gross	562,819		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	376		485
Accruing loans 60 - 89 days past due	3		968
Total accruing past due loans	379		1,453
Nonaccrual loans less than 90 days past due			499
Nonaccrual loans 90 or more days past due	1,345		3,921
Total nonaccrual past due loans	1,345		4,420
Current loans	279,251		263,210
Total non-covered loans and loans held for sale, gross	$ 280,975		$ 269,083