COVERED ASSETS AND FDIC INDEMNIFICATION ASSET (Details 3) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Allowance for loan losses disclosures
Allowance on covered loans	$ 9,629,000		$ 9,629,000		$ 5,153,000
Provision for covered loans	723,000	(1,095,000)	5,812,000	526,000
Percentage of allowance allocated to covered loans	4.00%		4.00%
United Commercial Bank (UCB)
Allowance for loan losses disclosures
Period before which the acquisition was made			3 years 6 months
Washington First International Bank (WFIB)
Allowance for loan losses disclosures
Period before which the acquisition was made			3 years
Covered loans accounted for under ASC 310-30
Allowance for loan losses disclosures
Provision for covered loans			2,500,000
Covered loans accounted for under ASC 310-30 | Commercial Real Estate ("CRE")
Allowance for loan losses disclosures
Allowance on covered loans	2,500,000		2,500,000
Specific covered loans outside of the scope of ASC 310-30
Allowance for loan losses disclosures
Provision for covered loans	186,000	(1,100,000)	3,300,000	526,000
Additional advances under shared-loss agreements	358,800,000		358,800,000		431,700,000
Charge-offs	1,200,000	0	1,300,000	0
Allowance allocated to additional advances	7,100,000		7,100,000		5,200,000
Percentage of allowance allocated to covered loans	2.90%		2.90%		2.20%
Specific covered loans outside of the scope of ASC 310-30 | Commercial and Industrial ("C&I")
Allowance for loan losses disclosures
Additional advances under shared-loss agreements	248,300,000		248,300,000		302,300,000
Allowance allocated to additional advances	4,100,000		4,100,000		2,400,000
Specific covered loans outside of the scope of ASC 310-30 | Commercial Real Estate ("CRE")
Allowance for loan losses disclosures
Additional advances under shared-loss agreements	67,300,000		67,300,000		83,400,000
Allowance allocated to additional advances	2,400,000		2,400,000		2,500,000
Specific covered loans outside of the scope of ASC 310-30 | Consumer
Allowance for loan losses disclosures
Additional advances under shared-loss agreements	31,900,000		31,900,000		34,500,000
Allowance allocated to additional advances	407,000		407,000		194,000
Specific covered loans outside of the scope of ASC 310-30 | Residential
Allowance for loan losses disclosures
Additional advances under shared-loss agreements	11,300,000		11,300,000		11,500,000
Allowance allocated to additional advances	$ 174,000		$ 174,000		$ 87,000