COVERED ASSETS AND FDIC INDEMNIFICATION ASSET (Details 6) (USD $)	12 Months Ended					0 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Nov. 06, 2009
Covered Nonperforming Assets
Other real estate owned covered, net	$ 4,499,000		$ 21,373,000
Number of past due days for the loans receivable to be placed on nonaccrual status	90 days
Covered assets - other disclosures
Interest income related to loans removed	87,500,000		168,100,000
Covered Loans
Covered Nonperforming Assets
Covered nonaccrual loans	62,665,000	[1],[2],[3]	126,895,000	[1],[2],[3]
Other real estate owned covered, net	4,499,000		21,373,000
Total covered nonperforming assets	67,164,000		148,268,000
Percentage of any reimbursable expense recorded as interest income under ASC 310-30	80.00%
Covered loans past due 90 days or more but not on nonaccrual	0		0
Number of past due days for the loans receivable to be placed on nonaccrual status	90 days		90 days
Covered TDR activity
Beginning balance	116,007,000		157,736,000
Additions	1,264,000		35,865,000
Transfers to covered OREO	(1,230,000)
Charge-offs	(1,504,000)		(10,167,000)
Paydowns/Reductions	(71,810,000)		(67,427,000)
Ending Balance	42,727,000		116,007,000		157,736,000
Changes in the accretable yield for the covered loans
Beginning balance	461,545,000		556,986,000		785,165,000
Accretion	(214,209,000)		(347,010,000)		(382,132,000)
Changes in expected cash flows	59,188,000		251,569,000		153,953,000
Ending Balance	306,524,000		461,545,000		556,986,000
Covered assets - other disclosures
Amount reclassified from nonaccretable yield to accretable yield due to changes in loss rate assumptions	52,500,000		190,300,000
Amount of loans removed from the covered loans accounted for under ASC 310-30, excluding scheduled principal payments	647,000,000		739,300,000		924,700,000
Interest income related to loans removed	87,500,000		168,100,000		124,700,000
Covered Loans | Covered Advances
Covered Nonperforming Assets
Covered nonaccrual loans	10,100,000		17,700,000
Covered Loans | PCI Covered Loans
Covered Nonperforming Assets
Covered nonaccrual loans	52,600,000		109,200,000
Covered Loans | Covered OREO Properties
Covered Nonperforming Assets
Covered OREO balances	4,500,000
Number of covered OREO properties added during the period	17
Aggregate carrying value of covered OREO properties added during the period	28,000,000		21,400,000
Net valuation adjustments included in aggregate carrying value on covered OREO properties	1,300,000		2,400,000
Number of covered OREO properties sold during the period	29
Total proceeds value of covered OREO properties sold during the period	52,100,000
Total net gains (losses) on covered OREO properties sold during the period	$ 8,500,000
Covered Loans | United Commercial Bank (UCB)
Credit Risk and Concentrations
Percentage of the entity's total covered loans acquired from a specific counterparty	93.00%
Number of general geographic regions	3
Covered Loans | United Commercial Bank (UCB) | Covered loans acquired from specific acquiree | Geographic Concentration | California | PCI Covered Loans
Credit Risk and Concentrations
Percent of total						64.00%
Covered Loans | United Commercial Bank (UCB) | Covered loans acquired from specific acquiree | Geographic Concentration | New York | PCI Covered Loans
Credit Risk and Concentrations
Percent of total						11.00%
Covered Loans | United Commercial Bank (UCB) | Covered loans acquired from specific acquiree | Geographic Concentration | Hong Kong | PCI Covered Loans
Credit Risk and Concentrations
Percent of total						10.00%

[1] Covered nonaccrual loans include loans that meet the criteria for nonaccrual but have a yield accreted through interest income under ASC 310-30.All losses on covered loans are 80% reimbursed by the FDIC.

[2] Net of discount.

[3] Includes $10.1 million and $17.7 million of covered advances as of December 31, 2014 and December 31, 2013, respectively; and $52.6 million and $109.2 million of PCI loans as of December 31, 2014 and December 31, 2013, respectively.