ACQUISITIONS (Details 2) (USD $)	3 Months Ended					12 Months Ended					12 Months Ended							0 Months Ended			12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 29, 2012	Mar. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Los Padres Bank item	Aug. 20, 2010 Los Padres Bank	Dec. 31, 2012 Los Padres Bank California item	Dec. 31, 2012 Los Padres Bank Ventura County item	Dec. 31, 2012 Los Padres Bank Santa Barbara County item	Dec. 31, 2012 Los Padres Bank San Luis Obispo County item	Dec. 31, 2012 Los Padres Bank Arizona item	Dec. 31, 2012 First California item	Nov. 06, 2012 First California item	Nov. 06, 2012 First California Minimum	Nov. 06, 2012 First California Maximum	Sep. 30, 2012 First California Los Angeles, Orange, Riverside, San Bernardino, San Diego, San Luis Obispo and Ventura Counties item	Dec. 31, 2012 Pacific Western Bank Los Padres Bank	Dec. 31, 2011 Pacific Western Bank Los Padres Bank	Dec. 31, 2012 Pacific Western Bank Los Padres Bank Single family covered assets	Dec. 31, 2012 Pacific Western Bank Los Padres Bank Commercial (non-single family) covered assets
Federally assisted acquisition of Los Padres Bank and Affinity Bank
Percentage of losses absorbed by FDIC as per loss sharing agreement									80.00%												80.00%
Percentage of loss recoveries reimbursed to FDIC as per loss sharing agreement									80.00%												80.00%
Period of loss sharing provisions in effect																							10 years	5 years
Period of loss recovery provisions in effect																							8 years	10 years
Gross losses for covered assets						$ 6,169,000	$ 15,377,000														$ 65,000,000
Number of operating branches									14		11	3	4	4	3					15
Reduction in goodwill due to the resolution of a matter with the FDIC																						8,200,000
Number of former branches of acquiree now operated by the entity									6
Cash payment for resolution of goodwill matter with FDIC							7,636,000															8,200,000
Remaining merger-related liability	1,400,000					1,400,000
Amount of expenses incurred related to acquisition	1,092,000	2,101,000	871,000	25,000	600,000	4,089,000	600,000	732,000
Per share price of shares aqcuired																	$ 8.00
Aggregate consideration																	231,000,000
Measuring period for determining weighted average price per share for fluctuating shares						20 days
Threshold average price for determining fluctuating shares (in dollars per share)																		$ 20.00	$ 27.00
Threshold average price for determining fixed shares (in dollars per share)																		$ 27.00	$ 20.00
Closing stock price (in dollars per share)	$ 24.77					$ 24.77											$ 26.64
Number of shares of entity receivable by stockholders of acquiree for each share of acquiree																	0.3003
Pro forma aggregate percentage of stockholders of acquiree in common stock of combined company																	19.30%
Assets										824,083,000						1,900,000,000
Pro forma consolidated assets																$ 7,400,000,000
Pro forma consolidated branches																82
Number of independent directors of acquiree who will join the entity's board of directors upon completion of acquisition																	2