SUBSEQUENT EVENTS (Details) (USD $)	3 Months Ended			9 Months Ended				0 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 First California Financial Group item	Aug. 01, 2012 Pacific Western Bank American Perspective Bank item	Nov. 05, 2012 Subsequent event	Nov. 06, 2012 Subsequent event First California Financial Group item
Subsequent events
Quarterly cash dividends declared per common share (in dollars per share)	$ 0.18	$ 0.18	$ 0.01	$ 0.54	$ 0.03			$ 0.25
Per share price of shares aqcuired									$ 8.00
Purchase price									$ 231,000,000
Approximate value of assets on a pro forma consolidated basis						$ 7,500,000,000
Number of branches						81	2
Number of independent directors of acquiree joining acquirer after acquisition									2
Percentage of outstanding shares, the holders of which have agreed to convert shares of preferred stock to common stock									100.00%
Percentage of outstanding shares, the holders of which have agreed to vote in favor of the merger									22.00%