SUBSEQUENT EVENTS (Details) (USD $)	3 Months Ended			6 Months Ended				1 Months Ended		1 Months Ended	6 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Jun. 30, 2012 American Perspective Bank item	Aug. 31, 2012 Subsequent event	Aug. 01, 2012 Subsequent event American Perspective Bank	Jul. 31, 2012 Subsequent event Pacific Western Bank item	Jun. 30, 2012 Subsequent event Pacific Western Bank
Subsequent events
Number of branches to be sold to Opus Bank										10
Blended deposit premium applied to deposit balances transferred (as a percent)										2.50%
Deposits of the offices to be sold											$ 145,000,000
Annual cost savings, representing noninterest expense less noninterest income, after tax											2,000,000
Amount paid in cash for acquisition									58,100,000
Price per share for each share of common stock									$ 13.00
Assets	$ 5,321,622,000		$ 5,394,725,000	$ 5,321,622,000	$ 5,394,725,000	$ 5,528,237,000	$ 271,000,000
Number of branches							2
Quarterly cash dividends declared per common share (in dollars per share)	$ 0.18	$ 0.18	$ 0.01	$ 0.36	$ 0.02			$ 0.18