ACQUISITIONS (Details 2) (USD $)				0 Months Ended	3 Months Ended	9 Months Ended	0 Months Ended					0 Months Ended			0 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	May 31, 2013 First California Financial Group	Sep. 30, 2013 First California Financial Group	Sep. 30, 2013 First California Financial Group	May 31, 2013 First California Financial Group Maximum	May 31, 2013 First California Financial Group Pacific Western item	May 31, 2013 First California Financial Group FCB item	Aug. 03, 2012 APB	Aug. 01, 2012 APB	Aug. 03, 2012 APB Pacific Western item	Apr. 03, 2012 Celtic	Apr. 03, 2012 Celtic Pacific Western Maximum	Jan. 03, 2012 Pacific Western Equipment Finance
Acquisitions
Number of shares of entity receivable by stockholders of acquiree for each share of acquiree				0.2966
Measuring period for determining weighted average price per share for fluctuating shares				20 days
Issuance of common stock (in shares)				8,400,000
Common stock of acquiree cancelled in merger (in shares)				1,000,000
Closing price of common stock (in dollars per share)				$ 28.83
Total consideration paid				$ 251,568,000						$ 58,076,000			$ 18,000,000		$ 35,000,000
Number of operating branches									15			2
Number of operating branches which overlapped with existing branches									8
Number of operating branches closed as part of the integration and consolidation plan								2	6
Number of locations added to branch network as a result of integration and consolidation plan								7
Period for adjustment of fair values preliminary estimates							1 year
Goodwill	215,862,000	79,866,000	79,592,000	136,189,000							15,047,000		6,645,000		19,033,000
Threshold limit of asset-based loans														5,000,000
Non-taxable gain in earnings on previously-held equity interest					5,200,000	5,200,000
Available for sale equity securities acquired (in shares)					1,094,000	1,094,000
Cost of available for sale securities acquired					4,100,000	4,100,000
Unrealized gain included in stockholders' equity					$ 5,200,000