Document and Entity Information (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Mar. 02, 2012	Jun. 30, 2011
Document and Entity Information
Entity Registrant Name	PACWEST BANCORP
Entity Central Index Key	0001102112
Document Type	10-K
Document Period End Date	Dec. 31, 2011
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 615
Entity Common Stock, Shares Outstanding		35,680,378
Entity Common Stock, Shares Outstanding Unvested Restricted		1,617,760
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	FY