ACQUISITIONS (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 First California Financial Group	May 31, 2013 First California Financial Group	Aug. 01, 2012 American Perspective	Apr. 03, 2012 Celtic	Jan. 03, 2012 PWE Finance
Assets Acquired:
Cash and due from banks				$ 6,124	$ 3,370	$ 3,435	$ 7,092
Interest-earning deposits in financial institutions				266,889	10,081
Investment securities available-for-sale				4,444	48,887
FHLB stock			9,500	9,518	1,412
Loans and leases				1,049,613	197,279	54,963	140,959
Other real estate owned				13,772	1,561
Premises and equipment, net	33,642	19,503		15,437
FDIC loss sharing asset				18,981
Cash surrender value of life insurance	80,592	68,326		13,265
Goodwill				129,517	15,047	6,645	19,033
Core deposit and customer relationship intangibles				7,927	1,924	1,300	1,700
Other intangible assets						670	1,420
Leases in process							19,162
Other assets				39,910	4,234	69	467
Total assets acquired				1,575,397	283,795	67,082	189,833
Liabilities Assumed:
Noninterest-bearing deposits				361,166	40,673
Interest-bearing deposits				739,713	178,891
Borrowings from parent							128,677
Other borrowings					5,315	46,804	15,839
Subordinated debentures	132,358	108,250	24,100	24,061
Discontinued operations	173,439			184,619
Accrued interest payable and other liabilities				19,492	840	2,278	10,317
Total liabilities assumed				1,329,051	225,719	49,082	154,833
Total consideration paid				246,346	58,076	18,000	35,000
Summary of consideration
Cash paid					58,076	18,000	35,000
PacWest common stock issued				242,268
Cancellation of FCAL common stock owned by PacWest				4,078
Total consideration paid				$ 246,346	$ 58,076	$ 18,000	$ 35,000