ACQUISITIONS (Details) (USD $) In Thousands, unless otherwise specified						0 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	May 31, 2013 First California Financial Group
Assets Acquired:
Cash and due from banks						$ 6,124
Interest-earning deposits in financial institutions						266,889
Investment securities available-for-sale						4,444
FHLB stock						9,518
Loans and leases						1,049,613
Other real estate owned						13,772
Premises and equipment						15,322
FDIC loss sharing asset						17,241
Cash surrender value of life insurance						13,265
Goodwill	208,743	208,743	215,862	79,673	79,866	129,070
Core deposit and customer relationship intangibles						7,927
Other assets						47,671
Total assets acquired						1,580,856
Liabilities Assumed:
Noninterest-bearing deposits						361,166
Interest-bearing deposits						739,713
Subordinated debentures						24,061
Discontinued operations						184,619
Accrued interest payable and other liabilities						19,729
Total liabilities assumed						1,329,288
Total consideration paid						251,568
Summary of consideration:
PacWest common stock issued						242,268
Cancellation of FCAL common stock owned by PacWest						9,300
Total consideration paid						$ 251,568