SUBSEQUENT EVENTS (Details 2) (Subsequent event, Capital Source, USD $) In Thousands, unless otherwise specified	0 Months Ended
	Apr. 07, 2014
Assets Acquired:
Cash and due from banks	$ 768,553
Interest-earning deposits in financial institutions	60,612
Investment securities available-for-sale	429,771
Loans and leases	6,886,289
Other real estate owned	7,665
Goodwill and intangible assets	1,611,153
Deferred tax asset, net	235,026
Other assets	732,514
Total assets acquired	10,731,583
Liabilities Assumed:
Noninterest-bearing deposits	4,631
Interest-bearing deposits	6,236,419
Other borrowings	992,109
Subordinated debentures	300,918
Accrued interest payable and other liabilities	120,318
Total liabilities assumed	7,654,395
Total consideration paid	3,077,188
Summary of consideration:
Cash paid	483,118
PacWest common stock issued	2,594,070
Total consideration paid	3,077,188
Purchase Accounting Adjustment
Assets Acquired:
Loans and non-operating leases	(214,765)
Operating leases (included in Other assets)	(10,352)
Core deposit intangible	6,720
Investment in trust preferred securities	(3,352)
Liabilities Assumed:
Time deposit premium	(17,183)
Subordinated debentures	$ 111,235
Summary of consideration:
Estimated accretion/amortization period for loans and non-operating leases	60 months
Estimated accretion/amortization period for operating leases included in other assets	48 months
Estimated accretion/amortization period for core deposit intangible	84 months
Estimated accretion/amortization period for investment in trust preferred securities	280 months
Estimated accretion/amortization period for time deposit premium	60 months
Estimated accretion/amortization period minimum for subordinated debentures	280 months