Revenue From Contracts With Customers - Contract Balances (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Receivables, which are included in "Other assets"	$ 1,406	$ 1,066
Contract liabilities, which are included in "Accrued interest payable and other liabilities"	$ 163	$ 229

Contract With Customer, Liabilities Reclassified to Other Assets

No definition available.

Name:	pacw_ContractWithCustomerLiabilitiesReclassifiedtoOtherAssets
Namespace Prefix:	pacw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration