Commitments and Contingencies (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitment To Contribute Capital to CRA Related Pool	$ 85,924	$ 55,500

Commitment To Contribute Capital to CRA Related Pool

No definition available.

Name:	pacw_CommitmentToContributeCapitaltoCRARelatedPool
Namespace Prefix:	pacw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant