Fair Value Election, Credit Link, Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Other Borrowings, Fair Value Disclosure	$ 123,782	$ 132,030
Borrowings - Credit-Link Notes	126,100
Aggregate Unpaid Principal Balance in Excess of (Less Than) Fair Value	$ 2,300	$ (911)

Aggregate Unpaid Principal Balance in Excess of (Less Than) Fair Value

No definition available.

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