Fair Value Election, Credit Link, Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Other Borrowings, Fair Value Disclosure	$ 128,375	$ 132,030
Borrowings - Credit-Link Notes	129,500
Aggregate Unpaid Principal Balance in Excess of (Less Than) Fair Value	$ 1,087	$ (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