Note 2 - Condensed Consolidated Financial Statements (Details Textual) xbrli-pure in Thousands	Jun. 30, 2017
Customer Concentration Risk [Member] \| Sales Revenue, Net [Member]
Number of Major Customers	0

Represents the number of major customers accounting for 10% or more of the specified concentration risk benchmark, which includes, but not limited to, sales revenue, accounts receivable, etc.

No definition available.

Name:	plbc_NumberOfMajorCustomers
Namespace Prefix:	plbc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant