Subordinated Debentures (Details)			1 Months Ended	12 Months Ended
	Nov. 01, 2017 USD ($) notes	Mar. 25, 2004 USD ($)	Aug. 31, 2014 USD ($)	Dec. 31, 2017 USD ($)	Apr. 01, 2017 USD ($)	Dec. 31, 2016
PPBI Trust I
Debt Instrument [Line Items]
Floating Rate Trust Preferred Securities issue amount		$ 10,000,000
Subordinated Notes Due 2024
Debt Instrument [Line Items]
Debt issued			$ 60,000,000
Fixed interest rate (as a percent)			5.75%
Contribution of net proceeds from the Private Placement to the Bank to support general corporate purposes			$ 50,000,000
Subordinated Debentures
Debt Instrument [Line Items]
Floating interest rate, base rate				3-month LIBOR
Floating interest rate, basis points added to base rate (as a percent)				2.75%
Effective rate (as a percent)				4.11%		3.63%
Subordinated Debentures | Mission Community Capital Trust I
Debt Instrument [Line Items]
Effective rate (as a percent)				4.31%
Purchase accounting fair value adjustments				$ 327,000
Debt assumed in acquisition				$ 2,800,000	$ 3,100,000
Subordinated Debentures | Santa Lucia Bancorp (CA) Capital Trust
Debt Instrument [Line Items]
Effective rate (as a percent)				2.84%
Purchase accounting fair value adjustments				$ 1,400,000
Debt assumed in acquisition				$ 3,800,000	5,200,000
Subordinated Debentures | LIBOR | Mission Community Capital Trust I
Debt Instrument [Line Items]
Floating interest rate, basis points added to base rate (as a percent)				2.95%
Subordinated Debentures | LIBOR | Santa Lucia Bancorp (CA) Capital Trust
Debt Instrument [Line Items]
Floating interest rate, basis points added to base rate (as a percent)				1.48%
Subordinated Debentures | Heritage Oaks Bank
Debt Instrument [Line Items]
Effective rate (as a percent)				3.06%
Purchase accounting fair value adjustments				$ 1,300,000
Debt assumed in acquisition				$ 3,900,000	$ 5,200,000
Subordinated Debentures | Heritage Oaks Bank | LIBOR
Debt Instrument [Line Items]
Floating interest rate, basis points added to base rate (as a percent)				1.72%
Subordinated Debentures | PPBI Trust I
Debt Instrument [Line Items]
Debt issued		$ 10,310,000
Minority interest purchased (as a percent)		3.00%
Amount of minority interest purchased		$ 310,000
Subordinated Notes 7.125% | Plaza Bancorp
Debt Instrument [Line Items]
Fixed interest rate (as a percent)	7.125%
Number of subordinated notes assumed | notes	3
Debt assumed in acquisition	$ 25,000,000
Redemption price (as a percent)	103.00%
Redemption price, subsequent reduction (as a percent)	50.00%