Subordinated Debentures (Details)			1 Months Ended		3 Months Ended	9 Months Ended
	Jul. 01, 2018 USD ($)	Nov. 01, 2017 USD ($) notes	Aug. 31, 2014 USD ($)	Mar. 31, 2004 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)	Apr. 01, 2017 USD ($)
PPBI Trust I
Subordinated Debentures
Floating Rate Trust Preferred Securities issue amount				$ 10,000,000
Notes
Subordinated Debentures
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
Subordinated Debentures
Effective rate (as a percent)					5.09%	5.09%
Subordinated Debentures | Mission Community Capital Trust I
Subordinated Debentures
Effective rate (as a percent)					5.29%	5.29%
Floating rate junior subordinated debt					$ 2,800,000	$ 2,800,000	$ 3,100,000
Purchase accounting fair value adjustments						$ 311,000
Subordinated Debentures | Santa Lucia Bancorp (CA) Capital Trust
Subordinated Debentures
Effective rate (as a percent)					3.82%	3.82%
Floating rate junior subordinated debt					$ 3,800,000	$ 3,800,000	5,200,000
Purchase accounting fair value adjustments						$ 1,300,000
Subordinated Debentures | Heritage Oaks Bancorp
Subordinated Debentures
Effective rate (as a percent)					4.06%	4.06%
Floating rate junior subordinated debt					$ 4,000,000	$ 4,000,000	$ 5,200,000
Purchase accounting fair value adjustments						1,300,000
Subordinated Debentures | Grandpoint Capital, Inc.
Subordinated Debentures
Effective rate (as a percent)	5.28%
Floating rate junior subordinated debt					4,900,000	$ 4,900,000
Purchase accounting fair value adjustments					$ 228,000
Debt assumed in acquisition	$ 5,200,000
Subordinated Debentures | LIBOR
Subordinated Debentures
Floating interest rate, basis points added to base rate (as a percent)						2.75%
Subordinated Debentures | LIBOR | Mission Community Capital Trust I
Subordinated Debentures
Floating interest rate, basis points added to base rate (as a percent)						2.95%
Subordinated Debentures | LIBOR | Santa Lucia Bancorp (CA) Capital Trust
Subordinated Debentures
Floating interest rate, basis points added to base rate (as a percent)						1.48%
Subordinated Debentures | LIBOR | Heritage Oaks Bancorp
Subordinated Debentures
Floating interest rate, basis points added to base rate (as a percent)						1.72%
Subordinated Debentures | LIBOR | Grandpoint Capital, Inc.
Subordinated Debentures
Floating interest rate, basis points added to base rate (as a percent)	2.95%
Subordinated Debentures | PPBI Trust I
Subordinated Debentures
Debt issued				$ 10,300,000.0
Minority interest purchased (as a percent)				3.00%
Amount of minority interest purchased				$ 310,000
Subordinated Notes 7.125% | Plaza Bancorp
Subordinated Debentures
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)		0.50%