Subordinated Debentures (Details)		1 Months Ended		3 Months Ended
	Nov. 01, 2017 USD ($) note	Aug. 31, 2014 USD ($)	Mar. 31, 2004 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jul. 01, 2018 USD ($)	Apr. 01, 2017 USD ($)
Subordinated Debentures
Subordinated debentures				$ 110,381,000	$ 110,313,000
PPBI Trust I
Subordinated Debentures
Floating Rate Trust Preferred Securities issue amount			$ 10,000,000.0
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				59,300,000
Unamortized debt issuance cost				$ 658,000
Subordinated Debentures
Subordinated Debentures
Effective rate (as a percent)				5.54%
Subordinated Debentures | Mission Community Capital Trust I
Subordinated Debentures
Effective rate (as a percent)				5.74%
Floating rate junior subordinated debt				$ 2,800,000			$ 3,100,000
Purchase accounting fair value adjustments				$ 301,000
Subordinated Debentures | Santa Lucia Bancorp (CA) Capital Trust
Subordinated Debentures
Effective rate (as a percent)				4.27%
Floating rate junior subordinated debt				$ 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)				4.52%
Floating rate junior subordinated debt				$ 4,000,000.0			$ 5,200,000
Purchase accounting fair value adjustments				1,200,000
Subordinated Debentures | Plaza Bancorp
Subordinated Debentures
Floating rate junior subordinated debt				25,200,000
Purchase accounting fair value adjustments				$ 151,000
Subordinated Debentures | Grandpoint Capital, Inc.
Subordinated Debentures
Effective rate (as a percent)				5.56%
Floating rate junior subordinated debt				$ 4,900,000
Purchase accounting fair value adjustments				$ (221,000)
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
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 | note	3
Debt assumed in acquisition	$ 25,000,000.0
Redemption price (as a percent)	103.00%
Redemption price, subsequent reduction (as a percent)	0.50%