Subordinated Debentures - Narrative (Details)			1 Months Ended		3 Months Ended		12 Months Ended
	Jul. 07, 2021 USD ($)	Apr. 15, 2021 USD ($)	Jun. 30, 2020 USD ($)	May 31, 2019 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($) loan	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jul. 31, 2021 USD ($)	Jul. 01, 2021 USD ($)	Aug. 31, 2014 USD ($)
Debt Instrument [Line Items]
Subordinated debentures							$ 330,567,000	$ 501,511,000
Weighted average interest rate at year-end							5.33%	5.38%
decrease to carrying value of subordinated debt							$ 170,900,000	$ 170,400,000
Face amount of debt instrument							335,000,000
Gain (loss) on debt extinguishment							$ (180,000)	0	$ 0
Subordinated notes
Debt Instrument [Line Items]
Number of subordinated debt instruments | loan							3
Subordinated debentures							$ 330,567,000	493,410,000
Face amount of debt instrument						$ 25,000,000	335,000,000
Redemption price (as a percent)		103.00%
Redemption amount		$ 25,800,000
Gain (loss) on debt extinguishment		(647,000)
Purchase accounting adjustments		$ 103,000
Reduction in Tier 2 capital					$ (146,000,000)	$ (20,000,000)
Redeemed amount of debt instrument					$ 145,400,000
Subordinated notes | Opus
Debt Instrument [Line Items]
Face amount of debt instrument											$ 135,000,000
Fixed interest rate (as a percent)											5.50%
Subordinated notes | Subordinated notes due 2024, 5.75% per annum
Debt Instrument [Line Items]
Subordinated debentures							59,671,000	59,552,000
Face amount of debt instrument							$ 60,000,000					$ 60,000,000
Fixed interest rate (as a percent)							5.75%					5.75%
Unamortized debt issuance costs							$ 329,000
Effective rate (as a percent)							5.75%
Subordinated notes | Subordinated notes due 2029, 4.875% per annum until May 15, 2024, 3-month LIBOR +4.9% thereafter
Debt Instrument [Line Items]
Subordinated debentures							$ 123,132,000	122,877,000
Face amount of debt instrument				$ 125,000,000			$ 125,000,000
Fixed interest rate (as a percent)				4.875%			4.875%
Unamortized debt issuance costs							$ 1,900,000
Public offering price				100.00%
Effective rate (as a percent)							4.875%
Subordinated notes | Subordinated notes due 2029, 4.875% per annum until May 15, 2024, 3-month LIBOR +4.9% thereafter | LIBOR
Debt Instrument [Line Items]
Floating interest rate, basis points added to base rate (as a percent)				2.50%			4.90%
Subordinated notes | Subordinated notes due 2030, 5.375% per annum until June 15, 2025, 3-month SOFR +5.17% thereafter
Debt Instrument [Line Items]
Subordinated debentures							$ 147,764,000	147,501,000
Face amount of debt instrument			$ 150,000,000				$ 150,000,000
Fixed interest rate (as a percent)							5.375%
Unamortized debt issuance costs							$ 2,200,000
Effective rate (as a percent)							5.375%
Offering price, percentage of aggregate principal amount			100.00%
Subordinated notes | Subordinated notes due 2030, 5.375% per annum until June 15, 2025, 3-month SOFR +5.17% thereafter | SOFR
Debt Instrument [Line Items]
Floating interest rate, basis points added to base rate (as a percent)			5.17%				0.0517%
Subordinated debt
Debt Instrument [Line Items]
Subordinated debentures							$ 0	$ 8,101,000
Face amount of debt instrument							$ 0
Subordinated debt | Heritage Oaks Bank
Debt Instrument [Line Items]
Face amount of debt instrument											$ 5,200,000
Fixed interest rate (as a percent)											1.92%
Redeemed amount of debt instrument										$ 5,200,000
Subordinated debt | Santa Lucia Bancorp (CA) Capital Trust
Debt Instrument [Line Items]
Face amount of debt instrument	$ 5,200,000
Fixed interest rate (as a percent)	1.66%
Redeemed amount of debt instrument										$ 5,200,000
Subordinated debt | Subordinated notes due 2024, 5.75% per annum
Debt Instrument [Line Items]
Percentage of Notes I qualified as Tier 2 Capital as remaining maturity is less than four years							40.00%
Subordinated and Junior Subordinated Debt
Debt Instrument [Line Items]
Redemption amount	$ 149,200,000
Gain (loss) on debt extinguishment	$ 970,000