Subsequent Events (Details) $ / shares in Units, $ in Thousands					3 Months Ended			6 Months Ended
		Jul. 27, 2021 $ / shares	Jul. 01, 2021 USD ($)	Apr. 15, 2021 USD ($)	Jun. 30, 2021 USD ($) $ / shares	Mar. 31, 2021 USD ($)	Jun. 30, 2020 USD ($) $ / shares	Jun. 30, 2021 USD ($) $ / shares	Jun. 30, 2020 USD ($) $ / shares	Jul. 16, 2021 office
Subsequent Event [Line Items]
Cash dividends declared (in dollars per share) | $ / shares					$ 0.33		$ 0.25	$ 0.63	$ 0.50
Loss on early debt extinguishment								$ 1,150	$ 0
Unrealized gain (loss) on securities available-for-sale arising during the period, net of income taxes	[1]				$ 45,343	$ (72,592)	$ 13,800	$ (27,249)	$ 42,220
Subordinated notes
Subsequent Event [Line Items]
Redemption amount				$ 25,800
Loss on early debt extinguishment				$ (647)
Subsequent Event
Subsequent Event [Line Items]
Cash dividends declared (in dollars per share) | $ / shares		$ 0.33
Number of bank branch offices consolidated | office										2
Number of bank branch offices operated | office										63
Subsequent Event | Municipal bonds
Subsequent Event [Line Items]
Available-for-sale securities transferred to held-to-maturity			$ 157,700
Unrealized gain (loss) on securities available-for-sale arising during the period, net of income taxes			3,200
Gain (loss) recorded on transfer of available-for-sale to held-to-maturity securities			0
Subsequent Event | Subordinated and Junior Subordinated Debt
Subsequent Event [Line Items]
Redemption amount			149,200
Loss on early debt extinguishment			(970)
Subsequent Event | Opus | Subordinated notes
Subsequent Event [Line Items]
Redemption amount			135,000
Subsequent Event | Heritage Oaks Capital Trust II | Subordinated debt
Subsequent Event [Line Items]
Redemption amount			5,200
Subsequent Event | Santa Lucia Bancorp (CA) Capital Trust | Subordinated debt
Subsequent Event [Line Items]
Redemption amount			$ 5,200

[1] Income tax expense (benefit) on the unrealized gain (loss) on securities was $18.2 million for the three months ended June 30, 2021, $(29.1) million for the three months ended March 31, 2021, $5.5 million for the three months ended June 30, 2020, $(10.9) million for the six months ended June 30, 2021, and $17.0 million for the six months ended June 30, 2020.