Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($)			1 Months Ended
	May 04, 2018	Apr. 06, 2018	Oct. 31, 2019	May 31, 2018	Apr. 30, 2018	Aug. 31, 2015	Nov. 30, 2014	Dec. 31, 2019	Dec. 31, 2018
United American Bank
Other Intangible Assets
Accumulated amortization								$ 1,788,000	$ 756,000
Useful life, amortization period	3 years
United American Bank | Core deposit
Other Intangible Assets
Intangible assets acquired				$ 5,723,000
Useful life, amortization period				10 years
United American Bank | Below or Above market-value lease
Other Intangible Assets
Intangible assets acquired				$ 660,000
Useful life, amortization period				3 years
Tri Valley Bank
Other Intangible Assets
Accumulated amortization								480,000	222,000
Useful life, amortization period		11 years
Tri Valley Bank | Core deposit
Other Intangible Assets
Intangible assets acquired					$ 1,768,000
Useful life, amortization period					10 years
Tri Valley Bank | Below or Above market-value lease
Other Intangible Assets
Intangible assets acquired					$ 210,000
Useful life, amortization period					11 years
Presidio bank
Other Intangible Assets
Accumulated amortization								524,000
Presidio bank | Core deposit
Other Intangible Assets
Intangible assets acquired			$ 11,247,000
Useful life, amortization period			10 years
Presidio bank | Below or Above market-value lease
Other Intangible Assets
Accumulated amortization			$ (100,000)
Useful life, amortization period			60 months
Focus
Other Intangible Assets
Accumulated amortization								3,504,000	2,770,000
Focus | Core deposit
Other Intangible Assets
Intangible assets acquired						$ 6,285,000
Useful life, amortization period						10 years
BVF/CSNK
Other Intangible Assets
Accumulated amortization								$ 981,000	$ 791,000
BVF/CSNK | Below or Above market-value lease
Other Intangible Assets
Intangible assets acquired							$ 109,000
BVF/CSNK | Non-compete agreement
Other Intangible Assets
Intangible assets acquired							250,000
BVF/CSNK | Customer relationship and brokered relationship
Other Intangible Assets
Intangible assets acquired							$ 1,900,000
Useful life, amortization period							10 years