Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Thousands	1 Months Ended					3 Months Ended
	Oct. 31, 2019	May 31, 2018	Apr. 30, 2018	Aug. 31, 2015	Nov. 30, 2014	Mar. 31, 2020	Dec. 31, 2019	Oct. 11, 2019	May 04, 2018	Apr. 06, 2018	Aug. 20, 2015	Nov. 01, 2014
United American Bank
Other Intangible Assets
Accumulated amortization						$ 2,019	$ 1,778
United American Bank | Core deposit
Other Intangible Assets
Intangible assets acquired									$ 5,723
Useful life, amortization period		10 years
United American Bank | Below market-value lease
Other Intangible Assets
Intangible assets acquired									$ 660
Useful life, amortization period		3 years				3 years
Tri Valley Bank
Other Intangible Assets
Accumulated amortization						$ 537	480
Tri Valley Bank | Core deposit
Other Intangible Assets
Intangible assets acquired										$ 1,768
Useful life, amortization period			10 years
Tri Valley Bank | Below market-value lease
Other Intangible Assets
Intangible assets acquired										$ 210
Useful life, amortization period			11 years			11 years
Presidio bank
Other Intangible Assets
Accumulated amortization						$ 870	524
Useful life, amortization period	60 months
Presidio bank | Core deposit
Other Intangible Assets
Intangible assets acquired								$ 11,247
Useful life, amortization period	10 years
Presidio bank | Below or Above market-value lease
Other Intangible Assets
Accumulated amortization								$ (100)
Useful life, amortization period	60 months					5 years
Focus
Other Intangible Assets
Accumulated amortization						$ 3,683	3,504
Focus | Core deposit
Other Intangible Assets
Intangible assets acquired											$ 6,285
Useful life, amortization period				10 years
BVF/CSNK
Other Intangible Assets
Accumulated amortization						$ 1,028	$ 981
BVF/CSNK | Below market-value lease
Other Intangible Assets
Intangible assets acquired												$ 109
BVF/CSNK | Non-compete agreement
Other Intangible Assets
Intangible assets acquired												250
BVF/CSNK | Customer relationship and brokered relationship
Other Intangible Assets
Intangible assets acquired												$ 1,900
Useful life, amortization period					10 years