Junior Subordinated Debt/Trust Preferred Securities (Details)	1 Months Ended		3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2015 USD ($)	Aug. 31, 2015 USD ($)	Sep. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) quarter	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2009 USD ($)
Debt Instrument [Line Items]
Gains (losses) on fair value liability, before tax			$ 159,000		$ (277,000)	$ (177,000)	$ (923,000)
Gains (losses) on fair value liability, after tax			97,000		(169,000)	(108,000)		$ (650,000)
Losses on fair value of financial liability, gross					(262,000)		643,000
Losses on fair value financial liability, net					(185,000)		392,000
Gain on fair value of financial liability, gross			660,000			1,571,000
Gain on fair value of financial liability, net			465,000			1,107,000
Unrealized (loss) gain on junior subordinated debentures			(501,000)		(14,000)	(1,748,000)	280,000
Unrealized (loss) gain on junior subordinated debentures net of taxes				$ (1,233,000)	$ (10,000)	(353,000)	$ 197,000
Junior Subordinated Debt
Debt Instrument [Line Items]
Amount of junior subordinated debentures relating to trust preferred securities			12,000,000.0			$ 12,000,000.0			$ 15,000,000
Maximum number of consecutive quarters the entity defer interest payments without default or penalty | quarter						20
Debt instrument, unamortized discount rate		40.00%
Debt instrument, repurchased face amount	$ 3,000,000.0
Gain on redemption of junior subordinated debentures	$ 78,000
Life of the debt instrument		30 years
Fair value measurement option, gain (loss) on long-term debt instruments			$ 2,245,000			$ 2,245,000
Junior Subordinated Debt | Significant Unobservable Inputs (Level 3) | Discount rate | Weighted average
Debt Instrument [Line Items]
Weighted average inputs (percent)			0.0451			0.0451
Junior Subordinated Debt | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate						1.29%
Junior Subordinated Debt | United Security Bank
Debt Instrument [Line Items]
Amount of junior subordinated debentures relating to trust preferred securities		$ 3,000,000.0