Loans and Allowance for Loan Losses - Troubled Debt Restructurings (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($) loan	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($) loan	Dec. 31, 2019 USD ($)
Loans Modified as TDRs as of Period End [Abstract]
Accruing	$ 649,000		$ 649,000		$ 700,000
Nonaccrual	38,000		38,000		121,000
Total	$ 687,000		$ 687,000		821,000
Loans Modified as TDRs During the Period [Abstract]
Number of Loans | loan	0	2	2	3
Pre-Modification Outstanding Recorded Investment	$ 0	$ 464,000	$ 37,000	$ 595,000
Post-Modification Outstanding Recorded Investment	0	$ 464,000	37,000	$ 595,000
Number of commitments to lend to customers with outstanding loans that were classified as TDRs	0		0		0
Allowance for loan losses	$ 0		$ 0		4,000
Number of Loans | loan	0	0	1	0
Recorded Investment at Date of Default			$ 26,000	$ 0
Real Estate | Commercial property
Loans Modified as TDRs as of Period End [Abstract]
Accruing	$ 335,000		335,000		339,000
Nonaccrual	0		0		0
Total	$ 335,000		$ 335,000		339,000
Loans Modified as TDRs During the Period [Abstract]
Number of Loans | loan	0	1	0	1
Pre-Modification Outstanding Recorded Investment	$ 0	$ 341,000	$ 0	$ 341,000
Post-Modification Outstanding Recorded Investment	0	$ 341,000	0	$ 341,000
Real Estate | SBA property
Loans Modified as TDRs as of Period End [Abstract]
Accruing	277,000		277,000		294,000
Nonaccrual	38,000		38,000		121,000
Total	$ 315,000		$ 315,000		415,000
Loans Modified as TDRs During the Period [Abstract]
Number of Loans | loan	0	1	0	2
Pre-Modification Outstanding Recorded Investment	$ 0	$ 123,000	$ 0	$ 254,000
Post-Modification Outstanding Recorded Investment	0	$ 123,000	0	$ 254,000
Commercial and Industrial | Commercial term
Loans Modified as TDRs as of Period End [Abstract]
Accruing	22,000		22,000		28,000
Nonaccrual	0		0		0
Total	22,000		22,000		28,000
Commercial and Industrial | SBA commercial term
Loans Modified as TDRs as of Period End [Abstract]
Accruing	15,000		15,000		39,000
Nonaccrual	0		0		0
Total	$ 15,000		$ 15,000		$ 39,000
Loans Modified as TDRs During the Period [Abstract]
Number of Loans | loan			2	0
Pre-Modification Outstanding Recorded Investment			$ 37,000	$ 0
Post-Modification Outstanding Recorded Investment			$ 37,000	$ 0
Number of Loans | loan			1	0
Recorded Investment at Date of Default			$ 26,000	$ 0