Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Non-recurring Basis (Details) - Nonrecurring - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Impaired loans:
Total impaired loans		$ 1,377
Total assets measured at fair value on a recurring basis	$ 0	1,377
Total liabilities measured at fair value on a recurring basis	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1)
Impaired loans:
Total impaired loans		0
Total assets measured at fair value on a recurring basis	0	0
Total liabilities measured at fair value on a recurring basis	0	0
Significant Other Observable Inputs (Level 2)
Impaired loans:
Total impaired loans		0
Total assets measured at fair value on a recurring basis	0	0
Total liabilities measured at fair value on a recurring basis	0	0
Significant Unobservable Inputs (Level 3)
Impaired loans:
Total impaired loans		1,377
Total assets measured at fair value on a recurring basis	0	1,377
Total liabilities measured at fair value on a recurring basis	$ 0	0
SBA property
Impaired loans:
Total impaired loans		218
SBA property | Quoted Prices in Active Markets for Identical Assets (Level 1)
Impaired loans:
Total impaired loans		0
SBA property | Significant Other Observable Inputs (Level 2)
Impaired loans:
Total impaired loans		0
SBA property | Significant Unobservable Inputs (Level 3)
Impaired loans:
Total impaired loans		218
Commercial lines of credit
Impaired loans:
Total impaired loans		904
Commercial lines of credit | Quoted Prices in Active Markets for Identical Assets (Level 1)
Impaired loans:
Total impaired loans		0
Commercial lines of credit | Significant Other Observable Inputs (Level 2)
Impaired loans:
Total impaired loans		0
Commercial lines of credit | Significant Unobservable Inputs (Level 3)
Impaired loans:
Total impaired loans		904
SBA commercial term
Impaired loans:
Total impaired loans		255
SBA commercial term | Quoted Prices in Active Markets for Identical Assets (Level 1)
Impaired loans:
Total impaired loans		0
SBA commercial term | Significant Other Observable Inputs (Level 2)
Impaired loans:
Total impaired loans		0
SBA commercial term | Significant Unobservable Inputs (Level 3)
Impaired loans:
Total impaired loans		$ 255