Loans and Allowance for Credit Losses - Geographic and Collateral Concentration (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Geographical concentration | Loans, net
Concentration risk
Percentage of loan	100.00%	100.00%
Geographical concentration | Loans, net | Texas
Concentration risk
Percentage of loan	19.20%	14.20%
Geographical concentration | Loans, net | California
Concentration risk
Percentage of loan	14.30%	18.10%
Geographical concentration | Loans, net | Arizona
Concentration risk
Percentage of loan	7.40%	2.80%
Geographical concentration | Loans, net | New York
Concentration risk
Percentage of loan	7.30%	9.80%
Geographical concentration | Loans, net | Georgia
Concentration risk
Percentage of loan	7.00%	4.90%
Geographical concentration | Loans, net | Florida
Concentration risk
Percentage of loan	6.70%	7.80%
Geographical concentration | Loans, net | Illinois
Concentration risk
Percentage of loan	4.30%	5.20%
Geographical concentration | Loans, net | North Carolina
Concentration risk
Percentage of loan	2.60%	3.10%
Geographical concentration | Loans, net | Washington
Concentration risk
Percentage of loan	2.10%	3.10%
Geographical concentration | Loans, net | Colorado
Concentration risk
Percentage of loan	1.90%	2.80%
Geographical concentration | Loans, net | Other
Concentration risk
Percentage of loan	27.20%	28.20%
Collateral concentration
Concentration risk
Percentage of SBA loan	100.00%	100.00%
Collateral concentration | Lodging
Concentration risk
Percentage of SBA loan	17.00%	17.20%
Collateral concentration | Offices of Physicians
Concentration risk
Percentage of SBA loan	10.90%	12.00%
Collateral concentration | Child Day Care Services
Concentration risk
Percentage of SBA loan	7.40%	7.20%
Collateral concentration | Eating Places
Concentration risk
Percentage of SBA loan	5.00%	5.30%
Collateral concentration | Gasoline Service Stations
Concentration risk
Percentage of SBA loan	3.70%	3.40%
Collateral concentration | Veterinarians
Concentration risk
Percentage of SBA loan	2.40%	3.30%
Collateral concentration | Funeral Service and Crematories
Concentration risk
Percentage of SBA loan	1.90%	1.80%
Collateral concentration | Grocery Stores
Concentration risk
Percentage of SBA loan	1.80%	1.70%
Collateral concentration | Car Washes
Concentration risk
Percentage of SBA loan	1.40%	1.40%
Collateral concentration | Couriers
Concentration risk
Percentage of SBA loan	1.30%	1.00%
Collateral concentration | Other
Concentration risk
Percentage of SBA loan	47.20%	45.70%
Collateral concentration | Loans, net
Concentration risk
Percentage of loan	100.00%	100.00%
Collateral concentration | Loans, net | Multi-family
Concentration risk
Percentage of loan	54.40%	23.80%
Collateral concentration | Loans, net | SBA
Concentration risk
Percentage of loan	8.70%	17.40%
Collateral concentration | Loans, net | Retail
Concentration risk
Percentage of loan	10.20%	17.30%
Collateral concentration | Loans, net | Office
Concentration risk
Percentage of loan	8.20%	13.10%
Collateral concentration | Loans, net | Mixed Use
Concentration risk
Percentage of loan	7.10%	12.90%
Collateral concentration | Loans, net | Industrial
Concentration risk
Percentage of loan	6.40%	7.10%
Collateral concentration | Loans, net | Lodging/Residential
Concentration risk
Percentage of loan	1.80%	3.20%
Collateral concentration | Loans, net | Other
Concentration risk
Percentage of loan	3.20%	5.20%