Fair value - Recurring and non recurring basis (Details)
$ in Thousands, in Thousands
Mar. 31, 2021
USD ($)
Dec. 31, 2020
UZS ( )
Dec. 31, 2020
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Loans held for sale $ 17,000   $ 34,400
Fair Value, Inputs, Level 2 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Financial Liabilities-Recurring Forward sales commitment |   3,105  
Fair Value, Inputs, Level 3 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Other real estate owned     336
Reported Value Measurement [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Financial Liabilities-Recurring Forward sales commitment     3,105
Other real estate owned     336
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Loans held for sale 17,031   34,421
IRLC 357   1,552
Financial Liabilities-Recurring Forward sales commitment 1,309   3,105
Reported Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Other real estate owned 336   336
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
US Government Agencies 0    
Mortgage-backed securities 0    
Municipals 0    
Subordinated debt 0    
Loans held for sale 0    
IRLC 0    
Financial Liabilities-Recurring Forward sales commitment 0    
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
US Government Agencies 5,906 8,142  
Mortgage-backed securities 26,985 24,006  
Municipals 0    
Subordinated debt 8,030 8,446  
Loans held for sale 17,031 34,421  
IRLC (357) 1,552  
Financial Liabilities-Recurring Forward sales commitment (1,309)    
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
US Government Agencies 0    
Mortgage-backed securities 0    
Municipals 0    
Subordinated debt 250   250
Loans held for sale 0    
IRLC 0    
Financial Liabilities-Recurring Forward sales commitment 0    
Fair Value, Measurements, Recurring [Member] | Reported Value Measurement [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
US Government Agencies 5,906   8,142
Mortgage-backed securities 26,985   24,006
Municipals 1,200    
Subordinated debt 8,280   8,696
Loans held for sale 17,031   34,421
IRLC (357)   $ 1,552
Financial Liabilities-Recurring Forward sales commitment (1,309)    
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Other real estate owned 0    
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Other real estate owned 0    
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Other real estate owned 336    
Fair Value, Measurements, Nonrecurring [Member] | Reported Value Measurement [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Other real estate owned $ 336