Loans and Allowance for Credit Losses - Troubled debt restructurings (TDRs) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Loans and Allowance for Credit Losses
TDR Loans, Number	36
TDR Loans, Balance	$ 2,949
One- to four-family residential
Loans and Allowance for Credit Losses
TDR Loans, Number	16
TDR Loans, Balance	$ 1,126
Commercial real estate
Loans and Allowance for Credit Losses
TDR Loans, Number	2
TDR Loans, Balance	$ 1,571
Consumer
Loans and Allowance for Credit Losses
TDR Loans, Number	18
TDR Loans, Balance	$ 252
Accruing TDR Loans
Loans and Allowance for Credit Losses
TDR Loans, Number	26
TDR Loans, Balance	$ 1,238
Accruing TDR Loans | One- to four-family residential
Loans and Allowance for Credit Losses
TDR Loans, Number	13
TDR Loans, Balance	$ 1,028
Accruing TDR Loans | Consumer
Loans and Allowance for Credit Losses
TDR Loans, Number	13
TDR Loans, Balance	$ 210
Non-accruing TDR Loans
Loans and Allowance for Credit Losses
TDR Loans, Number	10
TDR Loans, Balance	$ 1,711
Non-accruing TDR Loans | One- to four-family residential
Loans and Allowance for Credit Losses
TDR Loans, Number	3
TDR Loans, Balance	$ 98
Non-accruing TDR Loans | Commercial real estate
Loans and Allowance for Credit Losses
TDR Loans, Number	2
TDR Loans, Balance	$ 1,571
Non-accruing TDR Loans | Consumer
Loans and Allowance for Credit Losses
TDR Loans, Number	5
TDR Loans, Balance	$ 42