Nonaccrual Loans (Details) - Nonperforming - USD ($) $ in Thousands	Dec. 31, 2021	Mar. 31, 2021
Financing Receivable, Past Due [Line Items]
Financing Receivable, Nonaccrual	$ 7,768	$ 7,191
One-to-four family
Financing Receivable, Past Due [Line Items]
Financing Receivable, Nonaccrual	4,919	3,524
Multifamily
Financing Receivable, Past Due [Line Items]
Financing Receivable, Nonaccrual	516	369
Commercial real estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, Nonaccrual	185	918
Business
Financing Receivable, Past Due [Line Items]
Financing Receivable, Nonaccrual	2,091	2,290
Consumer
Financing Receivable, Past Due [Line Items]
Financing Receivable, Nonaccrual	$ 57	$ 90