Loans Held For Investment Loans Held For Investment: Schedule of Past Due Status of Loans Held for Investment, Gross (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans deemed uncollectible, period of delinquency	90 days	90 days
Loans Held For Investment, Gross, Current	$ 918,645	$ 874,032
30-89 Days Past Due	990	665
Non-Accrual	5,370	6,641
Total Loans Held for Investment, Gross	925,005	881,338	$ 878,860
Mortgage loans, Single-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Held For Investment, Gross, Current	323,159	318,671
30-89 Days Past Due	987	660
Non-Accrual	4,186	5,621
Total Loans Held for Investment, Gross	328,332	324,952	307,480
Mortgage loans, Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Held For Investment, Gross, Current	110,652	111,928
30-89 Days Past Due	0	0
Non-Accrual	0	0
Total Loans Held for Investment, Gross	110,652	111,928	112,026
Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Held For Investment, Gross, Current	4,773	3,667
30-89 Days Past Due	0	0
Non-Accrual	1,139	971
Total Loans Held for Investment, Gross	5,912	4,638	3,846
Commercial business loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Held For Investment, Gross, Current	323	429
30-89 Days Past Due	0	0
Non-Accrual	45	49
Total Loans Held for Investment, Gross	368	478	416
Consumer loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Held For Investment, Gross, Current	141	129
30-89 Days Past Due	3	5
Non-Accrual	0	0
Total Loans Held for Investment, Gross	144	134	104
Mortgage Loans Multi Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Held For Investment, Gross, Current	479,597	439,041
30-89 Days Past Due	0	0
Non-Accrual	0	0
Total Loans Held for Investment, Gross	$ 479,597	439,041	454,821
Bankruptcy [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans deemed uncollectible, period of delinquency	60 days
Mortgage Loans Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Held For Investment, Gross, Current		167
30-89 Days Past Due		0
Non-Accrual		0
Total Loans Held for Investment, Gross		$ 167	$ 167
Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans deemed uncollectible, period of delinquency	90 days
Commercial Real Estate Or Second Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans deemed uncollectible, period of delinquency	120 days