Debt Securities - Schedule of Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020
Amortized Cost
Due within one year	$ 28,086
Due after one year through five years	18,910
Due after five years through ten years	3,176
Due after ten years	732
Total	93,342
Estimated Fair Value
Due within one year	28,188
Due after one year through five years	19,640
Due after five years through ten years	3,418
Due after ten years	732
Estimated Fair Value	96,159	$ 127,537
Residential MBS of U.S. Government Agencies and GSEs
Amortized Cost
Total	42,438
Estimated Fair Value
Estimated Fair Value	$ 44,181	$ 48,355