Investment Securities - Schedule of Held to maturity Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020
Held to maturity, Amortized Cost
Due in one year or less	$ 600	$ 800
Due after one through five years	21,057	19,389
Due after five through ten years	69,215	50,895
Due after ten years	102,996	47,543
Total investment securities - held to maturity, Amortized Cost	193,868	118,627
Held to maturity, Estimated Fair Value
Due in one year or less	600	800
Due after one through five years	21,956	20,194
Due after five through ten years	70,425	52,315
Due after ten years	103,566	47,892
Total investment securities - held to maturity, Estimated Fair Value	$ 196,547	$ 121,201