Securities, Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Jun. 30, 2019
Available-for-sale Debt Securities, Amortized Cost [Abstract]
Within one year	$ 169,715
After one year through five years	1,581
After five years through ten years	1,544
After ten years	2,000
Total available for sale debt securities	174,840
Mortgage-backed securities	33,107
Amortized cost	207,947
Available-for-sale Debt Securities, Fair Value [Abstract]
Within one year	169,918
After one through five years	1,629
After five through ten years	1,562
After ten years	1,888
Total available-for-sale debt securities	174,997
Mortgage-backed securities	34,125
Estimated fair value	209,122	$ 122,728
Held-to-maturity Debt Securities, Amortized Cost [Abstract]
Within one year	33,677
After one year through five years	92,123
After five years through ten years	51,143
After ten years	23,326
Total held-to-maturity debt securities	200,269
Mortgage-backed securities	182,263
Amortized cost	382,532	304,208
Held-to-maturity Debt Securities, Fair Value [Abstract]
Within one year	34,000
After one year through five years	94,198
After five years through ten years	53,945
After ten years	26,321
Total held-to-maturity debt securities	208,464
Mortgage-backed securities	190,792
Estimated fair value	399,256	313,613
Total Debt Securities [Abstract]
Amortized cost	590,479	425,810
Estimated fair value	608,378	436,341
Securities pledged as collateral for deposits in excess of FDIC insurance limits, fair value	595,900	425,700
Securities pledged as collateral for potential borrowings at the Federal Reserve Bank discount window	$ 4,500	$ 1,500