Securities, Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017
Available-for-sale Debt Securities, Amortized Cost [Abstract]
Within one year	$ 92,308
After one year through five years	4,544
After five years through ten years	2,514
After ten years	0
Total available-for-sale debt securities	99,366
Mortgage-backed and asset-backed securities	21,581
Equity securities	62	$ 62
Amortized cost	121,009	90,491
Available-for-sale Debt Securities, Fair Value [Abstract]
Within one year	92,509
After one year through five years	4,562
After five years through ten years	2,419
After ten years	0
Total available-for-sale debt securities	99,490
Mortgage-backed and asset-backed securities	21,316
Equity securities	217	184
Estimated fair value	121,023	91,483
Held-to-maturity Debt Securities, Amortized Cost [Abstract]
Within one year	25,649
After one year through five years	61,602
After five years through ten years	44,811
After ten years	17,236
Total held-to-maturity debt securities	149,298
Mortgage-backed	125,252
Amortized cost	274,550	223,830
Held-to-maturity Debt Securities, Fair Value [Abstract]
Within one year	25,808
After one year through five years	62,320
After five years through ten years	45,185
After ten years	18,269
Total held-to-maturity debt securities	151,582
Mortgage-backed securities	122,595
Estimated fair value	274,177	228,452
Total Securities [Abstract]
Amortized cost	395,559	314,321
Estimated fair value	395,200	319,935
Securities pledged as collateral for deposits in excess of FDIC insurance limits, fair value	383,000	305,700
Securities pledged as collateral for potential borrowings at the Federal Reserve Bank discount window	$ 1,700	$ 2,800