Investment Securities - Schedule of Amortized Cost, Gross Unrealized/Unrecognized Gains and Losses and Fair Value of Available for Sale and Held to Maturity Debt Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Jun. 30, 2019
Schedule of Investments [Line Items]
Available for sale, Amortized Cost	$ 45,869	$ 72,491
Available for sale, Gross Unrealized/Unrecognized Gains	303	48
Available for sale, Gross Unrealized/Unrecognized Losses	(180)	(311)
Available for sale, Fair Value	45,992	72,228
Held to maturity, Amortized Cost	263,626	345,545
Held to maturity, Gross Unrealized/Unrecognized Gains	6,844	1,905
Held to maturity, Gross Unrealized/Unrecognized Losses	(2,766)	(1,207)
Held to maturity, Fair Value	267,704	346,243
U.S. Government and Agency Obligations [Member]
Schedule of Investments [Line Items]
Available for sale, Amortized Cost	19,006	37,027
Available for sale, Gross Unrealized/Unrecognized Gains	83	5
Available for sale, Gross Unrealized/Unrecognized Losses		(121)
Available for sale, Fair Value	19,089	36,911
Held to maturity, Amortized Cost	33,002	96,545
Held to maturity, Gross Unrealized/Unrecognized Gains	500	192
Held to maturity, Gross Unrealized/Unrecognized Losses		(246)
Held to maturity, Fair Value	33,502	96,491
Corporate and Other Debt Securities [Member]
Schedule of Investments [Line Items]
Available for sale, Amortized Cost	5,044	8,349
Available for sale, Gross Unrealized/Unrecognized Gains	71	20
Available for sale, Gross Unrealized/Unrecognized Losses	(89)	(9)
Available for sale, Fair Value	5,026	8,360
Held to maturity, Amortized Cost	46,107	34,033
Held to maturity, Gross Unrealized/Unrecognized Gains	90	133
Held to maturity, Gross Unrealized/Unrecognized Losses	(2,762)	(413)
Held to maturity, Fair Value	43,435	33,753
Mortgage-backed Securities - Residential [Member]
Schedule of Investments [Line Items]
Available for sale, Amortized Cost	21,819	27,115
Available for sale, Gross Unrealized/Unrecognized Gains	149	23
Available for sale, Gross Unrealized/Unrecognized Losses	(91)	(181)
Available for sale, Fair Value	21,877	26,957
Held to maturity, Amortized Cost	116,666	133,602
Held to maturity, Gross Unrealized/Unrecognized Gains	3,839	818
Held to maturity, Gross Unrealized/Unrecognized Losses	(2)	(372)
Held to maturity, Fair Value	120,503	134,048
Mortgage-backed Securities - Collateralized Mortgage Obligations [Member]
Schedule of Investments [Line Items]
Held to maturity, Amortized Cost	47,581	52,940
Held to maturity, Gross Unrealized/Unrecognized Gains	1,589	311
Held to maturity, Gross Unrealized/Unrecognized Losses		(147)
Held to maturity, Fair Value	49,170	53,104
Mortgage-backed Securities - Commercial [Member]
Schedule of Investments [Line Items]
Held to maturity, Amortized Cost	20,270	28,425
Held to maturity, Gross Unrealized/Unrecognized Gains	826	451
Held to maturity, Gross Unrealized/Unrecognized Losses	(2)	(29)
Held to maturity, Fair Value	$ 21,094	$ 28,847