Securities - Association's Investments Gross Unrealized Investment Losses and Fair Value of Association's Investments with Unrealized Losses (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Jun. 30, 2023
Less than 12 Months, Fair Value	$ 7,506	$ 16,728
Less than 12 Months, Unrealized Losses	(198)	(506)
12 Months or More, Fair Value	185,506	178,090
12 Months or More, Unrealized Losses	(27,921)	(29,889)
Total, Fair Value	193,012	194,818
Total, Unrealized Losses	(28,119)	(30,395)
U.S. Treasury [Member]
Less than 12 Months, Fair Value	0	0
Less than 12 Months, Unrealized Losses	0	0
12 Months or More, Fair Value	447	438
12 Months or More, Unrealized Losses	(49)	(59)
Total, Fair Value	447	438
Total, Unrealized Losses	(49)	(59)
U.S. Government and federal agency [Member]
Less than 12 Months, Fair Value	0	0
Less than 12 Months, Unrealized Losses	0	0
12 Months or More, Fair Value	6,584	6,477
12 Months or More, Unrealized Losses	(394)	(499)
Total, Fair Value	6,584	6,477
Total, Unrealized Losses	(394)	(499)
Mortgage-backed: GSE residential [Member]
Less than 12 Months, Fair Value	6,268	14,517
Less than 12 Months, Unrealized Losses	(179)	(440)
12 Months or More, Fair Value	162,826	158,413
12 Months or More, Unrealized Losses	(25,153)	(26,994)
Total, Fair Value	169,092	172,930
Total, Unrealized Losses	(25,332)	(27,434)
Small Business Administration [Member]
Less than 12 Months, Fair Value	1,238	1,148
Less than 12 Months, Unrealized Losses	(19)	(60)
12 Months or More, Fair Value	13,414	12,762
12 Months or More, Unrealized Losses	(2,246)	(2,337)
Total, Fair Value	14,654	13,910
Total, Unrealized Losses	(2,265)	(2,397)
State and political subdivisions [Member]
Less than 12 Months, Fair Value	0	1,063
Less than 12 Months, Unrealized Losses	0	(6)
12 Months or More, Fair Value	2,235	0
12 Months or More, Unrealized Losses	(79)	0
Total, Fair Value	2,235	1,063
Total, Unrealized Losses	$ (79)	$ (6)