Securities - Association's Investments Gross Unrealized Investment Losses and Fair Value of Association's Investments with Unrealized Losses (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Less than 12 Months, Fair Value	$ 28,100	$ 16,097
Less than 12 Months, Unrealized Losses	(256)	(73)
12 Months or More, Fair Value	9,452	31,049
12 Months or More, Unrealized Losses	(149)	(264)
Total Fair Value	37,552	47,146
Total, Unrealized Losses	(405)	(337)
Mortgage-backed Securities - GSE Residential [Member]
Less than 12 Months, Fair Value	24,292	15,167
Less than 12 Months, Unrealized Losses	(205)	(72)
12 Months or More, Fair Value	9,452	31,049
12 Months or More, Unrealized Losses	(149)	(264)
Total Fair Value	33,744	46,216
Total, Unrealized Losses	(354)	(336)
Small Business Administration [Member]
Less than 12 Months, Fair Value	3,747	930
Less than 12 Months, Unrealized Losses	(50)	(1)
Total Fair Value	3,747	930
Total, Unrealized Losses	(50)	$ (1)
State and Political Subdivisions [Member]
Less than 12 Months, Fair Value	61
Less than 12 Months, Unrealized Losses	(1)
Total Fair Value	61
Total, Unrealized Losses	$ (1)