CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Common shares [Member]	Accumulated other comprehensive income (loss) [Member]	Retained earnings [Member]	Total
Balance at beginning at Jun. 30, 2019	$ 15,815	$ (549)	$ 1,742	$ 17,008
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	$ 19
Share repurchases (in shares)	(2,215)
Shares withheld from common stock issued to pay employee payroll taxes, shares
Exercise of stock options
ESPP shares issued (in shares)	15
Cumulative effect of change in accounting principle			42
Net income			$ 2,354	$ 2,354
Net change in unrealized gain from marketable securities, net of taxes		$ 649
Balance at end (in shares) at Dec. 31, 2019	13,634	100	4,138	17,872
Balance at beginning at Sep. 30, 2019	$ 15,161	$ (605)	$ 2,889	$ 17,444
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	$ 8
Share repurchases (in shares)	(1,535)
Shares withheld from common stock issued to pay employee payroll taxes, shares
Exercise of stock options
ESPP shares issued (in shares)
Cumulative effect of change in accounting principle
Net income			$ 1,249	$ 1,249
Net change in unrealized gain from marketable securities, net of taxes		$ 705
Balance at end (in shares) at Dec. 31, 2019	13,634	100	4,138	17,872
Balance at beginning at Jun. 30, 2020	$ 12,752	$ (1,586)	$ 7,896	$ 19,062
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	64
Share repurchases
Shares withheld from common stock issued to pay employee payroll taxes, shares	(259)
Exercise of stock options	$ 39
ESPP shares issued (in shares)	25
Cumulative effect of change in accounting principle
Net income			1,602	1,602
Net change in unrealized gain from marketable securities, net of taxes		1,306
Balance at end at Dec. 31, 2020	$ 12,621	(280)	9,498	21,839
Balance at beginning at Sep. 30, 2020	12,583	(1,693)	9,161	20,051
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	38
Share repurchases
Shares withheld from common stock issued to pay employee payroll taxes, shares
Exercise of stock options
ESPP shares issued (in shares)
Cumulative effect of change in accounting principle
Net income			337	337
Net change in unrealized gain from marketable securities, net of taxes		1,413		1,413
Balance at end at Dec. 31, 2020	$ 12,621	$ (280)	$ 9,498	$ 21,839