Shareholders' Equity - Additional Information (Detail) - USD ($)	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Oct. 08, 2019	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted	0	50,000
Share options exercised, Shares	70,000	0
Options outstanding	410,000	480,000		595,000
Options forfeited		165,000
Share-based compensation, amount recognized	$ 0	$ 28,000
Unrecognized compensation cost	0
Aggregate intrinsic value of options exercisable	594,000	132,000
Aggregate intrinsic value of options outstanding	$ 594,000	132,000
Stock repurchased during period, value		$ 102,000
Stock repurchased during period, shares	87,534
Stock repurchased during period, average price of per share	$ 1.15
2019-2020 Common Share Repurchase Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchased during period, value	$ 101,000
Stock repurchased during period, shares	87,534
Stock repurchased during period, average price of per share	$ 1.15
2005 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Plan, Description	The 2005 Equity Incentive Plan approved by SunLink’s shareholders on November 7, 2005 permitted the grant of options to employees, non-employee directors and service providers of SunLink for the purchase of up to 800,000 common shares plus the number of unused shares under its 2001 Plans, which were 30,675.
Options granted	0	0
Share options exercised, Shares	0
Options outstanding	180,000
Options forfeited	165,000
Shares available for grants	0
Maximum [Member] | 2019-2020 Common Share Repurchase Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of shares authorized to be repurchased			$ 750,000
Maximum [Member] | 2005 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase of common shares	800,000
2011 Director Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Plan, Description	The 2011 Director Stock Option Plan was approved by SunLink’s shareholders at the Annual Meeting of Shareholders on November 7, 2011. This plan permits the grant of options to non-employee directors of SunLink for the purchase of up to 300,000 common shares through November 2021.
Options granted	0	50,000
Share options exercised, Shares	70,000
Options outstanding	230,000
2011 Director Stock Option Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase of common shares	300,000
2001 Plans [Member] | 2005 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares restricted under share based plan	30,675