Nature of Business and Summary of Significant Accounting Policies - Intangible Assets (Details) - USD ($)	1 Months Ended	12 Months Ended
	Aug. 31, 2008	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Intangible assets
Impairment of intangible asset			$ 1,852,000
Useful life	20 years		20 years
Amortization expense		$ 425,000	$ 264,000	$ 313,000
Changes in intangible assets
Carrying value		13,848,000	13,848,000	15,700,000
Accumulated amortization		(9,157,000)	(8,732,000)	(8,468,000)
Net book value		4,691,000	$ 5,116,000	7,232,000
Future amortization expense
2023		390,000
2024		361,000
2025		336,000
2026		315,000
2026		$ 297,000
Weighted average remaining period		16 years 10 months 24 days	17 years 6 months
Customer relationships [Member]
Changes in intangible assets
Carrying value		$ 9,800,000	$ 9,800,000	9,800,000
Accumulated amortization		(8,955,000)	(8,732,000)	(8,468,000)
Net book value		845,000	1,068,000	1,332,000
Trade name
Changes in intangible assets
Carrying value		4,048,000	4,048,000	5,900,000
Accumulated amortization		(202,000)
Net book value		$ 3,846,000	$ 4,048,000	$ 5,900,000