Note 9. Employee Benefit Plans (Details) - USD ($)	9 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Jun. 30, 2022
Components of Net Periodic Benefit Cost (before tax):
Assets for Plan Benefits, Defined Benefit Plan	$ 0		$ 0
SERP investments	8,400,000		10,400,000
SERP obligation	8,400,000		10,400,000
Equity Securities, FV-NI, Unrealized Gain (Loss)	100,000	$ (1,100,000)
Other Current Liabilities
Components of Net Periodic Benefit Cost (before tax):
SERP obligation	2,700,000		2,600,000
Other Noncurrent Liabilities
Components of Net Periodic Benefit Cost (before tax):
SERP obligation	5,700,000		7,800,000
Prepaid Expenses and Other Current Assets
Components of Net Periodic Benefit Cost (before tax):
SERP investments	2,700,000		2,600,000
Other Noncurrent Assets
Components of Net Periodic Benefit Cost (before tax):
SERP investments	$ 5,700,000		$ 7,800,000