Note 10. Stock Compensation Plans Deferred Share Units (Details) - Non-Employee Directors Stock Compensation Deferral Plan - Deferred Share Units Director Compensation - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangements
Share-based Compensation Arrangements, Grants in Period	32,950	32,758	12,159
Share-based Compensation Arrangements, Grants in Period, Weighted Average Grant Date Fair Value	$ 17.30	$ 17.40	$ 20.15
Share-based Compensation Arrangements, Vested in Period, Fair Value	$ 0.6	$ 0.6	$ 0.2
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	2,754
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 17.51