Note 15. Investments - Investments-Supplemental Employee Retirement Plan Investments Textuals (Details) - USD ($) $ in Thousands	12 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Schedule of Trading Securities and Other Trading Assets
Trading Securities, Change in net unrealized holding gains (losses)	$ 385	$ 35	$ 552

Amount of unrealized holding gain (loss) recognized in the income statement for investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

No definition available.

Name:	us-gaap_TradingSecuritiesUnrealizedHoldingGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration