Note 9. Investments - Supplemental Employee Retirement Investments Textuals (Details) - USD ($) $ in Thousands	3 Months Ended
Sep. 30, 2020	Sep. 30, 2019
Schedule of Trading Securities and Other Trading Assets
Trading Securities, Change in net unrealized holding gains (losses)	$ 200	$ (100)

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