Condensed Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Jun. 30, 2019
Common Stock
Common stock, par value (in usd per share)	$ 1	$ 1	$ 1	$ 1	$ 1	$ 1	$ 1	$ 1
Common stock, dividends, per share, cash paid (in usd per share)	0.595	0.575	0.575
Class B Common Stock
Common stock, par value (in usd per share)	1	1	1	$ 1	$ 1	$ 1	$ 1	$ 1
Common stock, dividends, per share, cash paid (in usd per share)	0.595	0.575	0.575
Series A Preferred Stock
Preferred stock, dividends, per share, cash paid (in usd per share)	$ 21.49	$ 21.72	$ 22.19