Condensed Consolidated Statement of Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2019
Common stock, par value (in usd per share)	$ 1				$ 1
Common Stock
Common stock, par value (in usd per share)	1	$ 1	$ 1	$ 1
Common stock, dividends, per share, cash paid (in usd per share)	0.545	0.575	0.575	0.545
Class B Common Stock
Common stock, par value (in usd per share)	1	1	1	1	$ 1
Common stock, dividends, per share, cash paid (in usd per share)	0.545	0.575	0.575	0.545
Series A Preferred Stock
Preferred stock, dividends, per share, cash paid (in usd per share)	$ 22.19	$ 22.19	$ 21.72	$ 21.49