Stockholders' Equity Preferred Stock (Details) - EID [Member] - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
$4.50 Series Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	23,000,000	23,000,000	23,000,000
Preferred Stock, Shares Issued	1,673,000	1,673,000	1,673,000
Preferred Stock, Redemption Amount	$ 120	$ 120	$ 120
$3.50 Series Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	23,000,000	23,000,000	23,000,000
Preferred Stock, Shares Issued	700,000	700,000	700,000
Preferred Stock, Redemption Amount	$ 102	$ 102	$ 102
Corteva [Member]
Class of Stock [Line Items]
Ownership interest in an entity	100.00%