Stock Transactions And Stock-Based Compensation (Key Terms of Shares) (Details) - Preferred stock - $ / shares			1 Months Ended
	Apr. 02, 2021	Dec. 31, 2020	May 31, 2020	Mar. 31, 2019
Preferred stock series A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, dividend rate, percent	4.75%	4.75%		4.75%
Preferred stock, liquidation preference per share				$ 1,000
Preferred stock series A | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Convertible preferred stock, shares issued upon conversion				6.6577
Preferred stock series A | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Convertible preferred stock, shares issued upon conversion				8.1556
Preferred stock series B
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, dividend rate, percent	5.00%	5.00%	5.00%
Preferred stock, liquidation preference per share			$ 1,000
Preferred stock series B | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Convertible preferred stock, shares issued upon conversion			5.0088
Preferred stock series B | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Convertible preferred stock, shares issued upon conversion			6.1357