Summary Of Significant Accounting Policies (Estimated Useful Lives Of The Related Assets) (Details)	12 Months Ended
	Dec. 31, 2019
Buildings And Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, useful life	5 years
Buildings And Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, useful life	40 years
Machinery And Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, useful life	2 years
Machinery And Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, useful life	25 years
Automobiles, Trucks, Tractors And Trailers [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, useful life	3 years
Automobiles, Trucks, Tractors And Trailers [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, useful life	10 years
Furniture And Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, useful life	2 years
Furniture And Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, useful life	10 years