Revenue (Disaggregation Of Revenue) (Details) - Revenue from Contract with Customer [Member]	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Total net sales	100.00%	100.00%	100.00%
Construction
Disaggregation of Revenue [Line Items]
Total net sales	60.10%	59.70%	58.70%
Industrial & Utility
Disaggregation of Revenue [Line Items]
Total net sales	20.60%	20.80%	21.10%
CIG
Disaggregation of Revenue [Line Items]
Total net sales	19.30%	19.50%	20.20%