Revenue (Disaggregation Of Revenue) (Details) - Revenue from Contract with Customer [Member]	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Total net sales	100.00%	100.00%	100.00%
Construction
Disaggregation of Revenue [Line Items]
Total net sales	58.10%	58.40%	58.20%
CIG
Disaggregation of Revenue [Line Items]
Total net sales	26.80%	26.50%	26.20%
Industrial & Utility
Disaggregation of Revenue [Line Items]
Total net sales	15.10%	15.10%	15.60%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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