Revenue (Disaggregation Of Revenue) (Details) - Revenue from Contract with Customer [Member]	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total net sales	100.00%	100.00%	100.00%	100.00%
Construction
Disaggregation of Revenue [Line Items]
Total net sales	58.50%	59.10%	58.10%	58.60%
CIG
Disaggregation of Revenue [Line Items]
Total net sales	26.90%	26.40%	26.90%	26.40%
Industrial & Utility
Disaggregation of Revenue [Line Items]
Total net sales	14.60%	14.50%	15.00%	15.00%

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://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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