Revenue - Percentages of Sales by End Market (Details) - End Market - Sales	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Percentage of Sales by End Market [Line Items]
Percentage of sales	100.00%	100.00%	100.00%
Manufacturing
Percentage of Sales by End Market [Line Items]
Percentage of sales	66.70%	66.50%	65.90%
Non-residential construction
Percentage of Sales by End Market [Line Items]
Percentage of sales	13.10%	13.00%	13.60%
Other
Percentage of Sales by End Market [Line Items]
Percentage of sales	20.20%	20.50%	20.50%

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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: 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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-Name Accounting Standards Codification
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