Revenue - Percentages of Sales by End Market (Details) - End Market - Sales	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Percentage of Sales by End Market [Line Items]
Percentage of sales	100.00%	100.00%	100.00%	100.00%
Manufacturing
Percentage of Sales by End Market [Line Items]
Percentage of sales	67.30%	66.60%	67.50%	66.80%
Non-residential construction
Percentage of Sales by End Market [Line Items]
Percentage of sales	13.20%	13.20%	12.90%	12.90%
Other
Percentage of Sales by End Market [Line Items]
Percentage of sales	19.50%	20.20%	19.60%	20.30%

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
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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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