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.

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Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Revenue (Details) - USD ($) $ in Millions	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Performance obligation	$ 0.0		$ 0.0		$ 0.0
Accrued sales returns	2.1		2.1		$ 1.8
Revenue from contracts with customers	248.6	$ 231.2	480.8	$ 443.4
Service Revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0.0	0.0	0.0	0.0
MRO Products and Industrial Supplies \| Reportable Geographical Components \| United States
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	236.7	220.4	457.5	422.4
MRO Products and Industrial Supplies \| Reportable Geographical Components \| Canada
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 11.9	$ 10.8	$ 23.3	$ 21.0
Revenue from Contract with Customer \| Product Concentration Risk \| Service Revenue
Disaggregation of Revenue [Line Items]
Service revenue, percentage of revenue	1.00%	1.00%	1.00%	1.00%