Segment and Geographic Information - Information by Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Net sales	$ 3,687.4	$ 2,810.4	$ 6,698.7	$ 5,262.7
Income (loss) before income taxes	26.4	21.4	35.6	30.5
Interest expense	1.0	0.7	1.8	1.3
Depreciation and amortization	10.2	9.7	19.8	18.4
Capital expenditures	14.0	11.7	22.8	14.4
Reportable Geographical Components | United States Segment
Segment Reporting Information [Line Items]
Net sales	3,307.1	2,479.2	6,043.3	4,655.3
Income (loss) before income taxes	29.4	22.2	34.3	28.7
Interest expense	10.2	8.6	19.8	16.8
Depreciation and amortization	7.4	7.5	14.8	14.2
Capital expenditures	13.3	11.3	21.8	13.9
Reportable Geographical Components | Canada Segment
Segment Reporting Information [Line Items]
Net sales	373.1	324.1	642.5	591.9
Income (loss) before income taxes	1.3	(0.4)	1.1	(0.6)
Interest expense	0.2	0.2	0.5	0.4
Depreciation and amortization	0.7	0.7	1.2	1.3
Capital expenditures	0.7	0.4	1.0	0.5
Intersegment Eliminations
Segment Reporting Information [Line Items]
Interest expense	(9.4)	(8.1)	(18.5)	(15.9)
Corporate
Segment Reporting Information [Line Items]
Net sales	7.2	7.1	12.9	15.5
Income (loss) before income taxes	(4.3)	(0.4)	0.2	2.4
Depreciation and amortization	$ 2.1	$ 1.5	$ 3.8	$ 2.9