Segment and Geographic Information - Information by Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Net sales	$ 3,993.9	$ 2,991.6	$ 10,692.6	$ 8,254.3
Income (loss) before income taxes	20.2	24.2	55.8	54.7
Interest expense	1.5	0.6	3.3	1.9
Depreciation and amortization	11.4	9.9	31.2	28.3
Capital expenditures	21.7	10.3	44.5	24.7
Reportable Geographical Components | United States Segment
Segment Reporting Information [Line Items]
Net sales	3,591.0	2,657.4	9,634.3	7,312.7
Income (loss) before income taxes	24.8	25.5	59.1	54.2
Interest expense	9.9	9.0	29.7	25.8
Depreciation and amortization	7.7	7.5	22.5	21.7
Capital expenditures	21.1	10.0	42.9	23.9
Reportable Geographical Components | Canada Segment
Segment Reporting Information [Line Items]
Net sales	387.7	323.0	1,030.2	914.9
Income (loss) before income taxes	2.3	1.1	3.4	0.5
Interest expense	0.2	0.2	0.7	0.6
Depreciation and amortization	0.7	0.6	1.9	1.9
Capital expenditures	0.6	0.3	1.6	0.8
Corporate
Segment Reporting Information [Line Items]
Net sales	15.2	11.2	28.1	26.7
Income (loss) before income taxes	(6.9)	(2.4)	(6.7)	0.0
Depreciation and amortization	3.0	1.8	6.8	4.7
Intersegment Eliminations
Segment Reporting Information [Line Items]
Interest expense	$ (8.6)	$ (8.6)	$ (27.1)	$ (24.5)