Segment and Geographic Information - Information by Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Net sales	$ 4,310.7	$ 3,993.9	$ 11,615.6	$ 10,692.6
Income (loss) before income taxes	21.8	20.2	33.9	55.8
Interest expense	3.9	1.5	7.9	3.3
Depreciation and amortization	15.3	11.4	39.6	31.2
Capital expenditures	13.2	21.7	44.0	44.5
Operating Segment | United States Segment
Segment Reporting Information [Line Items]
Net sales	3,904.6	3,591.0	10,539.9	9,634.3
Income (loss) before income taxes	27.2	24.8	42.8	59.1
Interest expense	13.1	9.9	34.6	29.7
Depreciation and amortization	10.3	7.7	27.7	22.5
Capital expenditures	12.7	21.1	42.6	42.9
Operating Segment | Canada Segment
Segment Reporting Information [Line Items]
Net sales	394.5	387.7	1,045.1	1,030.2
Income (loss) before income taxes	2.2	2.3	6.3	3.4
Interest expense	0.1	0.2	0.6	0.7
Depreciation and amortization	0.6	0.7	1.8	1.9
Capital expenditures	0.5	0.6	1.4	1.6
Corporate
Segment Reporting Information [Line Items]
Net sales	11.6	15.2	30.6	28.1
Income (loss) before income taxes	(7.6)	(6.9)	(15.2)	(6.7)
Interest expense	(9.3)	(8.6)	(27.3)	(27.1)
Depreciation and amortization	$ 4.4	$ 3.0	$ 10.1	$ 6.8