Segment and Geographic Information - Information by Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Net sales	$ 4,502.6	$ 4,422.6	$ 12,705.8	$ 12,515.7
Income before income taxes	32.2	30.6	60.9	56.6
Interest expense, net	2.1	4.2	8.4	10.8
Depreciation and amortization	16.5	14.9	48.9	45.8
Capital expenditures:	8.1	6.1	17.9	15.3
Interest income	0.1	0.1	0.2	0.3
Operating Segment | United States
Segment Reporting Information [Line Items]
Net sales	4,059.1	3,999.3	11,498.7	11,348.2
Income before income taxes	42.9	33.5	78.2	74.1
Interest expense, net	14.1	15.6	44.0	41.4
Depreciation and amortization	12.1	10.6	33.9	32.0
Capital expenditures:	7.9	5.4	16.1	13.9
Operating Segment | Canada
Segment Reporting Information [Line Items]
Net sales	431.6	415.7	1,174.6	1,132.4
Income before income taxes	5.0	3.8	9.2	7.7
Interest expense, net	0.1	0.2	0.4	1.0
Depreciation and amortization	0.9	0.7	2.5	1.9
Capital expenditures:	0.2	0.7	1.8	1.4
Corporate
Segment Reporting Information [Line Items]
Net sales	11.9	7.6	32.5	35.1
Income before income taxes	(15.7)	(6.7)	(26.5)	(25.2)
Interest expense, net	(12.1)	(11.6)	(36.0)	(31.6)
Depreciation and amortization	$ 3.5	$ 3.6	$ 12.5	$ 11.9