Segment and Geographic Information - Information by Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Net sales	$ 4,263.9	$ 4,339.0	$ 8,203.2	$ 8,093.1
Income before income taxes:	22.6	24.2	28.7	26.0
Interest expense, net	2.8	3.2	6.3	6.6
Depreciation and amortization	16.7	15.5	32.4	30.9
Capital expenditures:	4.8	4.1	9.8	9.2
Interest income	0.1	0.1	0.2	0.2
Operating Segment | United States
Segment Reporting Information [Line Items]
Net sales	3,860.0	3,934.5	7,439.6	7,348.9
Income before income taxes:	26.0	31.3	35.2	40.6
Interest expense, net	15.3	12.8	29.9	25.8
Depreciation and amortization	11.0	10.9	21.8	21.4
Capital expenditures:	3.8	3.5	8.2	8.5
Operating Segment | Canada
Segment Reporting Information [Line Items]
Net sales	394.6	390.1	743.0	716.7
Income before income taxes:	1.8	2.1	4.3	3.9
Interest expense, net	(0.2)	0.3	0.3	0.8
Depreciation and amortization	0.8	0.6	1.6	1.2
Capital expenditures:	1.0	0.6	1.6	0.7
Corporate
Segment Reporting Information [Line Items]
Net sales	9.3	14.4	20.6	27.5
Income before income taxes:	(5.2)	(9.2)	(10.8)	(18.5)
Interest expense, net	(12.3)	(9.9)	(23.9)	(20.0)
Depreciation and amortization	$ 4.9	$ 4.0	$ 9.0	$ 8.3