Segment and Geographic Information - Geographic Reporting Segments (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Net sales	$ 3,836.8	$ 3,993.9	$ 3,687.4	$ 3,011.3	$ 2,815.1	$ 2,991.6	$ 2,810.4	$ 2,452.3	$ 14,529.4	$ 11,069.4	$ 10,280.1
Income (loss) before income taxes	29.7	20.2	26.4	9.2	28.2	24.2	21.4	9.1	85.5	82.9	66.4
Interest expense	2.0	1.5	1.0	0.8	0.6	0.6	0.7	0.6	5.3	2.5	2.4
Depreciation and amortization	11.7	11.4	10.2	9.6	9.6	9.9	9.7	8.7	42.9	37.9	32.0
Capital expenditures	$ 9.8	$ 21.7	$ 14.0	$ 8.8	$ 5.6	$ 10.3	$ 11.7	$ 2.7	54.3	30.3	53.9
Reportable Geographical Components | United States
Segment Reporting Information [Line Items]
Net sales									13,133.0	9,829.7	8,989.0
Income (loss) before income taxes									90.7	79.4	70.8
Interest expense									40.8	35.0	32.0
Depreciation and amortization									31.0	29.3	24.9
Capital expenditures									52.4	28.6	53.3
Reportable Geographical Components | Canada
Segment Reporting Information [Line Items]
Net sales									1,356.4	1,203.5	1,250.9
Income (loss) before income taxes									6.4	1.7	3.2
Interest expense									1.1	0.7	0.7
Depreciation and amortization									2.5	2.4	2.8
Capital expenditures									1.9	1.7	0.6
Intersegment Eliminations
Segment Reporting Information [Line Items]
Interest expense									(36.6)	(33.2)	(30.3)
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Net sales									40.0	36.2	40.2
Income (loss) before income taxes									(11.6)	1.8	(7.6)
Depreciation and amortization									$ 9.4	$ 6.2	$ 4.3