Segment and Geographic Information - Geographic Reporting Segments Table (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Net sales: [Abstract]
Net sales	$ 2,314.9	$ 2,225.1	$ 6,702.9	$ 5,987.4
Income (loss) before income taxes: [Abstract]
Income (loss) before income taxes	16.9	19.3	39.7	35.0
Interest expense: [Abstract]
Interest expense	0.4	0.6	1.6	1.8
Depreciation and amortization: [Abstract]
Depreciation and amortization	6.3	5.4	19.0	16.1
United States
Net sales: [Abstract]
Net sales	1,995.6	1,874.5	5,798.5	5,036.4
Income (loss) before income taxes: [Abstract]
Income (loss) before income taxes	10.3	20.0	29.3	39.9
Interest expense: [Abstract]
Interest expense	6.6	5.9	20.0	16.4
Depreciation and amortization: [Abstract]
Depreciation and amortization	4.4	3.6	13.1	11.0
Canada
Net sales: [Abstract]
Net sales	311.2	340.5	881.0	930.3
Income (loss) before income taxes: [Abstract]
Income (loss) before income taxes	0.7	0.4	1.6	(1.7)
Interest expense: [Abstract]
Interest expense	0.1	0.2	0.5	0.7
Depreciation and amortization: [Abstract]
Depreciation and amortization	0.7	0.7	2.2	2.2
Corporate adjustments and eliminations
Net sales: [Abstract]
Net sales	8.1	10.1	23.4	20.7
Income (loss) before income taxes: [Abstract]
Income (loss) before income taxes	5.9	(1.1)	8.8	(3.2)
Interest expense: [Abstract]
Interest expense	(6.3)	(5.5)	(18.9)	(15.3)
Depreciation and amortization: [Abstract]
Depreciation and amortization	$ 1.2	$ 1.1	$ 3.7	$ 2.9