Segment and Geographic Information - Geographic Reporting Segments Table (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net sales: [Abstract]
Net sales	$ 2,287.3	$ 2,039.8	$ 4,388.0	$ 3,762.3
Income (loss) before income taxes: [Abstract]
Income (loss) before income taxes	17.1	14.4	22.9	15.7
Interest expense: [Abstract]
Interest expense	0.6	0.6	1.2	1.2
Depreciation and amortization: [Abstract]
Depreciation and amortization	6.4	5.6	12.7	10.7
United States
Net sales: [Abstract]
Net sales	1,984.4	1,710.3	3,802.9	3,161.9
Income (loss) before income taxes: [Abstract]
Income (loss) before income taxes	15.5	17.5	19.0	19.9
Interest expense: [Abstract]
Interest expense	7.0	5.5	13.4	10.5
Depreciation and amortization: [Abstract]
Depreciation and amortization	4.4	3.8	8.7	7.4
Canada
Net sales: [Abstract]
Net sales	295.2	320.5	569.8	589.8
Income (loss) before income taxes: [Abstract]
Income (loss) before income taxes	0.7	(0.8)	0.9	(2.1)
Interest expense: [Abstract]
Interest expense	0.2	0.2	0.4	0.5
Depreciation and amortization: [Abstract]
Depreciation and amortization	0.8	0.8	1.5	1.5
Corporate adjustments and eliminations
Net sales: [Abstract]
Net sales	7.7	9.0	15.3	10.6
Income (loss) before income taxes: [Abstract]
Income (loss) before income taxes	0.9	(2.3)	3.0	(2.1)
Interest expense: [Abstract]
Interest expense	(6.6)	(5.1)	(12.6)	(9.8)
Depreciation and amortization: [Abstract]
Depreciation and amortization	$ 1.2	$ 1.0	$ 2.5	$ 1.8