Segment Information (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
Segment Information [Line Items]
Net sales	$ 2,584.7	$ 2,412.1	$ 4,903.9	$ 4,541.7
Income from operations	136.4	128.2	240.0	219.9
Depreciation and amortization expense	(53.2)	(50.8)	(105.7)	(102.4)
Corporate [Member]
Segment Information [Line Items]
Net sales	1,394.4	1,338.4	2,757.2	2,617.7
Income from operations	92.3	87.7	177.1	166.0
Depreciation and amortization expense	(24.4)	(24.4)	(48.7)	(48.7)
Public [Member]
Segment Information [Line Items]
Net sales	1,040.4	951.2	1,858.0	1,675.1
Income from operations	66.1	61.0	108.2	98.1
Depreciation and amortization expense	(11.0)	(11.0)	(22.0)	(22.0)
Other [Member]
Segment Information [Line Items]
Net sales	149.9	122.5	288.7	248.9
Income from operations	5.0	4.4	7.5	8.0
Depreciation and amortization expense	(2.4)	(2.2)	(4.7)	(4.4)
Headquarters [Member]
Segment Information [Line Items]
Net sales	0	0	0	0
Income from operations	(27.0)	(24.9)	(52.8)	(52.2)
Depreciation and amortization expense	$ (15.4)	$ (13.2)	$ (30.3)	$ (27.3)