Fair Value of Financial Instruments (Details) (USD $) In Millions	9 Months Ended
	Sep. 30, 2011	Dec. 31, 2010
Assets: [Abstract]
Short-term investments	$ 23.6	$ 0.6
Deferred compensation assets	3.1	3.6
Foreign currency contracts	0.2
Commodity contracts	0.2
Total assets at fair value	27.1	4.2
Liabilities: [Abstract]
Contingent consideration liability	1.9	2.3
Deferred compensation liabilities	4.4	5.4
Interest rate swap contracts	9.2	6.1
Total liabilities at fair value	15.5	13.8
Level 3 Fair Value Measurements [Roll Forward]
Beginning Balance	2.3
Increase in fair value recorded in earnings	0.4
Reduction in fair value recorded in earnings	(0.8)
Ending Balance	1.9
Other Financial Instruments [Abstract]
Fair value of long-term debt	302.7	344.2
Carrying amount of long-term debt	323.3	358.1
Level 1 [Member]
Assets: [Abstract]
Short-term investments	23.6	0.6
Deferred compensation assets	3.1	3.6
Total assets at fair value	26.7	4.2
Liabilities: [Abstract]
Deferred compensation liabilities	4.4	5.4
Total liabilities at fair value	4.4	5.4
Level 2 [Member]
Assets: [Abstract]
Foreign currency contracts	0.2
Commodity contracts	0.2
Total assets at fair value	0.4	0
Liabilities: [Abstract]
Interest rate swap contracts	9.2	6.1
Total liabilities at fair value	9.2	6.1
Level 3 [Member]
Liabilities: [Abstract]
Contingent consideration liability	1.9	2.3
Total liabilities at fair value	$ 1.9	$ 2.3