Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Assets:
Short-term investments	$ 7.5		$ 12.4
Deferred compensation assets	4.8		4.0
Total assets at fair value	12.3		16.4
Liabilities:
Contingent consideration	3.5		3.3
Deferred compensation liabilities	9.8		7.6
Interest rate swap contracts	6.6		8.6
Foreign currency contracts	3.2		1.4
Long-term debt	400.1		386.0
Total liabilities at fair value	423.2		406.9
Other Financial Instruments [Abstract]
Long-term debt	394.7		378.8
Level 3 Fair Value Measurements [Roll Forward]
Balance, beginning of period	3.3	2.1
Increase in fair value recorded in earnings	0.2	0.4
Balance, end of period	3.5	2.5
Level 1 [Member]
Assets:
Short-term investments	7.5		12.4
Deferred compensation assets	4.8		4.0
Total assets at fair value	12.3		16.4
Liabilities:
Deferred compensation liabilities	9.8		7.6
Total liabilities at fair value	9.8		7.6
Level 2 [Member]
Liabilities:
Interest rate swap contracts	6.6		8.6
Foreign currency contracts	3.2		1.4
Long-term debt	400.1		386.0
Total liabilities at fair value	409.9		396.0
Level 3 [Member]
Liabilities:
Contingent consideration	3.5		3.3
Total liabilities at fair value	$ 3.5		$ 3.3