Fair Value Measurements (Fair Value of Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Assets:
Short-term investments	$ 12.4	$ 26.5
Deferred compensation assets	4.0	3.3
Total assets at fair value	16.4	29.8
Liabilities:
Contingent consideration	3.3	2.1
Deferred compensation liabilities	7.6	4.6
Interest rate swap contracts	8.6	8.8
Foreign currency contracts	1.4
Long-term debt	386.0	279.2
Total liabilities at fair value	406.9	294.7
Other Financial Instruments [Abstract]
Long-term debt	378.8	299.3
Level 1 [Member]
Assets:
Short-term investments	12.4	26.5
Deferred compensation assets	4.0	3.3
Total assets at fair value	16.4	29.8
Liabilities:
Contingent consideration	0	0
Deferred compensation liabilities	7.6	4.6
Interest rate swap contracts	0	0
Foreign currency contracts	0
Long-term debt	0	0
Total liabilities at fair value	7.6	4.6
Level 2 [Member]
Assets:
Short-term investments	0	0
Deferred compensation assets	0	0
Total assets at fair value	0	0
Liabilities:
Contingent consideration	0	0
Deferred compensation liabilities	0	0
Interest rate swap contracts	8.6	8.8
Foreign currency contracts	1.4
Long-term debt	386.0	279.2
Total liabilities at fair value	396.0	288.0
Level 3 [Member]
Assets:
Short-term investments	0	0
Deferred compensation assets	0	0
Total assets at fair value	0	0
Liabilities:
Contingent consideration	3.3	2.1
Deferred compensation liabilities	0	0
Interest rate swap contracts	0	0
Foreign currency contracts	0
Long-term debt	0	0
Total liabilities at fair value	$ 3.3	$ 2.1