Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Assets:
Short-term investments	$ 11.7	$ 7.5
Deferred compensation assets	5.8	5.7
Foreign currency contracts	0.1
Total assets at fair value	17.6	13.2
Liabilities:
Contingent consideration	4.7	4.3
Deferred compensation liabilities	10.3	12.1
Interest rate swap contracts	5.1	5.6
Foreign currency contracts	0.3
Total liabilities at fair value	20.4	22.0
Level 1 [Member]
Assets:
Short-term investments	11.7	7.5
Deferred compensation assets	5.8	5.7
Total assets at fair value	17.5	13.2
Liabilities:
Deferred compensation liabilities	10.3	12.1
Total liabilities at fair value	10.3	12.1
Level 2 [Member]
Assets:
Foreign currency contracts	0.1
Total assets at fair value	0.1
Liabilities:
Interest rate swap contracts	5.1	5.6
Foreign currency contracts	0.3
Total liabilities at fair value	5.4	5.6
Level 3 [Member]
Liabilities:
Contingent consideration	4.7	4.3
Total liabilities at fair value	$ 4.7	$ 4.3