Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Assets:
Short-term investments	$ 8.5	$ 7.5
Deferred compensation assets	6.1	5.7
Foreign currency contracts	0.1
Total assets at fair value	14.7	13.2
Liabilities:
Contingent consideration	4.9	4.3
Deferred compensation liabilities	7.7	7.8
Interest rate swap contracts	4.7	5.6
Foreign currency contracts	0.1
Total liabilities at fair value	17.4	17.7
Level 1 [Member]
Assets:
Short-term investments	8.5	7.5
Deferred compensation assets	6.1	5.7
Total assets at fair value	14.6	13.2
Liabilities:
Deferred compensation liabilities	7.7	7.8
Total liabilities at fair value	7.7	7.8
Level 2 [Member]
Assets:
Foreign currency contracts	0.1
Total assets at fair value	0.1
Liabilities:
Interest rate swap contracts	4.7	5.6
Foreign currency contracts	0.1
Total liabilities at fair value	4.8	5.6
Level 3 [Member]
Liabilities:
Contingent consideration	4.9	4.3
Total liabilities at fair value	$ 4.9	$ 4.3