Goodwill and Other Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Goodwill.
Balance at beginning of period	$ 100.2	$ 98.3
Acquisitions	10.5	4.7
Impairment of assets	1.4
Dispositions		(0.1)
Current period adjustments	6.1	(2.0)
Foreign currency impact	0.5	(0.7)
Balance at end of period	$ 115.9	$ 100.2