Comprehensive Income (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Comprehensive income (loss)
Net income	$ 32.9	$ 21.1	$ 79.2	$ 61.3
Other comprehensive income, net of taxes:
Foreign currency translation gain (loss)	(56.4)	44.3	(16.9)	(28.2)
Unrealized (loss) gain on securities	(0.2)	0.1	(0.6)	0.8
Unrealized (loss) gain on derivative instruments	(1.0)	0	6.8	(4.5)
Post-retirement benefit plans	0.9	0.2	2.8	2.0
Comprehensive income (loss)	$ (23.8)	$ 65.7	$ 71.3	$ 31.4