Inventories (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Inventories
Raw materials	$ 172.5		$ 172.5		$ 189.7
Work-in-process	199.2		199.2		196.5
Finished goods	149.2		149.2		155.3
Demonstration units	45.9		45.9		48.3
Inventories	566.8		566.8		589.8
Inventory-in-transit	78.8		78.8		81.9
Write-down of demonstration units	$ 7.4	$ 8.0	$ 22.6	$ 24.0