Inventories (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Major classes of inventories    
Finished goods $ 196.8 $ 197.4
Service parts 135.2 125.6
Raw materials and work in process 90.5 82.2
Total inventories $ 422.5 $ 405.2