Property, Plant and Equipment - Components of property, plant and equipment (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment
Total cost	$ 722.9	$ 789.6
Less accumulated depreciation	(428.0)	(480.8)
Property, plant and equipment-net	294.9	308.8
Land
Property, Plant and Equipment
Total cost	25.4	23.6
Building and Improvements
Property, Plant and Equipment
Total cost	196.4	225.0
Machinery, Equipment and Tooling
Property, Plant and Equipment
Total cost	263.6	292.6
Furniture and Fixtures
Property, Plant and Equipment
Total cost	15.6	16.7
Computer Hardware and Software
Property, Plant and Equipment
Total cost	114.4	126.0
Rental Cranes
Property, Plant and Equipment
Total cost	90.2	89.0
Property, plant and equipment-net	54.3	57.9
Construction in Progress
Property, Plant and Equipment
Total cost	$ 17.3	$ 16.7