Business and Geographic Segments - Net Property and Equipment by Segment (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net property and equipment:
Net property and equipment	$ 654.5	$ 665.7	$ 733.6
United States
Net property and equipment:
Net property and equipment	214.7	227.1	234.4
Germany
Net property and equipment:
Net property and equipment	223.7	229.9	259.5
Canada
Net property and equipment:
Net property and equipment	60.5	55.0	63.4
Norway
Net property and equipment:
Net property and equipment	75.5	71.9	85.5
Belgium
Net property and equipment:
Net property and equipment	$ 80.1	$ 81.8	$ 90.8