Business and Geographic Segments - Net Property and Equipment by Segment (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net property and equipment:
Net property and equipment	$ 665.7	$ 733.6	$ 796.4
United States
Net property and equipment:
Net property and equipment	227.1	234.4	232.8
Germany
Net property and equipment:
Net property and equipment	229.9	259.5	292.9
Canada
Net property and equipment:
Net property and equipment	55.0	63.4	67.1
Norway
Net property and equipment:
Net property and equipment	71.9	85.5	100.9
Belgium
Net property and equipment:
Net property and equipment	$ 81.8	$ 90.8	$ 102.7