Business and Geographic Segments - Net Sales by Point of Origin and Point of Destination (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net sales	$ 324.8	$ 383.2	$ 408.8	$ 416.1	$ 432.0	$ 476.5	$ 491.7	$ 462.4	$ 1,532.9	$ 1,862.6	$ 1,863.6
Point Of Origin
Segment Reporting Information [Line Items]
Net sales									1,532.9	1,862.6	1,863.6
Point Of Destination
Segment Reporting Information [Line Items]
Net sales									1,532.9	1,862.6	1,863.6
United States | Point Of Origin
Segment Reporting Information [Line Items]
Net sales									841.9	993.7	961.5
Germany | Point Of Origin
Segment Reporting Information [Line Items]
Net sales									690.0	844.1	915.8
Canada | Point Of Origin
Segment Reporting Information [Line Items]
Net sales									216.9	252.3	246.5
Belgium | Point Of Origin
Segment Reporting Information [Line Items]
Net sales									198.8	249.3	254.6
Norway | Point Of Origin
Segment Reporting Information [Line Items]
Net sales									183.5	256.8	261.3
North America | Point Of Destination
Segment Reporting Information [Line Items]
Net sales									604.0	753.2	690.5
Europe | Point Of Destination
Segment Reporting Information [Line Items]
Net sales									700.9	883.6	905.0
Asia and other | Point Of Destination
Segment Reporting Information [Line Items]
Net sales									228.0	225.8	268.1
Geography Eliminations | Point Of Origin
Segment Reporting Information [Line Items]
Net sales									$ (598.2)	$ (733.6)	$ (776.1)