Business and Geographic Segments - Net Sales by Point of Origin and Point of Destination (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Net sales	$ 400.1	$ 448.2	$ 516.1	$ 499.2	$ 427.4	$ 508.7	$ 568.4	$ 582.8	$ 1,863.6	$ 2,087.3	$ 2,025.1
Point Of Origin
Segment Reporting Information [Line Items]
Net sales									1,863.6	2,087.3	2,025.1
Point Of Destination
Segment Reporting Information [Line Items]
Net sales									1,863.6	2,087.3	2,025.1
United States | Point Of Origin
Segment Reporting Information [Line Items]
Net sales									961.5	1,153.8	831.4
Germany | Point Of Origin
Segment Reporting Information [Line Items]
Net sales									915.8	977.7	1,039.7
Canada | Point Of Origin
Segment Reporting Information [Line Items]
Net sales									246.5	339.1	301.7
Norway | Point Of Origin
Segment Reporting Information [Line Items]
Net sales									261.3	284.0	245.1
Belgium | Point Of Origin
Segment Reporting Information [Line Items]
Net sales									254.6	272.9	301.8
Eliminations | Point Of Origin
Segment Reporting Information [Line Items]
Net sales									(776.1)	(940.2)	(694.6)
North America | Point Of Destination
Segment Reporting Information [Line Items]
Net sales									690.5	760.7	578.2
Europe | Point Of Destination
Segment Reporting Information [Line Items]
Net sales									905.0	1,011.4	1,141.3
Asia and other | Point Of Destination
Segment Reporting Information [Line Items]
Net sales									$ 268.1	$ 315.2	$ 305.6