Inventories - Summary of Inventories (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 27, 2013	Dec. 31, 2012
Principally average cost:
Raw materials and supplies	$ 43,645	$ 42,751
Work in process	199,254	203,179
Finished goods	53,386	51,094
Gross inventories	296,285	297,024
Excess of average cost over LIFO inventory value	83,501	90,899
Net inventories	$ 212,784	$ 206,125