Schedule of Other Noncurrent Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Schedule of Other Liabilities [Line Items]
Pension and retiree medical obligations	$ 85,698	$ 91,542
Liability for uncertain tax positions	3,574	5,262
Deferred revenue	5,657	3,198
Contingent consideration for acquisition .	5,515
Other	13,373	15,844
Total other noncurrent liabilities	$ 113,817	$ 115,846