Other Noncurrent Liabilities (Components of Noncurrent Liabilities) (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Pension and retiree medical obligations	$ 85,289	$ 90,584
Liability for uncertain tax positions	4,014	2,471
Deferred revenue	3,486	4,612
Other	18,509	16,610
Total other noncurrent liabilities	$ 111,298	$ 114,277