Other Noncurrent Liabilities (Components of Noncurrent Liabilities) (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Pension and retiree medical obligations	$ 87,101	$ 90,584
Liability for uncertain tax positions	4,064	2,471
Deferred revenue	3,692	4,612
Other	18,399	16,610
Total other noncurrent liabilities	$ 113,256	$ 114,277