Other Noncurrent Liabilities (Components of Noncurrent Liabilities) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Other Liabilities Disclosure [Abstract]
Pension and retiree medical obligations	$ 98,422	$ 76,190
Liability for uncertain tax positions	3,030	4,252
Deferred revenue	1,828	3,763
Other	16,795	18,160
Total other noncurrent liabilities	$ 120,075	$ 102,365