Other Noncurrent Liabilities (Components of Noncurrent Liabilities) (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Pension and retiree medical obligations	$ 98,656	$ 93,604
Liability for uncertain tax positions	2,079	2,623
Deferred revenue	2,361	2,442
Other	19,208	22,561
Total other noncurrent liabilities	$ 122,304	$ 121,230