Employee Benefit Plans - Amounts Recognized in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Other long-term asset	$ 6,721	$ 3,336
Pension and other post-retirement liabilities	(341,510)	(284,235)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Other long-term asset	6,721	3,336
Other current liability	(8,206)	(7,432)
Pension and other post-retirement liabilities	(339,872)	(282,524)
Amounts recognized in consolidated balance sheets	$ (341,357)	$ (286,620)