- Fair Value Measurements (Detail) - Fair value, measurements, recurring - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-qualified deferred compensation assets	$ 54,244	$ 49,330
Foreign exchange contracts, net		298
Total assets at fair value	54,244	49,628
Commodity contracts, net		0
Non-qualified deferred compensation liabilities	(54,244)	(49,330)
Foreign exchange contracts, net	(426)
Total liabilities at fair value	(54,670)	(49,330)
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-qualified deferred compensation assets	54,244	49,330
Foreign exchange contracts, net		0
Total assets at fair value	54,244	49,330
Commodity contracts, net		0
Non-qualified deferred compensation liabilities	(54,244)	(49,330)
Total liabilities at fair value	(54,244)	(49,330)
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-qualified deferred compensation assets	0	0
Foreign exchange contracts, net		298
Total assets at fair value	0	298
Commodity contracts, net		0
Non-qualified deferred compensation liabilities	0	0
Foreign exchange contracts, net	(426)
Total liabilities at fair value	(426)	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-qualified deferred compensation assets	0	0
Foreign exchange contracts, net		0
Total assets at fair value	0	0
Commodity contracts, net		0
Non-qualified deferred compensation liabilities	0	0
Total liabilities at fair value	$ 0	$ 0