Fair Value Measurements - Financial Assets and Liabilities Measured on a Recurring Basis at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Mutual fund assets	$ 23,162	$ 20,910
Derivative assets:
Foreign currency contracts	450	112
Total assets at fair value	23,612	21,022
Derivative liabilities:
Foreign currency contracts	388	305
Interest rate contracts	82	53
Total liabilities at fair value	470	358
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Mutual fund assets	23,162	20,910
Derivative assets:
Total assets at fair value	23,162	20,910
Level 2 [Member]
Derivative assets:
Foreign currency contracts	450	112
Total assets at fair value	450	112
Derivative liabilities:
Foreign currency contracts	388	305
Interest rate contracts	82	53
Total liabilities at fair value	$ 470	$ 358