Fair Value Measurements - Financial Assets and Liabilities Measured on a Recurring Basis at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Mutual fund assets	$ 19,362	$ 20,217
Derivative assets:
Foreign currency contracts	164	73
Total assets at fair value	19,526	20,290
Derivative liabilities:
Foreign currency contracts	106	628
Interest rate contracts	50
Total liabilities at fair value	156
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Mutual fund assets	19,362	20,217
Derivative assets:
Total assets at fair value	19,362	20,217
Level 2 [Member]
Derivative assets:
Foreign currency contracts	164	73
Total assets at fair value	164	73
Derivative liabilities:
Foreign currency contracts	106	$ 628
Interest rate contracts	50
Total liabilities at fair value	$ 156