Fair Value Measurements - Financial Assets and Liabilities Measured on a Recurring Basis at Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Financial assets and liabilities measured on a recurring basis at fair value
Mutual fund assets	$ 20,134	$ 20,217
Derivative assets:
Foreign currency contracts	131	73
Total assets at fair value	20,265	20,290
Derivative liabilities:
Foreign currency contracts	142	628
Interest rate contracts	60
Total liabilities at fair value	202
Level 1 [Member]
Financial assets and liabilities measured on a recurring basis at fair value
Mutual fund assets	20,134	20,217
Derivative assets:
Total assets at fair value	20,134	20,217
Level 2 [Member]
Derivative assets:
Foreign currency contracts	131	73
Total assets at fair value	131	73
Derivative liabilities:
Foreign currency contracts	142	628
Interest rate contracts	60
Total liabilities at fair value	$ 202