Notional Amounts of Company's Outstanding Foreign Currency Forward Contracts by Currency (Detail) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Intercompany Foreign Currency Balance [Line Items]
Notional amounts of foreign currency forward contracts	$ 72,224	$ 66,802
Euro
Intercompany Foreign Currency Balance [Line Items]
Notional amounts of foreign currency forward contracts	28,512	41,022
Swedish Kronor
Intercompany Foreign Currency Balance [Line Items]
Notional amounts of foreign currency forward contracts	26,400	23,212
British Pound Sterling
Intercompany Foreign Currency Balance [Line Items]
Notional amounts of foreign currency forward contracts	16,412	1,551
Australian Dollar
Intercompany Foreign Currency Balance [Line Items]
Notional amounts of foreign currency forward contracts	718	1,017
Danish Kroner
Intercompany Foreign Currency Balance [Line Items]
Notional amounts of foreign currency forward contracts	$ 182