Derivative Instruments and Hedging Activities - Additional Information (Detail) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2013 Forward contracts [Member] USD ($)	Mar. 31, 2013 Forward contracts [Member] EUR (€)	Mar. 31, 2013 Swaps [Member] USD ($)	Mar. 31, 2013 Swaps [Member] EUR (€)
Derivative [Line Items]
Derivative, notional amount		$ 6.3	€ 4.9	$ 2.4	€ 1.8
Maximum time frame for our derivatives	The maximum time frame for our derivatives is currently less than twelve months.

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant