Derivative Instruments - Financial Information Related to Cash Flow Hedges of Future Revenues (Detail) (Cash Flow Hedging [Member]) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2013 Foreign Exchange Forward [Member] EUR (€)	Dec. 31, 2012 Foreign Exchange Forward [Member] EUR (€)
Derivative [Line Items]
Notional balance of outstanding contracts versus the dollar				€ 85,627	€ 88,680
Hedge effectiveness	100.00%	100.00%
Net gains and (losses) included in revenue	$ (4,294)	$ 4,201	$ (4,159)

Nominal or face amount used to calculate payments on the derivative asset.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5579245-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104

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Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant