Financial Instruments (Details) (EUR €) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012
Financial Instruments [Abstract]
Term of foreign exchange forward contract, maximum (in years)	1Y
Notional amount of foreign exchange forward contract	€ 55

Aggregate notional amount of foreign currency exchange rate derivatives. Notional amount refers to the number of currency units specified in the foreign currency derivative contract.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

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

Name:	us-gaap_NotionalAmountOfForeignCurrencyDerivatives
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant