Derivative Instruments And Hedging Activities (Narrative) (Details) (USD $) In Millions	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Derivative Instruments And Hedging Activities
Notional Amount of Foreign Currency Derivatives	$ 208		$ 184
Net cash inflow from settlement of derivative contracts	$ 5.5	$ 6.8

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