Derivatives And Risk Management (Foreign Currency Exchange Contracts) (Details) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 United States of America, Dollars [Member] USD ($)	Dec. 31, 2012 United States of America, Dollars [Member] USD ($)	Jun. 30, 2013 Canada, Dollars [Member] CAD	Dec. 31, 2012 Canada, Dollars [Member] CAD
Intercompany Foreign Currency Balance [Line Items]
Notional amount			$ 7,682	$ 12,621	7,938	12,502
Number of contracts	26	20
Number of days Canadian currency prices are settled with U.S. dollars	60 days

Number of foreign currency exchange rate derivatives held by the entity at the reporting date.

Reference 1: 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 2: 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 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant