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

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- Definition

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Derivatives (Currency Contracts) (Details) $ in Thousands, CAD in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 CAD	Dec. 31, 2016 CAD
Derivative [Line Items]
Gain (loss) on derivatives not designated as hedging instruments	$ 0	$ 31	$ 0	$ (387)
Other Income (Expense) \| Currency Contracts
Derivative [Line Items]
Gain (loss) on derivatives not designated as hedging instruments	$ 0	$ 31	$ 0	$ (387)
Not Designated as Hedging Instrument \| Currency Contracts
Derivative [Line Items]
Derivative, Notional Amount \| CAD					CAD 0.0	CAD 0.0