Summary Of Significant Accounting Policies (Rollforward Analysis Of The Allowance Against Accounts Receivable Balance) (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
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| Allowance for Bad Debt, Balance at January 1 | $ (4,221) | $ (2,400) | |
| Allowance for Bad Debt, Charged to costs and expenses | (1,222) | (2,699) | $ (2,400) |
| Allowance for Bad Debts, Foreign currency gain (loss) | 232 | 878 | |
| Allowance for Bad Debt, Balance at December 31 | (5,211) | (4,221) | (2,400) |
| Gabon [Member] | |||
| Allowance for Bad Debt, Charged to costs and expenses | $ (700) | $ (2,700) | $ (2,400) |
| X | ||||||||||
- Definition Allowance For Bad Debts, Foreign Currency Gain No definition available.
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- Definition For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of expense related to write-down of receivables to the amount expected to be collected. Includes, but is not limited to, accounts receivable and notes receivable. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Details
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