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v3.19.1

Summary Of Significant Accounting Policies (Summary Of Currency Exchange Rates) (Details) | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Australian Dollar [Member] | Spot Rate [Member] |  |  |
Currency Exchange Rates [Line Items] |  |  |
Foreign currency exchange rate | 0.7046 | 0.7815 | 0.7230
Australian Dollar [Member] | Average Rate [Member] |  |  |
Currency Exchange Rates [Line Items] |  |  |
Foreign currency exchange rate | 0.7479 | 0.7670 | 0.7440
New Zealand Dollar [Member] | Spot Rate [Member] |  |  |
Currency Exchange Rates [Line Items] |  |  |
Foreign currency exchange rate | 0.6711 | 0.7100 | 0.6958
New Zealand Dollar [Member] | Average Rate [Member] |  |  |
Currency Exchange Rates [Line Items] |  |  |
Foreign currency exchange rate | 0.6930 | 0.7111 | 0.6973

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