Accounting Policies - Investments in Affiliated Companies (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Revenue			$ 9,088
Gross profit			3,489
Net income			2,413
Equity in earnings of affiliated companies	$ 0	$ 0	$ 570

No definition available.

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The amount of gross profit (loss) reported by an equity method investment of the entity.

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The amount of net income (loss) reported by an equity method investment of the entity.

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The amount of revenue from sale of goods and services reduced by sales returns, allowances, and discounts reported by an equity method investment of the entity.

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