Components of Working Capital - Other Current Assets Table (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Current Assets [Line Items]
Natural gas liquids inventory	$ 10,788	$ 7,126
Imbalance receivables	1,640	3,483
Prepaid insurance	2,955	2,889
Total other current assets	$ 15,383	$ 13,498

Carrying amount as of the balance sheet date of liquid hydrocarbon components recovered from natural gas.

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The value of gas balancing asset or liability as of the end of the period.

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Amount of asset related to consideration paid in advance for insurance that provides economic benefits within a future period of one year or the normal operating cycle, if longer.

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