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Commitments and Contingencies (Narrative) (Details) $ in Thousands |  |  |  | 6 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | ---
Jul. 29, 2016 defendant | Feb. 09, 2016 defendant | Mar. 11, 1997 | Jul. 29, 2016 claim | Dec. 31, 1997 USD ($) well | Mar. 31, 2017 USD ($) well | Mar. 31, 2016 USD ($)
Commitments [Line Items] |  |  |  |  |  |  |
Plugging and abandonment escrow account on the WCBB properties (Note 10) |  |  |  |  |  | $ 3,100 |
Number of claims filed | claim |  |  |  | 2 |  |  |
Judicial District Court for the Parish of Cameron |  |  |  |  |  |  |
Commitments [Line Items] |  |  |  |  |  |  |
Number of defendants | defendant |  | 26 |  |  |  |  |
Judicial District Court for the Parish of Vermillion |  |  |  |  |  |  |
Commitments [Line Items] |  |  |  |  |  |  |
Number of defendants | defendant | 40 |  |  |  |  |  |
WCBB |  |  |  |  |  |  |
Commitments [Line Items] |  |  |  |  |  |  |
Purchasing remaining percent interest In oil and gas property, percent |  |  |  |  | 50.00% |  |
Payments held for restricted cash |  |  |  |  | $ 18 |  |
Significant plugging commitment minimum number of wells to be plugged | well |  |  |  |  | 20 |  |
Tenure of minimum wells to be plugged |  |  | 20 years |  |  |  |
Number of wells plugged | well |  |  |  |  |  | 513 |
Loss on long-term purchase commitment | Muskie Proppant LLC |  |  |  |  |  |  |
Commitments [Line Items] |  |  |  |  |  |  |
Long-term purchase commitment, accrued damages , amount |  |  |  |  |  | $ 0 | $ 1,300

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