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v3.21.1

INVESTMENTS - (Details) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2020 USD ($)
Investments rollforward |
Proceeds from sale of investments | $ 112
Marketable equity securities |
Investments rollforward |
Proceeds from sale of investments | $ 100

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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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Namespace Prefix: | mux_
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Balance Type: | na
Period Type: | duration

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- Definition The cash inflow associated with the aggregate amount received by the entity through sale or maturity of marketable securities (held-to-maturity or available-for-sale) during the period. + References No definition available. + Details
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Period Type: | duration

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |