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Rental Equipment, Property and Equipment - Schedule of Rental Equipment (Details) - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Property, Plant and Equipment [Line Items] |  |
Rental equipment | $ 379,548 | $ 383,387
Accumulated depreciation | (172,563) | (175,802)
Rental equipment, net of accumulated depreciation | 206,985 | 207,585
Rental Compressor Unit |  |
Property, Plant and Equipment [Line Items] |  |
Rental equipment | 374,336 | 379,623
Work-in-progress |  |
Property, Plant and Equipment [Line Items] |  |
Rental equipment | $ 5,212 | $ 3,764

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- Definition Rental Equipment, Accumulated Depreciation + References No definition available. + Details
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- Definition Rental Equipment, Gross + References No definition available. + Details
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Namespace Prefix: | ngs_
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Balance Type: | debit
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- Definition Rental Equipment, Net + References No definition available. + Details
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Balance Type: | debit
Period Type: | instant

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Details
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- Details
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Namespace Prefix: |
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Balance Type: |
Period Type: |