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Summary of Significant Accounting Policies (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
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Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue from contracts with customers |  |  |  |  |  |  |  |  | $ 21,743 | $ 17,712 | $ 21,647
Add: ASC 842 rental revenue |  |  |  |  |  |  |  |  | 56,701 | 47,766 | 46,046
Total revenue | $ 19,706 | $ 20,852 | $ 19,895 | $ 17,991 | $ 16,160 | $ 16,396 | $ 18,204 | $ 14,718 | 78,444 | 65,478 | 67,693
Compressors - sales |  |  |  |  |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue from contracts with customers |  |  |  |  |  |  |  |  | 15,185 | 10,994 | 13,382
Flares - sales |  |  |  |  |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue from contracts with customers |  |  |  |  |  |  |  |  | 959 | 2,535 | 2,755
Other (Parts/Rebuilds) - sales |  |  |  |  |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue from contracts with customers |  |  |  |  |  |  |  |  | 3,619 | 2,740 | 4,071
Service and maintenance |  |  |  |  |  |  |  |  |  |  |
Disaggregation of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Revenue from contracts with customers |  |  |  |  |  |  |  |  | $ 1,980 | $ 1,443 | $ 1,439

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