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Summary of Significant Accounting Policies (Narrative) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segment	Jun. 30, 2019 USD ($)
Revenue from External Customer [Line Items]
Revenues	$ 17,405	$ 19,895	$ 35,295	$ 37,886
Number of operating segments \| segment			1
Minimum
Revenue from External Customer [Line Items]
Amortization period of capitalized contract costs	1 year		1 year
Property and equipment, estimated useful life			3 years
Minimum \| Rental Contracts, Excluding Large Horsepower Compressors
Revenue from External Customer [Line Items]
Rental contract term	6 months		6 months
Maximum
Revenue from External Customer [Line Items]
Property and equipment, estimated useful life			39 years
Maximum \| Rental Contracts, Excluding Large Horsepower Compressors
Revenue from External Customer [Line Items]
Rental contract term	24 months		24 months
Maximum \| Rental Contracts, Large Horsepower Compressors
Revenue from External Customer [Line Items]
Rental contract term	60 months		60 months
Rental Equipment \| Minimum
Revenue from External Customer [Line Items]
Property and equipment, estimated useful life			15 years
Rental Equipment \| Maximum
Revenue from External Customer [Line Items]
Property and equipment, estimated useful life			25 years
Bill and Hold Arrangement
Revenue from External Customer [Line Items]
Revenues			$ 852,000	$ 6,100