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Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Revenue from External Customer [Line Items]
Revenues	$ 18,397	$ 17,890
Minimum
Revenue from External Customer [Line Items]
Amortization period of capitalized contract costs	1 year
Minimum \| Rental Contracts, Excluding Large Horsepower Compressors
Revenue from External Customer [Line Items]
Rental contract term	6 months
Maximum \| Rental Contracts, Excluding Large Horsepower Compressors
Revenue from External Customer [Line Items]
Rental contract term	24 months
Maximum \| Rental Contracts, Large Horsepower Compressors
Revenue from External Customer [Line Items]
Rental contract term	60 months
Sales
Revenue from External Customer [Line Items]
Revenues	$ 2,711	1,450
Revenue recognized	1,100		$ 500
Rental income
Revenue from External Customer [Line Items]
Revenue recognized	2		$ 73
Bill and Hold Arrangement
Revenue from External Customer [Line Items]
Revenues	$ 0	$ 900