Long-Lived Asset Impairment (Details) - Idle compressor units hp in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) compressor_unit hp	Mar. 31, 2017 USD ($) compressor_unit hp
Impaired Long-Lived Assets Held and Used
Idle compressor units retired from the active fleet (compressors) | compressor_unit	45	80
Horsepower of idle compressor units retired from the active fleet (horsepower) | hp	22	28
Impairment recorded on idle compressor units retired from the active fleet | $	$ 4,710	$ 8,245