Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Selected Quarterly Financial Data (Unaudited)
Total revenues	$ 50.1	$ 41.1	$ 33.7	$ 29.1	$ 26.3	$ 16.1	$ 5.6	$ 4.8	$ 154.0	$ 52.8	$ 21.2
Operating income (loss)	(5.2)	(4.8)	(4.9)	(5.7)	(2.8)	0.3	(0.6)	(1.3)	(20.6)	(4.5)	(6.4)
Net income (loss)	(5.6)	(9.5)	$ (6.0)	$ (6.2)	$ (3.0)	$ 0.2	$ (0.7)	$ (1.4)	(27.3)	$ (5.0)	$ (6.7)
Net loss attributable to Ranger Energy Services, Inc.	$ (3.1)	$ (3.5)							$ (6.6)
Basic net loss per share (in dollars per share)	$ (0.36)	$ (0.42)							$ (0.78)
Diluted net loss per share (in dollars per share)	$ (0.36)	$ (0.42)							$ (0.78)