Net Income per Share - Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net income attributable to Liberty Oilfield Services Inc. Stockholders	$ 1,720	$ 18,121
Denominator, Basic [Abstract]
Basic weighted average shares outstanding (in shares)	81,651	67,427
Basic net income per share attributable to Liberty Oilfield Services Inc. Stockholders (in dollars per share)	$ 0.02	$ 0.27
Numerator, Diluted [Abstract]
Net income attributable to Liberty Oilfield Services Inc. Stockholders	$ 1,720	$ 18,121
Effect of exchange of the shares of Class B Common Stock for shares of Class A Common Stock	632	11,831
Net Income (Loss) Available to Common Stockholders, Diluted	$ 2,352	$ 29,952
Denominator, Diluted [Abstract]
Basic weighted average shares outstanding (in shares)	81,651	67,427
Effect of dilutive securities:
Restricted stock (in shares)	268	601
Restricted stock units (in shares)	2,394	1,581
Class B Common Stock (in shares)	30,639	44,562
Diluted weighted average shares outstanding (in shares)	114,952	114,171
Diluted net income per share attributable to Liberty Oilfield Services Inc. Stockholders (in dollars per share)	$ 0.02	$ 0.26