Earnings (Loss) Per Share - Schedule of Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net income (loss) (numerator):
Net income (loss) attributable to common stockholders of Rosehill Resources Inc. - basic	$ (23,349)	$ 26,661	$ (8,520)
Add: Dividends on Series A Preferred Stock	0	7,938	0
Add: Net income (loss) attributable to the noncontrolling interest, net of taxes	0	47,432	0
Net income (loss) attributable to common stockholders of Rosehill Resources Inc. - diluted	$ (23,349)	$ 82,031	$ (8,520)
Weighted average shares (denominator):
Weighted average shares - basic (shares)	14,475	8,196	5,945
Add: Dilutive effects of Series A Preferred Stock (shares)	0	8,495	0
Add: Dilutive effects of Class B Common Stock (shares)	0	29,808	0
Weighted average shares – diluted (shares)	14,475	46,499	5,945
Basic earnings (loss) per share (USD per share)	$ (1.61)	$ 3.25	$ (1.43)
Diluted earnings (loss) per share (USD per share)	$ (1.61)	$ 1.76	$ (1.43)