Long-Term Incentive Plans - Summary of Non-vested Stock Option Activity (Detail) - Stock Options [Member] - Midstates 2016 Long Term Incentive Plan [Member]	2 Months Ended
	Sep. 30, 2019 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding, Number of units, Beginning balance | shares	54,365
Granted, Number of units | shares	0
Forfeited, Number of units | shares	0
Vested, Number of units | shares	(50,870)
Outstanding, Number of units, Ending balance | shares	3,495
Outstanding, Weighted average grant date fair value per unit, Beginning balance | $ / shares	$ 19.68
Granted, Weighted average grant date fair value per unit | $ / shares	0
Forfeited, Weighted average grant date fair value per unit | $ / shares	0
Vested, Weighted average grant date fair value per unit | $ / shares	19.68
Outstanding, Weighted average grant date fair value per unit, Ending balance | $ / shares	$ 19.66