Acquisitions and Divestitures - Summary of Unaudited Pro Forma Financial Information (Detail) - Legacy Amplify, Midstates and Midstates Holdings, Inc. [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Acquisition [Line Items]
Revenues	$ 80,482	$ 139,870	$ 258,547	$ 425,306
Net income (loss)	$ 6,845	$ 20,542	$ 6,236	$ 25,269
Earnings per share:
Basic	$ 0.20	$ 0.41	$ 0.24	$ 0.50
Diluted	$ 0.20	$ 0.41	$ 0.24	$ 0.50