Acquisitions and Divestitures - Summary of Unaudited Pro Forma Financial Information (Detail) - Legacy Amplify, Midstates and Midstates Holdings, Inc. [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Revenues	$ 336,326	$ 545,226
Net income (loss)	$ (22,926)	$ 146,845
Earnings per share:
Basic	$ (0.78)	$ 3.18
Diluted	$ (0.78)	$ 3.18