Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Nov. 11, 2016
Document and Entity Information
Entity Registrant Name	MADRIGAL PHARMACEUTICALS, INC.
Entity Central Index Key	0001157601
Document Type	10-Q/A
Document Period End Date	Sep. 30, 2016
Amendment Flag	true
Amendment Description	Unless the context indicates otherwise, references herein to "Madrigal," the "Company," "we," "our," and "us" mean Madrigal Pharmaceuticals, Inc. and its subsidiaries. We are filing this Amendment No. 2 to Form 10-Q/A (this "Second Amended Form 10-Q") to amend our Quarterly Report on Form 10-Q for the fiscal quarter ended September 30, 2016 (the "Original Form 10-Q"), as originally filed with the Securities and Exchange Commission (the "Commission") on November 14, 2016 and later amended by Amendment No. 1 to Form 10-Q/A (the "First Amended Form 10-Q"), as filed with the Commission on November 16, 2016, to reflect a restatement of our condensed consolidated financial statements. The purpose of this Second Amended Form 10-Q is to restate the calculation of weighted average shares outstanding, which is used in the computation of net loss per share and the retrospective application of the reverse merger recapitalization of stockholders' equity. This restatement has no impact on previously reported assets, liabilities, expenses, net loss or cash flows. As described in Note 4 of our consolidated financial statements, misstatements were identified in connection with our retrospective application of the reverse merger recapitalization on the December 31, 2015 stockholders' equity and the weighted average number of common shares outstanding used in the basic and diluted net loss per common share for all periods presented in 2016 and 2015. We determined that our unaudited condensed consolidated financial statements for the three and nine months ended September 30, 2015 and 2016, as reported in the Original Form 10-Q, should no longer be relied upon with regard to earnings per share, and that a restatement of these financial statements was required. As of September 30, 2016, our management concluded that we did not maintain effective internal control over financial reporting due to the existence of a material weakness that resulted in the errors identified. Due to the existence of this material weakness, management concluded that our disclosure controls and procedures were not effective as of September 30, 2016. See Item 4 of this Second Amended Form 10-Q.
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		11,570,149
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q3