Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	May 03, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	Gener8 Maritime, Inc.
Entity Central Index Key	0001443799
Document Type	10-K/A
Document Period End Date	Dec. 31, 2017
Amendment Flag	true
Amendment Description	This Amendment No. 2 on Form 10-K/A (the "Amendment") amends our Annual Report on Form 10-K for the fiscal year ended December 31, 2017, that was filed with the Securities and Exchange Commission ("SEC") on March 15, 2018 (the "Original Filing"), as amended by Amendment No. 1 that was filed with the SEC on April 30, 2018 (the "Amended Filing" and, together with the Original Filing, the "Annual Report"). We are filing this Amendment to amend and restate our audited consolidated financial statements and related disclosures for the year ended December 31, 2017 (the "Restatement"), and to re-file Exhibit 12.01 in order to correct numerical errors in the computation of the ratio of earnings to fixed charges for the year ended December 31, 2017 that appeared in Exhibit 12.01 to the Original Filing. Accordingly, Exhibit 12.01 filed with this Amendment supersedes and replaces Exhibit 12.01 to the Original Filing. Except as described below with respect to Parts I and II, and except as it relates to Exhibit 12.01, no other changes are made to the Annual Report. The Annual Report continues to speak as of the date of the Original Filing. Unless expressly stated, this Amendment does not reflect events occurring after the filing of the Original Filing, nor does it modify or update in any way the disclosures contained in the Original Filing. In the context of this Amendment, unless otherwise indicated or the context otherwise requires, "Gener8," the "Company," "we," "us," and "our" refer to Gener8 Maritime, Inc. and its subsidiaries.
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 245.7
Entity Common Stock, Shares Outstanding		83,267,426
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY