Document and Entity Information - shares	6 Months Ended
	Dec. 31, 2016	Feb. 03, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	Dec. 31, 2016
Amendment Flag	false
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2017
Current Fiscal Year End Date	--06-30
Entity Central Index Key	0000061398
Entity Filer Category	Smaller Reporting Company
Entity Registrant Name	MAGELLAN PETROLEUM CORP /DE/
Entity Common Stock, Shares Outstanding		5,879,610