Document and Entity Information	12 Months Ended
	Oct. 15, 2012
Risk/Return:
Document Type	485BPOS
Document Period End Date	Jun. 30, 2012
Registrant Name	Midas Series Trust
Central Index Key	0000770200
Amendment Flag	false
Document Creation Date	Oct. 11, 2012
Document Effective Date	Oct. 15, 2012
Prospectus Date	Oct. 15, 2012