Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 07, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	HALLADOR ENERGY COMPANY
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		29,763,449
Amendment Flag	false
Entity Central Index Key	0000788965
Entity Filer Category	Accelerated Filer
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2
Trading Symbol	HNRG