Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Nov. 01, 2019
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		30,248,953
Entity Current Reporting Status	Yes
Amendment Flag	false
Entity Central Index Key	0000788965
Entity Filer Category	Accelerated Filer
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Small Business	true