Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Nov. 06, 2015
Document Information [Line Items]
Entity Registrant Name	HEARTLAND EXPRESS INC
Entity Central Index Key	0000799233
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		85,152,840