Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 24, 2016	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Document Information [Line Items]
Entity Registrant Name	HEARTLAND EXPRESS INC
Entity Central Index Key	0000799233
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Amendment Flag	false
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		83,198,245
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	102,400	94,449		183,100	211,500	276,800
Entity Public Float			$ 1,011,122,650