Document and Entity Information	9 Months Ended
	Sep. 30, 2012	Oct. 31, 2012
Entity Information [Line Items]
Entity Registrant Name	SWIFT ENERGY CO
Entity Central Index Key	0000351817
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Document Period End Date	Sep. 30, 2012
Amendment Flag	false
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		42,923,371