Document and Entity Information (USD $)	12 Months Ended
Dec. 31, 2013	Jan. 31, 2014	Jun. 30, 2013
Document and Entity Information [Abstract]
Entity Registrant Name	SWIFT ENERGY CO
Entity Central Index Key	0000351817
Document Type	10-K/A
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2013
Amendment Flag	true
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	FY
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		43,475,471
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 504,125,149
Amendment Description	Explanatory NoteWe are filing this amended Form 10-K/A (“Form 10-K/A”) to amend our Annual Report on Form 10-K for the year ended December 31, 2013, originally filed with the Securities and Exchange Commission (the “SEC”) on March 3, 2014 (“Original Filing”), to restate our consolidated financial statements and related footnote disclosures for the years ended December 31, 2013, 2012 and 2011. This Form 10-K/A also includes certain restated quarterly information under the Supplementary Information heading in Item 8 of this Form 10-K/A. This Form 10-K/A also amends certain other Items in the Original Filing, as listed in “Items Amended in this Form 10-K/A” below. Restatement BackgroundOn November 10, 2014, the Audit Committee of our Board of Directors (the “Audit Committee”), after discussion with management and Ernst & Young LLP (“EY”), our independent registered public accounting firm, determined that the following financial statements previously filed with the SEC should no longer be relied upon: (1) the audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2013, 2012 and 2011; (2) the unaudited condensed consolidated financial statements included in our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2013 and 2012, June 30, 2013 and 2012, and September 30, 2013 and 2012; and (3) the unaudited condensed consolidated financial statements included in our quarterly reports on Form 10-Q for the quarters ended March 31, 2014 and June 30, 2014. Similarly, the related press releases, auditor reports on the consolidated financial statements as of and for the year ended December 31, 2013 and the effectiveness of internal control over financial reporting as of December 31, 2013, management’s report on the effectiveness of internal control over financial reporting as of December 31, 2013, and stockholder communications describing the portion of our financial statements for these periods that need to be restated should no longer be relied upon.In connection with the preparation of our financial statements for the quarter ended September 30, 2014, we determined that an error occurred in our model used for the ceiling test calculation prepared at December 31, 2013, March 31, 2009 and December 31, 2008, to determine whether the net book value of the Company's oil and gas properties exceed the ceiling. Specifically, this error related to incorrectly including the deferred income tax effect of the Company's asset retirement obligations when computing the ceiling test limitation of its oil and natural gas properties under the full-cost method of accounting. The Company determined that the error caused a material overstatement of its full-cost ceiling test write-down of oil and gas properties in periods prior to 2014, including associated depletion for all periods presented. As a result of this error, we have restated our audited consolidated financial statements for the years ended December 31, 2013, 2012 and 2011 and our unaudited condensed consolidated financial information for the quarters ended March 31, 2013, June 30, 2013, September 30, 2013, and December 31, 2013.As of December 31, 2013, the correction of this error principally increased the Company's net oil and gas property balances by approximately $49 million, increased the net deferred tax liabilities by approximately $18 million, and increased retained earnings by approximately $31 million. Approximately $15 million of the increase in retained earnings is related to periods prior to 2013, more specifically to the first quarter of 2009 and the fourth quarter of 2008. For the year ended December 31, 2013, the correction of the ceiling test error also resulted in a decrease in our ceiling-test write-down for the year ended December 31, 2013 of approximately $27 million, which was partially offset by an increase in our depreciation, depletion and amortization expense for the year of approximately $1 million. Further, these corrections increased net income for the year ended December 31, 2013 by approximately $16 million (net of an increase to the income tax benefit of approximately $9 million for the period). Please refer to Note 1A - “Restatement of Previously Issued Consolidated Financial Statements” of this Form 10-K/A for more information regarding the impact of these adjustments. Along with restating our financial statements to correct the error discussed above, we are making adjustments for certain previously identified immaterial accounting errors related to the periods covered by this Form 10-K/A. When these financial statements were originally issued, we assessed the impact of these errors and concluded that they were not material to our financial statements for each of the years ended December 31, 2013, 2012, and 2011, and reported fiscal quarters within each of these years. However, in conjunction with our need to restate our financial statements as a result of the error noted above, we have determined that it would be appropriate within this Form 10-K/A to record all such previously unrecorded adjustments. Please refer to Note 1A - “Restatement of Previously Issued Consolidated Financial Statements” of this Form 10-K/A for more information regarding the impact of these adjustments. Because these revisions are treated as corrections of errors to our prior period financial results, the revisions are considered to be a “restatement” under U.S. generally accepted accounting principles. Accordingly, the revised financial information included in this Annual Report on Form 10-K/A has been identified as “restated”. Restatement of Other Financial StatementsIn addition to this Form 10-K/A, we are concurrently filing an amendment to our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2014 and June 30, 2014 (the “Form 10-Q/As”). We are filing the Form 10-Q/As to restate our unaudited condensed consolidated financial statements and related financial information for the periods contained in those reports and to amend certain other Items within those reports.Internal Control ConsiderationOur management has determined that there was a deficiency in our internal control over financial reporting that constitutes a material weakness, as defined by SEC regulations, at December 31, 2013, as discussed in Part II, Item 9A of this Form 10-K/A.Items Amended in this Form 10-K/AFor the convenience of the reader, this Form 10-K/A sets forth the Original Filing, in its entirety, as modified and superseded as necessary to reflect the restatement. The following items in the Original Filing have been amended as a result of, and to reflect, the restatement:A.Part II, Item 6. Selected Financial DataB.Part II, Item 7. Management’s Discussion and Analysis of Financial Condition and Results of OperationsC.Part II, Item 8. Financial Statements and Supplementary DataD.Part II, Item 9A. Controls and ProceduresE.Part IV, Item 15. Exhibits, Financial Statement SchedulesThis report on Form 10-K/A is presented as of the filing date of the Original Form 10-K and does not reflect events occurring after that date, or modify or update the information contained therein in any way other than as required to correct the error and record the adjustments described above.In accordance with applicable SEC rules, this Form 10-K/A includes new certifications required by Sections 302 and 906 of the Sarbanes-Oxley Act of 2002, as amended, from our Chief Executive Officer and Chief Financial Officer dated as of the filing date of this Form 10-K/A.

Document and Entity Information (USD $)

12 Months Ended

Dec. 31, 2013

Jan. 31, 2014

Jun. 30, 2013

Document and Entity Information [Abstract]

Entity Registrant Name

SWIFT ENERGY CO

Entity Central Index Key

0000351817

Document Type

10-K/A

Current Fiscal Year End Date

--12-31

Document Period End Date

Dec. 31, 2013

Amendment Flag

true

Document Fiscal Year Focus

2013

Document Fiscal Period Focus

Entity Filer Category

Large Accelerated Filer

Entity Common Stock, Shares Outstanding

43,475,471

Entity Well-known Seasoned Issuer

Entity Voluntary Filers

Entity Current Reporting Status

Yes

Entity Public Float

$ 504,125,149

Amendment Description

Explanatory NoteWe are filing this amended Form 10-K/A (“Form 10-K/A”) to amend our Annual Report on Form 10-K for the year ended December 31, 2013, originally filed with the Securities and Exchange Commission (the “SEC”) on March 3, 2014 (“Original Filing”), to restate our consolidated financial statements and related footnote disclosures for the years ended December 31, 2013, 2012 and 2011. This Form 10-K/A also includes certain restated quarterly information under the Supplementary Information heading in Item 8 of this Form 10-K/A. This Form 10-K/A also amends certain other Items in the Original Filing, as listed in “Items Amended in this Form 10-K/A” below. Restatement BackgroundOn November 10, 2014, the Audit Committee of our Board of Directors (the “Audit Committee”), after discussion with management and Ernst & Young LLP (“EY”), our independent registered public accounting firm, determined that the following financial statements previously filed with the SEC should no longer be relied upon: (1) the audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2013, 2012 and 2011; (2) the unaudited condensed consolidated financial statements included in our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2013 and 2012, June 30, 2013 and 2012, and September 30, 2013 and 2012; and (3) the unaudited condensed consolidated financial statements included in our quarterly reports on Form 10-Q for the quarters ended March 31, 2014 and June 30, 2014. Similarly, the related press releases, auditor reports on the consolidated financial statements as of and for the year ended December 31, 2013 and the effectiveness of internal control over financial reporting as of December 31, 2013, management’s report on the effectiveness of internal control over financial reporting as of December 31, 2013, and stockholder communications describing the portion of our financial statements for these periods that need to be restated should no longer be relied upon.In connection with the preparation of our financial statements for the quarter ended September 30, 2014, we determined that an error occurred in our model used for the ceiling test calculation prepared at December 31, 2013, March 31, 2009 and December 31, 2008, to determine whether the net book value of the Company's oil and gas properties exceed the ceiling. Specifically, this error related to incorrectly including the deferred income tax effect of the Company's asset retirement obligations when computing the ceiling test limitation of its oil and natural gas properties under the full-cost method of accounting. The Company determined that the error caused a material overstatement of its full-cost ceiling test write-down of oil and gas properties in periods prior to 2014, including associated depletion for all periods presented. As a result of this error, we have restated our audited consolidated financial statements for the years ended December 31, 2013, 2012 and 2011 and our unaudited condensed consolidated financial information for the quarters ended March 31, 2013, June 30, 2013, September 30, 2013, and December 31, 2013.As of December 31, 2013, the correction of this error principally increased the Company's net oil and gas property balances by approximately $49 million, increased the net deferred tax liabilities by approximately $18 million, and increased retained earnings by approximately $31 million. Approximately $15 million of the increase in retained earnings is related to periods prior to 2013, more specifically to the first quarter of 2009 and the fourth quarter of 2008. For the year ended December 31, 2013, the correction of the ceiling test error also resulted in a decrease in our ceiling-test write-down for the year ended December 31, 2013 of approximately $27 million, which was partially offset by an increase in our depreciation, depletion and amortization expense for the year of approximately $1 million. Further, these corrections increased net income for the year ended December 31, 2013 by approximately $16 million (net of an increase to the income tax benefit of approximately $9 million for the period). Please refer to Note 1A - “Restatement of Previously Issued Consolidated Financial Statements” of this Form 10-K/A for more information regarding the impact of these adjustments. Along with restating our financial statements to correct the error discussed above, we are making adjustments for certain previously identified immaterial accounting errors related to the periods covered by this Form 10-K/A. When these financial statements were originally issued, we assessed the impact of these errors and concluded that they were not material to our financial statements for each of the years ended December 31, 2013, 2012, and 2011, and reported fiscal quarters within each of these years. However, in conjunction with our need to restate our financial statements as a result of the error noted above, we have determined that it would be appropriate within this Form 10-K/A to record all such previously unrecorded adjustments. Please refer to Note 1A - “Restatement of Previously Issued Consolidated Financial Statements” of this Form 10-K/A for more information regarding the impact of these adjustments. Because these revisions are treated as corrections of errors to our prior period financial results, the revisions are considered to be a “restatement” under U.S. generally accepted accounting principles. Accordingly, the revised financial information included in this Annual Report on Form 10-K/A has been identified as “restated”. Restatement of Other Financial StatementsIn addition to this Form 10-K/A, we are concurrently filing an amendment to our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2014 and June 30, 2014 (the “Form 10-Q/As”). We are filing the Form 10-Q/As to restate our unaudited condensed consolidated financial statements and related financial information for the periods contained in those reports and to amend certain other Items within those reports.Internal Control ConsiderationOur management has determined that there was a deficiency in our internal control over financial reporting that constitutes a material weakness, as defined by SEC regulations, at December 31, 2013, as discussed in Part II, Item 9A of this Form 10-K/A.Items Amended in this Form 10-K/AFor the convenience of the reader, this Form 10-K/A sets forth the Original Filing, in its entirety, as modified and superseded as necessary to reflect the restatement. The following items in the Original Filing have been amended as a result of, and to reflect, the restatement:A.Part II, Item 6. Selected Financial DataB.Part II, Item 7. Management’s Discussion and Analysis of Financial Condition and Results of OperationsC.Part II, Item 8. Financial Statements and Supplementary DataD.Part II, Item 9A. Controls and ProceduresE.Part IV, Item 15. Exhibits, Financial Statement SchedulesThis report on Form 10-K/A is presented as of the filing date of the Original Form 10-K and does not reflect events occurring after that date, or modify or update the information contained therein in any way other than as required to correct the error and record the adjustments described above.In accordance with applicable SEC rules, this Form 10-K/A includes new certifications required by Sections 302 and 906 of the Sarbanes-Oxley Act of 2002, as amended, from our Chief Executive Officer and Chief Financial Officer dated as of the filing date of this Form 10-K/A.