W&T Offshore (WTI) 10-Q 8 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Nov. 05, 2013
Document Information [Line Items]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'WTI	'
Entity Registrant Name	'W&T OFFSHORE INC	'
Entity Central Index Key	'0001288403	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	75,277,080

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$15,227	$12,245
Receivables:	'	'
Oil and natural gas sales	85,221	97,733
Joint interest and other	31,492	56,439
Income taxes	'	47,884
Total receivables	116,713	202,056
Restricted cash and cash equivalents	16,459	'
Prepaid expenses and other assets	32,850	25,822
Total current assets	181,249	240,123
Property and equipment – at cost:	'	'
Oil and natural gas properties and equipment (full cost method, of which $129,584 at September 30, 2013 and $123,503 at December 31, 2012 were excluded from amortization)	7,120,086	6,694,510
Furniture, fixtures and other	21,325	21,786
Total property and equipment	7,141,411	6,716,296
Less accumulated depreciation, depletion and amortization	4,950,768	4,655,841
Net property and equipment	2,190,643	2,060,455
Restricted deposits for asset retirement obligations	34,966	28,466
Other assets	16,842	19,943
Total assets	2,423,700	2,348,987
Current liabilities:	'	'
Accounts payable	129,988	123,885
Undistributed oil and natural gas proceeds	41,278	37,073
Asset retirement obligations	95,014	92,630
Accrued liabilities	51,048	21,021
Total current liabilities	317,328	274,609
Long-term debt	1,052,984	1,087,611
Asset retirement obligations, less current portion	267,093	291,423
Deferred income taxes	177,404	145,249
Other liabilities	15,859	8,908
Commitments and contingencies	'	'
Shareholders’ equity:	'	'
Preferred stock, $0.00001 par value; 20,000,000 shares authorized; 0 issued at September 30, 2013 and December 31, 2012	'	'
Common stock, $0.00001 par value; 118,330,000 shares authorized; 78,146,253 issued and 75,277,080 outstanding at September 30, 2013, and 78,118,803 issued and 75,249,630 outstanding at December 31, 2012	1	1
Additional paid-in capital	404,604	396,186
Retained earnings	212,594	169,167
Treasury stock, at cost	-24,167	-24,167
Total shareholders’ equity	593,032	541,187
Total liabilities and shareholders’ equity	$2,423,700	$2,348,987

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Oil and natural gas properties and equipment - full cost method, amount excluded from amortization	$129,584	$123,503
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, issued	0	0
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	118,330,000	118,330,000
Common stock, issued	78,146,253	78,118,803
Common stock, outstanding	75,277,080	75,249,630

Condensed_Consolidated_Stateme

Condensed Consolidated Statements Of Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues	$244,555	$185,946	$739,160	$637,345
Operating costs and expenses:	'	'	'	'
Lease operating expenses	67,346	53,411	194,935	170,349
Production taxes	1,807	1,353	5,375	4,174
Gathering and transportation	3,611	2,810	12,663	11,140
Depreciation, depletion, amortization and accretion	104,143	77,462	312,911	251,894
General and administrative expenses	20,024	18,691	60,979	62,793
Derivative loss	15,659	24,659	6,186	14,421
Total costs and expenses	212,590	178,386	593,049	514,771
Operating income	31,965	7,560	146,111	122,574
Interest expense:	'	'	'	'
Incurred	21,373	14,791	64,157	43,409
Capitalized	-2,573	-3,383	-7,537	-9,899
Other income	9,062	202	9,075	210
Income (loss) before income tax expense	22,227	-3,646	98,566	89,274
Income tax expense (benefit)	8,033	-2,175	35,358	33,959
Net income (loss)	$14,194	($1,471)	$63,208	$55,315
Basic and diluted earnings (loss) per common share	$0.19	($0.02)	$0.83	$0.73
Dividends declared per common share	$0.09	$0.08	$0.26	$0.24

Condensed_Consolidated_Stateme1

Condensed Consolidated Statement Of Changes In Shareholders' Equity (USD $)	Total	Common Stock Outstanding	Additional Paid-In Capital	Retained Earnings	Treasury Stock
In Thousands, except Share data
Beginning Balances at Dec. 31, 2012	$541,187	$1	$396,186	$169,167	($24,167)
Beginning Balances (in shares) at Dec. 31, 2012	75,249,630	75,250,000	'	'	2,869,000
Cash dividends	-19,570	'	'	-19,570	'
Share-based compensation	8,457	'	8,457	'	'
Other	-250	'	-39	-211	'
Net income	63,208	'	'	63,208	'
Other, Shares	'	27,000	'	'	'
Ending Balances at Sep. 30, 2013	$593,032	$1	$404,604	$212,594	($24,167)
Ending Balances (in shares) at Sep. 30, 2013	75,277,080	75,277,000	'	'	2,869,000

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements Of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating activities:	'	'
Net income	$63,208	$55,315
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation, depletion, amortization and accretion	312,911	251,894
Amortization of debt issuance costs and premium	1,366	2,046
Share-based compensation	8,457	9,137
Derivative loss	6,186	14,421
Cash payments on derivative settlements	-6,855	-6,960
Deferred income taxes	31,581	44,465
Changes in operating assets and liabilities:	'	'
Oil and natural gas receivables	12,511	30,320
Joint interest and other receivables	24,947	3,935
Insurance receivables	5,117	500
Income taxes	53,433	-24,327
Prepaid expenses and other assets	-10,815	670
Asset retirement obligation settlements	-59,188	-63,150
Accounts payable, accrued liabilities and other	32,974	33,223
Net cash provided by operating activities	475,833	351,489
Investing activities:	'	'
Investment in oil and natural gas properties and equipment	-423,092	-312,372
Proceeds from sales of assets and other, net	21,011	30,453
Change in restricted cash	-16,459	-24,026
Deposit for acquisition	'	-22,800
Purchases of furniture, fixtures and other	-1,327	-2,125
Net cash used in investing activities	-419,867	-330,870
Financing activities:	'	'
Borrowings of long-term debt – revolving bank credit facility	335,000	316,000
Repayments of long-term debt – revolving bank credit facility	-368,000	-314,000
Debt issuance costs	-164	-2,081
Dividends to shareholders	-19,570	-17,848
Other	-250	-209
Net cash used in financing activities	-52,984	-18,138
Increase in cash and cash equivalents	2,982	2,481
Cash and cash equivalents, beginning of period	12,245	4,512
Cash and cash equivalents, end of period	$15,227	$6,993

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2013
Basis of Presentation	'
	1.  Basis of Presentation
	Operations.  W&T Offshore, Inc. and subsidiaries, referred to herein as “W&T” or the “Company,” is an independent oil and natural gas producer focused primarily in the Gulf of Mexico and onshore Texas.  The Company is active in the exploration, development and acquisition of oil and natural gas properties.
	Interim Financial Statements.  The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim periods and the appropriate rules and regulations of the Securities and Exchange Commission (“SEC”).  Accordingly, the condensed consolidated financial statements do not include all of the information and footnote disclosures required by GAAP for complete financial statements for annual periods.  In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included.
	Operating results for interim periods are not necessarily indicative of the results that may be expected for the entire year.  These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
	Reclassifications.  Certain reclassifications have been made to the prior periods’ financial statements to conform to the current presentation.  Deferred income taxes – current asset was combined with Prepaid expenses and other assets on the Balance Sheet, Income taxes payable was combined with Accrued liabilities on the Balance Sheet, and changes in Other liabilities was combined with the changes in Accounts payable and accrued liabilities on the Statement of Cash Flows.
	Use of Estimates.  The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods.  Actual results could differ from those estimates.
	Recent Accounting Developments.  In December 2011, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2011-11, Balance Sheet (Topic 210): Disclosures about Offsetting Assets and Liabilities which applies to certain items in the statement of financial position (balance sheet), and was further clarified in January 2013 by ASU 2013-01, Balance Sheet (Topic 210): Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities, which clarified the scope of ASU 2011-11 to derivative instruments, repurchase agreements and securities lending transactions.  The effective date for the amendments is for annual periods beginning after January 1, 2013, and interim periods within those annual periods.  ASU 2011-11 requires disclosures of the gross and net amounts for items eligible for offset in the balance sheet.  The Company’s derivative financial instruments are subject to master netting agreements and the Company records its derivative financial instruments on a gross basis by contract; therefore, the revisions relate to disclosure of the Company’s derivative financial instruments on a net basis.  Other items of the ASUs were not applicable to the Company.
	In February 2013, the FASB issued ASU 2013-04, Liabilities (Topic 405): Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation is Fixed at the Reporting Date, which requires an entity that is joint and severally liable to measure the obligation as the sum of the amount the entity has agreed with co-obligors to pay and any additional amount it expects to pay on behalf of one or more co-obligors.  Required disclosures include a description of the nature of the arrangement, how the liability arose, the relationship with co-obligors and the terms and conditions of the arrangement.  The effective date for the amendment is for annual periods beginning after December 15, 2013, and interim periods within those annual periods.  The amendment is to be applied retrospectively to all prior periods presented.  The Company is currently assessing the impact of ASU 2013-04 to determine the effects on the balance sheet and disclosures, if any.
	In July 2013, the FASB issued ASU 2013-11, Income Taxes (Topic 740); Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a similar Tax Loss, or a Tax Credit Carryforward Exists a consensus of the FASB Emerging Task Force, which provided guidance on the presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists.  This guidance requires an entity to present an unrecognized tax benefit as a liability in the financial statements if (i) a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date under the tax law of the applicable jurisdiction to settle any additional income taxes that would result from the disallowance of a tax position, or (ii) the tax law of the applicable jurisdiction does not require the entity to use, and the entity does not intend to use, the deferred tax asset to settle any additional income taxes that would result from the disallowance of a tax position. Otherwise, an unrecognized tax benefit is required to be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward.  Previously, there was diversity in practice as no explicit guidance existed. The amendment is effective for annual periods and interim periods beginning after December 15, 2013.  Early adoption is permitted and the amendment is to be applied prospectively.  The Company is currently assessing the impact of ASU 2013-11 to determine the effects on the balance sheet and disclosures, if any.
	Other income.  For the three and nine months ended September 30, 2013, the amounts reported consisted primarily of $9.2 million received in conjunction with a payment to W&T for an option exercised by a counterparty.  Partially offsetting the proceeds were related third-party expenses of $0.1 million.

Acquisitions_and_Divestitures

Acquisitions and Divestitures	9 Months Ended
	Sep. 30, 2013
Acquisitions and Divestitures	'
	2.  Acquisitions and Divestitures
	2013 Divestitures.  On July 11, 2013, we sold our non-operated working interest in two offshore fields located in the Gulf of Mexico; the Green Canyon 60 field and the Green Canyon 19 field.  The effective date was October 1, 2011 and we retained the deep rights in both fields.  Due to the length of time from the effective date, we paid $4.3 million to sell the properties as revenues exceeded operating expenses and the purchase price for the period between the effective date and the close date.  In connection with the sale, we reversed $15.6 million of our asset retirement obligations (“ARO”).
	On September 26, 2013, we sold our working interests in the West Delta area block 29 with an effective date of January 1, 2013.  The property is located in the Gulf of Mexico.  Including adjustments for the effective date, the net proceeds were $16.5 million.   The transaction was structured as a like-kind exchange under the Internal Revenue Service Code (“IRC”) Section 1031 and other applicable regulations, with funds held by a qualified intermediary until replacement purchases are made.  Replacement purchases are expected to be consummated within the replacement periods defined under the IRC.  The net proceeds are recorded on the Balance Sheet in Restricted cash and cash equivalents due to the restrictions on the use of the cash under IRC regulations for like-kind exchanges.  In connection with this sale, we reversed $3.9 million of ARO.
	2012 Acquisition.  On October 5, 2012, we acquired from Newfield Exploration Company and its subsidiary, Newfield Exploration Gulf Coast LLC (together, “Newfield”) certain oil and gas leasehold interests in the Gulf of Mexico (the “Newfield Properties”).  The Newfield Properties consist of leases covering 78 offshore blocks on approximately 416,000 gross acres (268,000 net acres) (excluding overriding royalty interests).  Including adjustments from an effective date of July 1, 2012, the adjusted purchase price was $205.7 million and we assumed the future ARO associated with the Newfield Properties.  The acquisition was funded from borrowings under our revolving bank credit facility and cash on hand.  Subsequently in the same month, the amounts borrowed under our revolving bank credit facility were paid down with funds provided from the issuance of long-term debt in October 2012.  See Note 6 for information on long-term debt.  The purchase price was finalized during the second quarter of 2013 and no further adjustments are expected.  Adjustments to the purchase price of a net increase of $0.2 million were recorded in the nine months ended September 30, 2013.
	The following table presents the purchase price allocation, including adjustments, for the acquisition of the Newfield Properties (in thousands):
	Oil and natural gas properties and equipment	$		237,396
	Asset retirement obligations – current			(7,250	)
	Asset retirement obligations – non-current			(24,414	)
	Total cash paid	$		205,732
	The acquisition was recorded at fair value, which was determined by applying the market and income approaches using Level 3 inputs.  The Level 3 inputs were: (i) analysis of comparable transactions obtained from various third-parties, (ii) estimates of ultimate recoveries of reserves and (iii) estimates of discounted cash flows based on estimated reserve quantities, reserve categories, timing of production, costs to produce and develop reserves, future prices, ARO and discount rates.  The estimates and assumptions were determined by management and third-parties.  The fair value is based on subjective estimates and assumptions, which are inherently imprecise, and the actual realized values could vary significantly from these estimates.  No goodwill was recorded for the Newfield Properties acquisition.
	Revenues, Net Income and Pro Forma Financial Information — Unaudited
	The Newfield Properties were not included in our consolidated results until the closing date of October 5, 2012.  For the three months ended September 30, 2013, the Newfield Properties accounted for $31.9 million of revenues, $5.5 million of direct operating expenses, $14.7 million of depreciation, depletion, amortization and accretion (“DD&A”) and $4.1 million of income taxes, resulting in $7.6 million of net income.  For the nine months ended September 30, 2013, the Newfield Properties accounted for $94.2 million of revenues, $19.6 million of direct operating expenses, $41.1 million of DD&A and $11.7 million of income taxes, resulting in $21.8 million of net income.  The net income attributable to these properties does not reflect certain expenses, such as general and administrative (“G&A”) expense and interest expense; therefore, this information is not intended to report results as if these operations were managed on a stand-alone basis.  In addition, the Newfield Properties are not recorded in a separate entity for tax purposes; therefore, income tax was estimated using the federal statutory tax rate.  Expenses associated with acquisition activities and transition activities related to the acquisition of the Newfield Properties were less than $0.1 million for the three and nine months ended September 30, 2012.
	Consistent with the computation of pro forma financial information presented in Item 8, Financial Statements and Supplementary Data, in the Annual Report on Form 10-K for the year end December 31, 2012, the unaudited pro forma financial information was computed as if the acquisition of the Newfield Properties had been completed on January 1, 2011.  The financial information was derived from W&T’s audited historical consolidated financial statements for annual periods, W&T’s unaudited historical condensed consolidated financial statements for the interim periods, the Newfield Properties’ audited historical financial statement for 2011 and the Newfield Properties’ unaudited historical financial statements for the 2012 interim periods.
	The pro forma adjustments were based on estimates by management and information believed to be directly related to the purchase of the Newfield Properties.  The pro forma financial information is not necessarily indicative of the results of operations had the purchase occurred on January 1, 2011.  If the transaction had been in effect for the periods indicated, the results may have been substantially different.  For example, we may have operated the assets differently than Newfield; the realized sales prices for oil, natural gas liquids (“NGLs”) and natural gas may have been different; and the costs of operating the Newfield Properties may have been different.
	The following table presents a summary of our pro forma financial information (in thousands except earnings per share):
		Three Months Ended				Nine Months Ended
		30-Sep-12				30-Sep-12
	Revenues	$		217,714		$	741,808
	Net income			508			59,897
	Basic and diluted earnings per common share			0.01			0.79
	For the pro forma financial information, certain information was derived from financial records and certain information was estimated.
	The following table presents incremental items included in the pro forma information reported above for the Newfield Properties (in thousands):
		Three Months Ended				Nine Months Ended
		30-Sep-12				30-Sep-12
	Revenues (a)	$		31,768		$	104,463
	Direct operating expenses (a)			9,026			33,089
	Insurance and acquisition costs, net (b)			128			444
	DD&A (c)			15,757			52,634
	Interest expense (d)			3,960			11,881
	Capitalized interest (e)			148			634
	Income tax expense (f)			1,066			2,467
		The sources of information and significant assumptions are described below:
		(a)	Revenues and direct operating expenses for the Newfield Properties were derived from the historical financial records of Newfield.
		(b)	Incremental costs for insurance were estimated using the incremental costs to add the Newfield Properties to W&T’s insurance programs.  The direct operating expenses for the Newfield Properties described above exclude insurance costs.  Expenses were reduced for acquisition costs incurred.
		(c)	DD&A was estimated using the full-cost method and determined as the incremental DD&A expense due to adding the Newfield Properties’ costs, reserves and production into our currently existing full cost pool in order to compute such amounts.  The purchase price allocation included $13.1 million that was allocated to the pool of unevaluated properties for oil and natural gas interests.  Accordingly, no DD&A expense was estimated for the unevaluated properties.  ARO was estimated by W&T management.
		(d)	The acquisition was assumed to be funded entirely with borrowed funds.  Interest expense was computed using assumed borrowings of $205.7 million, which equates to the cash paid including purchase price adjustments and an interest rate of 7.7%, which equates to the effective yield on net proceeds for the additional senior notes issued shortly after the acquisition closed.
		(e)	Incremental capitalized interest was computed for the addition to the pool of unevaluated properties and the capitalization interest rate was adjusted for the assumed borrowings.
		(f)	Income tax expense was computed using the 35% federal statutory rate.
	2012 Divestiture.  On May 15, 2012, we sold our 40%, non-operated working interest in the South Timbalier 41 field located in the Gulf of Mexico for $30.5 million with an effective date of April 1, 2012.  The transaction was structured as a like-kind exchange under the IRC Section 1031 and other applicable regulations, with funds held by a qualified intermediary until replacement purchases could be executed.  Replacement purchases were consummated during 2012.  In connection with this sale, we reversed $4.0 million of ARO.

Hurricane_Remediation_and_Insu

Hurricane Remediation and Insurance Claims	9 Months Ended
	Sep. 30, 2013
Hurricane Remediation and Insurance Claims	'
	3.  Hurricane Remediation and Insurance Claims
	During the third quarter of 2008, Hurricane Ike caused substantial damage to certain of our properties and we continue to incur costs and submit claims to our insurance underwriters related to repairing such damage.  Our insurance policies in effect on the occurrence date of Hurricane Ike had a retention requirement of $10.0 million per occurrence, which has been satisfied, and coverage policy limits of $150.0 million for property damage due to named windstorms (excluding damage at certain facilities) and $250.0 million for, among other things, removal of wreckage if mandated by any governmental authority.
	We recognize insurance receivables with respect to capital, repair and plugging and abandonment costs as a result of hurricane damage when we deem those to be probable of collection, which arises when our insurance underwriters’ adjuster reviews and approves such costs for payment by the underwriters.  Claims that have been processed in this manner have customarily been paid on a timely basis.
	From the third quarter of 2008 through September 30, 2013, we have received $147.3 million from our insurance underwriters related to Hurricane Ike.  See Note 4 for additional information about the impact of hurricane related items on our ARO.   See Note 12 for information regarding legal actions taken by certain insurers and the Company.

Asset_Retirement_Obligations

Asset Retirement Obligations	9 Months Ended
	Sep. 30, 2013
Asset Retirement Obligations	'
	4.  Asset Retirement Obligations
	Our ARO primarily represents the estimated present value of the amount we will incur to plug, abandon and remediate our producing properties at the end of their productive lives in accordance with applicable laws.
	A summary of the changes to our ARO is as follows (in thousands):
	Balance, December 31, 2012	$	384,053
	Liabilities settled		(59,188	)
	Accretion of discount		16,236
	Disposition of properties		(19,564	)
	Liabilities incurred		372
	Revisions of estimated liabilities due to Hurricane Ike (1)		5,526
	Revisions of estimated liabilities – all other (1)		34,672
	Balance, September 30, 2013		362,107
	Less current portion		95,014
	Long-term	$	267,093
		(1) Revisions are primarily due to increases in the scope of work at several offshore locations required by the Bureau of Safety and Environmental Enforcement (“BSEE”).

Derivative_Financial_Instrumen

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2013
Derivative Financial Instruments	'
	5.  Derivative Financial Instruments
	Our market risk exposure relates primarily to commodity prices and interest rates. From time to time, we use various derivative instruments to manage our exposure to commodity price risk from sales of our oil and natural gas and interest rate risk from floating interest rates on our revolving bank credit facility. All of the derivative counterparties are also lenders or affiliates of lenders participating in our revolving bank credit facility.  We are exposed to credit loss in the event of nonperformance by the derivative counterparties; however, we currently anticipate that each of our derivative counterparties will be able to fulfill their contractual obligations. Additional collateral is not required by us due to the derivative counterparties’ collateral rights as lenders and we do not require collateral from our derivative counterparties.
	In accordance with GAAP, we record each derivative contract on the balance sheet as an asset or a liability at its fair value.  For additional information about fair value measurements, refer to Note 7.  We have elected not to designate our commodity derivative contracts as hedging instruments; therefore, all changes in the fair value of derivative contracts are recognized currently in earnings.  The cash flows of all of our commodity derivative contracts are included in Net cash provided by operating activities on the statement of cash flows.
	Commodity Derivatives.  We have entered into commodity swap contracts to manage a portion of our exposure to commodity price risk from sales of oil through December 2014.  While these contracts are intended to reduce the effects of price volatility, they may also limit future income from favorable price movements.  During the nine months ended September 30, 2013 and 2012, our derivative contracts consisted entirely of crude oil swap contracts.  The crude oil swap contracts are comprised of a portion based on Brent crude oil prices and a portion based on West Texas Intermediate (“WTI”) crude oil prices.  The Brent based swap contracts are priced off the Brent crude oil price quoted on the IntercontinentalExchange, known as ICE.  The WTI based swap contracts are priced off the New York Mercantile Exchange, known as NYMEX.  Although our Gulf of Mexico crude oil is based off the WTI crude oil price plus a premium, the realized prices received for our Gulf of Mexico crude oil have been closer to the Brent crude oil price because of competition with foreign supplied crude oil, which is based off the Brent crude oil price.  Therefore, a portion of the swap oil contracts are priced off the Brent crude oil price to mitigate a portion of the price risk associated with our Gulf of Mexico crude oil production.
	As of September 30, 2013, our open commodity derivative contracts were as follows:
			Swaps – Oil
			Priced off Brent (ICE)						Priced off WTI (NYMEX)
	Termination Period		Notional		Weighted				Notional	Weighted
			Quantity (Bbls)		Average				Quantity (Bbls)	Average
					Contract Price					Contract Price
	2013:00:00	4th quarter	294,400		$		101.98		520,000	$	97.38
	2014:00:00	1st quarter	180,000				97.38		762,000		97.39
		2nd quarter	172,900				97.38		455,000		97.17
		3rd quarter	165,600				97.38		155,000		97.00
		4th quarter	156,400				97.37		—		—
			969,300		$		98.77		1,892,000	$	97.30
	Bbls =font> barrels
	The following balance sheet line items included amounts related to the estimated fair value of our open derivative contracts as indicated in the following table (in thousands):
		September 30,			December 31,
		2013			2012
	Prepaid and other assets	$	317		$		—
	Accrued liabilities		8,611				6,355
	Other liabilities (noncurrent)		439				3,046
	Changes in the fair value of our commodity derivative contracts are recognized currently in earnings and were as follows (in thousands):
		Three Months Ended								Nine Months Ended
		September 30,								September 30,
		2013				2012				2013			2012
	Derivative (gain) loss:
	Realized	$	4,545			$		875		$	6,855			$	6,960
	Unrealized		11,114					23,784			(669	)			7,461
	Total	$	15,659			$		24,659		$	6,186			$	14,421
	Offsetting Commodity Derivatives.  As of September 30, 2013 and December 31, 2012, all of our derivative agreements allowed for netting of derivative gains and losses upon settlement.  In general, the terms of the agreements provide for offsetting of amounts payable or receivable between us and the counterparty, at the election of both parties, for transactions that occur on the same date and in the same currency.  If an event of default were to occur causing an acceleration of payment under our revolving bank credit facility, that event may also trigger an acceleration of settlement of our derivative instruments.   If we were required to settle all of our open derivative instruments, we would be able to net payments and receipts per counterparty pursuant to the derivative agreements.  Although our derivative agreements allow for netting, which would allow for recording assets and liabilities per counterparty on a net basis, we account for our derivative contracts on a gross basis per contract as either an asset or liability.
	The following table presents disclosures required by ASU 2011-11 and ASU 2013-01 and provides a reconciliation of the gross assets and liabilities reflected in the balance sheet and the potential effects of master netting agreements on the fair value of open derivative contracts as of September 30, 2013 (in thousands):
			Derivative					Derivative
			Assets					Liabilities
	Gross amounts presented in the balance sheet	$	317			$		9,050
	Amounts not offset in the balance sheet		(317	)				(317	)
	Net amounts	$	—			$		8,733
	There were no potential effects of master netting agreements on the fair value of open derivative contracts as of December 31, 2012 due to all open derivative contracts being valued as liabilities.

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2013
Long-Term Debt	'
	6.  Long-Term Debt
	Our long-term debt was as follows (in thousands):
		September 30,		December 31,
		2013		2012
	8.50% Senior Notes	$	900,000	$	900,000
	Debt premiums, net of amortization		15,984		17,611
	Revolving bank credit facility		137,000		170,000
	Total long-term debt		1,052,984		1,087,611
	Current maturities of long-term debt		—		—
	Long-term debt, less current maturities	$	1,052,984	$	1,087,611
	At September 30, 2013 and December 31, 2012, the balance outstanding of our senior notes, which bear an annual interest rate of 8.50% and mature on June 15, 2019 (the “8.50% Senior Notes”), was classified as long-term at their carrying value.  Interest on the 8.50% Senior Notes is payable semi-annually in arrears on June 15 and December 15.  The estimated annual effective interest rate on the 8.50% Senior Notes is 8.4%, which includes amortization of debt issuance costs and premiums.  We are subject to various financial and other covenants under the indenture governing the 8.50% Senior Notes and we were in compliance with those covenants as of September 30, 2013.
	The Fourth Amended and Restated Credit Agreement (the “Credit Agreement”) governs our revolving bank credit facility and terminates on May 5, 2015.  Borrowings under our revolving bank credit facility are secured by our oil and natural gas properties.  Availability under such facility is subject to a semi-annual redetermination of our borrowing base that occurs in the spring and fall of each year and is calculated by our lenders based on their evaluation of our proved reserves and their own internal criteria.  See Note 13 for information regarding a new credit agreement executed subsequent to September 30, 2013.
	At September 30, 2013 and December 31, 2012, we had $0.1 million of letters of credit outstanding under the revolving bank credit facility.  The estimated annual effective interest rate was 3.9% for the nine months ended September 30, 2013 for borrowings under the revolving bank credit facility.  The estimated annual effective interest rate includes amortization of debt issuance costs and excludes commitment fees and other costs.  As of September 30, 2013, our borrowing base was $800.0 million and our borrowing availability was $662.9 million.
	Under the Credit Agreement, we are subject to various financial covenants calculated as of the last day of each fiscal quarter, including a minimum current ratio and a maximum leverage ratio, each as defined in the Credit Agreement.  We were in compliance with all applicable covenants of the Credit Agreement as of September 30, 2013.
	For information about fair value measurements for our 8.50% Senior Notes and revolving bank credit facility, refer to Note 7.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Measurements	'
	7.  Fair Value Measurements
	We measure the fair value of our derivative financial instruments by applying the income approach, using models with inputs that are classified within Level 2 of the valuation hierarchy.  The inputs used for the fair value measurement of our derivative financial instruments are the exercise price, the expiration date, the settlement date, notional quantities, the implied volatility, the discount curve with spreads and published commodity futures prices.  The fair value of our 8.50% Senior Notes is based on quoted prices and the market is not an active market; therefore, the fair value is classified within Level 2.  The carrying amount of debt under our revolving bank credit facility approximates fair value because the interest rates are variable and reflective of market rates.
	The following table presents the fair value of our derivative financial instruments, 8.50% Senior Notes and revolving bank credit facility for the periods indicated (in thousands).
			September 30, 2013					December 31, 2012
		Hierarchy	Assets		Liabilities				Assets			Liabilities
	Derivatives	Level 2	$	317		$	9,050			$	—		$	9,401
	8.50% Senior Notes	Level 2		—			977,625				—			963,000
	Revolving bank credit facility	Level 2		—			137,000				—			170,000
	As described in Note 5, our derivative financial instruments are reported in the balance sheet at fair value and changes in fair value are recognized currently in earnings.  The 8.50% Senior Notes and revolving bank credit facility are reported in the balance sheet at their carrying value as described in Note 6.

ShareBased_Compensation_and_Ca

Share-Based Compensation and Cash-Based Incentive Compensation	9 Months Ended
	Sep. 30, 2013
Share-Based Compensation and Cash-Based Incentive Compensation	'
	8.  Share-Based Compensation and Cash-Based Incentive Compensation
	In 2010, the W&T Offshore, Inc. Amended and Restated Incentive Compensation Plan (the “Plan”) was approved by our shareholders and amendments to the Plan were approved by our shareholders on May 7, 2013.  As allowed by the Plan, in 2013, 2012 and in 2011, the Company granted restricted stock units (“RSUs”) to certain of its employees.  RSUs are a long-term compensation component of the Plan, which are granted to only certain employees, and are subject to adjustments at the end of the applicable performance period based on the achievement of certain predetermined criteria.  Certain RSUs granted in 2013 (the “2013 RSUs”) are subject to performance criteria of Adjusted EBITDA, defined as  net income before income tax expense, net interest expense, depreciation, depletion, amortization, accretion and certain other items, adjusted EBITDA as a percent of total revenue (“Adjusted EBITDA Margin”) and total shareholder return (“TSR”).  The RSUs granted in 2012 (the “2012 RSUs”) are subject to performance criteria of earnings per share and TSR, while the RSUs granted in 2011 (the “2011 RSUs”) are subject to only earnings per share performance measurement.  In 2013 and in prior years, restricted stock was granted to the Company’s non-employee directors under the Director Compensation Plan.  The restricted stock and RSUs each vest at the end of specified service periods.  In addition to share-based compensation, the Company may grant to its employees cash-based incentive awards, which are a short-term component of the Plan and are based on the Company and the employee achieving certain predetermined performance criteria.
	We recognize compensation cost for share-based payments to employees and non-employee directors over the period during which the recipient is required to provide service in exchange for the award, based on the fair value of the equity instrument on the date of grant.  We are also required to estimate forfeitures, resulting in the recognition of compensation cost only for those awards that are expected to actually vest.
	On May 7, 2013, after receiving shareholder approval, 4,000,000 shares of common stock were added to the amount available for issuance under the Plan.  At September 30, 2013, there were 5,393,602 shares of common stock available for issuance in satisfaction of awards under the Plan and 519,379 shares of common stock available for issuance in satisfaction of awards under the Director Compensation Plan. The shares available for both plans are reduced when restricted stock is granted.  RSUs will reduce the shares available in the Plan only when RSUs are settled in shares of common stock.  Although the Company has the option to settle RSUs in stock or cash at vesting, only common stock has been used to settle vested RSUs to date.
	Restricted Stock.   As of September 30, 2013, all of the unvested restricted shares outstanding were issued to the non-employee directors.  Restricted shares are subject to forfeiture until vested and cannot be sold, transferred or disposed of during the restricted period. The holders of restricted shares generally have the same rights as a shareholder of the Company with respect to such shares, including the right to vote and receive dividends or other distributions paid with respect to the shares.  The fair value of restricted stock was estimated by using the Company’s closing price on the grant date.
	A summary of activity in 2013 related to restricted stock is as follows:
		Restricted Stock
		Shares		Weighted
				Average
				Grant Date
				Fair Value
				Per Share
	Outstanding restricted shares, December 31, 2012	43,687		$	18.69
	Granted	27,450			12.75
	Vested	(27,297	)		17.09
	Outstanding restricted shares, September 30, 2013	43,840		$	15.96
	Subject to the satisfaction of service conditions, the outstanding restricted shares issued to the non-employee directors as of September 30, 2013 are expected to vest as follows:
		Shares
	2014	19,445
	2015	15,245
	2016	9,150
	Total	43,840
	The grant date fair value of restricted shares granted during the nine months ended September 30, 2013 and 2012 was $0.3 million and $0.4 million, respectively.  The fair value of restricted shares that vested during the nine months ended September 30, 2013 and 2012 was $0.4 million and $0.5 million, respectively.
	Restricted Stock Units.  As of September 30, 2013, the Company had outstanding RSUs issued to certain employees.  Certain 2013 RSUs are subject to pre-defined share performance measures comprised of Adjusted EBITDA and Adjusted EBITDA Margin for 2013 and TSR for defined periods in 2013, 2014 and 2015; therefore, no portion has been determined to be eligible for vesting as of September 30, 2013.  A portion of the 2012 RSUs remains subject to the certain pre-defined performance measures of TSR for the defined periods in 2013 and 2014; therefore, this portion will be determined whether eligible for vesting at the end of the respective performance periods.  TSR is determined based upon the change in the entity’s stock price and dividends for the performance period.  The TSR targets are the ranking of the Company’s TSR compared to the TSR of certain peer companies.  The TSR components have an issuance scale from 0% to 200%.  The portion of RSUs subject to TSR performance measurement is disclosed in the second table below.
	The fair value for the 2013 RSUs was determined separately for the component related to the Company specific performance measures (Adjusted EBITDA and Adjusted EBITDA Margin) and the component related to TSR targets.  The fair value of the 2013 RSUs component related to the Company specific performance measures was determined using the Company’s closing price on the grant date.  The fair value for the 2013 RSUs component related to TSR targets was determined by using a Monte Carlo simulation probabilistic model.  The inputs used in the probabilistic model for the Company and the peer companies were: average closing stock prices during January 2013; risk-free interest rates using the London Interbank Offered Rate (“LIBOR”) ranging from 0.27% to 0.91% over the service period; expected volatilities ranging from 30% to 63%; expected dividend yields ranging from 0.0% to 3.1%; and correlation factors ranging from (84%) to 95%.  The expected volatilities, expected dividends and correlation factors were developed using historical data.
	A methodology similar to that employed for the 2013 RSUs was used to determine the fair value for the 2012 RSUs.  The inputs used in the probabilistic model for the Company and the peer companies were: average closing stock prices during January 2012; risk-free interest rates using the LIBOR ranging from 0.15% to 0.72% over the service period; expected volatilities ranging from 33% to 74%; expected dividend yields ranging from 0.0% to 2.5%; and correlation factors ranging from (67%) to 94%.  The expected volatilities, expected dividends and correlation factors were developed using historical data.  The fair value of the 2011 RSUs, which contained only Company-specific performance measures, was estimated by using the Company’s closing price on the grant date.
	The majority of RSUs are subject to predetermined performance criteria and all RSUs are subject to service requirements prior to vesting.  All RSUs awarded are subject to forfeiture until vested and cannot be sold, transferred or otherwise disposed of during the restricted period.  Dividend equivalents are earned at the same rate as dividends paid on our common stock after achieving the specified performance requirement for that component of the RSUs.
	A summary of activity in 2013 related to RSUs is as follows:
		Restricted Stock Units
		Units		Weighted
				Average
				Grant Date
				Fair Value
				Per Unit
	Outstanding RSUs, December 31, 2012	969,820		$	22.70
	Granted	969,919			13.23
	Forfeited	(33,042	)		18.86
	Outstanding RSUs, September 30, 2013	1,906,697		$	17.95
	Subject to the satisfaction of service conditions, the RSUs outstanding as of September 30, 2013 are eligible to vest in the year indicated in the table below:
		Units
	2013 – subject to service requirements	470,536
	2014 – subject to service requirements	335,555
	2014 – subject to service and other requirements (1)	138,330
	2015 – subject to service requirements	23,500
	2015 – subject to service and other requirements  (2)	657,143
	2015 – subject to service and other requirements  (3)	281,633
	Total	1,906,697
	(1	)		In addition to service requirements, these RSUs are also subject to TSR performance requirements not yet measureable, with awards ranging from 0% to 150% of amounts granted.
	(2	)		In addition to service requirements, these RSUs are also subject to certain Company-specific performance requirements not yet measureable, with awards ranging from 0% to 150% of amounts granted.
	(3	)		In addition to service requirements, these RSUs are also subject to TSR performance requirements not yet measureable, with awards ranging from 0% to 200% of amounts granted.
	The grant date fair value of RSUs granted during the nine months ended September 30, 2013 and 2012 was $12.8 million and $14.2 million, respectively.  During the nine months ended September 30, 2013 and 2012, there was no vesting of RSUs.
	Share-Based Compensation.
	A summary of incentive compensation expense under share-based payment arrangements and the related tax benefit is as follows (in thousands):
		Three Months Ended								Nine Months Ended
		September 30,								September 30,
		2013				2012				2013					2012
	Share-based compensation expense from:
	Restricted stock	$		99		$	110		$			297		$		324
	Restricted stock units			3,408			3,209					8,160				8,813
	Total	$		3,507		$	3,319		$			8,457		$		9,137
	Share-based compensation tax benefit:
	Tax benefit computed at the statutory rate	$		1,227		$	1,162		$			2,960		$		3,198
	Unrecognized Share-Based Compensation.  As of September 30, 2013, unrecognized share-based compensation expense related to our outstanding restricted shares and RSUs was $0.6 million and $16.1 million, respectively.   Unrecognized share-based compensation expense will be recognized through April 2016 for restricted shares and November 2015 for RSUs.
Cash-Based Incentive Compensation. As defined by the Plan, annual incentive awards may be granted to eligible employees payable in cash.  These awards are performance-based awards consisting of one or more business criteria or individual performance criteria and a targeted level or levels of performance with respect to each of such criteria.  Generally, the performance period is the calendar year and determination and payment is made in cash in the first quarter of the following year.
Share-Based Compensation and Cash-Based Incentive Compensation Expense.
A summary of incentive compensation expense is as follows (in thousands):
	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2013				2012		2013			2012
Share-based compensation expense included in:
General and administrative - charge to operating income	$		3,507		$	3,319	$	8,457		$		9,137
Cash-based incentive compensation included in:
Lease operating expense			724			947		2,864				2,846
General and administrative			2,191			3,048		7,745				4,926
Total charged to operating income			2,915			3,995		10,609				7,772
Total incentive compensation charged to operating income	$		6,422		$	7,314	$	19,066		$		16,909

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Taxes	'
	9.  Income Taxes
	Income tax expense of $8.0 million and $35.4 million was recorded during the three and nine months ended September 30, 2013, respectively.  Our effective tax rate for the three and nine months ended September 30, 2013 was 36.1% and 35.9%, respectively, and differed from the federal statutory rate of 35.0% primarily as a result of state income taxes.  Income tax benefit of $2.2 million and income tax expense of $34.0 million was recorded during the three and nine months ended September 30, 2012, respectively.  The effective tax rate for the three months ended September 30, 2012 was 59.7%, which exceeded the amount computed at the statutory rate as a result of a decrease in our full year forecasted effective tax rate.  Our effective tax rate for the nine months ended September 30, 2012 was 38.0% and differed from the federal statutory rate primarily as a result of the recapture of deductions for qualified domestic production activities under Section 199 of the IRC as a result of loss carrybacks to prior years.
	During the three and nine months ended September 30, 2013, we received refunds of $59.1 million and of which $9.5 million of these refunds have been accounted for as unrecognized tax benefits.  We recognize interest and penalties related to unrecognized tax benefits in income tax expense.  During the three months and nine months ended September 30, 2013, we had less than $0.1 million of accrued interest related to our unrecognized tax benefit.  We did not have an unrecognized tax benefit at December 31, 2012.  As of September 30, 2013 and December 31, 2012, we had a valuation allowance related to state net operating losses.  The realization of these assets depends on recognition of sufficient future taxable income in specific tax jurisdictions in which those temporary differences or net operating losses are deductible.  The tax years from 2009 through 2012 remain open to examination by the tax jurisdictions to which we are subject.

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share	'
	10.  Earnings Per Share
	The following table presents the calculation of basic and diluted earnings per common share (in thousands, except per share amounts):
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
		2013		2012			2013		2012
	Net income (loss)	$	14,194	$	(1,471	)	$	63,208	$	55,315
	Less portion allocated to nonvested shares		159		90			713		1,128
	Net income (loss) allocated to common shares	$	14,035	$	(1,561	)	$	62,495	$	54,187
	Weighted average common shares outstanding		75,233		74,327			75,221		74,315
	Basic and diluted earnings (loss) per common share	$	0.19	$	(0.02	)	$	0.83	$	0.73
	Shares excluded due to being anti-dilutive (weighted-average)		851		1,866			860		1,823

Dividends

Dividends	9 Months Ended
	Sep. 30, 2013
Dividends	'
	11.  Dividends
	During the nine months ended September 30, 2013 and 2012, we paid regular cash dividends per common share of $0.26 and $0.24, respectively.  On November 6, 2013, our board of directors declared a cash dividend of $0.10 per common share, payable on December 3, 2013 to shareholders of record on November 18, 2013.

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2013
Contingencies	'
	12.  Contingencies
	Cameron Parish Louisiana Claim.  Since 2009, certain Cameron Parish landowners have filed suits in the 38th Judicial District Court, Cameron Parish, Louisiana against the Company and its Chief Executive Officer, Tracy W. Krohn, as well as several other defendants unrelated to us.  In their lawsuits, plaintiffs alleged that property they own has been contaminated or otherwise damaged by the defendants’ oil and gas exploration and production activities and they are seeking compensatory and punitive damages.  During 2012 and for the nine months ended September 30, 2013, we settled claims with certain landowners and paid $10.0 million and $1.3 million, respectively.
	Qui Tam Litigation.  On September 21, 2012, the Company was served with a complaint in a qui tam action filed under the federal False Claims Act by an employee of a Company contractor.  The lawsuit, United States ex rel. Comeaux v. W&T Offshore, Inc., et al.; CA No. 10-494, was filed in the United States District Court for the Eastern District of Louisiana, against the Company and three other working interest owners related to claims associated with three of the Company’s operated production platforms.  A qui tam action, also known as a “whistleblower” action, is a lawsuit brought by a private citizen seeking civil penalties or damages against a person or company on behalf of the government for alleged violations of law.  If the claims are successful, the person filing the suit may recover a percentage of the damages or penalty from the lawsuit as a reward for exposing a wrongdoing and recovering funds on behalf of the government. This matter was more fully described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
	On November 5, 2013, the court granted the Company’s motion to dismiss and the complaint was dismissed with prejudice.  If a motion for reconsideration or an appeal is made, the Company intends to vigorously defend the claims made in this lawsuit. The Company has determined that the likelihood of an adverse outcome is remote, and accordingly, no accrual has been made.
	Insurance Claims. During the fourth quarter of 2012, underwriters of W&T’s excess liability policies (“Excess Policies”) (Indemnity Insurance Company of North America, New York Marine & General Insurance Company, Navigators Insurance Company, XL Specialty Insurance Company and Liberty Mutual Insurance Co.) filed declaratory judgment actions in the United States District Court for the Southern District of Texas seeking a determination that our Excess Policies cover removal of wreck and debris claims arising from Hurricane Ike to the extent we have first exhausted the limits of our Energy Package (defined as certain insurance policies relating to our oil and gas properties) with only removal of wreck and debris claims.  The court consolidated the various suits filed by the underwriters.  W&T has not yet filed any claim under such Excess Policies.  As of September 30, 2013, we have spent $45.3 million to date and expect to incur an additional $2.1 million of costs for removal of wreck associated with platforms damaged by Hurricane Ike. In January 2013, we filed a motion for summary judgment seeking the court’s determination that such Excess Policies do not require us to exhaust the limits of our Energy Package policies with only removal of wreck and debris claims.  On July 31, 2013, the District Court ruled in favor of the underwriters, adopting their position that the Excess Policies cover removal of wreck and debris claims only to the extent the limits of our Energy Package policies have been exhausted with removal of wreck and debris claims.  We disagree with the Court’s ruling and have appealed the decision.  Removal of wreck costs are recorded in Oil and natural gas properties and equipment on the Balance Sheet.  If we are successful in our appeal, any recoveries from claims made on these Excess Policies related to this issue will be recorded as reductions in this line item, which will reduce the Company’s DD&A rate.
	Royalties.  In 2009, the Company recognized $5.3 million in allowable reductions of cash payments for royalties owed to the Office of Natural Resources Revenue (the “ONRR”) for transportation of their deepwater production through our subsea pipeline systems.  In 2010, the ONRR audited the calculations and support related to this usage fee, and in the third quarter of 2010, we were notified that the ONRR had disallowed approximately $4.7 million of the reductions taken.  We recorded a reduction to other revenue of $4.7 million in the third quarter of 2010 to reflect this disallowance; however, we disagree with the position taken by the ONRR and we are pursuing our claim to resolve the matter.
	Other Claims.  We are a party to various pending or threatened claims and complaints seeking damages or other remedies concerning our commercial operations and other matters in the ordinary course of our business.  In addition, claims or contingencies may arise related to matters occurring prior to our acquisition of properties or related to matters occurring subsequent to our sale of properties.  In certain cases, we have indemnified the sellers of properties we have acquired, and in other cases, we have indemnified the buyers of properties we have sold.  We are also subject to federal and state administrative proceedings conducted in the ordinary course of business.  Although we can give no assurance about the outcome of pending legal and federal or state administrative proceedings and the effect such an outcome may have on us, management believes that any ultimate liability resulting from the outcome of such proceedings, to the extent not otherwise provided for or covered by insurance, will not have a material adverse effect on our consolidated financial position, results of operations or liquidity.
	Contingent Liability Recorded.  Recognized expenses related to accrued and settled claims, complaints and fines were $0.3 million for the nine months ended September 30, 2013 and $8.8 million for the nine months ended September 30, 2012.  These expenses are reported in General and administrative expenses on the statement of income and reflect the items noted above and other various claims and complaints.  As of September 30, 2013 and December 31, 2012, we have recorded $0.1 million and $1.3 million, respectively, which are included in Accrued liabilities on the balance sheet, for the loss contingencies matters that include the events described above and other minor environmental and litigation matters which we are addressing in the normal course of business.

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2013
Subsequent Events	'
	13.  Subsequent Events
	2013 Acquisition.  On October 17, 2013, W&T entered into a purchase and sale agreement to acquire certain oil and natural gas property interests from Callon Petroleum Operating Company (“Callon”), referred to herein as the “Callon Properties.” Pursuant to the purchase and sale agreement, transactions covering the transfer of certain properties that had no preferential rights were consummated on November 5, 2013 (the “First Closing”).  The First Closing included the majority of the value of the Callon Properties.  A final close is expected to be consummated by the end of November 2013 for properties that have preferential rights which are not exercised.  The effective date of the transaction was July 1, 2013.  After customary effective date adjustments and closing adjustments, the cash consideration paid was $76.4 million, which is subject to further post-closing adjustments.  In addition, we assumed the related ARO, which is set forth in the table below.  The acquisition was funded from borrowings under our revolving bank credit facility and cash on hand. The First Closing of the Callon Properties consists of a 15% working interest in the Medusa field (deepwater Mississippi Canyon blocks 582 and 583), interest in associated production facilities and various interests in other non-operated fields. All of these properties are located in the Gulf of Mexico.
	The following table presents the preliminary purchase price allocation, including estimated adjustments, for the acquisition of the Callon Properties including in the First Closing (in thousands):
	Oil and natural gas properties and equipment	$	79,136
	Asset retirement obligations – current		(15	)
	Asset retirement obligations – non-current		(2,713	)
	Total cash paid	$	76,408
	The acquisition was recorded at fair value, which was determined by applying the market and income approaches using Level 3 inputs.  The Level 3 inputs were: (i) analysis of comparable transactions obtained from various third-parties, (ii) estimates of ultimate recoveries of reserves and (iii) estimates of discounted cash flows based on estimated reserve quantities, reserve categories, timing of production, costs to produce and develop reserves, future prices, ARO and discount rates.  The estimates and assumptions were determined by management and third-parties.  The fair value is based on subjective estimates and assumptions, which are inherently imprecise, and the actual realized values could vary significantly from these estimates.  No goodwill was recorded for the Callon Properties acquisition related to the First Closing.
	Revenues, Net Income and Pro Forma Financial Information — Unaudited
	The Callon Properties were not included in our consolidated results for the quarter ended September 30, 2013 as the acquisition closing date was subsequent to such date.   There were no expenses associated with acquisition activities and transition activities related to the acquisition of the Callon Properties for the nine months ended September 30, 2013.
	The unaudited pro forma financial information was computed as if the acquisition of the Callon Properties had been completed on January 1, 2012.  The financial information was derived from W&T’s unaudited historical condensed consolidated financial statements and Callon Properties’ unaudited historical financial statement for the periods presented.
	The pro forma adjustments were based on estimates by management and information believed to be directly related to the purchase of the Callon Properties.  The pro forma financial information is not necessarily indicative of the results of operations had the purchase occurred on January 1, 2012.  If the transaction had been in effect for the periods indicated, the results may have been substantially different.  For example, we may have operated the assets differently than Callon; the realized sales prices for oil, NGLs and natural gas may have been different; and the costs of operating the Callon Properties may have been different.  The properties used in the pro forma financial information are from the First Closing and exclude properties with outstanding preferential rights by third parties.
	The following table presents a summary of our pro forma financial information (in thousands except earnings per share):
		Three Months Ended								Nine Months Ended
		September 30,								September 30,
			2013			2012						2013			2012
	Revenues	$	254,092		$	197,076		$				766,801		$	670,881
	Net income		16,513			858						69,310			63,801
	Basic and diluted earnings per common share		0.22			0.01						0.91			0.84
	For the pro forma financial information, certain information was derived from financial records and certain information was estimated.
	The following table presents incremental items included in the pro forma information reported above for the Callon Properties included in the First Closing (in thousands):
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
			2013			2012		2013					2012
	Revenues (a)	$	9,537		$	11,130	$	27,641			$		33,536
	Direct operating expenses (a)		1,459			1,614		4,915					4,628
	Insurance costs (b)		510			510		1,531					1,214
	DD&A (c)		3,615			4,822		10,735					13,095
	Interest expense (d)		382			382		1,146					1,146
	Capitalized interest (e)		4			219		(74	)				398
	Income tax expense (f)		1,248			1,254		3,286					4,569
	The sources of information and significant assumptions are described below:
	(a)              Revenues and direct operating expenses for the Callon Properties were derived from the unaudited historical financial records of Callon.
	(b)              Incremental costs for insurance were estimated from the incremental costs to add the Callon Properties included in the First Close to W&T’s insurance programs.  The direct operating expenses for the Callon Properties described above exclude insurance costs.
	(c)              DD&A was estimated using the full-cost method and determined as the incremental DD&A expense due to adding the Callon Properties’ costs, reserves and production into our currently existing full cost pool in order to compute such amounts.  The purchase price allocation included $7.2 million that was allocated to the pool of unevaluated properties for oil and natural gas interests.  Accordingly, no DD&A expense was estimated for the unevaluated properties.  ARO was estimated by W&T management.
	(d)              The acquisition was assumed to be funded entirely with borrowed funds.  Interest expense was computed using assumed borrowings of $76.4 million, which equates to the cash component of the transaction, and an interest rate of 2.0%, which equates to the rates applied to incremental borrowings on the revolving bank credit facility.
	(e)              The change to capitalized interest was computed for the addition to the pool of unevaluated properties and the capitalization interest rate was adjusted for the assumed borrowings.  Positive amounts represent increases to net expenses.  The negative amount represents a decrease to net expenses.
	(f)              Income tax expense was computed using the 35% federal statutory rate.
	(g)              The 2012 periods above do not include any pro forma adjustments related to the 2012 acquisition as described in Note 2.
	Revolving Bank Credit Facility.  On November 8, 2013, the Company entered into the Fifth Amended and Restated Credit Agreement (the “New Credit Agreement”).  The New Credit Agreement increased the total credit facility amount from $900.0 million to $1.2 billion and matures on November 8, 2018.  The borrowing base was not changed and remains at $800.0 million.  The proved reserves associated with the Callon Properties were not considered for purposes of the redetermination of the borrowing base.  The New Credit Agreement increased the capacity to issue letters of credit from $100.0 million to $300.0 million.  The financial covenant for the maximum leverage ratio of total debt to EBITDA, as defined in the New Credit Agreement, was increased from 3.0 to 1.0 to 3.5 to 1.0.  The other financial covenant, the minimum current ratio, as defined in the New Credit Agreement, remains at 1.0 to 1.0.  Interest rates, or margins, were decreased for certain categories.  These categories are determined by the Company’s borrowing base utilization.  Interest rates were unchanged for all the other categories.  In addition, there were other minor changes from the previous Credit Agreement that were favorable to the Company.  All other terms and conditions were substantially the same as under the previous Credit Agreement.

Supplemental_Guarantor_Informa

Supplemental Guarantor Information	9 Months Ended
	Sep. 30, 2013
Supplemental Guarantor Information	'
	W&T OFFSHORE, INC. AND SUBSIDIARIES
	NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS – (Continued)
	(Unaudited)
	14.  Supplemental Guarantor Information
	Our payment obligations under the Credit Agreement as of September 30, 2013 were, and our payment obligations under the 8.50% Senior Notes and the New Credit Agreement (see Notes 6 and 13) are, fully and unconditionally guaranteed by certain of our wholly-owned subsidiaries, including W&T Energy VI, LLC and W&T Energy VII, LLC (together, the “Guarantor Subsidiaries”).  W&T Energy VII, LLC does not currently have any active operations or contain any assets.  Guarantees of the 8.50% Senior Notes will be released under certain circumstances, including:
	(1) in connection with any sale or other disposition of all or substantially all of the assets of a Guarantor Subsidiary (including by way of merger or consolidation) to a person that is not (either before or after giving effect to such transaction) the Company or a Restricted Subsidiary (as such term is defined in the indenture governing the 8.50% Senior Notes) of the Company, if the sale or other disposition does not violate the “Asset Sales” provisions of the indenture;
	(2) in connection with any sale or other disposition of the capital stock of such Guarantor Subsidiary to a person that is not (either before or after giving effect to such transaction) the Company or a Restricted Subsidiary of the Company, if the sale or other disposition does not violate the “Asset Sales” provisions of the indenture and the Guarantor Subsidiary ceases to be a subsidiary of the Company as a result of such sales or disposition;
	(3) if such Guarantor Subsidiary is a Restricted Subsidiary and the Company designates such Guarantor Subsidiary as an Unrestricted Subsidiary in accordance with the applicable provisions of the indenture;
	(4) upon Legal Defeasance or Covenant Defeasance (as such terms are defined in the indenture) or upon satisfaction and discharge of the indenture;
	(5) upon the liquidation or dissolution of such Guarantor Subsidiary, provided no event of default has occurred and is continuing; or
	(6) at such time as such Guarantor Subsidiary is no longer required to be a Guarantor Subsidiary of the 8.50% Senior Notes as described in the indenture, provided no event of default has occurred and is continuing.
	The following unaudited condensed consolidating financial information presents the financial condition, results of operations and cash flows of W&T Offshore, Inc. (the “Parent Company”) and the Guarantor Subsidiaries, together with consolidating adjustments necessary to present the Company’s results on a consolidated basis.
	Condensed Consolidating Balance Sheet as of September 30, 2013
		Parent			Guarantor				Eliminations				Consolidated
		Company			Subsidiaries								W&T
													Offshore, Inc.
		(In thousands)
	Assets
	Current assets:
	Cash and cash equivalents	$	15,227		$		—		$		—		$	15,227
	Receivables:
	Oil and natural gas sales		66,953				18,301				(33	)		85,221
	Joint interest and other		31,492				—				—			31,492
	Total receivables		98,445				18,301				(33	)		116,713
	Restricted cash and cash equivalents		16,459				—				—			16,459
	Prepaid expenses and other assets		152,739				3,991				(123,880	)		32,850
	Total current assets		282,870				22,292				(123,913	)		181,249
	Property and equipment – at cost:
	Oil and natural gas properties and equipment		6,703,175				416,911				—			7,120,086
	Furniture, fixtures and other		21,325				—				—			21,325
	Total property and equipment		6,724,500				416,911				—			7,141,411
	Less accumulated depreciation, depletion and amortization		4,690,550				260,218				—			4,950,768
	Net property and equipment		2,033,950				156,693				—			2,190,643
	Restricted deposits for asset retirement obligations		34,966				—				—			34,966
	Deferred income taxes		—				4,549				(4,549	)		—
	Other assets		481,029				441,908				(906,095	)		16,842
	Total assets	$	2,832,815		$		625,442		$		(1,034,557	)	$	2,423,700
	Liabilities and Shareholders’ Equity
	Current liabilities:
	Accounts payable	$	130,021		$		—		$		(33	)	$	129,988
	Undistributed oil and natural gas proceeds		40,989				289				—			41,278
	Asset retirement obligations		95,014				—				—			95,014
	Accrued liabilities		45,272				129,656				(123,880	)		51,048
	Total current liabilities		311,296				129,945				(123,913	)		317,328
	Long-term debt		1,052,984				—				—			1,052,984
	Asset retirement obligations, less current portion		235,782				31,311				—			267,093
	Deferred income taxes		181,953				—				(4,549	)		177,404
	Other liabilities		457,768				—				(441,909	)		15,859
	Shareholders’ equity:
	Common stock		1				—				—			1
	Additional paid-in capital		404,604				231,759				(231,759	)		404,604
	Retained earnings		212,594				232,427				(232,427	)		212,594
	Treasury stock, at cost		(24,167	)			—				—			(24,167	)
	Total shareholders’ equity		593,032				464,186				(464,186	)		593,032
	Total liabilities and shareholders’ equity	$	2,832,815		$		625,442		$		(1,034,557	)	$	2,423,700
	21
	W&T OFFSHORE, INC. AND SUBSIDIARIES
	NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS – (Continued)
	(Unaudited)
	Condensed Consolidating Balance Sheet as of December 31, 2012
		Parent			Guarantor				Eliminations				Consolidated
		Company			Subsidiaries								W&T
													Offshore, Inc.
	(In thousands)
Assets
Current assets:
Cash and cash equivalents	$	12,245		$		—		$		—		$	12,245
Receivables:
Oil and natural gas sales		80,729				17,004				—			97,733
Joint interest and other		56,439				—				—			56,439
Income taxes		163,750				—				(115,866	)		47,884
Total receivables		300,918				17,004				(115,866	)		202,056
Prepaid expenses and other assets		25,822				—				—			25,822
Total current assets		338,985				17,004				(115,866	)		240,123
Property and equipment – at cost:
Oil and natural gas properties and equipment		6,356,529				337,981				—			6,694,510
Furniture, fixtures and other		21,786				—				—			21,786
Total property and equipment		6,378,315				337,981				—			6,716,296
Less accumulated depreciation, depletion and amortization		4,461,886				193,955				—			4,655,841
Net property and equipment		1,916,429				144,026				—			2,060,455
Restricted deposits for asset retirement obligations		28,466				—				—			28,466
Deferred income taxes		—				13,509				(13,509	)		—
Other assets		442,540				393,499				(816,096	)		19,943
Total assets	$	2,726,420		$		568,038		$		(945,471	)	$	2,348,987
Liabilities and Shareholders’ Equity
Current liabilities:
Accounts payable	$	123,792		$		93		$		—		$	123,885
Undistributed oil and natural gas proceeds		36,791				282				—			37,073
Asset retirement obligations		92,595				—				35			92,630
Accrued liabilities		20,755				116,132				(115,866	)		21,021
Total current liabilities		273,933				116,507				(115,831	)		274,609
Long-term debt		1,087,611				—				—			1,087,611
Asset retirement obligations, less current portion		262,524				28,934				(35	)		291,423
Deferred income taxes		158,758				—				(13,509	)		145,249
Other liabilities		402,407				—				(393,499	)		8,908
Shareholders’ equity:
Common stock		1				—				—			1
Additional paid-in capital		396,186				231,759				(231,759	)		396,186
Retained earnings		169,167				190,838				(190,838	)		169,167
Treasury stock, at cost		(24,167	)			—				—			(24,167	)
Total shareholders’ equity		541,187				422,597				(422,597	)		541,187
Total liabilities and shareholders’ equity	$	2,726,420		$		568,038		$		(945,471	)	$	2,348,987
22
W&T OFFSHORE, INC. AND SUBSIDIARIES
NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS – (Continued)
(Unaudited)
Condensed Consolidating Statement of Income for the Three Months Ended September 30, 2013
	Parent			Guarantor				Eliminations				Consolidated
	Company			Subsidiaries								W&T
												Offshore, Inc.
	(In thousands)
Revenues	$	195,064		$		49,491		$		—		$	244,555
Operating costs and expenses:
Lease operating expenses		64,952				2,394				—			67,346
Production taxes		1,807				—				—			1,807
Gathering and transportation		2,706				905				—			3,611
Depreciation, depletion, amortization and accretion		80,230				23,913				—			104,143
General and administrative expenses		19,375				649				—			20,024
Derivative loss		15,659				—				—			15,659
Total costs and expenses		184,729				27,861				—			212,590
Operating income		10,335				21,630				—			31,965
Earnings of affiliates		14,032				—				(14,032	)		—
Interest expense:
Incurred		21,373				—				—			21,373
Capitalized		(2,573	)			—				—			(2,573	)
Other income		9,062				—				—			9,062
Income before income tax expense		14,629				21,630				(14,032	)		22,227
Income tax expense		435				7,598				—			8,033
Net income	$	14,194		$		14,032		$		(14,032	)	$	14,194
Condensed Consolidating Statement of Income for the Nine Months Ended September 30, 2013
	Parent			Guarantor				Eliminations				Consolidated
	Company			Subsidiaries								W&T
												Offshore, Inc.
	(In thousands)
Revenues	$	590,492		$		148,668		$		—		$	739,160
Operating costs and expenses:
Lease operating expenses		184,458				10,477				—			194,935
Production taxes		5,375				—				—			5,375
Gathering and transportation		10,099				2,564				—			12,663
Depreciation, depletion, amortization and accretion		244,597				68,314				—			312,911
General and administrative expenses		57,738				3,241				—			60,979
Derivative loss		6,186				—				—			6,186
Total costs and expenses		508,453				84,596				—			593,049
Operating income		82,039				64,072				—			146,111
Earnings of affiliates		41,589				—				(41,589	)		—
Interest expense:
Incurred		64,157				—				—			64,157
Capitalized		(7,537	)			—				—			(7,537	)
Other income		9,075				—				—			9,075
Income before income tax expense		76,083				64,072				(41,589	)		98,566
Income tax expense		12,875				22,483				—			35,358
Net income	$	63,208		$		41,589		$		(41,589	)	$	63,208
23
W&T OFFSHORE, INC. AND SUBSIDIARIES
NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS – (Continued)
(Unaudited)
Condensed Consolidating Statement of Income for the Three Months Ended September 30, 2012
	Parent			Guarantor				Eliminations				Consolidated
	Company			Subsidiaries								W&T
												Offshore, Inc.
	(In thousands)
Revenues	$	141,139		$		44,807		$		—		$	185,946
Operating costs and expenses:
Lease operating expenses		47,353				6,058				—			53,411
Production taxes		1,353				—				—			1,353
Gathering and transportation		2,084				726				—			2,810
Depreciation, depletion, amortization and accretion		58,744				18,718				—			77,462
General and administrative expenses		18,691				—				—			18,691
Derivative loss		24,659				—				—			24,659
Total costs and expenses		152,884				25,502				—			178,386
Operating income (loss)		(11,745	)			19,305				—			7,560
Earnings of affiliates		12,551				—				(12,551	)		—
Interest expense:
Incurred		14,791				—				—			14,791
Capitalized		(3,383	)			—				—			(3,383	)
Other income		202				—				—			202
Income (loss) before income tax expense		(10,400	)			19,305				(12,551	)		(3,646	)
Income tax expense (benefit)		(8,929	)			6,754				—			(2,175	)
Net income (loss)	$	(1,471	)	$		12,551		$		(12,551	)	$	(1,471	)
Condensed Consolidating Statement of Income for the Nine Months Ended September 30, 2012
	Parent			Guarantor				Eliminations				Consolidated
	Company			Subsidiaries								W&T
												Offshore, Inc.
	(In thousands)
Revenues	$	473,297		$		164,048		$		—		$	637,345
Operating costs and expenses:
Lease operating expenses		150,860				19,489				—			170,349
Production taxes		4,174				—				—			4,174
Gathering and transportation		8,788				2,352				—			11,140
Depreciation, depletion, amortization and accretion		189,827				62,067				—			251,894
General and administrative expenses		60,200				2,593				—			62,793
Derivative loss		14,421				—				—			14,421
Total costs and expenses		428,270				86,501				—			514,771
Operating income		45,027				77,547				—			122,574
Earnings of affiliates		50,395				—				(50,395	)		—
Interest expense:
Incurred		43,409				—				—			43,409
Capitalized		(9,899	)			—				—			(9,899	)
Other income		210				—				—			210
Income before income tax expense		62,122				77,547				(50,395	)		89,274
Income tax expense		6,807				27,152				—			33,959
Net income	$	55,315		$		50,395		$		(50,395	)	$	55,315
24
W&T OFFSHORE, INC. AND SUBSIDIARIES
NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS – (Continued)
(Unaudited)
Condensed Consolidating Statement of Cash Flows for the Nine Months Ended September 30, 2013
	Parent			Guarantor				Eliminations				Consolidated
	Company			Subsidiaries								W&T
												Offshore, Inc.
	(In thousands)
Operating activities:
Net income	$	63,208		$		41,589		$		(41,589	)	$	63,208
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion, amortization and accretion		244,597				68,314				—			312,911
Amortization of debt issuance costs and premium		1,366				—				—			1,366
Share-based compensation		8,457				—				—			8,457
Derivative loss		6,186				—				—			6,186
Cash payments on derivative settlements		(6,855	)			—				—			(6,855	)
Deferred income taxes		22,621				8,960				—			31,581
Earnings of affiliates		(41,589	)			—				41,589			—
Changes in operating assets and liabilities:
Oil and natural gas receivables		13,775				(1,264	)			—			12,511
Joint interest and other receivables		24,947				—				—			24,947
Insurance receivables		5,117				—				—			5,117
Income taxes		39,909				13,524				—			53,433
Prepaid expenses and other assets		(6,823	)			(52,400	)			48,408			(10,815	)
Asset retirement obligation settlements		(59,017	)			(171	)			—			(59,188	)
Accounts payable, accrued liabilities and other		81,501				(119	)			(48,408	)		32,974
Net cash provided by operating activities		397,400				78,433				—			475,833
Investing activities:
Investment in oil and natural gas properties and equipment		(344,659	)			(78,433	)			—			(423,092	)
Proceeds from sales of assets and other, net		21,011				—				—			21,011
Change in restricted cash		(16,459	)			—				—			(16,459	)
Purchases of furniture, fixtures and other		(1,327	)			—				—			(1,327	)
Net cash used in investing activities		(341,434	)			(78,433	)			—			(419,867	)
Financing activities:
Borrowings of long-term debt – revolving bank credit facility		335,000				—				—			335,000
Repayments of long-term debt – revolving bank credit facility		(368,000	)			—				—			(368,000	)
Debt issuance costs		(164	)			—				—			(164	)
Dividends to shareholders		(19,570	)			—				—			(19,570	)
Other		(250	)			—				—			(250	)
Net cash used in financing activities		(52,984	)			—				—			(52,984	)
Increase in cash and cash equivalents		2,982				—				—			2,982
Cash and cash equivalents, beginning of period		12,245				—				—			12,245
Cash and cash equivalents, end of period	$	15,227		$		—		$		—		$	15,227
Condensed Consolidating Statement of Cash Flows for the Nine Months Ended September 30, 2012
	Parent				Guarantor			Eliminations				Consolidated
	Company				Subsidiaries							W&T
												Offshore, Inc.
	(In thousands)
Operating activities:
Net income	$	55,315			50,395			(50,395	)		$	55,315
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion, amortization and accretion		189,827			62,067			—				251,894
Amortization of debt issuance costs		2,046			—			—				2,046
Share-based compensation		9,137			—			—				9,137
Derivative loss		14,421			—			—				14,421
Cash payments on derivative settlements		(6,960	)		—			—				(6,960	)
Deferred income taxes		42,816			1,649			—				44,465
Earnings of affiliates		(50,395	)		—			50,395				—
Changes in operating assets and liabilities:
Oil and natural gas receivables		24,162			6,158			—				30,320
Joint interest and other receivables		3,935			—			—				3,935
Insurance receivables		500			—			—				500
Income taxes		(49,830	)		25,503			—				(24,327	)
Prepaid expenses and other assets		669			(101,473	)		101,474				670
Asset retirement obligations		(63,150	)		—			—				(63,150	)
Accounts payable,  accrued liabilities and other		136,449			(1,752	)		(101,474	)			33,223
Net cash provided by operating activities		308,942			42,547			—				351,489
Investing activities:
Investment in oil and natural gas properties and equipment		(269,825	)		(42,547	)		—				(312,372	)
Proceeds from sales of oil and gas properties and equipment		30,453			—			—				30,453
Change in restricted cash		(24,026	)		—			—				(24,026	)
Deposit for acquisition		(22,800	)		—			—				(22,800	)
Purchases of furniture, fixtures and other		(2,125	)		—			—				(2,125	)
Net cash used in investing activities		(288,323	)		(42,547	)		—				(330,870	)
Financing activities:
Borrowings of long-term debt – revolving bank credit facility		316,000			—			—				316,000
Repayments of long-term debt – revolving bank credit facility		(314,000	)		—			—				(314,000	)
Debt issuance costs		(2,081	)		—			—				(2,081	)
Dividends to shareholders		(17,848	)		—			—				(17,848	)
Other		(209	)		—			—				(209	)
Net cash used in financing activities		(18,138	)		—			—				(18,138	)
Increase in cash and cash equivalents		2,481			—			—				2,481
Cash and cash equivalents, beginning of period		4,512			—			—				4,512
Cash and cash equivalents, end of period	$	6,993			—			—			$	6,993
24

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2013
Operations	'
	Operations.  W&T Offshore, Inc. and subsidiaries, referred to herein as “W&T” or the “Company,” is an independent oil and natural gas producer focused primarily in the Gulf of Mexico and onshore Texas.  The Company is active in the exploration, development and acquisition of oil and natural gas properties.
Interim Financial Statements	'
	Interim Financial Statements.  The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim periods and the appropriate rules and regulations of the Securities and Exchange Commission (“SEC”).  Accordingly, the condensed consolidated financial statements do not include all of the information and footnote disclosures required by GAAP for complete financial statements for annual periods.  In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included.
	Operating results for interim periods are not necessarily indicative of the results that may be expected for the entire year.  These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.
Reclassifications	'
	Reclassifications.  Certain reclassifications have been made to the prior periods’ financial statements to conform to the current presentation.  Deferred income taxes – current asset was combined with Prepaid expenses and other assets on the Balance Sheet, Income taxes payable was combined with Accrued liabilities on the Balance Sheet, and changes in Other liabilities was combined with the changes in Accounts payable and accrued liabilities on the Statement of Cash Flows.
Use of Estimates	'
	Use of Estimates.  The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods.  Actual results could differ from those estimates.
Recent Accounting Developments	'
	Recent Accounting Developments.  In December 2011, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2011-11, Balance Sheet (Topic 210): Disclosures about Offsetting Assets and Liabilities which applies to certain items in the statement of financial position (balance sheet), and was further clarified in January 2013 by ASU 2013-01, Balance Sheet (Topic 210): Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities, which clarified the scope of ASU 2011-11 to derivative instruments, repurchase agreements and securities lending transactions.  The effective date for the amendments is for annual periods beginning after January 1, 2013, and interim periods within those annual periods.  ASU 2011-11 requires disclosures of the gross and net amounts for items eligible for offset in the balance sheet.  The Company’s derivative financial instruments are subject to master netting agreements and the Company records its derivative financial instruments on a gross basis by contract; therefore, the revisions relate to disclosure of the Company’s derivative financial instruments on a net basis.  Other items of the ASUs were not applicable to the Company.
	In February 2013, the FASB issued ASU 2013-04, Liabilities (Topic 405): Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation is Fixed at the Reporting Date, which requires an entity that is joint and severally liable to measure the obligation as the sum of the amount the entity has agreed with co-obligors to pay and any additional amount it expects to pay on behalf of one or more co-obligors.  Required disclosures include a description of the nature of the arrangement, how the liability arose, the relationship with co-obligors and the terms and conditions of the arrangement.  The effective date for the amendment is for annual periods beginning after December 15, 2013, and interim periods within those annual periods.  The amendment is to be applied retrospectively to all prior periods presented.  The Company is currently assessing the impact of ASU 2013-04 to determine the effects on the balance sheet and disclosures, if any.
	In July 2013, the FASB issued ASU 2013-11, Income Taxes (Topic 740); Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a similar Tax Loss, or a Tax Credit Carryforward Exists a consensus of the FASB Emerging Task Force, which provided guidance on the presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists.  This guidance requires an entity to present an unrecognized tax benefit as a liability in the financial statements if (i) a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date under the tax law of the applicable jurisdiction to settle any additional income taxes that would result from the disallowance of a tax position, or (ii) the tax law of the applicable jurisdiction does not require the entity to use, and the entity does not intend to use, the deferred tax asset to settle any additional income taxes that would result from the disallowance of a tax position. Otherwise, an unrecognized tax benefit is required to be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward.  Previously, there was diversity in practice as no explicit guidance existed. The amendment is effective for annual periods and interim periods beginning after December 15, 2013.  Early adoption is permitted and the amendment is to be applied prospectively.  The Company is currently assessing the impact of ASU 2013-11 to determine the effects on the balance sheet and disclosures, if any.
Other Income	'
	Other income.  For the three and nine months ended September 30, 2013, the amounts reported consisted primarily of $9.2 million received in conjunction with a payment to W&T for an option exercised by a counterparty.  Partially offsetting the proceeds were related third-party expenses of $0.1 million.

Acquisitions_and_Divestitures_

Acquisitions and Divestitures (Tables) (Newfield Properties)	9 Months Ended
	Sep. 30, 2013
Newfield Properties	'
Purchase Price Allocation for Acquisition	'
	The following table presents the purchase price allocation, including adjustments, for the acquisition of the Newfield Properties (in thousands):
	Oil and natural gas properties and equipment	$		237,396
	Asset retirement obligations – current			(7,250	)
	Asset retirement obligations – non-current			(24,414	)
	Total cash paid	$		205,732
Summary of Proforma Financial Information for Acquisition	'
	The following table presents a summary of our pro forma financial information (in thousands except earnings per share):
		Three Months Ended				Nine Months Ended
		30-Sep-12				30-Sep-12
	Revenues	$		217,714		$	741,808
	Net income			508			59,897
	Basic and diluted earnings per common share			0.01			0.79
Business Acquisition Pro Forma Information Incremental Items	'
	The following table presents incremental items included in the pro forma information reported above for the Newfield Properties (in thousands):
		Three Months Ended				Nine Months Ended
		30-Sep-12				30-Sep-12
	Revenues (a)	$		31,768		$	104,463
	Direct operating expenses (a)			9,026			33,089
	Insurance and acquisition costs, net (b)			128			444
	DD&A (c)			15,757			52,634
	Interest expense (d)			3,960			11,881
	Capitalized interest (e)			148			634
	Income tax expense (f)			1,066			2,467
		The sources of information and significant assumptions are described below:
		(a)	Revenues and direct operating expenses for the Newfield Properties were derived from the historical financial records of Newfield.
		(b)	Incremental costs for insurance were estimated using the incremental costs to add the Newfield Properties to W&T’s insurance programs.  The direct operating expenses for the Newfield Properties described above exclude insurance costs.  Expenses were reduced for acquisition costs incurred.
		(c)	DD&A was estimated using the full-cost method and determined as the incremental DD&A expense due to adding the Newfield Properties’ costs, reserves and production into our currently existing full cost pool in order to compute such amounts.  The purchase price allocation included $13.1 million that was allocated to the pool of unevaluated properties for oil and natural gas interests.  Accordingly, no DD&A expense was estimated for the unevaluated properties.  ARO was estimated by W&T management.
		(d)	The acquisition was assumed to be funded entirely with borrowed funds.  Interest expense was computed using assumed borrowings of $205.7 million, which equates to the cash paid including purchase price adjustments and an interest rate of 7.7%, which equates to the effective yield on net proceeds for the additional senior notes issued shortly after the acquisition closed.
		(e)	Incremental capitalized interest was computed for the addition to the pool of unevaluated properties and the capitalization interest rate was adjusted for the assumed borrowings.
		(f)	Income tax expense was computed using the 35% federal statutory rate.

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	9 Months Ended
	Sep. 30, 2013
Reconciliation of Asset Retirement Obligations Liability	'
	A summary of the changes to our ARO is as follows (in thousands):
	Balance, December 31, 2012	$	384,053
	Liabilities settled		(59,188	)
	Accretion of discount		16,236
	Disposition of properties		(19,564	)
	Liabilities incurred		372
	Revisions of estimated liabilities due to Hurricane Ike (1)		5,526
	Revisions of estimated liabilities – all other (1)		34,672
	Balance, September 30, 2013		362,107
	Less current portion		95,014
	Long-term	$	267,093
		(1) Revisions are primarily due to increases in the scope of work at several offshore locations required by the Bureau of Safety and Environmental Enforcement (“BSEE”).

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Open Commodity Derivatives	'
	As of September 30, 2013, our open commodity derivative contracts were as follows:
			Swaps – Oil
			Priced off Brent (ICE)						Priced off WTI (NYMEX)
	Termination Period		Notional		Weighted				Notional	Weighted
			Quantity (Bbls)		Average				Quantity (Bbls)	Average
					Contract Price					Contract Price
	2013:00:00	4th quarter	294,400		$		101.98		520,000	$	97.38
	2014:00:00	1st quarter	180,000				97.38		762,000		97.39
		2nd quarter	172,900				97.38		455,000		97.17
		3rd quarter	165,600				97.38		155,000		97.00
		4th quarter	156,400				97.37		—		—
			969,300		$		98.77		1,892,000	$	97.30
Estimated Fair Value of Derivative Contracts	'
	The following balance sheet line items included amounts related to the estimated fair value of our open derivative contracts as indicated in the following table (in thousands):
		September 30,			December 31,
		2013			2012
	Prepaid and other assets	$	317		$		—
	Accrued liabilities		8,611				6,355
	Other liabilities (noncurrent)		439				3,046
Changes in Fair Value of Commodity Derivative Contracts Recognized in Earnings	'
	Changes in the fair value of our commodity derivative contracts are recognized currently in earnings and were as follows (in thousands):
		Three Months Ended								Nine Months Ended
		September 30,								September 30,
		2013				2012				2013			2012
	Derivative (gain) loss:
	Realized	$	4,545			$		875		$	6,855			$	6,960
	Unrealized		11,114					23,784			(669	)			7,461
	Total	$	15,659			$		24,659		$	6,186			$	14,421
Reconciliation of Gross Assets and Liabilities and Netting Agreements on Fair Value of Open Derivative Contracts	'
	The following table presents disclosures required by ASU 2011-11 and ASU 2013-01 and provides a reconciliation of the gross assets and liabilities reflected in the balance sheet and the potential effects of master netting agreements on the fair value of open derivative contracts as of September 30, 2013 (in thousands):
			Derivative					Derivative
			Assets					Liabilities
	Gross amounts presented in the balance sheet	$	317			$		9,050
	Amounts not offset in the balance sheet		(317	)				(317	)
	Net amounts	$	—			$		8,733

LongTerm_Debt_Tables

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Long-Term Debt	'
	Our long-term debt was as follows (in thousands):
		September 30,		December 31,
		2013		2012
	8.50% Senior Notes	$	900,000	$	900,000
	Debt premiums, net of amortization		15,984		17,611
	Revolving bank credit facility		137,000		170,000
	Total long-term debt		1,052,984		1,087,611
	Current maturities of long-term debt		—		—
	Long-term debt, less current maturities	$	1,052,984	$	1,087,611

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Fair Value of Derivatives Financial Instruments and Long-Term Senior Notes	'
	The following table presents the fair value of our derivative financial instruments, 8.50% Senior Notes and revolving bank credit facility for the periods indicated (in thousands).
			September 30, 2013					December 31, 2012
		Hierarchy	Assets		Liabilities				Assets			Liabilities
	Derivatives	Level 2	$	317		$	9,050			$	—		$	9,401
	8.50% Senior Notes	Level 2		—			977,625				—			963,000
	Revolving bank credit facility	Level 2		—			137,000				—			170,000

ShareBased_Compensation_and_Ca1

Share-Based Compensation and Cash-Based Incentive Compensation (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	'
	A summary of activity in 2013 related to restricted stock is as follows:
		Restricted Stock
		Shares		Weighted
				Average
				Grant Date
				Fair Value
				Per Share
	Outstanding restricted shares, December 31, 2012	43,687		$	18.69
	Granted	27,450			12.75
	Vested	(27,297	)		17.09
	Outstanding restricted shares, September 30, 2013	43,840		$	15.96
Schedule of Restricted Stock Awards Outstanding	'
	Subject to the satisfaction of service conditions, the outstanding restricted shares issued to the non-employee directors as of September 30, 2013 are expected to vest as follows:
		Shares
	2014	19,445
	2015	15,245
	2016	9,150
	Total	43,840
Summary of Share Activity Related to Restricted Stock Units	'
	A summary of activity in 2013 related to RSUs is as follows:
		Restricted Stock Units
		Units		Weighted
				Average
				Grant Date
				Fair Value
				Per Unit
	Outstanding RSUs, December 31, 2012	969,820		$	22.70
	Granted	969,919			13.23
	Forfeited	(33,042	)		18.86
	Outstanding RSUs, September 30, 2013	1,906,697		$	17.95
Schedule of Restricted Stock Awards Outstanding	'
	Subject to the satisfaction of service conditions, the RSUs outstanding as of September 30, 2013 are eligible to vest in the year indicated in the table below:
		Units
	2013 – subject to service requirements	470,536
	2014 – subject to service requirements	335,555
	2014 – subject to service and other requirements (1)	138,330
	2015 – subject to service requirements	23,500
	2015 – subject to service and other requirements  (2)	657,143
	2015 – subject to service and other requirements  (3)	281,633
	Total	1,906,697
	(1	)		In addition to service requirements, these RSUs are also subject to TSR performance requirements not yet measureable, with awards ranging from 0% to 150% of amounts granted.
	(2	)		In addition to service requirements, these RSUs are also subject to certain Company-specific performance requirements not yet measureable, with awards ranging from 0% to 150% of amounts granted.
	(3	)		In addition to service requirements, these RSUs are also subject to TSR performance requirements not yet measureable, with awards ranging from 0% to 200% of amounts granted.
Summary of Compensation Expense under Share-Based Payment Arrangements and Related Tax Benefit	'
	A summary of incentive compensation expense under share-based payment arrangements and the related tax benefit is as follows (in thousands):
		Three Months Ended								Nine Months Ended
		September 30,								September 30,
		2013				2012				2013					2012
	Share-based compensation expense from:
	Restricted stock	$		99		$	110		$			297		$		324
	Restricted stock units			3,408			3,209					8,160				8,813
	Total	$		3,507		$	3,319		$			8,457		$		9,137
	Share-based compensation tax benefit:
	Tax benefit computed at the statutory rate	$		1,227		$	1,162		$			2,960		$		3,198
Summary of Incentive Compensation Expense	'
	A summary of incentive compensation expense is as follows (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013				2012		2013			2012
	Share-based compensation expense included in:
	General and administrative - charge to operating income	$		3,507		$	3,319	$	8,457		$		9,137
	Cash-based incentive compensation included in:
	Lease operating expense			724			947		2,864				2,846
	General and administrative			2,191			3,048		7,745				4,926
	Total charged to operating income			2,915			3,995		10,609				7,772
	Total incentive compensation charged to operating income	$		6,422		$	7,314	$	19,066		$		16,909

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Calculation of Basic and Diluted Earnings Per Common Share	'
	The following table presents the calculation of basic and diluted earnings per common share (in thousands, except per share amounts):
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
		2013		2012			2013		2012
	Net income (loss)	$	14,194	$	(1,471	)	$	63,208	$	55,315
	Less portion allocated to nonvested shares		159		90			713		1,128
	Net income (loss) allocated to common shares	$	14,035	$	(1,561	)	$	62,495	$	54,187
	Weighted average common shares outstanding		75,233		74,327			75,221		74,315
	Basic and diluted earnings (loss) per common share	$	0.19	$	(0.02	)	$	0.83	$	0.73
	Shares excluded due to being anti-dilutive (weighted-average)		851		1,866			860		1,823

Subsequent_Events_Tables

Subsequent Events (Tables) (Callon Properties, Subsequent Event)	9 Months Ended
	Sep. 30, 2013
Callon Properties | Subsequent Event	'
Purchase Price Allocation for Acquisition	'
	The following table presents the preliminary purchase price allocation, including estimated adjustments, for the acquisition of the Callon Properties including in the First Closing (in thousands):
	Oil and natural gas properties and equipment	$	79,136
	Asset retirement obligations – current		(15	)
	Asset retirement obligations – non-current		(2,713	)
	Total cash paid	$	76,408
Summary of Proforma Financial Information for Acquisition	'
	The following table presents a summary of our pro forma financial information (in thousands except earnings per share):
		Three Months Ended								Nine Months Ended
		September 30,								September 30,
			2013			2012						2013			2012
	Revenues	$	254,092		$	197,076		$				766,801		$	670,881
	Net income		16,513			858						69,310			63,801
	Basic and diluted earnings per common share		0.22			0.01						0.91			0.84
Business Acquisition Pro Forma Information Incremental Items	'
	The following table presents incremental items included in the pro forma information reported above for the Callon Properties included in the First Closing (in thousands):
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
			2013			2012		2013					2012
	Revenues (a)	$	9,537		$	11,130	$	27,641			$		33,536
	Direct operating expenses (a)		1,459			1,614		4,915					4,628
	Insurance costs (b)		510			510		1,531					1,214
	DD&A (c)		3,615			4,822		10,735					13,095
	Interest expense (d)		382			382		1,146					1,146
	Capitalized interest (e)		4			219		(74	)				398
	Income tax expense (f)		1,248			1,254		3,286					4,569
	The sources of information and significant assumptions are described below:
	(a)              Revenues and direct operating expenses for the Callon Properties were derived from the unaudited historical financial records of Callon.
	(b)              Incremental costs for insurance were estimated from the incremental costs to add the Callon Properties included in the First Close to W&T’s insurance programs.  The direct operating expenses for the Callon Properties described above exclude insurance costs.
	(c)              DD&A was estimated using the full-cost method and determined as the incremental DD&A expense due to adding the Callon Properties’ costs, reserves and production into our currently existing full cost pool in order to compute such amounts.  The purchase price allocation included $7.2 million that was allocated to the pool of unevaluated properties for oil and natural gas interests.  Accordingly, no DD&A expense was estimated for the unevaluated properties.  ARO was estimated by W&T management.
	(d)              The acquisition was assumed to be funded entirely with borrowed funds.  Interest expense was computed using assumed borrowings of $76.4 million, which equates to the cash component of the transaction, and an interest rate of 2.0%, which equates to the rates applied to incremental borrowings on the revolving bank credit facility.
	(e)              The change to capitalized interest was computed for the addition to the pool of unevaluated properties and the capitalization interest rate was adjusted for the assumed borrowings.  Positive amounts represent increases to net expenses.  The negative amount represents a decrease to net expenses.
	(f)              Income tax expense was computed using the 35% federal statutory rate.
	(g)              The 2012 periods above do not include any pro forma adjustments related to the 2012 acquisition as described in Note 2.

Supplemental_Guarantor_Informa1

Supplemental Guarantor Information (Tables)	9 Months Ended
	Sep. 30, 2013
Condensed Consolidating Balance Sheet	'
	Condensed Consolidating Balance Sheet as of September 30, 2013
		Parent				Guarantor				Eliminations							Consolidated
		Company				Subsidiaries											W&T
																	Offshore, Inc.
		(In thousands)
	Assets
	Current assets:
	Cash and cash equivalents	$	15,227			$		—		$		—						$		15,227
	Receivables:
	Oil and natural gas sales		66,953					18,301				(33		)						85,221
	Joint interest and other		31,492					—				—								31,492
	Total receivables		98,445					18,301				(33		)						116,713
	Restricted cash and cash equivalents		16,459					—				—								16,459
	Prepaid expenses and other assets		152,739					3,991				(123,880		)						32,850
	Total current assets		282,870					22,292				(123,913		)						181,249
	Property and equipment – at cost:
	Oil and natural gas properties and equipment		6,703,175					416,911				—								7,120,086
	Furniture, fixtures and other		21,325					—				—								21,325
	Total property and equipment		6,724,500					416,911				—								7,141,411
	Less accumulated depreciation, depletion and amortization		4,690,550					260,218				—								4,950,768
	Net property and equipment		2,033,950					156,693				—								2,190,643
	Restricted deposits for asset retirement obligations		34,966					—				—								34,966
	Deferred income taxes		—					4,549				(4,549		)						—
	Other assets		481,029					441,908				(906,095		)						16,842
	Total assets	$	2,832,815			$		625,442		$		(1,034,557		)				$		2,423,700
	Liabilities and Shareholders’ Equity
	Current liabilities:
	Accounts payable	$	130,021			$		—		$		(33		)				$		129,988
	Undistributed oil and natural gas proceeds		40,989					289				—								41,278
	Asset retirement obligations		95,014					—				—								95,014
	Accrued liabilities		45,272					129,656				(123,880		)						51,048
	Total current liabilities		311,296					129,945				(123,913		)						317,328
	Long-term debt		1,052,984					—				—								1,052,984
	Asset retirement obligations, less current portion		235,782					31,311				—								267,093
	Deferred income taxes		181,953					—				(4,549		)						177,404
	Other liabilities		457,768					—				(441,909		)						15,859
	Shareholders’ equity:
	Common stock		1					—				—								1
	Additional paid-in capital		404,604					231,759				(231,759		)						404,604
	Retained earnings		212,594					232,427				(232,427		)						212,594
	Treasury stock, at cost		(24,167	)				—				—								(24,167	)
	Total shareholders’ equity		593,032					464,186				(464,186		)						593,032
	Total liabilities and shareholders’ equity	$	2,832,815			$		625,442		$		(1,034,557		)				$		2,423,700
	Condensed Consolidating Balance Sheet as of December 31, 2012
		Parent				Guarantor				Eliminations					Consolidated
		Company				Subsidiaries									W&T
															Offshore, Inc.
		(In thousands)
	Assets
	Current assets:
	Cash and cash equivalents	$	12,245			$		—		$		—			$		12,245
	Receivables:
	Oil and natural gas sales		80,729					17,004				—					97,733
	Joint interest and other		56,439					—				—					56,439
	Income taxes		163,750					—				(115,866	)				47,884
	Total receivables		300,918					17,004				(115,866	)				202,056
	Prepaid expenses and other assets		25,822					—				—					25,822
	Total current assets		338,985					17,004				(115,866	)				240,123
	Property and equipment – at cost:
	Oil and natural gas properties and equipment		6,356,529					337,981				—					6,694,510
	Furniture, fixtures and other		21,786					—				—					21,786
	Total property and equipment		6,378,315					337,981				—					6,716,296
	Less accumulated depreciation, depletion and amortization		4,461,886					193,955				—					4,655,841
Net property and equipment		1,916,429					144,026				—					2,060,455
Restricted deposits for asset retirement obligations		28,466					—				—					28,466
Deferred income taxes		—					13,509				(13,509	)				—
Other assets		442,540					393,499				(816,096	)				19,943
Total assets	$	2,726,420			$		568,038		$		(945,471	)		$		2,348,987
Liabilities and Shareholders’ Equity
Current liabilities:
Accounts payable	$	123,792			$		93		$		—			$		123,885
Undistributed oil and natural gas proceeds		36,791					282				—					37,073
Asset retirement obligations		92,595					—				35					92,630
Accrued liabilities		20,755					116,132				(115,866	)				21,021
Total current liabilities		273,933					116,507				(115,831	)				274,609
Long-term debt		1,087,611					—				—					1,087,611
Asset retirement obligations, less current portion		262,524					28,934				(35	)				291,423
Deferred income taxes		158,758					—				(13,509	)				145,249
Other liabilities		402,407					—				(393,499	)				8,908
Shareholders’ equity:
Common stock		1					—				—					1
Additional paid-in capital		396,186					231,759				(231,759	)				396,186
Retained earnings		169,167					190,838				(190,838	)				169,167
Treasury stock, at cost		(24,167	)				—				—					(24,167		)
Total shareholders’ equity		541,187					422,597				(422,597	)				541,187
Total liabilities and shareholders’ equity	$	2,726,420			$		568,038		$		(945,471	)		$		2,348,987
Condensed Consolidating Statement of Income	'
	Condensed Consolidating Statement of Income for the Three Months Ended September 30, 2013
		Parent						Guarantor							Eliminations						Consolidated
		Company						Subsidiaries													W&T
																					Offshore, Inc.
		(In thousands)
	Revenues	$	195,064						$	49,491						$		—				$	244,555
	Operating costs and expenses:
	Lease operating expenses		64,952							2,394								—					67,346
	Production taxes		1,807							—								—					1,807
	Gathering and transportation		2,706							905								—					3,611
	Depreciation, depletion, amortization and accretion		80,230							23,913								—					104,143
	General and administrative expenses		19,375							649								—					20,024
	Derivative loss		15,659							—								—					15,659
	Total costs and expenses		184,729							27,861								—					212,590
	Operating income		10,335							21,630								—					31,965
	Earnings of affiliates		14,032							—								(14,032		)			—
	Interest expense:
	Incurred		21,373							—								—					21,373
	Capitalized		(2,573		)					—								—					(2,573	)
	Other income		9,062							—								—					9,062
	Income before income tax expense		14,629							21,630								(14,032		)			22,227
	Income tax expense		435							7,598								—					8,033
	Net income	$	14,194						$	14,032						$		(14,032		)		$	14,194
	Condensed Consolidating Statement of Income for the Nine Months Ended September 30, 2013
		Parent				Guarantor				Eliminations					Consolidated
		Company				Subsidiaries									W&T
															Offshore, Inc.
		(In thousands)
	Revenues	$	590,492			$		148,668		$		—			$		739,160
	Operating costs and expenses:
	Lease operating expenses		184,458					10,477				—					194,935
	Production taxes		5,375					—				—					5,375
	Gathering and transportation		10,099					2,564				—					12,663
	Depreciation, depletion, amortization and accretion		244,597					68,314				—					312,911
	General and administrative expenses		57,738					3,241				—					60,979
	Derivative loss		6,186					—				—					6,186
	Total costs and expenses		508,453					84,596				—					593,049
	Operating income		82,039					64,072				—					146,111
	Earnings of affiliates		41,589					—				(41,589	)				—
	Interest expense:
	Incurred		64,157					—				—					64,157
	Capitalized		(7,537	)				—				—					(7,537		)
	Other income		9,075					—				—					9,075
	Income before income tax expense		76,083					64,072				(41,589	)				98,566
	Income tax expense		12,875					22,483				—					35,358
	Net income	$	63,208			$		41,589		$		(41,589	)		$		63,208
	Condensed Consolidating Statement of Income for the Three Months Ended September 30, 2012
		Parent				Guarantor				Eliminations					Consolidated
		Company				Subsidiaries									W&T
															Offshore, Inc.
		(In thousands)
	Revenues	$	141,139			$		44,807		$		—			$				185,946
	Operating costs and expenses:
	Lease operating expenses		47,353					6,058				—							53,411
	Production taxes		1,353					—				—							1,353
	Gathering and transportation		2,084					726				—							2,810
	Depreciation, depletion, amortization and accretion		58,744					18,718				—							77,462
	General and administrative expenses		18,691					—				—							18,691
	Derivative loss		24,659					—				—							24,659
	Total costs and expenses		152,884					25,502				—							178,386
	Operating income (loss)		(11,745	)				19,305				—							7,560
	Earnings of affiliates		12,551					—				(12,551	)						—
	Interest expense:
Incurred		14,791					—				—							14,791
Capitalized		(3,383	)				—				—							(3,383	)
Other income		202					—				—							202
Income (loss) before income tax expense		(10,400	)				19,305				(12,551	)						(3,646	)
Income tax expense (benefit)		(8,929	)				6,754				—							(2,175	)
Net income (loss)	$	(1,471	)		$		12,551		$		(12,551	)		$				(1,471	)
Condensed Consolidating Statement of Income for the Nine Months Ended September 30, 2012
	Parent				Guarantor				Eliminations					Consolidated
	Company				Subsidiaries									W&T
														Offshore, Inc.
	(In thousands)
Revenues	$	473,297			$		164,048		$		—			$		637,345
Operating costs and expenses:
Lease operating expenses		150,860					19,489				—					170,349
Production taxes		4,174					—				—					4,174
Gathering and transportation		8,788					2,352				—					11,140
Depreciation, depletion, amortization and accretion		189,827					62,067				—					251,894
General and administrative expenses		60,200					2,593				—					62,793
Derivative loss		14,421					—				—					14,421
Total costs and expenses		428,270					86,501				—					514,771
Operating income		45,027					77,547				—					122,574
Earnings of affiliates		50,395					—				(50,395	)				—
Interest expense:
Incurred		43,409					—				—					43,409
Capitalized		(9,899	)				—				—					(9,899		)
Other income		210					—				—					210
Income before income tax expense		62,122					77,547				(50,395	)				89,274
Income tax expense		6,807					27,152				—					33,959
Net income	$	55,315			$		50,395		$		(50,395	)		$		55,315
Condensed Consolidating Statement of Cash Flows	'
	Condensed Consolidating Statement of Cash Flows for the Nine Months Ended September 30, 2013
		Parent				Guarantor				Eliminations					Consolidated
		Company				Subsidiaries									W&T
															Offshore, Inc.
		(In thousands)
	Operating activities:
	Net income	$	63,208			$		41,589		$		(41,589	)		$		63,208
	Adjustments to reconcile net income to net cash provided by operating activities:
	Depreciation, depletion, amortization and accretion		244,597					68,314				—					312,911
	Amortization of debt issuance costs and premium		1,366					—				—					1,366
	Share-based compensation		8,457					—				—					8,457
	Derivative loss		6,186					—				—					6,186
	Cash payments on derivative settlements		(6,855	)				—				—					(6,855	)
	Deferred income taxes		22,621					8,960				—					31,581
	Earnings of affiliates		(41,589	)				—				41,589					—
	Changes in operating assets and liabilities:
	Oil and natural gas receivables		13,775					(1,264	)			—					12,511
	Joint interest and other receivables		24,947					—				—					24,947
	Insurance receivables		5,117					—				—					5,117
	Income taxes		39,909					13,524				—					53,433
	Prepaid expenses and other assets		(6,823	)				(52,400	)			48,408					(10,815	)
	Asset retirement obligation settlements		(59,017	)				(171	)			—					(59,188	)
	Accounts payable, accrued liabilities and other		81,501					(119	)			(48,408	)				32,974
	Net cash provided by operating activities		397,400					78,433				—					475,833
	Investing activities:
	Investment in oil and natural gas properties and equipment		(344,659	)				(78,433	)			—					(423,092	)
	Proceeds from sales of assets and other, net		21,011					—				—					21,011
	Change in restricted cash		(16,459	)				—				—					(16,459	)
	Purchases of furniture, fixtures and other		(1,327	)				—				—					(1,327	)
	Net cash used in investing activities		(341,434	)				(78,433	)			—					(419,867	)
	Financing activities:
	Borrowings of long-term debt – revolving bank credit facility		335,000					—				—					335,000
	Repayments of long-term debt – revolving bank credit facility		(368,000	)				—				—					(368,000	)
	Debt issuance costs		(164	)				—				—					(164	)
	Dividends to shareholders		(19,570	)				—				—					(19,570	)
	Other		(250	)				—				—					(250	)
	Net cash used in financing activities		(52,984	)				—				—					(52,984	)
	Increase in cash and cash equivalents		2,982					—				—					2,982
	Cash and cash equivalents, beginning of period		12,245					—				—					12,245
	Cash and cash equivalents, end of period	$	15,227			$		—		$		—			$		15,227
	Condensed Consolidating Statement of Cash Flows for the Nine Months Ended September 30, 2012
		Parent					Guarantor			Eliminations					Consolidated
		Company					Subsidiaries								W&T
															Offshore, Inc.
		(In thousands)
	Operating activities:
	Net income	$	55,315				50,395			(50,395	)		$		55,315
	Adjustments to reconcile net income to net cash provided by operating activities:
	Depreciation, depletion, amortization and accretion		189,827				62,067			—					251,894
	Amortization of debt issuance costs		2,046				—			—					2,046
	Share-based compensation		9,137				—			—					9,137
	Derivative loss		14,421				—			—					14,421
	Cash payments on derivative settlements		(6,960	)			—			—					(6,960		)
	Deferred income taxes		42,816				1,649			—					44,465
	Earnings of affiliates		(50,395	)			—			50,395					—
	Changes in operating assets and liabilities:
	Oil and natural gas receivables		24,162				6,158			—					30,320
	Joint interest and other receivables		3,935				—			—					3,935
	Insurance receivables		500				—			—					500
	Income taxes		(49,830	)			25,503			—					(24,327		)
	Prepaid expenses and other assets		669				(101,473	)		101,474					670
	Asset retirement obligations		(63,150	)			—			—					(63,150		)
	Accounts payable,  accrued liabilities and other		136,449				(1,752	)		(101,474	)				33,223
Net cash provided by operating activities		308,942				42,547			—					351,489
Investing activities:
Investment in oil and natural gas properties and equipment		(269,825	)			(42,547	)		—					(312,372		)
Proceeds from sales of oil and gas properties and equipment		30,453				—			—					30,453
Change in restricted cash		(24,026	)			—			—					(24,026		)
Deposit for acquisition		(22,800	)			—			—					(22,800		)
Purchases of furniture, fixtures and other		(2,125	)			—			—					(2,125		)
Net cash used in investing activities		(288,323	)			(42,547	)		—					(330,870		)
Financing activities:
Borrowings of long-term debt – revolving bank credit facility		316,000				—			—					316,000
Repayments of long-term debt – revolving bank credit facility		(314,000	)			—			—					(314,000		)
Debt issuance costs		(2,081	)			—			—					(2,081		)
Dividends to shareholders		(17,848	)			—			—					(17,848		)
Other		(209	)			—			—					(209		)
Net cash used in financing activities		(18,138	)			—			—					(18,138		)
Increase in cash and cash equivalents		2,481				—			—					2,481
Cash and cash equivalents, beginning of period		4,512				—			—					4,512
Cash and cash equivalents, end of period	$	6,993				—			—			$		6,993

Basis_of_Presentation_Addition

Basis of Presentation - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013
Basis Of Presentation [Line Items]	'	'
Payments received related to break-up fee and termination of certain purchase and sale agreement	$9.20	$9.20
Third-party expenses related to the cancelled transaction	$0.10	$0.10

Purchase_Price_Allocation_for_

Purchase Price Allocation for Acquisition of Newfield Properties (Detail) (Newfield Properties, USD $)	1 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Oct. 05, 2012	Sep. 30, 2013
Newfield Properties	'	'
Business Acquisition [Line Items]	'	'
Oil and natural gas properties and equipment	'	$237,396
Asset retirement obligations – current	'	-7,250
Asset retirement obligations – non-current	'	-24,414
Total cash paid	$205,732	$205,732

Summary_of_Proforma_Financial_

Summary of Proforma Financial Information for Acquisition of Newfield Properties (Detail) (Newfield Properties, USD $)	3 Months Ended	9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2012
Newfield Properties	'	'
Business Acquisition [Line Items]	'	'
Revenues	$217,714	$741,808
Net income	$508	$59,897
Basic and diluted earnings per common share	$0.01	$0.79

Business_Acquisition_Pro_Forma

Business Acquisition Pro Forma Information Incremental Items, Newfield Properties (Detail) (USD $)	3 Months Ended			9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013	Sep. 30, 2012
Business Acquisition [Line Items]	'	'		'	'
Revenues	$244,555	$185,946		$739,160	$637,345
Direct operating expenses	67,346	53,411		194,935	170,349
DD&A	104,143	77,462		312,911	251,894
Interest expense	21,373	14,791		64,157	43,409
Capitalized interest	2,573	3,383		7,537	9,899
Income tax expense (benefit)	8,033	-2,175		35,358	33,959
Newfield Properties | Pro Forma	'	'		'	'
Business Acquisition [Line Items]	'	'		'	'
Revenues	'	31,768	[1]	'	104,463	[1]
Direct operating expenses	'	9,026	[1]	'	33,089	[1]
Insurance and acquisition costs, net	'	128	[2]	'	444	[2]
DD&A	'	15,757	[3]	'	52,634	[3]
Interest expense	'	3,960	[4]	'	11,881	[4]
Capitalized interest	'	148	[5]	'	634	[5]
Income tax expense (benefit)	'	$1,066	[6]	'	$2,467	[6]
[1]	Revenues and direct operating expenses for the Newfield Properties were derived from the historical financial records of Newfield.
[2]	Incremental costs for insurance were estimated using the incremental costs to add the Newfield Properties to W&T’s insurance programs. The direct operating expenses for the Newfield Properties described above exclude insurance costs. Expenses were reduced for acquisition costs incurred.
[3]	DD&A was estimated using the full-cost method and determined as the incremental DD&A expense due to adding the Newfield Properties’ costs, reserves and production into our currently existing full cost pool in order to compute such amounts. The purchase price allocation included $13.1 million that was allocated to the pool of unevaluated properties for oil and natural gas interests. Accordingly, no DD&A expense was estimated for the unevaluated properties. ARO was estimated by W&T management.
[4]	The acquisition was assumed to be funded entirely with borrowed funds. Interest expense was computed using assumed borrowings of $205.7 million, which equates to the cash paid including purchase price adjustments and an interest rate of 7.7%, which equates to the effective yield on net proceeds for the additional senior notes issued shortly after the acquisition closed.
[5]	Incremental capitalized interest was computed for the addition to the pool of unevaluated properties and the capitalization interest rate was adjusted for the assumed borrowings.
[6]	Income tax expense was computed using the 35% federal statutory rate.

Acquisitions_and_Divestitures_1

Acquisitions and Divestitures - Additional Information (Detail) (USD $)

0 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

Jul. 11, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Oct. 05, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2012

15-May-12

Sep. 26, 2013

Newfield Properties

Newfield Properties

Newfield Properties Post Acquisition

Newfield Properties Post Acquisition

Newfield Properties Post Acquisition

Newfield Properties Post Acquisition

South Timbalier 41

West Delta Area Block Twenty Nine

acre

Maximum

Maximum

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Oil and natural gas properties and equipment - full cost method, amount excluded from amortization

'

$129,584,000

'

$129,584,000

'

$123,503,000

'

$13,100,000

'

'

'

'

'

'

Long-term debt

'

1,052,984,000

'

1,052,984,000

'

1,087,611,000

'

205,700,000

'

'

'

'

'

'

Effective interest rate

'

'

'

'

'

'

'

7.70%

'

'

'

'

'

'

Total cash paid for acquisition

'

'

'

'

'

'

-205,732,000

-205,732,000

'

'

'

'

'

'

Number of federal offshore blocks

'

'

'

'

'

'

78

'

'

'

'

'

'

'

Leasehold interest acres acquired, gross

'

'

'

'

'

'

416,000

'

'

'

'

'

'

'

Leasehold interest acres acquired, net

'

'

'

'

'

'

268,000

'

'

'

'

'

'

'

Adjustments to purchase price

'

'

'

'

'

'

'

200,000

'

'

'

'

'

'

Revenues

'

244,555,000

185,946,000

739,160,000

637,345,000

'

'

'

31,900,000

94,200,000

'

'

'

'

Lease operating expenses

'

67,346,000

53,411,000

194,935,000

170,349,000

'

'

'

5,500,000

19,600,000

'

'

'

'

Depreciation, depletion, amortization and accretion

'

104,143,000

77,462,000

312,911,000

251,894,000

'

'

'

14,700,000

41,100,000

'

'

'

'

Income tax expense (benefit)

'

8,033,000

-2,175,000

35,358,000

33,959,000

'

'

'

4,100,000

11,700,000

'

'

'

'

Net income

'

14,194,000

-1,471,000

63,208,000

55,315,000

'

'

'

7,600,000

21,800,000

'

'

'

'

Expenses associated with acquisition activities and transition activities

'

'

'

'

'

'

'

'

'

'

100,000

100,000

'

'

Percentage of non-operating working interest sold

'

'

'

'

'

'

'

'

'

'

'

'

40.00%

'

Proceeds from sale of non-operating working interest

'

'

'

'

'

'

'

'

'

'

'

'

30,500,000

16,500,000

Reversal of asset retirement obligation

15,600,000

'

'

'

'

'

'

'

'

'

'

'

4,000,000

3,900,000

Federal statutory income tax rate

'

'

'

35.00%

'

'

'

35.00%

'

'

'

'

'

'

Adjustment for effective date to sell properties

$4,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Hurricane_Remediation_and_Insu1

Hurricane Remediation and Insurance Claims - Additional Information (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2008	Sep. 30, 2013
Business Interruption Loss [Line Items]	'	'
Retention amount per occurrence	$10	'
Maximum insurance coverage policy limit due to named windstorms for per incident	150	'
Maximum insurance coverage policy limit except for, property damage due to named windstorms	250	'
Insurance recoveries related to hurricanes	'	$147.30

Reconciliation_of_Asset_Retire

Reconciliation of Asset Retirement Obligations Liability (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'		'
Asset retirement obligations, beginning of period	$384,053		'
Liabilities settled	-59,188		'
Accretion of discount	16,236		'
Disposition of properties	-19,564		'
Liabilities incurred	372		'
Asset retirement obligations, end of period	362,107		'
Less current portion	95,014		92,630
Long-term	267,093		291,423
Hurricane Ike	'		'
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'		'
Revisions of estimated liabilities	5,526	[1]	'
All Other	'		'
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'		'
Revisions of estimated liabilities	$34,672	[1]	'
[1]	Revisions are primarily due to increases in the scope of work at several offshore locations required by the Bureau of Safety and Environmental Enforcement (“BSEE”).

Open_Commodity_Derivatives_Det

Open Commodity Derivatives (Detail) (Swaps Oil)	9 Months Ended
	Sep. 30, 2013
Ice Brent Crude Oil Futures	'
Derivatives Fair Value [Line Items]	'
Notional Quantity (Bbls)	969,300
Weighted Average Contract Price	98.77
Nymex Crude Oil Futures	'
Derivatives Fair Value [Line Items]	'
Notional Quantity (Bbls)	1,892,000
Weighted Average Contract Price	97.3
2013: 4th Quarter	'
Derivatives Fair Value [Line Items]	'
Termination Period	'4th quarter
2013: 4th Quarter | Ice Brent Crude Oil Futures	'
Derivatives Fair Value [Line Items]	'
Notional Quantity (Bbls)	294,400
Weighted Average Contract Price	101.98
2013: 4th Quarter | Nymex Crude Oil Futures	'
Derivatives Fair Value [Line Items]	'
Notional Quantity (Bbls)	520,000
Weighted Average Contract Price	97.38
2014: 1st Quarter	'
Derivatives Fair Value [Line Items]	'
Termination Period	'1st quarter
2014: 1st Quarter | Ice Brent Crude Oil Futures	'
Derivatives Fair Value [Line Items]	'
Notional Quantity (Bbls)	180,000
Weighted Average Contract Price	97.38
2014: 1st Quarter | Nymex Crude Oil Futures	'
Derivatives Fair Value [Line Items]	'
Notional Quantity (Bbls)	762,000
Weighted Average Contract Price	97.39
2014: 2nd Quarter	'
Derivatives Fair Value [Line Items]	'
Termination Period	'2nd quarter
2014: 2nd Quarter | Ice Brent Crude Oil Futures	'
Derivatives Fair Value [Line Items]	'
Notional Quantity (Bbls)	172,900
Weighted Average Contract Price	97.38
2014: 2nd Quarter | Nymex Crude Oil Futures	'
Derivatives Fair Value [Line Items]	'
Notional Quantity (Bbls)	455,000
Weighted Average Contract Price	97.17
2014: 3rd Quarter	'
Derivatives Fair Value [Line Items]	'
Termination Period	'3rd quarter
2014: 3rd Quarter | Ice Brent Crude Oil Futures	'
Derivatives Fair Value [Line Items]	'
Notional Quantity (Bbls)	165,600
Weighted Average Contract Price	97.38
2014: 3rd Quarter | Nymex Crude Oil Futures	'
Derivatives Fair Value [Line Items]	'
Notional Quantity (Bbls)	155,000
Weighted Average Contract Price	97
2014: 4th Quarter	'
Derivatives Fair Value [Line Items]	'
Termination Period	'4th quarter
2014: 4th Quarter | Ice Brent Crude Oil Futures	'
Derivatives Fair Value [Line Items]	'
Notional Quantity (Bbls)	156,400
Weighted Average Contract Price	97.37

Estimated_Fair_Value_of_Deriva

Estimated Fair Value of Derivative Contracts (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Derivatives Fair Value [Line Items]	'	'
Fair value of commodity derivative contracts	$317	'
Fair value of commodity derivative contracts	9,050	'
Prepaid And Other Assets	'	'
Derivatives Fair Value [Line Items]	'	'
Fair value of commodity derivative contracts	317	'
Accrued Liabilities	'	'
Derivatives Fair Value [Line Items]	'	'
Fair value of commodity derivative contracts	8,611	6,355
Other Liabilities (noncurrent)	'	'
Derivatives Fair Value [Line Items]	'	'
Fair value of commodity derivative contracts	$439	$3,046

Changes_in_Fair_Value_of_Commo

Changes in Fair Value of Commodity Derivative Contracts Recognized in Earnings (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative (gain) loss:	'	'	'	'
Realized	$4,545	$875	$6,855	$6,960
Unrealized	11,114	23,784	-669	7,461
Total	$15,659	$24,659	$6,186	$14,421

Reconciliation_of_Gross_Assets

Reconciliation of Gross Assets and Liabilities and Netting Agreements on Fair Value of Open Derivative Contracts (Details) (USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Derivative Assets	'
Fair value of commodity derivative contracts	$317
Amounts not offset in the balance sheet	-317
Net amounts	'
Derivative Liability	'
Fair value of commodity derivative contracts	9,050
Amounts not offset in the balance sheet	-317
Net amounts	$8,733

Schedule_of_LongTerm_Debt_Deta

Schedule of Long-Term Debt (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Long-term Debt unsecured	$900,000	$900,000
Debt premiums, net of amortization	15,984	17,611
Long-term debt secured	137,000	170,000
Total long-term debt	1,052,984	1,087,611
Current maturities of long-term debt	'	'
Long-term debt, less current maturities	$1,052,984	$1,087,611

Schedule_of_LongTerm_Debt_Pare

Schedule of Long-Term Debt (Parenthetical) (Detail)	Sep. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]	'	'
Senior notes interest rate	8.50%	8.50%

LongTerm_Debt_Additional_Infor

Long-Term Debt - Additional Information (Detail) (USD $)	9 Months Ended	12 Months Ended			1 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	15-May-12	Sep. 30, 2013
			Senior Notes	Senior Notes	Credit Agreement	Revolving Credit Facility
Debt Instrument [Line Items]	'	'	'	'	'	'
Senior notes interest rate	8.50%	8.50%	'	'	'	'
Senior notes payment terms	'Interest on the 8.50% Senior Notes is payable semi-annually in arrears on June 15 and December 15.	'Interest on the 8.50% Senior Notes is payable semi-annually in arrears on June 15 and December 15.	'	'	'	'
Effective interest rate	'	'	8.40%	8.40%	'	3.90%
Senior notes maturity date	15-Jun-19	'	'	'	'	'
Credit agreement expiration date	'	'	'	'	5-May-15	'
Letters of credit outstanding	$0.10	$0.10	'	'	'	'
Revolving bank credit facility borrowing base	800	'	'	'	'	'
Line of credit, borrowing availability	$662.90	'	'	'	'	'

Schedule_of_Fair_Value_of_Deri

Schedule of Fair Value of Derivatives Financial Instruments and Senior Notes (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Derivatives	'	'
Derivatives	8,733	'
Fair Value, Inputs, Level 2	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Derivatives	317	'
Derivatives	9,050	9,401
8.50% Senior Notes	977,625	963,000
Revolving bank credit facility	$137,000	$170,000

Summary_of_Share_Activity_Rela

Summary of Share Activity Related to Restricted Stock (Detail) (Restricted Stock, USD $)	9 Months Ended
	Sep. 30, 2013
Restricted Stock	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Shares, Nonvested, beginning of period	43,687
Shares, Granted	27,450
Shares, Vested	-27,297
Shares, Nonvested, end of period	43,840
Weighted Average Grant Date Value Per Share, Beginning of period	$18.69
Weighted Average Grant Date Fair Value Per Share, Granted	$12.75
Weighted Average Grant Date Fair Value Per Share, Vested	$17.09
Weighted Average Grant Date Value Per Share, End of period	$15.96

Outstanding_Restricted_Shares_

Outstanding Restricted Shares Issued to Non-employee Directors (Detail) (Restricted Stock)	9 Months Ended
	Sep. 30, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Awards expected to vest by period	43,840
2014	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Awards expected to vest by period	19,445
2015	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Awards expected to vest by period	15,245
2016	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Awards expected to vest by period	9,150

Summary_of_Share_Activity_Rela1

Summary of Share Activity Related to Restricted Stock Units (Detail) (Restricted Stock Units (RSUs), USD $)	9 Months Ended
	Sep. 30, 2013
Restricted Stock Units (RSUs)	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Shares, Nonvested, beginning of period	969,820
Shares, Granted	969,919
Shares, Forfeited	-33,042
Shares, Nonvested, end of period	1,906,697
Weighted Average Grant Date Value Per Share, Beginning of period	$22.70
Weighted Average Grant Date Fair Value Per Share, Granted	$13.23
Weighted Average Grant Date Fair Value Per Share, Forfeited	$18.86
Weighted Average Grant Date Value Per Share, End of period	$17.95

Restricted_Stock_Unit_Outstand

Restricted Stock Unit Outstanding (Detail) (Restricted Stock Units (RSUs))	9 Months Ended
	Sep. 30, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Awards expected to vest by period	1,906,697
2013 | Restricted Stock Units Subject To Service Requirements	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Awards expected to vest by period	470,536
2014 | Restricted Stock Units Subject To Service Requirements	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Awards expected to vest by period	335,555
2014 | Related to TSR Performance Measurements	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Awards expected to vest by period	138,330	[1]
2015 | Restricted Stock Units Subject To Service Requirements	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Awards expected to vest by period	23,500
2015 | Related to TSR Performance Measurements	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Awards expected to vest by period	281,633	[2]
2015 | Related to Company Performance Measurements	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Awards expected to vest by period	657,143	[3]
[1]	In addition to service requirements, these RSUs are also subject to TSR performance requirements not yet measureable, with awards ranging from 0% to 150% of amounts granted.
[2]	In addition to service requirements, these RSUs are also subject to TSR performance requirements not yet measureable, with awards ranging from 0% to 200% of amounts granted.
[3]	In addition to service requirements, these RSUs are also subject to certain Company-specific performance requirements not yet measureable, with awards ranging from 0% to 150% of amounts granted.

Summary_of_Compensation_Expens

Summary of Compensation Expense under Share-Based Payment Arrangements and Related Tax Benefit (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'
Share-based compensation	$3,507	$3,319	$8,457	$9,137
Tax benefit computed at the statutory rate	1,227	1,162	2,960	3,198
Restricted Stock	'	'	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'
Share-based compensation	99	110	297	324
Restricted Stock Units (RSUs)	'	'	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'
Share-based compensation	$3,408	$3,209	$8,160	$8,813

Summary_of_Incentive_Compensat

Summary of Incentive Compensation Expense (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]	'	'	'	'
Share-based compensation charged to operating income	$3,507	$3,319	$8,457	$9,137
Cash-based incentive compensation charged to operating income	2,915	3,995	10,609	7,772
Total incentive compensation charged to operating income	6,422	7,314	19,066	16,909
Lease Operating Expense	'	'	'	'
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]	'	'	'	'
Cash-based incentive compensation charged to operating income	724	947	2,864	2,846
General and Administrative Expense	'	'	'	'
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]	'	'	'	'
Cash-based incentive compensation charged to operating income	$2,191	$3,048	$7,745	$4,926

ShareBased_Compensation_and_Ca2

Share-Based Compensation and Cash-Based Incentive Compensation - Additional Information (Detail) (USD $)	9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Common stock available for award under the plans	5,393,602	'
Additional share authorized under share based compensation	4,000,000	'
Total Shareholder Return Performance Stock Awards	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Restricted share units TSR awards, range minimum	0.00%	'
Restricted share units TSR awards, range maximum	200.00%	'
Directors Compensation Plan	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Common stock available for award under the plans	519,379	'
Restricted Stock	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Shares granted, grant date fair value	$0.30	$0.40
Shares vested, grant date fair value	0.4	0.5
Unrecognized share-based compensation expense	0.6	'
Recognition period for unrecognized compensation expense	'2016-04	'
Restricted Stock Units (RSUs)	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Shares granted, grant date fair value	12.8	14.2
Unrecognized share-based compensation expense	$16.10	'
Recognition period for unrecognized compensation expense	'2015-11	'
Restricted Stock Units (RSUs) | LIBOR	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Risk-free interest rate, minimum	0.27%	0.15%
Risk-free interest rate, maximum	0.91%	0.72%
Restricted Stock Units (RSUs) | Minimum	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Expected volatility	30.00%	33.00%
Expected dividend yield	0.00%	0.00%
Correlation of movement of total shareholder return maximum range	-84.00%	-67.00%
Restricted Stock Units (RSUs) | Maximum	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Expected volatility	63.00%	74.00%
Expected dividend yield	3.10%	2.50%
Correlation of movement of total shareholder return maximum range	95.00%	94.00%

Schedule_of_Stock_Activity_Rel

Schedule of Stock Activity Related to Share-Based Compensation (Parenthetical) (Detail) (Restricted Stock Units (RSUs))	9 Months Ended
	Sep. 30, 2013
Minimum | 2014 | Related to TSR Performance Measurements	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Restricted Stock Units adjustments, percentage	0.00%
Minimum | 2015 | Related to TSR Performance Measurements	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Restricted Stock Units adjustments, percentage	0.00%
Minimum | 2015 | Related to Company Performance Measurements	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Restricted Stock Units adjustments, percentage	0.00%
Maximum | 2014 | Related to TSR Performance Measurements	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Restricted Stock Units adjustments, percentage	150.00%
Maximum | 2015 | Related to TSR Performance Measurements	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Restricted Stock Units adjustments, percentage	200.00%
Maximum | 2015 | Related to Company Performance Measurements	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'
Restricted Stock Units adjustments, percentage	150.00%

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Tax Expense (Benefit), Continuing Operations [Abstract]	'	'	'	'
Income tax expense (benefit)	$8,033,000	($2,175,000)	$35,358,000	$33,959,000
Effective tax rate	36.10%	59.70%	35.90%	38.00%
Federal statutory income tax rate	'	'	35.00%	'
Maximum	'	'	'	'
Income Tax Expense (Benefit), Continuing Operations [Abstract]	'	'	'	'
Accrued interest related to unrecognized tax benefit	100,000	'	100,000	'
Tax loss carrybacks to 2010 and 2011	'	'	'	'
Income Tax Expense (Benefit), Continuing Operations [Abstract]	'	'	'	'
Unrecognized tax benefits	9,500,000	'	9,500,000	'
Proceeds from income tax refunds	$59,100,000	'	$59,100,000	'

Schedule_of_Calculation_of_Bas

Schedule of Calculation of Basic Earnings Per Common Share (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share Basic [Line Items]	'	'	'	'
Net income	$14,194	($1,471)	$63,208	$55,315
Less portion allocated to nonvested shares	159	90	713	1,128
Net income (loss) allocated to common shares	$14,035	($1,561)	$62,495	$54,187
Weighted average common shares outstanding	75,233	74,327	75,221	74,315
Basic and diluted earnings (loss) per common share	$0.19	($0.02)	$0.83	$0.73
Shares excluded due to being anti-dilutive (weighted-average)	851	1,866	860	1,823

Dividends_Additional_Informati

Dividends - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		1 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Nov. 06, 2013
					Subsequent Event
Dividends Payable [Line Items]	'	'	'	'	'
Paid cash dividends, per share	'	'	$0.26	$0.24	'
Dividends declared per common share	$0.09	$0.08	$0.26	$0.24	$0.10
Dividend payable, date declared, day month and year	'	'	'	'	6-Nov-13
Dividends payable, date to be paid, day, month and year	'	'	'	'	3-Dec-13
Dividends payable, date of record, day, month and year	'	'	'	'	18-Nov-13

Contingencies_Additional_Infor

Contingencies - Additional Information (Detail) (USD $)	9 Months Ended		12 Months Ended			9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Dec. 31, 2009	Sep. 30, 2010	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
		Cameron Parish Louisiana Claim	Cameron Parish Louisiana Claim	Royalties	Royalties	Contingent Liability Recorded	Contingent Liability Recorded	Contingent Liability Recorded
Loss Contingencies [Line Items]	'	'	'	'	'	'	'	'
Claims paid	'	$1.30	$10	'	'	'	'	'
Costs incurred related to an insurance claim in dispute	45.3	'	'	'	'	'	'	'
Costs anticipated to be incurred related to an insurance claim in dispute	2.1	'	'	'	'	'	'	'
Allowable reductions of cash payments	'	'	'	5.3	'	'	'	'
Notified disallowed amount in reductions taken by ONRR	'	'	'	'	4.7	'	'	'
Expenses related to accrued and settled claims	'	'	'	'	'	0.3	8.8	'
Liability loss contingency	'	'	'	'	'	$0.10	'	$1.30

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (USD $)	9 Months Ended		9 Months Ended	0 Months Ended	1 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Nov. 08, 2013	Oct. 17, 2013
			Callon Properties	Subsequent Event	Subsequent Event
					Callon Properties
Subsequent Event [Line Items]	'	'	'	'	'
Total cash paid	'	'	'	'	$76,408,000
Percentage of working interest Medussa field	'	'	'	'	15.00%
Expenses associated with acquisition activities and transition activities	'	'	0	'	'
Oil and natural gas properties and equipment - full cost method, amount excluded from amortization	129,584,000	123,503,000	'	'	7,200,000
Long-term debt	1,052,984,000	1,087,611,000	'	'	76,400,000
Effective interest rate	'	'	'	'	2.00%
Federal statutory income tax rate	35.00%	'	'	'	35.00%
Credit facility, maximum borrowing capacity before fifth amendment	'	'	'	900,000,000	'
Credit facility, maximum borrowing capacity after fifth amendment	'	'	'	1,200,000,000	'
Credit facility, borrowing base amount	800,000,000	'	'	800,000,000	'
Credit agreement expiration date	'	'	'	8-Nov-18	'
Line of credit, capacity to issue letters of credit before fifth amendment	'	'	'	100,000,000	'
Line of credit, capacity to issue letters of credit after fifth amendment	'	'	'	$300,000,000	'
Maximum leverage ratio of debt to EBITDA	'	'	'	3	'
Increase in maximum leverage ratio of debt to EBITDA	'	'	'	3.5	'
Minimum current ratio	'	'	'	1	'

Preliminary_Purchase_Price_All

Preliminary Purchase Price Allocation for Acquisition of Callon Properties (Detail) (Subsequent Event, Callon Properties, USD $)	1 Months Ended
In Thousands, unless otherwise specified	Oct. 17, 2013
Subsequent Event | Callon Properties	'
Subsequent Event [Line Items]	'
Oil and natural gas properties and equipment	$79,136
Asset retirement obligations – current	-15
Asset retirement obligations – non-current	-2,713
Total cash paid	$76,408

Summary_of_Pro_form_Financial_

Summary of Pro form Financial Information for Acquisition of Callon Properties (Detail) (Callon Properties, Pro Forma, USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Callon Properties | Pro Forma	'	'	'	'
Business Acquisition [Line Items]	'	'	'	'
Revenues	$254,092	$197,076	$766,801	$670,881
Net income	$16,513	$858	$69,310	$63,801
Basic and diluted earnings per common share	$0.22	$0.01	$0.91	$0.84

Summary_of_Pro_Forma_Informati

Summary of Pro Forma Information Incremental Items, Callon Properties (Detail) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Business Acquisition [Line Items]	'		'		'		'
Revenues	$244,555		$185,946		$739,160		$637,345
Lease operating expenses	67,346		53,411		194,935		170,349
Depreciation, depletion, amortization and accretion	104,143		77,462		312,911		251,894
Incurred	21,373		14,791		64,157		43,409
Capitalized interest	2,573		3,383		7,537		9,899
Income tax expense (benefit)	8,033		-2,175		35,358		33,959
Callon Properties | Pro Forma	'		'		'		'
Business Acquisition [Line Items]	'		'		'		'
Revenues	9,537	[1]	11,130	[1]	27,641	[1]	33,536	[1]
Lease operating expenses	1,459	[1]	1,614	[1]	4,915	[1]	4,628	[1]
Insurance and acquisition costs, net	510	[2]	510	[2]	1,531	[2]	1,214	[2]
Depreciation, depletion, amortization and accretion	3,615	[3]	4,822	[3]	10,735	[3]	13,095	[3]
Incurred	382	[4]	382	[4]	1,146	[4]	1,146	[4]
Capitalized interest	4	[5]	219	[5]	-74	[5]	398	[5]
Income tax expense (benefit)	$1,248	[6]	$1,254	[6]	$3,286	[6]	$4,569	[6]
[1]	Revenues and direct operating expenses for the Callon Properties were derived from the unaudited historical financial records of Callon
[2]	Incremental costs for insurance were estimated from the incremental costs to add the Callon Properties included in the First Close to W&T’s insurance programs. The direct operating expenses for the Callon Properties described above exclude insurance costs
[3]	DD&A was estimated using the full-cost method and determined as the incremental DD&A expense due to adding the Callon Properties’ costs, reserves and production into our currently existing full cost pool in order to compute such amounts. The purchase price allocation included $7.2 million that was allocated to the pool of unevaluated properties for oil and natural gas interests. Accordingly, no DD&A expense was estimated for the unevaluated properties. ARO was estimated by W&T management
[4]	The acquisition was assumed to be funded entirely with borrowed funds. Interest expense was computed using assumed borrowings of $76.4 million, which equates to the cash component of the transaction, and an interest rate of 2.0%, which equates to the rates applied to incremental borrowings on the revolving bank credit facility
[5]	The change to capitalized interest was computed for the addition to the pool of unevaluated properties and the capitalization interest rate was adjusted for the assumed borrowings. Positive amounts represent increases to net expenses. The negative amount represents a decrease to net expenses
[6]	Income tax expense was computed using the 35% federal statutory rate

Condensed_Consolidating_Balanc

Condensed Consolidating Balance Sheet (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Current assets:	'	'	'	'
Cash and cash equivalents	$15,227	$12,245	$6,993	$4,512
Receivables:	'	'	'	'
Oil and natural gas sales	85,221	97,733	'	'
Joint interest and other	31,492	56,439	'	'
Income taxes	'	47,884	'	'
Total receivables	116,713	202,056	'	'
Restricted cash and cash equivalents	16,459	'	'	'
Prepaid expenses and other assets	32,850	25,822	'	'
Total current assets	181,249	240,123	'	'
Property and equipment – at cost:	'	'	'	'
Oil and natural gas properties and equipment	7,120,086	6,694,510	'	'
Furniture, fixtures and other	21,325	21,786	'	'
Total property and equipment	7,141,411	6,716,296	'	'
Less accumulated depreciation, depletion and amortization	4,950,768	4,655,841	'	'
Net property and equipment	2,190,643	2,060,455	'	'
Restricted deposits for asset retirement obligations	34,966	28,466	'	'
Other assets	16,842	19,943	'	'
Total assets	2,423,700	2,348,987	'	'
Current liabilities:	'	'	'	'
Accounts payable	129,988	123,885	'	'
Undistributed oil and natural gas proceeds	41,278	37,073	'	'
Asset retirement obligations	95,014	92,630	'	'
Accrued liabilities	51,048	21,021	'	'
Total current liabilities	317,328	274,609	'	'
Long-term debt	1,052,984	1,087,611	'	'
Asset retirement obligations, less current portion	267,093	291,423	'	'
Deferred income taxes	177,404	145,249	'	'
Other liabilities	15,859	8,908	'	'
Shareholders’ equity:	'	'	'	'
Common stock	1	1	'	'
Additional paid-in capital	404,604	396,186	'	'
Retained earnings	212,594	169,167	'	'
Treasury stock, at cost	-24,167	-24,167	'	'
Total shareholders’ equity	593,032	541,187	'	'
Total liabilities and shareholders’ equity	2,423,700	2,348,987	'	'
Parent Company	'	'	'	'
Current assets:	'	'	'	'
Cash and cash equivalents	15,227	12,245	6,993	4,512
Receivables:	'	'	'	'
Oil and natural gas sales	66,953	80,729	'	'
Joint interest and other	31,492	56,439	'	'
Income taxes	'	163,750	'	'
Total receivables	98,445	300,918	'	'
Restricted cash and cash equivalents	16,459	'	'	'
Prepaid expenses and other assets	152,739	25,822	'	'
Total current assets	282,870	338,985	'	'
Property and equipment – at cost:	'	'	'	'
Oil and natural gas properties and equipment	6,703,175	6,356,529	'	'
Furniture, fixtures and other	21,325	21,786	'	'
Total property and equipment	6,724,500	6,378,315	'	'
Less accumulated depreciation, depletion and amortization	4,690,550	4,461,886	'	'
Net property and equipment	2,033,950	1,916,429	'	'
Restricted deposits for asset retirement obligations	34,966	28,466	'	'
Other assets	481,029	442,540	'	'
Total assets	2,832,815	2,726,420	'	'
Current liabilities:	'	'	'	'
Accounts payable	130,021	123,792	'	'
Undistributed oil and natural gas proceeds	40,989	36,791	'	'
Asset retirement obligations	95,014	92,595	'	'
Accrued liabilities	45,272	20,755	'	'
Total current liabilities	311,296	273,933	'	'
Long-term debt	1,052,984	1,087,611	'	'
Asset retirement obligations, less current portion	235,782	262,524	'	'
Deferred income taxes	181,953	158,758	'	'
Other liabilities	457,768	402,407	'	'
Shareholders’ equity:	'	'	'	'
Common stock	1	1	'	'
Additional paid-in capital	404,604	396,186	'	'
Retained earnings	212,594	169,167	'	'
Treasury stock, at cost	-24,167	-24,167	'	'
Total shareholders’ equity	593,032	541,187	'	'
Total liabilities and shareholders’ equity	2,832,815	2,726,420	'	'
Guarantor Subsidiaries	'	'	'	'
Receivables:	'	'	'	'
Oil and natural gas sales	18,301	17,004	'	'
Total receivables	18,301	17,004	'	'
Prepaid expenses and other assets	3,991	'	'	'
Total current assets	22,292	17,004	'	'
Property and equipment – at cost:	'	'	'	'
Oil and natural gas properties and equipment	416,911	337,981	'	'
Total property and equipment	416,911	337,981	'	'
Less accumulated depreciation, depletion and amortization	260,218	193,955	'	'
Net property and equipment	156,693	144,026	'	'
Deferred income taxes	4,549	13,509	'	'
Other assets	441,908	393,499	'	'
Total assets	625,442	568,038	'	'
Current liabilities:	'	'	'	'
Accounts payable	'	93	'	'
Undistributed oil and natural gas proceeds	289	282	'	'
Accrued liabilities	129,656	116,132	'	'
Total current liabilities	129,945	116,507	'	'
Asset retirement obligations, less current portion	31,311	28,934	'	'
Shareholders’ equity:	'	'	'	'
Additional paid-in capital	231,759	231,759	'	'
Retained earnings	232,427	190,838	'	'
Total shareholders’ equity	464,186	422,597	'	'
Total liabilities and shareholders’ equity	625,442	568,038	'	'
Eliminations	'	'	'	'
Receivables:	'	'	'	'
Oil and natural gas sales	-33	'	'	'
Income taxes	'	-115,866	'	'
Total receivables	-33	-115,866	'	'
Prepaid expenses and other assets	-123,880	'	'	'
Total current assets	-123,913	-115,866	'	'
Property and equipment – at cost:	'	'	'	'
Deferred income taxes	-4,549	-13,509	'	'
Other assets	-906,095	-816,096	'	'
Total assets	-1,034,557	-945,471	'	'
Current liabilities:	'	'	'	'
Accounts payable	-33	'	'	'
Asset retirement obligations	'	35	'	'
Accrued liabilities	-123,880	-115,866	'	'
Total current liabilities	-123,913	-115,831	'	'
Asset retirement obligations, less current portion	'	-35	'	'
Deferred income taxes	-4,549	-13,509	'	'
Other liabilities	-441,909	-393,499	'	'
Shareholders’ equity:	'	'	'	'
Additional paid-in capital	-231,759	-231,759	'	'
Retained earnings	-232,427	-190,838	'	'
Total shareholders’ equity	-464,186	-422,597	'	'
Total liabilities and shareholders’ equity	($1,034,557)	($945,471)	'	'

Condensed_Consolidating_Statem

Condensed Consolidating Statement of Income (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Condensed Financial Statements Captions [Line Items]	'	'	'	'
Revenues	$244,555	$185,946	$739,160	$637,345
Operating costs and expenses:	'	'	'	'
Lease operating expenses	67,346	53,411	194,935	170,349
Production taxes	1,807	1,353	5,375	4,174
Gathering and transportation	3,611	2,810	12,663	11,140
Depreciation, depletion, amortization and accretion	104,143	77,462	312,911	251,894
General and administrative expenses	20,024	18,691	60,979	62,793
Derivative loss	15,659	24,659	6,186	14,421
Total costs and expenses	212,590	178,386	593,049	514,771
Operating income	31,965	7,560	146,111	122,574
Interest expense:	'	'	'	'
Incurred	21,373	14,791	64,157	43,409
Capitalized	-2,573	-3,383	-7,537	-9,899
Other income	9,062	202	9,075	210
Income before income tax expense	22,227	-3,646	98,566	89,274
Income tax expense (benefit)	8,033	-2,175	35,358	33,959
Net income	14,194	-1,471	63,208	55,315
Parent Company	'	'	'	'
Condensed Financial Statements Captions [Line Items]	'	'	'	'
Revenues	195,064	141,139	590,492	473,297
Operating costs and expenses:	'	'	'	'
Lease operating expenses	64,952	47,353	184,458	150,860
Production taxes	1,807	1,353	5,375	4,174
Gathering and transportation	2,706	2,084	10,099	8,788
Depreciation, depletion, amortization and accretion	80,230	58,744	244,597	189,827
General and administrative expenses	19,375	18,691	57,738	60,200
Derivative loss	15,659	24,659	6,186	14,421
Total costs and expenses	184,729	152,884	508,453	428,270
Operating income	10,335	-11,745	82,039	45,027
Earnings of affiliates	14,032	12,551	41,589	50,395
Interest expense:	'	'	'	'
Incurred	21,373	14,791	64,157	43,409
Capitalized	-2,573	-3,383	-7,537	-9,899
Other income	9,062	202	9,075	210
Income before income tax expense	14,629	-10,400	76,083	62,122
Income tax expense (benefit)	435	-8,929	12,875	6,807
Net income	14,194	-1,471	63,208	55,315
Guarantor Subsidiaries	'	'	'	'
Condensed Financial Statements Captions [Line Items]	'	'	'	'
Revenues	49,491	44,807	148,668	164,048
Operating costs and expenses:	'	'	'	'
Lease operating expenses	2,394	6,058	10,477	19,489
Gathering and transportation	905	726	2,564	2,352
Depreciation, depletion, amortization and accretion	23,913	18,718	68,314	62,067
General and administrative expenses	649	'	3,241	2,593
Total costs and expenses	27,861	25,502	84,596	86,501
Operating income	21,630	19,305	64,072	77,547
Interest expense:	'	'	'	'
Income before income tax expense	21,630	19,305	64,072	77,547
Income tax expense (benefit)	7,598	6,754	22,483	27,152
Net income	14,032	12,551	41,589	50,395
Eliminations	'	'	'	'
Operating costs and expenses:	'	'	'	'
Earnings of affiliates	-14,032	-12,551	-41,589	-50,395
Interest expense:	'	'	'	'
Income before income tax expense	-14,032	-12,551	-41,589	-50,395
Net income	($14,032)	($12,551)	($41,589)	($50,395)

Condensed_Consolidating_Statem1

Condensed Consolidating Statement of Cash Flows (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating activities:	'	'
Net income	$63,208	$55,315
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation, depletion, amortization and accretion	312,911	251,894
Amortization of debt issuance costs and premium	1,366	2,046
Share-based compensation	8,457	9,137
Derivative loss	6,186	14,421
Cash payments on derivative settlements	-6,855	-6,960
Deferred income taxes	31,581	44,465
Changes in operating assets and liabilities:	'	'
Oil and natural gas receivables	12,511	30,320
Joint interest and other receivables	24,947	3,935
Insurance receivables	5,117	500
Income taxes	53,433	-24,327
Prepaid expenses and other assets	-10,815	670
Asset retirement obligation settlements	-59,188	-63,150
Accounts payable, accrued liabilities and other	32,974	33,223
Net cash provided by operating activities	475,833	351,489
Investing activities:	'	'
Investment in oil and natural gas properties and equipment	-423,092	-312,372
Proceeds from sales of assets and other, net	21,011	30,453
Change in restricted cash	-16,459	-24,026
Purchases of furniture, fixtures and other	-1,327	-2,125
Net cash used in investing activities	-419,867	-330,870
Deposit for acquisition	'	-22,800
Financing activities:	'	'
Borrowings of long-term debt – revolving bank credit facility	335,000	316,000
Repayments of long-term debt – revolving bank credit facility	-368,000	-314,000
Debt issuance costs	-164	-2,081
Dividends to shareholders	-19,570	-17,848
Other	-250	-209
Net cash used in financing activities	-52,984	-18,138
Increase in cash and cash equivalents	2,982	2,481
Cash and cash equivalents, beginning of period	12,245	4,512
Cash and cash equivalents, end of period	15,227	6,993
Parent Company	'	'
Operating activities:	'	'
Net income	63,208	55,315
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation, depletion, amortization and accretion	244,597	189,827
Amortization of debt issuance costs and premium	1,366	2,046
Share-based compensation	8,457	9,137
Derivative loss	6,186	14,421
Cash payments on derivative settlements	-6,855	-6,960
Deferred income taxes	22,621	42,816
Earnings of affiliates	-41,589	-50,395
Changes in operating assets and liabilities:	'	'
Oil and natural gas receivables	13,775	24,162
Joint interest and other receivables	24,947	3,935
Insurance receivables	5,117	500
Income taxes	39,909	-49,830
Prepaid expenses and other assets	-6,823	669
Asset retirement obligation settlements	-59,017	-63,150
Accounts payable, accrued liabilities and other	81,501	136,449
Net cash provided by operating activities	397,400	308,942
Investing activities:	'	'
Investment in oil and natural gas properties and equipment	-344,659	-269,825
Proceeds from sales of assets and other, net	21,011	30,453
Change in restricted cash	-16,459	-24,026
Purchases of furniture, fixtures and other	-1,327	-2,125
Net cash used in investing activities	-341,434	-288,323
Deposit for acquisition	'	-22,800
Financing activities:	'	'
Borrowings of long-term debt – revolving bank credit facility	335,000	316,000
Repayments of long-term debt – revolving bank credit facility	-368,000	-314,000
Debt issuance costs	-164	-2,081
Dividends to shareholders	-19,570	-17,848
Other	-250	-209
Net cash used in financing activities	-52,984	-18,138
Increase in cash and cash equivalents	2,982	2,481
Cash and cash equivalents, beginning of period	12,245	4,512
Cash and cash equivalents, end of period	15,227	6,993
Guarantor Subsidiaries	'	'
Operating activities:	'	'
Net income	41,589	50,395
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation, depletion, amortization and accretion	68,314	62,067
Deferred income taxes	8,960	1,649
Changes in operating assets and liabilities:	'	'
Oil and natural gas receivables	-1,264	6,158
Income taxes	13,524	25,503
Prepaid expenses and other assets	-52,400	-101,473
Asset retirement obligation settlements	-171	'
Accounts payable, accrued liabilities and other	-119	-1,752
Net cash provided by operating activities	78,433	42,547
Investing activities:	'	'
Investment in oil and natural gas properties and equipment	-78,433	-42,547
Net cash used in investing activities	-78,433	-42,547
Eliminations	'	'
Operating activities:	'	'
Net income	-41,589	-50,395
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Earnings of affiliates	41,589	50,395
Changes in operating assets and liabilities:	'	'
Prepaid expenses and other assets	48,408	101,474
Accounts payable, accrued liabilities and other	($48,408)	($101,474)

Supplement_Guarantor_Informati

Supplement Guarantor Information - Additional Information (Detail)	Sep. 30, 2013	Dec. 31, 2012
Debt Disclosure [Line Items]	'	'
Senior notes interest rate	8.50%	8.50%