Kodiak Oil & Gas (KOG) 10-Q 31 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 30, 2013
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'Kodiak Oil & Gas Corp	'
Entity Central Index Key	'0001322866	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	266,026,558
Entity Current Reporting Status	'Yes	'

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current Assets:	'	'
Cash and cash equivalents	$18,318	$24,060
Accounts receivable	'	'
Trade	94,791	35,565
Accrued sales revenues	118,240	59,875
Commodity price risk management asset	0	10,864
Inventory, prepaid expenses and other	13,906	17,210
Total Current Assets	245,255	147,574
Oil and gas properties (full cost method), at cost:	'	'
Proved oil and gas properties	3,284,226	2,007,442
Unproved oil and gas properties	692,380	457,888
Equipment and facilities	27,580	20,954
Less-accumulated depletion, depreciation, amortization, and accretion	-505,758	-290,094
Net oil and gas properties	3,498,428	2,196,190
Commodity price risk management asset	1,475	2,850
Property and equipment, net of accumulated depreciation of $1,687 at September 30, 2013 and $1,113 at December 31, 2012	3,085	1,846
Deferred financing costs, net of amortization of $21,461 at September 30, 2013 and $17,995 at December 31, 2012	42,071	25,176
Total Assets	3,790,314	2,373,636
Current Liabilities:	'	'
Accounts payable and accrued liabilities	294,623	190,596
Accrued interest payable	30,473	6,090
Commodity price risk management liability	29,005	304
Total Current Liabilities	354,101	196,990
Noncurrent Liabilities:	'	'
Credit facilities	638,000	295,000
Senior notes, net of accumulated amortization of bond premium of $858 at September 30, 2013 and $378 at December 31, 2012	1,555,142	805,622
Commodity price risk management liability	1,054	4,288
Deferred tax liability, net	85,200	26,800
Asset retirement obligations	13,927	9,064
Total Noncurrent Liabilities	2,293,323	1,140,774
Total Liabilities	2,647,424	1,337,764
Stockholders’ Equity:	'	'
Common stock—no par value; unlimited authorized Issued and outstanding: 266,026,558 shares as of September 30, 213 and 265,273,314 shares as of December 31, 2012	1,020,852	1,008,678
Retained earnings (accumulated deficit)	122,038	27,194
Total Stockholders’ Equity	1,142,890	1,035,872
Total Liabilities and Stockholders’ Equity	$3,790,314	$2,373,636

CONSOLIDATED_BALANCE_SHEETS_PA

CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Property and equipment, accumulated depreciation	$1,687	$1,113
Deferred financing costs, accumulated amortization	21,461	17,995
Accumulated amortization of bond premium	$858	$378
Common Stock, Par or Stated Value Per Share	$0	$0
Common stock, Issued shares	266,026,558	265,273,314
Common stock, outstanding shares	266,026,558	265,273,314

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues:	'	'	'	'
Oil sales	$286,832	$106,798	$606,044	$266,002
Gas sales	12,760	5,342	32,076	11,842
Total revenues	299,592	112,140	638,120	277,844
Operating expenses:	'	'	'	'
Oil and gas production	59,132	22,950	132,654	57,450
Depletion, depreciation, amortization and accretion	97,094	43,720	216,888	104,204
General and administrative	12,560	9,126	33,188	25,166
Total operating expenses	168,786	75,796	382,730	186,820
Operating income	130,806	36,344	255,390	91,024
Other income (expense):	'	'	'	'
Gain (loss) on commodity price risk management activities, net	-60,108	-31,652	-53,185	40,580
Interest income (expense), net	-21,049	-6,390	-50,644	-14,558
Other income	1,001	1,194	1,683	3,186
Total other income (expense)	-80,156	-36,848	-102,146	29,208
Income (loss) before income taxes	50,650	-504	153,244	120,232
Income tax expense (benefit)	19,500	-3,980	58,400	21,940
Net income	$31,150	$3,476	$94,844	$98,292
Net income (loss) per common share:	'	'	'	'
Basic (in dollars per share)	$0.12	$0.01	$0.36	$0.37
Diluted (in dollars per share)	$0.12	$0.01	$0.35	$0.37
Weighted average common shares outstanding:	'	'	'	'
Basic (in shares)	265,733,881	263,756,896	265,500,414	263,332,764
Diluted (in shares)	268,566,065	267,403,802	267,992,098	267,532,393

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:	'	'
Net income	$94,844	$98,292
Reconciliation of net income (loss) to net cash provided by operating activities:	'	'
Depletion, depreciation, amortization and accretion	216,888	104,204
Amortization of deferred financing costs and debt premium	2,985	1,900
Gain (loss) on commodity price risk management activities, net	53,185	-40,580
Settlements on commodity derivative instruments	-15,479	4,192
Stock‑based compensation	11,105	7,855
Income tax expense (benefit)	58,400	21,940
Changes in current assets and liabilities:	'	'
Accounts receivable‑trade	-59,226	-10,090
Accounts receivable‑accrued sales revenue	-58,365	-26,114
Prepaid expenses and other	-1,159	7,860
Accounts payable and accrued liabilities	57,974	14,413
Accrued interest payable	24,383	16,040
Cash held in escrow	0	3,343
Net cash provided by operating activities	385,535	203,255
Cash flows from investing activities:	'	'
Acquired oil and gas properties and facilities	-759,025	-588,420
Oil and gas properties	-767,814	-527,019
Sale of oil and gas properties	87,370	2,752
Equipment, facilities and other	-8,338	-8,160
Tubular goods	-17,179	-29,920
Cash held in escrow	0	30,000
Net cash used in investing activities	-1,464,986	-1,120,767
Cash flows from financing activities:	'	'
Borrowings under credit facilities	1,194,875	200,000
Repayments under credit facilities	-851,875	-185,000
Proceeds from the issuance of senior notes	750,000	156,000
Proceeds from the issuance of common shares	2,283	1,870
Purchase of common shares	-1,214	0
Cash held in escrow	0	670,615
Debt and share issuance costs	-20,360	-5,827
Net cash provided by financing activities	1,073,709	837,658
Increase (decrease) in cash and cash equivalents	-5,742	-79,854
Cash and cash equivalents at beginning of the period	24,060	81,604
Cash and cash equivalents at end of the period	18,318	1,750
Supplemental cash flow information:	'	'
Oil & gas property accrual included in accounts payable and accrued liabilities	201,438	124,155
Oil & gas property acquired through common stock	0	49,798
Cash paid for interest	$48,912	$32,354

Organization

Organization	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Organization	'
	Organization
	Description of Operations
	Kodiak Oil & Gas Corp. is a public company listed for trading on the New York Stock Exchange under the symbol: “KOG”. The Company's corporate headquarters are located in Denver, Colorado, USA. The Company is an independent energy company engaged in the exploration, exploitation, development, acquisition and production of crude oil and natural gas entirely in the Rocky Mountain region of the United States. Kodiak Oil & Gas Corp. was incorporated (continued) in the Yukon Territory on September 28, 2001. The Company and its wholly-owned subsidiaries, Kodiak Oil & Gas (USA) Inc., KOG Finance, LLC, KOG Oil & Gas, ULC and Kodiak Williston, LLC, are collectively referred to herein as “Kodiak” or the “Company”.

Basis_of_Presentation_and_Sign

Basis of Presentation and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Basis of Presentation and Significant Accounting Policies	'
	Basis of Presentation and Significant Accounting Policies
	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant inter-company balances and transactions have been eliminated in consolidation. The Company's business is transacted in US dollars and, accordingly, the financial statements are expressed in US dollars. The financial statements included herein were prepared from the records of the Company in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information and the instructions to Form 10-Q and Regulation S-X and S-K. In the opinion of management, all adjustments, consisting of normal recurring accruals that are considered necessary for a fair presentation of the interim financial information, have been included. However, operating results for the periods presented are not necessarily indicative of the results that may be expected for a full year. Kodiak's 2012 Annual Report on Form 10-K includes certain definitions and a summary of significant accounting policies and should be read in conjunction with this Form 10-Q. Except as disclosed herein, there have been no material changes to the information disclosed in the notes to the consolidated financial statements included in Kodiak's 2012 Annual Report on Form 10-K.
	The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of oil and gas reserves, 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 period. Significant areas requiring the use of assumptions, judgments and estimates include (1) oil and gas reserves; (2) cash flow estimates used in the ceiling test of oil and natural gas properties; (3) depreciation, depletion and amortization; (4) asset retirement obligations; (5) assigning fair value and allocating purchase price in connection with business combinations; (6) accrued revenue and related receivables; (7) valuation of commodity derivative instruments; (8) accrued liabilities; (9) valuation of share-based payments and (10) income taxes. Although management believes these estimates are reasonable, actual results could differ from these estimates. The Company evaluates its estimates on an on-going basis and bases its estimates on historical experience and on various other assumptions the Company believes to be reasonable under the circumstances. Although actual results may differ from these estimates under different assumptions or conditions, the Company believes that its estimates are reasonable.
	Recent Accounting Pronouncements
	In December 2011, the Financial Accounting Standards Board issued Accounting Standards Update 2011-11 (“ASU 2011-11”), Balance Sheet: 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: 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 records its derivative financial instruments on a net basis by contract. The adoption of this standard had no impact on the Company’s financial position or results of operations, but did require enhanced disclosures regarding derivative instruments. Please refer to Note 6 - Commodity Derivative Instruments for the enhanced disclosures.
	Other accounting standards that have been issued or proposed by the FASB, or other standards-setting bodies, that do not require adoption until a future date, are not expected to have a material impact on the financial statements upon adoption.

Acquisitions_and_Divestitures_

Acquisitions and Divestitures (Notes)	9 Months Ended
	Sep. 30, 2013
Acquisitions and Divestitures [Abstract]	'
Acquisitions and Divestitures	'
	Acquisitions and Divestitures
	July 2013 Acquisition
	On July 12, 2013, the Company's subsidiary, Kodiak Williston, LLC, acquired an unaffiliated oil and gas company’s interests in approximately 42,000 net acres of Williston Basin leaseholds, and related producing properties located primarily in McKenzie and southern Williams Counties, North Dakota, along with various other related rights, permits, contracts, equipment and other assets, including the assignment and assumption of a drilling rig contract (the "July 2013 Acquisition"). The seller received aggregate consideration of approximately $731.8 million in cash. The effective date for the acquisition was March 1, 2013, with purchase price adjustments calculated as of the closing date on July 12, 2013. The acquisition provided strategic additions adjacent to the Company's core project area. The acquisition contributed revenue of $40.4 million to Kodiak for both the three and nine months ended September 30, 2013. The acquisition contributed no revenue to Kodiak for the three and nine months ended September 30, 2012. Transaction costs related to the acquisition incurred through September 30, 2013 were approximately $185,000 and are recorded in the statement of operations within the general and administrative expenses line item. The Company estimates an additional $20,000 of transaction costs will be incurred in the fourth quarter of 2013.
	The acquisition is accounted for using the acquisition method under ASC 805, Business Combinations, which requires the acquired assets and liabilities to be recorded at fair values as of the acquisition date of July 12, 2013. Management has not had the opportunity to complete its assessment of the fair values of assets acquired and liabilities assumed. Accordingly, the allocation will change as additional information becomes available and is assessed by the Company, and the impact of such changes may be material. The following table summarizes the preliminary purchase price and the preliminary estimated values of assets acquired and liabilities assumed (in thousands):
	Purchase Price	12-Jul-13
	Consideration Given
	Cash from credit facility	$	731,785
	Total consideration given	$	731,785
	Allocation of Purchase Price
	Proved oil and gas properties	$	393,917
	Unproved oil and gas properties	317,980
	Total fair value of oil and gas properties acquired	$	711,897
	Working capital	$	22,115
	Asset retirement obligation	(2,227		)
	Fair value of net assets acquired	$	731,785
	Working capital acquired was estimated as follows:
	Accounts receivable	$	60,418
	Accrued liabilities	(38,303		)
	Total working capital	$	22,115
	Pro Forma Financial Information
	The following unaudited pro forma financial information represents the combined results for the Company and the properties acquired in July 2013 for the for the three and nine months ended September 30, 2013 and 2012 as if the acquisition had occurred on January 1, 2012 (in thousands, except per share data). For purposes of the pro forma it was assumed that the credit facility was utilized on January 1, 2012. The pro forma information includes the effects of adjustments for depletion, depreciation, amortization and accretion expense of $1.0 million and $23.5 million for the three and nine months ended September 30, 2013, respectively, as compared to $9.3 million and $14.2 million for the three and nine months ended September 30, 2012, respectively. The pro forma information includes the effects of adjustments for amortization of financing costs of $26,000 and $434,000 for the three and nine months ended September 30, 2013, respectively, as compared to $204,000 and $612,000 for the three and nine months ended September 30, 2012, respectively. The pro forma information includes the effects of the incremental interest expense on acquisition financing of $600,000 and $5.5 million for the three and nine months ended September 30, 2013, respectively, as compared to $3.9 million and $13.8 million for the three and nine months ended September 30, 2012, respectively. The pro forma financial information includes total capitalization of interest expense of $9.7 million and $29.9 million for the three and nine months ended September 30, 2013, respectively as compared to $11.9 million and $35.7 million for the three and nine months ended September 30, 2012, respectively. The pro forma information includes the effects of adjustments for income tax expense of $480,000 and $12.5 million for the three and nine months ended September 30, 2013, respectively, as compared to $4.6 million and $4.7 million for the three and nine months ended September 30, 2012, respectively. The pro forma results do not include any cost savings or other synergies that may result from the acquisition or any estimated costs that have been or will be incurred by the Company to integrate the properties acquired. The pro forma results are not necessarily indicative of what actually would have occurred if the acquisition had been completed as of the beginning of the period, nor are they necessarily indicative of future results.
		For the Three Months Ended September 30,					For the Nine Months Ended September 30,
		2013			2012		2013		2012
	Operating revenues	$	302,692		$	144,025	$	724,060	$	329,860
	Net income	$	31,935		$	11,020	$	115,225	$	105,946
	Earnings per common share
	Basic	$	0.12		$	0.04	$	0.43	$	0.4
	Diluted	$	0.12		$	0.04	$	0.43	$	0.4
	Other Acquisitions, Divestitures, and Trades
	During the third quarter of 2013, through various trades, acquisitions and divestitures, the Company divested approximately 3,700 net acres in the Williston Basin. As a result of certain acquisitions that were accounted for as Business Combinations, the Company recorded $41.8 million to proved properties and $4.1 million to unproved properties based on the estimated values of assets acquired and liabilities assumed. These acquisitions contributed no material revenue to Kodiak for the three and nine months ended September 30, 2013 and contributed no revenue to Kodiak for the three and nine months ended September 30, 2012. As these acquisitions were deemed insignificant, no pro forma financial information is provided. Net proceeds from all of the acquisitions and divestitures were approximately $36.7 million and the gross value of the non-monetary transactions was not significant. As a result of these transactions, the Company was able to divest or trade out of non-operated units and increase its working interest in operated units.

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Long-Term Debt	'
	Long-Term Debt
	As of the dates indicated, the Company’s long-term debt consisted of the following (in thousands):
		September 30, 2013			December 31, 2012
	Credit Facility due April 2018	$	638,000		$	295,000
	2019 Notes due December 2019	800,000			800,000
	Unamortized Premium on 2019 Notes	5,142			5,622
	2021 Notes due January 2021	350,000			—
	2022 Notes due February 2022	400,000			—
	Total Long-Term Debt	$	2,193,142		$	1,100,622
	Less: Current Portion of Long-Term Debt	—			—
	Total Long-Term Debt, Net of Current Portion	$	2,193,142		$	1,100,622
	Credit Facility
	Kodiak Oil & Gas (USA) Inc. (the “Borrower”), a wholly-owned subsidiary of Kodiak Oil & Gas Corp., has in place a credit facility with a syndicate of banks. The credit facility matures on April 2, 2018. As of September 30, 2013, the maximum credit available under the credit facility was $1.5 billion with a borrowing base and aggregate commitment of $1.1 billion. Redetermination of the borrowing base occurs semi-annually, on April 1 and October 1. Additionally, the Company may elect a redetermination of the borrowing base one time during any six month period. On July 12, 2013, in conjunction with the July 2013 Acquisition, the Company entered into an amendment with its lenders increasing the borrowing base on its credit facility to $1.1 billion. In connection with the issuance of the 2022 Notes (as discussed below), the lenders under the Company’s credit facility agreed to waive provisions that would have otherwise resulted in a reduction in the borrowing base under the credit facility upon consummation of the offering.
	Interest on the credit facility is payable at one of the following two variable rates: the alternate base rate for ABR loans or the adjusted LIBO rate for Eurodollar loans, as selected by the Company, plus an additional percentage that can vary on a daily basis and is based on the daily unused portion of the credit facility. This additional percentage is referred to as the “Applicable Margin” and varies depending on the type of loan. As of the date of this filing, the Applicable Margin for the ABR loans is a sliding scale of 0.50% to 1.50%, depending on borrowing base usage. The Applicable Margin on the adjusted LIBO rate is a sliding scale of 1.50% to 2.50%, depending on borrowing base usage. Additionally, the credit facility provides for a commitment fee of 0.375% to 0.50%, depending on borrowing base usage. The grid below shows the Applicable Margin options depending on the applicable Borrowing Base Utilization Percentage (as defined in the credit facility) as of the date of this filing:
	Borrowing Base Utilization Grid
	Borrowing Base Utilization Percentage	<25.0%		>25.0% <50.0%			>50.0% <75.0%		>75.0% <90.0%		>90.0%
	Eurodollar Loans	1.5	%	1.75	%		2	%	2.25	%	2.5	%
	ABR Loans	0.5	%	0.75	%		1	%	1.25	%	1.5	%
	Commitment Fee Rate	0.375	%	0.375	%		0.5	%	0.5	%	0.5	%
	The credit facility contains representations, warranties, covenants, conditions and defaults customary for transactions of this type, including but not limited to: (i) limitations on liens and incurrence of debt covenants; (ii) limitations on dividends, distributions, redemptions and restricted payments covenants; (iii) limitations on investments, loans and advances covenants; and (iv) limitations on the sale of property, mergers, consolidations and other similar transactions covenants. Additionally, the credit facility requires the Borrower to enter into hedging agreements necessary to support the borrowing base.
	The credit facility also contains financial covenants requiring the Borrower to comply with a current ratio of consolidated current assets (including unused borrowing capacity) to consolidated current liabilities of not less than 1.0 to 1.0 and to maintain on the last day of each quarter, a ratio of total debt to EBITDAX of not greater than 4.0 to 1.0 at the end of each fiscal quarter. The Company was in compliance with all financial covenants under the credit facility as of September 30, 2013, and through the filing of this report.
	As of September 30, 2013, the Company had $638.0 million in outstanding borrowings under the credit facility and as such, the available credit under the credit facility at that date was $462.0 million. Subsequent to September 30, 2013, the Company made additional borrowings of $40.0 million, bringing the outstanding balance as of the date of this filing under the credit facility to $678.0 million. Any borrowings under the credit facility are collateralized by the Borrower's oil and gas producing properties, the Borrower's personal property and the equity interests of the Borrower held by the Company. Borrowings under the credit facility are also guaranteed by the Company's subsidiaries other than the Borrower. The Company has entered into crude oil hedging transactions with several counterparties that are also lenders under the credit facility. The Company’s obligations under these hedging contracts are secured by the credit facility.
	Second Lien Credit Agreement
	On January 10, 2012, the Company terminated its second lien credit agreement and repaid the $100.0 million of outstanding debt, and incurred a $3.0 million prepayment penalty in connection therewith. The Company recorded the $3.0 million prepayment penalty in the first quarter of 2012 within the interest income (expense), net line item of the statements of operations.
	Senior Notes
	In November 2011, the Company issued at par $650.0 million principal amount of 8.125% Senior Notes due December 1, 2019 and in May 2012, the Company issued at a price of 104.0% of par an additional $150.0 million aggregate principal amount of 8.125% Senior Notes due December 1, 2019 (the “2019 Notes”). The 2019 Notes bear an annual interest rate of 8.125%. The interest on the 2019 Notes is payable on June 1 and December 1 of each year. The issuance of the 2019 Notes resulted in aggregate net proceeds of approximately $784.2 million after deducting discounts and fees. The Company used the proceeds from the 2019 Notes to fund its acquisition program and repay outstanding borrowings under its credit facility and second lien credit agreement and for general corporate purposes.
	In January 2013, the Company issued at par $350.0 million principal amount of 5.50% Senior Notes due January 15, 2021 (the "2021 Notes"). The 2021 Notes bear an annual interest rate of 5.50%. The interest on the 2021 Notes is payable on January 15 and July 15 of each year. The Company received net proceeds of approximately $343.1 million after deducting discounts and fees. All of the net proceeds from the 2021 Notes were used to repay borrowings on the Company's credit facility.
	In July 2013, the Company issued at par $400.0 million principal amount of 5.50% Senior Notes due February 1, 2022 (the "2022 Notes" and together with the 2019 Notes and 2021 Notes, the "Senior Notes"). The 2022 Notes bear an annual interest rate of 5.50%. The interest on the 2022 Notes is payable on February 1 and August 1 of each year commencing on February 1, 2014. The Company received net proceeds of approximately $391.8 million after deducting discounts and fees. All of the net proceeds from the 2022 Notes were used to repay borrowings on the Company's credit facility.
	The 2019 Notes and 2021 Notes were issued under separate indentures among the Company, Kodiak Oil & Gas (USA) Inc., as guarantor, U.S. Bank National Association, as trustee, and Computershare Trust Company of Canada, as Canadian trustee (the “2019 Indenture” and the “2021 Indenture”, respectively). The 2022 Notes were issued under an indenture among the Company, Kodiak Oil & Gas (USA) Inc., Kodiak Williston, LLC and KOG Finance, LLC (collectively, the “Guarantors”), U.S. Bank National Association, as trustee, and Computershare Trust Company of Canada, as Canadian trustee (the “2022 Indenture”, and together with the 2019 Indenture and the 2021 Indenture, the “Indentures”). In July 2013, the Kodiak Williston, LLC and KOG Finance, LLC entered into Supplemental Indentures to the 2019 Indenture and 2021 Indenture to guarantee the 2019 Notes and 2021 Notes. The Indentures contain affirmative and negative covenants that, among other things, limit the Company's and the Guarantors' ability to make investments; incur additional indebtedness or issue preferred stock; create liens; sell assets; enter into agreements that restrict dividends or other payments by restricted subsidiaries; consolidate, merge or transfer all or substantially all of the assets of the Company; engage in transactions with the Company's affiliates; pay dividends or make other distributions on capital stock or prepay subordinated indebtedness; and create unrestricted subsidiaries. The Indentures also contain customary events of default. Upon the occurrence of events of default arising from certain events of bankruptcy or insolvency, the Senior Notes shall become due and payable immediately without any declaration or other act of the trustee or the holders of the Senior Notes. Upon the occurrence of certain other events of default, the trustee or the holders of the Senior Notes may declare all outstanding Senior Notes to be due and payable immediately. The Company was in compliance with all financial covenants under the Indentures as of September 30, 2013, and through the filing of this report.
	The 2019 Notes are redeemable by the Company at any time on or after December 1, 2015, the 2021 Notes are redeemable by the Company at any time on or after January 15, 2017, and the 2022 Notes are redeemable by the Company at any time on or after August 1, 2017, in each case, at the redemption prices set forth in the indentures. Further, the 2019 Notes are redeemable by the Company prior to December 1, 2015, the 2021 Notes are redeemable by the Company prior to January 15, 2017, and the 2022 Notes are redeemable by the Company prior to August 1, 2017, in each case, at the redemption prices plus a “make-whole” premium set forth in the Indentures. The Company is also entitled to redeem up to 35% of the aggregate principal amount of the 2019 Notes before December 1, 2014, up to 35% of the aggregate principal amount of the 2021 Notes before January 15, 2016, and up to 35% of the aggregate principal amount of the 2022 Notes before August 1, 2016, with net proceeds that the Company raises in equity offerings at a redemption price equal to 108.125% of the principal amount of the 2019 Notes being redeemed and 105.5% of the principal amount of the 2021 Notes being redeemed and 105.5% of the principal amount of the 2022 Notes being redeemed, plus, in each case, accrued and unpaid interest. If the Company undergoes a change of control, it may redeem all, but not less than all, of the Senior Notes at a redemption price equal to 101% of the principal amount of the Senior Notes redeemed plus accrued and unpaid interest. The Company may redeem the Senior Notes if, as a result of changes in applicable law, it is required to pay additional amounts related to tax-withholdings, at a price equal to 100% of the Senior Notes plus accrued and unpaid interest. The Company must offer to purchase the Senior Notes if it sells assets under certain circumstances.
	On November 16, 2012, the Company closed a registered exchange offer with respect to the 2019 Notes pursuant to which all of the holders of the privately placed 2019 Notes exchanged their notes for SEC-registered 2019 Notes. With respect to the 2021 Notes and 2022 Notes, the Company must either (1) file an exchange offer registration statement to allow the holders to exchange the Senior Notes for SEC-registered notes and (2) file, under certain circumstances, a shelf registration statement to cover resales of the 2021 Notes and/or the 2022 Notes. If the Company were to fail to complete the registered exchange offer or the shelf registration statement were not to be declared effective within specified time periods, the Company would be required to pay liquidated damages by way of additional interest on the 2021 Notes and/or the 2022 Notes. On September 20, 2013, the Company filed a registration statement on Form S-4 (No. 333-191281) in accordance with the registration rights agreements associated with the privately placed 2021 Notes and 2022 Notes. The SEC declared the registration statement effective on October 29, 2013. On October 30, 2013, the Company commenced registered exchange offers pursuant to which all holders of the privately placed 2021 Notes and 2022 Notes may exchange their notes for registered 2021 Notes and 2022 Notes, respectively. The Company expects to close each exchange offer on December 2, 2013.
	Deferred Financing Costs
	As of September 30, 2013, the Company had deferred financing costs of $42.1 million related to its credit facility and Senior Notes. Deferred financing costs include origination, legal, engineering, and other fees incurred in connection with the Company’s credit facility and Senior Notes. For the three and nine months ended September 30, 2013, the Company recorded amortization expense of $1.4 million and $3.5 million, respectively, as compared to $794,000 and $2.1 million for the three and nine months ended September 30, 2012, respectively.
	Interest Incurred On Long-Term Debt
	For the three and nine months ended September 30, 2013, the Company incurred interest expense on long-term debt of $29.5 million and $73.3 million, respectively, as compared to $17.0 million and $45.4 million for the three and nine months ended September 30, 2012, respectively. Of the total interest incurred, the Company capitalized interest costs of $9.7 million and $25.6 million for the three and nine months ended September 30, 2013, respectively, as compared to $11.2 million and $35.7 million for the three and nine months ended September 30, 2012, respectively. Additionally, for the three and nine months ended September 30, 2013, interest expense was reduced for the amortization of the bond premium in the amounts of $163,000 and $480,000, respectively, as compared to $151,000 and $224,000 for the three and nine months ended September 30, 2012, respectively.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Taxes [Abstract]	'
Income Taxes	'
	Income Taxes
	The Company computes its quarterly taxes under the effective tax rate method based on applying an anticipated annual effective rate to its year-to-date income or loss plus any significant unusual or infrequently occurring items recorded in the interim period. The effective income tax rate for the nine months ended September 30, 2013 and 2012 was 38.1% and 18.3% respectively. The Company's effective income tax rate for the nine months ended September 30, 2013 differed from the U.S. statutory rate of 35% primarily due to state income taxes, estimated permanent differences and a valuation allowance applied to the foreign jurisdiction loss. The Company's effective income tax rate for the nine months ended September 30, 2012 differed from the U.S. statutory rate of 35% due to state income tax, estimated permanent differences, and primarily due to the release of the U.S valuation allowance against its U.S. deferred tax assets.
	The Company continues to provide a full valuation allowance on the Canadian net deferred tax assets as ultimate realization of these deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. At each reporting period, management considers the scheduled reversal of deferred tax liabilities, available taxes in carryback periods, projected future taxable income and tax planning strategies in making this assessment. As the Company does not have revenue generating assets in Canada, the Company does not expect to utilize the Canadian net deferred tax assets. The Company will continue to evaluate whether a valuation allowance on a separate country basis is needed in future reporting periods.
	Accounting for Uncertainty in Income Taxes
	As of September 30, 2013, the Company believes that it has no liability for uncertain tax positions. If the Company were to determine there were any uncertain tax positions, the Company would recognize the liability and related interest and penalties within income tax expense. As of September 30, 2013, the Company had no provision for interest or penalties related to uncertain tax positions. The Company files income tax returns in Canada and U.S. federal jurisdiction and various states. There are currently no Canadian or U.S. federal or state income tax examinations underway for these jurisdictions. Furthermore, the Company is no longer subject to U.S. federal income tax examinations by the Internal Revenue Service, state or local tax authorities for tax years ended on or before December 31, 2009 or Canadian tax examinations by the Canadian Revenue Agency for tax years ended on or before December 31, 2002. Although certain tax years are closed under the statute of limitations, tax authorities can still adjust tax losses being carried forward to open tax years.

Commodity_Derivative_Instrumen

Commodity Derivative Instruments	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Commodity Derivative Instruments	'
	Commodity Derivative Instruments
	Through its wholly‑owned subsidiary Kodiak Oil & Gas (USA) Inc., the Company has entered into commodity derivative instruments, as described below. The Company has utilized swaps and “no premium” collars to reduce the effect of price changes on a portion of the Company's future oil production. A collar requires the Company to pay the counterparty if the settlement price is above the ceiling price and requires the counterparty to pay the Company if the settlement price is below the floor price. A swap requires the Company to pay the counterparty if the settlement price exceeds the strike price and the same counterparty is required to pay the Company if the settlement price is less than the strike price. The objective of the Company’s use of derivative financial instruments is to achieve more predictable cash flows in an environment of volatile oil and gas prices and to manage its exposure to commodity price risk. While the use of these derivative instruments limits the downside risk of adverse price movements, such use may also limit the Company’s ability to benefit from favorable price movements. The Company may, from time to time, add incremental derivatives to hedge additional production, restructure existing derivative contracts or enter into new transactions to modify the terms of current contracts in order to realize the current value of the Company’s existing positions. The Company does not enter into derivative contracts for speculative purposes.
	The use of derivatives involves the risk that the counterparties to such instruments will be unable to meet the financial terms of such contracts. The Company’s derivative contracts are currently with nine counterparties. The Company has netting arrangements with the counterparties that provide for the offset of payables against receivables from separate derivative arrangements with the counterparties in the event of contract termination. The derivative contracts may be terminated by a non-defaulting party in the event of default by one of the parties to the agreement.
	The Company’s commodity derivative instruments are measured at fair value and are included in the accompanying balance sheets as commodity price risk management assets and liabilities. The Company has not designated any of its derivative contracts as fair value or cash flow hedges. Therefore, the Company does not apply hedge accounting to its commodity derivative instruments. Net gains and losses on commodity price risk management activities are recorded based on the changes in the fair values of the derivative instruments. Net gains and losses on commodity price risk management activities are recorded in the commodity price risk management activities line on the consolidated statements of income. The Company’s cash flow is only impacted when the actual settlements under the commodity derivative contracts result in making or receiving a payment to or from the counterparty. These settlements under the commodity derivative contracts are reflected as operating activities in the Company’s consolidated statements of cash flows.
	The Company’s valuation estimate takes into consideration the counterparties’ credit worthiness, the Company’s credit worthiness, and the time value of money. The consideration of the factors results in an estimated exit-price for each derivative asset or liability under a market place participant’s view. Management believes that this approach provides a reasonable, non-biased, verifiable, and consistent methodology for valuing commodity derivative instruments.
	The Company’s commodity derivative contracts as of September 30, 2013 are summarized below:
	Collars		Basis(1)	Quantity (Bbl/d)		Strike Price
						($/Bbl)
	Oct 1, 2013—Dec 31, 2013		NYMEX	500		$85.00 - $117.00
	Oct 1, 2013—Dec 31, 2015		NYMEX	300 - 425		$85.00 - $102.75
	Swaps		Basis (1)	Average Quantity (Bbl/d)		Average Swap Price
						($/Bbl)
	Oct 1, 2013—Dec 31, 2013		NYMEX	22,105		$96.82
	2014 Total		NYMEX	19,800		$92.73
	2015 Total		NYMEX	1,625		$87.13
	Subsequent to September 30, 2013, the Company entered into additional commodity derivative contracts as summarized below:
	Contract Type		Basis (1)	Average Quantity (Bbl/d)		Average Swap Price	Term
						($/Bbl)
	Swap		NYMEX	4,000		$96.07	Jan 1, 2014—Dec 31, 2014
	Swap		NYMEX	2,000		$90.08	Jan 1, 2015—Dec 31, 2015
	-1	NYMEX refers to quoted prices on the New York Mercantile Exchange
	The following tables detail the fair value of the Company's derivative instruments, including the gross amounts and adjustments made to net the derivative instruments for the presentation in the consolidated balance sheet (in thousands):
				As of September 30, 2013
	Underlying Commodity		Location on	Gross Amounts of Recognized Assets and Liabilities			Gross Amounts Offset in the Consolidated Balance Sheet			Net Amounts of Assets and Liabilities Presented in the Consolidated Balance Sheet
			Balance Sheet
	Crude oil derivative contract		Current assets	$	4,113		$	(4,113	)	$	—
	Crude oil derivative contract		Noncurrent assets	$	4,151		$	(2,676	)	$	1,475
	Crude oil derivative contract		Current liabilities	$	33,118		$	(4,113	)	$	29,005
	Crude oil derivative contract		Noncurrent liabilities	$	3,730		$	(2,676	)	$	1,054
				As of December 31, 2012
	Underlying Commodity		Location on	Gross Amounts of Recognized Assets and Liabilities			Gross Amounts Offset in the Consolidated Balance Sheet			Net Amounts of Assets and Liabilities Presented in the Consolidated Balance Sheet
			Balance Sheet
	Crude oil derivative contract		Current assets	$	16,911		$	(6,047	)	$	10,864
	Crude oil derivative contract		Noncurrent assets	$	5,455		$	(2,605	)	$	2,850
	Crude oil derivative contract		Current liabilities	$	6,352		$	(6,048	)	$	304
	Crude oil derivative contract		Noncurrent liabilities	$	6,893		$	(2,605	)	$	4,288
	The Company recognized net losses on commodity price risk management activities of $60.1 million and $53.2 million for the three and nine months ended September 30, 2013, respectively. The Company recognized a net loss on commodity price risk management activities of $31.7 million for the three months ended September 30, 2012 and a net gain on commodity price risk management activities of $40.6 million for the nine months ended September 30, 2012.

Asset_Retirement_Obligations

Asset Retirement Obligations	9 Months Ended
	Sep. 30, 2013
Asset Retirement Obligation Disclosure [Abstract]	'
Asset Retirement Obligations	'
	Asset Retirement Obligations
	The Company follows accounting for asset retirement obligations in accordance with ASC 410, Asset Retirement and Environmental Obligations, which requires that the fair value of a liability for an asset retirement obligation be recognized in the period in which it was incurred if a reasonable estimate of fair value could be made. The Company’s asset retirement obligations primarily represent the estimated present value of the amounts expected to be incurred to plug, abandon and remediate producing and shut-in wells at the end of their productive lives in accordance with applicable state and federal laws. The Company determines the estimated fair value of its asset retirement obligations by calculating the present value of estimated cash flows related to plugging and abandonment liabilities. The significant inputs used to calculate such liabilities include estimates of costs to be incurred, the Company’s credit adjusted discount rates, inflation rates and estimated dates of abandonment. The asset retirement liability is accreted to its present value each period and the capitalized asset retirement costs are depleted as a component of the full cost pool using the units-of-production method. The Company's asset retirement obligation is summarized below (in thousands):
		For the Nine Months Ended September 30, 2013			For the Year Ended December 31, 2012
	Balance beginning of period	$	9,064		$	3,627
	Liabilities incurred or acquired	4,802			4,537
	Liabilities settled	(671		)	(58		)
	Revisions in estimated cash flows	—			405
	Accretion expense	732			553
	Balance end of period	$	13,927		$	9,064

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	ASC Topic 820, Fair Value Measurement and Disclosure, establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing the asset or liability developed based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions of what market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. The hierarchy is broken down into three levels based on the reliability of the inputs as follows:
	•	Level 1: Quoted prices are available in active markets for identical assets or liabilities;
	•	Level 2: Quoted prices in active markets for similar assets and liabilities that are observable for the asset or liability;
	•	Level 3: Unobservable pricing inputs that are generally less observable from objective sources, such as discounted cash flow models or valuations.
	The financial assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the valuation of the fair value of assets and liabilities and their placement within the fair value hierarchy levels. There were no significant assets or liabilities that were measured at fair value on a non-recurring basis in periods after initial recognition.
	The Company’s non-recurring fair value measurements include asset retirement obligations, please refer to Note 7 - Asset Retirement Obligations, and the purchase price allocations for the fair value of assets and liabilities acquired through business combinations, please refer to Note 3 - Acquisitions and Divestitures.
	The Company determines the estimated fair value of its asset retirement obligations by calculating the present value of estimated cash flows related to plugging and abandonment liabilities using level 3 inputs. The significant inputs used to calculate such liabilities include estimates of costs to be incurred, the Company’s credit adjusted discount rates, inflation rates and estimated dates of abandonment. The asset retirement liability is accreted to its present value each period and the capitalized asset retirement cost is depleted as a component of the full cost pool using the units-of-production method.
	The fair value of assets and liabilities acquired through business combinations is calculated using a discounted-cash flow approach using level 3 inputs. Cash flow estimates require forecasts and assumptions for many years into the future for a variety of factors, including risk-adjusted oil and gas reserves, commodity prices and operating costs.
	The following table presents the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis as of September 30, 2013 by level within the fair value hierarchy (in thousands):
			Fair Value Measurements at September 30, 2013 Using
			Level 1		Level 2		Level 3		Total
	Financial Assets:
	Commodity price risk management asset		$	—	$	1,475	$	—	$	1,475
	Financial Liabilities:
	Commodity price risk management liability		$	—	$	30,059	$	—	$	30,059
	Commodity Derivative Instruments
	The Company determines its estimate of the fair value of derivative instruments using a market approach based on several factors, including quoted market prices in active markets, quotes from third parties, the credit rating of each counterparty, and the Company’s own credit rating. In consideration of counterparty credit risk, the Company assessed the possibility of whether each counterparty to the derivative would default by failing to make any contractually required payments. Additionally, the Company considers that it is of substantial credit quality and has the financial resources and willingness to meet its potential repayment obligations associated with the derivative transactions. At September 30, 2013 and December 31, 2012, derivative instruments utilized by the Company consist of both “no premium” collars and swaps. The crude oil derivative markets are highly active. Although the Company’s derivative instruments are valued using public indices, the instruments themselves are traded with third‑party counterparties and are not openly traded on an exchange. As such, the Company has classified these instruments as Level 2.
	Fair Value of Financial Instruments
	The Company’s financial instruments consist primarily of cash and cash equivalents, accounts receivable, accounts payable, commodity derivative instruments (discussed above) and long-term debt. The carrying values of cash and cash equivalents, accounts receivable and accounts payable are representative of their fair values due to their short-term maturities. The carrying amount of the Company’s credit facility approximated fair value as it bears interest at variable rates over the term of the loan. The fair value of the 2019 Notes, 2021 Notes and the 2022 Notes was derived from available market data. As such, the Company has classified these Senior Notes as Level 2. This disclosure (in thousands) does not impact the Company's financial position, results of operations or cash flows.
			At September 30, 2013				At December 31, 2012
			Carrying		Fair Value		Carrying		Fair Value
			Amount				Amount
	Credit facility		$	638,000	$	638,000	$	295,000	$	295,000
	2019 Notes		$	805,142	$	876,000	$	805,622	$	890,000
	2021 Notes		$	350,000	$	344,750	$	—	$	—
	2022 Notes		$	400,000	$	392,000	$	—	$	—

ShareBased_Payments

Share-Based Payments	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share-Based Payments	'
	Share Based Payments
	The Company has granted various equity-based awards to directors, officers, and employees of the Company under the 2007 Stock Incentive Plan, amended on June 3, 2010 and further amended on June 15, 2011 (as so amended, the “Plan”). The Plan authorizes the Company to issue stock options, stock appreciation rights, restricted stock and restricted stock units, performance awards, other stock grants and other stock‑based awards to any employee, consultant, independent contractor, director or officer providing services to the Company or to an affiliate of the Company. The maximum number of shares of common stock available for issuance under the Plan is equal to 14% of the Company’s issued and outstanding shares of common stock, as calculated on January 1 of each respective year, subject to adjustment as provided in the Plan. As of January 1, 2013, the maximum number of shares issuable under the Plan, including those previously issued thereunder, was approximately 37.1 million shares.
	Stock Options
	Total compensation expense related to the stock options of $2.0 million and $5.7 million was recognized for the three and nine months ended September 30, 2013, respectively, as compared to $1.7 million and $4.7 million for the three and nine months ended September 30, 2012. As of September 30, 2013, there was $8.0 million of total unrecognized compensation cost related to stock options, which is expected to be amortized over a weighted average period of 1.8 years.
	Compensation expense related to stock options is calculated using the Black Scholes‑Merton valuation model. Expected volatilities are based on the historical volatility of Kodiak’s common stock over a period consistent with that of the expected terms of the options. The expected terms of the options are estimated based on factors such as vesting periods, contractual expiration dates, historical trends in the Company’s common stock price and historical exercise behavior. The risk-free rates for periods within the contractual life of the options are based on the yields of U.S. Treasury instruments with terms comparable to the estimated option terms. The following assumptions were used for the Black‑Scholes‑Merton model to calculate the share‑based compensation expense for the period presented:
		For the Nine Months Ended September 30, 2013				For the Year Ended December 31, 2012
	Risk free rates	0.88 - 2.14%				0.78-1.48%
	Dividend yield	—		%		—		%
	Expected volatility	81.13 - 85.08%				85.23 - 90.25%
	Weighted average expected stock option life	5.78 years				5.85 years
	The weighted average fair value at the date of grant for stock options granted is as follows:
	Weighted average fair value per share	$	6.48			$	6.58
	Total options granted	1,537,400				1,159,500
	Total weighted average fair value of options granted	$	9,962,352			$	7,629,510
	A summary of the stock options outstanding is as follows:
		Number of			Weighted
		Options			Average
					Exercise
					Price
	Balance outstanding at January 1, 2013:	5,705,951			$	4.83
	Granted	1,537,400			$	9.3
	Canceled	(652,952	)		$	6.82
	Exercised	(717,244	)		$	4.33
	Balance outstanding at September 30, 2013:	5,873,155			$	5.85
	Options exercisable at September 30, 2013:	3,519,488			$	4.01
	The following table summarizes information about stock options outstanding at September 30, 2013:
		Options Outstanding							Options Exercisable
	Range of	Number of		Weighted		Weighted			Number of	Weighted	Weighted
	Exercise	Options		Average		Average			Options	Average	Average
	Prices	Outstanding		Remaining		Exercise Price			Exercisable	Remaining	Exercise Price
				Contractual						Contractual
				Life (Years)						Life (Years)
	$0.36-$2.00	738,448		2.1		$	0.91		738,448	2.1	$	0.91
	$2.01-$4.00	1,671,207		4.3		$	3.04		1,671,207	4.3	$	3.04
	$4.01-$6.00	318,000		7.6		$	5.06		174,000	7.5	$	5.1
	$6.01-$8.00	944,000		7.5		$	6.8		490,000	6.9	$	6.63
	$8.01-$10.00	1,945,000		8.9		$	9.17		439,000	8.2	$	9.5
	$10.01-$11.50	256,500		9.8		$	10.62		6,833	8.5	$	10.11
		5,873,155		6.5		$	5.85		3,519,488	4.9	$	4.01
	The aggregate intrinsic value of outstanding and vested options as of September 30, 2013 was $28.3 million based on the Company’s September 30, 2013 closing common stock price of $12.06. This amount would have been received by the option holders had all option holders exercised their options as of that date. The total grant date fair value of the shares vested during the nine months ended September 30, 2013 was $5.4 million.
	Restricted Stock Units and Restricted Stock
	Total compensation expense related to restricted stock units (“RSUs”) and restricted stock of $1.9 million and $5.4 million was recognized for the three and nine months ended September 30, 2013, respectively, as compared to $1.1 million and $3.2 million for the three and nine months ended September 30, 2012, respectively. As of September 30, 2013, there was $7.8 million of total unrecognized compensation cost related to the RSUs and restricted stock, which is expected to be amortized over a weighted average period of 2.0 years.
	As of September 30, 2013, there were 721,708 unvested performance based RSUs, 1,077,873 unvested performance based restricted stock shares and 93,500 unvested restricted stock shares with a combined weighted average grant date fair value of $8.94 per share. The total fair value vested during the nine months ended September 30, 2013 was $74,000. A summary of the RSUs and restricted stock shares outstanding is as follows:
		Number of			Weighted
		Shares			Average
					Grant Date
					Fair Value
	Non-vested restricted stock and RSU's at January 1, 2013	1,829,581			$	8.93
	Granted	71,000			$	9.18
	Forfeited	—			$	—
	Vested	(7,500	)		$	9.87
	Non-vested restricted stock and RSU's at September 30, 2013	1,893,081			$	8.94

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	Earnings Per Share
	Basic net income (loss) per share is computed by dividing net income (loss) attributable to the common stockholders by the weighted average number of common shares outstanding during the reporting period. Diluted net income per common share includes shares of restricted stock units, and the potential dilution that could occur upon exercise of options to acquire common stock computed using the treasury stock method, which assumes that the increase in the number of shares is reduced by the number of shares which could have been repurchased by the Company with the proceeds from the exercise of the options (which were assumed to have been made at the average market price of the common shares during the reporting period).
	In accordance with ASC 260-10-45, Share‑Based Payment Arrangements and Participating Securities and the Two-Class Method, the Company’s unvested restricted stock shares are deemed participating securities, since these shares would be entitled to participate in dividends declared on common shares. During periods of net income, the calculation of earnings per share for common stock exclude income attributable to the restricted stock shares from the numerator and exclude the dilutive impact of those shares from the denominator. During periods of net loss, no effect is given to the participating securities because they do not share in the losses of the Company.
	The performance based restricted stock units and unexercised stock options are not participating securities, since these shares are not entitled to participate in dividends declared on common shares. The number of potentially dilutive shares attributable to the performance based restricted stock units is based on the number of shares, if any, which would be issuable at the end of the respective reporting period, assuming that date was the end of the performance measurement period. Please refer to Note 9 - Share Based Payments under the heading Restricted Stock Units and Restricted Stock for additional discussion.
	The table below sets forth the computations of basic and diluted net income per share for the three and nine months ended September 30, 2013 and 2012 (in thousands, except per share data):
		For the Three Months Ended September 30,								For the Nine Months Ended September 30,
		2013				2012				2013			2012
	Basic net income	$	31,150			$	3,476			$	94,844		$	98,292
	Income allocable to participating securities	(4		)		(1		)		(13		)	(11		)
	Diluted net income	$	31,146			$	3,475			$	94,831		$	98,281
	Basic weighted average common shares outstanding	265,733,881				263,756,896				265,500,414			263,332,764
	Effect of dilutive securities
	Options to purchase common shares	5,616,655				5,816,540				4,546,155			5,876,540
	Assumed treasury shares purchased	(3,745,681		)		(2,612,388		)		(2,828,113		)	(2,031,462		)
	Unvested restricted stock units	961,210				442,754				773,642			354,551
	Diluted weighted average common shares outstanding	268,566,065				267,403,802				267,992,098			267,532,393
	Basic earnings per share	$	0.12			$	0.01			$	0.36		$	0.37
	Diluted earnings per share	$	0.12			$	0.01			$	0.35		$	0.37
	The following options and unvested restricted shares, which could be potentially dilutive in future periods, were not included in the computation of diluted net income per share because the effect would have been anti-dilutive for the periods indicated:
		For the Three Months Ended September 30,					For the Nine Months Ended September 30,
		2013			2012		2013		2012
	Anti-dilutive shares	256,500			647,500		1,327,000		587,500

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	Lease Obligations
	The Company leases office space in Denver, Colorado and Williston and Dickinson, North Dakota under separate operating lease agreements. The Denver, Colorado lease expires on October 31, 2016. The Williston and Dickinson, North Dakota leases expire on May 31, 2014 and December 31, 2014, respectively. Total rental commitments under non-cancelable leases for office space were $3.6 million at September 30, 2013. The future minimum lease payments under these non-cancelable leases are as follows: $295,000 in 2013, $1.2 million in 2014, $1.1 million in 2015, $1.0 million in 2016, and $0 in 2017.
	Drilling Rigs
	As of September 30, 2013, the Company was subject to commitments on three of its seven drilling rigs. One of the contracts expires in 2013, one expires in 2014 and one expires in 2015. In the event of early termination under all of these contracts, the Company would be obligated to pay an aggregate amount of approximately $24.7 million as of September 30, 2013 as required under the varying terms of such contracts.
	Pressure Pumping Services
	As of September 30, 2013, the Company was subject to a commitment with a pressure pumping service company providing 24-hour per day crew availability. In the event of early contract termination, the Company would be obligated to pay approximately $6.0 million as of September 30, 2013.
	Guarantees of the Senior Notes
	As of September 30, 2013, the Company had issued $800.0 million of 2019 Notes, $350.0 million of 2021 Notes, and $400.0 million of 2022 Notes, all of which are guaranteed on a senior unsecured basis by the Company's wholly-owned subsidiaries, Kodiak Oil & Gas (USA) Inc, Kodiak Williston, LLC and KOG Finance, LLC. Kodiak Oil & Gas Corp, as the parent company, has no independent assets or operations. The guarantees are full, unconditional and joint and several. The Company's non-guarantor subsidiary, KOG Oil & Gas, ULC has de minimis operations.
	Under the Company’s credit facility and the Indentures, the Company and subsidiary guarantors are subject to certain limitations on the ability of the subsidiary guarantors to transfer funds to the Company, including certain limitations on dividends, distributions, redemptions, payments, investments, loans and advances. There are no other restrictions on the ability of the company to obtain funds from its subsidiaries by dividend or loan (other than as described in Note 4 - Long-Term Debt). Finally, as of the most recent fiscal year end, the Company’s wholly-owned subsidiaries did not have restricted assets that exceed 25% of net assets that may not be transferred to the Company in the form of loans, advances, or cash dividends by the subsidiaries without the consent of a third-party.
	The Company may issue additional debt securities in the future that the Company's wholly‑owned subsidiaries, Kodiak Oil & Gas (USA) Inc., Kodiak Williston, LLC and KOG Finance, LLC may guarantee. Any such guarantees are expected to be full, unconditional and joint and several. As stated above, the Company has no independent assets or operations, and, other than as described herein, there are no significant restrictions on the ability of the Company to receive funds from the Company's subsidiaries through dividends, loans, and advances or otherwise.
	Other
	As is customary in the oil and gas industry, the Company may at times have commitments in place to reserve or earn certain acreage positions or wells. If the Company does not meet such commitments, the acreage positions or wells may be lost.

Basis_of_Presentation_and_Sign1

Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant inter-company balances and transactions have been eliminated in consolidation. The Company's business is transacted in US dollars and, accordingly, the financial statements are expressed in US dollars. The financial statements included herein were prepared from the records of the Company in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information and the instructions to Form 10-Q and Regulation S-X and S-K. In the opinion of management, all adjustments, consisting of normal recurring accruals that are considered necessary for a fair presentation of the interim financial information, have been included. However, operating results for the periods presented are not necessarily indicative of the results that may be expected for a full year. Kodiak's 2012 Annual Report on Form 10-K includes certain definitions and a summary of significant accounting policies and should be read in conjunction with this Form 10-Q. Except as disclosed herein, there have been no material changes to the information disclosed in the notes to the consolidated financial statements included in Kodiak's 2012 Annual Report on Form 10-K.
	The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of oil and gas reserves, 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 period. Significant areas requiring the use of assumptions, judgments and estimates include (1) oil and gas reserves; (2) cash flow estimates used in the ceiling test of oil and natural gas properties; (3) depreciation, depletion and amortization; (4) asset retirement obligations; (5) assigning fair value and allocating purchase price in connection with business combinations; (6) accrued revenue and related receivables; (7) valuation of commodity derivative instruments; (8) accrued liabilities; (9) valuation of share-based payments and (10) income taxes. Although management believes these estimates are reasonable, actual results could differ from these estimates. The Company evaluates its estimates on an on-going basis and bases its estimates on historical experience and on various other assumptions the Company believes to be reasonable under the circumstances. Although actual results may differ from these estimates under different assumptions or conditions, the Company believes that its estimates are reasonable.
Recently Issued Accounting Standards	'
	Recent Accounting Pronouncements
	In December 2011, the Financial Accounting Standards Board issued Accounting Standards Update 2011-11 (“ASU 2011-11”), Balance Sheet: 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: 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 records its derivative financial instruments on a net basis by contract. The adoption of this standard had no impact on the Company’s financial position or results of operations, but did require enhanced disclosures regarding derivative instruments. Please refer to Note 6 - Commodity Derivative Instruments for the enhanced disclosures.
	Other accounting standards that have been issued or proposed by the FASB, or other standards-setting bodies, that do not require adoption until a future date, are not expected to have a material impact on the financial statements upon adoption.

Acquisitions_and_Divestitures_1

Acquisitions and Divestitures (Tables)	9 Months Ended
	Sep. 30, 2013
Acquisitions and Divestitures [Abstract]	'
Schedule of Purchase Price Allocation [Table Text Block]	'
	The following table summarizes the preliminary purchase price and the preliminary estimated values of assets acquired and liabilities assumed (in thousands):
	Purchase Price	12-Jul-13
	Consideration Given
	Cash from credit facility	$	731,785
	Total consideration given	$	731,785
	Allocation of Purchase Price
	Proved oil and gas properties	$	393,917
	Unproved oil and gas properties	317,980
	Total fair value of oil and gas properties acquired	$	711,897
	Working capital	$	22,115
	Asset retirement obligation	(2,227		)
	Fair value of net assets acquired	$	731,785
	Working capital acquired was estimated as follows:
	Accounts receivable	$	60,418
	Accrued liabilities	(38,303		)
	Total working capital	$	22,115
Business Acquisition, Pro Forma Information [Table Text Block]	'
	The pro forma results are not necessarily indicative of what actually would have occurred if the acquisition had been completed as of the beginning of the period, nor are they necessarily indicative of future results.
		For the Three Months Ended September 30,					For the Nine Months Ended September 30,
		2013			2012		2013		2012
	Operating revenues	$	302,692		$	144,025	$	724,060	$	329,860
	Net income	$	31,935		$	11,020	$	115,225	$	105,946
	Earnings per common share
	Basic	$	0.12		$	0.04	$	0.43	$	0.4
	Diluted	$	0.12		$	0.04	$	0.43	$	0.4

LongTerm_Debt_Tables

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Schedule of long-term debt	'
	As of the dates indicated, the Company’s long-term debt consisted of the following (in thousands):
		September 30, 2013			December 31, 2012
	Credit Facility due April 2018	$	638,000		$	295,000
	2019 Notes due December 2019	800,000			800,000
	Unamortized Premium on 2019 Notes	5,142			5,622
	2021 Notes due January 2021	350,000			—
	2022 Notes due February 2022	400,000			—
	Total Long-Term Debt	$	2,193,142		$	1,100,622
	Less: Current Portion of Long-Term Debt	—			—
	Total Long-Term Debt, Net of Current Portion	$	2,193,142		$	1,100,622
Schedule of Applicable Margin options depending on the applicable Borrowing Base Utilization Percentage	'
	The grid below shows the Applicable Margin options depending on the applicable Borrowing Base Utilization Percentage (as defined in the credit facility) as of the date of this filing:
	Borrowing Base Utilization Grid
	Borrowing Base Utilization Percentage	<25.0%		>25.0% <50.0%			>50.0% <75.0%		>75.0% <90.0%		>90.0%
	Eurodollar Loans	1.5	%	1.75	%		2	%	2.25	%	2.5	%
	ABR Loans	0.5	%	0.75	%		1	%	1.25	%	1.5	%
	Commitment Fee Rate	0.375	%	0.375	%		0.5	%	0.5	%	0.5	%

Commodity_Derivative_Instrumen1

Commodity Derivative Instruments (Tables)	9 Months Ended										1 Months Ended
	Sep. 30, 2013										Oct. 31, 2013
											Subsequent Event [Member]
Commodity Derivative Instrument	'										'
Schedule of the Company's commodity derivative contracts	'										'
	The Company’s commodity derivative contracts as of September 30, 2013 are summarized below:										Subsequent to September 30, 2013, the Company entered into additional commodity derivative contracts as summarized below:
	Collars	Basis(1)	Quantity (Bbl/d)		Strike Price						Contract Type		Basis (1)	Average Quantity (Bbl/d)	Average Swap Price	Term
					($/Bbl)										($/Bbl)
	Oct 1, 2013—Dec 31, 2013	NYMEX	500		$85.00 - $117.00						Swap		NYMEX	4,000	$96.07	Jan 1, 2014—Dec 31, 2014
	Oct 1, 2013—Dec 31, 2015	NYMEX	300 - 425		$85.00 - $102.75						Swap		NYMEX	2,000	$90.08	Jan 1, 2015—Dec 31, 2015
	Swaps	Basis (1)	Average Quantity (Bbl/d)		Average Swap Price						-1	NYMEX refers to quoted prices on the New York Mercantile Exchange
					($/Bbl)
	Oct 1, 2013—Dec 31, 2013	NYMEX	22,105		$96.82
	2014 Total	NYMEX	19,800		$92.73
	2015 Total	NYMEX	1,625		$87.13
Schedule of fair values of the derivatives recorded in the applicable condensed consolidated balance sheet, by category	'										'
	The following tables detail the fair value of the Company's derivative instruments, including the gross amounts and adjustments made to net the derivative instruments for the presentation in the consolidated balance sheet (in thousands):
			As of September 30, 2013
	Underlying Commodity	Location on	Gross Amounts of Recognized Assets and Liabilities			Gross Amounts Offset in the Consolidated Balance Sheet			Net Amounts of Assets and Liabilities Presented in the Consolidated Balance Sheet
		Balance Sheet
	Crude oil derivative contract	Current assets	$	4,113		$	(4,113	)	$	—
	Crude oil derivative contract	Noncurrent assets	$	4,151		$	(2,676	)	$	1,475
	Crude oil derivative contract	Current liabilities	$	33,118		$	(4,113	)	$	29,005
	Crude oil derivative contract	Noncurrent liabilities	$	3,730		$	(2,676	)	$	1,054
			As of December 31, 2012
	Underlying Commodity	Location on	Gross Amounts of Recognized Assets and Liabilities			Gross Amounts Offset in the Consolidated Balance Sheet			Net Amounts of Assets and Liabilities Presented in the Consolidated Balance Sheet
		Balance Sheet
	Crude oil derivative contract	Current assets	$	16,911		$	(6,047	)	$	10,864
	Crude oil derivative contract	Noncurrent assets	$	5,455		$	(2,605	)	$	2,850
	Crude oil derivative contract	Current liabilities	$	6,352		$	(6,048	)	$	304
	Crude oil derivative contract	Noncurrent liabilities	$	6,893		$	(2,605	)	$	4,288

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	9 Months Ended
	Sep. 30, 2013
Asset Retirement Obligation Disclosure [Abstract]	'
Schedule of activities of the Company's asset retirement obligation	'
	The Company's asset retirement obligation is summarized below (in thousands):
		For the Nine Months Ended September 30, 2013			For the Year Ended December 31, 2012
	Balance beginning of period	$	9,064		$	3,627
	Liabilities incurred or acquired	4,802			4,537
	Liabilities settled	(671		)	(58		)
	Revisions in estimated cash flows	—			405
	Accretion expense	732			553
	Balance end of period	$	13,927		$	9,064

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Schedule of the Company's financial assets and liabilities that were accounted for at fair value on a recurring basis	'
	The following table presents the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis as of September 30, 2013 by level within the fair value hierarchy (in thousands):
		Fair Value Measurements at September 30, 2013 Using
		Level 1		Level 2		Level 3		Total
	Financial Assets:
	Commodity price risk management asset	$	—	$	1,475	$	—	$	1,475
	Financial Liabilities:
	Commodity price risk management liability	$	—	$	30,059	$	—	$	30,059
Schedule of fair value of financial instruments	'
	This disclosure (in thousands) does not impact the Company's financial position, results of operations or cash flows.
		At September 30, 2013				At December 31, 2012
		Carrying		Fair Value		Carrying		Fair Value
		Amount				Amount
	Credit facility	$	638,000	$	638,000	$	295,000	$	295,000
	2019 Notes	$	805,142	$	876,000	$	805,622	$	890,000
	2021 Notes	$	350,000	$	344,750	$	—	$	—
	2022 Notes	$	400,000	$	392,000	$	—	$	—

ShareBased_Payments_Tables

Share-Based Payments (Tables)	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule of assumptions used for the Black-Scholes-Merton model to calculate the share-based compensation expense for the periods	'
	The following assumptions were used for the Black‑Scholes‑Merton model to calculate the share‑based compensation expense for the period presented:
		For the Nine Months Ended September 30, 2013				For the Year Ended December 31, 2012
	Risk free rates	0.88 - 2.14%				0.78-1.48%
	Dividend yield	—		%		—		%
	Expected volatility	81.13 - 85.08%				85.23 - 90.25%
	Weighted average expected stock option life	5.78 years				5.85 years
	The weighted average fair value at the date of grant for stock options granted is as follows:
	Weighted average fair value per share	$	6.48			$	6.58
	Total options granted	1,537,400				1,159,500
	Total weighted average fair value of options granted	$	9,962,352			$	7,629,510
Summary of the stock options outstanding	'
	A summary of the stock options outstanding is as follows:
		Number of			Weighted
		Options			Average
					Exercise
					Price
	Balance outstanding at January 1, 2013:	5,705,951			$	4.83
	Granted	1,537,400			$	9.3
	Canceled	(652,952	)		$	6.82
	Exercised	(717,244	)		$	4.33
	Balance outstanding at September 30, 2013:	5,873,155			$	5.85
	Options exercisable at September 30, 2013:	3,519,488			$	4.01
Schedule of stock options outstanding, by exercise price range	'
	The following table summarizes information about stock options outstanding at September 30, 2013:
		Options Outstanding							Options Exercisable
	Range of	Number of		Weighted		Weighted			Number of	Weighted	Weighted
	Exercise	Options		Average		Average			Options	Average	Average
	Prices	Outstanding		Remaining		Exercise Price			Exercisable	Remaining	Exercise Price
				Contractual						Contractual
				Life (Years)						Life (Years)
	$0.36-$2.00	738,448		2.1		$	0.91		738,448	2.1	$	0.91
	$2.01-$4.00	1,671,207		4.3		$	3.04		1,671,207	4.3	$	3.04
	$4.01-$6.00	318,000		7.6		$	5.06		174,000	7.5	$	5.1
	$6.01-$8.00	944,000		7.5		$	6.8		490,000	6.9	$	6.63
	$8.01-$10.00	1,945,000		8.9		$	9.17		439,000	8.2	$	9.5
	$10.01-$11.50	256,500		9.8		$	10.62		6,833	8.5	$	10.11
		5,873,155		6.5		$	5.85		3,519,488	4.9	$	4.01
Summary of the RSUs and restricted stock shares outstanding	'
	A summary of the RSUs and restricted stock shares outstanding is as follows:
		Number of			Weighted
		Shares			Average
					Grant Date
					Fair Value
	Non-vested restricted stock and RSU's at January 1, 2013	1,829,581			$	8.93
	Granted	71,000			$	9.18
	Forfeited	—			$	—
	Vested	(7,500	)		$	9.87
	Non-vested restricted stock and RSU's at September 30, 2013	1,893,081			$	8.94

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Schedule of computations of basic and diluted net income per share	'
	The table below sets forth the computations of basic and diluted net income per share for the three and nine months ended September 30, 2013 and 2012 (in thousands, except per share data):
		For the Three Months Ended September 30,								For the Nine Months Ended September 30,
		2013				2012				2013			2012
	Basic net income	$	31,150			$	3,476			$	94,844		$	98,292
	Income allocable to participating securities	(4		)		(1		)		(13		)	(11		)
	Diluted net income	$	31,146			$	3,475			$	94,831		$	98,281
	Basic weighted average common shares outstanding	265,733,881				263,756,896				265,500,414			263,332,764
	Effect of dilutive securities
	Options to purchase common shares	5,616,655				5,816,540				4,546,155			5,876,540
	Assumed treasury shares purchased	(3,745,681		)		(2,612,388		)		(2,828,113		)	(2,031,462		)
	Unvested restricted stock units	961,210				442,754				773,642			354,551
	Diluted weighted average common shares outstanding	268,566,065				267,403,802				267,992,098			267,532,393
	Basic earnings per share	$	0.12			$	0.01			$	0.36		$	0.37
	Diluted earnings per share	$	0.12			$	0.01			$	0.35		$	0.37
Schedule of options and unvested restricted shares, which could be potentially dilutive in future periods, not included in the computation of diluted net income per share	'
	The following options and unvested restricted shares, which could be potentially dilutive in future periods, were not included in the computation of diluted net income per share because the effect would have been anti-dilutive for the periods indicated:
		For the Three Months Ended September 30,					For the Nine Months Ended September 30,
		2013			2012		2013		2012
	Anti-dilutive shares	256,500			647,500		1,327,000		587,500

Acquisitions_and_Divestitures_2

Acquisitions and Divestitures (Details) (USD $)

3 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Jul. 12, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2013

Properties Acquired in July 2013 [Member]

Properties Acquired in July 2013 [Member]

Series of Individually Immaterial Business Acquisitions [Member]

Series of Individually Immaterial Business Acquisitions [Member]

Series of Individually Immaterial Business Acquisitions [Member]

Series of Individually Immaterial Business Acquisitions [Member]

General and Administrative Expenses [Member]

Subsequent Event [Member]

acre

acre

Properties Acquired in July 2013 [Member]

General and Administrative Expenses [Member]

Properties Acquired in July 2013 [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Gas and Oil Acreage Acquired

'

'

'

'

42,000

'

'

'

'

'

'

'

Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual

'

'

'

'

'

$40,400,000

$0

$0

$0

$0

'

'

Business Combination, Acquisition Related Costs

'

'

'

'

'

'

'

'

'

'

185,000

20,000

Cash from credit facility

'

'

'

'

731,785,000

'

'

'

'

'

'

'

Total consideration given

'

'

'

'

731,785,000

'

'

'

'

'

'

'

Proved oil and gas properties

'

'

'

'

393,917,000

'

41,800,000

'

41,800,000

'

'

'

Unproved oil and gas properties

'

'

'

'

317,980,000

'

4,100,000

'

4,100,000

'

'

'

Total fair value of oil and gas properties acquired

'

'

'

'

711,897,000

'

'

'

'

'

'

'

Working capital

'

'

'

'

22,115,000

'

'

'

'

'

'

'

Asset retirement obligation

'

'

'

'

2,227,000

'

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets

'

'

'

'

731,785,000

'

'

'

'

'

'

'

Accounts receivable

'

'

'

'

60,418,000

'

'

'

'

'

'

'

Accrued liabilities

'

'

'

'

-38,303,000

'

'

'

'

'

'

'

Business Acquisitions, Pro Forma Effect of Adjustment for Depletion Depreciation Amortization and Accretion Expense

1,000,000

9,300,000

23,500,000

14,200,000

'

'

'

'

'

'

'

'

Business Acquisitions, Pro Forma Effect of Adjustment for Amortization of Financing Costs

26,000

204,000

434,000

612,000

'

'

'

'

'

'

'

'

Business Acquisitions, Pro Forma Effect of Incremental Interest Expense on Acquisition Financing

600,000

3,900,000

5,500,000

13,800,000

'

'

'

'

'

'

'

'

Business Acquisitions, Pro Forma Capitalized Interest

9,700,000

11,900,000

29,900,000

35,700,000

'

'

'

'

'

'

'

'

Business Acquisitions, Pro Forma Effect of Adjustment for Income Tax Expense

480,000

4,600,000

12,500,000

4,700,000

'

'

'

'

'

'

'

'

Business Acquisition, Pro Forma Revenue

302,692,000

144,025,000

724,060,000

329,860,000

'

'

'

'

'

'

'

'

Business Acquisition, Pro Forma Net Income (Loss)

31,935,000

11,020,000

115,225,000

105,946,000

'

'

'

'

'

'

'

'

Business Acquisition, Pro Forma Earnings Per Share, Basic

$0.12

$0.04

$0.43

$0.40

'

'

'

'

'

'

'

'

Business Acquisition, Pro Forma Earnings Per Share, Diluted

$0.12

$0.04

$0.43

$0.40

'

'

'

'

'

'

'

'

Gas and Oil Acreage Divested

'

'

'

'

'

'

3,700

'

'

'

'

'

Business Acquisition, Cost of Acquired Entity, Purchase Price

'

'

'

'

'

'

$36,700,000

'

'

'

'

'

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

9 Months Ended

1 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

31-May-12

Sep. 30, 2013

Dec. 31, 2012

17-May-12

Nov. 30, 2011

Jan. 31, 2013

Sep. 30, 2013

Dec. 31, 2012

Jul. 31, 2013

Sep. 30, 2013

Jul. 26, 2013

Dec. 31, 2012

Sep. 30, 2013

Jan. 10, 2012

Sep. 30, 2013

Oct. 30, 2013

Jul. 12, 2013

Sep. 30, 2013

Oct. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Apr. 03, 2013

Sep. 30, 2013

Apr. 03, 2013

Jan. 31, 2012

Credit Facility due April 2018

Credit Facility due April 2018

8.125% Senior Notes due December 2019

8.125% Senior Notes due December 2019

8.125% Senior Notes due December 2019

8.125% Senior Notes due December 2019

8.125% Senior Notes due December 2019

5.50% Senior Notes due January 2021

5.50% Senior Notes due January 2021

5.50% Senior Notes due January 2021

5.50% Senior Notes due February 2022 [Member]

5.50% Senior Notes due February 2022 [Member]

5.50% Senior Notes due February 2022 [Member]

5.50% Senior Notes due February 2022 [Member]

Senior Notes [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsequent Event [Member]

Debt Instrument, Borrowing Base Utilization Greater than Equal to 25 Percent and Less than 50 Percent [Member]

Debt Instrument, Borrowing Base Utilization Greater than Equal to 25 Percent and Less than 50 Percent [Member]

Debt Instrument, Borrowing Base Utilization Greater than Equal to 25 Percent and Less than 50 Percent [Member]

Debt Instrument, Borrowing Base Utilization Greater than Equal to 25 Percent and Less than 50 Percent [Member]

Debt Instrument, Borrowing Base Utilization Greater than Equal to 25 Percent and Less than 50 Percent [Member]

Debt Instrument Borrowing Base Utilization Greater than Equal to 50 Percent and Less than 75 Percent [Member]

Debt Instrument Borrowing Base Utilization Greater than Equal to 50 Percent and Less than 75 Percent [Member]

Debt Instrument Borrowing Base Utilization Greater than Equal to 50 Percent and Less than 75 Percent [Member]

Debt Instrument Borrowing Base Utilization Greater than Equal to 50 Percent and Less than 75 Percent [Member]

Debt Instrument Borrowing Base Utilization Greater than Equal to 50 Percent and Less than 75 Percent [Member]

Debt Instrument Borrowing Base Utilization Greater than Equal to 75 Percent and Less than 90 Percent [Member]

Debt Instrument Borrowing Base Utilization Greater than Equal to 75 Percent and Less than 90 Percent [Member]

Debt Instrument Borrowing Base Utilization Greater than Equal to 75 Percent and Less than 90 Percent [Member]

Debt Instrument Borrowing Base Utilization Greater than Equal to 75 Percent and Less than 90 Percent [Member]

Debt Instrument Borrowing Base Utilization Greater than Equal to 75 Percent and Less than 90 Percent [Member]

Debt Instrument, Borrowing Base Utilization Greater than 90 Percent [Member]

Debt Instrument, Borrowing Base Utilization Greater than 90 Percent [Member]

Debt Instrument, Borrowing Base Utilization Greater than 90 Percent [Member]

Debt Instrument, Borrowing Base Utilization Greater than 90 Percent [Member]

Debt Instrument Borrowing Base Utilization Less than 25 Percent [Member]

Debt Instrument Borrowing Base Utilization Less than 25 Percent [Member]

Debt Instrument Borrowing Base Utilization Less than 25 Percent [Member]

Debt Instrument Borrowing Base Utilization Less than 25 Percent [Member]

Debt Instrument Borrowing Base Utilization Less than 25 Percent [Member]

Debt Instrument Borrowing Base Utilization Less than 25 Percent [Member]

Interest Income [Member]

Second Lien Credit Agreement due April 2017

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Subsidiaries [Member]

Maximum [Member]

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Credit Facility due April 2018

Second Lien Credit Agreement due April 2017

Minimum

Maximum [Member]

LIBO rate

Alternate base rate

Minimum

Maximum [Member]

LIBO rate

Alternate base rate

Minimum

Maximum [Member]

LIBO rate

Alternate base rate

Minimum

LIBO rate

Alternate base rate

Maximum [Member]

LIBO rate

LIBO rate

Alternate base rate

Alternate base rate

Long-Term Debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt

$2,193,142,000

'

$2,193,142,000

'

$1,100,622,000

$638,000,000

$295,000,000

'

$800,000,000

$800,000,000

'

'

'

$350,000,000

$0

'

$400,000,000

'

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt, Current Maturities

0

'

0

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unamortized Premium on 8.125% Senior Notes

'

'

'

'

'

'

'

'

5,142,000

5,622,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total Long-Term Debt, Net of Current Portion

2,193,142,000

'

2,193,142,000

'

1,100,622,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum credit amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Current Borrowing Capacity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility Current Borrowing Capacity Company Election Lender Aggregate Commitment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of times the Company may elect a redetermination of the borrowing base during any six month period

1

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Spread on variable rate, additional margin or Applicable Margin (as a percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.75%

0.75%

'

'

'

2.00%

1.00%

'

'

'

2.25%

1.25%

'

'

2.50%

1.50%

'

'

1.50%

'

0.50%

'

'

Commitment fee rate (as a percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.50%

'

0.38%

'

'

'

'

0.50%

'

'

'

'

0.50%

'

'

'

'

0.50%

'

'

'

0.38%

'

'

'

'

'

'

DebtInstrumentDecreaseOfBasisSpreadOnVariableRate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.25%

'

0.25%

'

Borrowing base utilization percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

25.00%

50.00%

'

'

'

50.00%

75.00%

'

'

'

75.00%

90.00%

'

'

'

90.00%

'

'

'

25.00%

'

'

'

'

'

Minimum current ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum ratio of total debt to EBITDAX

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding borrowings under the credit facility

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

638,000,000

678,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Available credit

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

462,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Increase (Decrease), Net

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

40,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Early repayment of debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Prepayment penalty

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,000,000

Principal amount of senior notes issued

'

'

'

'

'

'

'

'

800,000,000

'

150,000,000

650,000,000

350,000,000

350,000,000

'

'

400,000,000

400,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate, stated percentage

'

'

'

'

'

'

'

'

8.13%

'

'

'

'

5.50%

'

'

5.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of principal amount at which the entity issued notes

'

'

'

'

'

'

'

104.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net proceeds from issuance of notes after deducting discounts and fees

'

'

'

'

'

'

'

784,200,000

'

'

'

'

343,100,000

'

'

391,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum percentage of the aggregate principal amount entitled to be redeemed before December 2014

'

'

'

'

'

'

'

'

35.00%

'

'

'

'

35.00%

'

'

35.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Redemption Price as Percentage of Principal Amount

'

'

'

'

'

'

'

'

108.13%

'

'

'

'

105.50%

'

'

105.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Redemption Price due to Change of Control as Percentage of Principal Amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

101.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred Financing Costs

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred financing costs recorded related to credit facility and senior notes

42,100,000

'

42,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of deferred financing costs

1,400,000

794,000

3,500,000

2,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest Incurred On Long-Term Debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest expense

29,500,000

17,000,000

73,300,000

45,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Capitalized interest costs

9,700,000

11,200,000

25,600,000

35,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of bond premium

($163,000)

($151,000)

($480,000)

($224,000)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Tax Disclosure [Abstract]	'	'	'	'
Effective Income Tax Rate Continuing Operations	'	'	38.10%	18.26%
Income tax expense (benefit)	$19,500	($3,980)	$58,400	$21,940
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	'	'	35.00%	35.00%

Commodity_Derivative_Instrumen2

Commodity Derivative Instruments (Details) (USD $)

9 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Oct. 30, 2013

Sep. 30, 2013

Oct. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

counterparty

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Commodity derivative contract

Current Assets [Member]

Current Assets [Member]

Noncurrent Assets [Member]

Noncurrent Assets [Member]

Current Liabilities [Member]

Current Liabilities [Member]

Noncurrent Liabilities [Member]

Noncurrent Liabilities [Member]

Oct 1, 2013-December31, 2013

2014

2014

2015

2015

Collar One [Member]

Collar Two [Member]

Collar Three [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Derivative Instruments and Hedging Activities Disclosure [Abstract]

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Number of counterparties

9

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'

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'

'

'

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'

'

'

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'

'

'

Number of defaulting parties to the agreement needed to allow a non-defaulting party to terminate a derivative contract

1

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'

'

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'

'

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Commodity Derivative Instrument

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative Asset, Fair Value, Gross Asset

'

$4,113

$16,911

$4,151

$5,455

'

'

'

'

'

'

'

'

'

'

'

'

Derivative Asset, Fair Value, Gross Liability

'

-4,113

-6,047

-2,676

-2,605

'

'

'

'

'

'

'

'

'

'

'

'

Derivative Asset, Fair Value, Net

'

0

10,864

1,475

2,850

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'

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'

'

'

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'

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'

Derivative Liability, Fair Value, Gross Liability

'

'

'

'

'

33,118

6,352

3,730

6,893

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'

'

'

'

'

'

'

Derivative Liability, Fair Value, Gross Asset

'

'

'

'

'

-4,113

-6,048

-2,676

-2,605

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'

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Derivative Liability, Fair Value, Net

'

'

'

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$29,005

$304

$1,054

$4,288

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Strike Price ($/Bbl), Floor

'

'

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85

'

85

Strike Price ($/Bbl), Cap

'

'

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117

'

102.75

Derivative, Nonmonetary Notional Amount

'

'

'

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'

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22,105

19,800

4,000

1,625

2,000

500

300

425

Average Swap Price ($/Bbl)

'

'

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96.82

92.73

96.07

87.13

90.08

'

'

'

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Summary of activities of the Company's asset retirement obligation	'	'
Balance beginning of period	$9,064	$3,627
Liabilities incurred or acquired	4,802	4,537
Liabilities settled	-671	-58
Revisions in estimated cash flows	0	405
Accretion expense	732	553
Balance end of period	$13,927	$9,064

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (Recurring basis, USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Level 1	'
Financial Assets:	'
Commodity price risk management asset	$0
Financial Liabilities:	'
Commodity price risk management liability	0
Level 2	'
Financial Assets:	'
Commodity price risk management asset	1,475
Financial Liabilities:	'
Commodity price risk management liability	30,059
Level 3	'
Financial Assets:	'
Commodity price risk management asset	0
Financial Liabilities:	'
Commodity price risk management liability	0
Total	'
Financial Assets:	'
Commodity price risk management asset	1,475
Financial Liabilities:	'
Commodity price risk management liability	$30,059

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value of Financial Instruments	'	'
Credit facilities	$638,000	$295,000
Senior notes	1,555,142	805,622
Carrying Amount | Credit Facility due April 2018	'	'
Fair Value of Financial Instruments	'	'
Credit facilities	638,000	295,000
Carrying Amount | 8.125% Senior Notes due December 2019	'	'
Fair Value of Financial Instruments	'	'
Senior notes	805,142	805,622
Carrying Amount | 5.50% Senior Notes due January 2021	'	'
Fair Value of Financial Instruments	'	'
Senior notes	350,000	0
Fair Value | Credit Facility due April 2018	'	'
Fair Value of Financial Instruments	'	'
Credit facilities	638,000	295,000
Fair Value | 8.125% Senior Notes due December 2019	'	'
Fair Value of Financial Instruments	'	'
Senior notes	876,000	890,000
Fair Value | 5.50% Senior Notes due January 2021	'	'
Fair Value of Financial Instruments	'	'
Senior notes	$344,750,000	$0

ShareBased_Payments_Details

Share-Based Payments (Details) (Stock Incentive 2007 Plan [Member], Employee Stock Option [Member], USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Compensation Plan	'	'	'	'	'
Stock Granted, Value, Share-based Compensation, Gross	'	'	$9,962,352	'	$7,629,510
Aggregate intrinsic value of both outstanding and vested options (in dollars)	28,300,000	'	28,300,000	'	'
Number of shares of common stock available for issuance under the plan as a percentage of the company's issued and outstanding shares of common stock	14.00%	'	14.00%	'	'
Maximum number of shares issuable under the Plan, including those previously issued there under	'	'	'	'	37,100,000
Total compensation expense recognized (in dollars)	2,000,000	1,700,000	5,700,000	4,700,000	'
Total unrecognized compensation cost (in dollars)	8,000,000	'	8,000,000	'	'
Expected amortization period for total unrecognized compensation cost	'	'	'1 year 9 months 15 days	'	'
Assumptions used for the Black-Scholes-Merton model to calculate the share-based compensation expense for the period	'	'	'	'	'
Risk free rates, minimum (as a percent)	'	'	0.88%	'	77.64%
Risk free rates, maximum (as a percent)	'	'	2.14%	'	1.48%
Dividend yield (as a percent)	'	'	0.00%	'	0.00%
Expected volatility, minimum (as a percent)	'	'	81.13%	'	85.23%
Expected volatility, maximum (as a percent)	'	'	85.08%	'	90.25%
Weighted average expected stock option life	'	'	'5 years 9 months 11 days	'	'5 years 10 months 6 days
Additional general disclosures	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	'	'	$6.48	'	$6.58
Total options granted (in shares)	'	'	1,537,400	'	1,159,500
Number of Options	'	'	'	'	'
Balance outstanding at the beginning of the period (in shares)	'	'	5,705,951	'	'
Granted (in shares)	'	'	1,537,400	'	1,159,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	'	'	-652,952	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	'	'	-717,244	'	'
Balance outstanding at the end of the period (in shares)	5,873,155	'	5,873,155	'	5,705,951
Options exercisable (in shares)	3,519,488	'	3,519,488	'	'
Weighted Average Exercise Price	'	'	'	'	'
Balance outstanding at the beginning of the period (in dollars per share)	'	'	$4.83	'	'
Granted (in dollars per share)	'	'	$9.30	'	'
Canceled (in dollars per share)	'	'	$6.82	'	'
Exercised (in dollars per share)	'	'	$4.33	'	'
Balance outstanding at the end of the period (in dollars per share)	$5.85	'	$5.85	'	$4.83
Options exercisable (in dollars per share)	$4.01	'	$4.01	'	'
Common Stock Market Price Per Share	$12.06	'	$12.06	'	'
Total grant date fair value of the shares vested (in dollars)	$5,400,000	'	$5,400,000	'	'
Exercise Price Range, One [Member]	'	'	'	'	'
Compensation Plan	'	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	'	'	$0.36	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	'	'	$2	'	'
Exercise Price Range, Two [Member]	'	'	'	'	'
Compensation Plan	'	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	'	'	$2.01	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	'	'	$4	'	'
Exercise Price Range, Three [Member]	'	'	'	'	'
Compensation Plan	'	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	'	'	$4.01	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	'	'	$6	'	'
Exercise Price Range, Four [Member]	'	'	'	'	'
Compensation Plan	'	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	'	'	$6.01	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	'	'	$8	'	'
Exercise Price Range, Five [Member]	'	'	'	'	'
Compensation Plan	'	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	'	'	$8.01	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	'	'	$10	'	'
Exercise Price Range, Six [Member]	'	'	'	'	'
Compensation Plan	'	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	'	'	$10.01	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	'	'	$11.50	'	'

ShareBased_Payments_Details_2

Share-Based Payments (Details 2) (Stock Incentive 2007 Plan [Member], Employee Stock Option [Member], USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Compensation Plan	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$6.48	$6.58
Number of Options Outstanding (in shares)	5,873,155	'
Weighted Average Remaining Contractual Life	'6 years 6 months 0 days	'
Weighted Average Exercise Price (in dollars per share)	$5.85	'
Number of Options Exercisable (in shares)	3,519,488	'
Weighted Average Remaining Contractual Life	'4 years 10 months 13 days	'
Weighted Average Exercise Price (in dollars per share)	$4.01	'
Exercise Price Range, One [Member]	'	'
Compensation Plan	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$0.36	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$2	'
Number of Options Outstanding (in shares)	738,448	'
Weighted Average Remaining Contractual Life	'2 years 1 month 13 days	'
Weighted Average Exercise Price (in dollars per share)	$0.91	'
Number of Options Exercisable (in shares)	738,448	'
Weighted Average Remaining Contractual Life	'2 years 1 month 13 days	'
Weighted Average Exercise Price (in dollars per share)	$0.91	'
Exercise Price Range, Two [Member]	'	'
Compensation Plan	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$2.01	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$4	'
Number of Options Outstanding (in shares)	1,671,207	'
Weighted Average Remaining Contractual Life	'4 years 3 months 21 days	'
Weighted Average Exercise Price (in dollars per share)	$3.04	'
Number of Options Exercisable (in shares)	1,671,207	'
Weighted Average Remaining Contractual Life	'4 years 3 months 21 days	'
Weighted Average Exercise Price (in dollars per share)	$3.04	'
Exercise Price Range, Three [Member]	'	'
Compensation Plan	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$4.01	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$6	'
Number of Options Outstanding (in shares)	318,000	'
Weighted Average Remaining Contractual Life	'7 years 7 months 3 days	'
Weighted Average Exercise Price (in dollars per share)	$5.06	'
Number of Options Exercisable (in shares)	174,000	'
Weighted Average Remaining Contractual Life	'7 years 6 months 8 days	'
Weighted Average Exercise Price (in dollars per share)	$5.10	'
Exercise Price Range, Four [Member]	'	'
Compensation Plan	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$6.01	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$8	'
Number of Options Outstanding (in shares)	944,000	'
Weighted Average Remaining Contractual Life	'7 years 6 months 1 day	'
Weighted Average Exercise Price (in dollars per share)	$6.80	'
Number of Options Exercisable (in shares)	490,000	'
Weighted Average Remaining Contractual Life	'6 years 11 months 8 days	'
Weighted Average Exercise Price (in dollars per share)	$6.63	'
Exercise Price Range, Five [Member]	'	'
Compensation Plan	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$8.01	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$10	'
Number of Options Outstanding (in shares)	1,945,000	'
Weighted Average Remaining Contractual Life	'8 years 11 months 4 days	'
Weighted Average Exercise Price (in dollars per share)	$9.17	'
Number of Options Exercisable (in shares)	439,000	'
Weighted Average Remaining Contractual Life	'8 years 2 months 19 days	'
Weighted Average Exercise Price (in dollars per share)	$9.50	'
Exercise Price Range, Six [Member]	'	'
Compensation Plan	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$10.01	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$11.50	'
Number of Options Outstanding (in shares)	256,500	'
Weighted Average Remaining Contractual Life	'9 years 9 months 23 days	'
Weighted Average Exercise Price (in dollars per share)	$10.62	'
Number of Options Exercisable (in shares)	6,833	'
Weighted Average Remaining Contractual Life	'8 years 6 months 0 days	'
Weighted Average Exercise Price (in dollars per share)	$10.11	'

ShareBased_Payments_Details_3

Share-Based Payments (Details 3) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2013
Restricted Stock and Restricted Stock Units [Member]	'	'	'	'	'
Number of Shares	'	'	'	'	'
Non-vested awards at beginning of the period (in shares)	'	'	1,829,581	'	'
Granted (in shares)	'	'	71,000	'	'
Forfeited (in shares)	'	'	0	'	'
Vested (in shares)	'	'	-7,500	'	'
Non-vested awards at the end of the period (in shares)	1,893,081	'	1,893,081	'	'
Weighted Average Grant Date Fair Value	'	'	'	'	'
Non-vested awards at beginning of the period (in dollars per share)	'	'	$8.93	'	'
Granted (in dollars per share)	'	'	$9.18	'	'
Vested (in dollars per share)	'	'	$9.87	'	'
Non-vested awards at the end of the period (in dollars per share)	$8.94	'	$8.94	'	'
Restricted Stock Shares, Restricted Stock Units, Restricted Performance Shares [Member]	'	'	'	'	'
Compensation Plan	'	'	'	'	'
Total compensation expense recognized (in dollars)	$1,900,000	$1,100,000	$5,400,000	$3,200,000	'
Total unrecognized compensation cost (in dollars)	7,800,000	'	7,800,000	'	'
Expected amortization period for total unrecognized compensation cost	'	'	'1 year 11 months 15 days	'	'
Total fair value vested (in dollars)	'	'	$74,000	'	'
Weighted Average Grant Date Fair Value	'	'	'	'	'
Non-vested awards at beginning of the period (in dollars per share)	'	'	'	'	$8.94
Forfeited (in dollars per share)	'	'	$0	'	'
Non-vested awards at the end of the period (in dollars per share)	'	'	'	'	$8.94
Restricted Performance Shares [Domain]	'	'	'	'	'
Number of Shares	'	'	'	'	'
Non-vested awards at the end of the period (in shares)	1,077,873	'	1,077,873	'	'
Restricted Stock [Member]	'	'	'	'	'
Number of Shares	'	'	'	'	'
Non-vested awards at the end of the period (in shares)	93,500	'	93,500	'	'
Restricted Stock Units (RSUs) [Member]	'	'	'	'	'
Number of Shares	'	'	'	'	'
Non-vested awards at the end of the period (in shares)	721,708	'	721,708	'	'

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Computations of basic and diluted net income per share	'	'	'	'
Basic net income	$31,150	$3,476	$94,844	$98,292
Income allocable to participating securities	-4	-1	-13	-11
Diluted net income	$31,146	$3,475	$94,831	$98,281
Basic weighted average common shares outstanding	265,733,881	263,756,896	265,500,414	263,332,764
Effect of dilutive securities due to options to purchase common shares (in shares)	5,616,655	5,816,540	4,546,155	5,876,540
Effect of dilutive securities due to assumed treasury shares purchased (in shares)	-3,745,681	-2,612,388	-2,828,113	-2,031,462
Effect of dilutive securities due to unvested restricted stock units (in shares)	961,210	442,754	773,642	354,551
Diluted weighted average common shares outstanding	268,566,065	267,403,802	267,992,098	267,532,393
Basic earnings per share	$0.12	$0.01	$0.36	$0.37
Diluted earnings per share	$0.12	$0.01	$0.35	$0.37
Potentially dilutive securities not included in computation of diluted income per share	'	'	'	'
Anti-dilutive shares	256,500	647,500	1,327,000	587,500

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	9 Months Ended										9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	17-May-12	Nov. 30, 2011	Sep. 30, 2013	Jan. 31, 2013	Sep. 30, 2013	Jul. 26, 2013	Sep. 30, 2013
	drilling_rigs	Termination of Drilling Rig Contract [Member]	Termination of Pressure Pumping Services Contract [Member]	8.125% Senior Notes due December 2019	8.125% Senior Notes due December 2019	8.125% Senior Notes due December 2019	5.50% Senior Notes due January 2021	5.50% Senior Notes due January 2021	5.50% Senior Notes due February 2022 [Member]	5.50% Senior Notes due February 2022 [Member]	Subsidiaries [Member]
	Contracts										Maximum [Member]
Commitments and Contingencies	'	'	'	'	'	'	'	'	'	'	'
Pressure Pumping Crew Availability Per Day	'1 day	'	'	'	'	'	'	'	'	'	'
Number of Drilling Rig Contracts	3	'	'	'	'	'	'	'	'	'	'
Number of Drilling Rigs, Total	7	'	'	'	'	'	'	'	'	'	'
Number of Drilling Rig Contracts Expiring for Next Fiscal Year	1	'	'	'	'	'	'	'	'	'	'
Number of Drilling Rig Contracts Expiring in Year Two	1	'	'	'	'	'	'	'	'	'	'
Number of Drilling Rig Contracts Expiring in Year Three	1	'	'	'	'	'	'	'	'	'	'
Loss Contingency, Estimate of Possible Loss	'	$24,700,000	$6,000,000	'	'	'	'	'	'	'	'
Principal amount of senior notes issued	'	'	'	800,000,000	150,000,000	650,000,000	350,000,000	350,000,000	400,000,000	400,000,000	'
Percentage of Restricted Assets to Net, Assets	'	'	'	'	'	'	'	'	'	'	25.00%
Leases	'	'	'	'	'	'	'	'	'	'	'
Total rental commitments under non-cancelable leases for office space	3,600,000	'	'	'	'	'	'	'	'	'	'
Future minimum lease payments under non-cancelable leases	'	'	'	'	'	'	'	'	'	'	'
2013	295,000	'	'	'	'	'	'	'	'	'	'
2014	1,200,000	'	'	'	'	'	'	'	'	'	'
2015	1,100,000	'	'	'	'	'	'	'	'	'	'
2016	1,000,000	'	'	'	'	'	'	'	'	'	'
2017	$0	'	'	'	'	'	'	'	'	'	'