PDC Energy (PDCE) 10-Q 31 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document Document	9 Months Ended
	Sep. 30, 2013	Oct. 18, 2013
Entity Information [Line Items]	'	'
Entity Registrant Name	'PDC ENERGY, INC.	'
Entity Central Index Key	'0000077877	'
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	'	35,653,050

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$298,488	$2,457
Restricted cash	3,950	3,942
Accounts receivable, net	56,181	64,880
Accounts receivable affiliates	4,784	4,842
Fair value of derivatives	9,660	52,042
Deferred income taxes	22,238	36,151
Prepaid expenses and other current assets	9,073	7,635
Total current assets	404,374	171,949
Properties and equipment, net	1,539,701	1,616,706
Assets held for sale	29,034	0
Fair value of derivatives	5,922	6,883
Other assets	31,932	31,310
Total Assets	2,010,963	1,826,848
Current liabilities:	'	'
Accounts payable	93,520	82,716
Accounts payable affiliates	44	5,296
Production tax liability	23,867	25,899
Fair value of derivatives	14,623	18,439
Funds held for distribution	29,753	34,228
Current portion of long-term debt	104,050	0
Accrued interest payable	19,874	11,056
Other accrued expenses	25,720	25,715
Total current liabilities	311,451	203,349
Long-term debt	549,750	676,579
Deferred income taxes	112,800	148,427
Asset retirement obligation	35,654	61,563
Fair value of derivatives	6,573	10,137
Liabilities held for sale	22,788	0
Other liabilities	20,849	23,612
Total liabilities	1,059,865	1,123,667
Commitments and contingent liabilities	'	'
Shareholders' Equity:	'	'
Preferred shares - par value $0.01 per share, 50,000,000 shares authorized,none issued	0	0
Common shares - par value $0.01 per share, 100,000,000 authorized, 35,657,872 and 30,294,224 issued as of September 30, 2013 and December 31, 2012, respectively	357	303
Additional paid-in capital	670,990	387,494
Retained earnings	280,068	315,568
Treasury shares - at cost, 7,114 and 5,059 as of September 30, 2013 and December 31, 2012, respectively	-317	-184
Total shareholders' equity	951,098	703,181
Total Liabilities and Shareholders' Equity	$2,010,963	$1,826,848

Balance_Sheet_Parenthetical_Pa

Balance Sheet Parenthetical (Parentheticals) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	35,657,872	30,294,224
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Treasury shares, at cost	7,114	5,059

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues:	'	'	'	'
Crude oil, natural gas and NGL sales	$82,136	$52,291	$239,112	$170,588
Sales from natural gas marketing	16,946	11,178	48,695	31,172
Commodity price risk management gain (loss), net	-23,638	-31,943	-21,269	18,287
Well operations, pipeline income and other	1,672	1,194	3,709	3,419
Total revenues	77,116	32,720	270,247	223,466
Costs, expenses and other:	'	'	'	'
Production costs	19,057	15,797	51,091	41,106
Cost of natural gas marketing	17,127	11,260	48,928	30,841
Exploration expense	2,030	1,773	5,156	6,019
Impairment of crude oil and natural gas properties	4,472	388	52,433	1,332
General and administrative expense	16,080	13,710	46,978	42,796
Depreciation, depletion and amortization	30,870	22,121	86,619	73,872
Accretion of asset retirement obligations	1,186	1,101	3,506	2,560
Gain on sale of properties and equipment	-712	-1,508	-759	-3,908
Total cost, expenses and other	90,110	64,642	293,952	194,618
Income (loss) from operations	-12,994	-31,922	-23,705	28,848
Interest expense	-12,509	-11,360	-38,955	-31,857
Interest income	130	3	133	5
Loss from continuing operations before income taxes	-25,373	-43,279	-62,527	-3,004
Provision for income taxes	10,155	15,268	22,856	935
Loss from continuing operations	-15,218	-28,011	-39,671	-2,069
Income (loss) from discontinued operations, net of tax	-782	-4,632	4,171	-2,468
Net loss	($16,000)	($32,643)	($35,500)	($4,537)
Basic	'	'	'	'
Loss from continuing operations	($0.46)	($0.93)	($1.26)	($0.08)
Income (loss) from discontinued operations	($0.02)	($0.15)	$0.13	($0.09)
Net loss	($0.48)	($1.08)	($1.13)	($0.17)
Diluted	'	'	'	'
Loss from continuing operations	($0.46)	($0.93)	($1.26)	($0.08)
Income (loss) from discontinued operations	($0.02)	($0.15)	$0.13	($0.09)
Net loss	($0.48)	($1.08)	($1.13)	($0.17)
Weighted-average common shares outstanding	'	'	'	'
Basic	33,413	30,214	31,350	26,819
Diluted	33,413	30,214	31,350	26,819

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 loss	($35,500)	($4,537)
Adjustments to net loss to reconcile to net cash provided by operating activities:	'	'
Unrealized loss on derivatives, net	-32,057	-20,917
Depreciation, depletion and amortization	88,877	106,745
Impairment of crude oil and natural gas properties	52,436	1,418
Exploratory dry hole costs	0	1,043
Accretion of asset retirement obligation	3,667	2,839
Stock-based compensation	9,991	6,126
(Gain) loss on sale of properties and equipment	-1,571	23,828
Amortization of debt discount and issuance costs	5,093	5,082
Deferred income taxes	-21,714	-7,090
Other	-1,017	4,674
Changes in assets and liabilities	-15,918	13,786
Net cash from operating activities	119,543	127,175
Cash flows from investing activities:	'	'
Capital expenditures	-256,096	-271,769
Acquisition of oil and gas properties	0	-309,285
Proceeds from acquisition adjustments	7,579	11,969
Proceeds from sale of properties and equipment	178,987	192,040
Increase in Restricted Cash	0	17,497
Net cash from investing activities	-69,530	-394,542
Cash flows from financing activities:	'	'
Proceeds from revolving credit facility	252,500	591,250
Payment of revolving credit facility	-278,000	-492,250
Proceeds from sale of common stock, net of issuance costs	275,847	164,496
Other	-4,329	-1,460
Net cash from financing activities	246,018	262,036
Net increase (decrease) in cash and cash equivalents	296,031	-5,331
Cash and cash equivalents, beginning of period	2,457	8,238
Cash and cash equivalents, end of period	298,488	2,907
Cash payments (receipts) for:	'	'
Interest, net of capitalized interest	26,408	30,868
Income taxes	525	1,830
Non-cash investing activities:	'	'
Change in accounts payable related to purchases of properties and equipment	24,308	-9,514
Change in asset retirement obligation, with a corresponding change to natural gas and crude oil properties, net of disposals	$337	$11,871

NATURE_OF_OPERATIONS_AND_BASIS

NATURE OF OPERATIONS AND BASIS OF PRESENTATION	9 Months Ended
	Sep. 30, 2013
NATURE OF OPERATIONS AND BASIS OF PRESENTATION [Abstract]	'
Nature of Operations	'
	NATURE OF OPERATIONS AND BASIS OF PRESENTATION
	PDC Energy, Inc. ("PDC," "PDC Energy," "we," "us" or "the Company") is a domestic independent crude oil, natural gas and NGL company engaged in the exploration for and the acquisition, development, production and marketing of crude oil, natural gas and NGLs. PDC is focused operationally on the liquid-rich Wattenberg Field in the DJ Basin and, in the Appalachian Basin, on the liquid-rich Utica Shale and the dry-gas Marcellus Shale formations. As of September 30, 2013, we owned an interest in approximately 6,250 gross wells. We are engaged in two business segments: (1) Oil and Gas Exploration and Production and (2) Gas Marketing.
	The accompanying unaudited condensed consolidated financial statements include the accounts of PDC, our wholly owned subsidiaries, and our proportionate share of PDC Mountaineer, LLC ("PDCM") and our 21 affiliated partnerships. Pursuant to the proportionate consolidation method, our accompanying condensed consolidated financial statements include our pro rata share of assets, liabilities, revenues and expenses of the entities which we proportionately consolidate. All material intercompany accounts and transactions have been eliminated in consolidation.
	In our opinion, the accompanying condensed consolidated financial statements contain all adjustments (consisting of only normal recurring adjustments) necessary for a fair presentation of our financial statements for interim periods in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the SEC. Accordingly, pursuant to such rules and regulations, certain notes and other financial information included in audited financial statements have been condensed or omitted. The information presented in this Quarterly Report on Form 10-Q should be read in conjunction with our audited consolidated financial statements and notes thereto included in our 2012 Form 10-K. Our results of operations and cash flows for the three and nine months ended September 30, 2013 are not necessarily indicative of the results to be expected for the full year or any other future period.
	Certain reclassifications have been made to prior period financial statements to conform to the current year presentation. These reclassifications had no impact on previously reported cash flows, net income, earnings per share or shareholders' equity.

Recent_Accounting_Standards

Recent Accounting Standards	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Significant Accounting Policies	'
	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Recently Adopted Accounting Standard
	On January 1, 2013, we adopted changes issued by the Financial Accounting Standards Board ("FASB") regarding the disclosure of offsetting assets and liabilities. These changes require an entity to disclose both gross and net information about both instruments and transactions eligible for offset in the statement of financial position and instruments and transactions subject to an enforceable master netting arrangement or similar agreement. The enhanced disclosures enable users of an entity’s financial statements to understand and evaluate the effect or potential effect of master netting arrangements on the entity’s financial position, including the effect or potential effect of rights of setoff associated with certain financial instruments and derivative instruments. Adoption of these changes had no impact on the condensed consolidated financial statements, except for additional disclosures.
	Recently Issued Accounting Standard
	Income Taxes. On July 18, 2013, the FASB issued an update to accounting for income taxes. The update provides clarification on the presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss or a tax credit carryforward exists. The update is effective for public entities for fiscal years, and interim periods within those years, beginning after December 15, 2013. Early adoption is permitted. We are currently evaluating the impact of adopting this update on our financial statements, but do not believe it will have a material impact.

Fair_Value_Measurements_and_Di

Fair Value Measurements and Disclosures	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value, Measurement Inputs, Disclosure	'
	FAIR VALUE OF FINANCIAL INSTRUMENTS
	Derivative Financial Instruments
	Determination of fair value. Our fair value measurements are estimated pursuant to a fair value hierarchy that requires us to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date, giving the highest priority to quoted prices in active markets (Level 1) and the lowest priority to unobservable data (Level 3). In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. In these cases, the lowest level input that is significant to a fair value measurement in its entirety determines the applicable level in the fair value hierarchy. Assessing the significance of a particular input to the fair value measurement in its entirety requires judgment, considering factors specific to the asset or liability, and may affect the valuation of the assets and liabilities and their placement within the fair value hierarchy levels. The three levels of inputs that may be used to measure fair value are defined as:
	Level 1 – Quoted prices (unadjusted) for identical assets or liabilities in active markets.
	Level 2 – Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable for the asset or liability, including quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in inactive markets, inputs other than quoted prices that are observable for the asset or liability and inputs that are derived from observable market data by correlation or other means.
	Level 3 – Unobservable inputs for the asset or liability, including situations where there is little, if any, market activity.
	We measure the fair value of our derivative instruments based on a pricing model that utilizes market-based inputs, including, but not limited to, the contractual price of the underlying position, current market prices, crude oil and natural gas forward curves, discount rates such as the LIBOR curve for a similar duration of each outstanding position, volatility factors and nonperformance risk. Nonperformance risk considers the effect of our credit standing on the fair value of derivative liabilities and the effect of our counterparties' credit standings on the fair value of derivative assets. Both inputs to the model are based on published credit default swap rates and the duration of each outstanding derivative position.
	We validate our fair value measurement through the review of counterparty statements and other supporting documentation, the determination that the source of the inputs is valid, the corroboration of the original source of inputs through access to multiple quotes, if available, or other information and monitoring changes in valuation methods and assumptions. While we use common industry practices to develop our valuation techniques and believe our valuation method is appropriate and consistent with those used by other market participants, changes in our pricing methodologies or the underlying assumptions could result in significantly different fair values.
	Our fixed-price swaps, basis swaps and physical purchases are included in Level 2 and our crude oil and natural gas collars, natural gas calls and physical sales are included in Level 3. The following table presents, for each applicable level within the fair value hierarchy, our derivative assets and liabilities, including both current and non-current portions, measured at fair value on a recurring basis:
		September 30, 2013												December 31, 2012
		Significant Other				Significant				Total				Significant Other				Significant		Total
		Observable				Unobservable								Observable				Unobservable
		Inputs				Inputs								Inputs				Inputs
		(Level 2)				(Level 3)								(Level 2)				(Level 3)
		(in thousands)
	Assets:
	Commodity-based derivative contracts	$	12,328			$	3,060			$	15,388			$	42,788			$	15,734	$	58,522
	Basis protection derivative contracts	182				12				194				387				16		403
	Total assets	12,510				3,072				15,582				43,175				15,750		58,925
	Liabilities:
	Commodity-based derivative contracts	17,293				2,340				19,633				9,839				2,081		11,920
	Basis protection derivative contracts	1,563				—				1,563				16,656				—		16,656
	Total liabilities	18,856				2,340				21,196				26,495				2,081		28,576
	Net asset (liability)	$	(6,346	)		$	732			$	(5,614	)		$	16,680			$	13,669	$	30,349
	The following table presents a reconciliation of our Level 3 assets measured at fair value:
			Three Months Ended September 30,								Nine Months Ended September 30,
			2013				2012				2013				2012
			(in thousands)
	Fair value, net asset, beginning of period		$	3,904			$	28,600			$	13,669			$	22,107
	Changes in fair value included in statement of operations line item:
	Commodity price risk management gain (loss), net		(3,111		)		(9,055		)		(3,008		)		6,098
	Sales from natural gas marketing		11				(4		)		16				35
	Changes in fair value included in balance sheet line item:
	Accounts payable affiliates (1)		—				(93		)		—				(240		)
	Settlements included in statement of operations line items:
	Commodity price risk management gain (loss), net		(66		)		(3,900		)		(5,545		)		(12,357		)
	Sales from natural gas marketing		(6		)		(10		)		(34		)		(105		)
	Income (loss) from discontinued operations, net of tax		—				—				(4,366		)		—
	Fair value, net asset end of period		$	732			$	15,538			$	732			$	15,538
	Changes in unrealized gains (losses) relating to assets (liabilities) still held
	as of period-end, included in statement of operations line item:
	Commodity price risk management gain (loss), net		$	(3,333	)		$	(8,169	)		$	(5,362	)		$	2,577
	Sales from natural gas marketing		(5		)		(13		)		4				(1		)
	Total		$	(3,338	)		$	(8,182	)		$	(5,358	)		$	2,576
	__________
	-1	Represents the change in fair value related to derivative instruments entered into by us and designated to our affiliated partnerships.
	The significant unobservable input used in the fair value measurement of our derivative contracts is the implied volatility curve, which is provided by a third-party vendor. A significant increase or decrease in the implied volatility, in isolation, would have a directionally similar effect resulting in a significantly higher or lower fair value measurement of our Level 3 derivative contracts.
	Non-Derivative Financial Assets and Liabilities
	The carrying values of the financial instruments included in current assets and current liabilities approximate fair value due to the short-term maturities of these instruments.
	The portion of our debt related to our revolving credit facility, as well as our proportionate share of PDCM's credit facility and second lien term loan, approximates fair value due to the variable nature of related interest rates. We have not elected to account for the portion of our debt related to our senior notes under the fair value option; however, as of September 30, 2013, we estimate the fair value of our 3.25% convertible senior notes due 2016 to be $176.4 million, or 153.4% of par value, and our 7.75% senior notes due 2022 to be $528.8 million, or 105.7% of par value. We determined these valuations based upon measurements of trading activity and broker and/or dealer quotes which are published market prices, and therefore are Level 2 inputs.
	Concentration of Risk
	Derivative Counterparties. Our derivative arrangements expose us to credit risk of nonperformance by our counterparties. We primarily use financial institutions who are also lenders under our revolving credit facility as counterparties to our derivative contracts. To date, we have had no counterparty default losses relating to our derivative arrangements. We have evaluated the credit risk of our derivative assets from our counterparties using relevant credit market default rates, giving consideration to amounts outstanding for each counterparty and the duration of each outstanding derivative position. Based on our evaluation, we have determined that the potential impact of nonperformance of our counterparties on the fair value of our derivative instruments was not significant at September 30, 2013, taking into account the estimated likelihood of nonperformance.
	The following table presents the counterparties that expose us to credit risk as of September 30, 2013 with regard to our derivative assets:
	Counterparty Name		Fair Value of
			Derivative Assets
			As of September 30, 2013
			(in thousands)
	JPMorgan Chase Bank, N.A. (1)		$	4,163
	Wells Fargo Bank, N.A. (1)		3,830
	Natixis (1)		1,637
	Bank of Montreal (1)		1,885
	BNP Paribas (1)		1,285
	Other lenders in our revolving credit facility		2,624
Various (2)		158
Total		$	15,582
__________
(1)Major lender in our revolving credit facility. See Note 7, Long-Term Debt.
(2)Represents a total of 20 counterparties.

Derivative_Financial_Instrumen

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2013
Derivative Instruments Not Designated as Hedging Instruments [Abstract]	'
Derivative Instruments and Hedging Activities Disclosure [Text Block]	'
	DERIVATIVE FINANCIAL INSTRUMENTS
	Our results of operations and operating cash flows are affected by changes in market prices for crude oil, natural gas and NGLs. To manage a portion of our exposure to price volatility from producing crude oil and natural gas, we utilize the following economic hedging strategies for each of our business segments.
	•	For crude oil and natural gas sales, we enter into derivative contracts to protect against price declines in future periods. While we structure these derivatives to reduce our exposure to changes in price associated with the derivative commodity, they also limit the benefit we might otherwise have received from price increases in the physical market.
	•	For natural gas marketing, we enter into fixed-price physical purchase and sale agreements that qualify as derivative contracts. In order to offset the fixed-price physical derivatives in our natural gas marketing, we enter into financial derivative instruments that have the effect of locking in the prices we will receive or pay for the same volumes and period, offsetting the physical derivative.
	We believe our derivative instruments continue to be effective in achieving the risk management objectives for which they were intended. As of September 30, 2013, we had derivative instruments, which were comprised of commodity floors, collars and swaps, basis protection swaps and physical sales and purchases, in place for a portion of our anticipated production through 2017 for a total of 51,305 BBtu of natural gas and 7,735 MBbls of crude oil. The majority of our derivative contracts are entered into at no cost to us as we hedge our anticipated production at the then-prevailing commodity market prices.
	We have elected not to designate any of our derivative instruments as hedges and therefore do not qualify for use of hedge accounting. Accordingly, changes in the fair value of our derivative instruments are recorded in the statements of operations, with the exception of changes in fair value related to those derivatives we designated to our affiliated partnerships. Changes in the fair value of derivative instruments related to our Oil and Gas Exploration and Production segment are recorded in commodity price risk management, net. Changes in the fair value of derivative instruments related to our Gas Marketing segment are recorded in sales from and cost of natural gas marketing. Changes in the fair value of the derivative instruments designated to our affiliated partnerships are recorded on the condensed consolidated balance sheets in accounts payable affiliates and accounts receivable affiliates. As positions designated to our affiliated partnerships settle, the realized gains and losses are netted for distribution. Net realized gains are paid to the partnerships and net realized losses are deducted from the partnerships’ cash distributions from production. The affiliated partnerships bear their designated share of counterparty risk. As of September 30, 2013, our affiliated partnerships had no outstanding derivative instruments.
	The following table presents the location and fair value amounts of our derivative instruments on the condensed consolidated balance sheets as of September 30, 2013 and December 31, 2012:
						Fair Value
	Derivatives instruments:			Balance sheet line item		September 30, 2013				31-Dec-12
						(in thousands)
	Derivative assets:	Current
		Commodity contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		$	9,067			$	47,016
		Related to affiliated partnerships (1)		Fair value of derivatives		—				4,707
		Related to natural gas marketing		Fair value of derivatives		444				302
		Basis protection contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		133				—
		Related to natural gas marketing		Fair value of derivatives		16				17
						9,660				52,042
		Non Current
		Commodity contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		5,792				6,671
		Related to natural gas marketing		Fair value of derivatives		85				203
		Basis protection contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		44				—
		Related to natural gas marketing		Fair value of derivatives		1				9
						5,922				6,883
	Total derivative assets					$	15,582			$	58,925
	Derivative liabilities:	Current
		Commodity contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		$	12,880			$	1,744
		Related to natural gas marketing		Fair value of derivatives		310				226
		Basis protection contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		1,433				14,329
		Related to affiliated partnerships (2)		Fair value of derivatives		—				2,140
						14,623				18,439
		Non Current
		Commodity contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		6,403				9,969
		Related to natural gas marketing		Fair value of derivatives		40				168
		Basis protection contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		130				—
						6,573				10,137
	Total derivative liabilities					$	21,196			$	28,576
	__________
	-1	Represents derivative positions designated to our affiliated partnerships. Accordingly, our accompanying December 31, 2012 condensed consolidated balance sheet includes a corresponding payable to our affiliated partnerships representing their proportionate share of the derivative assets.
	-2	Represents derivative positions designated to our affiliated partnerships. Accordingly, our accompanying December 31, 2012 condensed consolidated balance sheet includes a corresponding receivable from our affiliated partnerships representing their proportionate share of the derivative liabilities.
	The following table presents the impact of our derivative instruments on our statements of operations:
			2013											2012
	Statement of operations line item		Reclassification				Realized and Unrealized				Total			Reclassification			Realized and Unrealized			Total
			of Realized				Gains							of Realized			Gains
			Gains (Losses)				(Losses) For							Gains (Losses)			(Losses) For
			Included in Prior Periods				the							Included in Prior Periods			the
			Unrealized				Current							Unrealized			Current
							Period										Period
			(in thousands)
	Three Months Ended September 30,
	Commodity price risk management gain (loss), net
	Realized gains (losses)		$	2,936			$	(4,461	)		$	(1,525	)	$	15,010		$	(1,915	)	$	13,095
	Unrealized losses		(2,936		)		(19,177		)		(22,113		)	(15,010		)	(30,028		)	(45,038		)
	Total commodity price risk management gain (loss), net		$	—			$	(23,638	)		$	(23,638	)	$	—		$	(31,943	)	$	(31,943	)
	Sales from natural gas marketing
	Realized gains (losses)		$	249			$	(9	)		$	240		$	386		$	15		$	401
Unrealized losses		(249		)		(62		)		(311		)	(386		)	(404		)	(790		)
Total sales from natural gas marketing		$	—			$	(71	)		$	(71	)	$	—		$	(389	)	$	(389	)
Cost of natural gas marketing
Realized gains (losses)		$	(196	)		$	8			$	(188	)	$	(364	)	$	(20	)	$	(384	)
Unrealized gains		196				82				278			364			467			831
Total cost of natural gas marketing		$	—			$	90			$	90		$	—		$	447		$	447
Nine Months Ended September 30,
Commodity price risk management gain (loss), net
Realized gains (losses)		$	25,273			$	(14,426	)		$	10,847		$	22,813		$	16,387		$	39,200
Unrealized gains (losses)		(25,273		)		(6,843		)		(32,116		)	(22,813		)	1,900			(20,913		)
Total commodity price risk management gain (loss), net		$	—			$	(21,269	)		$	(21,269	)	$	—		$	18,287		$	18,287
Sales from natural gas marketing
Realized gains		$	206			$	61			$	267		$	1,358		$	588		$	1,946
Unrealized gains (losses)		(206		)		546				340			(1,358		)	(428		)	(1,786		)
Total sales from natural gas marketing		$	—			$	607			$	607		$	—		$	160		$	160
Cost of natural gas marketing
Realized gains (losses)		$	(133	)		$	8			$	(125	)	$	(1,195	)	$	(652	)	$	(1,847	)
Unrealized gains (losses)		133				(414		)		(281		)	1,195			587			1,782
Total cost of natural gas marketing		$	—			$	(406	)		$	(406	)	$	—		$	(65	)	$	(65	)
All of our financial derivative agreements contain master netting provisions that provide for the net settlement of all contracts through a single payment in the event of early termination. Our fixed-price physical purchase and sale agreements that qualify as derivative contracts are not subject to master netting provisions and are not significant. We have elected not to offset the fair value positions recorded on our condensed consolidated balance sheets.
The following table reflects the impact of netting agreements on gross derivative assets and liabilities as of September 30, 2013 and December 31, 2012:
As of September 30, 2013		Derivatives instruments, recorded in condensed consolidated balance sheet, gross				Effect of master netting agreements				Derivative instruments, net
		(in thousands)
Asset derivatives:
Derivative instruments, at fair value		$	15,582			$	(11,739	)		$	3,843
Liability derivatives:
Derivative instruments, at fair value		$	21,196			$	(11,739	)		$	9,457
As of December 31, 2012		Derivatives instruments, recorded in condensed consolidated balance sheet, gross				Effect of master netting agreements				Derivative instruments, net
		(in thousands)
Asset derivatives:
Derivative instruments, at fair value		$	58,925			$	(11,437	)		$	47,488
Liability derivatives:
Derivative instruments, at fair value		$	28,576			$	(11,437	)		$	17,139

Properties_and_Equipment

Properties and Equipment	9 Months Ended
	Sep. 30, 2013
Oil and Gas Property [Abstract]	'
Property, Plant and Equipment Disclosure	'
	PROPERTIES AND EQUIPMENT
	The following table presents the components of properties and equipment, net of accumulated depreciation, depletion and amortization:
		September 30, 2013			31-Dec-12
		(in thousands)
	Properties and equipment, net:
	Crude oil and natural gas properties
	Proved	$	1,533,430		$	2,075,924
	Unproved	315,233			319,327
	Total crude oil and natural gas properties	1,848,663			2,395,251
	Pipelines and related facilities	15,749			47,786
	Equipment and other	28,780			34,858
	Land and buildings	13,612			14,935
	Construction in progress	146,921			67,217
	Gross properties and equipment	2,053,725			2,560,047
	Accumulated depreciation, depletion and amortization	(514,024		)	(943,341		)
	Properties and equipment, net	$	1,539,701		$	1,616,706
	The above decrease in property and equipment, net, includes decreases in crude oil and natural gas properties, pipelines and related facilities and equipment and other in the amount of $780.0 million and accumulated depreciation, depletion and amortization in the amount of $566.4 million attributable to the divestiture of our Piceance Basin, NECO and certain other non-core Colorado properties in June 2013 and the classification of our shallow upper Devonian (non-Marcellus Shale) Appalachian Basin crude oil and natural gas properties as held for sale in the condensed consolidated balance sheet as of September 30, 2013. See Note 12, Assets Held for Sale, Divestitures and Discontinued Operations, for additional information regarding these properties.
	The following table presents impairment charges recorded for crude oil and natural gas properties:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013		2012
		(in thousands)
	Continuing operations:
	Impairment of proved properties	$	3,750		$	—		$	48,750	$	—
	Impairment of individually significant unproved properties	154			154			979		462
	Amortization of individually insignificant unproved properties	568			234			2,704		870
	Total continuing operations	4,472			388			52,433		1,332
	Discontinued operations:
	Amortization of individually insignificant unproved properties	—			7			3		86
	Total discontinued operations	—			7			3		86
	Total impairment of crude oil and natural gas properties	$	4,472		$	395		$	52,436	$	1,418
	In the first quarter of 2013, we recognized an impairment charge of approximately $45.0 million related to all of our shallow upper Devonian (non-Marcellus Shale) Appalachian Basin producing properties located in West Virginia and Pennsylvania owned directly by us, as well as through our proportionate share of PDCM and our affiliated partnerships. The impairment charge represented the excess of the carrying value of the assets over the estimated fair value, less cost to sell. The fair value of the assets was determined based upon estimated future cash flows from unrelated third-party bids, a Level 3 input. Pursuant to a purchase and sale agreement dated October 8, 2013 with an unrelated third-party, we determined that the carrying value of the above-mentioned properties exceeded the transaction sales price, a Level 3 input, less costs to sell. As a result, we recognized an additional impairment charge of approximately $3.8 million in the third quarter of 2013 to reduce the carrying value of the net assets to reflect the current net sales price. The impairment charge was included in the statement of operations line item impairment of crude oil and natural gas properties. See Note 12, Assets Held for Sale, Divestitures and Discontinued Operations, and Note 15, Subsequent Events, for additional information regarding the potential sale of these properties. We expect this sale to close in the fourth quarter of 2013. However, there can be no assurance we will be successful in closing this divestiture.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Income Tax Disclosure	'
	INCOME TAXES
	We evaluate our estimated annual effective income tax rate on a quarterly basis based on current and forecasted operating results and tax laws. The estimated annual effective tax rate is adjusted quarterly based upon actual results and updated operating forecasts. Consequently, based upon the mix and timing of our actual earnings compared to annual projections, our effective tax rate may vary quarterly and may make quarterly comparisons not meaningful. A tax expense or benefit unrelated to the current year income or loss is recognized in its entirety as a discrete item of tax in the period identified. The quarterly income tax provision is generally comprised of tax expense on income or tax benefit on loss at the most recent estimated annual effective tax rate, adjusted for the effect of discrete items.
	The effective tax rate for continuing operations for the three and nine months ended September 30, 2013 was a 40.0% and 36.6%, respectively, benefit on loss compared to a 35.3% and 31.1% benefit on loss for the three and nine months ended September 30, 2012, respectively. The effective tax rates for the three and nine months ended September 30, 2013 differ from the statutory rate primarily due to net permanent additions, largely nondeductible officers' compensation, partially offset by percentage depletion deductions. The effective tax rates for the three and nine months ended September 30, 2012 differ from the statutory rate primarily due to net permanent deductions, largely percentage depletion, partially offset by nondeductible officer's compensation. There were no significant discrete items recorded during the three and nine months ended September 30, 2013 or 2012.
	As of September 30, 2013, we had a gross liability for unrecognized tax benefits of $0.2 million, unchanged from the amount recorded at December 31, 2012. If recognized, this liability would affect our effective tax rate. This liability is reflected in other accrued expenses on our accompanying condensed consolidated balance sheets. We expect our remaining liability for uncertain tax positions to decrease in the next twelve months due to the expiration of the statute of limitations.
	As of the date of this report, we are current with our income tax filings in all applicable state jurisdictions. We have received notice from the State of Colorado that our 2008 through current state income tax returns have been selected for audit.

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Long-term Debt	'
	LONG-TERM DEBT
	Long-term debt consists of the following:
		September 30, 2013			31-Dec-12
		(in thousands)
	Senior notes:
	3.25% Convertible senior notes due 2016:
	Principal amount	$	115,000		$	115,000
	Unamortized discount	(10,950		)	(13,671		)
	3.25% Convertible senior notes due 2016, net of discount	104,050			101,329
	7.75% Senior notes due 2022	500,000			500,000
	Total senior notes	604,050			601,329
	Credit facilities:
	Corporate	—			49,000
	PDCM	34,750			26,250
	Total credit facilities	34,750			75,250
	PDCM second lien term loan	15,000			—
	Total debt	653,800			676,579
	Less: Current portion of long-term debt	104,050			—
	Long-term debt	$	549,750		$	676,579
	Senior Notes
	3.25% Convertible Senior Notes Due 2016. In November 2010, we issued $115 million aggregate principal amount 3.25% convertible senior notes due May 15, 2016 (the "Convertible Notes") in a private placement to qualified institutional investors. Interest on the Convertible Notes is payable semi-annually in arrears on each May 15 and November 15. We allocated the gross proceeds of the Convertible Notes between the liability and equity components of the debt. The initial $94.3 million liability component was determined based upon the fair value of similar debt instruments with similar terms, excluding the conversion feature, and priced on the same day we issued the Convertible Notes. The original issue discount and capitalized debt issuance costs are being amortized to interest expense over the life of the notes using an effective interest rate of 7.4%.
	Upon conversion, the Convertible Notes may be settled, at our election, in shares of our common stock, cash or a combination of cash and shares of our common stock. We have initially elected a net-settlement method to satisfy our conversion obligation, which allows us to settle the principal amount of the Convertible Notes in cash and to settle the excess conversion value in shares, as well as cash in lieu of fractional shares.
	The Convertible Notes became convertible at the option of holders beginning October 1, 2013. The conversion right was triggered on September 20, 2013, when the closing sale price of our common stock on the NASDAQ Global Select Market exceeded $55.12 (130% of the applicable conversion price) for the 20th trading day in the 30 consecutive trading days ending on September 30, 2013. In the event a holder elects to convert its note, we expect to fund any cash settlement of any such conversion from working capital and/or borrowings under our revolving credit facility. As a result of the Convertible Notes becoming convertible, we have included the carrying value of the Convertible Notes, net of discount, in the current portion of long-term debt on our condensed consolidated balance sheet as of September 30, 2013. We will reassess the convertibility of the Convertible Notes, and the related balance sheet classification, on a quarterly basis. In the event that a holder exercises the right to convert its note, we will write-off a ratable portion of the remaining debt issuance costs and unamortized discount to interest expense. Based on a September 30, 2013 stock price of $59.54, the “if-converted” value of the Convertible Notes exceeded the principal amount by approximately $46.5 million.
	7.75% Senior Notes Due 2022. In October 2012, we issued $500 million aggregate principal amount 7.75% senior notes due October 15, 2022 (the “2022 Senior Notes”) in a private placement to qualified institutional investors. Interest on the 2022 Senior Notes is payable semi-annually in arrears on each April 15 and October 15. The indenture governing the notes contains customary restrictive incurrence covenants. Capitalized debt issuance costs are being amortized as interest expense over the life of the notes using the effective interest method.
	As of September 30, 2013, we were in compliance with all covenants related to the Convertible Notes and the 2022 Senior Notes, and expect to remain in compliance throughout the next twelve-month period.
	In connection with the issuance of the 2022 Senior Notes, we entered into a registration rights agreement with the initial purchasers in which we agreed to file a registration statement with the SEC related to an offer to exchange the notes for substantially identical registered notes and to use commercially reasonable efforts to cause the exchange offer to be completed on or prior to September 28, 2013. The registration statement was declared effective by the SEC in July 2013 and the exchange offer was completed in August 2013.
	Credit Facilities
	Revolving Credit Facility. In May 2013, we entered into a Third Amended and Restated Credit Agreement with JPMorgan Chase Bank, N.A. as administrative agent and other lenders party thereto. This agreement amends and restates the credit agreement dated November 2010 and expires in May 2018. The revolving credit facility is available for working capital requirements, capital expenditures, acquisitions, general corporate purposes and to support letters of credit. The revolving credit facility provides for a maximum of $1 billion in allowable borrowing capacity, subject to the borrowing base. As of September 30, 2013, the borrowing base was $450 million. The borrowing base is based on, among other things, the loan value assigned to the proved reserves attributable to our and our subsidiaries' crude oil and natural gas interests, excluding proved reserves attributable to PDCM and our 21 affiliated partnerships. The borrowing base is subject to a semi-annual size redetermination based upon quantification of our reserves at June 30 and December 31, and is also subject to a redetermination upon the occurrence of certain events. The revolving credit facility is secured by a pledge of the stock of certain of our subsidiaries, mortgages of certain producing crude oil and natural gas properties and substantially all of our and such subsidiaries' other assets. Neither PDCM nor our affiliated partnerships are guarantors of the revolving credit facility. As of September 30, 2013, we had no outstanding draws on our revolving credit facility compared to $49.0 million at a weighted-average interest rate of 2.3% as of December 31, 2012.
	The revolving credit facility contains covenants customary for agreements of this type, with the most restrictive being certain financial tests and requirements to maintain certain financial ratios on a quarterly basis. The financial tests and ratios, as defined per the revolving credit facility, include requirements to maintain a minimum current ratio of 1.00 to 1.00 and to not exceed a maximum leverage ratio of 4.25 to 1.00. As of September 30, 2013, we were in compliance with all the revolving credit facility covenants and expect to remain in compliance throughout the next twelve-month period.
	As of September 30, 2013, Riley Natural Gas, a wholly owned subsidiary of PDC, had an approximately $11.8 million irrevocable standby letter of credit in favor of a third-party transportation service provider to secure firm transportation of the natural gas produced by third-party producers for whom we market production in the Appalachian Basin. In addition, PDC had an approximately $6.7 million irrevocable standby letter of credit to secure firm transportation of natural gas that we produce. The letters of credit reduce the amount of available funds under our revolving credit facility by an equal amount. The letters of credit expire on September 17, 2014. As of September 30, 2013, the available funds under our revolving credit facility, including a reduction for the $18.5 million irrevocable standby letters of credit in effect, was $431.5 million.
	In October 2013, pursuant to an agreement our $6.7 million irrevocable standby letter of credit will be novated to the buyer of PDCM's shallow upper Devonian properties upon the closing of the transaction. See Note 15, Subsequent Events, for additional information regarding the potential sale. We expect this sale to close in the fourth quarter of 2013. However, there can be no assurance we will be successful in closing this divestiture.
	PDCM Credit Facility. PDCM has a credit facility dated April 2010, as amended in May 2013, with a borrowing base of $80 million, of which our proportionate share is $40 million. The maximum allowable facility amount is $400 million. No principal payments are required until the credit agreement expires in April 2017, or in the event that the borrowing base falls below the outstanding balance. The credit facility is subject to and secured by PDCM's properties, including our proportionate share of such properties. The borrowing base is subject to size redetermination semi-annually based upon a valuation of PDCM's reserves at June 30 and December 31. Either PDCM or the lenders may request a redetermination upon the occurrence of certain events. The credit facility will be utilized by PDCM for the exploration and development of its Marcellus Shale assets.
	The credit facility contains covenants customary for agreements of this type, with the most restrictive being certain financial tests and financial ratios that must be met on a quarterly basis. The financial tests and ratios, as defined by the credit facility, include requirements to maintain a minimum current ratio of 1.0 to 1.0, not to exceed a debt to EBITDAX ratio of 4.25 to 1.0 (declining to 4.0 to 1.0 on July 1, 2014) and to maintain a minimum interest coverage ratio of 2.5 to 1.0. As of September 30, 2013, our proportionate share of PDCM's outstanding credit facility balance was $34.8 million compared to $26.3 million as of December 31, 2012. The weighted-average borrowing rate on PDCM's credit facility was 3.6% per annum as of September 30, 2013, compared to 3.5% as of December 31, 2012.
	As of September 30, 2013, PDCM was not in compliance with the minimum current ratio and debt to EBITDAX ratio covenants under the PDCM credit facility. In October 2013, PDCM received a waiver from Wells Fargo regarding the covenant violation. PDCM expects to maintain compliance with all PDCM credit facility covenants throughout the next twelve-month period.
	PDCM Second Lien Term Loan
	In July 2013, PDCM entered into a Second Lien Credit Agreement ("Term Loan Agreement") with Wells Fargo Energy Capital as administrative agent and a syndicate of other lenders party thereto. The aggregate commitment under the Term Loan Agreement is $30 million, of which our proportionate share is $15 million. The aggregate commitment may increase periodically up to a maximum of $75 million, as PDCM's assets grow and the covenants under the Term Loan Agreement allow. The Term Loan matures on October 31, 2017. Amounts borrowed accrue interest, at PDCM's discretion, at either an alternative base rate plus a margin of 6% per annum or an adjusted LIBOR for the interest period in effect plus a margin of 7% per annum. As of September 30, 2013, amounts borrowed and outstanding on the Term Loan were $30.0 million, of which our proportionate share is $15.0 million. The weighted-average borrowing rate on the Term Loan was 8.5% per annum as of September 30, 2013.
	The Term Loan Agreement contains financial covenants that must be met on a quarterly basis, including requirements to maintain a minimum current ratio of 1.0 to 1.0, not to exceed a debt to EBITDAX ratio of 4.5 to 1.0, to maintain a minimum interest coverage ratio of 2.25 to 1.0 and not to exceed a present value of future net revenues to total debt ratio of 1.50 to 1.00. As of September 30, 2013, PDCM was not in compliance with the minimum current ratio and the debt to EBITDAX ratio covenants under the Term Loan Agreement. In October 2013, PDCM received a waiver from Wells Fargo regarding the covenant violation. PDCM expects to maintain compliance with all Term Loan Agreement covenants throughout the next twelve-month period.

Asset_Retirement_Obligations

Asset Retirement Obligations	9 Months Ended
	Sep. 30, 2013
Asset Retirement Obligation Disclosure [Abstract]	'
Asset Retirement Obligation Disclosure	'
	ASSET RETIREMENT OBLIGATIONS
	The following table presents the changes in carrying amounts of the asset retirement obligations associated with our working interest in crude oil and natural gas properties:
		Amount
		(in thousands)
	Balance at December 31, 2012	$	62,563
	Obligations incurred with development activities	337
	Accretion expense	3,667
	Revisions in estimated cash flows	251
	Obligations discharged with divestitures of properties and asset retirements	(7,376		)
	Balance at September 30, 2013	59,442
	Less: Liabilities held for sale (1)	22,788
	Less: Current portion	1,000
	Long-term portion	$	35,654
	______________
	-1	Represents asset retirement obligations related to our assets held for sale. See Note 12, Assets Held for Sale, Divestitures and Discontinued Operations and Note 15, Subsequent Events, for additional information regarding the potential sale of these properties.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies Disclosure	'
	COMMITMENTS AND CONTINGENCIES
	Firm Transportation Agreements. We enter into contracts that provide firm transportation, sales and processing services on pipeline systems through which we transport or sell natural gas. Volumes produced by us, PDCM, our affiliated partnerships and other third-party working interest owners can be used to satisfy volume requirements, as can volumes purchased from third parties. We record in our financial statements only our share of costs based upon our working interest in the wells. These contracts require us to pay these transportation and processing charges whether the required volumes are delivered or not. With the exception of contracts entered into by PDCM, the costs of any volume shortfalls are borne by PDC.
	The following table presents gross volume information, including our proportionate share of PDCM, related to our long-term firm transportation, sales and processing agreements for pipeline capacity:
		For the Twelve Months Ending September 30,
	Area	2014		2015		2016		2017		2018 and		Total		Expiration
										Through				Date
										Expiration
	Volume (MMcf)
	West Virginia	21,428		22,868		24,874		24,862		149,603		243,635		January 31, 2026
	Utica Shale	2,282		2,738		2,738		2,738		15,966		26,462		July 22, 2023
	Total	23,710		25,606		27,612		27,600		165,569		270,097
	Dollar commitment	$	9,601	$	10,056	$	10,462	$	10,294	$	47,785	$	88,198
	(in thousands)
	In March 2013, we entered into long-term agreements with a subsidiary of MarkWest Energy Partners, LP to provide midstream services, including gas gathering, processing, fractionation and marketing, to support our Utica Shale operations in Guernsey County in Southeast Ohio. The primary term of the agreements commenced in July 2013 when our natural gas began to flow into the gathering system. The gas processing agreement includes minimum volume commitments as shown in the table above, with certain fees assessed for any shortfall.
	In June 2013, we closed a transaction pursuant to which our Piceance Basin and NECO firm gathering commitments were assumed by the buyer of certain of our oil and natural gas properties. See Note 12, Assets Held for Sale, Divestitures, and Discontinued Operations, for additional information regarding the sale of our non-core Colorado assets.
	In October 2013, pursuant to a purchase and sale agreement an existing agreement for firm transportation services of approximately 34,572 MMcf, representing a dollar commitment of $16.5 million, in the Appalachian Basin will be novated to the buyer of PDCM's shallow upper Devonian crude oil and natural gas properties, thereby relieving the Company of all obligations or liabilities arising under the agreement. See Note 15, Subsequent Events, for additional information regarding the potential sale. We expect this sale to close in the fourth quarter of 2013. However, there can be no assurance we will be successful in closing this divestiture.
	Litigation. The Company is involved in various legal proceedings that it considers normal to its business. The Company reviews the status of these proceedings on an ongoing basis and, from time to time, may settle or otherwise resolve these matters on terms and conditions that management believes are in the best interests of the Company. There is no assurance that settlements can be reached on acceptable terms or that adverse judgments, if any, in the remaining litigation will not exceed the amounts reserved. Although the results cannot be known with certainty, we currently believe that the ultimate results of such proceedings will not have a material adverse effect on our financial position, results of operations or liquidity.
	Alleged Class Action Filed Regarding 2010 and 2011 Partnership Purchases
	On December 21, 2011 the Company and its wholly-owned merger subsidiary were served with an alleged class action on behalf of certain former partnership unit holders, related to its partnership repurchases completed by mergers in 2010 and 2011. The action was filed in U.S. District Court for the Central District of California and is titled Schulein v. Petroleum Development Corp. The complaint primarily alleges that the disclosures in the proxy statements issued in connection with the mergers were inadequate, and a state law breach of fiduciary duty. On June 15, 2012, the Court denied the Company's motion to dismiss and approved a litigation schedule including a jury trial in May 2014. We have not recorded a liability for claims pending because we believe we have good legal defenses to the asserted claims and because the plaintiffs have not specified damages and it is not possible for management to reasonably estimate what, if any, monetary damages could result from this claim.
	Environmental. Due to the nature of the natural gas and oil industry, we are exposed to environmental risks. We have various policies and procedures to avoid environmental contamination and mitigate the risks from environmental contamination. We conduct periodic reviews to identify changes in our environmental risk profile. Liabilities are recorded when environmental damages resulting from past events are probable and the costs can be reasonably estimated. As of September 30, 2013 and December 31, 2012, we had accrued environmental liabilities in the amount of $5.6 million and $8.4 million, respectively, included in other accrued expenses on the condensed consolidated balance sheets. We are not aware of any environmental claims existing as of September 30, 2013 which have not been provided for or would otherwise have a material impact on our financial statements. However, there can be no assurance that current regulatory requirements will not change or unknown past non-compliance with environmental laws will not be discovered on our properties.
	Partnership Repurchase Provision. Substantially all of our drilling programs contain a repurchase provision pursuant to which investing partners may request that we purchase their partnership units at any time beginning with the third anniversary of the first cash distribution. The provision provides that we are obligated to purchase an aggregate of 10% of the initial subscriptions per calendar year (at a minimum price of four times the most recent 12 months' cash distributions from production), if repurchase is requested by investors, subject to our financial ability to do so. As of September 30, 2013, the maximum annual repurchase obligation, based upon the minimum price described above, was approximately $4.2 million. We believe we have adequate liquidity to meet this potential obligation. For the quarter ended September 30, 2013, amounts paid for the repurchase of partnership units pursuant to this provision were immaterial.
	Employment Agreements with Executive Officers. Each of our senior executive officers may be entitled to a severance payment and certain other benefits upon the termination of the officer's employment pursuant to the officer's employment agreement and/or the Company's executive severance compensation plan. The nature and amount of such benefits would vary based upon, among other things, whether the termination followed a change of control of the Company.

Common_Stock

Common Stock	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award	'
	COMMON STOCK
	Sale of Equity Securities
	In August 2013, we completed a public offering of 5,175,000 shares of our common stock, par value $0.01 per share, at a price to us of $53.37 per share, resulting in total shares outstanding of 35,650,758 as of September 30, 2013. Net proceeds of the offering were approximately $275.8 million, after deducting offering expenses and underwriting discounts, of which $51,750 is included in common shares-par value and approximately $275.8 million is included in additional paid-in capital on the condensed consolidated balance sheet. The shares were issued pursuant to an effective shelf registration statement on Form S-3 filed with the SEC in January 2012.
	Stock-Based Compensation Plans
	The following table provides a summary of the impact of our outstanding stock-based compensation plans on the results of operations for the periods presented:
			Three Months Ended September 30,							Nine Months Ended September 30,
			2013				2012			2013			2012
			(in thousands)
	Stock-based compensation expense		$	3,040			$	2,225		$	9,991		$	6,126
	Income tax benefit		(1,161		)		(847		)	(3,816		)	(2,333		)
	Net stock-based compensation expense		$	1,879			$	1,378		$	6,175		$	3,793
	Stock Appreciation Rights ("SARs")
	The SARs vest ratably over a three-year period and may be exercised at any point after vesting through 10 years from the date of issuance. Pursuant to the terms of the awards, upon exercise, the executive officers will receive, in shares of common stock, the excess of the market price of the award on the date of exercise over the market price of the award on the date of issuance.
	In January 2013, the Compensation Committee awarded 87,078 SARs to our executive officers. The fair value of each SAR award was estimated on the date of grant using a Black-Scholes pricing model using the following assumptions:
		Grant-Year
		2013				2012
	Expected term of award	6 years				6 years
	Risk-free interest rate	1		%		1.1		%
	Expected volatility	65.5		%		64.3		%
	Weighted-average grant date fair value per share	$	21.96			$	17.61
	The expected life of the award was estimated using historical stock option exercise behavior data. The risk-free interest rate was based on the U.S. Treasury yields approximating the expected life of the award in effect at the time of grant. Expected volatilities were based on our historical volatility. We do not expect to pay or declare dividends in the foreseeable future.
	The following table presents the changes in our SARs:
		Nine Months Ended September 30,
		2013												2012
		Number of			Weighted-Average				Average Remaining Contractual		Aggregate Intrinsic			Number of		Weighted-Average		Average Remaining Contractual	Aggregate Intrinsic
		SARs			Exercise				Term (in years)		Value (in thousands)			SARs		Exercise		Term (in years)	Value (in thousands)
					Price											Price
	Outstanding beginning of year, January 1,	118,832			$	30.8			8.4		$	486		50,471		$	31.61	8.6	$	341
	Awarded	87,078			37.18				—		—			68,361		30.19		9.3	—
	Outstanding at September 30,	205,910			33.5				8.4		5,363			118,832		30.8		8.7	328
	Vested and expected to vest at September 30,	198,163			33.41				8.4		5,178			113,426		30.77		8.7	319
	Exercisable at September 30,	67,069			29.99				7.3		1,982			27,458		28.84		7.8	153
	Total compensation cost related to SARs granted, net of estimated forfeitures, and not yet recognized in our statement of operations as of September 30, 2013 was $2.0 million. The cost is expected to be recognized over a weighted-average period of 2.0 years.
	Restricted Stock Awards
	Time-Based Awards. The fair value of the time-based restricted shares is amortized ratably over the requisite service period, primarily three or four years. The time-based shares vest ratably on each annual anniversary following the grant date if the participant is continuously employed.
	In January 2013, the Compensation Committee awarded a total of 103,050 time-based restricted shares to our executive officers that vest ratably over a three-year period ending on January 16, 2016.
	The following table presents the changes in non-vested time-based awards for the nine months ended September 30, 2013:
		Shares			Weighted-Average
					Grant-Date
					Fair Value
	Non-vested at December 31, 2012	646,490			$	27.93
	Granted	292,548			44.56
	Vested	(265,312	)		27.53
	Forfeited	(22,507	)		31.29
	Non-vested at September 30, 2013	651,219			35.45
		As of/Year Ended September 30,
		2013				2012
		(in thousands, except per share data)
	Total intrinsic value of time-based awards vested	$	12,562			$	4,818
	Total intrinsic value of time-based awards non-vested	38,774				21,996
	Market price per common share as of September 30,	59.54				31.63
	Weighted-average grant date fair value per share	44.56				26.48
	Total compensation cost related to non-vested time-based awards, net of estimated forfeitures, and not yet recognized in our statements of operations as of September 30, 2013 was $16.8 million. This cost is expected to be recognized over a weighted-average period of 2.1 years.
	Market-Based Awards. The fair value of the market-based restricted shares is amortized ratably over the requisite service period, primarily three years. The market-based shares vest if the participant is continuously employed throughout the performance period and the market-based performance measure is achieved, with a maximum vesting period of three to five years. All compensation cost related to the market-based awards will be recognized if the requisite service period is fulfilled, even if the market condition is not achieved.
	In January 2013, the Compensation Committee awarded a total of 41,570 market-based restricted shares to our executive officers. In addition to continuous employment, the vesting of these shares is contingent on the Company's total shareholder return ("TSR"), which is essentially the Company’s stock price change including any dividends, as compared to the TSR of a set group of 16 peer companies. The shares are measured over a three-year period ending on December 31, 2015 and can result in a payout between 0% and 200% of the total shares awarded. The weighted-average grant date fair value per market-based share for these awards granted was computed using the Monte Carlo pricing model using the following assumptions:
			Nine Months Ended September 30,
			2013				2012
	Expected term of award		3 years				3 years
	Risk-free interest rate		0.4		%		0.3		%
	Expected volatility		56.6		%		65.3		%
	Weighted-average grant date fair value per share		$	49.04			$	36.54
	The expected term of the awards was based on the requisite service period. The risk-free interest rate was based on the U.S. Treasury yields in effect at the time of grant and extrapolated to approximate the life of the award. The expected volatility was based on our historical volatility. We do not expect to pay or declare dividends in the foreseeable future.
	The following table presents the change in non-vested market-based awards during nine months ended September 30, 2013:
		Shares			Weighted-Average
					Grant-Date
					Fair Value per Share
Non-vested at December 31, 2012		40,696			$	39.22
Granted		41,570			49.04
Non-vested at September 30, 2013		82,266			44.18
	As of/Year Ended September 30,
	2013				2012
	(in thousands, except per share data)
Total intrinsic value of market-based awards non-vested	$	4,898			$	2,329
Market price per common share as of September 30,	59.54				31.63
Weighted-average grant date fair value per share	49.04				36.54
Total compensation cost related to non-vested market-based awards, net of estimated forfeitures, and not yet recognized in our statement of operations as of September 30, 2013 was $2.0 million. This cost is expected to be recognized over a weighted-average period of 2.0 years.

Earnings_per_share

Earnings per share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	EARNINGS PER SHARE
	Basic earnings per share is computed by dividing net earnings by the weighted-average number of common shares outstanding for the period. Diluted earnings per share is similarly computed except that the denominator includes the effect, using the treasury stock method, of unvested restricted stock, outstanding SARs, stock options, Convertible Notes and shares held pursuant to our non-employee director deferred compensation plan, if including such potential shares of common stock is dilutive.
	The following table presents a reconciliation of the weighted-average diluted shares outstanding:
		Three Months Ended September 30,		Nine Months Ended September 30,
		2013	2012	2013	2012
		(in thousands)
	Weighted-average common shares outstanding - basic	33,413	30,214	31,350	26,819
	Weighted-average common shares and equivalents outstanding - diluted	33,413	30,214	31,350	26,819
	We reported a net loss for each of the three and nine months ended September 30, 2013, and 2012, respectively. As a result, our basic and diluted weighted-average common shares outstanding was the same as the effect of the common share equivalents was anti-dilutive.
	The following table presents the weighted-average common share equivalents excluded from the calculation of diluted earnings per share due to their anti-dilutive effect:
		Three Months Ended September 30,		Nine Months Ended September 30,
		2013	2012	2013	2012
		(in thousands)
	Weighted-average common share equivalents excluded from diluted earnings
	per share due to their anti-dilutive effect:
	Restricted stock	805	777	857	688
	SARs	83	119	65	115
	Stock options	7	7	7	7
	Non-employee director deferred compensation	4	3	4	3
	Convertible senior notes	671	—	387	—
	Total anti-dilutive common share equivalents	1,570	906	1,320	813
	In November 2010, we issued our Convertible Notes, which give the holders the right to convert the aggregate principal amount into 2.7 million shares of our common stock at a conversion price of $42.40 per share. The Convertible Notes could be included in the dilutive earnings per share calculation using the treasury stock method if the average market share price exceeds the $42.40 conversion price during the period presented. Shares issuable upon conversion of the Convertible Notes were excluded from the diluted earnings per share calculation for the three and nine months ended September 30, 2013 as the effect would be anti-dilutive to our earnings per share. Shares issuable upon conversion of the Convertible Notes were excluded from the diluted earnings per share calculation for the three and nine months ended September 30, 2012 as the conversion price was greater than the average market price of our common stock during the period.

Divestitures_and_Discontinued_

Divestitures and Discontinued Operations	9 Months Ended
	Sep. 30, 2013
Discontinued Operations and Disposal Groups [Abstract]	'
Disposal Groups, Including Discontinued Operations, Disclosure	'
	ASSETS HELD FOR SALE, DIVESTITURES AND DISCONTINUED OPERATIONS
	Piceance Basin and NECO. In February 2013, we entered into a purchase and sale agreement with certain affiliates of Caerus Oil and Gas LLC (“Caerus”), pursuant to which we agreed to sell to Caerus our Piceance Basin, NECO and certain other non-core Colorado oil and gas properties, leasehold mineral interests and related assets. Additionally, certain firm transportation obligations and natural gas hedging positions were assumed by Caerus. On June 18, 2013, this divestiture was completed with total consideration of approximately $177.6 million, subject to customary post-closing adjustments, with an additional $17.0 million paid to our non-affiliated investor partners in our affiliated partnerships. The sale resulted in a pre-tax loss of $2.3 million. The proceeds from the asset divestiture were used to pay down our revolving credit facility and to fund a portion of our 2013 capital budget. Following the sale to Caerus, we do not have significant continuing involvement in the operations of, or cash flows from, the Piceance Basin and NECO oil and gas properties. Accordingly, the results of operations related to these assets have been separately reported as discontinued operations in the condensed consolidated statement of operations for all periods presented. The sale of our other non-core Colorado oil and gas properties did not meet the requirements to be accounted for as discontinued operations.
	Appalachian Basin. In early 2013, we developed a plan to market all of our shallow upper Devonian (non-Marcellus Shale) Appalachian Basin crude oil and natural gas properties located in West Virginia and Pennsylvania owned directly by us, as well as through our proportionate share of PDCM and our affiliated partnerships. The properties consist of approximately 3,500 gross shallow producing wells, related facilities and associated shallow leasehold acreage, limited to the upper Devonian and shallower formations. The Company will retain all zones, formations and intervals below the upper Devonian formation including the Marcellus Shale, Utica Shale and Huron Shale. We classified the related assets owned directly by us, as well as through our proportionate share of PDCM and our affiliated partnerships, as held for sale in the condensed consolidated balance sheet as of September 30, 2013. The divestiture of these assets does not meet the requirements to be accounted for as discontinued operations. In October 2013, PDCM executed a purchase and sale agreement with an unrelated third-party for the sale of these properties. The aggregate consideration is subject to customary terms and post-closing adjustments. See Note 15, Subsequent Events, for additional information on the potential sale. We expect this sale to close in the fourth quarter of 2013. However, there can be no assurance we will be successful in closing this divestiture.
	Permian Basin. In December 2011, we executed a purchase and sale agreement with COG Operating LLC (“COG”), a wholly owned subsidiary of Concho Resources Inc., an unrelated third-party, for the sale of our core Permian Basin assets for a sale price of $173.9 million, subject to customary terms and adjustments. In February 2012, the divestiture closed with total proceeds received of $189.2 million after closing adjustments. Following the sale to COG, we do not have significant continuing involvement in the operations of, or cash flows from, these assets. Accordingly, the results of operations related to the Permian assets have been separately reported as discontinued operations in the condensed consolidated statement of operations for the nine months ended September 30, 2012.
	Selected financial information related to divested and discontinued operations. The tables below set forth selected financial information related to net assets held for sale and operating results related to discontinued operations. Net assets held for sale represents the Appalachian Basin assets that are expected to be sold, net of liabilities that are expected to be assumed by the purchaser.
	The following table presents balance sheet data related to our pro rata share of these assets held for sale as of September 30, 2013:
	Balance Sheet	Net Assets Held for Sale
		(in thousands)
	Assets
	Properties and equipment	$	130,835
	Accumulated depreciation, depletion and amortization	(101,801		)
	Total Assets	29,034
	Liabilities
	Asset retirement obligation	22,788
	Net Assets	$	6,246
	The following table presents statement of operations data related to our discontinued operations for the Piceance Basin, NECO and Permian Basin divestiture:
		Three Months Ended September 30,						Nine Months Ended September 30,
	Statements of Operations - Discontinued Operations	2013			2012			2013			2012
		(in thousands)
	Revenues
	Crude oil, natural gas and NGLs sales	$	(58	)	$	7,624		$	20,398		$	25,972
	Sales from natural gas marketing	1,789			392			2,825			1,149
	Well operations, pipeline income and other	31			446			890			1,476
	Total revenues	1,762			8,462			24,113			28,597
	Costs, expenses and other
	Production costs	18			4,959			7,975			17,743
	Cost of natural gas marketing	1,679			338			2,673			1,010
	Depreciation, depletion and amortization	—			10,362			2,258			32,873
	Other	77			298			2,531			949
	(Gain) loss on sale of properties and equipment	1,254			—			2,330			(19,920		)
	Total costs, expenses and other	3,028			15,957			17,767			32,655
	Income (loss) from discontinued operations	(1,266		)	(7,495		)	6,346			(4,058		)
	Provision for income taxes	484			2,863			(2,175		)	1,590
	Income (loss) from discontinued operations, net of tax	$	(782	)	$	(4,632	)	$	4,171		$	(2,468	)
	While the reclassification of revenues and expenses related to discontinued operations for the prior period had no impact upon previously reported net earnings, the statement of operations table presents the revenues and expenses that were reclassified from the specified statement of operations line items to discontinued operations.

Transactions_with_Affiliates_a

Transactions with Affiliates and Other Related Parties	9 Months Ended
	Sep. 30, 2013
Related Party Transactions [Abstract]	'
Related Party Transactions Disclosure	'
	TRANSACTIONS WITH AFFILIATES AND OTHER RELATED PARTIES
	PDCM and Affiliated Partnerships. Our Gas Marketing segment markets the natural gas produced by PDCM and our affiliated partnerships in the Eastern operating region.
	Amounts due from/to the affiliated partnerships have historically been primarily related to derivative positions and, to a lesser extent, unbilled well lease operating expenses, and costs resulting from audit and tax preparation services. Previously, we had entered into derivative instruments on behalf of our affiliated partnerships for a percentage of their estimated production. In June 2013, all remaining derivative positions designated to our affiliated partnerships were liquidated prior to settlement. As a result, there were no amounts due from/to our affiliated partnerships related to derivative positions as of September 30, 2013.
	The following table presents amounts included in our condensed consolidated statements of operations related to the marketing of natural gas on behalf of PDCM and our affiliated partnerships:
		Three Months Ended September 30,				Nine Months Ended September 30,
	Statement of Operations	2013		2012		2013		2012
		(in thousands)
	PDCM:
	Sales from natural gas marketing	$	4,774	$	2,894	$	12,742	$	7,459
	Cost of natural gas marketing	4,680		2,838		12,492		7,313
	Affiliated Partnerships:
	Sales from natural gas marketing	348		145		931		368
	Cost of natural gas marketing	341		142		913		360
	We provide certain well operating and administrative services for PDCM. Amounts billed to PDCM for these services were $3.6 million and $10.4 million in the three and nine months ended September 30, 2013, respectively, compared to $3.0 million and $9.2 million in the three and nine months ended September 30, 2012. Our statements of operations include only our proportionate share of these billings. The following table presents the statement of operations line item in which our proportionate share is recorded and the amount for each of the periods presented:
		Three Months Ended September 30,				Nine Months Ended September 30,
	Statement of Operations Line Item	2013		2012		2013		2012
		(in thousands)
	Production costs	$	1,068	$	1,022	$	3,121	$	3,080
	Exploration expense	127		110		366		357
	General and administrative expense	584		370		1,716		1,168

Business_Segments

Business Segments	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segment Reporting Disclosure	'
	BUSINESS SEGMENTS
	We separate our operating activities into two segments: (1) Oil and Gas Exploration and Production and (2) Gas Marketing. All material inter-company accounts and transactions between segments have been eliminated.
	Oil and Gas Exploration and Production. Our Oil and Gas Exploration and Production segment includes all of our crude oil and natural gas properties. The segment represents revenues and expenses from the production and sale of crude oil, natural gas and NGLs. Segment revenue includes crude oil, natural gas and NGLs sales, commodity price risk management, net and well operation and pipeline income. Segment income (loss) consists of segment revenue less production cost, exploration expense, impairment of crude oil and natural gas properties, direct general and administrative expense and depreciation, depletion and amortization expense.
	Gas Marketing. Our Gas Marketing segment purchases, aggregates and resells natural gas produced by us and others. Segment income (loss) primarily represents sales from natural gas marketing and direct interest income, less costs of natural gas marketing and direct general and administrative expense.
	Unallocated amounts. Unallocated income includes corporate general administrative expense, corporate depreciation, depletion and amortization expense, interest income and interest expense.
	The following tables present our segment information:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013			2012
		(in thousands)
	Segment revenues:
	Oil and gas exploration and production	$	60,170		$	21,542		$	221,552		$	192,294
	Gas marketing	16,946			11,178			48,695			31,172
	Total revenues	$	77,116		$	32,720		$	270,247		$	223,466
	Segment loss before income taxes:
	Oil and gas exploration and production	$	4,573		$	(16,266	)	$	27,243		$	76,852
	Gas marketing	(181		)	(82		)	(233		)	331
	Unallocated	(29,765		)	(26,931		)	(89,537		)	(80,187		)
	Loss before income taxes	$	(25,373	)	$	(43,279	)	$	(62,527	)	$	(3,004	)
		September 30, 2013			December 31, 2012
		(in thousands)
	Segment assets:
	Oil and gas exploration and production	$	1,874,679		$	1,723,011
	Gas marketing	35,532			11,090
	Unallocated	71,718			92,747
	Assets held for sale	29,034			—
	Total assets	$	2,010,963		$	1,826,848
	Assets held for sale as of September 30, 2013 relate to our oil and gas exploration and production segment. We do not expect the divestiture of these assets to have a material impact on our financial condition and results of operations.

Subsequent_Event_Subsequent_Ev

Subsequent Event Subsequent Event (Notes)	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]	'
Subsequent Events [Text Block]	'
	SUBSEQUENT EVENTS
	On October 8, 2013, PDCM executed a purchase and sale agreement with an unrelated third-party pursuant to which PDCM agreed to sell its shallow upper Devonian (non-Marcellus Shale) Appalachian Basin crude oil and natural gas properties for aggregate consideration of approximately $18.8 million, of which our proportionate share is $6.2 million, after pre-closing adjustments. The properties consist of approximately 3,500 gross shallow producing wells, related facilities and associated shallow leasehold acreage, limited to the upper Devonian and shallower formations. The aggregate cash consideration is subject to customary terms and post-closing adjustments and by certain firm transportation obligations that will be assumed by the buyer. Concurrent with the closing of the transaction, our $6.7 million irrevocable standby letter of credit and related obligations will be novated to the buyer. We expect this sale to close in the fourth quarter of 2013. However, there can be no assurance we will be successful in closing this divestiture.

Significant_Accounting_Policie

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Consolidation, Policy	'
	The accompanying unaudited condensed consolidated financial statements include the accounts of PDC, our wholly owned subsidiaries, and our proportionate share of PDC Mountaineer, LLC ("PDCM") and our 21 affiliated partnerships. Pursuant to the proportionate consolidation method, our accompanying condensed consolidated financial statements include our pro rata share of assets, liabilities, revenues and expenses of the entities which we proportionately consolidate. All material intercompany accounts and transactions have been eliminated in consolidation.
Basis of Accounting, Policy	'
	In our opinion, the accompanying condensed consolidated financial statements contain all adjustments (consisting of only normal recurring adjustments) necessary for a fair presentation of our financial statements for interim periods in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the SEC. Accordingly, pursuant to such rules and regulations, certain notes and other financial information included in audited financial statements have been condensed or omitted. The information presented in this Quarterly Report on Form 10-Q should be read in conjunction with our audited consolidated financial statements and notes thereto included in our 2012 Form 10-K. Our results of operations and cash flows for the three and nine months ended September 30, 2013 are not necessarily indicative of the results to be expected for the full year or any other future period.
Reclassification, Policy	'
	Certain reclassifications have been made to prior period financial statements to conform to the current year presentation. These reclassifications had no impact on previously reported cash flows, net income, earnings per share or shareholders' equity.
Accounting Standards Recently Adopted	'
	Recently Adopted Accounting Standard
	On January 1, 2013, we adopted changes issued by the Financial Accounting Standards Board ("FASB") regarding the disclosure of offsetting assets and liabilities. These changes require an entity to disclose both gross and net information about both instruments and transactions eligible for offset in the statement of financial position and instruments and transactions subject to an enforceable master netting arrangement or similar agreement. The enhanced disclosures enable users of an entity’s financial statements to understand and evaluate the effect or potential effect of master netting arrangements on the entity’s financial position, including the effect or potential effect of rights of setoff associated with certain financial instruments and derivative instruments. Adoption of these changes had no impact on the condensed consolidated financial statements, except for additional disclosures.
Earnings Per Share, Policy	'
	Basic earnings per share is computed by dividing net earnings by the weighted-average number of common shares outstanding for the period. Diluted earnings per share is similarly computed except that the denominator includes the effect, using the treasury stock method, of unvested restricted stock, outstanding SARs, stock options, Convertible Notes and shares held pursuant to our non-employee director deferred compensation plan, if including such potential shares of common stock is dilutive.

Fair_Value_Measurements_and_Di1

Fair Value Measurements and Disclosures (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	'
	Our fixed-price swaps, basis swaps and physical purchases are included in Level 2 and our crude oil and natural gas collars, natural gas calls and physical sales are included in Level 3. The following table presents, for each applicable level within the fair value hierarchy, our derivative assets and liabilities, including both current and non-current portions, measured at fair value on a recurring basis:
		September 30, 2013												December 31, 2012
		Significant Other				Significant				Total				Significant Other				Significant		Total
		Observable				Unobservable								Observable				Unobservable
		Inputs				Inputs								Inputs				Inputs
		(Level 2)				(Level 3)								(Level 2)				(Level 3)
		(in thousands)
	Assets:
	Commodity-based derivative contracts	$	12,328			$	3,060			$	15,388			$	42,788			$	15,734	$	58,522
	Basis protection derivative contracts	182				12				194				387				16		403
	Total assets	12,510				3,072				15,582				43,175				15,750		58,925
	Liabilities:
	Commodity-based derivative contracts	17,293				2,340				19,633				9,839				2,081		11,920
	Basis protection derivative contracts	1,563				—				1,563				16,656				—		16,656
	Total liabilities	18,856				2,340				21,196				26,495				2,081		28,576
	Net asset (liability)	$	(6,346	)		$	732			$	(5,614	)		$	16,680			$	13,669	$	30,349
Fair Value Assets and Liabilities Unobservable Input Reconciliation	'
	The following table presents a reconciliation of our Level 3 assets measured at fair value:
			Three Months Ended September 30,								Nine Months Ended September 30,
			2013				2012				2013				2012
			(in thousands)
	Fair value, net asset, beginning of period		$	3,904			$	28,600			$	13,669			$	22,107
	Changes in fair value included in statement of operations line item:
	Commodity price risk management gain (loss), net		(3,111		)		(9,055		)		(3,008		)		6,098
	Sales from natural gas marketing		11				(4		)		16				35
	Changes in fair value included in balance sheet line item:
	Accounts payable affiliates (1)		—				(93		)		—				(240		)
	Settlements included in statement of operations line items:
	Commodity price risk management gain (loss), net		(66		)		(3,900		)		(5,545		)		(12,357		)
	Sales from natural gas marketing		(6		)		(10		)		(34		)		(105		)
	Income (loss) from discontinued operations, net of tax		—				—				(4,366		)		—
	Fair value, net asset end of period		$	732			$	15,538			$	732			$	15,538
	Changes in unrealized gains (losses) relating to assets (liabilities) still held
	as of period-end, included in statement of operations line item:
	Commodity price risk management gain (loss), net		$	(3,333	)		$	(8,169	)		$	(5,362	)		$	2,577
	Sales from natural gas marketing		(5		)		(13		)		4				(1		)
	Total		$	(3,338	)		$	(8,182	)		$	(5,358	)		$	2,576
	__________
	-1	Represents the change in fair value related to derivative instruments entered into by us and designated to our affiliated partnerships.
Concentration of Risk	'
	The following table presents the counterparties that expose us to credit risk as of September 30, 2013 with regard to our derivative assets:
	Counterparty Name		Fair Value of
			Derivative Assets
			As of September 30, 2013
			(in thousands)
	JPMorgan Chase Bank, N.A. (1)		$	4,163
	Wells Fargo Bank, N.A. (1)		3,830
	Natixis (1)		1,637
	Bank of Montreal (1)		1,885
	BNP Paribas (1)		1,285
	Other lenders in our revolving credit facility		2,624
	Various (2)		158
	Total		$	15,582
	__________
	(1)Major lender in our revolving credit facility. See Note 7, Long-Term Debt.
	(2)Represents a total of 20 counterparties.

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments Not Designated as Hedging Instruments [Abstract]	'
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	'
	The following table presents the location and fair value amounts of our derivative instruments on the condensed consolidated balance sheets as of September 30, 2013 and December 31, 2012:
						Fair Value
	Derivatives instruments:			Balance sheet line item		September 30, 2013				31-Dec-12
						(in thousands)
	Derivative assets:	Current
		Commodity contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		$	9,067			$	47,016
		Related to affiliated partnerships (1)		Fair value of derivatives		—				4,707
		Related to natural gas marketing		Fair value of derivatives		444				302
		Basis protection contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		133				—
		Related to natural gas marketing		Fair value of derivatives		16				17
						9,660				52,042
		Non Current
		Commodity contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		5,792				6,671
		Related to natural gas marketing		Fair value of derivatives		85				203
		Basis protection contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		44				—
		Related to natural gas marketing		Fair value of derivatives		1				9
						5,922				6,883
	Total derivative assets					$	15,582			$	58,925
	Derivative liabilities:	Current
		Commodity contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		$	12,880			$	1,744
		Related to natural gas marketing		Fair value of derivatives		310				226
		Basis protection contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		1,433				14,329
		Related to affiliated partnerships (2)		Fair value of derivatives		—				2,140
						14,623				18,439
		Non Current
		Commodity contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		6,403				9,969
		Related to natural gas marketing		Fair value of derivatives		40				168
		Basis protection contracts
		Related to crude oil and natural gas sales		Fair value of derivatives		130				—
						6,573				10,137
	Total derivative liabilities					$	21,196			$	28,576
	__________
	-1	Represents derivative positions designated to our affiliated partnerships. Accordingly, our accompanying December 31, 2012 condensed consolidated balance sheet includes a corresponding payable to our affiliated partnerships representing their proportionate share of the derivative assets.
	-2	Represents derivative positions designated to our affiliated partnerships. Accordingly, our accompanying December 31, 2012 condensed consolidated balance sheet includes a corresponding receivable from our affiliated partnerships representing their proportionate share of the derivative liabilities.
	The following table presents the impact of our derivative instruments on our statements of operations:
			2013											2012
	Statement of operations line item		Reclassification				Realized and Unrealized				Total			Reclassification			Realized and Unrealized			Total
			of Realized				Gains							of Realized			Gains
			Gains (Losses)				(Losses) For							Gains (Losses)			(Losses) For
			Included in Prior Periods				the							Included in Prior Periods			the
			Unrealized				Current							Unrealized			Current
							Period										Period
			(in thousands)
	Three Months Ended September 30,
	Commodity price risk management gain (loss), net
	Realized gains (losses)		$	2,936			$	(4,461	)		$	(1,525	)	$	15,010		$	(1,915	)	$	13,095
	Unrealized losses		(2,936		)		(19,177		)		(22,113		)	(15,010		)	(30,028		)	(45,038		)
	Total commodity price risk management gain (loss), net		$	—			$	(23,638	)		$	(23,638	)	$	—		$	(31,943	)	$	(31,943	)
	Sales from natural gas marketing
	Realized gains (losses)		$	249			$	(9	)		$	240		$	386		$	15		$	401
	Unrealized losses		(249		)		(62		)		(311		)	(386		)	(404		)	(790		)
	Total sales from natural gas marketing		$	—			$	(71	)		$	(71	)	$	—		$	(389	)	$	(389	)
	Cost of natural gas marketing
	Realized gains (losses)		$	(196	)		$	8			$	(188	)	$	(364	)	$	(20	)	$	(384	)
	Unrealized gains		196				82				278			364			467			831
	Total cost of natural gas marketing		$	—			$	90			$	90		$	—		$	447		$	447
Nine Months Ended September 30,
Commodity price risk management gain (loss), net
Realized gains (losses)		$	25,273			$	(14,426	)		$	10,847		$	22,813		$	16,387		$	39,200
Unrealized gains (losses)		(25,273		)		(6,843		)		(32,116		)	(22,813		)	1,900			(20,913		)
Total commodity price risk management gain (loss), net		$	—			$	(21,269	)		$	(21,269	)	$	—		$	18,287		$	18,287
Sales from natural gas marketing
Realized gains		$	206			$	61			$	267		$	1,358		$	588		$	1,946
Unrealized gains (losses)		(206		)		546				340			(1,358		)	(428		)	(1,786		)
Total sales from natural gas marketing		$	—			$	607			$	607		$	—		$	160		$	160
Cost of natural gas marketing
Realized gains (losses)		$	(133	)		$	8			$	(125	)	$	(1,195	)	$	(652	)	$	(1,847	)
Unrealized gains (losses)		133				(414		)		(281		)	1,195			587			1,782
Total cost of natural gas marketing		$	—			$	(406	)		$	(406	)	$	—		$	(65	)	$	(65	)
All of our financial derivative agreements contain master netting provisions that provide for the net settlement of all contracts through a single payment in the event of early termination. Our fixed-price physical purchase and sale agreements that qualify as derivative contracts are not subject to master netting provisions and are not significant. We have elected not to offset the fair value positions recorded on our condensed consolidated balance sheets.
The following table reflects the impact of netting agreements on gross derivative assets and liabilities as of September 30, 2013 and December 31, 2012:
As of September 30, 2013		Derivatives instruments, recorded in condensed consolidated balance sheet, gross				Effect of master netting agreements				Derivative instruments, net
		(in thousands)
Asset derivatives:
Derivative instruments, at fair value		$	15,582			$	(11,739	)		$	3,843
Liability derivatives:
Derivative instruments, at fair value		$	21,196			$	(11,739	)		$	9,457
As of December 31, 2012		Derivatives instruments, recorded in condensed consolidated balance sheet, gross				Effect of master netting agreements				Derivative instruments, net
		(in thousands)
Asset derivatives:
Derivative instruments, at fair value		$	58,925			$	(11,437	)		$	47,488
Liability derivatives:
Derivative instruments, at fair value		$	28,576			$	(11,437	)		$	17,139

Properties_and_Equipment_Table

Properties and Equipment (Tables)	9 Months Ended
	Sep. 30, 2013
Oil and Gas Property [Abstract]	'
Property, Plant and Equipment	'
	The following table presents the components of properties and equipment, net of accumulated depreciation, depletion and amortization:
		September 30, 2013			31-Dec-12
		(in thousands)
	Properties and equipment, net:
	Crude oil and natural gas properties
	Proved	$	1,533,430		$	2,075,924
	Unproved	315,233			319,327
	Total crude oil and natural gas properties	1,848,663			2,395,251
	Pipelines and related facilities	15,749			47,786
	Equipment and other	28,780			34,858
	Land and buildings	13,612			14,935
	Construction in progress	146,921			67,217
	Gross properties and equipment	2,053,725			2,560,047
	Accumulated depreciation, depletion and amortization	(514,024		)	(943,341		)
	Properties and equipment, net	$	1,539,701		$	1,616,706
Impairment of natural gas and crude oil properties [Table Text Block]	'
	The following table presents impairment charges recorded for crude oil and natural gas properties:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013		2012
		(in thousands)
	Continuing operations:
	Impairment of proved properties	$	3,750		$	—		$	48,750	$	—
	Impairment of individually significant unproved properties	154			154			979		462
	Amortization of individually insignificant unproved properties	568			234			2,704		870
	Total continuing operations	4,472			388			52,433		1,332
	Discontinued operations:
	Amortization of individually insignificant unproved properties	—			7			3		86
	Total discontinued operations	—			7			3		86
	Total impairment of crude oil and natural gas properties	$	4,472		$	395		$	52,436	$	1,418

LongTerm_Debt_Tables

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Schedule of Long-term Debt Instruments	'
	Long-term debt consists of the following:
		September 30, 2013			31-Dec-12
		(in thousands)
	Senior notes:
	3.25% Convertible senior notes due 2016:
	Principal amount	$	115,000		$	115,000
	Unamortized discount	(10,950		)	(13,671		)
	3.25% Convertible senior notes due 2016, net of discount	104,050			101,329
	7.75% Senior notes due 2022	500,000			500,000
	Total senior notes	604,050			601,329
	Credit facilities:
	Corporate	—			49,000
	PDCM	34,750			26,250
	Total credit facilities	34,750			75,250
	PDCM second lien term loan	15,000			—
	Total debt	653,800			676,579
	Less: Current portion of long-term debt	104,050			—
	Long-term debt	$	549,750		$	676,579

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	9 Months Ended
	Sep. 30, 2013
Asset Retirement Obligation Disclosure [Abstract]	'
Schedule of Change in Asset Retirement Obligation	'
	The following table presents the changes in carrying amounts of the asset retirement obligations associated with our working interest in crude oil and natural gas properties:
		Amount
		(in thousands)
	Balance at December 31, 2012	$	62,563
	Obligations incurred with development activities	337
	Accretion expense	3,667
	Revisions in estimated cash flows	251
	Obligations discharged with divestitures of properties and asset retirements	(7,376		)
	Balance at September 30, 2013	59,442
	Less: Liabilities held for sale (1)	22,788
	Less: Current portion	1,000
	Long-term portion	$	35,654
	______________
	-1	Represents asset retirement obligations related to our assets held for sale. See Note 12, Assets Held for Sale, Divestitures and Discontinued Operations and Note 15, Subsequent Events, for additional information regarding the potential sale of these properties.

Commitments_and_Contingencies_

Commitments and Contingencies Commitments and Contigencies (Tables)	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Supply Commitment	'
	The following table presents gross volume information, including our proportionate share of PDCM, related to our long-term firm transportation, sales and processing agreements for pipeline capacity:
		For the Twelve Months Ending September 30,
	Area	2014		2015		2016		2017		2018 and		Total		Expiration
										Through				Date
										Expiration
	Volume (MMcf)
	West Virginia	21,428		22,868		24,874		24,862		149,603		243,635		January 31, 2026
	Utica Shale	2,282		2,738		2,738		2,738		15,966		26,462		July 22, 2023
	Total	23,710		25,606		27,612		27,600		165,569		270,097
	Dollar commitment	$	9,601	$	10,056	$	10,462	$	10,294	$	47,785	$	88,198
	(in thousands)

Common_Stock_Tables

Common Stock (Tables)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan	'
	The following table provides a summary of the impact of our outstanding stock-based compensation plans on the results of operations for the periods presented:
			Three Months Ended September 30,							Nine Months Ended September 30,
			2013				2012			2013			2012
			(in thousands)
	Stock-based compensation expense		$	3,040			$	2,225		$	9,991		$	6,126
	Income tax benefit		(1,161		)		(847		)	(3,816		)	(2,333		)
	Net stock-based compensation expense		$	1,879			$	1,378		$	6,175		$	3,793
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	'
	In January 2013, the Compensation Committee awarded 87,078 SARs to our executive officers. The fair value of each SAR award was estimated on the date of grant using a Black-Scholes pricing model using the following assumptions:
		Grant-Year
		2013				2012
	Expected term of award	6 years				6 years
	Risk-free interest rate	1		%		1.1		%
	Expected volatility	65.5		%		64.3		%
	Weighted-average grant date fair value per share	$	21.96			$	17.61
Schedule of Share-based Compensation, Stock Appreciation Rights Award Activity	'
	The following table presents the changes in our SARs:
		Nine Months Ended September 30,
		2013												2012
		Number of			Weighted-Average				Average Remaining Contractual		Aggregate Intrinsic			Number of		Weighted-Average		Average Remaining Contractual	Aggregate Intrinsic
		SARs			Exercise				Term (in years)		Value (in thousands)			SARs		Exercise		Term (in years)	Value (in thousands)
					Price											Price
	Outstanding beginning of year, January 1,	118,832			$	30.8			8.4		$	486		50,471		$	31.61	8.6	$	341
	Awarded	87,078			37.18				—		—			68,361		30.19		9.3	—
	Outstanding at September 30,	205,910			33.5				8.4		5,363			118,832		30.8		8.7	328
	Vested and expected to vest at September 30,	198,163			33.41				8.4		5,178			113,426		30.77		8.7	319
	Exercisable at September 30,	67,069			29.99				7.3		1,982			27,458		28.84		7.8	153
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	'
	The following table presents the changes in non-vested time-based awards for the nine months ended September 30, 2013:
		Shares			Weighted-Average
					Grant-Date
					Fair Value
	Non-vested at December 31, 2012	646,490			$	27.93
	Granted	292,548			44.56
	Vested	(265,312	)		27.53
	Forfeited	(22,507	)		31.29
	Non-vested at September 30, 2013	651,219			35.45
		As of/Year Ended September 30,
		2013				2012
		(in thousands, except per share data)
	Total intrinsic value of time-based awards vested	$	12,562			$	4,818
	Total intrinsic value of time-based awards non-vested	38,774				21,996
	Market price per common share as of September 30,	59.54				31.63
	Weighted-average grant date fair value per share	44.56				26.48
Restricted Stock Awards, Market-Based, Valuation assumptions	'
	In January 2013, the Compensation Committee awarded a total of 41,570 market-based restricted shares to our executive officers. In addition to continuous employment, the vesting of these shares is contingent on the Company's total shareholder return ("TSR"), which is essentially the Company’s stock price change including any dividends, as compared to the TSR of a set group of 16 peer companies. The shares are measured over a three-year period ending on December 31, 2015 and can result in a payout between 0% and 200% of the total shares awarded. The weighted-average grant date fair value per market-based share for these awards granted was computed using the Monte Carlo pricing model using the following assumptions:
			Nine Months Ended September 30,
			2013				2012
	Expected term of award		3 years				3 years
	Risk-free interest rate		0.4		%		0.3		%
	Expected volatility		56.6		%		65.3		%
	Weighted-average grant date fair value per share		$	49.04			$	36.54
Schedule of Nonvested Performance-based Units Activity	'
	The following table presents the change in non-vested market-based awards during nine months ended September 30, 2013:
			Shares			Weighted-Average
						Grant-Date
						Fair Value per Share
	Non-vested at December 31, 2012		40,696			$	39.22
	Granted		41,570			49.04
	Non-vested at September 30, 2013		82,266			44.18
		As of/Year Ended September 30,
		2013				2012
		(in thousands, except per share data)
	Total intrinsic value of market-based awards non-vested	$	4,898			$	2,329
	Market price per common share as of September 30,	59.54				31.63
	Weighted-average grant date fair value per share	49.04				36.54

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Schedule of Earnings Per Share Reconciliation	'
	The following table presents a reconciliation of the weighted-average diluted shares outstanding:
		Three Months Ended September 30,		Nine Months Ended September 30,
		2013	2012	2013	2012
		(in thousands)
	Weighted-average common shares outstanding - basic	33,413	30,214	31,350	26,819
	Weighted-average common shares and equivalents outstanding - diluted	33,413	30,214	31,350	26,819
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	'
	The following table presents the weighted-average common share equivalents excluded from the calculation of diluted earnings per share due to their anti-dilutive effect:
		Three Months Ended September 30,		Nine Months Ended September 30,
		2013	2012	2013	2012
		(in thousands)
	Weighted-average common share equivalents excluded from diluted earnings
	per share due to their anti-dilutive effect:
	Restricted stock	805	777	857	688
	SARs	83	119	65	115
	Stock options	7	7	7	7
	Non-employee director deferred compensation	4	3	4	3
	Convertible senior notes	671	—	387	—
	Total anti-dilutive common share equivalents	1,570	906	1,320	813

Assets_Held_for_Sale_Divestitu

Assets Held for Sale, Divestitures and Discontinued Operations (Tables)	9 Months Ended
	Sep. 30, 2013
Discontinued Operations and Disposal Groups [Abstract]	'
Schedule of Discontinued Operations	'
	The tables below set forth selected financial information related to net assets held for sale and operating results related to discontinued operations. Net assets held for sale represents the Appalachian Basin assets that are expected to be sold, net of liabilities that are expected to be assumed by the purchaser.
	The following table presents balance sheet data related to our pro rata share of these assets held for sale as of September 30, 2013:
	Balance Sheet	Net Assets Held for Sale
		(in thousands)
	Assets
	Properties and equipment	$	130,835
	Accumulated depreciation, depletion and amortization	(101,801		)
	Total Assets	29,034
	Liabilities
	Asset retirement obligation	22,788
	Net Assets	$	6,246
	The following table presents statement of operations data related to our discontinued operations for the Piceance Basin, NECO and Permian Basin divestiture:
		Three Months Ended September 30,						Nine Months Ended September 30,
	Statements of Operations - Discontinued Operations	2013			2012			2013			2012
		(in thousands)
	Revenues
	Crude oil, natural gas and NGLs sales	$	(58	)	$	7,624		$	20,398		$	25,972
	Sales from natural gas marketing	1,789			392			2,825			1,149
	Well operations, pipeline income and other	31			446			890			1,476
	Total revenues	1,762			8,462			24,113			28,597
	Costs, expenses and other
	Production costs	18			4,959			7,975			17,743
	Cost of natural gas marketing	1,679			338			2,673			1,010
	Depreciation, depletion and amortization	—			10,362			2,258			32,873
	Other	77			298			2,531			949
	(Gain) loss on sale of properties and equipment	1,254			—			2,330			(19,920		)
	Total costs, expenses and other	3,028			15,957			17,767			32,655
	Income (loss) from discontinued operations	(1,266		)	(7,495		)	6,346			(4,058		)
	Provision for income taxes	484			2,863			(2,175		)	1,590
	Income (loss) from discontinued operations, net of tax	$	(782	)	$	(4,632	)	$	4,171		$	(2,468	)
	While the reclassification of revenues and expenses related to discontinued operations for the prior period had no impact upon previously reported net earnings, the statement of operations table presents the revenues and expenses that were reclassified from the specified statement of operations line items to discontinued operations.

Transactions_with_Affiliates_a1

Transactions with Affiliates and Other Related Parties (Tables)	9 Months Ended
	Sep. 30, 2013
Related Party Transactions [Abstract]	'
Schedule of Related Party Transactions	'
	The following table presents amounts included in our condensed consolidated statements of operations related to the marketing of natural gas on behalf of PDCM and our affiliated partnerships:
		Three Months Ended September 30,				Nine Months Ended September 30,
	Statement of Operations	2013		2012		2013		2012
		(in thousands)
	PDCM:
	Sales from natural gas marketing	$	4,774	$	2,894	$	12,742	$	7,459
	Cost of natural gas marketing	4,680		2,838		12,492		7,313
	Affiliated Partnerships:
	Sales from natural gas marketing	348		145		931		368
	Cost of natural gas marketing	341		142		913		360
	We provide certain well operating and administrative services for PDCM. Amounts billed to PDCM for these services were $3.6 million and $10.4 million in the three and nine months ended September 30, 2013, respectively, compared to $3.0 million and $9.2 million in the three and nine months ended September 30, 2012. Our statements of operations include only our proportionate share of these billings. The following table presents the statement of operations line item in which our proportionate share is recorded and the amount for each of the periods presented:
		Three Months Ended September 30,				Nine Months Ended September 30,
	Statement of Operations Line Item	2013		2012		2013		2012
		(in thousands)
	Production costs	$	1,068	$	1,022	$	3,121	$	3,080
	Exploration expense	127		110		366		357
	General and administrative expense	584		370		1,716		1,168

Business_Segments_Tables

Business Segments (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Schedule of Segment Reporting Information	'
	The following tables present our segment information:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013			2012
		(in thousands)
	Segment revenues:
	Oil and gas exploration and production	$	60,170		$	21,542		$	221,552		$	192,294
	Gas marketing	16,946			11,178			48,695			31,172
	Total revenues	$	77,116		$	32,720		$	270,247		$	223,466
	Segment loss before income taxes:
	Oil and gas exploration and production	$	4,573		$	(16,266	)	$	27,243		$	76,852
	Gas marketing	(181		)	(82		)	(233		)	331
	Unallocated	(29,765		)	(26,931		)	(89,537		)	(80,187		)
	Loss before income taxes	$	(25,373	)	$	(43,279	)	$	(62,527	)	$	(3,004	)
		September 30, 2013			December 31, 2012
		(in thousands)
	Segment assets:
	Oil and gas exploration and production	$	1,874,679		$	1,723,011
	Gas marketing	35,532			11,090
	Unallocated	71,718			92,747
	Assets held for sale	29,034			—
	Total assets	$	2,010,963		$	1,826,848
	Assets held for sale as of September 30, 2013 relate to our oil and gas exploration and production segment. We do not expect the divestiture of these assets to have a material impact on our financial condition and results of operations.

Recovered_Sheet1

Nature of Operations and Basis of Presentation Additional Information (Details)	9 Months Ended
	Sep. 30, 2013
	Partnerships
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Oil and natural gas producing wells, gross	6,250
Number of Operating Segments	2
Number of Affiliated Partnerships	21

Fair_Value_Measurements_and_Di2

Fair Value Measurements and Disclosures (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013
		Fair Value	Fair Value	Fair Value	Fair Value	Fair Value	Fair Value	3.25% Convertible Senior Notes due 2016	7.75% Senior Notes due 2022
		Significant Other Observable Inputs (Level 2)	Significant Other Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)	Significant Unobservable Inputs (Level 3)	Total	Total	Rate	Rate
Assets and Liabilities at Fair Value	'	'	'	'	'	'	'	'	'
Document Period End Date	30-Sep-13	'	'	'	'	'	'	'	'
Commodity-based derivative - assets	'	$12,328,000	$42,788,000	$3,060,000	$15,734,000	$15,388,000	$58,522,000	'	'
Basis protection derivative - assets	'	182,000	387,000	12,000	16,000	194,000	403,000	'	'
Total assets	'	12,510,000	43,175,000	3,072,000	15,750,000	15,582,000	58,925,000	'	'
Commodity-based derivative - liabilities	'	17,293,000	9,839,000	2,340,000	2,081,000	19,633,000	11,920,000	'	'
Basis protection derivative - liabilities	'	1,563,000	16,656,000	0	0	1,563,000	16,656,000	'	'
Total liabilities	'	18,856,000	26,495,000	2,340,000	2,081,000	21,196,000	28,576,000	'	'
Net asset (fair value)	'	-6,346,000	16,680,000	732,000	13,669,000	-5,614,000	30,349,000	'	'
Debt Instrument, Interest Rate, Stated Percentage	'	'	'	'	'	'	'	3.25%	7.75%
3.25% convertible senior notes fair value	'	'	'	'	'	'	'	176,400,000	'
3.25% convertible senior notes fair value as a percentage of par	'	'	'	'	'	'	'	153.40%	'
7.75% senior notes fair value	'	'	'	'	'	'	'	'	$528,800,000
7.75% senior notes fair value as percentage of par	'	'	'	'	'	'	'	'	105.70%

Reconciliation_of_Level_3_Fair

Reconciliation of Level 3 Fair Value Measurements (Details) (Derivative Financial Instrument Net Assets, USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Roll-forward of Level 3 Assets	'		'		'		'
Fair Value, net assets, beginning of period	$3,904		$28,600		$13,669		$22,107
Fair Value, net assets, end of period	732		15,538		732		15,538
Changes in unrealized gains (losses) relating to assets (liabilities) still held as of period end, included in statement of operations line item;	-3,338		-8,182		-5,358		2,576
Commodity Price Risk Management (loss), net	'		'		'		'
Roll-forward of Level 3 Assets	'		'		'		'
Changes in fair value included in statement of operations line item:	-3,111		-9,055		-3,008		6,098
Settlements included in statement of operations line items:	-66		-3,900		-5,545		-12,357
Changes in unrealized gains (losses) relating to assets (liabilities) still held as of period end, included in statement of operations line item;	-3,333		-8,169		-5,362		2,577
Sales From Natural Gas Marketing	'		'		'		'
Roll-forward of Level 3 Assets	'		'		'		'
Changes in fair value included in statement of operations line item:	11		-4		16		35
Settlements included in statement of operations line items:	-6		-10		-34		-105
Changes in unrealized gains (losses) relating to assets (liabilities) still held as of period end, included in statement of operations line item;	-5		-13		4		-1
Accounts Payable Affiliates	'		'		'		'
Roll-forward of Level 3 Assets	'		'		'		'
Changes in fair value Included in blance sheet line item:	0	[1]	-93	[1]	0	[1]	-240	[1]
Income (loss) from Discontinued Operations, Net of Tax	'		'		'		'
Roll-forward of Level 3 Assets	'		'		'		'
Settlements included in statement of operations line items:	$0		$0		($4,366)		$0
[1]	Represents the change in fair value related to derivative instruments entered into by us and designated to our affiliated partnerships.

Fair_Value_Measurements_and_Di3

Fair Value Measurements and Disclosures Concentration of Risk (Details) (USD $)	Sep. 30, 2013
Concentration Risk [Line Items]	'
Fair Value of Derivative Assets	$15,582,000
Number of derivative counterparties not lenders in our revolving credit facility	20
JPMorgan Chase Bank	'
Concentration Risk [Line Items]	'
Fair Value of Derivative Assets	4,163,000	[1]
Wells Fargo Bank	'
Concentration Risk [Line Items]	'
Fair Value of Derivative Assets	3,830,000	[1]
Natixis	'
Concentration Risk [Line Items]	'
Fair Value of Derivative Assets	1,637,000	[1]
Bank of Montreal	'
Concentration Risk [Line Items]	'
Fair Value of Derivative Assets	1,885,000	[1]
BNP Paribas	'
Concentration Risk [Line Items]	'
Fair Value of Derivative Assets	1,285,000	[1]
Other Lenders in Our Credit Facility	'
Concentration Risk [Line Items]	'
Fair Value of Derivative Assets	2,624,000
Various	'
Concentration Risk [Line Items]	'
Fair Value of Derivative Assets	$158,000	[2]
[1]	Major lender in our revolving credit facility. See Note 7, Long-Term Debt.
[2]	Represents a total of 20 counterparties.

Derivative_Financial_Instrumen2

Derivative Financial Instruments Additional Information (Details)	Sep. 30, 2013
	MBbls
	MMBTU
Derivatives in Place for Anticipated Production	'
Anticipated natural gas production hedged (MMBtu)	51,305,000
Anticipated crude oil production hedged (MBbls)	7,735

Fair_Value_of_Derivative_and_B

Fair Value of Derivative and Balance Sheet Location (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Derivatives, Fair Value	'		'
Derivative Asset, Fair Value, Gross Asset	$15,582		$58,925
Derivative Liability, Fair Value, Gross Liability	21,196		28,576
Current Assets	'		'
Derivatives, Fair Value	'		'
Derivative Asset, Fair Value, Gross Asset	9,660		52,042
Non Current Assets	'		'
Derivatives, Fair Value	'		'
Derivative Asset, Fair Value, Gross Asset	5,922		6,883
Current Liabilities	'		'
Derivatives, Fair Value	'		'
Derivative Liability, Fair Value, Gross Liability	14,623		18,439
Non Current Liabilities	'		'
Derivatives, Fair Value	'		'
Derivative Liability, Fair Value, Gross Liability	6,573		10,137
Commodity Contracts Related to Natural Gas and Crude Oil Sales | Current Assets	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	9,067		47,016
Commodity Contracts Related to Natural Gas and Crude Oil Sales | Non Current Assets	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	5,792		6,671
Commodity Contracts Related to Natural Gas and Crude Oil Sales | Current Liabilities	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	12,880		1,744
Commodity Contracts Related to Natural Gas and Crude Oil Sales | Non Current Liabilities	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	6,403		9,969
Commodity Contracts Related to Affiliated Partnership | Current Assets	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	0	[1]	4,707	[1]
Commodity Contracts Related to Natural Gas Marketing | Current Assets	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	444		302
Commodity Contracts Related to Natural Gas Marketing | Non Current Assets	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	85		203
Commodity Contracts Related to Natural Gas Marketing | Current Liabilities	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	310		226
Commodity Contracts Related to Natural Gas Marketing | Non Current Liabilities	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	40		168
Basis Protection Contracts Related to Natural Gas and Crude Oil Sales | Current Assets	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	133		0
Basis Protection Contracts Related to Natural Gas and Crude Oil Sales | Non Current Assets	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	44		0
Basis Protection Contracts Related to Natural Gas and Crude Oil Sales | Current Liabilities	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	1,433		14,329
Basis Protection Contracts Related to Natural Gas and Crude Oil Sales | Non Current Liabilities	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	130		0
Basis Protection Contracts Related to Natural Gas Marketing | Current Assets	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	16		17
Basis Protection Contracts Related to Natural Gas Marketing | Non Current Assets	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	1		9
Basis Protection Contracts Related to Affiliated Partnerships | Current Liabilities	'		'
Derivatives, Fair Value	'		'
Fair Value of Derivatives	$0	[2]	$2,140	[2]
[1]	Represents derivative positions designated to our affiliated partnerships. Accordingly, our accompanying December 31, 2012 condensed consolidated balance sheet includes a corresponding payable to our affiliated partnerships representing their proportionate share of the derivative assets.
[2]	Represents derivative positions designated to our affiliated partnerships. Accordingly, our accompanying December 31, 2012 condensed consolidated balance sheet includes a corresponding receivable from our affiliated partnerships representing their proportionate share of the derivative liabilities

Impact_of_Derivative_Instrumen

Impact of Derivative Instruments on Statement of Operations (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
Commodity Price Risk Management (loss), net	'	'	'	'
Derivative [Line Items]	'	'	'	'
Realized gains	($1,525)	$13,095	$10,847	$39,200
Unrealized gains (Losses)	-22,113	-45,038	-32,116	-20,913
Total derivatives gain (loss)	-23,638	-31,943	-21,269	18,287
Sales From Natural Gas Marketing	'	'	'	'
Derivative [Line Items]	'	'	'	'
Realized gains	240	401	267	1,946
Unrealized gains (Losses)	-311	-790	340	-1,786
Total derivatives gain (loss)	-71	-389	607	160
Cost of Natural Gas Marketing	'	'	'	'
Derivative [Line Items]	'	'	'	'
Realized gains	-188	-384	-125	-1,847
Unrealized gains (Losses)	278	831	-281	1,782
Total derivatives gain (loss)	90	447	-406	-65
Reclassification of Realized Gains (Losses) Included in Prior Periods Unrealized | Commodity Price Risk Management (loss), net	'	'	'	'
Derivative [Line Items]	'	'	'	'
Realized gains	2,936	15,010	25,273	22,813
Unrealized gains (Losses)	-2,936	-15,010	-25,273	-22,813
Total derivatives gain (loss)	0	0	0	0
Reclassification of Realized Gains (Losses) Included in Prior Periods Unrealized | Sales From Natural Gas Marketing	'	'	'	'
Derivative [Line Items]	'	'	'	'
Realized gains	249	386	206	1,358
Unrealized gains (Losses)	-249	-386	-206	-1,358
Total derivatives gain (loss)	0	0	0	0
Reclassification of Realized Gains (Losses) Included in Prior Periods Unrealized | Cost of Natural Gas Marketing	'	'	'	'
Derivative [Line Items]	'	'	'	'
Realized gains	-196	-364	-133	-1,195
Unrealized gains (Losses)	196	364	133	1,195
Total derivatives gain (loss)	0	0	0	0
Realized and Unrealized Gains (Losses) for the Current Period | Commodity Price Risk Management (loss), net	'	'	'	'
Derivative [Line Items]	'	'	'	'
Realized gains	-4,461	-1,915	-14,426	16,387
Unrealized gains (Losses)	-19,177	-30,028	-6,843	1,900
Total derivatives gain (loss)	-23,638	-31,943	-21,269	18,287
Realized and Unrealized Gains (Losses) for the Current Period | Sales From Natural Gas Marketing	'	'	'	'
Derivative [Line Items]	'	'	'	'
Realized gains	-9	15	61	588
Unrealized gains (Losses)	-62	-404	546	-428
Total derivatives gain (loss)	-71	-389	607	160
Realized and Unrealized Gains (Losses) for the Current Period | Cost of Natural Gas Marketing	'	'	'	'
Derivative [Line Items]	'	'	'	'
Realized gains	8	-20	8	-652
Unrealized gains (Losses)	82	467	-414	587
Total derivatives gain (loss)	$90	$447	($406)	($65)

Derivative_Financial_Instrumen3

Derivative Financial Instruments Impact of Netting Agreements (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Derivative Asset:	'	'
Derivative assets, gross	$15,582	$58,925
Effect of master netting agreements	-11,739	-11,437
Derivative asset, net	3,843	47,488
Derivative Liability:	'	'
Derivative liability, gross	21,196	28,576
Effect of master netting agreements	-11,739	-11,437
Derivative liability, net	$9,457	$17,139

Properties_and_Equipment_Detai

Properties and Equipment (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Property, Plant and Equipment	'	'
Proved Natural Gas and Crude Oil Properties	$1,533,430	$2,075,924
Unproved Natural Gas and Crude Oil Properties	315,233	319,327
Total Natural Gas and Crude Oil Properties	1,848,663	2,395,251
Pipelines and Related Facilities	15,749	47,786
Transportation and Other Equipment	28,780	34,858
Land and Buildings	13,612	14,935
Construction in Progress	146,921	67,217
Gross Propertis and Equipment	2,053,725	2,560,047
Accumulated Depreciation, Depletion and Amortization	-514,024	-943,341
Property, Plant and Equipment, Net	1,539,701	1,616,706
Divestitures and Assets Held for Sale	'	'
Property, Plant and Equipment	'	'
Gross Propertis and Equipment	780,000	'
Accumulated Depreciation, Depletion and Amortization	$566,400	'

Impairment_of_Natural_Gas_and_

Impairment of Natural Gas and Crude Oil Properties (Details) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Mar. 31, 2013
					Divestitures and Assets Held for Sale	Divestitures and Assets Held for Sale
Continuing Operations:	'	'	'	'	'	'
Impairment of proved properties	$3,750	$0	$48,750	$0	$3,800	$45,000
Impairment of significantly unproved properties	154	154	979	462	'	'
Amortization of Individually Insignificant Unproved Properties	568	234	2,704	870	'	'
Total continuing operations	4,472	388	52,433	1,332	'	'
Discontinued operations:	'	'	'	'	'	'
Impairment of proved properties	0	7	3	86	'	'
Total discontinued operations	0	7	3	86	'	'
Total impairment of crude oil and natural gas properties	$4,472	$395	$52,436	$1,418	'	'

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Income Tax Disclosure [Abstract]	'	'	'	'	'
Effective Income Tax Rate, Continuing Operations	40.00%	35.30%	36.60%	31.10%	'
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$0.20	'	$0.20	'	$0.20

Schedule_of_LongTerm_Debt_Deta

Schedule of Long-Term Debt (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Instrument	'	'
Total senior notes	$604,050	$601,329
Total credit facilities	34,750	75,250
PDCM second lien term loan	15,000	0
Total Debt	653,800	676,579
Current portion of long-term debt	104,050	0
Long-term debt	549,750	676,579
3.25% Convertible Senior Notes due 2016	'	'
Debt Instrument	'	'
Principal amount	115,000	115,000
Unamortized discount	-10,950	-13,671
3.25% Convertible senior notes due 2016, net of discount	104,050	101,329
7.75% Senior Notes due 2022	'	'
Debt Instrument	'	'
Senior Notes	500,000	500,000
Revolving Credit Facility	'	'
Debt Instrument	'	'
Corporate Line of Credit Outstanding	0	49,000
PDCM Credit Facility	'	'
Debt Instrument	'	'
PDCM Line of Credit Outstanding	$34,750	$26,250

LongTerm_Debt_Additional_Infor

Long-Term Debt Additional Information (Details) (USD $)

0 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

0 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

9 Months Ended

12 Months Ended

Jul. 02, 2013

Sep. 30, 2013

Dec. 31, 2012

15-May-16

Nov. 15, 2010

Sep. 30, 2013

Sep. 30, 2013

Oct. 15, 2022

Oct. 03, 2012

Sep. 30, 2013

21-May-18

Oct. 05, 2010

Sep. 30, 2013

Apr. 30, 2017

Apr. 30, 2010

Sep. 30, 2013

30-May-13

Dec. 31, 2012

Oct. 31, 2017

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2013

Dec. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

3.25% Convertible Senior Notes due 2016

3.25% Convertible Senior Notes due 2016

3.25% Convertible Senior Notes due 2016

3.25% Convertible Senior Notes due 2016

7.75% Senior Notes due 2022

7.75% Senior Notes due 2022

7.75% Senior Notes due 2022

Revolving Credit Facility

Revolving Credit Facility

Revolving Credit Facility

PDCM Credit Facility

PDCM Credit Facility

PDCM Credit Facility

PDCM Credit Facility

PDCM Credit Facility

PDCM Second Lien Term Loan

PDCM Second Lien Term Loan

RNG Credit Facility

First Payment

First Payment

Second Payment

Second Payment

Alternate Base Rate

LIBOR

Rate

Rate

Rate

Rate

Rate

Rate

3.25% Convertible Senior Notes due 2016

7.75% Senior Notes due 2022

3.25% Convertible Senior Notes due 2016

7.75% Senior Notes due 2022

PDCM Second Lien Term Loan

PDCM Second Lien Term Loan

Debt Instrument

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Interest Rate, Stated Percentage

'

'

'

'

'

3.25%

3.25%

'

'

7.75%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Issuance Date

2-Jul-13

'

'

'

15-Nov-10

'

'

'

3-Oct-12

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Maturity Date

'

'

'

15-May-16

'

'

'

15-Oct-22

'

'

'

'

'

'

'

'

'

'

31-Oct-17

'

'

'

'

'

'

'

'

Debt Instrument, Frequency of Periodic Payment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'May 15

'April 15

'November 15

'October 15

'

'

3.25% Convertible Debt, Liability Component ($)

'

'

'

'

$94,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Effective Interest Rate on Convertible Debt

'

'

'

'

'

'

7.40%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Terms of Conversion Feature

'

'

'

'

'

'

'Upon conversion, the Convertible Notes may be settled, at our election, in shares of our common stock, cash or a combination of cash and shares of our common stock. We have initially elected a net-settlement method to satisfy our conversion obligation, which allows us to settle the principal amount of the Convertible Notes in cash and to settle the excess conversion value in shares, as well as cash in lieu of fractional shares.

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible Note Stock Price Trigger

'

'

'

'

'

$55.12

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible Note Threshold Percentage of Stock Price Trigger

'

'

'

'

'

130.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

PDC Energy Stock Price

'

'

'

'

'

$59.54

$59.54

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Convertible Note, If-converted Value in Excess of Principal

'

'

'

'

'

46,488,196.39

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Initiation Date

'

'

'

'

'

'

'

'

'

'

'

5-Nov-10

'

'

30-Apr-10

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Maximum Borrowing Capacity ($)

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000,000

'

'

400,000,000

'

'

'

75,000,000

'

'

'

'

'

'

'

Line of Credit Facility, Current Borrowing Capacity ($)

'

'

'

'

'

'

'

'

'

'

'

'

450,000,000

'

'

'

80,000,000

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Expiration Date

'

'

'

'

'

'

'

'

'

'

21-May-18

'

'

30-Apr-17

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Covenant Description

'

'

'

'

'

'

'

'

'

'

'

'

'The revolving credit facility contains covenants customary for agreements of this type, with the most restrictive being certain financial tests and requirements to maintain certain financial ratios on a quarterly basis. The financial tests and ratios, as defined per the revolving credit facility, include requirements to maintain a minimum current ratio of 1.00 to 1.00 and to not exceed a maximum leverage ratio of 4.25 to 1.00.

'

'

'The credit facility contains covenants customary for agreements of this type, with the most restrictive being certain financial tests and financial ratios that must be met on a quarterly basis. The financial tests and ratios, as defined by the credit facility, include requirements to maintain a minimum current ratio of 1.0 to 1.0, not to exceed a debt to EBITDAX ratio of 4.25 to 1.0 (declining to 4.0 to 1.0 on July 1, 2014) and to maintain a minimum interest coverage ratio of 2.5 to 1.0

'

'

'

'The Term Loan Agreement contains financial covenants that must be met on a quarterly basis, including requirements to maintain a minimum current ratio of 1.0 to 1.0, not to exceed a debt to EBITDAX ratio of 4.5 to 1.0, to maintain a minimum interest coverage ratio of 2.25 to 1.0 and not to exceed a present value of future net revenues to total debt ratio of 1.50 to 1.00.

'

'

'

'

'

'

'

PDC Irrevocable Standby Letter of Credit ($)

'

'

'

'

'

'

'

'

'

'

'

'

18,500,000

'

'

'

'

'

'

'

11,800,000

'

'

'

'

'

'

Line of Credit Facility, Remaining Borrowing Capacity ($)

'

'

'

'

'

'

'

'

'

'

'

'

431,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted Average Interest Rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.60%

'

3.50%

'

8.50%

'

'

'

'

'

'

'

Proportionate Share of PDCM Credit Facility ($)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

40,000,000

'

'

'

'

'

'

'

'

'

'

PDCM second lien term loan

'

$15,000,000

$0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$30,000,000

'

'

'

'

'

'

'

Margin on Variable Interest Rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7.00%

6.00%

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012	Dec. 31, 2012
Asset Retirement Obligation, Roll Forward Analysis	'		'	'
Balance at December 31, 2012	$62,563		'	'
Obligations incurred with development activities	337		'	'
Accretion expense	3,667		2,839	'
Revision in estimated cash flows	251		'	'
Obligations discharged with disposal of properties and asset retirements	-7,376		'	'
Balance at September 30, 2013	59,442		'	'
Liabilities held for sale	22,788	[1]	'	'
Less current portion	1,000		'	'
Long-term portion	$35,654		'	$61,563
[1]	Represents asset retirement obligations related to our assets held for sale. See Note 12, Assets Held for Sale, Divestitures and Discontinued Operations and Note 15, Subsequent Events, for additional information regarding the potential sale of these properties.

Commitments_and_Contingencies_1

Commitments and Contingencies Commitments and Contigencies (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	270,097
Dollar Commitment ($ in thousands)	88,198
West Virginia	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	243,635
Utica Shale	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	26,462
Shallow Upper Devonian properties	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	34,572
Dollar Commitment ($ in thousands)	16,500
First Year Commitment	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	23,710
Dollar Commitment ($ in thousands)	9,601
First Year Commitment | West Virginia	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	21,428
First Year Commitment | Utica Shale	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	2,282
Second Year Commitment	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	25,606
Dollar Commitment ($ in thousands)	10,056
Second Year Commitment | West Virginia	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	22,868
Second Year Commitment | Utica Shale	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	2,738
Third Year Commitment	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	27,612
Dollar Commitment ($ in thousands)	10,462
Third Year Commitment | West Virginia	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	24,874
Third Year Commitment | Utica Shale	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	2,738
Fourth Year Commitment	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	27,600
Dollar Commitment ($ in thousands)	10,294
Fourth Year Commitment | West Virginia	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	24,862
Fourth Year Commitment | Utica Shale	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	2,738
commitments 5 years and beyond	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	165,569
Dollar Commitment ($ in thousands)	47,785
commitments 5 years and beyond | West Virginia	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	149,603
commitments 5 years and beyond | Utica Shale	'
Supply Commitment	'
Oil and Gas Delivery Commitments Volumes (MMcf)	15,966
Supply Contract Expiration Date | West Virginia	'
Supply Commitment	'
Supply Commitments Contract Expiration Date	31-Jan-26
Supply Contract Expiration Date | Utica Shale	'
Supply Commitment	'
Supply Commitments Contract Expiration Date	22-Jul-23

Commitments_and_Contingencies_2

Commitments and Contingencies Additional information (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'	'
Accrued Environmental Liabilities	$5.60	$8.40
Maximum Annual Repurchase Obligation	$4.20	'

Common_Stock_Stockholders_Equi

Common Stock Stockholders' Equity Note (Details) (USD $)	9 Months Ended			3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013
				August 2013 Common Stock Issuance
Shares of Common Stock	'	'	'	'
Number of shares issued in public offering of common stock	'	'	'	5,175,000
Common stock, par value	$0.01	'	$0.01	$0.01
Public offering of common stock, price per share	'	'	'	$53.37
Common shares outstanding at September 30, 2013	'	'	'	35,650,758
Net proceeds from public offering of common stock	$275,847,000	$164,496,000	'	$275,800,000
Component of proceeds from public offering included in common shares-par value	357,000	'	303,000	51,750
Component of proceeds from public offering included in additional paid-in capital	$670,990,000	'	$387,494,000	$275,800,000

Stocked_Based_Compensation_Sum

Stocked Based Compensation Summary (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
Employee Service Share-based Compensation, Allocation of Recognized Period Costs	'	'	'	'
Stock-based compensation expense	$3,040	$2,225	$9,991	$6,126
Income tax benefit	-1,161	-847	-3,816	-2,333
Net stock-based compensation expense	$1,879	$1,378	$6,175	$3,793

SARs_Fair_Value_Assumptions_De

SARs Fair Value Assumptions (Details) (Stock Appreciation Rights (SARs), USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
	Rate	Rate
Stock Appreciation Rights (SARs)	'	'
Share-based Compensation Arrangement by Share-based Payment Award	'	'
Expected term of award	'6 years	'6 years
Risk-free interest rate	1.00%	1.10%
Expected Volatility	65.50%	64.30%
Weighted-average grant date fair value per share	$21.96	$17.61

Schedule_of_Changes_in_SARs_De

Schedule of Changes in SARs (Details) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	'The SARs vest ratably over a three-year period and may be exercised at any point after vesting through 10 years from the date of issuance. Pursuant to the terms of the awards, upon exercise, the executive officers will receive, in shares of common stock, the excess of the market price of the award on the date of exercise over the market price of the award on the date of issuance.	'	'	'
Stock Appreciation Rights (SARs)	'	'	'	'
Number of SARs	'	'	'	'
Outstanding beginning of year, January 1,	118,832	50,471	50,471	'
Awarded	87,078	68,361	'	'
Outstanding at September 30,	205,910	118,832	118,832	50,471
Vested and expected to vest at September 30,	198,163	113,426	'	'
Exercisable at September 30,	67,069	27,458	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	'	'	'	'
Outstanding beginning of year, January 1,	$30.80	$31.61	$31.61	'
Awarded	$37.18	$30.19	'	'
Outstanding at September 30,	$33.50	$30.80	$30.80	$31.61
Vested and expected to vest at September 30,	$33.41	$30.77	'	'
Exercisable at September 30,	$29.99	$28.84	'	'
Weighted-Average Remaining Contractual Term (in years)	'	'	'	'
Outstanding beginning of year, January 1,	'8 years 4 months 16 days	'8 years 8 months 30 days	'8 years 4 months 7 days	'8 years 7 months 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Awarded, Weighted Average Remaining Contractual Term	'	'9 years 3 months 0 days	'	'
Outstanding at September 30,	'8 years 4 months 16 days	'8 years 8 months 30 days	'8 years 4 months 7 days	'8 years 7 months 6 days
Vested and expected to vest at September 30,	'8 years 4 months 7 days	'8 years 8 months 30 days	'	'
Exercisable at September 30,	'7 years 3 months 21 days	'7 years 9 months 0 days	'	'
Share based compesation aggregate intrinsic value	'	'	'	'
Outstanding beginning of year, January 1,	$5,363,000	$328,000	$486,000	$341,000
Awarded	0	0	'	'
Outstanding at September 30,	5,363,000	328,000	486,000	341,000
Vested and expected to vest at September 30,	5,178,000	319,000	'	'
Exercisable at September 30,	1,982,000	153,000	'	'
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$2,000,000	'	'	'
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	'2 years 0 months 0 days	'	'	'

Schedule_of_Changes_in_Restric

Schedule of Changes in Restricted Stock - TIme Based Awards (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	'The SARs vest ratably over a three-year period and may be exercised at any point after vesting through 10 years from the date of issuance. Pursuant to the terms of the awards, upon exercise, the executive officers will receive, in shares of common stock, the excess of the market price of the award on the date of exercise over the market price of the award on the date of issuance.	'
Restricted stock	'	'
Share-based Compensation Arrangement by Share-based Payment Award	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	'The fair value of the time-based restricted shares is amortized ratably over the requisite service period, primarily three or four years. The time-based shares vest ratably on each annual anniversary following the grant date if the participant is continuously employed.	'
Time based shares granted to executives	103,050	'
Number of Shares	'	'
Outstanding beginning of year, January 1,	646,490	'
Granted	292,548	'
Vested	-265,312	'
Forfeited	-22,507	'
Outstanding at September 30,	651,219	'
Weighted-Average Grant-Date Fair Value	'	'
Outstanding at beginning of year, January 1,	$27.93	'
Weighted-average grant date fair value per share	$44.56	$26.48
Vested	$27.53	'
Forfeited	$31.29	'
Outstanding at September 30,	$35.45	'
Total intrinsic value of time based awards vested	$12,562,000	$4,818,000
Total intrinsic value of time-based awards non-vested	38,774,000	21,996,000
Market price per common share as of September 30,	$59.54	$31.63
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$16,800,000	'
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	'2 years 1 month 24 days	'

Restricted_Stock_Market_Based_

Restricted Stock - Market Based Awards Fair Value Assumptions (Details) (Restricted Stock - Market Based Awards, USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
	Rate	Rate
Restricted Stock - Market Based Awards	'	'
Share-based Compensation Arrangement by Share-based Payment Award	'	'
Expected term of award	'3 years	'3 years
Risk-free interest rate	0.40%	0.30%
Expected Volatility	56.60%	65.30%
Weighted-average grant date fair value per share	$49.04	$36.54

Schedule_of_Changes_in_Restric1

Schedule of Changes in Restricted Stock - Market Based Awards (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	'The SARs vest ratably over a three-year period and may be exercised at any point after vesting through 10 years from the date of issuance. Pursuant to the terms of the awards, upon exercise, the executive officers will receive, in shares of common stock, the excess of the market price of the award on the date of exercise over the market price of the award on the date of issuance.	'
Restricted Stock - Market Based Awards	'	'
Share-based Compensation Arrangement by Share-based Payment Award	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	'The fair value of the market-based restricted shares is amortized ratably over the requisite service period, primarily three years. The market-based shares vest if the participant is continuously employed throughout the performance period and the market-based performance measure is achieved, with a maximum vesting period of three to five years. All compensation cost related to the market-based awards will be recognized if the requisite service period is fulfilled, even if the market condition is not achieved.	'
Time based shares granted to executives	41,570	'
Number of Shares	'	'
Outstanding beginning of year, January 1,	40,696	'
Granted	41,570	'
Outstanding at September 30,	82,266	'
Weighted-Average Grant-Date Fair Value	'	'
Outstanding at beginning of year, January 1,	$39.22	'
Weighted-average grant date fair value per share	$49.04	$36.54
Outstanding at September 30,	$44.18	'
Total intrinsic value of market-based awards non-vested	$4,898,000	$2,329,000
Market price per common share as of September 30,	$59.54	$31.63
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$2,000,000	'
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	'2 years 0 months 0 days	'

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Nov. 15, 2010

Restricted stock

Restricted stock

Restricted stock

Restricted stock

SARs

SARs

SARs

SARs

Stock options

Stock options

Stock options

Stock options

Non employee director deferred compensation

Non employee director deferred compensation

Non employee director deferred compensation

Non employee director deferred compensation

Convertible senior note

Convertible senior note

Convertible senior note

Convertible senior note

3.25% Convertible Senior Notes due 2016

Reconciliation of Weighted-Average Diluted Shares Outstanding

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted average common shares outstanding - basic

33,413,000

30,214,000

31,350,000

26,819,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted Average Number of Shares Outstanding - Diluted

33,413,000

30,214,000

31,350,000

26,819,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Anti-dilutive Effect

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount

1,570,000

906,000

1,320,000

813,000

805,000

777,000

857,000

688,000

83,000

119,000

65,000

115,000

7,000

7,000

7,000

7,000

4,000

3,000

4,000

3,000

671,000

0

387,000

0

'

Convertible Senior Note Due 2016

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.25% Convertible Note, Shares To Be Received Upon Conversion

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,700,000

3.25% Convertible Note, Conversion Price

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$42.40

Divestitures_and_Discontinued_1

Divestitures and Discontinued Operations Additional Information (Details) (USD $)	9 Months Ended
	Sep. 30, 2013
Piceance and NECO Asset Group	'
Additional Disclosures	'
Proceeds from Sale of Oil and Gas Property and Equipment ($ in millions)	$177,600,000
Proceeds To Non-Affiliated Investor Partners ($ in millions)	17,000,000
Pre-tax loss on sale of crude oil and gas properties ($ in millions)	-2,300,000
Permian Basin Asset Group	'
Additional Disclosures	'
Oil and gas assets sale price before adjustments ($ in millions)	173,900,000
Proceeds from Sale of Oil and Gas Property and Equipment ($ in millions)	$189,200,000
Shallow Upper Devonian Assets	'
Additional Disclosures	'
Appalachian Basin Wells Held for Sale (Number of wells)	3,500

Discontinued_Operations_and_Di

Discontinued Operations and Disposal Groups (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
Balance Sheet - Discontinued Operations	'		'	'		'
Asset retirement obligation	$22,788	[1]	'	$22,788	[1]	'
Statement of Operations - Discontinued Operations	'		'	'		'
Income (loss) from discontinued operations, net of tax	-782		-4,632	4,171		-2,468
Net Assets Held for Sale	'		'	'		'
Balance Sheet - Discontinued Operations	'		'	'		'
Properties and equipment	130,835		'	130,835		'
Accumulated depreciation, depletion and amortization	-101,801		'	-101,801		'
Total assets	29,034		'	29,034		'
Asset retirement obligation	-22,788		'	-22,788		'
Net assets	6,246		'	6,246		'
Piceance and NECO Asset Group	'		'	'		'
Statement of Operations - Discontinued Operations	'		'	'		'
Gain on sale of properties and equipment	'		'	2,300		'
Segment, Discontinued Operations	'		'	'		'
Statement of Operations - Discontinued Operations	'		'	'		'
Crude oil, natural gas and NGL sales	-58		7,624	20,398		25,972
Sales from natural gas marketing	1,789		392	2,825		1,149
Well operations, pipeline income and other	31		446	890		1,476
Total revenues	1,762		8,462	24,113		28,597
Production Costs	18		4,959	7,975		17,743
Cost of natural gas marketing	1,679		338	2,673		1,010
Depreciation, depletion and amortization	0		10,362	2,258		32,873
Other	77		298	2,531		949
Gain on sale of properties and equipment	1,254		0	2,330		-19,920
Total costs, expenses and other	3,028		15,957	17,767		32,655
Income (loss) from discontinued operations	-1,266		-7,495	6,346		-4,058
Provision for income taxes	484		2,863	-2,175		1,590
Income (loss) from discontinued operations, net of tax	($782)		($4,632)	$4,171		($2,468)
[1]	Represents asset retirement obligations related to our assets held for sale. See Note 12, Assets Held for Sale, Divestitures and Discontinued Operations and Note 15, Subsequent Events, for additional information regarding the potential sale of these properties.

Transactions_with_Affiliates_a2

Transactions with Affiliates and Other Related Parties (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Related Party Transactions:	'	'	'	'
Production costs	$19,057,000	$15,797,000	$51,091,000	$41,106,000
Exploration expense	2,030,000	1,773,000	5,156,000	6,019,000
General and administrative expense	16,080,000	13,710,000	46,978,000	42,796,000
PDCM	'	'	'	'
Related Party Transactions:	'	'	'	'
Sales from natural gas marketing	4,774,000	2,894,000	12,742,000	7,459,000
Cost of natural gas marketing	4,680,000	2,838,000	12,492,000	7,313,000
Well operating and administrative services billed to PDCM	3,600,000	3,000,000	10,400,000	9,200,000
Affiliated Partnerships	'	'	'	'
Related Party Transactions:	'	'	'	'
Sales from natural gas marketing	348,000	145,000	931,000	368,000
Cost of natural gas marketing	341,000	142,000	913,000	360,000
PDCE proportionate share	'	'	'	'
Related Party Transactions:	'	'	'	'
Production costs	1,068,000	1,022,000	3,121,000	3,080,000
Exploration expense	127,000	110,000	366,000	357,000
General and administrative expense	$584,000	$370,000	$1,716,000	$1,168,000

Business_segments_Details

Business segments (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	Dec. 31, 2012
Segment Reporting Information:	'	'	'	'	'
Revenues	$77,116	$32,720	$270,247	$223,466	'
Segment income (loss) before income taxes	-25,373	-43,279	-62,527	-3,004	'
Segment assets	2,010,963	'	2,010,963	'	1,826,848
Oil and gas exploration and production segment	'	'	'	'	'
Segment Reporting Information:	'	'	'	'	'
Revenues	60,170	21,542	221,552	192,294	'
Segment income (loss) before income taxes	4,573	-16,266	27,243	76,852	'
Segment assets	1,874,679	'	1,874,679	'	1,723,011
Gas marketing segment	'	'	'	'	'
Segment Reporting Information:	'	'	'	'	'
Revenues	16,946	11,178	48,695	31,172	'
Segment income (loss) before income taxes	-181	-82	-233	331	'
Segment assets	35,532	'	35,532	'	11,090
Corporate and other segment	'	'	'	'	'
Segment Reporting Information:	'	'	'	'	'
Segment income (loss) before income taxes	-29,765	-26,931	-89,537	-80,187	'
Segment assets	71,718	'	71,718	'	92,747
Assets held for sale	'	'	'	'	'
Segment Reporting Information:	'	'	'	'	'
Segment assets	$29,034	'	$29,034	'	$0

Subsequent_Event_Subsequent_Ev1

Subsequent Event Subsequent Event (Details) (USD $)	0 Months Ended
In Millions, unless otherwise specified	Oct. 08, 2013	Oct. 08, 2013	Oct. 08, 2013	Sep. 30, 2013
		Shallow Upper Devonian Sale	PDCE proportionate share	Shallow Upper Devonian Letter of Credit
			Shallow Upper Devonian Sale
Subsequent Event:	'	'	'	'
Purchase and Sale Agreement Execution Date	8-Oct-13	'	'	'
Oil and gas assets sale price before adjustments ($ in millions)	'	$18.80	$6.20	'
PDC Irrevocable Standby Letter of Credit ($)	'	'	'	$6.70