Athlon 10-Q 21 Aug 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014	Aug. 20, 2014
Document and Entity Information	'	'
Entity Registrant Name	'Athlon Holdings LP	'
Entity Central Index Key	'0001574672	'
Document Type	'10-Q	'
Document Period End Date	30-Jun-14	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Current Reporting Status	'No	'
Entity Filer Category	'Non-accelerated Filer	'
Entity Units Outstanding	'	98,790,902
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$242,895	$113,025
Accounts receivable	81,463	48,238
Inventory	1,176	928
Deferred taxes	139	10
Other	354	487
Total current assets	326,027	162,688
Properties and equipment, at cost - full cost method:	'	'
Evaluated, including wells and related equipment	2,070,655	1,244,178
Unevaluated	555,905	89,859
Accumulated depletion, depreciation, and amortization	-227,195	-160,779
Oil and natural gas properties and equipment, net	2,399,365	1,173,258
Derivatives, at fair value	318	2,330
Debt issuance costs	25,908	14,679
Other	2,097	1,447
Total assets	2,753,715	1,354,402
Accounts payable:	'	'
Trade	9,861	459
Intercompany	1,644	1,240
Accrued liabilities:	'	'
Lease operating	9,208	6,563
Production, severance, and ad valorem taxes	6,949	2,550
Development capital	120,523	68,059
Interest	14,293	7,790
Derivatives, at fair value	33,542	8,354
Revenue payable	32,827	20,513
Other	9,555	2,795
Total current liabilities	238,402	118,323
Asset retirement obligations, net of current portion	10,496	6,795
Long-term debt	1,150,000	500,000
Deferred taxes	4,815	3,936
Derivatives, at fair value	3,320	'
Other	140	101
Total liabilities	1,407,173	629,155
Commitments and contingencies	'	'
Partners' equity	1,346,542	725,247
Total liabilities and partners' equity	$2,753,715	$1,354,402

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues:	'	'	'	'
Oil	$114,137	$54,609	$201,219	$100,268
Natural gas	8,687	4,363	16,112	7,730
Natural gas liquids	13,686	6,193	24,848	11,913
Total revenues	136,510	65,165	242,179	119,911
Production:	'	'	'	'
Lease operating	14,713	7,775	25,449	15,012
Production, severance, and ad valorem taxes	8,661	4,312	15,413	8,051
Depletion, depreciation, and amortization	38,470	20,358	66,546	38,411
General and administrative	13,430	3,558	20,858	6,840
Acquisition costs	1,207	94	1,825	151
Derivative fair value loss (gain)	32,397	-12,555	43,577	-5,706
Accretion of discount on asset retirement obligations	222	162	417	311
Total expenses	109,100	23,704	174,085	63,070
Operating income	27,410	41,461	68,094	56,841
Other income (expenses):	'	'	'	'
Interest	-13,528	-12,082	-22,706	-16,556
Other	23	'	26	'
Total other expenses	-13,505	-12,082	-22,680	-16,556
Income before income taxes	13,905	29,379	45,414	40,285
Income tax provision	409	391	749	418
Net income	$13,496	$28,988	$44,665	$39,867
Net income per unit:	'	'	'	'
Basic (in dollars per unit)	$0.14	$0.43	$0.49	$0.58
Diluted (in dollars per unit)	$0.14	$0.43	$0.49	$0.58
Weighted average units outstanding:	'	'	'	'
Basic (in units)	95,212	68,196	89,629	68,196
Diluted (in units)	95,212	68,196	89,629	68,196

CONSOLIDATED_STATEMENT_OF_CHAN

CONSOLIDATED STATEMENT OF CHANGES IN PARTNERS' EQUITY (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Increase (Decrease) in Partners' Equity	'
Balance at December 31, 2013	$725,247
Equity-based compensation	9,024
Net contributions from Athlon Energy Inc.	567,606
Net income	44,665
Balance at June 30, 2014	$1,346,542

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:	'	'
Net income	$44,665	$39,867
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depletion, depreciation, and amortization	66,546	38,411
Deferred taxes	749	418
Non-cash derivative loss (gain)	30,519	-6,127
Equity-based compensation	8,267	113
Other	1,955	3,979
Changes in operating assets and liabilities, net of effects from acquisitions:	'	'
Accounts receivable	-32,101	-12,623
Other current assets	1,907	424
Accounts payable	2,825	-2,503
Intercompany payable	404	'
Accrued interest	6,503	6,898
Revenue payable	12,314	5,723
Other current liabilities	11,862	4,651
Other assets	-90	'
Net cash provided by operating activities	156,325	79,231
Cash flows from investing activities:	'	'
Acquisitions of oil and natural gas properties	-974,732	-16,482
Development of oil and natural gas properties	-256,057	-161,514
Other	-830	-336
Net cash used in investing activities	-1,231,619	-178,332
Cash flows from financing activities:	'	'
Proceeds from long-term debt, net of issuance costs	797,493	594,647
Payments on long-term debt	-160,000	-427,426
Net contributions from (distributions to) Athlon Energy Inc.	567,671	-7
Distributions to Class A limited partners	'	-75,000
Other	'	563
Net cash provided by financing activities	1,205,164	92,777
Increase (decrease) in cash and cash equivalents	129,870	-6,324
Cash and cash equivalents, beginning of period	113,025	8,871
Cash and cash equivalents, end of period	$242,895	$2,547

Formation_of_the_Partnership_a

Formation of the Partnership and Description of Business	6 Months Ended
	Jun. 30, 2014
Formation of the Partnership and Description of Business	'
Formation of the Partnership and Description of Business	'
	Note 1.         Formation of the Partnership and Description of Business
	Athlon Holdings LP (together with its subsidiaries, “Holdings”), a Delaware limited partnership, is an independent exploration and production company focused on the acquisition, development, and exploitation of unconventional oil and liquids-rich natural gas reserves in the Permian Basin.  Athlon Finance Corp., a Delaware corporation, is a wholly owned subsidiary of Holdings whose sole purpose is to serve as the co-issuer of Holdings' senior notes.  Athlon Holdings GP LLC serves as Holdings’ general partner with no obligations to make capital contributions and no rights to distributions.
	On April 26, 2013, Holdings underwent a corporate reorganization and as a result, Holdings became a majority-owned subsidiary of Athlon Energy Inc. (together with its subsidiaries, “Athlon”), a Delaware corporation.  Prior to the corporate reorganization, Holdings was a party to a limited partnership agreement with its management team and certain employees and Apollo Athlon Holdings, L.P. (“Apollo”), which is an affiliate of Apollo Global Management, LLC.  Prior to the corporate reorganization, Apollo Investment Fund VII, L.P. and its parallel funds (the “Apollo Funds”) and Holdings’ management team and certain employees owned all of Holdings’ Class A limited partner interests and Holdings’ management team and certain employees owned all of Holdings’ Class B limited partner interests.
	In the corporate reorganization, the Apollo Funds entered into a number of distribution and contribution transactions pursuant to which the Apollo Funds exchanged their Holdings’ Class A limited partner interests for shares of Athlon’s common stock.  The remaining holders of Holdings’ Class A limited partner interests did not exchange their interests in the reorganization transactions.  In addition, the holders of Holdings’ Class B limited partner interests exchanged their interests for shares of Athlon’s common stock subject to the same conditions and vesting terms.
	Initial Public Offering
	On August 7, 2013, Athlon completed its initial public offering (the “Athlon IPO”) of 15,789,474 shares of its common stock at $20.00 per share and received net proceeds of approximately $295.7 million, after deducting underwriting discounts and commissions and offering expenses.  Upon closing of the Athlon IPO, Holdings’ limited partnership agreement was amended and restated to, among other things, modify Holdings’ capital structure by replacing its different classes of interests with a single new class of units, the “New Holdings Units”.  Holdings’ management team and certain employees that held Class A limited partner interests now own 1,855,563 New Holdings Units and entered into an exchange agreement under which (subject to the terms of the exchange agreement) they have the right to exchange their New Holdings Units for shares of Athlon’s common stock on a one-for-one basis, subject to customary conversion rate adjustments for stock splits, stock dividends, and reclassifications.  Please read “Note 12. Related Party Transactions” for additional discussion.  All other New Holdings Units are held by Athlon.

Basis_of_Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2014
Basis of Presentation	'
Basis of Presentation	'
	Note 2.         Basis of Presentation
	Holdings’ consolidated financial statements include the accounts of its wholly owned subsidiaries.  All material intercompany balances and transactions have been eliminated in consolidation.
	In the opinion of management, the accompanying unaudited consolidated financial statements include all adjustments necessary to present fairly, in all material respects, Holdings’ financial position as of June 30, 2014, results of operations for the three and six months ended June 30, 2014 and 2013, and cash flows for the six months ended June 30, 2014 and 2013.  All adjustments are of a normal recurring nature.  These interim results are not necessarily indicative of results for an entire year.
	Certain amounts and disclosures have been condensed and omitted from the unaudited consolidated financial statements pursuant to the rules and regulations of the United States Securities and Exchange Commission (the “SEC”).  Therefore, these unaudited consolidated financial statements should be read in conjunction with Holdings’ audited consolidated financial statements and related notes thereto included in Holdings’ final prospectus filed with the SEC pursuant to Rule 424(b)(3) of the Securities Act of 1933, as amended, on July 24, 2014.
	New Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers”.  ASU 2014-09 supersedes most of the existing revenue recognition requirements in accounting principles generally accepted in the United States (“GAAP”) and requires (i) an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration the entity expects to be entitled to in exchange for those goods or services and (ii) requires expanded disclosures regarding the nature, amount, timing, and certainty of revenue and cash flows from contracts with customers.  ASU 2014-09 is effective retrospectively for annual and interim reporting periods beginning after December 15, 2016, with early application not permitted.  Holdings is evaluating the impact, if any, that the adoption of ASU 2014-09 will have on its financial position, results of operations, and liquidity.
	No other new accounting pronouncements issued or effective from January 1, 2014 through the date of this Report, had or are expected to have a material impact on Holdings’ unaudited consolidated financial statements.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2014
Acquisitions	'
Acquisitions	'
	Note 3.         Acquisitions
	On June 2, 2014 and June 3, 2014, Holdings acquired certain oil and natural gas properties and related assets in the Permian Basin in West Texas from Hibernia Holdings, LLC (“Hibernia”) and Piedra Energy II, LLC (“Piedra”), respectively, for approximately $388.7 million and $290.2 million in cash, respectively (the “Acquisitions”).  The Acquisitions were financed with a portion of the net proceeds from debt and equity offerings.  Please read “Note 7. Long-Term Debt” and “Note 8. Partners’ Equity” for additional discussion of these offerings.  The operations of these properties have been included in the accompanying Consolidated Statements of Operations with those of Holdings from the date of acquisition.  Holdings incurred approximately $1.2 million of transaction costs related to the Acquisitions, which are included in “Acquisition costs” in the accompanying Consolidated Statements of Operations.
	Based on currently available information, the estimated allocation of the purchase price to the fair value of the assets acquired and liabilities assumed from the Acquisitions was as follows as of June 30, 2014:
		Hibernia		Piedra		Total
		(in thousands)
	Evaluated, including wells and related equipment	$	240,745	$	173,041	$	413,786
	Unevaluated	148,246		117,242		265,488
	Inventory	499		759		1,258
	Total assets acquired	389,490		291,042		680,532
	Other current liabilities	107		289		396
	Asset retirement obligations	706		536		1,242
	Total liabilities assumed	813		825		1,638
	Fair value of net assets acquired	$	388,677	$	290,217	$	678,894
	At June 30, 2014, Holdings was awaiting final close on the Acquisitions, which will contain certain customary purchase price adjustments.
	The following unaudited pro forma condensed financial data was derived from the historical financial statements of Holdings and from the accounting records of Hibernia and Piedra to give effect to the Acquisitions as if they had occurred on January 1, 2013.  The unaudited pro forma condensed financial information has been included for comparative purposes only and is not necessarily indicative of the results that might have occurred had the Acquisitions taken place on January 1, 2013 and is not intended to be a projection of future results.
		Three months ended June 30,				Six months ended June 30,
		2014		2013		2014		2013
		(in thousands, except per unit amounts)
	Pro forma total revenues	$	150,961	$	74,336	$	277,617	$	138,670
	Pro forma net income	$	16,880	$	22,473	$	47,308	$	27,661
	Pro forma net income per unit:
	Basic	$	0.17	$	0.27	$	0.47	$	0.33
	Diluted	$	0.17	$	0.27	$	0.47	$	0.33

Evaluated_Properties

Evaluated Properties	6 Months Ended
	Jun. 30, 2014
Evaluated Properties	'
Evaluated Properties	'
	Note 4. Evaluated Properties
	Amounts shown in the accompanying Consolidated Balance Sheets as “Evaluated, including wells and related equipment” consisted of the following as of the dates indicated:
		June 30,		December 31,
		2014		2013
		(in thousands)
	Evaluated leasehold costs	$	912,321	$	448,689
	Wells and related equipment - completed	1,111,196		748,900
	Wells and related equipment - in process	47,138		46,589
	Total evaluated	$	2,070,655	$	1,244,178

Fair_Value_Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2014
Fair Value Measurements	'
Fair Value Measurements	'
	Note 5.  Fair Value Measurements
	The book values of cash and cash equivalents, accounts receivable, and accounts payable approximate fair value due to the short-term nature of these instruments.  Commodity derivative contracts are marked-to-market each quarter and are thus stated at fair value in the accompanying Consolidated Balance Sheets.  As of June 30, 2014, the fair value of Holdings’ 73/8% senior notes due 2021 was approximately $547.5 million and the fair value of Holdings’ 6% senior notes due 2022 was approximately $674.4 million using open market quotes (“Level 1” input).
	Derivative Policy
	Holdings uses various financial instruments for non-trading purposes to manage and reduce price volatility and other market risks associated with its oil production.  These arrangements are structured to reduce Holdings’ exposure to commodity price decreases, but they can also limit the benefit Holdings might otherwise receive from commodity price increases.  Holdings’ risk management activity is generally accomplished through over-the-counter commodity derivative contracts with large financial institutions, most of which are lenders under Holdings’ credit agreement.
	Holdings applies the provisions of the “Derivatives and Hedging” topic of the Accounting Standards Codification, which requires each derivative instrument to be recorded in the accompanying Consolidated Balance Sheets at fair value.  If a derivative has not been designated as a hedge or does not otherwise qualify for hedge accounting, it must be adjusted to fair value through earnings.  Holdings elected not to designate its current portfolio of commodity derivative contracts as hedges for accounting purposes.  Therefore, changes in fair value of these derivative instruments are recognized in earnings and included in “Derivative fair value loss (gain)” in the accompanying Consolidated Statements of Operations.
	Holdings enters into commodity derivative contracts for the purpose of economically fixing the price of its anticipated oil production even though Holdings does not designate the derivatives as hedges for accounting purposes.  Holdings classifies cash flows related to derivative contracts based on the nature and purpose of the derivative.  As the derivative cash flows are considered an integral part of Holdings’ oil and natural gas operations, they are classified as cash flows from operating activities in the accompanying Consolidated Statements of Cash Flows.
	Commodity Derivative Contracts
	Commodity prices are often subject to significant volatility due to many factors that are beyond Holdings’ control, including but not limited to: prevailing economic conditions, supply and demand of hydrocarbons in the marketplace, actions by speculators, and geopolitical events such as wars or natural disasters.  Holdings manages oil price risk with swaps, which provide a fixed price for a notional amount of sales volumes.  The following table summarizes Holdings’ open commodity derivative contracts as of June 30, 2014:
	Period	Average		Weighted-			Net Liability Fair
		Daily		Average			Market Value
		Swap		Swap Price
		Volume
		(Bbl)		(per Bbl)			(in thousands)
	Q3 2014	9,950		$	92.52
	Q4 2014	10,961		92.31
	Q3-Q4 2014	10,455		92.41			$	(20,320	)
	Q1 2015	9,800		90.9
	Q2 2015	9,800		90.9
	Q3 2015	4,300		91.11
	Q4 2015	4,300		91.11
	2015	7,027		90.97			(16,224		)
							$	(36,544	)
	Counterparty Risk.  At June 30, 2014, Holdings did not have a net asset position with any of its counterparties.
	Holdings does not require collateral from its counterparties for entering into derivative instruments, so in order to mitigate the credit risk associated with such derivative instruments, Holdings enters into an International Swap Dealers Association Master Agreement (“ISDA Agreement”) with each of its counterparties.  The ISDA Agreement is a standardized, bilateral contract between a given counterparty and Holdings.  Instead of treating each derivative transaction between the counterparty and Holdings separately, the termination provision of the ISDA Agreement enables the counterparty and Holdings to aggregate all trades under such agreement and treat them as a single agreement.  This arrangement is intended to benefit Holdings in two ways: (i) default by a counterparty under a single trade can trigger rights to terminate all trades with such counterparty that are subject to the ISDA Agreement; and (ii) netting of settlement amounts reduces Holdings’ credit exposure to a given counterparty in the event of close-out.  Holdings’ accounting policy is to not offset fair value amounts between different counterparties for derivative instruments in the accompanying Consolidated Balance Sheets.
	Tabular Disclosures of Fair Value Measurements
	The following table summarizes the fair value of Holdings’ derivative instruments not designated as hedging instruments as of the dates indicated:
		Oil			Commodity			Total
	Balance Sheet	Commodity			Derivatives			Commodity
	Location	Derivatives			Netting (a)			Derivatives
		(in thousands)
	As of June 30, 2014
	Assets
	Derivatives - current	$	112		$	(112	)	$	—
	Derivatives - noncurrent	318			—			318
	Total assets	430			(112		)	318
	Liabilities
	Derivatives - current	(33,654		)	112			(33,542		)
	Derivatives - noncurrent	(3,320		)	—			(3,320		)
	Total liabilities	(36,974		)	112			(36,862		)
	Net liabilities	$	(36,544	)	$	—		$	(36,544	)
	As of December 31, 2013
	Assets
	Derivatives - current	$	143		$	(143	)	$	—
	Derivatives - noncurrent	2,330			—			2,330
	Total assets	2,473			(143		)	2,330
	Liabilities
	Derivatives - current	(8,497		)	143			(8,354		)
	Derivatives - noncurrent	—			—			—
	Total liabilities	(8,497		)	143			(8,354		)
	Net liabilities	$	(6,024	)	$	—		$	(6,024	)
	(a)     Represents counterparty netting under ISDA Agreements, which allow for netting of commodity derivative contracts.  These derivative instruments are reflected net on the accompanying Consolidated Balance Sheets.
	The following table summarizes the effect of derivative instruments not designated as hedges on the accompanying Consolidated Statements of Operations for the periods indicated:
				Amount of Loss (Gain) Recognized in Income
		Location of Loss (Gain)		Three months ended June 30,						Six months ended June 30,
	Derivatives Not Designated as Hedges	Recognized in Income		2014			2013			2014			2013
				(in thousands)
	Commodity derivative contracts	Derivative fair value loss (gain)		$	32,397		$	(12,555	)	$	43,577		$	(5,706	)
	Fair Value Hierarchy
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.  GAAP establishes a three-tier fair value hierarchy, which prioritizes the inputs used to measure fair value.  The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements).  The three levels of the fair value hierarchy are defined as follows:
	·         Level 1 — Inputs such as unadjusted, quoted prices that are available in active markets for identical assets or liabilities.
	·         Level 2 — Inputs, other than quoted prices within Level 1, that are either directly or indirectly observable, such as quoted prices for similar assets and liabilities or quoted prices in inactive markets.
	·         Level 3 — Inputs that are unobservable for use when little or no market data exists requiring the use of valuation methodologies that result in management’s best estimate of fair value.
	As required by GAAP, Holdings utilizes the most observable inputs available for the valuation technique used.  The financial assets and liabilities are classified in their entirety based on the lowest level of input that is of significance to the fair value measurement.  Holdings’ assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of the financial assets and liabilities and their placement within the fair value hierarchy levels.  The following methods and assumptions were used to estimate the fair values of Holdings’ assets and liabilities that are accounted for at fair value on a recurring basis:
·         Level 2 — Fair values of swaps are estimated using a combined income-based and market-based valuation methodology based upon forward commodity price curves obtained from independent pricing services.  Settlement is determined by the average underlying price over a predetermined period of time.  Holdings uses observable inputs in an option pricing valuation model to determine fair value such as: (i) current market and contractual prices for the underlying instruments; (ii) quoted forward prices for oil; (iii) interest rates, such as a LIBOR curve for a term similar to the commodity derivative contract; and (iv) appropriate volatilities.
Holdings adjusts the valuations from the valuation model for nonperformance risk.  For commodity derivative contracts which are in an asset position, Holdings adds the counterparty’s credit default swap spread to the risk-free rate.  If a counterparty does not have a credit default swap spread, Holdings uses other companies with similar credit ratings to determine the applicable spread.  For commodity derivative contracts which are in a liability position, Holdings uses the yield on its senior notes less the risk-free rate.  All fair values have been adjusted for nonperformance risk resulting in a decrease in the net commodity derivative liability of approximately $630,000 and $39,000 as of June 30, 2014 and December 31, 2013, respectively.
The following table sets forth Holdings’ assets and liabilities that were accounted for at fair value on a recurring basis as of the dates indicated:
				Fair Value Measurements at Reporting Date Using
				Quoted Prices in
				Active Markets for			Significant Other			Significant
				Identical Assets			Observable Inputs			Unobservable Inputs
Description	Net Liability			(Level 1)			(Level 2)			(Level 3)
	(in thousands)
As of June 30, 2014
Oil derivative contracts - swaps	$	(36,544	)	$	—		$	(36,544	)	$	—
As of December 31, 2013
Oil derivative contracts - swaps	$	(6,024	)	$	—		$	(6,024	)	$	—

Asset_Retirement_Obligations

Asset Retirement Obligations	6 Months Ended
	Jun. 30, 2014
Asset Retirement Obligations	'
Asset Retirement Obligations	'
	Note 6. Asset Retirement Obligations
	Asset retirement obligations relate to future plugging and abandonment expenses on oil and natural gas properties and related facilities disposal.  The following table summarizes the changes in Holdings’ asset retirement obligations for the six months ended June 30, 2014 (in thousands):
	Balance at January 1	$	6,855
	Liabilities assumed in acquisitions	2,177
	Liabilities incurred from new wells	867
	Liabilities settled	(103		)
	Accretion of discount	417
	Revisions of previous estimates	292
	Balance at June 30	10,505
	Less: current portion	9
	Asset retirement obligations - long term	$	10,496

LongTerm_Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2014
Long-Term Debt	'
Long-Term Debt	'
	Note 7. Long-Term Debt
	Long-term debt consisted of the following as of the dates indicated:
		Maturity		June 30,			December 31,
		Date		2014			2013
				(in thousands)
	Credit agreement	3/19/18		$	—		$	—
	73/8% senior notes	4/15/21		500,000			500,000
	6% senior notes	5/1/22		650,000			—
	Total			$	1,150,000		$	500,000
	Senior Notes
	In April 2013, Holdings issued $500 million aggregate principal amount of 73/8% senior unsecured notes due 2021 (the “2021 Notes”).  Athlon is an unconditional guarantor of the 2021 Notes.  Under the indenture, starting on April 15, 2016, Holdings will be able to redeem some or all of the 2021 Notes at a premium that will decrease over time, plus accrued and unpaid interest to the date of redemption.  Prior to April 15, 2016, Holdings will be able, at its option, to redeem up to 35% of the aggregate principal amount of the 2021 Notes at a price of 107.375% of the principal thereof, plus accrued and unpaid interest to the date of redemption, with an amount equal to the net proceeds from certain equity offerings.  In addition, at Holdings’ option, prior to April 15, 2016, Holdings may redeem some or all of the 2021 Notes at a redemption price equal to 100% of the principal amount of the 2021 Notes, plus an “applicable premium”, plus accrued and unpaid interest to the date of redemption.  Certain asset dispositions or a change in control will be triggering events that may require Holdings to repurchase all or any part of a noteholder’s 2021 Notes at a purchase price in cash equal to 101% of the principal amount thereof, plus accrued and unpaid interest, if any, to but excluding the date of repurchase.  Interest on the 2021 Notes is payable in cash semi-annually in arrears, commencing on October 15, 2013, through maturity.
	On May 1, 2014, Holdings completed a private placement of $650 million aggregate principal amount of 6% senior unsecured notes due 2022 (the “2022 Notes”) and received net proceeds of approximately $639.1 million, after deducting initial purchasers’ discounts and debt issuance costs, which were used to fund a portion of the purchase price of the Acquisitions, to provide additional liquidity for use in Holdings’ drilling program, and for general partnership purposes.  Athlon is an unconditional guarantor of the 2022 Notes.  Under the indenture, starting on May 1, 2017, Holdings will be able to redeem some or all of the 2022 Notes at a premium that will decrease over time, plus accrued and unpaid interest to the date of redemption.  Prior to May 1, 2017, Holdings will be able, at its option, to redeem up to 35% of the aggregate principal amount of the 2022 Notes at a price of 106% of the principal thereof, plus accrued and unpaid interest to the date of redemption, with an amount equal to the net proceeds from certain equity offerings.  In addition, at Holdings’ option, prior to May 1, 2017, Holdings may redeem some or all of the 2022 Notes at a redemption price equal to 100% of the principal amount of the 2022 Notes, plus an “applicable premium”, plus accrued and unpaid interest to the date of redemption.  If a change of control occurs on or prior to July 15, 2015, Holdings may redeem all, but not less than all, of the 2022 Notes at 110% of the principal amount thereof plus accrued and unpaid interest to, but not including, the redemption date.  Certain asset dispositions or a change of control that occurs after July 15, 2015 will be triggering events that may require Holdings to repurchase all or any part of a noteholder’s 2022 Notes at a purchase price in cash equal to 101% of the principal amount thereof, plus accrued and unpaid interest, if any, up to but excluding the date of repurchase.  Interest on the 2022 Notes is payable in cash semi-annually in arrears, commencing on November 1, 2014, through maturity.
	The indentures governing Holdings’ senior notes contain covenants, including, among other things, covenants that restrict Holdings’ ability to:
	·       make distributions, investments, or other restricted payments if Holdings’ fixed charge coverage ratio is less than 2.0 to 1.0;
	·       incur additional indebtedness if Holdings’ fixed charge coverage ratio would be less than 2.0 to 1.0; and
	·       create liens, sell assets, consolidate or merge with any other person, or engage in transactions with affiliates.
	These covenants are subject to a number of important qualifications, limitations, and exceptions.  In addition, the indenture contains other customary terms, including certain events of default upon the occurrence of which Holdings’ senior notes may be declared immediately due and payable.
	As of June 30, 2014, Holdings was in compliance with all covenants of its senior notes.
	Credit Agreement
	Holdings is a party to an amended and restated credit agreement dated March 19, 2013 (the “Credit Agreement”), which matures on March 19, 2018.  The Credit Agreement provides for revolving credit loans to be made to Holdings from time to time and letters of credit to be issued from time to time for the account of Holdings or any of its restricted subsidiaries.  The aggregate amount of the commitments of the lenders under the Credit Agreement is $1.0 billion.  Availability under the Credit Agreement is subject to a borrowing base, which is redetermined semi-annually and upon requested special redeterminations.  As of June 30, 2014, the borrowing base was $837.5 million and there were no outstanding borrowings and no outstanding letters of credit under the Credit Agreement.
	Obligations under the Credit Agreement are secured by a first-priority security interest in substantially all of Holdings’ proved reserves.  In addition, obligations under the Credit Agreement are guaranteed by Athlon.
	Loans under the Credit Agreement are subject to varying rates of interest based on (i) outstanding borrowings in relation to the borrowing base and (ii) whether the loan is a Eurodollar loan or a base rate loan.  Eurodollar loans under the Credit Agreement bear interest at the Eurodollar rate plus the applicable margin indicated in the following table, and base rate loans under the Credit Agreement bear interest at the base rate plus the applicable margin indicated in the following table.  Holdings also incurs a quarterly commitment fee on the unused portion of the Credit Agreement indicated in the following table:
	Ratio of Outstanding Borrowings to Borrowing Base	Unused		Applicable		Applicable
		Commitment Fee		Margin for		Margin for Base
				Eurodollar Loans		Rate Loans
	Less than or equal to .30 to 1	0.375	%	1.5	%	0.5	%
	Greater than .30 to 1 but less than or equal to .60 to 1	0.375	%	1.75	%	0.75	%
	Greater than .60 to 1 but less than or equal to .80 to 1	0.5	%	2	%	1	%
	Greater than .80 to 1 but less than or equal to .90 to 1	0.5	%	2.25	%	1.25	%
	Greater than .90 to 1	0.5	%	2.5	%	1.5	%
	The “Eurodollar rate” for any interest period (either one, two, three, or six months, as selected by Holdings) is the rate equal to the British Bankers Association London Interbank Offered Rate (“LIBOR”) for deposits in dollars for a similar interest period.  The “Base Rate” is calculated as the highest of: (i) the annual rate of interest announced by Bank of America, N.A. as its “prime rate”; (ii) the federal funds effective rate plus 0.5%; or (iii) except during a “LIBOR Unavailability Period”, the Eurodollar rate (for dollar deposits for a one-month term) for such day plus 1.0%.
	Any outstanding letters of credit reduce the availability under the Credit Agreement.  Borrowings under the Credit Agreement may be repaid from time to time without penalty.
	The Credit Agreement contains covenants including, among others, the following:
	·         a prohibition against incurring additional debt, subject to permitted exceptions;
	·         a restriction on creating liens on Holdings’ assets and the assets of its operating subsidiaries, subject to permitted exceptions;
	·         restrictions on merging and selling assets outside the ordinary course of business;
	·         restrictions on use of proceeds, investments, transactions with affiliates, or change of principal business;
	·         a requirement that Holdings maintain a ratio of consolidated total debt to EBITDAX (as defined in the Credit Agreement) of not more than 4.5 to 1.0; and
	·         a provision limiting commodity derivative contracts to a volume not exceeding 85% of projected production from proved reserves for a period not exceeding 66 months from the date the commodity derivative contract is entered into.
	As of June 30, 2014, Holdings was in compliance with all covenants of the Credit Agreement.
	The Credit Agreement contains customary events of default, including our failure to comply with the financial ratios described above, which would permit the lenders to accelerate the debt if not cured within applicable grace periods.  If an event of default occurs and is continuing, lenders with a majority of the aggregate commitments may require Bank of America, N.A. to declare all amounts outstanding under the Credit Agreement to be immediately due and payable.

Partners_Equity

Partners' Equity	6 Months Ended
	Jun. 30, 2014
Partners' Equity	'
Partners' Equity	'
	Note 8. Partners’ Equity
	On April 23, 2014, Athlon completed a public offering of 14,806,250 shares of its common stock at $40.00 per share and received net proceeds of approximately $570.8 million, after deducting underwriting discounts and commissions and offering expenses, which were used to fund a portion of the purchase price of the Acquisitions, to reduce outstanding indebtedness under the Credit Agreement, to provide additional liquidity for use in Holdings’ drilling program, and for general partnership purposes.  Upon consummation of the offering, Athlon’s ownership percentage of Holdings increased.
	The following table shows Holdings’ partnership interests as of June 30, 2014:
			Partnership
			Interest
	Athlon Holdings GP LLC	General Partner	0	%
	Athlon Energy Inc.	Limited Partner	98.1	%
	Management team and certain employees	Limited Partner	1.9	%

Earnings_Per_Unit

Earnings Per Unit	6 Months Ended
	Jun. 30, 2014
Earnings Per Unit	'
Earnings Per Unit	'
	Note 9. Earnings Per Unit
	Prior to the consummation of the Athlon IPO, Holdings had 989,508 outstanding limited partner units.  In conjunction with the closing of the Athlon IPO, certain of Holdings’ Class A and Class B limited partners were subject to an adjustment based on the Athlon IPO price of $20.00 per share and an actual 65.266-for-1 stock split.  Following this adjustment and stock split, the number of outstanding limited partner units increased from 989,508 units to 68,195,178 units.  The one-to-one conversion of Holdings’ interests in April 2013 to 989,508 limited partner units is akin to a stock split and has been treated as such in Holdings’ earnings per unit (“EPU”) calculations.  Accordingly, Holdings assumes that 68,195,178 limited partner units were outstanding during periods prior to the Athlon IPO for purposes of calculating EPU.
	Holdings’ Amended and Restated Agreement of Limited Partnership provides that at any time Athlon issues a share of common stock, other than pursuant to an incentive plan or an exchange transaction, the net proceeds or other consideration received by Athlon with respect to such share, if any, shall be concurrently contributed to Holdings and Holdings shall issue to Athlon one New Holdings Unit.  In conjunction with the Athlon IPO, Athlon contributed net proceeds of approximately $295.7 million to Holdings and Holdings issued 15,789,474 New Holdings Units to Athlon.  In conjunction with Athlon’s public offering in April 2014, Athlon contributed net proceeds of approximately $570.8 million to Holdings and Holdings issued 14,806,250 New Holdings Units to Athlon.
	As a result of the aforementioned provision in Holdings’ Amended and Restated Agreement of Limited Partnership, Athlon’s unvested stock awards are dilutive to Holdings’ EPU calculations.  The following table reflects the allocation of net income to unitholders and EPU computations for the periods indicated:
		Three months ended June 30,					Six months ended June 30,
		2014			2013		2014			2013
		(in thousands, except per unit amounts)
	Basic EPU
	Numerator:
	Undistributed net income attributable to unitholders	$	13,496		$	28,988	$	44,665		$	39,867
	Participation rights of unvested stock awards in undistributed earnings	(138		)	—		(435		)	—
	Basic undistributed net income attributable to unitholders	$	13,358		$	28,988	$	44,230		$	39,867
	Denominator:
	Basic weighted average units outstanding	95,212			68,196		89,629			68,196
	Basic EPU attributable to unitholders	$	0.14		$	0.43	$	0.49		$	0.58
	Diluted EPU
	Numerator:
	Undistributed net income attributable to unitholders	$	13,496		$	28,988	$	44,665		$	39,867
	Participation rights of unvested stock awards in undistributed earnings	(138		)	—		(435		)	—
	Diluted undistributed net income attributable to unitholders	$	13,358		$	28,988	$	44,230		$	39,867
	Denominator:
	Diluted weighted average units outstanding	95,212			68,196		89,629			68,196
	Diluted EPU attributable to unitholders	$	0.14		$	0.43	$	0.49		$	0.58

Incentive_Stock_Plans

Incentive Stock Plans	6 Months Ended
	Jun. 30, 2014
Incentive Stock Plans	'
Incentive Stock Plans	'
	Note 10.  Incentive Stock Plans
	In August 2013, Athlon adopted the Athlon Energy Inc. 2013 Incentive Award Plan (the “Plan”).  The principal purpose of the Plan is to attract, retain, and engage selected employees, consultants, and directors through the granting of equity and equity-based compensation awards.  Employees, consultants, and directors of Athlon and its subsidiaries are eligible to receive awards under the Plan.  Athlon’s Compensation Committee will administer the Plan unless its Board of Directors assumes direct authority for administration.  The Plan provides for the grant of stock options (including non-qualified stock options and incentive stock options), restricted stock, dividend equivalents, stock payments, restricted stock units, performance awards, stock appreciation rights, and other equity-based and cash-based awards, or any combination thereof.
	The initial aggregate number of shares of common stock reserved for issuance pursuant to awards granted under the Plan is the sum of 8,400,000 shares, subject to adjustment as described below plus an annual increase on the first day of each calendar year beginning January 1, 2014 and ending on and including the last January 1 prior to the expiration date of the Plan, equal to the least of (i) 12,000,000 shares, (ii) 4% of the shares outstanding (on an as-converted basis) on the final day of the immediately preceding calendar year, and (iii) such smaller number of shares as determined by Athlon’s Board of Directors.  This number will also be adjusted due to the following shares becoming eligible to be used again for grants under the Plan:
	·         shares subject to awards or portions of awards granted under the Plan which are forfeited, expire, or lapse for any reason, or are settled for cash without the delivery of shares, to the extent of such forfeiture, expiration, lapse or cash settlement; and
	·         shares that Athlon repurchases prior to vesting so that such shares are returned to Athlon.
	On January 1, 2014, the aggregate number of shares of common stock reserved for issuance pursuant to awards granted under the Plan increased to 11,759,386.  As of June 30, 2014, there were 10,801,805 shares available for issuance under the Plan.
	The Plan does not provide for individual limits on awards that may be granted to any individual participant under the Plan.  Rather, the amount of awards to be granted to individual participants are determined by Athlon’s Board of Directors or Compensation Committee from time to time, as part of their compensation decision-making processes, provided, however, that the Plan does not permit awards having a grant date fair value in excess of $700,000 to be granted to Athlon’s non-employee directors in any year.
	During the three and six months ended June 30, 2014, Holdings recorded non-cash stock-based compensation expense related to the Plan of $4.6 million and $8.3 million, respectively, which was allocated to lease operating expense and general and administrative expense in the accompanying Consolidated Statements of Operations based on the allocation of the respective employees’ compensation.  During the three and six months ended June 30, 2014, Holdings capitalized $0.5 million and $0.8 million, respectively, of non-cash stock-based compensation expense related to the Plan as a component of “Evaluated, including wells and related equipment” in the accompanying Consolidated Balance Sheets.
	Stock awards are scheduled to vest over three years.  Certain awards granted to Athlon’s management team vest subject to the relative performance of Athlon’s common stock to that of a designated peer group.  The following table summarizes the changes in Athlon’s unvested stock awards for the six months ended June 30, 2014 (presented at the target level):
				Weighted -
				Average
		Number of		Grant Date
		Shares		Fair Value
	Outstanding at January 1	638,913		$	34.88
	Granted	330,422		37.7
	Vested	—		—
	Forfeited	(11,754	)	30.97
	Outstanding at June 30	957,581		35.9
	As of June 30, 2014, there were 957,581 unvested stock awards, 328,911 of which were granted during 2014, in which the vesting is dependent only on the passage of time and continued employment.  Additionally, as of June 30, 2014, there were 227,500 unvested stock awards, none of which were granted during 2014, in which the vesting is dependent not only on the passage of time and continued employment, but also on the relative performance of Athlon’s common stock to that of a designated peer group.
	None of Athlon’s unvested stock awards are subject to variable accounting.  As of June 30, 2014, Athlon had approximately $18.6 million of total unrecognized compensation cost related to unvested stock awards, which is expected to be recognized over a weighted-average period of approximately 2.4 years.
	Class B Interests
	Holdings’ limited partnership agreement provided for the issuance of Class B limited partner interests.  As discussed in “Note 1. Formation of the Partnership and Description of Business”, in connection with the corporate reorganization, Holdings’ Class B limited partners exchanged their interests for shares of Athlon’s common stock subject to the same conditions and vesting terms.  During the three and six months ended June 30, 2013, Holdings recorded approximately $65,000 and $113,000, respectively, of non-cash equity-based compensation expense related to Class B interests, which was allocated to lease operating expense and general and administrative expenses in the accompanying Consolidated Statements of Operations based on the allocation of the respective employees’ compensation.  During the three and six months ended June 30, 2013, Holdings capitalized approximately $17,000 and $42,000, respectively, of non-cash equity-based compensation expense related to Class B interests as a component of “Evaluated, including wells and related equipment” in the accompanying Consolidated Balance Sheets.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies	'
Commitments and Contingencies	'
	Note 11. Commitments and Contingencies
	From time to time, Holdings is a party to ongoing legal proceedings in the ordinary course of business, including workers’ compensation claims and employment-related disputes.  Management does not believe the results of these proceedings, individually or in the aggregate, will have a material adverse effect on Holdings’ business, financial position, results of operations, or liquidity.
	Additionally, Holdings has contractual obligations related to future plugging and abandonment expenses on oil and natural gas properties and related facilities disposal, long-term debt, commodity derivative contracts, operating leases, and development commitments.

Related_Party_Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2014
Related Party Transactions	'
Related Party Transactions	'
	Note 12. Related Party Transactions
	Services Agreement
	Holdings was a party to a Services Agreement, dated August 23, 2010, which required it to compensate Apollo quarterly for consulting and advisory services, subject to certain quarterly and annual limits.  The Services Agreement also provided for reimbursement to Apollo for any reasonable out-of-pocket expenses incurred while performing services under the Services Agreement.  During the three and six months ended June 30, 2013, Holdings incurred approximately $95,000 and $500,000, respectively, of advisory fees pursuant to the Services Agreement, which are included in “General and administrative expenses” in the accompanying Consolidated Statements of Operations.  Upon the consummation of the Athlon IPO, the Services Agreement was terminated.
	Exchange Agreement
	Upon the consummation of the Athlon IPO, Holdings entered into an exchange agreement with its management team and certain employees who hold New Holdings Units.  Under the exchange agreement, each such holder (and certain permitted transferees thereof) may, under certain circumstances (subject to the terms of the exchange agreement), exchange their New Holdings Units for shares of Athlon’s common stock on a one-for-one basis, subject to customary conversion rate adjustments for stock splits, stock dividends, and reclassifications.  As a holder exchanges its New Holdings Units, Athlon’s interest in Holdings will be correspondingly increased.
	Tax Receivable Agreement
	Upon the consummation of the Athlon IPO, Holdings entered into a tax receivable agreement with its management team and certain employees who hold New Holdings Units that provides for the payment from time to time by Athlon to such unitholders of Holdings of 85% of the amount of the tax benefits, if any, that Athlon is deemed to realize as a result of increases in tax basis and certain other tax benefits related to exchanges of New Holdings Units pursuant to the exchange agreement, including tax benefits attributable to payments under the tax receivable agreement.  These payment obligations are obligations of Athlon and not of Holdings.  For purposes of the tax receivable agreement, the benefit deemed realized by Athlon will be computed by comparing its actual income tax liability (calculated with certain assumptions) to the amount of such taxes that Athlon would have been required to pay had there been no increase to the tax basis of Holdings’ assets as a result of the exchanges and had Athlon not entered into the tax receivable agreement.
	The step-up in basis will depend on the fair value of the New Holdings Units at conversion.  There is no intent of the holders of New Holdings Units to exchange their units for shares of Athlon’s common stock in the foreseeable future.  In addition, Athlon does not expect to be in a regular federal income tax paying position, net of available tax credit and loss carryforwards, for the foreseeable future.  Therefore, Athlon cannot presently estimate what the benefit or payments under the tax receivable agreement will be on a factually supportable basis, and accordingly has not recognized a liability.
	Participation of Apollo Global Securities, LLC in Debt and Equity Offerings
	Apollo Global Securities, LLC is an affiliate of the Apollo Funds and received a portion of the gross spread as an initial purchaser of the 2022 Notes of $0.5 million.  Apollo Global Securities, LLC was also an underwriter in Athlon’s April 2014 common stock offering and received a portion of the discounts and commissions paid to the underwriters of approximately $1.0 million.

Subsequent_Events

Subsequent Events	6 Months Ended
	Jun. 30, 2014
Subsequent Events	'
Subsequent Events	'
	Note 13. Subsequent Events
	Subsequent to June 30, 2014, Holdings entered into additional oil swaps.  The following table summarizes Holdings’ open commodity derivative contracts as of August 21, 2014:
	Period	Average	Weighted-
		Daily Swap	Average
		Volume	Swap Price
		(Bbl)	(per Bbl)
	Q3 2014	9,950	$	92.52
	Q4 2014	10,961	92.31
	Q1 2015	12,800	92.12
	Q2 2015	12,800	92.12
	Q3 2015	11,800	93.69
	Q4 2015	11,800	93.69
	Q1 2016	2,500	92.35
	Q2 2016	2,500	92.35
	Subsequent to June 30, 2014, Holdings entered into purchase and sale agreements with multiple third parties to acquire certain oil and natural gas properties and related assets in the Midland Basin for a purchase price of $382 million, in the aggregate, subject to customary purchase price adjustments.  These acquisitions are expected to close during the third quarter of 2014, subject to customary closing conditions.

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2014
Basis of Presentation	'
New Accounting Pronouncements	'
	New Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers”.  ASU 2014-09 supersedes most of the existing revenue recognition requirements in accounting principles generally accepted in the United States (“GAAP”) and requires (i) an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration the entity expects to be entitled to in exchange for those goods or services and (ii) requires expanded disclosures regarding the nature, amount, timing, and certainty of revenue and cash flows from contracts with customers.  ASU 2014-09 is effective retrospectively for annual and interim reporting periods beginning after December 15, 2016, with early application not permitted.  Holdings is evaluating the impact, if any, that the adoption of ASU 2014-09 will have on its financial position, results of operations, and liquidity.
	No other new accounting pronouncements issued or effective from January 1, 2014 through the date of this Report, had or are expected to have a material impact on Holdings’ unaudited consolidated financial statements.

Acquisitions_Tables

Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2014
Acquisitions	'
Schedule of estimated allocation of purchase price to the fair value of assets acquired and liabilities assumed	'
		Hibernia		Piedra		Total
		(in thousands)
	Evaluated, including wells and related equipment	$	240,745	$	173,041	$	413,786
	Unevaluated	148,246		117,242		265,488
	Inventory	499		759		1,258
	Total assets acquired	389,490		291,042		680,532
	Other current liabilities	107		289		396
	Asset retirement obligations	706		536		1,242
	Total liabilities assumed	813		825		1,638
	Fair value of net assets acquired	$	388,677	$	290,217	$	678,894
Schedule of unaudited pro forma condensed financial data	'
		Three months ended June 30,				Six months ended June 30,
		2014		2013		2014		2013
		(in thousands, except per unit amounts)
	Pro forma total revenues	$	150,961	$	74,336	$	277,617	$	138,670
	Pro forma net income	$	16,880	$	22,473	$	47,308	$	27,661
	Pro forma net income per unit:
	Basic	$	0.17	$	0.27	$	0.47	$	0.33
	Diluted	$	0.17	$	0.27	$	0.47	$	0.33

Evaluated_Properties_Tables

Evaluated Properties (Tables)	6 Months Ended
	Jun. 30, 2014
Evaluated Properties	'
Schedule of Evaluated, including wells and related equipment	'
		June 30,		December 31,
		2014		2013
		(in thousands)
	Evaluated leasehold costs	$	912,321	$	448,689
	Wells and related equipment - completed	1,111,196		748,900
	Wells and related equipment - in process	47,138		46,589
	Total evaluated	$	2,070,655	$	1,244,178

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2014
Fair Value Measurements	'
Summary of open commodity derivative contracts	'
	Period	Average		Weighted-			Net Liability Fair
		Daily		Average			Market Value
		Swap		Swap Price
		Volume
		(Bbl)		(per Bbl)			(in thousands)
	Q3 2014	9,950		$	92.52
	Q4 2014	10,961		92.31
	Q3-Q4 2014	10,455		92.41			$	(20,320	)
	Q1 2015	9,800		90.9
	Q2 2015	9,800		90.9
	Q3 2015	4,300		91.11
	Q4 2015	4,300		91.11
	2015	7,027		90.97			(16,224		)
							$	(36,544	)
Summary of fair value of derivative instruments not designated as hedging instruments	'
		Oil			Commodity			Total
	Balance Sheet	Commodity			Derivatives			Commodity
	Location	Derivatives			Netting (a)			Derivatives
		(in thousands)
	As of June 30, 2014
	Assets
	Derivatives - current	$	112		$	(112	)	$	—
	Derivatives - noncurrent	318			—			318
	Total assets	430			(112		)	318
	Liabilities
	Derivatives - current	(33,654		)	112			(33,542		)
	Derivatives - noncurrent	(3,320		)	—			(3,320		)
	Total liabilities	(36,974		)	112			(36,862		)
	Net liabilities	$	(36,544	)	$	—		$	(36,544	)
	As of December 31, 2013
	Assets
	Derivatives - current	$	143		$	(143	)	$	—
	Derivatives - noncurrent	2,330			—			2,330
	Total assets	2,473			(143		)	2,330
	Liabilities
	Derivatives - current	(8,497		)	143			(8,354		)
	Derivatives - noncurrent	—			—			—
	Total liabilities	(8,497		)	143			(8,354		)
	Net liabilities	$	(6,024	)	$	—		$	(6,024	)
	(a)     Represents counterparty netting under ISDA Agreements, which allow for netting of commodity derivative contracts.  These derivative instruments are reflected net on the accompanying Consolidated Balance Sheets.
Summary of effect of derivative instruments not designated as hedges on accompanying consolidated statements of operation	'
				Amount of Loss (Gain) Recognized in Income
		Location of Loss (Gain)		Three months ended June 30,						Six months ended June 30,
	Derivatives Not Designated as Hedges	Recognized in Income		2014			2013			2014			2013
				(in thousands)
	Commodity derivative contracts	Derivative fair value loss (gain)		$	32,397		$	(12,555	)	$	43,577		$	(5,706	)
Schedule of assets and liabilities that were accounted for at fair value on a recurring basis	'
					Fair Value Measurements at Reporting Date Using
					Quoted Prices in
					Active Markets for			Significant Other			Significant
					Identical Assets			Observable Inputs			Unobservable Inputs
	Description	Net Liability			(Level 1)			(Level 2)			(Level 3)
		(in thousands)
	As of June 30, 2014
	Oil derivative contracts - swaps	$	(36,544	)	$	—		$	(36,544	)	$	—
	As of December 31, 2013
	Oil derivative contracts - swaps	$	(6,024	)	$	—		$	(6,024	)	$	—

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	6 Months Ended
	Jun. 30, 2014
Asset Retirement Obligations	'
Summary of changes in asset retirement obligations	'
	The following table summarizes the changes in Holdings’ asset retirement obligations for the six months ended June 30, 2014 (in thousands):
	Balance at January 1	$	6,855
	Liabilities assumed in acquisitions	2,177
	Liabilities incurred from new wells	867
	Liabilities settled	(103		)
	Accretion of discount	417
	Revisions of previous estimates	292
	Balance at June 30	10,505
	Less: current portion	9
	Asset retirement obligations - long term	$	10,496

LongTerm_Debt_Tables

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2014
Long-Term Debt	'
Schedule of long-term debt maturities	'
		Maturity		June 30,			December 31,
		Date		2014			2013
				(in thousands)
	Credit agreement	3/19/18		$	—		$	—
	73/8% senior notes	4/15/21		500,000			500,000
	6% senior notes	5/1/22		650,000			—
	Total			$	1,150,000		$	500,000
Schedule of quarterly commitment fee on unused portion of the Credit Agreement and applicable margin for Eurodollar and base rate loans	'
	Ratio of Outstanding Borrowings to Borrowing Base	Unused		Applicable		Applicable
		Commitment Fee		Margin for		Margin for Base
				Eurodollar Loans		Rate Loans
	Less than or equal to .30 to 1	0.375	%	1.5	%	0.5	%
	Greater than .30 to 1 but less than or equal to .60 to 1	0.375	%	1.75	%	0.75	%
	Greater than .60 to 1 but less than or equal to .80 to 1	0.5	%	2	%	1	%
	Greater than .80 to 1 but less than or equal to .90 to 1	0.5	%	2.25	%	1.25	%
	Greater than .90 to 1	0.5	%	2.5	%	1.5	%

Partners_Equity_Tables

Partners' Equity (Tables)	6 Months Ended
	Jun. 30, 2014
Partners' Equity	'
Schedule of Holdings partnership interest	'
			Partnership
			Interest
	Athlon Holdings GP LLC	General Partner	0	%
	Athlon Energy Inc.	Limited Partner	98.1	%
	Management team and certain employees	Limited Partner	1.9	%

Earnings_Per_Unit_Tables

Earnings Per Unit (Tables)	6 Months Ended
	Jun. 30, 2014
Earnings Per Unit	'
Schedule of allocation of net income to unitholders and EPU computations	'
		Three months ended June 30,					Six months ended June 30,
		2014			2013		2014			2013
		(in thousands, except per unit amounts)
	Basic EPU
	Numerator:
	Undistributed net income attributable to unitholders	$	13,496		$	28,988	$	44,665		$	39,867
	Participation rights of unvested stock awards in undistributed earnings	(138		)	—		(435		)	—
	Basic undistributed net income attributable to unitholders	$	13,358		$	28,988	$	44,230		$	39,867
	Denominator:
	Basic weighted average units outstanding	95,212			68,196		89,629			68,196
	Basic EPU attributable to unitholders	$	0.14		$	0.43	$	0.49		$	0.58
	Diluted EPU
	Numerator:
	Undistributed net income attributable to unitholders	$	13,496		$	28,988	$	44,665		$	39,867
	Participation rights of unvested stock awards in undistributed earnings	(138		)	—		(435		)	—
	Diluted undistributed net income attributable to unitholders	$	13,358		$	28,988	$	44,230		$	39,867
	Denominator:
	Diluted weighted average units outstanding	95,212			68,196		89,629			68,196
	Diluted EPU attributable to unitholders	$	0.14		$	0.43	$	0.49		$	0.58

Incentive_Stock_Plans_Tables

Incentive Stock Plans (Tables)	6 Months Ended
	Jun. 30, 2014
Incentive Stock Plans	'
Summary of changes in unvested stock awards	'
	The following table summarizes the changes in Athlon’s unvested stock awards for the six months ended June 30, 2014 (presented at the target level):
				Weighted -
				Average
		Number of		Grant Date
		Shares		Fair Value
	Outstanding at January 1	638,913		$	34.88
	Granted	330,422		37.7
	Vested	—		—
	Forfeited	(11,754	)	30.97
	Outstanding at June 30	957,581		35.9

Subsequent_Events_Tables

Subsequent Events (Tables)	6 Months Ended
	Jun. 30, 2014
Subsequent events	'
Summary of open commodity derivative contracts	'
	Period	Average	Weighted-		Net Liability Fair
		Daily	Average		Market Value
		Swap	Swap Price
		Volume
		(Bbl)	(per Bbl)		(in thousands)
	Q3 2014	9,950	$	92.52
	Q4 2014	10,961	92.31
	Q3-Q4 2014	10,455	92.41		$	(20,320	)
	Q1 2015	9,800	90.9
	Q2 2015	9,800	90.9
	Q3 2015	4,300	91.11
	Q4 2015	4,300	91.11
	2015	7,027	90.97		(16,224		)
					$	(36,544	)
Subsequent event	'
Subsequent events	'
Summary of open commodity derivative contracts	'
	The following table summarizes Holdings’ open commodity derivative contracts as of August 21, 2014:
	Period	Average	Weighted-
		Daily Swap	Average
		Volume	Swap Price
		(Bbl)	(per Bbl)
	Q3 2014	9,950	$	92.52
	Q4 2014	10,961	92.31
	Q1 2015	12,800	92.12
	Q2 2015	12,800	92.12
	Q3 2015	11,800	93.69
	Q4 2015	11,800	93.69
	Q1 2016	2,500	92.35
	Q2 2016	2,500	92.35

Formation_of_the_Partnership_a1

Formation of the Partnership and Description of Business (Details) (USD $)	0 Months Ended	6 Months Ended
In Millions, except Share data, unless otherwise specified	Aug. 07, 2013	Jun. 30, 2014
Holdings | Class A limited partners	'	'
Formation Of Partnership And Description Of Business	'	'
Total number of New Holdings Units exchangeable for common stock (in shares)	1,855,563	'
Number of common stock exchangeable against each New Holdings Unit (in shares)	'	1
Athlon Energy Inc.	'	'
Formation Of Partnership And Description Of Business	'	'
Shares of common stock issued	15,789,474	'
Per share price (in dollars per share)	20	'
Net proceeds from IPO, after deducting underwriting discounts and commissions and offering expenses (in dollars)	295.7	'
Number of common stock exchangeable against each New Holdings Unit (in shares)	'	1

Acquisitions_Details

Acquisitions (Details) (USD $)	3 Months Ended		6 Months Ended			0 Months Ended		0 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 04, 2014	Jun. 02, 2014	Jun. 30, 2014	Jun. 04, 2014	Jun. 30, 2014
						Hibernia	Hibernia	Piedra	Piedra
Acquisitions	'	'	'	'	'	'	'	'	'
Cash paid for acquisition	'	'	'	'	'	$388,700,000	'	$290,200,000	'
Transaction costs incurred	'	'	'	'	1,200,000	'	'	'	'
Allocation of the purchase price to the fair value of the assets acquired and liabilities assumed	'	'	'	'	'	'	'	'	'
Evaluated, including wells and related equipment	413,786,000	'	413,786,000	'	'	'	240,745,000	'	173,041,000
Unevaluated	265,488,000	'	265,488,000	'	'	'	148,246,000	'	117,242,000
Inventory	1,258,000	'	1,258,000	'	'	'	499,000	'	759,000
Total assets acquired	680,532,000	'	680,532,000	'	'	'	389,490,000	'	291,042,000
Other current liabilities	396,000	'	396,000	'	'	'	107,000	'	289,000
Asset retirement obligations	1,242,000	'	1,242,000	'	'	'	706,000	'	536,000
Total liabilities assumed	1,638,000	'	1,638,000	'	'	'	813,000	'	825,000
Fair value of net assets acquired	678,894,000	'	678,894,000	'	'	'	388,677,000	'	290,217,000
Unaudited pro forma condensed financial data	'	'	'	'	'	'	'	'	'
Pro forma total revenues	150,961,000	74,336,000	277,617,000	138,670,000	'	'	'	'	'
Pro forma net income	$16,880,000	$22,473,000	$47,308,000	$27,661,000	'	'	'	'	'
Pro forma net income per common unit:	'	'	'	'	'	'	'	'	'
Basic (in dollar per share)	$0.17	$0.27	$0.47	$0.33	'	'	'	'	'
Diluted (in dollar per share)	$0.17	$0.27	$0.47	$0.33	'	'	'	'	'

Evaluated_Properties_Details

Evaluated Properties (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Evaluated, including wells and related equipment	'	'
Evaluated leasehold costs	$912,321	$448,689
Wells and related equipment - completed	1,111,196	748,900
Wells and related equipment - in process	47,138	46,589
Total evaluated properties	$2,070,655	$1,244,178

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013	Apr. 30, 2013	Jun. 30, 2014	1-May-14	Jun. 30, 2014	Jun. 30, 2014
In Millions, unless otherwise specified	2021 Notes	2021 Notes	2021 Notes	2022 Notes	2022 Notes	Level 1 input	Level 1 input
						2021 Notes	2022 Notes
Fair value measurements	'	'	'	'	'	'	'
Interest rate (as a percent)	7.38%	7.38%	7.38%	6.00%	6.00%	'	'
Senior notes	'	'	'	'	'	$547.50	$674.40

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Open commodity derivative contracts	'	'
Summary of open commodity derivative contracts	'	'
Net liability Fair Market Value	($36,544)	($6,024)
Open commodity derivative contracts | Q3-Q4 2014	'	'
Summary of open commodity derivative contracts	'	'
Net liability Fair Market Value	-20,320	'
Open commodity derivative contracts | 2015	'	'
Summary of open commodity derivative contracts	'	'
Net liability Fair Market Value	($16,224)	'
Commodity derivative contracts with swap price | Q3 2014	'	'
Summary of open commodity derivative contracts	'	'
Average Daily Swap Volume	9,950	'
Weighted-Average Swap Price	92.52	'
Commodity derivative contracts with swap price | Q4 2014	'	'
Summary of open commodity derivative contracts	'	'
Average Daily Swap Volume	10,961	'
Weighted-Average Swap Price	92.31	'
Commodity derivative contracts with swap price | Q3-Q4 2014	'	'
Summary of open commodity derivative contracts	'	'
Average Daily Swap Volume	10,455	'
Weighted-Average Swap Price	92.41	'
Commodity derivative contracts with swap price | Q1 2015	'	'
Summary of open commodity derivative contracts	'	'
Average Daily Swap Volume	9,800	'
Weighted-Average Swap Price	90.9	'
Commodity derivative contracts with swap price | Q2 2015	'	'
Summary of open commodity derivative contracts	'	'
Average Daily Swap Volume	9,800	'
Weighted-Average Swap Price	90.9	'
Commodity derivative contracts with swap price | Q3 2015	'	'
Summary of open commodity derivative contracts	'	'
Average Daily Swap Volume	4,300	'
Weighted-Average Swap Price	91.11	'
Commodity derivative contracts with swap price | Q4 2015	'	'
Summary of open commodity derivative contracts	'	'
Average Daily Swap Volume	4,300	'
Weighted-Average Swap Price	91.11	'
Commodity derivative contracts with swap price | 2015	'	'
Summary of open commodity derivative contracts	'	'
Average Daily Swap Volume	7,027	'
Weighted-Average Swap Price	90.97	'

Fair_Value_Measurements_Detail2

Fair Value Measurements (Details 3) (Commodity contracts, USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Liabilities	'	'
Net assets (liabilities)	($36,544)	($6,024)
Derivative instruments not designated as hedging instruments | Oil	'	'
Assets	'	'
Oil Commodity Derivatives, assets	430	2,473
Commodity Derivatives Netting, assets	-112	-143
Total Commodity Derivatives	318	2,330
Liabilities	'	'
Oil Commodity Derivatives, liabilities	-36,974	-8,497
Commodity Derivatives Netting, liabilities	112	143
Total Commodity Derivatives	-36,862	-8,354
Net assets (liabilities)	-36,544	-6,024
Derivative instruments not designated as hedging instruments | Oil | Derivative assets - current	'	'
Assets	'	'
Oil Commodity Derivatives, assets	112	143
Commodity Derivatives Netting, assets	-112	-143
Derivative instruments not designated as hedging instruments | Oil | Derivative assets - noncurrent	'	'
Assets	'	'
Oil Commodity Derivatives, assets	318	2,330
Total Commodity Derivatives	318	2,330
Derivative instruments not designated as hedging instruments | Oil | Derivative liabilities - current	'	'
Liabilities	'	'
Oil Commodity Derivatives, liabilities	-33,654	-8,497
Commodity Derivatives Netting, liabilities	112	143
Total Commodity Derivatives	-33,542	-8,354
Derivative instruments not designated as hedging instruments | Oil | Derivative liabilities - noncurrent	'	'
Liabilities	'	'
Oil Commodity Derivatives, liabilities	-3,320	'
Total Commodity Derivatives	($3,320)	'

Fair_Value_Measurements_Detail3

Fair Value Measurements (Details 4) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Fair value measurements	'	'	'	'
Amount of Loss (Gain) Recognized in Income	$32,397	($12,555)	$43,577	($5,706)
Derivative instruments not designated as hedges | Commodity contracts | Derivative fair value loss (gain)	'	'	'	'
Fair value measurements	'	'	'	'
Amount of Loss (Gain) Recognized in Income	$32,397	($12,555)	$43,577	($5,706)

Fair_Value_Measurements_Detail4

Fair Value Measurements (Details 5) (Commodity contracts, USD $)	Jun. 30, 2014	Dec. 31, 2013
Fair Value Hierarchy	'	'
Decrease in net commodity derivative liabilities	$630,000	$39,000
Recurring | Net Liability | Oil | Swaps	'	'
Fair Value Hierarchy	'	'
Net assets (liabilities)	-36,544,000	-6,024,000
Recurring | Significant Other Observable Inputs (Level 2) | Oil | Swaps	'	'
Fair Value Hierarchy	'	'
Net assets (liabilities)	($36,544,000)	($6,024,000)

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Asset retirement obligations	'	'	'	'	'
Balance at the beginning of the period	'	'	$6,855	'	'
Liabilities assumed in acquisitions	'	'	2,177	'	'
Liabilities incurred from new wells	'	'	867	'	'
Liabilities settled	'	'	-103	'	'
Accretion of discount	222	162	417	311	'
Revisions of previous estimates	'	'	292	'	'
Balance at the end of the period	10,505	'	10,505	'	'
Less: current portion	9	'	9	'	'
Asset retirement obligations - long-term	$10,496	'	$10,496	'	$6,795

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Mar. 19, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Dec. 31, 2013

Apr. 30, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

1-May-14

Jun. 30, 2014

1-May-14

1-May-14

1-May-14

1-May-14

1-May-14

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Credit agreement

Senior notes

2021 Notes

2021 Notes

2021 Notes

2021 Notes

2021 Notes

2021 Notes

2021 Notes

2022 Notes

2022 Notes

2022 Notes

2022 Notes

2022 Notes

2022 Notes

2022 Notes

Applicable Margin for Eurodollar Loans

Applicable Margin for Eurodollar Loans

Applicable Margin for Base Rate Loans

Applicable Margin for Base Rate Loans

Applicable Margin for Base Rate Loans

Applicable Margin for Base Rate Loans

Applicable Margin for Base Rate Loans

Less than or equal to .30 to 1

Less than or equal to .30 to 1

Less than or equal to .30 to 1

Greater than .30 to 1 but less than or equal to .60 to 1

Greater than .30 to 1 but less than or equal to .60 to 1

Greater than .30 to 1 but less than or equal to .60 to 1

Greater than .60 to 1 but less than or equal to .80 to 1

Greater than .60 to 1 but less than or equal to .80 to 1

Greater than .60 to 1 but less than or equal to .80 to 1

Greater than .80 to 1 but less than or equal to .90 to 1

Greater than .80 to 1 but less than or equal to .90 to 1

Greater than .80 to 1 but less than or equal to .90 to 1

Greater than .90 to 1

Greater than .90 to 1

Greater than .90 to 1

Maximum

Maximum

Maximum

Maximum

Minimum

Minimum

Minimum

Minimum

Maximum

Upon assets disposition triggering events

Prior to April 15, 2016

Prior to April 15, 2016

Maximum

Prior to May 1, 2017

Prior to May 1, 2017

On or prior to July 15, 2015

On or prior to July 15, 2015

Maximum

Eurodollar rate

LIBOR

Eurodollar rate

LIBOR

Base Rate

Prime rate

Federal funds rate

Applicable Margin for Eurodollar Loans

Applicable Margin for Base Rate Loans

Applicable Margin for Eurodollar Loans

Applicable Margin for Base Rate Loans

Applicable Margin for Eurodollar Loans

Applicable Margin for Base Rate Loans

Applicable Margin for Eurodollar Loans

Applicable Margin for Base Rate Loans

Applicable Margin for Eurodollar Loans

Applicable Margin for Base Rate Loans

Less than or equal to .30 to 1

Greater than .30 to 1 but less than or equal to .60 to 1

Greater than .60 to 1 but less than or equal to .80 to 1

Greater than .80 to 1 but less than or equal to .90 to 1

Greater than .30 to 1 but less than or equal to .60 to 1

Greater than .60 to 1 but less than or equal to .80 to 1

Greater than .80 to 1 but less than or equal to .90 to 1

Greater than .90 to 1

Redemption from proceeds of certain equity offerings

Prior to April 15, 2016

Redemption from proceeds of certain equity offerings

Redemption of debt instrument upon change of control

Upon assets disposition triggering events

Prior to May 1, 2017

Redemption from proceeds of certain equity offerings

Redemption from proceeds of certain equity offerings

Long-term debt

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

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'

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'

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'

'

Aggregate principal amount of notes issued

$1,150,000,000

$500,000,000

'

'

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'

$500,000,000

$500,000,000

$500,000,000

'

'

'

'

$650,000,000

$650,000,000

'

'

'

'

'

Interest rate (as a percent)

'

'

'

'

'

'

'

'

'

'

'

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'

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'

'

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7.38%

7.38%

7.38%

'

'

'

'

6.00%

6.00%

'

'

'

'

'

Percentage of aggregate principal amount of notes that can be redeemed

'

'

'

'

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35.00%

'

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'

'

35.00%

Redemption price of debt instrument (as a percent)

'

'

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'

'

101.00%

100.00%

107.38%

'

'

'

100.00%

106.00%

110.00%

101.00%

'

Fixed charge coverage ratio

'

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'

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'

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2

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'

'

Net proceeds from the issuance of senior notes due 2022

'

'

'

'

'

'

'

'

'

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'

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'

'

639,100,000

'

'

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'

'

Maximum amount committed by lender

'

'

'

1,000,000,000

'

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Current borrowing capacity

'

'

837,500,000

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Outstanding borrowings

'

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0

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Outstanding letters of credit

'

'

$0

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Ratio of Outstanding Borrowings to Borrowing Base

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

30.00%

60.00%

80.00%

90.00%

30.00%

60.00%

80.00%

90.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unused Commitment Fee (as a percent)

'

'

'

'

'

'

'

'

'

'

'

0.38%

'

'

0.38%

'

'

0.50%

'

'

0.50%

'

'

0.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Applicable Margin (as a percent)

'

'

'

'

'

'

1.00%

'

'

'

0.50%

'

1.50%

0.50%

'

1.75%

0.75%

'

2.00%

1.00%

'

2.25%

1.25%

'

2.50%

1.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Variable interest rate base

'

'

'

'

'Eurodollar rate

'LIBOR

'Eurodollar rate

'LIBOR

'Base Rate

'prime rate

'Federal fund

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ratio of consolidated total debt to EBITDAX beginning with quarter ended June 30, 2014

'

'

4.5

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum projected production that can be hedged (as a percent)

'

'

85.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Period over which hedging limitation requirement of the projected production from proved reserve is required to be maintained

'

'

'66 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Partners_Equity_Details

Partners' Equity (Details) (USD $)	0 Months Ended	6 Months Ended
In Millions, except Share data, unless otherwise specified	Apr. 23, 2014	Jun. 30, 2014	Aug. 07, 2013
Athlon Holdings GP LLC	'	'	'
Partners' Equity	'	'	'
General partner ownership interest (as a percent)	'	0.00%	'
Athlon Energy Inc.	'	'	'
Partners' Equity	'	'	'
Shares of common stock issued	14,806,250	'	'
Per share price (in dollars per share)	$40	'	$20
Net proceeds from public offering, after deducting underwriting discounts and commissions and offering expenses (in dollars)	$570.80	'	'
Limited partner ownership interest (as a percent)	'	98.10%	'
Management team and certain employees	'	'	'
Partners' Equity	'	'	'
Limited partner ownership interest (as a percent)	'	1.90%	'

Earnings_Per_Unit_Details

Earnings Per Unit (Details) (USD $)	6 Months Ended	0 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Apr. 29, 2014	Aug. 07, 2013	Apr. 30, 2013	Apr. 30, 2014	Apr. 23, 2014	Aug. 07, 2013
		Holdings	Holdings	Holdings	Holdings	Athlon Energy Inc.	Athlon Energy Inc.
Earnings per unit	'	'	'	'	'	'	'
Outstanding limited partner units prior to consummation of Athlon IPO	'	'	'	989,508	'	'	'
Issue price of IPO (in dollars per share)	'	'	'	'	'	$40	$20
Stock split ratio	'	'	65.266	'	'	'	'
Outstanding limited partner units prior to closing of Athlon IPO	'	'	68,195,178	'	'	'	'
Conversion of units into common stock (in units)	'	'	'	1	'	'	'
Net contributions from Athlon Energy Inc.	$567,606	$570,800	$295,700	'	'	'	'
New holdings units issued	'	'	15,789,474	'	14,806,250	'	'

Earnings_Per_Unit_Details_2

Earnings Per Unit (Details 2) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Numerator	'	'	'	'
Undistributed net income attributable to unitholders	$13,496	$28,988	$44,665	$39,867
Participation rights of unvested stock awards in undistributed earnings	-138	'	-435	'
Basic undistributed net income attributable to unitholders	13,358	28,988	44,230	39,867
Denominator	'	'	'	'
Basic weighted average units outstanding	95,212	68,196	89,629	68,196
Basic EPU attributable to unitholders (in dollars per unit)	$0.14	$0.43	$0.49	$0.58
Numerator	'	'	'	'
Undistributed net income attributable to unitholders	13,496	28,988	44,665	39,867
Participation rights of unvested stock awards in undistributed earnings	-138	'	-435	'
Diluted undistributed net income attributable to unitholders	$13,358	$28,988	$44,230	$39,867
Denominator	'	'	'	'
Diluted weighted average units outstanding	95,212	68,196	89,629	68,196
Diluted EPU attributable to unitholders (in dollars per unit)	$0.14	$0.43	$0.49	$0.58

Incentive_Stock_Plans_Details

Incentive Stock Plans (Details) (USD $)

6 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Aug. 31, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2013

Athlon Energy Inc.

Athlon Energy Inc.

Athlon Energy Inc.

Athlon Energy Inc.

Athlon Energy Inc.

Athlon Energy Inc.

Athlon Energy Inc.

Holdings

Holdings

Holdings

Holdings

2013 Incentive Award Plan

2013 Incentive Award Plan

2013 Incentive Award Plan

2013 Incentive Award Plan

2013 Incentive Award Plan

Maximum

Maximum

2013 Incentive Award Plan

2013 Incentive Award Plan

Class B limited partners

Class B limited partners

Stock Awards

Stock Awards

Stock Awards

2013 Incentive Award Plan

2013 Incentive Award Plan

Vesting of awards subject to time and continued employment condition

Vesting of awards subject to time, continued employment and performance condition

Non-employee directors

Incentive stock plans

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate shares of common stock available for issuance under the 2013 stock incentive plan

'

'

11,759,386

8,400,000

'

'

'

'

'

'

'

'

'

Aggregate shares of common stock available for issuance under the 2013 stock incentive plan at January 1, 2014 under the first condition

'

'

'

'

'

'

'

12,000,000

'

'

'

'

'

Percentage increase to shares of common stock available for issuance under the 2013 stock incentive plan at January 1, 2014 under the second condition

'

'

'

'

'

'

'

4.00%

'

'

'

'

'

Remaining shares available for grant

'

'

10,801,805

'

'

'

'

'

'

'

'

'

'

Grant date fair value of awards

'

'

'

'

'

'

'

'

$700,000

'

'

'

'

Non-cash equity-based compensation expense

8,267,000

113,000

'

'

'

'

'

'

'

4,600,000

8,300,000

65,000

113,000

Capitalized non-cash equity-based compensation expense

'

'

'

'

'

'

'

'

'

500,000

800,000

17,000

42,000

Vesting period of restricted stock awards

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

Unvested restricted stock

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding at beginning of the period (in shares)

'

'

'

'

638,913

'

'

'

'

'

'

'

'

Granted (in shares)

'

'

'

'

330,422

328,911

0

'

'

'

'

'

'

Forfeited (in shares)

'

'

'

'

-11,754

'

'

'

'

'

'

'

'

Outstanding at end of the period (in shares)

'

'

'

'

957,581

'

'

'

'

'

'

'

'

Weighted - Average Grant Date Fair Value

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding at beginning of period (in dollars per share)

'

'

'

'

$34.88

'

'

'

'

'

'

'

'

Granted (in dollars per share)

'

'

'

'

$37.70

'

'

'

'

'

'

'

'

Forfeited (in dollars per share)

'

'

'

'

$30.97

'

'

'

'

'

'

'

'

Outstanding at end of the period (in dollars per share)

'

'

'

'

$35.90

'

'

'

'

'

'

'

'

Additional disclosure

'

'

'

'

'

'

'

'

'

'

'

'

'

Unvested restricted stock granted, vesting of which is dependent on passage of specified time and continued employment condition (in shares)

'

'

'

'

'

957,581

'

'

'

'

'

'

'

Unvested restricted stock granted, vesting of which is dependent on passage of specified time and continued employment and also on performance condition (in shares)

'

'

'

'

'

'

227,500

'

'

'

'

'

'

Unvested restricted stock subject to variable accounting (in shares)

'

'

'

'

0

'

'

'

'

'

'

'

'

Total unrecognized compensation cost related to unvested restricted stock

'

'

'

'

$18,600,000

'

'

'

'

'

'

'

'

Weighted-average period for recognition of unrecognized compensation cost

'

'

'

'

'2 years 4 months 24 days

'

'

'

'

'

'

'

'

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	6 Months Ended				3 Months Ended	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014	1-May-14	Jun. 30, 2013	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2014
			2022 Notes	2022 Notes	Apollo	Apollo	Management team and certain employees	Apollo funds	Apollo funds
									2022 Notes
Related party transactions	'	'	'	'	'	'	'	'	'
Advisory fees pursuant to the Services Agreement	'	'	'	'	$95,000	$500,000	'	'	'
Number of common stock exchangeable against each New Holdings Unit	'	'	'	'	'	'	1	'	'
Percentage of income tax benefits distributable to holders of New Holdings Units	85.00%	'	'	'	'	'	'	'	'
Received a portion of the gross spread as an initial purchaser of notes issued	1,150,000,000	500,000,000	650,000,000	650,000,000	'	'	'	'	500,000
Payment of discounts and commissions to underwriters	'	'	'	'	'	'	'	$1,000,000	'

Subsequent_Events_Details

Subsequent Events (Details) (USD $)

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Aug. 21, 2014

Aug. 21, 2014

Aug. 21, 2014

Aug. 21, 2014

Aug. 21, 2014

Aug. 21, 2014

Aug. 21, 2014

Aug. 21, 2014

In Millions, unless otherwise specified

Commodity derivative contracts with swap price

Commodity derivative contracts with swap price

Commodity derivative contracts with swap price

Commodity derivative contracts with swap price

Commodity derivative contracts with swap price

Commodity derivative contracts with swap price

Subsequent event

Subsequent event

Subsequent event

Subsequent event

Subsequent event

Subsequent event

Subsequent event

Subsequent event

Subsequent event

Q3 2014

Q4 2014

Q1 2015

Q2 2015

Q3 2015

Q4 2015

Midland Basin

Commodity derivative contracts with swap price

Commodity derivative contracts with swap price

Commodity derivative contracts with swap price

Commodity derivative contracts with swap price

Commodity derivative contracts with swap price

Commodity derivative contracts with swap price

Commodity derivative contracts with swap price

Commodity derivative contracts with swap price

bbl

bbl

bbl

bbl

bbl

bbl

Q3 2014

Q4 2014

Q1 2015

Q2 2015

Q3 2015

Q4 2015

Q1 2016

Q2 2016

bbl

bbl

bbl

bbl

bbl

bbl

bbl

bbl

Subsequent events

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Average Daily Swap Volume

9,950

10,961

9,800

9,800

4,300

4,300

'

9,950

10,961

12,800

12,800

11,800

11,800

2,500

2,500

Weighted-Average Swap Price

92.52

92.31

90.9

90.9

91.11

91.11

'

92.52

92.31

92.12

92.12

93.69

93.69

92.35

92.35

Purchase price

'

'

'

'

'

'

$382

'

'

'

'

'

'

'

'