Foresight Energy (FELPQ) 10-Q 7 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Nov. 03, 2014	Nov. 03, 2014
		Common Units	Subordinated Units
Document And Entity Information [Line Items]	'	'	'
Entity Registrant Name	'Foresight Energy LP	'	'
Entity Central Index Key	'0001540729	'	'
Document Type	'10-Q	'	'
Document Period End Date	30-Sep-14	'	'
Amendment Flag	'false	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Non-accelerated Filer	'	'
Document Fiscal Year Focus	'2014	'	'
Document Fiscal Period Focus	'Q3	'	'
Entity Units Outstanding	'	64,786,275	64,738,895

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$24,771	$23,284
Accounts receivable	92,645	58,987
Due from affiliates	259	368
Inventories	98,487	71,290
Prepaid expenses	3,494	3,028
Prepaid royalties	12,010	6,330
Deferred longwall costs	24,025	14,265
Coal derivative assets	19,942	1,976
Other current assets	6,809	6,568
Total current assets	282,442	186,096
Property, plant, equipment and development, net	1,447,725	1,414,074
Prepaid royalties	71,005	73,242
Coal derivative assets	17,228	912
Other assets	28,083	35,847
Total assets	1,846,483	1,710,171
Current liabilities:	'	'
Current portion of long-term debt and capital lease obligations	34,471	70,034
Accrued interest	16,979	27,645
Accounts payable	70,076	50,155
Accrued expenses and other current liabilities	38,560	37,515
Due to affiliates	15,665	9,572
Total current liabilities	175,751	194,921
Long-term debt and capital lease obligations	1,302,714	1,449,179
Sale-leaseback financing arrangements	193,434	193,434
Asset retirement obligations	20,859	20,416
Other long-term liabilities	3,876	337
Total liabilities	1,696,634	1,858,287
Limited partners' capital (deficit):	'	'
Total limited partners' capital	142,832	'
Total partners' capital (deficit)	149,849	-148,116
Noncontrolling interests	7,017	9,240
Total liabilities and partners' capital (deficit)	1,846,483	1,710,171
Common Units	'	'
Limited partners' capital (deficit):	'	'
Total limited partners' capital	245,864	'
Subordinated Units	'	'
Limited partners' capital (deficit):	'	'
Total limited partners' capital	-103,032	'
Predecessor	'	'
Limited partners' capital (deficit):	'	'
Total partners' capital (deficit)	'	($157,356)

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical)	Sep. 30, 2014
In Thousands, unless otherwise specified
Common Units	'
Capital units, Outstanding	64,786
Subordinated Units	'
Capital units, Outstanding	64,739

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Coal sales	$299,964	$240,868	$809,365	$689,391
Costs and expenses:	'	'	'	'
Cost of coal produced (excluding depreciation, depletion and amortization)	123,535	97,376	323,064	255,825
Cost of coal purchased	11,940	'	12,672	2,163
Transportation	55,491	43,341	164,661	138,989
Depreciation, depletion and amortization	45,953	40,639	121,903	115,065
Accretion on asset retirement obligations	405	382	1,215	1,145
Selling, general and administrative	6,398	10,767	26,632	28,984
Gain on coal derivatives	-18,990	-1,200	-41,419	-1,880
Other operating loss (income), net	875	75	-1,414	264
Operating income	74,357	49,488	202,051	148,836
Other expenses:	'	'	'	'
Loss on early extinguishment of debt	'	77,755	4,979	77,755
Interest expense, net	28,202	29,566	88,156	85,527
Net income (loss)	46,155	-57,833	108,916	-14,446
Less: net income attributable to noncontrolling interests	789	804	2,772	1,010
Net income (loss) attributable to controlling interests	45,366	-58,637	106,144	-15,456
Less: predecessor net income attributable to controlling interests prior to initial public offering	'	'	65,008	'
Net income subsequent to initial public offering attributable to limited partner units (June 23, 2014 through September 30, 2014)	'	'	41,136	'
Weighted average limited partner units outstanding - basic and diluted:	'	'	'	'
Distribution declared per limited partner unit	$0.03	'	$0.03	'
Subordinated Units	'	'	'	'
Other expenses:	'	'	'	'
Net income subsequent to initial public offering attributable to limited partner units (June 23, 2014 through September 30, 2014)	22,675	'	20,517	'
Net income subsequent to initial public offering available to limited partner units - basic and diluted:	'	'	'	'
Net income subsequent to initial public offering per limited partner unit - basic and diluted	$0.35	'	$0.32	'
Weighted average limited partner units outstanding - basic and diluted:	'	'	'	'
Weighted average limited partner units outstanding - basic and diluted	64,739	'	64,739	'
Common Units	'	'	'	'
Other expenses:	'	'	'	'
Net income subsequent to initial public offering attributable to limited partner units (June 23, 2014 through September 30, 2014)	$22,691	'	$20,619	'
Net income subsequent to initial public offering available to limited partner units - basic and diluted:	'	'	'	'
Net income subsequent to initial public offering per limited partner unit - basic and diluted	$0.35	'	$0.32	'
Weighted average limited partner units outstanding - basic and diluted:	'	'	'	'
Weighted average limited partner units outstanding - basic and diluted	64,786	'	64,786	'

Condensed_Consolidated_Stateme1

Condensed Consolidated Statement of Partners Capital and Members Deficit (USD $)	Total	Noncontrolling Interests	Predecessor	Limited Partners	Limited Partners
In Thousands				Common Units	Subordinated Units
Beginning Balance at Dec. 31, 2013	($148,116)	$9,240	($157,356)	'	'
Net income prior to initial public offering	66,789	1,781	65,008	'	'
Non-cash distributions	-12,187	'	-12,187	'	'
Contribution of net assets to Foresight Energy LP	'	'	104,878	-51,354	-53,524
Issuance of common units, net of offering costs	322,755	'	'	322,755	'
Cash distributions	-124,225	-4,995	-343	-48,862	-70,025
Net income subsequent to initial public offering	42,127	991	'	20,619	20,517
Equity-based compensation	3,257	'	'	3,257	'
Net settlement of withholding taxes on issued unit awards	-551	'	'	-551	'
Ending Balance at Sep. 30, 2014	$149,849	$7,017	'	$245,864	($103,032)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities	'	'
Net income (loss)	$108,916	($14,446)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	121,903	115,065
Equity-based compensation	3,257	'
Amortization of debt issuance costs and debt premium/discount	5,388	5,582
Unrealized gain on coal derivatives	-33,711	-1,428
Deferred revenue recognized	-174	-3,907
Non-cash loss on early extinguishment of debt	4,681	5,625
Other	2,332	3,594
Changes in operating assets and liabilities:	'	'
Accounts receivable	-33,658	17,228
Due from/to affiliates, net	6,219	-2,115
Inventories	-19,120	-15,225
Prepaid expenses and other current assets	-10,467	-10,475
Prepaid royalties	-3,443	-611
Coal derivative assets and liabilities	-908	-893
Accounts payable	19,767	4,140
Accrued interest	-10,666	-9,679
Accrued expenses and other current liabilities	4,148	15,066
Deferred revenue	349	10,066
Other	-651	-867
Net cash provided by operating activities	164,162	116,720
Cash flows from investing activities	'	'
Investment in property, plant, equipment and development	-173,609	-128,894
Acquisition of an affiliate	-3,822	'
Proceeds from sale of equipment	1,619	393
Settlement of coal derivatives	'	986
Net cash used in investing activities	-175,812	-127,515
Cash flows from financing activities	'	'
Net increase in borrowings under revolving credit facility	83,500	23,000
Proceeds from other long-term debt	29,719	1,041,156
Payments on other long-term debt and capital lease obligations	-297,908	-619,922
Distributions paid	-124,225	-410,361
Proceeds from issuance of common units (net of underwriters' discount)	329,875	'
Initial public offering costs paid (other than underwriters' discount)	-6,976	-72
Debt issuance costs paid	-297	-23,259
Net settlement of withholding taxes on issued unit awards	-551	'
Net cash provided by financing activities	13,137	10,542
Net increase (decrease) in cash and cash equivalents	1,487	-253
Cash and cash equivalents, beginning of period	23,284	27,888
Cash and cash equivalents, end of period	24,771	27,635
Supplemental information:	'	'
Interest paid, net of amounts capitalized	93,437	89,613
Supplemental disclosures of non-cash financing activities:	'	'
Non-cash distributions	$12,187	$61,990

Organization_Nature_of_Busines

Organization, Nature of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'
Organization, Nature of Business and Basis of Presentation	'
	1. Organization, Nature of Business and Basis of Presentation
	As used in this report, the terms “Foresight Energy LP,” “FELP,” the “Partnership,” “we,” “us” or like terms, refer to Foresight Energy LP and our consolidated subsidiaries and affiliates. The information presented in this Quarterly Report on Form 10-Q contains the unaudited combined financial results of Foresight Energy LLC (“FELLC”), our predecessor for accounting purposes (the “Predecessor”), and variable interest entities (“VIEs”) for which FELLC or its subsidiaries are the primary beneficiary, for all periods presented through September 30, 2014. The consolidated financial results also include the results of operations of the Partnership for the period beginning June 23, 2014, the date of the contribution of the Predecessor’s net assets to the Partnership.
	FELLC, a perpetual-term Delaware limited liability company, was formed in September 2006 for the development, mining, transportation and sale of coal. Prior to June 23, 2014, Foresight Reserves, LP (“Foresight Reserves”) owned 99.333% of FELLC and a member of management owned 0.667%. In January 2012, Foresight Energy LP (formerly named Foresight Energy Partners LP), a Delaware limited partnership, and Foresight Energy GP LLC (“general partner”), a Delaware limited liability company, were formed. FELP was formed to own FELLC and Foresight Energy GP LLC was formed to be the general partner of FELP. Prior to June 23, 2014, FELP had no operating or cash flow activity, and no recorded net assets.
	On June 23, 2014, in connection with the initial public offering of FELP, Foresight Reserves and a member of management contributed their ownership interests in FELLC to FELP for which they were issued common and subordinated units in FELP. Because this transaction was between entities under common control, the contributed assets and liabilities of FELLC were recorded in the consolidated financial statements at FELLC’s historical cost. See Note 3 for information regarding our initial public offering.
	The Partnership operates in a single reportable segment and currently operates four underground mining complexes in the Illinois Basin: Williamson Energy, LLC (“Williamson”); Sugar Camp Energy, LLC (“Sugar Camp”); Hillsboro Energy, LLC (“Hillsboro”); and Macoupin Energy, LLC (“Macoupin”). Effective June 1, 2014, the second longwall system at our Sugar Camp complex transitioned from the development stage to the production stage and from that date forward was recognized in our results of operations. Mined coal is sold to a diverse customer base, including electric utility and industrial companies primarily in the eastern United States, as well as overseas markets. Intercompany transactions, including those between consolidated VIEs, FELP and its consolidated subsidiaries, are eliminated in consolidation.
	The accompanying unaudited condensed consolidated financial statements contain all significant adjustments (consisting of normal recurring accruals) that, in the opinion of management, are necessary to present fairly the Partnership’s consolidated financial position, consolidated results of operations and consolidated cash flows for all periods presented. In preparing the unaudited condensed consolidated financial statements, management used estimates and assumptions that may affect reported amounts and disclosures. To the extent there are material differences between the estimates and actual results, the impact to the Partnership’s financial condition or results of operations could be material. The unaudited condensed consolidated financial statements do not include footnotes and certain financial information as required annually under US generally accepted accounting principles (“US GAAP”) and, therefore, should be read in conjunction with the annual audited consolidated financial statements for the year ended December 31, 2013 included in our prospectus filed with the SEC on June 19, 2014. The results of operations for the three and nine months ended September 30, 2014 are not necessarily indicative of results that can be expected for any future period, including the year ending December 31, 2014.

New_Accounting_Standards

New Accounting Standards	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
New Accounting Standards	'
	2. New Accounting Standards
	New Accounting Standards Issued and Not Yet Adopted
	In April 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. ASU 2014-08 changes the requirements for reporting discontinued operations by updating the criteria for determining discontinued operations and modifies the disclosure requirements of both discontinued operations and certain other disposals not defined as discontinued operations. ASU 2014-08 is effective for annual and interim periods beginning after December 15, 2014 and we do not expect it will have a material impact on our consolidated financial statements.
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, to clarify the principles used to recognize revenue. The guidance is effective for annual and interim periods beginning after December 15, 2016. Early adoption is not permitted. We will evaluate the effects, if any, the adoption of this guidance will have on our consolidated financial statements.
	In August 2014, the FASB issued ASU 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which requires management of a company to evaluate whether there is substantial doubt about the company’s ability to continue as a going concern. This ASU is effective for the annual reporting period ending after December 15, 2016, with early adoption permitted. This standard is not currently expected to have a material effect on the Partnership's financial statement disclosures, though the ultimate impact will be dependent on the Partnership's financial condition and expected operating outlook.

Initial_Public_Offering

Initial Public Offering	9 Months Ended
	Sep. 30, 2014
Initial Public Offering [Abstract]	'
Initial Public Offering	'
	3. Initial Public Offering
	On June 18, 2014, the Partnership’s common units began trading on the New York Stock Exchange (“NYSE”) under the symbol “FELP.” Upon the closing of the initial public offering (“IPO”) on June 23, 2014, the following transactions occurred:
	—	Foresight Reserves and a member of management each contributed their membership interests in FELLC to the Partnership;
	—	The Partnership issued to Foresight Reserves and a member of management, on a pro rata basis, an aggregate of 44,613,895 common units and 64,738,895 subordinated units;
	—	The Partnership issued to our general partner, which is owned 99.333% by Foresight Reserves and 0.667% by a member of management, incentive distribution rights.  The incentive distribution rights entitle the holder to an increasing percentage, up to a maximum of 50%, of the cash the Partnership distributes in excess of $0.3881 per unit per quarter (see Note 4);
	—	The Partnership issued 17,500,000 units to the public at $20.00 per unit; and
	—	The $329.9 million of proceeds received from the sale of common units to the public, net of underwriters’ discount of $20.1 million, were used to repay $210.0 million of principal on the term loan and to pay a $115.0 million distribution to Foresight Reserves and a member of management, on a pro rata basis. As of September 30, 3014, we incurred an additional $7.1 million in other offering costs which were recorded against partners’ capital.
	In July 2014, the underwriters’ overallotment option expired, resulting in an additional 2,625,000 units being issued, on a pro rata basis, to Foresight Reserves and a member of management for no additional consideration. After the issuance of these overallotment units in July 2014, the common units held by the public represented 13.5% of the outstanding limited partnership interest.

Partners_Capital

Partners' Capital	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Partners' Capital	'
	4. Partners’ Capital
	Common and Subordinated Units
	All subordinated units are currently held by Foresight Reserves and a member of management. The principal difference between our common units and subordinated units is that subordinated unitholders are not entitled to receive a distribution of available cash until the holders of common units have received the minimum quarterly distribution (“MQD”).  The MQD is $0.3375 per unit for such quarter plus any cumulative arrearages of previously unpaid MQDs from previous quarters. Also, subordinated unitholders are not entitled to receive arrearages. The subordination period will end, and the subordinated units will convert to common units, on a one-for-one basis, on the first business day after the Partnership has paid the MQD for each of three consecutive, non-overlapping four-quarter periods ending on or after March 31, 2017 and there are no outstanding arrearages on the common units. Notwithstanding the foregoing, the subordination period will end on the first business day after the Partnership has paid an aggregate amount of at least $2.025 per unit (150.0% of the MQD on an annualized basis) on the outstanding common and subordinated units and the Partnership has paid the related distribution on the incentive distribution rights, for any four-quarter period ending on or after March 31, 2015 and there are no outstanding arrearages on the common units. Our partnership agreement provides that our general partner will make a determination as to whether a distribution will be made, but our partnership agreement does not require us to pay distributions at any time or at any amount. Our partnership agreement authorizes us to issue an unlimited number of additional partnership interests for the consideration and on the terms and conditions determined by our general partner without the approval of the unitholders.
	Incentive Distribution Rights
	Our general partner owns all of the incentive distribution rights (“IDRs”). IDRs represent the right to receive an increasing percentage of quarterly distributions of available cash from operating surplus after the MQD and the target distribution levels (described below) have been achieved. Our general partner may transfer these rights separately from its general partner interest, subject to restrictions in our partnership agreement. Our general partner, as the IDR holder, will have the right, subsequent to the subordination period and subject to distributions exceeding the MQD by at least 150% for four consecutive quarters, to reset the target distribution levels and receive common units.
	Allocation of Net Income (Loss)
	Our partnership agreement contains provisions for the allocation of net income and loss to the unitholders and the general partner. For purposes of maintaining partner capital accounts, the partnership agreement generally specifies that items of income and loss shall be allocated among the partners in accordance with their respective percentage interest.
	Percentage Allocation of Available Cash from Operating Surplus
	The following table illustrates the percentage allocation of available cash from operating surplus between the unitholders and our general partner (as the holder of our IDRs) based on the specified target distribution levels. The amounts set forth under the column heading “Marginal Percentage Interest in Distributions” are the percentage interests of the IDR holder and the unitholders of any available cash from operating surplus we distribute up to and including the corresponding amount in the column “Total Quarterly Distribution Per Common Unit”. The percentage interests shown for our unitholders and our general partner for the MQD are also applicable to quarterly distribution amounts that are less than the MQD. The percentage interests set forth below assumes there are no arrearages on common units.
		Total Quarterly Distribution	Marginal Percentage
		Per Common Unit	Interest in Distributions
			Unitholders			General Partner (IDRs)
	Minimum quarterly distribution	$0.34		100	%		—
	First target distribution	Above $0.3375 up to $0.3881		100	%		—
	Second target distribution	Above $0.3881 up to $0.4219		85	%		15	%
	Third target distribution	Above $0.4219 up to $0.5063		75	%		25	%
	Thereafter	Above $0.5063		50	%		50	%
	Our partnership agreement sets forth the calculation to be used to determine the amount and priority of cash distributions that the common and subordinated unitholders and general partner will receive.
	On August 29, 2014, we paid a quarterly cash distribution of $0.03 per unit to all unitholders equal to the MQD, rounded-up, and prorated for the period from the closing date of the IPO to the end of the second quarter (June 23, 2014 through June 30, 2014).
	On November 6, 2014, we declared a quarterly cash distribution of $0.35 per unit to all unitholders of record on November 14, 2014.  The cash distribution is in excess of the MQD and is expected to be paid on November 25, 2014.
	Predecessor Members’ Deficit
	In May 2014, based upon the terms of the 2013 Reorganization, FELLC distributed to its members approximately 1,900 acres of surface land not needed for current or currently projected future operations and $0.1 million in cash. The carrying value of the distributed land was $12.2 million. Additionally, in connection with the acquisition of Seneca Rebuild LLC on April 1, 2014, a deemed distribution in the amount of $0.3 million was recorded to reflect the excess of the purchase price paid by FELLC over the carrying value of the net assets acquired (see Note 15).
	On June 23, 2014, in connection with the IPO, Foresight Reserves and a member of management each contributed their membership interests in FELLC to the Partnership in exchange for common and subordinated units of FELP (see Note 3).  As a result, the members’ deficit balance of $104.9 million at the time of the transfer was allocated, pro rata based on units outstanding, to common and subordinated unitholder capital accounts.
	Noncontrolling Interests
	Noncontrolling interests and net income attributable to noncontrolling interests result from the consolidation of variable interest entities for which the Partnership has no equity interests (see Note 16).

LongTerm_Debt_and_Capital_Leas

Long-Term Debt and Capital Lease Obligations	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Long-Term Debt and Capital Lease Obligations	'
	5. Long-Term Debt and Capital Lease Obligations
	Long-term debt and capital lease obligations consist of the following:
		September 30,			December 31,
		2014			2013
		(In Thousands)
	2021 Senior Notes	$	596,105		$	595,795
	Term Loan		235,737			444,602
	Revolving Credit Facility		342,500			259,000
	Interim longwall financing arrangement		—			31,616
	5.78% longwall financing arrangement		67,230			72,833
	5.555% longwall financing arrangement		61,875			72,187
	Capital lease obligations		33,738			43,180
	Total long-term debt and capital lease obligations		1,337,185			1,519,213
	Less: current portion		(34,471	)		(70,034	)
	Long-term debt and capital lease obligations	$	1,302,714		$	1,449,179
	Term Loan
	In June 2014, we used proceeds from the IPO to repay $210.0 million in principal outstanding under the Term Loan. This prepayment resulted in the write-off of $2.8 million in unamortized debt issuance costs and $1.9 million of unamortized debt discount. The prepayment of principal was applied to prospective scheduled quarterly principal payments as set forth in the credit agreement such that no further scheduled payments are due until the Term Loan matures on August 23, 2020.
	Revolving Credit Facility
	The Revolving Credit Facility has a total borrowing capacity of $500.0 million. At September 30, 2014, we had borrowings of $342.5 million outstanding under the Revolving Credit Facility and $7.1 million outstanding in letters of credit. There was $150.4 million of remaining capacity under the Revolving Credit Facility as of September 30, 2014 and the weighted-average effective interest rate on borrowings as of September 30, 2014 and December 31, 2013 was 3.5%.
	Interim Longwall Financing Arrangement
	In November 2013, FELLC entered into an interim longwall financing arrangement and master lease agreement with a lender to finance the installment payments required under a contract with a vendor for the purchase of a set of longwall shields and related parts and equipment. This interim longwall financing arrangement, as amended, allowed for borrowings up to the expected purchase price of $63.2 million. In May 2014, the interim longwall financing arrangement and master lease agreement were terminated with the repayment of the $61.3 million outstanding balance and $0.3 million in lender fees were recorded to loss on early extinguishment of debt for the early termination of the master lease agreement.

Coal_Derivative_Contracts

Coal Derivative Contracts	9 Months Ended
	Sep. 30, 2014
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'
Coal Derivative Contracts	'
	6. Coal Derivative Contracts
	The Partnership has commodity price risk for its coal sales as a result of changes in the market value of its coal. To minimize this risk, we enter into long-term, fixed price coal supply sales agreements and coal derivative contracts.
	As of September 30, 2014 and December 31, 2013, we had outstanding coal derivative contracts to fix the selling price on 4.2 million tons and 2.0 million tons, respectively. The coal derivative contracts are economic hedges to certain future unpriced (indexed) sales commitments and expected sales through 2017.  The coal derivative contracts are indexed to the Argus API 2 price index, the benchmark price for coal imported into northwest Europe. The coal derivative contracts are accounted for as freestanding derivatives and any gains or losses resulting from adjusting these contracts to fair value are recorded into earnings. We record the fair value of all positions with a given counterparty on a gross basis in the consolidated balance sheets (see Note 17).
	A summary of the unrealized and realized gains recorded on coal derivatives for the three and nine months ended September 30, 2014 and 2013 is as follows:
		Three Months Ended				Nine Months Ended
		September 30,		September 30,		September 30,		September 30,
		2014		2013		2014		2013
		(In Thousands)
	Unrealized gain on coal derivatives	$	16,001	$	1,200	$	33,711	$	1,428
	Realized gain on coal derivatives		2,989		—		7,708		452
	Gain on coal derivatives	$	18,990	$	1,200	$	41,419	$	1,880
	We received $1.0 million in proceeds during the nine months ended September 30, 2013 from the settlement of derivatives that were recorded as an investing activity in the condensed consolidated statement of cash flows because the derivative contracts were settled prior to the underlying sales contracts.

EquityBased_Compensation

Equity-Based Compensation	9 Months Ended
	Sep. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Equity-Based Compensation	'
	7. Equity-Based Compensation
	Long-Term Incentive Plan
	Upon the closing of the IPO, our general partner adopted a Long-Term Incentive Plan (“LTIP”), pursuant to which employees of the Partnership and directors, officers, and certain employees of our general partner and its affiliates (collectively, the “Participants”) are eligible to receive awards with respect to the Partnership’s common units. The LTIP allows the board of directors of our general partner, at its discretion, to grant unit options, unit appreciation rights, restricted units, phantom units, unit awards, other unit-based awards, distribution equivalent rights, performance awards and substitute awards to Participants. The LTIP is administered by the board of directors of our general partner. Vesting and forfeiture requirements are at the discretion of the board of directors of our general partner at the time of each grant. The LTIP authorized up to 7.0 million common units to be granted by the board of directors.
	Upon the closing of the IPO, pre-existing cash-based compensation liability awards, which vest ratably over a three-year period from the award date, will prospectively be settled in FELP units.  As a result, on June 23, 2014, $0.6 million was reclassified from accrued expenses and other current liabilities to partners’ capital in the condensed consolidated balance sheet for the award modification from cash to 0.1 million phantom units.  No compensation expense was recorded as a result of the modification of these awards.
	Subsequent to the IPO, 0.5 million phantom units were granted to employees under the LTIP, of which 0.1 million units were immediately vested upon the grant date. Also, 7,919 phantom units were granted to the independent directors, as defined by the NYSE, on the board of directors of our general partner. Upon the vesting date of phantom units, Participants will receive common units in the Partnership. These phantom units granted under the LTIP include tandem distribution equivalent rights (“DERs”) which provide for the right to accrue quarterly cash distributions in an amount equal to the cash distribution the Partnership makes to unitholders during the vesting period. These awards are subject to service-based vesting conditions and any accrued distributions will be forfeited if the related awards fail to vest according to the relevant service-based vesting conditions. DERs will be settled in cash upon vesting.
	The grants to employees under the LTIP were measured at their grant date fair value and the compensation expense is recognized ratably over the vesting period. The phantom units granted to the independent directors of the board of directors were initially recognized at the grant date fair value and will be remeasured at fair value over the vesting period. Total equity-based compensation costs of $1.1 million and $3.3 million was recognized for the three and nine months ended September 30, 2014. As of September 30, 2014, there was $10.1 million in total unrecognized compensation expense related to the non-vested phantom unit awards that are expected to vest which will be recognized over a weighted-average remaining service period of 2.5 years. As of September 30, 2014, the intrinsic value of the non-vested phantom unit awards expected to vest was $10.9 million.

Earnings_per_Limited_Partner_U

Earnings per Limited Partner Unit	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Earnings per Limited Partner Unit	'
	8. Earnings per Limited Partner Unit
	Limited partners’ interest in net income attributable to the Partnership and basic and diluted earnings per unit reflect net income attributable to the Partnership from the June 23, 2014 closing date of the IPO through September 30, 2014. We compute earnings per unit (“EPU”) using the two-class method for master limited partnerships as prescribed in ASC 260, Earnings Per Share. The two-class method requires that securities that meet the definition of a participating security be considered for inclusion in the computation of basic EPU. In addition to the common and subordinated units, we have also identified the general partner interest and IDRs as participating securities. Under the two-class method, EPU is calculated as if all of the earnings for the period were distributed under the terms of the partnership agreement, regardless of whether the general partner has discretion over the amount of distributions to be made in any particular period, whether those earnings would actually be distributed during a particular period from an economic or practical perspective, or whether the general partner has other legal or contractual limitations on its ability to pay distributions that would prevent it from distributing all of the earnings for a particular period.
	The Partnership’s net income is allocated to the limited partners, including the holders of the subordinated units, in accordance with their respective ownership percentages, after giving effect to any special income or expense allocations and incentive distributions paid to the general partner, if any. The partnership agreement contractually limits distributions to available cash as determined by our general partner; therefore, undistributed earnings of the Partnership are not allocated to the IDR holder. There were no allocations of earnings to participating securities during the periods presented below. Basic EPU is computed by dividing net earnings attributable to unitholders by the weighted-average number of units outstanding during each period. However, because our IPO was completed on June 23, 2014, the units outstanding from the IPO date are utilized for the 2014 periods presented.  Basic common units outstanding includes the 2,625,000 overallotment units offered to the underwriters, which were issued to Foresight Reserves and a member of management in July 2014, as of the IPO date. Diluted EPU reflects the potential dilution of common equivalent units that could occur if equity participation units are converted into common units.
	The following table illustrates the Partnership’s calculation of net income per common and subordinated unit for the periods indicated:
		Common Unitholders		Subordinated Unitholders		Total
	Three months ended September 30, 2014	(In Thousands, Except Per Unit Data)
	Numerator:
	Net income available to limited partner units	$	22,691	$	22,675	$	45,366
	Denominator:
	Weighted-average units to calculate basic EPU		64,786		64,739		129,525
	Less: effect of dilutive securities (1)		—		—		—
	Weighted-average units to calculate diluted EPU		64,786		64,739		129,525
	Basic net income per unit	$	0.35	$	0.35	$	0.35
	Diluted net income per unit	$	0.35	$	0.35	$	0.35
		Common Unitholders		Subordinated Unitholders		Total
	Nine months ended September 30, 2014	(In Thousands, Except Per Unit Data)
	Numerator:
	Net income subsequent to IPO (June 23, 2014 through	$	20,619	$	20,517	$	41,136
	September 30, 2014) available to limited partner units
	Denominator:
	Weighted-average units to calculate basic EPU		64,786		64,739		129,525
	Less: effect of dilutive securities (1)		—		—		—
	Weighted-average units to calculate diluted EPU		64,786		64,739		129,525
	Basic net income per unit	$	0.32	$	0.32	$	0.32
	Diluted net income per unit	$	0.32	$	0.32	$	0.32
	(1) -	Diluted EPU gives effect to all dilutive potential common units outstanding during the period using the treasury stock method. Diluted EPU excludes all dilutive potential units calculated under the treasury stock method if their effect is anti-dilutive. For the three and nine months ended September 30, 2014, approximately 0.7 million phantom units were anti-dilutive, and therefore excluded from the diluted EPU calculation.

Accounts_Receivable

Accounts Receivable	9 Months Ended
	Sep. 30, 2014
Accounts Receivable Net [Abstract]	'
Accounts Receivable	'
	9. Accounts Receivable
	Accounts receivable consists of the following:
		September 30,		December 31,
		2014		2013
		(In Thousands)
	Trade accounts receivable	$	87,311	$	54,084
	Other receivables		5,334		4,903
	Total accounts receivable	$	92,645	$	58,987

Inventories

Inventories	9 Months Ended
	Sep. 30, 2014
Inventory Disclosure [Abstract]	'
Inventories	'
	10. Inventories
	Inventories consist of the following:
		September 30,		December 31,
		2014		2013
		(In Thousands)
	Parts and supplies	$	32,598	$	30,155
	Raw coal		11,265		4,250
	Clean coal		54,624		36,885
	Total inventories	$	98,487	$	71,290

Property_Plant_Equipment_and_D

Property, Plant, Equipment and Development, Net	9 Months Ended
	Sep. 30, 2014
Property Plant And Equipment [Abstract]	'
Property, Plant, Equipment and Development, Net	'
	11. Property, Plant, Equipment and Development, Net
	Property, plant, equipment and development, net consist of the following:
		September 30,			December 31,
		2014			2013
		(In Thousands)
	Land, land rights and mineral rights	$	106,532		$	114,058
	Machinery and equipment		1,092,666			984,920
	Machinery and equipment under capital leases		70,500			70,500
	Buildings and structures		223,372			218,037
	Development costs		674,688			619,117
	Other		9,747			8,564
	Property, plant, equipment and development		2,177,505			2,015,196
	Less: accumulated depreciation, depletion and amortization		(729,780	)		(601,122	)
	Property, plant, equipment and development, net	$	1,447,725		$	1,414,074

Accrued_Expenses_and_Other_Cur

Accrued Expenses and Other Current Liabilities	9 Months Ended
	Sep. 30, 2014
Accrued Liabilities And Other Liabilities [Abstract]	'
Accrued Expenses and Other Current Liabilities	'
	12. Accrued Expenses and Other Current Liabilities
	Accrued expenses and other current liabilities consist of the following:
		September 30,		December 31,
		2014		2013
		(In Thousands)
	Employee compensation, benefits and payroll taxes	$	18,590	$	17,137
	Taxes other than income		4,204		4,270
	Royalties (non-affiliate)		3,779		2,999
	Liquidated damages (non-affiliate)		6,193		7,448
	Other		5,794		5,661
	Total accrued expenses and other current liabilities	$	38,560	$	37,515

SaleLeaseback_Financing_Arrang

Sale-Leaseback Financing Arrangements	9 Months Ended
	Sep. 30, 2014
Leases Capital [Abstract]	'
Sale-Leaseback Financing Arrangements	'
	13. Sale-Leaseback Financing Arrangements
	In 2009, Macoupin sold certain of its coal reserves and rail facilities to WPP, LLC (“WPP”), a subsidiary of Natural Resource Partners, LP (“NRP”), and leased them back. The gross proceeds from this transaction were $143.5 million and were used for capital expenditures. In 2012, Sugar Camp sold certain rail facilities to HOD, LLC (“HOD”), a subsidiary of NRP, and leased them back. The gross proceeds from this transaction were $50.0 million and were used for capital expenditures, to pay down debt and for general corporate purposes. NRP is an affiliated entity to the Partnership (see Note 15). In both transactions, because we had continuing involvement in the assets sold, the transactions were treated as sale-leaseback financing arrangements. In 2013, an agreement was reached between FELLC, Foresight Reserves and HOD that allows for the existing agreement with Sugar Camp to be amended in the future to include coal produced from Sugar Camp’s second longwall on what is expected to be materially consistent terms as the original agreement. Pursuant to such an amendment occurring, the consideration paid by HOD for including coal produced by Sugar Camp’s second longwall will be paid directly to Foresight Reserves. As of September 30, 2014, the outstanding principal balance on the Macoupin and Sugar Camp sale-leaseback financing arrangements was $143.5 million and $50.0 million, respectively.
	The implied effective interest rate as of September 30, 2014 on the Macoupin sale-leaseback financing arrangement and the Sugar Camp sale-leaseback financing arrangement was 14.2% and 14.0%, respectively. If there is a material change to the mine plans, the impact of a change in the effective interest rate to the consolidated statements of operations could be significant. Interest expense recorded on the Macoupin sale-leaseback was $5.2 million for the three months ended September 30, 2014 and 2013 and $14.8 million and $15.0 million for the nine months ended September 30, 2014 and 2013, respectively. Interest expense recorded on the Sugar Camp sale-leaseback was $1.4 million and $2.1 million for the three months ended September 30, 2014 and 2013, respectively, and $4.9 million and $5.5 million for the nine months ended September 30, 2014 and 2013, respectively. As of September 30, 2014 and December 31, 2013, interest totaling $9.2 million and $9.1 million, respectively, was accrued in the condensed consolidated balance sheets for the Sugar Camp and Macoupin sale-leaseback financing arrangements.

Asset_Retirement_Obligations

Asset Retirement Obligations	9 Months Ended
	Sep. 30, 2014
Asset Retirement Obligation Disclosure [Abstract]	'
Asset Retirement Obligations	'
	14. Asset Retirement Obligations
	The change in the carrying amount of asset retirement obligations was as follows for the nine months ended September 30, 2014:
		September 30,
		2014
		(In Thousands)
	Balance at January 1, 2014 (including current portion)	$	21,225
	Accretion expense		1,215
	Expenditures for reclamation activities		(772	)
	Balance at September 30, 2014 (including current portion)		21,668
	Less: current portion of asset retirement obligations		(809	)
	Noncurrent portion of asset retirement obligations	$	20,859

RelatedParty_Transactions

Related-Party Transactions	9 Months Ended
	Sep. 30, 2014
Related Party Transactions [Abstract]	'
Related-Party Transactions	'
	15. Related-Party Transactions
	The chairman of our general partner’s board of directors and the controlling member of Foresight Reserves, Chris Cline, directly and indirectly beneficially owns an interest in the general and limited partner interests of NRP. We routinely engage in transactions in the normal course of business with NRP and its subsidiaries and Foresight Reserves and its affiliates. These transactions include production royalties, transportation services, administrative arrangements, coal handling and storage services, supply agreements, service agreements, land leases and sale-leaseback financing arrangements (see Note 13, sale-leaseback financing arrangements are excluded from the tables below). We have also acquired mining equipment from Foresight Reserves and affiliated entities in the past.
	On August 1, 2013, FELLC entered into an equipment repair and rebuild agreement with Seneca Rebuild LLC (“Seneca Rebuild”), an affiliated entity owned indirectly by Chris Cline. The agreement called for Seneca Rebuild to be the primary provider of repair and rebuild services for mining machinery and equipment for our mines. Effective April 1, 2014, FELLC reached an agreement to acquire Seneca Rebuild. Because FELLC and Seneca Rebuild were under common control, the assets and liabilities of Seneca Rebuild were recorded by FELLC at carrying value on the acquisition date. Seneca Rebuild’s net assets on the acquisition date principally consisted of $3.4 million in plant, property and equipment and $0.5 million in inventory. The $0.3 million paid over the excess of the carrying value of the net assets of Seneca Rebuild on the acquisition date was recorded as a deemed distribution. Given the immateriality of this acquisition, the financial statements of Seneca Rebuild are reflected prospectively in the consolidated financial statements of the Partnership.
	Limited Partnership Agreement
	The Partnership’s general partner manages the Partnership’s operations and activities as specified in the partnership agreement. The general partner of the Partnership is managed by its board of directors. Foresight Reserves has the right to select the directors of the general partner. The members of the board of directors of the general partner are not elected by the unitholders and are not subject to reelection by the unitholders. The officers of the general partner manage the day-to-day affairs of the Partnership’s business. The partnership agreement provides that the Partnership will reimburse its general partner for all direct and indirect expenses incurred or payments made by the general partner on behalf of the Partnership. No amounts were incurred by the general partner or reimbursed under the partnership agreement from the IPO date to September 30, 2014.
	The following table presents the affiliate amounts included in our condensed consolidated balance sheets:
	Affiliated Company		Balance Sheet Location		September 30,				December 31,
					2014				2013
					(In Thousands)
	Foresight Reserves and affiliated entities		Due from affiliates		$	126			$	368
	NRP and affiliated entities		Due from affiliates			133				—
	Total				$	259			$	368
	Foresight Reserves and affiliated entities		Due to affiliates		$	7,594			$	4,521
	NRP and affiliated entities		Due to affiliates			8,071				5,051
	Total				$	15,665			$	9,572
	Foresight Reserves and affiliated entities		Prepaid royalties		$	36,190			$	37,644
	NRP and affiliated entities		Prepaid royalties			43,580				39,801
	Total				$	79,770			$	77,445
	A summary of expenses (income) incurred with affiliated entities is as follows for the three and nine months ended September 30, 2014 and 2013:
		Three Months Ended								Nine Months Ended
		September 30,				September 30,				September 30,			September 30,
		2014				2013				2014			2013
		(In Thousands)
	Royalty expense – NRP and affiliated entities(1)	$	11,755			$	14,051			$	37,779		$	37,520
	Royalty expense – Foresight Reserves and affiliated entities(1)	$	2,477			$	3,861			$	6,403		$	4,298
	Loadout services – NRP and affiliated entities(1)	$	2,175			$	2,763			$	7,609		$	7,537
	Terminal fees – Foresight Reserves and affiliated entities(2)	$	11,233			$	6,857			$	37,535		$	20,879
	Management and transportation usage fees – Foresight	$	—			$	(31	)		$	—		$	1,488
	Reserves and affiliated entities(3)
	Administrative fee income – Foresight	$	(60	)		$	(15	)		$	(196	)	$	(105	)
	Reserves and affiliated entities(4)
	Location in the condensed consolidated statements of operations:
	(1) – Cost of coal produced (excluding depreciation, depletion and amortization)
	(2) – Transportation
	(3) – Selling, general and administrative
	(4) – Other operating loss (income), net
	During the three and nine months ended September 30, 2014 and 2013, we paid an annual rental fee of $0.1 million to New River Royalty, LLC, a subsidiary of Foresight Reserves, under two land leases. We also purchased $5.8 million and $13.4 million in mining supplies from an affiliated joint venture under a supply agreement entered into in May 2013 during the three and nine months ended September 30, 2014, respectively, and $3.6 million and $6.3 million during the three and nine months ended September 30, 2013, respectively (see Note 16).

Variable_Interest_Entities_VIE

Variable Interest Entities (VIEs)	9 Months Ended
	Sep. 30, 2014
Variable Interest Entity Nonconsolidated Carrying Amount Assets And Liabilities [Abstract]	'
Variable Interest Entities (VIEs)	'
	16. Variable Interest Entities (VIEs)
	The consolidated financial statements include VIEs for which the Partnership or its subsidiary is the primary beneficiary. Among those VIEs consolidated by the Partnership and its subsidiaries are Mach Mining, LLC; M-Class Mining, LLC; MaRyan Mining LLC; Patton Mining LLC; Viking Mining LLC, Coal Field Construction Company LLC; Coal Field Repair Services LLC and LD Labor Company LLC (prior to the 2013 Reorganization date discussed below) (collectively, the “Contractor VIEs”). Coal Field Repair Services LLC provides contract labor for Seneca Rebuild, acquired on April 1, 2014 (see Note 15), under a cost-plus arrangement. Each of the Contractor VIEs holds a contract to provide one or more of the following services to a Partnership subsidiary: contract mining, processing and loading services, or construction and maintenance services. Each of the Contractor VIEs generally receives a nominal per ton fee ($0.01 to $0.02 per ton) above its cost of operations as compensation for services performed. All of these entities were determined not to have sufficient equity at risk and are therefore VIEs. The Partnership was determined to be the primary beneficiary of each of these entities given it controls these entities under a contractual cost-plus arrangement. During the three and nine months ended September 30, 2014, in aggregate, the Contractor VIEs earned income of $0.1 million and $0.3 million, respectively, under the contractual arrangements with the Partnership which was recorded as net income attributable to noncontrolling interests in the condensed consolidated statements of operations. During the three and nine months ended September 30, 2013, in aggregate, the Contractor VIEs earned income of $0.1 million and $0.2 million, respectively, under the contractual arrangements with the Partnership.
	On August 23, 2013, FELLC effected the 2013 Reorganization pursuant to which certain transportation assets were distributed to its members. Among the assets distributed were Adena Resources LLC (“Adena”), a subsidiary that provides water and other miscellaneous rights to the mines and Hillsboro’s coal loadout facility, including the land on which the facility is situated (collectively, the “Loadout”).
	Adena has various water rights contracts that are used to provide water to the Partnership’s mines. Concurrent with the distribution of Adena to FELLC members, we entered into a water resources agreement between the Partnership’s mines and Adena providing for water resources to be available at each of the mines. As compensation for furnishing water to the mines, we pay Adena the actual cost (including capital expenditures) incurred by Adena plus an annual fee of $10,000. Adena is determined not to have sufficient equity at risk and is therefore a VIE. The Partnership is determined to be the primary beneficiary of Adena given it controls this entity under a contractual cost-plus arrangement. During the three and nine months ended September 30, 2014, Adena incurred a loss of $0.1 million and $0.4 million, respectively, which was recorded as net income attributable to noncontrolling interests in the condensed consolidated statements of operations. During the three and nine months ended September 30, 2013, Adena incurred a loss of $0.1 million.
	Subsequent to the 2013 Reorganization, Foresight Reserves placed the Loadout into a newly created subsidiary, Hillsboro Transport, LLC (“Hillsboro Transport”). A throughput agreement was entered into between Hillsboro and Hillsboro Transport for Hillsboro Transport to operate the Loadout. As compensation for operating and maintaining the Loadout, Hillsboro pays $0.99 per ton for every ton of coal loaded through the Loadout, subject to a minimum quarterly payment of $1.3 million, which began in the first quarter of 2014. Hillsboro Transport was determined not to have sufficient equity at risk as a result of the throughput agreement’s guaranteed minimum quarterly payment and is therefore a VIE. Hillsboro was determined to be the primary beneficiary of this entity as it implicitly controls Hillsboro Transport given the related-party relationship between Hillsboro and Hillsboro Transport and the fact that the sole assets held by Hillsboro Transport are unique to Hillsboro’s operations. During the three and nine months ended September 30, 2014, Hillsboro Transport earned $0.8 million and $2.9 million, respectively, in net income under this arrangement, which is presented in net income attributable to noncontrolling interests in the condensed consolidated statements of operations. During the three and nine months ended September 30, 2013, Hillsboro Transport earned net income of $0.8 million.
	The liabilities recognized as a result of consolidating the VIEs do not necessarily represent additional claims on the general assets of the Partnership outside of the VIEs; rather, they represent claims against the specific assets of the consolidated VIEs. Conversely, assets recognized as a result of consolidating these VIEs do not necessarily represent additional assets that could be used to satisfy claims against the Partnership’s general assets. There are no restrictions on the VIE assets that are reported in the Partnership’s general assets. The total consolidated VIE assets and liabilities reflected in the Partnership’s condensed consolidated balance sheets are as follows:
		September 30,		December 31,
		2014		2013
		(In Thousands)
	Assets:
	Current assets	$	3,043	$	4,386
	Long-term assets		1,691		2,141
	Total assets	$	4,734	$	6,527
	Liabilities:
	Current liabilities	$	14,869	$	5,310
	Long-term liabilities		167		157
	Total liabilities	$	15,036	$	5,467
	In May 2013, an affiliate owned by Chris Cline and a third-party supplier of mining supplies formed a joint venture whose purpose is the manufacture and sale of supplies primarily for use by the Partnership in the conduct of its mining operations. The agreement obligates the Partnership’s coal mines to purchase at least 90% of their aggregate annual requirements for certain mining supplies from the supplier parties, subject to exceptions as set forth in the agreement. The initial term of the amended agreement is five years and expires in April 2018. The supplies sold under this arrangement result in an agreed-upon fixed profit percentage for the joint venture. This joint venture was determined to be a VIE given that the equity holders do not have the obligation to absorb the expected losses or the right to receive the expected residual returns of the joint venture as a result of the Partnership effectively guaranteeing a fixed-profit percentage on the supplies it purchases from the joint venture. We are not the primary beneficiary of this joint venture and, therefore, do not consolidate the joint venture, given that the power over the joint venture is conveyed through the board of directors of the joint venture and no party controls the board of directors.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	17. Fair Value of Financial Instruments
	The table below sets forth, by level, the Partnership’s net financial assets and liabilities for which fair value is measured on a recurring basis:
		Fair Value at September 30, 2014
		Total			Level 1		Level 2			Level 3
		(In Thousands)
	Coal derivative contracts	$	37,170		$	—	$	37,170		$	—
	Total	$	37,170		$	—	$	37,170		$	—
		Fair Value at December 31, 2013
		Total			Level 1		Level 2			Level 3
		(In Thousands)
	Coal derivative contracts	$	2,020		$	—	$	2,020		$	—
	Liability Award		(11,700	)		—		—			(11,700	)
	Total	$	(9,680	)	$	—	$	2,020		$	(11,700	)
	The Partnership’s coal derivative contracts are valued based on direct broker quotes and corroborated with API 2 market pricing data. The liability award represents a phantom equity award (“Liability Award”) to a retired executive for which the value was determined based on the fair value, as defined in the agreement, of Foresight Reserves as of the employee’s retirement date and was adjusted for distributions made to Foresight Reserves’ members. This Liability Award fully vested in 2010 and was granted principally for services performed to develop the Partnership’s longwall mines. Prior to March 31, 2014, the Liability Award was Level 3 in the fair value hierarchy given Foresight Reserves was a private company; therefore, there was no liquid market to determine the fair value of Foresight Reserves’ equity. The fair value of the Liability Award was determined using a discounted cash flow model and corroborated with recent equity transactions at Foresight Reserves. Effective March 31, 2014, the Liability Award amount was negotiated between the Partnership and the employee to be $12.4 million; therefore, the value of this liability was contracted and therefore no longer a Level 3 liability. As of September 30, 2014, $0.4 million of the unpaid balance is recorded in accrued expenses and other current liabilities for required payments over the next year, and the remaining $3.9 million is recorded in other long-term liabilities, which will be paid out ratably over the next ten years. The note payable to the retired executive currently bears interest at 3.45%.
	The classification and amount of the Partnership’s financial instruments measured at fair value on a recurring basis, which are presented on a gross basis in the condensed consolidated balance sheets as of September 30, 2014 and December 31, 2013, are as follows:
		Fair Value at September 30, 2014
		Current – Coal Derivative Assets			Long-Term –  Coal Derivative Assets		Accrued Expenses			Other Long-Term Liabilities
		(In Thousands)
	Coal derivative contracts	$	19,942		$	17,228	$	—		$	—
	Total	$	19,942		$	17,228	$	—		$	—
		Fair Value at December 31, 2013
		Current – Coal Derivative Assets			Long-Term –  Coal Derivative Assets		Accrued Expenses			Other Long-Term Liabilities
		(In Thousands)
	Coal derivative contracts	$	1,976		$	912	$	(531	)	$	(337	)
	Liability Award		—			—		(11,700	)		—
	Total	$	1,976		$	912	$	(12,231	)	$	(337	)
	The following is a reconciliation of the beginning and ending balances for assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the nine months ended September 30, 2014 and 2013:
		Liability Award
		(In Thousands)
	Balance at January 1, 2014	$	11,700
	Recorded fair value losses (gains):
	Included in earnings		690
	Purchases, issuances and settlements		(12,390	)
	Balance at September 30, 2014	$	—
	Balance at January 1, 2013	$	—
	Recorded fair value losses (gains):
	Included in earnings		716
	Capitalized into development costs		(217	)
	Purchases, issuances and settlements		11,240
	Balance at September 30, 2013	$	11,739
	During the nine months ended September 30, 2014 and 2013, there were no assets or liabilities that were transferred between Level 1 and Level 2.
	Long-Term Debt
	The fair value of long-term debt as of September 30, 2014 and December 31, 2013 was $1,240.9 million and $1,509.2 million, respectively. The fair value of long-term debt was calculated based on the amount of future cash flows associated with each debt instrument discounted at the Partnership’s current estimated credit-adjusted borrowing rate for similar debt instruments with comparable terms. This is considered a Level 3 fair value measurement.

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Contingencies	'
	18. Contingencies
	In April 2013, the Illinois Environmental Protection Agency (“IEPA”) issued Sugar Camp two violation notices regarding exceedances in effluent discharge from the mine site and improper dilution of high chloride effluent. Sugar Camp believes it is now in compliance with its permit. In March 2014, the IEPA issued Sugar Camp a violation notice regarding non-compliant effluent discharge from the mining operation. Sugar Camp has reclaimed a temporary holding pond that may have contributed to the violation and is currently in compliance with its permit. On July 8, 2014, Sugar Camp entered into a Compliance Commitment Agreement with the IEPA (“July CCA”) identifying a schedule of actions expected to resolve the March 2014 violation.   The IEPA has notified Sugar Camp that the compliance commitment agreements entered into with respect to the two April 2013 violation notices were superseded by the July CCA and are no longer of any force or effect.  Violation of the terms of the July CCA could result in the assessment of fines or penalties or a suspension of mining at the affected operations until a final solution is obtained.
	In January 2014, the IEPA issued Sugar Camp a violation notice regarding construction of an underground injection well without issuance of an appropriate permit (“January Notice”). Sugar Camp has ceased all drilling activities at the site and is working with the IEPA to finalize its permit application, which has been in process since May 2013. The IEPA has determined not to enter into a compliance commitment agreement with respect to the January Notice.  However, there can be no assurances that the January Notice will not be referred to the Office of the Attorney General for further processing.  While Sugar Camp believes this referral may result in the assessment of a penalty of an amount yet to be determined, there can be no assurances that an acceptable agreement will be reached. Failure to reach a satisfactory agreement with the Office of the Attorney General with respect to the January Notice could result in the assessment of fines or penalties or a suspension of mining at the affected operations until a final solution is obtained.
	Sugar Camp is working with the IEPA to implement a sustainable solution for the future disposal of water at the mine in compliance with its permits. Including actions required under the July CCA, Sugar Camp expects to incur capital expenditures of approximately $30.5 million, $25.5 million of which has been expended through September 30, 2014.
	In November 2012, six citizens filed requests for administrative review of Revision No. 1 to Permit No. 399 for the Hillsboro mine. Revision No. 1 allowed for conversion of the currently permitted coal refuse disposal facility from a non-impounding to an impounding structure. Shortly after the filing of Revision No. 1, one citizen withdrew his request. Following a hearing on both the Illinois Department of Natural Resources’ (IDNR) and Hillsboro’s motions to dismiss, the hearing officer dismissed the claims of two of the remaining five petitioners and also limited some of the issues remaining for administrative review. In June 2014, two of the remaining three petitioners voluntarily dismissed their requests. Hillsboro has filed a motion for summary judgment on the remaining petitioner’s issue.
	In June 2014, two citizens requested an administrative review of Permit No. 424 for the Hillsboro mine.  Permit No. 424 allows for the construction and operation of a second refuse disposal area at the mine.  In response to Hillsboro’s motions to dismiss, the hearing officer dismissed one of the petitioners and limited some of the appealable issues for the remaining petitioner.  Currently, the remaining petitioner and Hillsboro are conducting discovery on the final petitioner’s remaining issue. It is too early in the administrative review process to assess the Partnership’s likelihood of prevailing.
	FELLC acquired the Shay No. 1 Mine at Macoupin (“Shay Mine”) in 2009. Prior to the acquisition of the mine, in 2003, ExxonMobil Coal USA, Inc. (“Exxon”), the prior owner of the Shay Mine, enrolled the mine in the IEPA’s Site Remediation Program (“SRP”) to address some concerns regarding groundwater contamination from the refuse areas. Under the SRP, Exxon and Macoupin collected and quantified requested data. In 2011, Macoupin proposed, and the IEPA accepted, a compliance commitment agreement (“CCA”) with remediation steps designed to respond to the groundwater contamination concerns. Further, in May 2013, Macoupin submitted a corrective action plan (“CAP”) with groundwater modeling to the IEPA to address the long-term compliance and corrective measures planned for the cleanup of groundwater contamination issues. In June 2013, the IEPA referred the CCA to the Illinois Attorney General’s Office for enforcement on the basis that the compliance period for the CCA extended for too long of a period for the IEPA to monitor. We believe that the CAP for the groundwater issues will be finalized and implemented through a consent decree with the Illinois Attorney General’s Office at some point in the future. As of September 30, 2014, the Partnership had accrued $12.0 million for this matter as an asset retirement obligation, as it relates to ongoing mining operations at Macoupin. However, there can be no assurance that the ultimate costs will not exceed this amount.
	In addition, in 2013, the IDNR renewed a permit for the refuse disposal area. An environmental group has submitted a Request for Administrative Review of this permit renewal and the legal proceeding is ongoing. While the Partnership believes the IDNR decisions on the issuance of the permit for slurry disposal and renewal for existing refuse disposal area were proper, there can be no guarantee that the permit and the revisions to permits will not be vacated or substantially modified, which could result in additional costs or cessation of some or all operations at the mine.
	We are also party to various other litigation matters, in most cases involving ordinary and routine claims incidental to our business. We cannot reasonably estimate the ultimate legal and financial liability with respect to all pending litigation matters. However, we believe, based on our examination of such matters, that the ultimate liability will not have a material adverse effect on our financial position, results of operations or cash flows. As of September 30, 2014, we have $1.2 million accrued, in aggregate, for various litigation matters.
	Performance Bonds
	We had outstanding surety bonds with third parties of approximately $53.0 million as of September 30, 2014 to secure reclamation and other performance commitments. The Partnership is not required to post collateral for these bonds.

New_Accounting_Standards_Polic

New Accounting Standards (Policies)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
New Accounting Standards Issued and Not Yet Adopted	'
	New Accounting Standards Issued and Not Yet Adopted
	In April 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. ASU 2014-08 changes the requirements for reporting discontinued operations by updating the criteria for determining discontinued operations and modifies the disclosure requirements of both discontinued operations and certain other disposals not defined as discontinued operations. ASU 2014-08 is effective for annual and interim periods beginning after December 15, 2014 and we do not expect it will have a material impact on our consolidated financial statements.
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, to clarify the principles used to recognize revenue. The guidance is effective for annual and interim periods beginning after December 15, 2016. Early adoption is not permitted. We will evaluate the effects, if any, the adoption of this guidance will have on our consolidated financial statements.
	In August 2014, the FASB issued ASU 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which requires management of a company to evaluate whether there is substantial doubt about the company’s ability to continue as a going concern. This ASU is effective for the annual reporting period ending after December 15, 2016, with early adoption permitted. This standard is not currently expected to have a material effect on the Partnership's financial statement disclosures, though the ultimate impact will be dependent on the Partnership's financial condition and expected operating outlook.

Partners_Capital_Tables

Partners' Capital (Tables)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Schedule of Percentage Allocations of Available Cash from Operating Surplus	'
	The following table illustrates the percentage allocation of available cash from operating surplus between the unitholders and our general partner (as the holder of our IDRs) based on the specified target distribution levels. The amounts set forth under the column heading “Marginal Percentage Interest in Distributions” are the percentage interests of the IDR holder and the unitholders of any available cash from operating surplus we distribute up to and including the corresponding amount in the column “Total Quarterly Distribution Per Common Unit”. The percentage interests shown for our unitholders and our general partner for the MQD are also applicable to quarterly distribution amounts that are less than the MQD. The percentage interests set forth below assumes there are no arrearages on common units.
		Total Quarterly Distribution	Marginal Percentage
		Per Common Unit	Interest in Distributions
			Unitholders			General Partner (IDRs)
	Minimum quarterly distribution	$0.34		100	%		—
	First target distribution	Above $0.3375 up to $0.3881		100	%		—
	Second target distribution	Above $0.3881 up to $0.4219		85	%		15	%
	Third target distribution	Above $0.4219 up to $0.5063		75	%		25	%
	Thereafter	Above $0.5063		50	%		50	%

LongTerm_Debt_and_Capital_Leas1

Long-Term Debt and Capital Lease Obligations (Tables)	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
Schedule of Long-Term Debt and Capital Lease Obligations	'
	Long-term debt and capital lease obligations consist of the following:
		September 30,			December 31,
		2014			2013
		(In Thousands)
	2021 Senior Notes	$	596,105		$	595,795
	Term Loan		235,737			444,602
	Revolving Credit Facility		342,500			259,000
	Interim longwall financing arrangement		—			31,616
	5.78% longwall financing arrangement		67,230			72,833
	5.555% longwall financing arrangement		61,875			72,187
	Capital lease obligations		33,738			43,180
	Total long-term debt and capital lease obligations		1,337,185			1,519,213
	Less: current portion		(34,471	)		(70,034	)
	Long-term debt and capital lease obligations	$	1,302,714		$	1,449,179

Coal_Derivative_Contracts_Tabl

Coal Derivative Contracts (Tables)	9 Months Ended
	Sep. 30, 2014
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'
Summary of (Gain)/Loss on Coal Derivatives	'
	A summary of the unrealized and realized gains recorded on coal derivatives for the three and nine months ended September 30, 2014 and 2013 is as follows:
		Three Months Ended				Nine Months Ended
		September 30,		September 30,		September 30,		September 30,
		2014		2013		2014		2013
		(In Thousands)
	Unrealized gain on coal derivatives	$	16,001	$	1,200	$	33,711	$	1,428
	Realized gain on coal derivatives		2,989		—		7,708		452
	Gain on coal derivatives	$	18,990	$	1,200	$	41,419	$	1,880

Earnings_per_Limited_Partner_U1

Earnings per Limited Partner Unit (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Summary of Partnership's Calculation of Net Income per Common and Subordinated Unit	'
	The following table illustrates the Partnership’s calculation of net income per common and subordinated unit for the periods indicated:
		Common Unitholders		Subordinated Unitholders		Total
	Three months ended September 30, 2014	(In Thousands, Except Per Unit Data)
	Numerator:
	Net income available to limited partner units	$	22,691	$	22,675	$	45,366
	Denominator:
	Weighted-average units to calculate basic EPU		64,786		64,739		129,525
	Less: effect of dilutive securities (1)		—		—		—
	Weighted-average units to calculate diluted EPU		64,786		64,739		129,525
	Basic net income per unit	$	0.35	$	0.35	$	0.35
	Diluted net income per unit	$	0.35	$	0.35	$	0.35
		Common Unitholders		Subordinated Unitholders		Total
	Nine months ended September 30, 2014	(In Thousands, Except Per Unit Data)
	Numerator:
	Net income subsequent to IPO (June 23, 2014 through	$	20,619	$	20,517	$	41,136
	September 30, 2014) available to limited partner units
	Denominator:
	Weighted-average units to calculate basic EPU		64,786		64,739		129,525
	Less: effect of dilutive securities (1)		—		—		—
	Weighted-average units to calculate diluted EPU		64,786		64,739		129,525
	Basic net income per unit	$	0.32	$	0.32	$	0.32
	Diluted net income per unit	$	0.32	$	0.32	$	0.32
	(1) -	Diluted EPU gives effect to all dilutive potential common units outstanding during the period using the treasury stock method. Diluted EPU excludes all dilutive potential units calculated under the treasury stock method if their effect is anti-dilutive. For the three and nine months ended September 30, 2014, approximately 0.7 million phantom units were anti-dilutive, and therefore excluded from the diluted EPU calculation.

Accounts_Receivable_Tables

Accounts Receivable (Tables)	9 Months Ended
	Sep. 30, 2014
Accounts Receivable Net [Abstract]	'
Schedule of Accounts Receivable	'
	Accounts receivable consists of the following:
		September 30,		December 31,
		2014		2013
		(In Thousands)
	Trade accounts receivable	$	87,311	$	54,084
	Other receivables		5,334		4,903
	Total accounts receivable	$	92,645	$	58,987

Inventories_Tables

Inventories (Tables)	9 Months Ended
	Sep. 30, 2014
Inventory Disclosure [Abstract]	'
Schedule of Inventories	'
	Inventories consist of the following:
		September 30,		December 31,
		2014		2013
		(In Thousands)
	Parts and supplies	$	32,598	$	30,155
	Raw coal		11,265		4,250
	Clean coal		54,624		36,885
	Total inventories	$	98,487	$	71,290

Property_Plant_Equipment_and_D1

Property, Plant, Equipment and Development, Net (Tables)	9 Months Ended
	Sep. 30, 2014
Property Plant And Equipment [Abstract]	'
Schedule of Property, Plant, Equipment and Development, Net	'
	Property, plant, equipment and development, net consist of the following:
		September 30,			December 31,
		2014			2013
		(In Thousands)
	Land, land rights and mineral rights	$	106,532		$	114,058
	Machinery and equipment		1,092,666			984,920
	Machinery and equipment under capital leases		70,500			70,500
	Buildings and structures		223,372			218,037
	Development costs		674,688			619,117
	Other		9,747			8,564
	Property, plant, equipment and development		2,177,505			2,015,196
	Less: accumulated depreciation, depletion and amortization		(729,780	)		(601,122	)
	Property, plant, equipment and development, net	$	1,447,725		$	1,414,074

Accrued_Expenses_and_Other_Cur1

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2014
Accrued Liabilities And Other Liabilities [Abstract]	'
Schedule of Accrued Expenses and Other Current Liabilities	'
	Accrued expenses and other current liabilities consist of the following:
		September 30,		December 31,
		2014		2013
		(In Thousands)
	Employee compensation, benefits and payroll taxes	$	18,590	$	17,137
	Taxes other than income		4,204		4,270
	Royalties (non-affiliate)		3,779		2,999
	Liquidated damages (non-affiliate)		6,193		7,448
	Other		5,794		5,661
	Total accrued expenses and other current liabilities	$	38,560	$	37,515

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	9 Months Ended
	Sep. 30, 2014
Asset Retirement Obligation Disclosure [Abstract]	'
Changes in Carrying Amount of Asset Retirement Obligations	'
	The change in the carrying amount of asset retirement obligations was as follows for the nine months ended September 30, 2014:
		September 30,
		2014
		(In Thousands)
	Balance at January 1, 2014 (including current portion)	$	21,225
	Accretion expense		1,215
	Expenditures for reclamation activities		(772	)
	Balance at September 30, 2014 (including current portion)		21,668
	Less: current portion of asset retirement obligations		(809	)
	Noncurrent portion of asset retirement obligations	$	20,859

RelatedParty_Transactions_Tabl

Related-Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2014
Related Party Transactions [Abstract]	'
Summary of Affiliate Amounts Included in Condensed Consolidated Balance Sheets	'
	The following table presents the affiliate amounts included in our condensed consolidated balance sheets:
	Affiliated Company		Balance Sheet Location		September 30,				December 31,
					2014				2013
					(In Thousands)
	Foresight Reserves and affiliated entities		Due from affiliates		$	126			$	368
	NRP and affiliated entities		Due from affiliates			133				—
	Total				$	259			$	368
	Foresight Reserves and affiliated entities		Due to affiliates		$	7,594			$	4,521
	NRP and affiliated entities		Due to affiliates			8,071				5,051
	Total				$	15,665			$	9,572
	Foresight Reserves and affiliated entities		Prepaid royalties		$	36,190			$	37,644
	NRP and affiliated entities		Prepaid royalties			43,580				39,801
	Total				$	79,770			$	77,445
Summary of Expenses (Income) Incurred With Affiliated Entities	'
	A summary of expenses (income) incurred with affiliated entities is as follows for the three and nine months ended September 30, 2014 and 2013:
		Three Months Ended								Nine Months Ended
		September 30,				September 30,				September 30,			September 30,
		2014				2013				2014			2013
		(In Thousands)
	Royalty expense – NRP and affiliated entities(1)	$	11,755			$	14,051			$	37,779		$	37,520
	Royalty expense – Foresight Reserves and affiliated entities(1)	$	2,477			$	3,861			$	6,403		$	4,298
	Loadout services – NRP and affiliated entities(1)	$	2,175			$	2,763			$	7,609		$	7,537
	Terminal fees – Foresight Reserves and affiliated entities(2)	$	11,233			$	6,857			$	37,535		$	20,879
	Management and transportation usage fees – Foresight	$	—			$	(31	)		$	—		$	1,488
	Reserves and affiliated entities(3)
	Administrative fee income – Foresight	$	(60	)		$	(15	)		$	(196	)	$	(105	)
	Reserves and affiliated entities(4)
	Location in the condensed consolidated statements of operations:
	(1) – Cost of coal produced (excluding depreciation, depletion and amortization)
	(2) – Transportation
	(3) – Selling, general and administrative
	(4) – Other operating loss (income), net

Variable_Interest_Entities_VIE1

Variable Interest Entities (VIEs) (Tables)	9 Months Ended
	Sep. 30, 2014
Variable Interest Entity Nonconsolidated Carrying Amount Assets And Liabilities [Abstract]	'
Summary of Consolidated VIE Assets and Liabilities	'
	The liabilities recognized as a result of consolidating the VIEs do not necessarily represent additional claims on the general assets of the Partnership outside of the VIEs; rather, they represent claims against the specific assets of the consolidated VIEs. Conversely, assets recognized as a result of consolidating these VIEs do not necessarily represent additional assets that could be used to satisfy claims against the Partnership’s general assets. There are no restrictions on the VIE assets that are reported in the Partnership’s general assets. The total consolidated VIE assets and liabilities reflected in the Partnership’s condensed consolidated balance sheets are as follows:
		September 30,		December 31,
		2014		2013
		(In Thousands)
	Assets:
	Current assets	$	3,043	$	4,386
	Long-term assets		1,691		2,141
	Total assets	$	4,734	$	6,527
	Liabilities:
	Current liabilities	$	14,869	$	5,310
	Long-term liabilities		167		157
	Total liabilities	$	15,036	$	5,467

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value of Net Financial Assets and Liabilities Measured on Recurring Basis	'
	The table below sets forth, by level, the Partnership’s net financial assets and liabilities for which fair value is measured on a recurring basis:
		Fair Value at September 30, 2014
		Total			Level 1		Level 2			Level 3
		(In Thousands)
	Coal derivative contracts	$	37,170		$	—	$	37,170		$	—
	Total	$	37,170		$	—	$	37,170		$	—
		Fair Value at December 31, 2013
		Total			Level 1		Level 2			Level 3
		(In Thousands)
	Coal derivative contracts	$	2,020		$	—	$	2,020		$	—
	Liability Award		(11,700	)		—		—			(11,700	)
	Total	$	(9,680	)	$	—	$	2,020		$	(11,700	)
Fair Value of Gross Financial Assets and Liabilities Measured on a Recurring Basis	'
	The classification and amount of the Partnership’s financial instruments measured at fair value on a recurring basis, which are presented on a gross basis in the condensed consolidated balance sheets as of September 30, 2014 and December 31, 2013, are as follows:
		Fair Value at September 30, 2014
		Current – Coal Derivative Assets			Long-Term –  Coal Derivative Assets		Accrued Expenses			Other Long-Term Liabilities
		(In Thousands)
	Coal derivative contracts	$	19,942		$	17,228	$	—		$	—
	Total	$	19,942		$	17,228	$	—		$	—
		Fair Value at December 31, 2013
		Current – Coal Derivative Assets			Long-Term –  Coal Derivative Assets		Accrued Expenses			Other Long-Term Liabilities
		(In Thousands)
	Coal derivative contracts	$	1,976		$	912	$	(531	)	$	(337	)
	Liability Award		—			—		(11,700	)		—
	Total	$	1,976		$	912	$	(12,231	)	$	(337	)
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation Table Text Block	'
	The following is a reconciliation of the beginning and ending balances for assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the nine months ended September 30, 2014 and 2013:
		Liability Award
		(In Thousands)
	Balance at January 1, 2014	$	11,700
	Recorded fair value losses (gains):
	Included in earnings		690
	Purchases, issuances and settlements		(12,390	)
	Balance at September 30, 2014	$	—
	Balance at January 1, 2013	$	—
	Recorded fair value losses (gains):
	Included in earnings		716
	Capitalized into development costs		(217	)
	Purchases, issuances and settlements		11,240
	Balance at September 30, 2013	$	11,739

Organization_Nature_of_Busines1

Organization, Nature of Business and Basis of Presentation - Additional Information (Details) (Foresight Energy LLC)	9 Months Ended
	Sep. 30, 2014
Foresight Reserves, LP	'
Schedule Of Organization Nature Of Business And Basis Of Presentation [Line Items]	'
Ownership percentage prior to 6/23/2014	99.33%
Member of Management	'
Schedule Of Organization Nature Of Business And Basis Of Presentation [Line Items]	'
Ownership percentage prior to 6/23/2014	0.67%

Initial_Public_Offering_Additi

Initial Public Offering - Additional Information (Details) (USD $)	0 Months Ended	9 Months Ended		0 Months Ended			1 Months Ended	0 Months Ended
	Jun. 23, 2014	Sep. 30, 2014	Jul. 31, 2014	Jun. 23, 2014	Jun. 23, 2014	Jun. 23, 2014	Jul. 31, 2014	Jun. 23, 2014	Jun. 23, 2014
				Common Units	Subordinated Units	Term Loan	Shares Held by Public	Foresight Energy GP LLC	Foresight Energy GP LLC
								Foresight Reserves, LP	Foresight Reserves Management
Initial Public Offering [Line Items]	'	'	'	'	'	'	'	'	'
Number of common units issued to Foresight Reserves and a member of management	'	'	'	44,613,895	64,738,895	'	'	'	'
Partnership interest owned	'	'	'	'	'	'	13.50%	99.33%	0.67%
Maximum IDR holder marginal percentage interest in distributions	50.00%	'	'	'	'	'	'	'	'
IDR quarterly distribution per unit distribution threshold	$0.39	'	'	'	'	'	'	'	'
Partnership units issued to public	17,500,000	'	'	'	'	'	'	'	'
Partnership units issue price per unit	$20	'	'	'	'	'	'	'	'
Proceeds from issuance of common units (net of underwriters' discount)	$329,900,000	$329,875,000	'	'	'	'	'	'	'
Underwriters discount	20,100,000	'	'	'	'	'	'	'	'
Proceeds from sale of common units used to repay term loan	'	'	'	'	'	210,000,000	'	'	'
Proceeds from sale of common units used to pay reserve and members	115,000,000	'	'	'	'	'	'	'	'
Additional offering costs, partners capital	'	$7,100,000	'	'	'	'	'	'	'
Over allotment units issued	'	'	2,625,000	'	'	'	'	'	'

Partners_Capital_Addtional_Inf

Partners' Capital - Addtional Information (Details) (USD $)	0 Months Ended		1 Months Ended	3 Months Ended	9 Months Ended		0 Months Ended
	Jun. 30, 2014	Apr. 02, 2014	31-May-14	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Nov. 25, 2014
			acre				Subsequent Event
Capital Unit [Line Items]	'	'	'	'	'	'	'
Minimum quarterly distribution per unit	'	'	'	'	$0.34	'	'
Conversion of common units, description	'	'	'	'	'Subordinated units will convert to common units, on a one-for-one basis, on the first business day after the Partnership has paid the MQD for each of three consecutive, non-overlapping four-quarter periods ending on or after March 31, 2017 and there are no outstanding arrearages on the common units. Notwithstanding the foregoing, the subordination period will end on the first business day after the Partnership has paid an aggregate amount of at least $2.025 per unit (150.0% of the MQD on an annualized basis) on the outstanding common and subordinated units and the Partnership has paid the related distribution on the incentive distribution rights, for any four-quarter period ending on or after March 31, 2015 and there are no outstanding arrearages on the common units.	'	'
Percentage paid of MQD required for conversion of subordinated units to common units	'	'	'	'	150.00%	'	'
Aggregate per unit annual distribution amount, for conversion of subordinated units to common units	'	'	'	$2.02	$2.02	'	'
Cash distribution paid	'	'	'	$0.03	'	'	'
Cash distribution payment date	'	'	'	'	29-Aug-14	'	'
Cash distribution declared	'	'	'	$0.03	$0.03	'	$0.35
Cash distribution declaration date	'	'	'	'	6-Nov-14	'	'
Cash distribution record date	'	'	'	'	14-Nov-14	'	'
Members deficit balance allocated, pro rata base	$104,900,000	'	'	'	'	'	'
Surface land distributed to members	'	'	1,900	'	'	'	'
Distribution paid in cash	'	'	100,000	'	'	'	'
Carrying value of the land distributed to members	'	'	12,200,000	'	12,187,000	61,990,000	'
Deemed distribution	'	$300,000	'	'	'	'	'

Partners_Capital_Schedule_of_P

Partners' Capital - Schedule of Percentage Allocations of Available Cash from Operating Surplus (Details) (USD $)	9 Months Ended
	Sep. 30, 2014
Minimum Quarterly Distribution	'
Distribution Made To Limited Partner [Line Items]	'
Total Quarterly Distribution Per Common Unit, maximum	$0.34
Percentage Distributed To Unitholders	100.00%
First Target Distribution	'
Distribution Made To Limited Partner [Line Items]	'
Total Quarterly Distribution Per Common Unit, minimum	$0.34
Total Quarterly Distribution Per Common Unit, maximum	$0.39
Percentage Distributed To Unitholders	100.00%
Second Target Distribution	'
Distribution Made To Limited Partner [Line Items]	'
Total Quarterly Distribution Per Common Unit, minimum	$0.39
Total Quarterly Distribution Per Common Unit, maximum	$0.42
Percentage Distributed To Unitholders	85.00%
Percentage Distributed to General Partner (IDRs)	15.00%
Third Target Distribution	'
Distribution Made To Limited Partner [Line Items]	'
Total Quarterly Distribution Per Common Unit, minimum	$0.42
Total Quarterly Distribution Per Common Unit, maximum	$0.51
Percentage Distributed To Unitholders	75.00%
Percentage Distributed to General Partner (IDRs)	25.00%
Thereafter	'
Distribution Made To Limited Partner [Line Items]	'
Total Quarterly Distribution Per Common Unit, maximum	$0.51
Percentage Distributed To Unitholders	50.00%
Percentage Distributed to General Partner (IDRs)	50.00%

LongTerm_Debt_and_Capital_Leas2

Long-Term Debt and Capital Lease Obligations (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Capital lease obligations	$33,738	$43,180
Total long-term debt and capital lease obligations	1,337,185	1,519,213
Less: current portion	-34,471	-70,034
Long-term debt and capital lease obligations	1,302,714	1,449,179
2021 Senior Notes	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	596,105	595,795
Term Loan	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	235,737	444,602
Interim longwall financing arrangement	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	'	31,616
5.78% longwall financing arrangement	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	67,230	72,833
5.555% Longwall financing arrangement	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	61,875	72,187
Revolving Credit Facility	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	$342,500	$259,000

LongTerm_Debt_and_Capital_Leas3

Long-Term Debt and Capital Lease Obligations - Additional Information (Details) (USD $)	3 Months Ended	9 Months Ended				0 Months Ended	9 Months Ended	1 Months Ended
	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Dec. 31, 2013	Jun. 30, 2014	Sep. 30, 2014	31-May-14	Nov. 30, 2013
				Revolving Credit Facility	Revolving Credit Facility	Term Loan	Term Loan	Interim longwall financing arrangement	Interim longwall financing arrangement
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'	'
Repayment of long-term debt	'	'	'	'	'	$210,000,000	'	$61,300,000	'
Unamortized debt issuance costs	'	'	'	'	'	2,800,000	'	'	'
Unamortized debt discount balance	'	'	'	'	'	1,900,000	'	'	'
Maturity date of borrowings	'	'	'	'	'	'	23-Aug-20	'	'
State maximum borrowings under facility	'	'	'	500,000,000	'	'	'	'	63,200,000
Amount of borrowings outstanding under revolving credit facility	'	'	'	342,500,000	'	'	'	'	'
Outstanding letters of credit	'	'	'	7,100,000	'	'	'	'	'
Remaining borrowing capacity under revolving credit facility	'	'	'	150,400,000	'	'	'	'	'
Effective weighted-average interest rate on borrowings under revolving credit facility	'	'	'	3.50%	3.50%	'	'	'	'
Amount of fees recorded in loss on early extinguishment of debt	($77,755,000)	($4,979,000)	($77,755,000)	'	'	'	'	$300,000	'

Coal_Derivative_Contracts_Addi

Coal Derivative Contracts - Additional Information (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2014	Dec. 31, 2013
		T	T
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'	'	'
Outstanding coal derivative contracts	'	4,200,000	2,000,000
Proceeds from settlement of derivatives	$1	'	'

Coal_Derivative_Contracts_Summ

Coal Derivative Contracts - Summary of (Gain)/Loss on Coal Derivatives (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Unrealized gain on coal derivatives	'	'	$33,711	$1,428
Gain on coal derivatives	18,990	1,200	41,419	1,880
Coal Derivative Contracts	'	'	'	'
Derivative Instruments Gain Loss [Line Items]	'	'	'	'
Unrealized gain on coal derivatives	16,001	1,200	33,711	1,428
Realized gain on coal derivatives	2,989	'	7,708	452
Gain on coal derivatives	$18,990	$1,200	$41,419	$1,880

EquityBased_Compensation_Addit

Equity-Based Compensation - Additional Information (Details) (USD $)	3 Months Ended	9 Months Ended			0 Months Ended	9 Months Ended			9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2013	Jun. 23, 2014	Jun. 23, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014
				Award Modification	Phantom Share Units (PSUs)	Phantom Share Units (PSUs)	Phantom Share Units (PSUs)	Long-Term Incentive Plan	Long-Term Incentive Plan
							Independent Director		Phantom Share Units (PSUs)
									IPO
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'	'	'	'	'	'	'	'
Aggregate number of common units authorized	'	'	'	'	'	'	'	7,000,000	'
Equity-based compensation award, vesting period	'	'3 years	'	'	'	'	'	'	'
Accrued expenses and other current liabilities	$38,560,000	$38,560,000	$37,515,000	$600,000	'	'	'	'	'
Number of units reclassified	'	'	'	'	100,000	'	'	'	'
Compensation expense	'	0	'	'	'	'	'	'	'
Number of units granted	'	'	'	'	'	'	7,919	'	500,000
Number of units vested	'	'	'	'	'	100,000	'	'	'
Equity-based compensation cost	1,100,000	3,257,000	'	'	'	'	'	'	'
Unrecognized share based compensation expense	'	'	'	'	'	10,100,000	'	'	'
Weighted average period for recognition of expense	'	'	'	'	'	'2 years 6 months	'	'	'
Intrinsic value of non-vested grants	'	'	'	'	'	$10,900,000	'	'	'

Earnings_per_Limited_Partner_U2

Earnings per Limited Partner Unit (Details) (Underwriters overallotment)	Jul. 18, 2014
Underwriters overallotment	'
Incentive Distribution Made To Managing Member Or General Partner [Line Items]	'
Shares, Issued	2,625,000

Earnings_per_Limited_Partner_U3

Earnings per Limited Partner Unit - Summary of Partnership's Calculation of Net Income per Common and Subordinated Unit (Details) (USD $)	3 Months Ended			9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 2013
Distribution Made To Limited Partner [Line Items]	'		'	'		'
Net income available to limited partner units	$45,366		($58,637)	$106,144		($15,456)
Weighted-average units to calculate basic EPU	129,525		'	129,525		'
Less: effect of dilutive securities	0	[1]	'	0	[1]	'
Weighted-average units to calculate diluted EPU	129,525		'	129,525		'
Basic net income per unit	$0.35		'	$0.32		'
Diluted net income per unit	$0.35		'	$0.32		'
Net income subsequent to initial public offering attributable to limited partner units (June 23, 2014 through September 30, 2014)	'		'	41,136		'
Common Unitholders	'		'	'		'
Distribution Made To Limited Partner [Line Items]	'		'	'		'
Net income available to limited partner units	22,691		'	'		'
Weighted-average units to calculate basic EPU	64,786		'	64,786		'
Less: effect of dilutive securities	0	[1]	'	0	[1]	'
Weighted-average units to calculate diluted EPU	64,786		'	64,786		'
Basic net income per unit	$0.35		'	$0.32		'
Diluted net income per unit	$0.35		'	$0.32		'
Net income subsequent to initial public offering attributable to limited partner units (June 23, 2014 through September 30, 2014)	'		'	20,619		'
Subordinated Units	'		'	'		'
Distribution Made To Limited Partner [Line Items]	'		'	'		'
Net income available to limited partner units	22,675		'	'		'
Weighted-average units to calculate basic EPU	64,739		'	64,739		'
Less: effect of dilutive securities	0	[1]	'	0	[1]	'
Weighted-average units to calculate diluted EPU	64,739		'	64,739		'
Basic net income per unit	$0.35		'	$0.32		'
Diluted net income per unit	$0.35		'	$0.32		'
Net income subsequent to initial public offering attributable to limited partner units (June 23, 2014 through September 30, 2014)	'		'	$20,517		'
[1]	Diluted EPU gives effect to all dilutive potential common units outstanding during the period using the treasury stock method. Diluted EPU excludes all dilutive potential units calculated under the treasury stock method if their effect is anti-dilutive. For the three and nine months ended September 30, 2014, approximately 0.7 million phantom units were anti-dilutive, and therefore excluded from the diluted EPU calculation.

Earnings_per_Limited_Partner_U4

Earnings per Limited Partner Unit - Summary of Partnership's Calculation of Net Income per Common and Subordinated Unit (Parenthetical) (Details) (Phantom Share Units (PSUs))	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2014
Phantom Share Units (PSUs)	'	'
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of earnings per share, amount	0.7	0.7

Accounts_Receivable_Schedule_o

Accounts Receivable - Schedule of Accounts Receivable (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts Receivable Net [Abstract]	'	'
Trade accounts receivable	$87,311	$54,084
Other receivables	5,334	4,903
Total accounts receivable	$92,645	$58,987

Inventories_Schedule_of_Invent

Inventories - Schedule of Inventories (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory [Line Items]	'	'
Parts and supplies	$32,598	$30,155
Inventories	98,487	71,290
Raw coal	'	'
Inventory [Line Items]	'	'
Coal	11,265	4,250
Clean coal	'	'
Inventory [Line Items]	'	'
Coal	$54,624	$36,885

Property_Plant_Equipment_and_D2

Property, Plant, Equipment and Development, Net (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property Plant And Equipment [Abstract]	'	'
Land, land rights and mineral rights	$106,532	$114,058
Machinery and equipment	1,092,666	984,920
Machinery and equipment under capital leases	70,500	70,500
Buildings and structures	223,372	218,037
Development costs	674,688	619,117
Other	9,747	8,564
Property, plant, equipment and development	2,177,505	2,015,196
Less: accumulated depreciation, depletion and amortization	-729,780	-601,122
Property, plant, equipment and development, net	$1,447,725	$1,414,074

Accrued_Expenses_and_Other_Cur2

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accrued Liabilities And Other Liabilities [Abstract]	'	'
Employee compensation, benefits and payroll taxes	$18,590	$17,137
Taxes other than income	4,204	4,270
Royalties (non-affiliate)	3,779	2,999
Liquidated damages (non-affiliate)	6,193	7,448
Other	5,794	5,661
Total accrued expenses and other current liabilities	$38,560	$37,515

SaleLeaseback_Financing_Arrang1

Sale-Leaseback Financing Arrangements - Additional Information (Details) (USD $)

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2009

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2012

Macoupin

Macoupin

Macoupin

Macoupin

Macoupin

Sugar Camp

Sugar Camp

Sugar Camp

Sugar Camp

Sugar Camp

Sale Leaseback Transaction [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Sale-leaseback transaction, description

'

'

'

'

'In 2009, Macoupin sold certain of its coal reserves and rail facilities to WPP, LLC (bWPPb), a subsidiary of Natural Resource Partners, LP (bNRPb), and leased them back. The gross proceeds from this transaction were $143.5 million and were used for capital expenditures.

'

'

'

'

'In 2012, Sugar Camp sold certain rail facilities to HOD, LLC (bHODb), a subsidiary of NRP, and leased them back. The gross proceeds from this transaction were $50.0 million and were used for capital expenditures, to pay down debt and for general corporate purposes.

'

'

Proceeds from sale-leaseback financing arrangement

'

'

'

'

'

'

$143,500,000

'

'

'

'

$50,000,000

Sale-leaseback financing arrangements

193,434,000

193,434,000

143,500,000

'

143,500,000

'

'

50,000,000

'

50,000,000

'

'

Sale-leaseback transaction, imputed interest rate

'

'

'

'

14.20%

'

'

'

'

14.00%

'

'

Sale-lease back transaction, interest expense

'

'

5,200,000

5,200,000

14,800,000

15,000,000

'

1,400,000

2,100,000

4,900,000

5,500,000

'

Sale-lease back transaction, accrued interest expense

$16,979,000

$27,645,000

'

$9,100,000

'

$9,100,000

'

$9,200,000

'

$9,200,000

'

'

Asset_Retirement_Obligations_C

Asset Retirement Obligations - Changes in Carrying Amount of Asset Retirement Obligations (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Asset Retirement Obligation Disclosure [Abstract]	'	'	'	'	'
Beginning balance	'	'	$21,225	'	'
Accretion expense	405	382	1,215	1,145	'
Expenditures for reclamation activities	'	'	-772	'	'
Ending balance	21,668	'	21,668	'	'
Less: current portion of asset retirement obligations	-809	'	-809	'	'
Noncurrent portion of asset retirement obligations	$20,859	'	$20,859	'	$20,416

RelatedParty_Transactions_Addi

Related-Party Transactions - Additional Information (Details) (USD $)	0 Months Ended	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Apr. 02, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Related Party Transaction [Line Items]	'	'	'	'	'
Plant, property and equipment, value	$3.40	'	'	'	'
Inventory, value	0.5	'	'	'	'
Amount paid excess of carrying value of net assets acquired	0.3	'	'	'	'
Purchase of mining supplies from affiliates	'	5.8	3.6	13.4	6.3
New River Royalty, LLC	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'
Rental fee	'	$0.10	$0.10	$0.10	$0.10
Number of land leases	'	2	'	2	'

RelatedParty_Transactions_Summ

Related-Party Transactions - Summary of Affiliate Amounts Included in Condensed Consolidated Balance Sheets (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Related Party Transaction [Line Items]	'	'
Due from affiliates	$259	$368
Due to affiliates	15,665	9,572
Prepaid royalties	12,010	6,330
Affiliates	'	'
Related Party Transaction [Line Items]	'	'
Due from affiliates	259	368
Due to affiliates	15,665	9,572
Prepaid royalties	79,770	77,445
Foresight Reserves and Affiliated Entities | Affiliates	'	'
Related Party Transaction [Line Items]	'	'
Due from affiliates	126	368
Due to affiliates	7,594	4,521
Prepaid royalties	36,190	37,644
NRP and Affiliated Entities | Affiliates	'	'
Related Party Transaction [Line Items]	'	'
Due from affiliates	133	'
Due to affiliates	8,071	5,051
Prepaid royalties	$43,580	$39,801

RelatedParty_Transactions_Summ1

Related-Party Transactions - Summary of Expenses (Income) Incurred With Affiliated Entities (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
NRP and Affiliated Entities	'		'		'		'
Related Party Transaction [Line Items]	'		'		'		'
Royalty expense	$11,755	[1]	$14,051	[1]	$37,779	[1]	$37,520	[1]
Loadout services	2,175	[1]	2,763	[1]	7,609	[1]	7,537	[1]
Foresight Reserves and Affiliated Entities	'		'		'		'
Related Party Transaction [Line Items]	'		'		'		'
Royalty expense	2,477	[1]	3,861	[1]	6,403	[1]	4,298	[1]
Terminal fees	11,233	[2]	6,857	[2]	37,535	[2]	20,879	[2]
Management and transportation usage fees	'		-31	[3]	'		1,488	[3]
Administrative fee income	($60)	[4]	($15)	[4]	($196)	[4]	($105)	[4]
[1]	Cost of coal produced (excluding depreciation, depletion and amortization)
[2]	Transportation
[3]	Selling, general and administrative
[4]	Other operating loss (income), net

Variable_Interest_Entities_VIE2

Variable Interest Entities (VIEs) - Additional Information (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Variable Interest Entity [Line Items]	'	'	'	'
Net income attributable to noncontrolling interests	$789,000	$804,000	$2,772,000	$1,010,000
Contractor VIEs	'	'	'	'
Variable Interest Entity [Line Items]	'	'	'	'
Net income attributable to noncontrolling interests	100,000	100,000	300,000	200,000
Minimum fee received per ton of coal mined or processed	'	'	0.01	'
Maximum fee paid per ton of coal mined or processed	'	'	0.02	'
Variable Interest Entity, Primary Beneficiary | Hillsboro Transport	'	'	'	'
Variable Interest Entity [Line Items]	'	'	'	'
Net income attributable to noncontrolling interests	800,000	800,000	2,900,000	800,000
Compensation for operating and maintaining loadout	'	'	0.99	'
Minimum quarterly payment	1,300,000	'	1,300,000	'
Variable Interest Entity, Primary Beneficiary | Adena Resources L L C	'	'	'	'
Variable Interest Entity [Line Items]	'	'	'	'
Net income attributable to noncontrolling interests	100,000	100,000	400,000	100,000
Compensation for furnishing water	'	'	$10,000	'
VIEs which the Partnership is not the Primary Beneficiary	'	'	'	'
Variable Interest Entity [Line Items]	'	'	'	'
Percentage of annual mining supply requirements purchased	'	'	90.00%	'
Initial term of agreement as amended	'	'	'5 years	'
Amended agreement term expiration date	'	'	'2018-04	'

Variable_Interest_Entities_VIE3

Variable Interest Entities (VIEs) - Summary of Consolidated VIE Assets and Liabilities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets	'	'
Current assets	$282,442	$186,096
Total assets	1,846,483	1,710,171
Liabilities:	'	'
Current liabilities	175,751	194,921
Total liabilities	1,696,634	1,858,287
Variable Interest Entity, Primary Beneficiary	'	'
Assets	'	'
Current assets	3,043	4,386
Long-term assets	1,691	2,141
Total assets	4,734	6,527
Liabilities:	'	'
Current liabilities	14,869	5,310
Long-term liabilities	167	157
Total liabilities	$15,036	$5,467

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Fair Value of Net Financial Assets and Liabilities (Details) (Fair Value, Measurements, Recurring, USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Total	$37,170	($9,680)
Fair Value, Level 2	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Total	37,170	2,020
Fair Value, Level 3	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Total	'	-11,700
Coal Derivative Contracts	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Coal derivative contracts	37,170	2,020
Coal Derivative Contracts | Fair Value, Level 2	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Coal derivative contracts	37,170	2,020
Liability Award	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Liability Award	'	-11,700
Liability Award | Fair Value, Level 3	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Liability Award	'	($11,700)

Fair_Value_Measures_and_Disclo

Fair Value Measures and Disclosures - Additional Information (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2014
				Accrued Expenses and Other Current Liabilities	Other Noncurrent Liabilities	Phantom Share Units (PSUs)	Liability Award
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'	'	'	'	'	'
Liability award that was contracted and removed from Level III measurement	'	'	'	'	'	$12,400,000	'
Other notes payable	'	'	'	400,000	3,900,000	'	'
Interest rate on other notes payable	'	'	'	'	'	'	3.45%
Assets or liabilities transferred between level 1 and level 2	0	'	0	'	'	'	'
Fair value of Long-Term Debt (Level III)	$1,240,900,000	$1,509,200,000	'	'	'	'	'

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - Fair Value of Gross Financial Assets and Liabilities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Current b Coal Derivative Assets	$19,942	$1,976
Long-Term b Coal Derivative Assets	17,228	912
Other Long-Term Liabilities	-3,876	-337
Other Long-Term Liabilities	3,876	337
Fair Value, Measurements, Recurring	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Current b Coal Derivative Assets	19,942	1,976
Long-Term b Coal Derivative Assets	17,228	912
Accrued Expenses	0	-12,231
Other Long-Term Liabilities	0	-337
Other Long-Term Liabilities	0	337
Fair Value, Measurements, Recurring | Coal Derivative Contracts	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Current b Coal Derivative Assets	19,942	1,976
Long-Term b Coal Derivative Assets	17,228	912
Accrued Expenses	0	-531
Other Long-Term Liabilities	0	-337
Other Long-Term Liabilities	0	337
Fair Value, Measurements, Recurring | Liability Award	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Accrued Expenses	'	-11,700
Other Long-Term Liabilities	'	0
Other Long-Term Liabilities	'	$0

Fair_Value_Measures_and_Disclo1

Fair Value Measures and Disclosures - Fair Value Measurement of Reconciliation of Beginning and Ending Balances for Assets and Liabilities (Details) (Fair Value, Measurements, Recurring, Liability Award, USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Fair Value, Measurements, Recurring | Liability Award	'	'
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]	'	'
Liability balance, beginning	$11,700	$0
Recorded fair value losses (gains):	'	'
Included in earnings	690	716
Capitalized into development costs	'	-217
Purchases, issuances and settlements	-12,390	11,240
Liability balance, ending	$0	$11,739

Contingencies_Additional_Infor

Contingencies - Additional Information (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014
			Surety Bond	Shay Mine	Sugar Camp
Loss Contingencies [Line Items]	'	'	'	'	'
Expected Capital expenditures under Sugar Camp compliance commitment agreement	'	'	'	'	$30,500,000
Actuals spent on capital expenditures to comply with the Sugar Camp compliance commitment agreement	'	'	'	'	25,500,000
Asset retirement obligations	21,668,000	21,225,000	'	12,000,000	'
Accrued litigation expense	1,200,000	'	'	'	'
Outstanding performance bonds	'	'	$53,000,000	'	'