Westmoreland Resource Partners (WMLPQ) 10-K 6 Mar 15 2014 FY Annual report Financial data

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Mar. 03, 2015	Jun. 30, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	Westmoreland Resource Partners, LP
Entity Central Index Key	1412347
Current Fiscal Year End Date	-19
Entity Filer Category	Smaller Reporting Company
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		5,711,636
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$8,112,648

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts payable and accrued expenses:
Asset retirement obligations	$7,783	$5,996
Successor [Member]
Current assets:
Cash	5,921	0
Receivables:
Trade	22,710
Other	116
Receivables, Net, Current	22,826
Inventory	14,013
Other current assets	1,317
Total current assets	44,077
Property, plant and equipment:
Property, Plant and Equipment, Gross	205,744
Less accumulated depreciation, depletion and amortization	0
Net property, plant and equipment	205,744
Advanced coal royalties	9,153
Restricted investments and bond collateral	10,621
Intangible assets, net of accumulated amortization of $0 and $2.1 million in December 31, 2014 and 2013, respectively	31,000
Deferred financing costs, net	6,993
Total Assets	307,588
Current liabilities:
Current installments of long-term debt	6
Accounts payable and accrued expenses:
Trade	19,135
Production taxes	1,033
Accrued compensation	1,531
Asset retirement obligations	7,783
Other current liabilities	4,007
Total current liabilities	33,495
Long-term debt, less current installments	175,029
Deferred revenue	0
Asset retirement obligations, less current portion	23,902
Warrants	1,981
Other liabilities	160
Total liabilities	234,567
Partners' capital (deficit):
Limited partners (5,505,087 and 1,740,589 units outstanding as of December 31, 2014 and 2013, respectively)	39,549
General partner (35,291 units outstanding as of December 31, 2014 and 2013)	33,472
Total Westmoreland Resource Partners, LP capital (deficit)	73,021
Noncontrolling interest	0
Total partners’ capital (deficit)	73,021
Total liabilities and partners’ capital (deficit)	307,588
Successor [Member] | Land and Mineral Rights [Member]
Property, plant and equipment:
Property, Plant and Equipment, Gross	71,715
Successor [Member] | Property, Plant and Equipment [Member]
Property, plant and equipment:
Property, Plant and Equipment, Gross	134,029
Predecessor [Member]
Current assets:
Cash	0	3,089
Receivables:
Trade		25,850
Other		4
Receivables, Net, Current		25,854
Inventory		13,840
Other current assets		1,733
Total current assets		44,516
Property, plant and equipment:
Property, Plant and Equipment, Gross		321,553
Less accumulated depreciation, depletion and amortization		-177,127
Net property, plant and equipment		144,426
Advanced coal royalties		11,404
Restricted investments and bond collateral		15,177
Intangible assets, net of accumulated amortization of $0 and $2.1 million in December 31, 2014 and 2013, respectively		1,188
Deferred financing costs, net		7,644
Total Assets		224,355
Current liabilities:
Current installments of long-term debt		7,901
Accounts payable and accrued expenses:
Trade		23,932
Production taxes		1,293
Accrued compensation		3,389
Asset retirement obligations		5,996
Other current liabilities		3,457
Total current liabilities		45,968
Long-term debt, less current installments		155,375
Deferred revenue		3,578
Asset retirement obligations, less current portion		25,658
Warrants		4,599
Other liabilities		175
Total liabilities		235,353
Partners' capital (deficit):
Limited partners (5,505,087 and 1,740,589 units outstanding as of December 31, 2014 and 2013, respectively)		-13,460
General partner (35,291 units outstanding as of December 31, 2014 and 2013)		-2,507
Total Westmoreland Resource Partners, LP capital (deficit)		-15,967
Noncontrolling interest		4,969
Total partners’ capital (deficit)	-34,492	-10,998
Total liabilities and partners’ capital (deficit)		224,355
Predecessor [Member] | Land and Mineral Rights [Member]
Property, plant and equipment:
Property, Plant and Equipment, Gross		110,667
Predecessor [Member] | Property, Plant and Equipment [Member]
Property, plant and equipment:
Property, Plant and Equipment, Gross		$210,886

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parentheticals) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Successor [Member]
Accumulated Amortization	$0
Limited partner capital account, units outstanding	5,505,087
General partner capital account, units outstanding	35,291
Predecessor [Member]
Accumulated Amortization		$2,100
Limited partner capital account, units outstanding		1,740,589
General partner capital account, units outstanding		35,291

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	0 Months Ended		12 Months Ended
	Dec. 31, 2014		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Successor [Member]
Costs and expenses:
Restructuring and impairment charges	$2,783,000	[1]
Total cost and expenses	2,783,000	[1]
Operating (loss) income	-2,783,000	[1]
Other (expense) income:
Interest expense	0	[1]
Interest income	0	[1]
(Loss) gain on debt extinguishment	-1,623,000	[1]
Change in fair value of warrants	0	[1]
Total other expenses	-1,623,000	[1]
Net loss	-4,406,000	[1]
Less net loss (income) attributable to noncontrolling interest	0	[1]
Net loss attributable to WMLP unitholders	-4,406,000	[1]
Less net loss allocated to general partner	-28,000	[1]
Net loss allocated to limited partners	-4,378,000	[1]
Net loss per limited partner unit:
Basic (dollars per share)	($0.72)
Diluted (dollars per share)	($0.72)
Weighted average number of limited partner units outstanding:
Basic (shares)	5,671,644
Diluted (shares)	5,671,644
Limited partners:
General partner (dollars per share)	$0
Successor [Member] | Common Units [Member]
Limited partners:
Distributions paid per unit, limited partners (dollars per share)	$0
Successor [Member] | Subordinated Units [Member]
Limited partners:
Distributions paid per unit, limited partners (dollars per share)	$0
Predecessor [Member]
Revenues:
Coal revenues			295,662,000	336,201,000	364,928,000
Royalty revenues			284,000	8,000	1,496,000
Non-coal revenues			26,317,000	10,558,000	7,103,000
Total Revenues			322,263,000	346,767,000	373,527,000
Costs and expenses:
Cost of coal revenues			258,575,000	290,427,000	312,467,000
Cost of non-coal revenues			1,700,000	1,619,000	1,195,000
Depreciation, depletion and amortization			39,315,000	48,081,000	51,170,000
Selling and administrative			20,510,000	17,297,000	15,629,000
(Gain) loss on sales of assets			-218,000	-6,488,000	-8,021,000
Restructuring and impairment charges			75,000	1,761,000	15,650,000
Total cost and expenses			319,957,000	352,697,000	388,090,000
Operating (loss) income			2,306,000	-5,930,000	-14,563,000
Other (expense) income:
Interest expense			-27,787,000	-20,246,000	-11,500,000
Interest income			4,000	4,000	10,000
(Loss) gain on debt extinguishment			500,000	-808,000	0
Change in fair value of warrants			822,000	3,280,000	0
Total other expenses			-26,461,000	-17,770,000	-11,490,000
Net loss			-24,155,000	-23,700,000	-26,053,000
Less net loss (income) attributable to noncontrolling interest			1,270,000	-1,225,000	-755,000
Net loss attributable to WMLP unitholders			-22,885,000	-24,925,000	-26,808,000
Less net loss allocated to general partner			-429,000	-497,000	-535,000
Net loss allocated to limited partners			($22,456,000)	($24,428,000)	($26,273,000)
Net loss per limited partner unit:
Basic (dollars per share)			($10.92)	($12.84)	($15.24)
Diluted (dollars per share)			($10.92)	($12.84)	($15.24)
Weighted average number of limited partner units outstanding:
Basic (shares)			2,063,983	1,898,040	1,725,996
Diluted (shares)			2,063,983	1,898,040	1,725,996
Limited partners:
General partner (dollars per share)			$0	$0	$12.90
Predecessor [Member] | Common Units [Member]
Limited partners:
Distributions paid per unit, limited partners (dollars per share)			$0	$0	$18.15
Predecessor [Member] | Subordinated Units [Member]
Limited partners:
Distributions paid per unit, limited partners (dollars per share)			$0	$0	$7.65
[1]	See Note 3.

Consolidated_Statements_of_Par

Consolidated Statements of Partners' Capital (Deficit) (USD $)	Predecessor [Member]	Successor [Member]		Common Units [Member]	Common Units [Member]	Subordinated [Member]	Subordinated [Member]	Subordinated [Member]	Limited Partners [Member]	Limited Partners [Member]	General Partner [Member]	General Partner [Member]	Noncontrolling Interest [Member]	Noncontrolling Interest [Member]	Noncontrolling Interest [Member]
				Predecessor [Member]	Successor [Member]		Predecessor [Member]	Successor [Member]	Predecessor [Member]	Successor [Member]	Predecessor [Member]	Successor [Member]		Predecessor [Member]	Successor [Member]
Balance at Dec. 31, 2011	$59,117,000			$121,911,000			($64,751,000)		$57,160,000		($1,032,000)			$2,989,000
Balance (units) at Dec. 31, 2011				868,312			856,698		1,725,010		35,170
Net (loss) income	-26,053,000			-13,237,000			-13,036,000		-26,273,000		-535,000			755,000
Partner contributions	12,000										12,000
Partners’ contributions (units)											121
Partner distributions	-22,777,000			-15,772,000			-6,550,000		-22,322,000		-455,000			0
Equity-based compensation	1,262,000			1,262,000			0		1,262,000		0
Issuance of units to LTIP participants	-234,000			-234,000					-234,000
Issuance of units to LTIP participants (units)				5,922					5,922
Balance at Dec. 31, 2012	11,327,000			93,930,000			-84,337,000		9,593,000		-2,010,000			3,744,000
Balance (units) at Dec. 31, 2012				874,234			856,698		1,730,932		35,291
Net (loss) income	-23,700,000			-12,374,000			-12,054,000		-24,428,000		-497,000			1,225,000
Equity-based compensation	1,441,000			1,441,000			0		1,441,000		0
Issuance of units to LTIP participants	-66,000			-66,000					-66,000
Issuance of units to LTIP participants (units)				9,657					9,657
Balance at Dec. 31, 2013	-10,998,000			82,931,000			-96,391,000		-13,460,000		-2,507,000			4,969,000
Balance (units) at Dec. 31, 2013				883,891			856,698		1,740,589		35,291
Net (loss) income	-24,155,000			-12,053,000			-10,403,000		-22,456,000		-429,000			-1,270,000
Equity-based compensation	4,559,000			4,559,000			0		4,559,000		0
Issuance of units to LTIP participants	-773,000			-773,000					-773,000
Issuance of units to LTIP participants (units)				108,696					108,696
Redemption of noncontrolling interest	-3,125,000			302,000			261,000		563,000		11,000			-3,699,000
Balance at Dec. 31, 2014	-34,492,000			74,966,000			-106,533,000		-31,567,000		-2,925,000			0	0
Balance (units) at Dec. 31, 2014				992,587			856,698		1,849,285		35,291
Balance at Dec. 30, 2014		73,021,000			39,549,000			0		39,549,000		33,472,000
Balance (units) at Dec. 30, 2014					5,505,087			856,698		6,361,785		35,291
Net (loss) income		-4,406,000	[1]		-4,378,000	0				-4,378,000		-28,000	0
Purchase accounting adjustment		78,767,000			-64,191,000			106,533,000		42,342,000		36,425,000
Kemmerer coal reserve contribution		33,152,000			33,152,000					33,152,000
Kemmerer coal reserve contribution (units)					4,512,500					4,512,500
Balance at Dec. 31, 2014															$0
[1]	See Note 3.

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion and amortization	$39,315,000	$48,081,000	$51,170,000
Accretion of asset retirement obligations	2,337,000	2,293,000
Amortization of intangible assets and liabilities, net	227,000	254,000	242,000
Non-cash interest expense	4,100,000	3,200,000	2,200,000
Successor [Member]
Cash flows from operating activities:
Net loss				-4,406,000	[1]
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion and amortization				0
Accretion of asset retirement obligations				0
Amortization of intangible assets and liabilities, net				0
Restructuring and impairment charges				2,783,000	[1]
Equity-based compensation				0
Gain on sale of oil and gas rights				0
Loss (gain) on sales of assets				0
Non-cash interest expense				0
Amortization of deferred financing costs				0
Other				0
Loss on extinguishment of debt				1,623,000	[1]
Changes in operating assets and liabilities:
Receivables, net				-300,000
Inventories				0
Accounts payable and accrued expenses				-198,000
Deferred revenue				0
Accrued compensation				0
Asset retirement obligations				0
Other assets and liabilities				-1,322,000
Net cash provided by operating activities				-1,820,000
Cash flows from investing activities:
Additions to property, plant and equipment				0
Change in restricted investments and bond collateral				0
Net proceeds from sales of assets				0
Insurance proceeds				0
Net cash used in investing activities				0
Cash flows from financing activities:
Borrowings from long-term debt, net of debt discount				175,000,000
Repayments of long-term debt				-135,822,000
Borrowings on revolving lines of credit				0
Repayment on revolving lines of credit				-23,000,000
Debt issuance costs and other refinancing costs				-8,437,000
Redemption of noncontrolling interest				0
Distributions to partners				0
Capital contributions from partners				0
Net cash provided by (used in) financing activities				7,741,000
Net increase (decrease) in cash and cash equivalent				5,921,000
Cash and cash equivalents, beginning of the year	0			5,921,000
Cash and cash equivalents, end of the year	5,921,000			5,921,000
Supplemental disclosures of cash flow information:
Cash paid for interest				2,922,000
Non-cash transactions:
Property, plant and equipment acquired with debt				0
Asset retirement obligations capitalized in mine development				0
Value of debt assigned to warrants				0
Market value of common units vested in LTIP				0
Kemmerer coal reserves contribution	33,152,000
Predecessor [Member]
Cash flows from operating activities:
Net loss	-24,155,000	-23,700,000	-26,053,000
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion and amortization	39,088,000	47,827,000	50,928,000
Accretion of asset retirement obligations	2,337,000	2,293,000	1,567,000
Amortization of intangible assets and liabilities, net	227,000	254,000	242,000
Restructuring and impairment charges	75,000	1,761,000	15,650,000
Equity-based compensation	4,559,000	1,441,000	1,262,000
Gain on sale of oil and gas rights	-232,000	-6,116,000	-6,329,000
Loss (gain) on sales of assets	14,000	-372,000	-1,692,000
Non-cash interest expense	7,744,000	4,094,000	0
Amortization of deferred financing costs	4,099,000	3,178,000	2,175,000
Other	-822,000	-3,352,000	-767,000
Loss on extinguishment of debt	-500,000	808,000	0
Changes in operating assets and liabilities:
Receivables, net	3,313,000	-6,062,000	8,596,000
Inventories	-1,161,000	-778,000	-554,000
Accounts payable and accrued expenses	-4,859,000	-2,881,000	-518,000
Deferred revenue	0	106,000	-2,300,000
Accrued compensation	-1,858,000	1,760,000	-905,000
Asset retirement obligations	-4,354,000	-8,222,000	-8,966,000
Other assets and liabilities	870,000	-2,111,000	-5,160,000
Net cash provided by operating activities	24,385,000	9,716,000	31,776,000
Cash flows from investing activities:
Additions to property, plant and equipment	-15,903,000	-22,332,000	-22,687,000
Change in restricted investments and bond collateral	4,456,000	-9,590,000	1,811,000
Net proceeds from sales of assets	3,194,000	6,424,000	12,417,000
Insurance proceeds	0	3,035,000	400,000
Net cash used in investing activities	-8,253,000	-22,463,000	-8,059,000
Cash flows from financing activities:
Borrowings from long-term debt, net of debt discount	-6,000	150,000,000	0
Repayments of long-term debt	-18,626,000	-56,072,000	-10,921,000
Borrowings on revolving lines of credit	22,500,000	53,588,000	51,000,000
Repayment on revolving lines of credit	-19,000,000	-126,088,000	-39,000,000
Debt issuance costs and other refinancing costs	-529,000	-9,569,000	-1,086,000
Redemption of noncontrolling interest	-3,560,000	0	0
Distributions to partners	0	0	-22,777,000
Capital contributions from partners	0	0	12,000
Net cash provided by (used in) financing activities	-19,221,000	11,859,000	-22,772,000
Net increase (decrease) in cash and cash equivalent	-3,089,000	-888,000	945,000
Cash and cash equivalents, beginning of the year	3,089,000	3,977,000	3,032,000
Cash and cash equivalents, end of the year	0	3,089,000	3,977,000	0
Supplemental disclosures of cash flow information:
Cash paid for interest	14,655,000	12,258,000	10,739,000
Non-cash transactions:
Property, plant and equipment acquired with debt	35,000	1,000,000	307,000
Asset retirement obligations capitalized in mine development	5,385,000	8,927,000	16,011,000
Value of debt assigned to warrants	0	7,879,000	0
Market value of common units vested in LTIP	1,320,000	330,000	849,000
Kemmerer coal reserves contribution	$0	$0	$0
[1]	See Note 3.

Organization_and_Presentation

Organization and Presentation	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Presentation	ORGANIZATION AND PRESENTATION
	Basis of Presentation and Principles of Consolidation
	The accompanying consolidated financial statements include the accounts and operations of the Partnership and its consolidated subsidiaries and are prepared in conformity with accounting principles generally accepted in the United States of America (“US GAAP”). WCC's cost of acquiring our GP has been pushed-down to establish a new accounting basis for us beginning in the last minutes of the year ended December 31, 2014. Accordingly, the accompanying consolidated financial statements are presented for two periods, Predecessor and Successor, which relate to the accounting periods preceding and succeeding the completion of the transaction. The Predecessor and Successor periods have been separated by a vertical line on the face of the consolidated financial statements to highlight the facts that the financial information for such periods has been prepared under two different historical-cost bases of accounting.
	Significant Relationships Referenced in Notes to Consolidated Financial Statements
	•	“We,” “us,” “our,” “WMLP,” or the "Partnership” means the business and operations of Westmoreland Resource Partners, LP, the parent entity, as well as its consolidated subsidiaries.
	•	Our “GP” means Westmoreland Resources GP, LLC, the general partner of Westmoreland Resource Partners, LP.
	Westmoreland Coal Company Transactions
	Acquisition of Oxford Resources GP, LLC
	On December 31, 2014, pursuant to a Purchase Agreement dated October 16, 2014, Westmoreland Coal Company, a Delaware corporation (“WCC”), acquired, for $33.5 million in cash, 100% of the equity of our GP from (i) the holders of all of our GP’s outstanding Class A Units, AIM Oxford Holdings, LLC (“AIM”) and C&T Coal, Inc. (“C&T”), (ii) the holders of all of our GP’s outstanding Class B Units, certain present and former executives of our GP, and (iii) the holders of all of the outstanding warrants for our GP’s Class B Units, certain of our former second lien term loan lenders and their affiliates (the “Warrantholders”). At the same time, WCC also acquired, for no additional consideration, (i) 100% of the Partnership’s outstanding subordinated units from AIM and C&T, which subordinated units were then converted to liquidation units, and (ii) 100% of the Partnership’s outstanding warrants for subordinated units from the Warrantholders, which warrants were then canceled by WCC.
	Contribution of Kemmerer Mine Fee Coal Reserves
	On December 31, 2014, pursuant to a Contribution Agreement dated October 16, 2014, WCC contributed to us 100% of the membership interests in Westmoreland Kemmerer Fee Coal Holdings, LLC (“WKFCH”). WKFCH holds fee simple interests in 30.4 million tons of coal reserves and related surface lands at WCC’s Kemmerer Mine in Lincoln County, Wyoming. Such contribution was made in exchange for 4,512,500 post-reverse split common units, resulting in WCC holding 79.0% of our outstanding limited partner units at March 3, 2015, after a 25% unit dividend.
	In connection with this contribution, WKFCH entered into a coal mining lease with respect to these coal reserves with a subsidiary of WCC pursuant to which we will earn a per ton royalty as these coal reserves are mined. Through the coal leasing arrangement, the mining of the Kemmerer Mine fee coal reserves will generate minimum royalty payments of $1 million per quarter from the start of 2015 through December 31, 2020 and $0.5 million per quarter thereafter through December 31, 2025.
	Name Changes
	In anticipation of the WCC transactions, we changed our name from Oxford Resource Partners, LP to Westmoreland Resource Partners, LP. Our GP also changed its name from Oxford Resources GP, LLC to Westmoreland Resources GP, LLC.
	Equity Restructuring of the Partnership
	On December 23, 2014 we received unitholder approval for the amendment and restatement of, and effective December 31, 2014 we amended and restated, our limited partnership agreement to, among other things:
	•	Effect a 12-to-1 reverse split of our common and general partner units;
	•	Convert all of our outstanding subordinated units to liquidation units (with no non-liquidating distribution or voting rights);
	•	Waive and eliminate our current cumulative common unit arrearages and also eliminate the concept of common unit arrearages going forward;
	•	Reset the minimum quarterly distribution to $0.1333 per common unit;
	•	Restructure the incentive distribution rights (the “IDRs”) held by our GP to provide that the IDRs will be entitled to receive (i) 13% of quarterly distributions over $0.1533 per unit and up to $0.1667 per unit; (ii) 23% of quarterly distributions over $0.1667 per unit and up to $0.2000 per unit; and (iii) 48% of quarterly distributions over $0.2000 per unit; and
	•	Suspend the distributions on the IDRs for six quarters, provided that such suspension may be reduced to three quarters if, during the suspension period, additional drop down transactions aggregating greater than $35.0 million in enterprise value are undertaken by us or our affiliates that are reasonably expected to provide accretion to per unit common unitholder distributions.
	Special Distribution to Public Unitholders
	Following the WCC transactions, we made a one-time special distribution to our public unitholders. The distribution was made on a pro rata basis, and consisted of a 25% unit dividend of 206,549 in additional post-reverse split common units. Throughout the consolidated financial statements, unit and per unit amounts have been adjusted for the 12-to-1 reverse unit split effective December 31, 2014.
	Debt Refinancing
	In connection with the WCC transactions, we entered into a new $295 million credit facility under a Financing Agreement (the “2014 Financing Agreement”) with the lenders party thereto and U.S. Bank National Association as Administrative and Collateral Agent to replace our existing $175 million credit facility consisting of (i) a first lien $75 million term loan and $25 million revolving credit facility and (ii) a second lien $75 million term loan. The new credit facility consists of a $175 million term loan, with an option for an additional up to $120 million in term loans for acquisitions if requested by us and approved by the issuing lenders. The 2014 Financing Agreement matures in December 2018 and contains customary financial and other covenants. It also permits distributions to our unitholders under specified circumstances. Borrowings under the 2014 Financing Agreement are secured by substantially all of our physical assets. Proceeds of the new credit facility were used to retire our then existing first and second lien credit facilities and to pay fees and expenses related to our new credit facility, with the limited amount of remaining proceeds being available as working capital.
	Organization
	WCC directly owns all the common units of our GP. WCC’s common stock trades on the Nasdaq under the symbol “WLB.”
	As of March 3, 2015, WCC and its consolidated subsidiaries owned, through their limited and general partner interests in us, an approximate 79.1% interest in us. In addition to any distributions it receives from its limited and general partner interests, WCC holds indirectly the incentive distribution rights in us held by our GP. Distributions were not permitted under our credit facilities in effect until the end of 2014, and no distributions were made in 2014.
	Westmoreland Resource Partners, LP is a Delaware limited partnership formed in August 2007. We are a low-cost producer and marketer of high-value thermal coal to United States (“U.S.”) utilities and industrial users, and we are the largest producer of surface mined coal in Ohio. We market our coal primarily to large electric utilities with coal-fired, base-load scrubbed power plants under long-term coal sales contracts. We focus on acquiring thermal coal reserves that we can efficiently mine with our large-scale equipment. Our reserves and operations are strategically located to serve our primary market area of Indiana, Kentucky, Michigan, Ohio, Pennsylvania and West Virginia.
	We operate in a single business segment and have four operating subsidiaries, Oxford Mining, Oxford Mining Company-Kentucky, LLC, WKFCH and Harrison Resources. All of our operating subsidiaries participate primarily in the business of utilizing surface mining techniques to mine domestic coal and prepare it for sale to our customers or lease our controlled coal reserves to others to mine.
	As of December 31, 2014, management estimates that we owned or controlled approximately 106.5 million tons of coal reserves, of which we have leased or subleased 54.7 million tons of both underground and surface reserves to others. The estimates are based on an initial evaluation, as well as subsequent acquisitions, dispositions, depletion of reserves, changes in available geological or mining data and other factors.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	Purchase and Pushdown Accounting
	WCC's acquisition of our GP was accounted for using the acquisition method under ASC 805, Business Combination. Under the acquisition method, the purchase price was allocated to the underlying tangible and intangible assets acquired and liabilities assumed based on their respective fair values. The allocation of the purchase price is preliminary pending the completion of various analyses and the finalization of estimates. During the measurement period (which is not to exceed one year from the acquisition date), additional assets or liabilities may be recognized if new information is obtained about facts and circumstances that existed as of the acquisition date that, if known, would have resulted in the recognition of those assets or liabilities as of that date. The preliminary allocation may be adjusted after obtaining additional information regarding, among other things, asset valuations, liabilities assumed and revisions of previous estimates. These adjustments may be significant and will be accounted for retrospectively.
	Per ASC 805-50-25-4 (effective November 18, 2014), we, as an acquiree of WCC through our GP, have the option to apply pushdown accounting in our consolidated financial statements when an acquirer (WCC) obtained control of us. We have chosen adopt pushdown accounting and will reflect purchase accounting adjustments in our consolidated financial statement.
	Cash
	Cash consists of cash held with reputable depository institutions and is stated at cost which approximates fair value. At times, such deposits may be in excess of the FDIC insurance limit. We have not experienced any losses in such accounts and believe we are not exposed to any significant credit risk relating to such amounts.
	Trade Receivables
	Trade receivables are recorded at the invoiced amount and do not bear interest. The Partnership evaluates the need for an allowance for doubtful accounts based on a review of collectability. There was no allowance for doubtful accounts as of December 31, 2014 and 2013.
	Inventory
	Inventory, which includes materials and supplies as well as raw coal, is stated at the lower of cost or market. Cost is determined using the average cost method. Coal inventory costs include labor, supplies, equipment, operating overhead and other related costs.
	Restricted Investments and Bond Collateral
	We had restricted cash related to Harrison Resources of $3,969 as of December 31, 2013, which is included in our consolidated balance sheets as Restricted investments and bond collateral. Harrison Resources’ cash, which is deemed to be restricted due to the limitations of its use for Harrison Resources’ operations, primarily relates to funds set aside for future reclamation obligations. There are not any further restrictions on Harrison Resources' cash following the redemption of the noncontrolling interest effective October 1, 2014. See the Noncontrolling Interest section of this Note 2 and Note 15.
	Exploration and Mine Development
	Exploration expenditures are charged to Cost of coal revenues as incurred, including costs related to drilling and study costs incurred to convert or upgrade mineral resources to reserves.
	At existing surface mines, additional pits may be added to increase production capacity. These expansions may require significant capital to purchase or relocate equipment, build or improve existing haul roads and create the initial cut to remove overburden for new pits at existing mines. If these pits operate in a separate and distinct area of the mine, the costs associated with initially uncovering coal for production are capitalized and amortized over the life of the developed pit consistent with coal industry practices. Once production has begun, mining costs are then expensed as incurred.
	Where new pits are routinely developed as part of a contiguous mining sequence, the Partnership expenses such costs as incurred. The development of a contiguous pit typically reflects the planned progression of an existing pit, thus maintaining production levels from the same mining area utilizing the same employee group and equipment.
	Property, Plant and Equipment
	Property, plant and equipment are recorded at cost or fair value as a result of purchase accounting as previously discussed. Expenditures that extend the useful lives of existing plant and equipment or increase productivity of the assets are capitalized. Maintenance and repair costs that do not extend the useful life or increase productivity of the asset are expensed as incurred. Coal reserves are recorded at cost, or at fair value originally in the case of acquired businesses and application of pushdown accounting.
	Coal reserves, mineral rights and mine development costs are depleted based upon estimated recoverable proven and probable reserves. Plant and equipment are depreciated on a straight-line basis over the assets’ estimated useful lives as follows:
		Years
	Buildings and tipple	25 - 39
	Machinery and equipment	1 - 12
	Vehicles	7-May
	Furniture and fixtures	7-Mar
	We assess the carrying value of our property, plant and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparing estimated undiscounted cash flows expected to be generated from such assets to their net book value. If net book value exceeds estimated cash flows, the asset is written down to fair value. When an asset is retired or sold, its cost and related accumulated depreciation and depletion are removed from the accounts. The difference between the net book value of the asset and proceeds on disposition is recorded as a gain or loss. Fully depreciated plant and equipment still in use are not eliminated from the accounts. Amortization of capital leases is included in Depreciation, depletion and amortization.
	Advanced Coal Royalties
	A portion of our reserves are leased. Advanced coal royalties are advance payments made to lessors under terms of lease agreements that are typically recoupable through an offset or credit against royalties payable on future production. We write-off advanced coal royalties when recoverability is no longer probable based on future mining plans.
	Deferred Financing Costs
	We capitalize costs incurred in connection with borrowings or establishment of credit facilities and issuance of debt securities. These costs are amortized as an adjustment to interest expense over the life of the borrowing or term of the credit facility using the effective interest method. These amounts are recorded in Deferred financing costs, net in the accompanying consolidated balance sheets.
	Financial Instruments
	Our financial instruments include cash, accounts receivable, restricted investments and bond collateral, accounts payable, fixed rate debt and variable rate debt. In 2012, we also had an interest rate swap agreement. We do not hold or purchase financial instruments or derivative financial instruments for trading purposes.
	Our financial instruments include fixed price forward contracts for diesel fuel. Our risk management policy allows us to purchase up to 80% of our unhedged diesel fuel gallons on fixed price forward contracts. These contracts meet the normal purchases and sales exclusion and therefore are not accounted for as derivatives. These forward fuel contracts usually have a term of 1 year or less, and we take physical delivery of all the fuel supplied under these contracts except in the case of one Illinois Basin contract which was modified in connection with its cancellation.
	Warrants
	In connection with our refinancing in June 2013, certain of the second lien lenders and lender affiliates received warrants entitling them to purchase common and subordinated units under a freestanding contract. The subordinated unit warrants were canceled on December 31, 2014. Pursuant to Financial Accounting Standards Board's Codification Topic 470-20, “Debt With Conversion and Other Options” (ASC 470-20), freestanding contracts that are settled in a company’s own stock, including common and subordinated unit warrants, are to be designated as an asset, liability or equity instrument. Both the common and subordinated unit warrants were determined to be liabilities and were recorded at fair value as determined using the Black-Scholes Pricing Model. ASC 470-20 further requires that the warrants' fair value be remeasured each reporting period, with the change in fair value being reported in the consolidated statements of operations. Fair value determinations prepared using the Black-Scholes Pricing Model require assumptions related to interest rates, unit price, exercise price, term and volatilities.
	Intangible Assets
	Identifiable intangible assets acquired in a business combination must be recognized and reported separately from goodwill. These intangible assets are amortized on a straight-line basis over the respective useful life of the asset. See Note 8 for further details.
	Deferred Revenue
	Deferred revenues represent funding received upon the negotiation of contracts for coal royalty and limestone sales. These deferred revenues are recognized as deliveries of the reserved coal or limestone are made in accordance with the contracts. At December 31, 2014, deferred revenue was adjusted to fair value of zero in purchase accounting since there is no future legal performance obligation of the Successor.
	Asset Retirement Obligations
	Our asset retirement obligations, or ARO, primarily consists of estimated costs to reclaim surface land and support facilities at our mines and in accordance with federal and state reclamation laws as established by each mining permit.
	We estimate ARO for final reclamation and mine closure based upon detailed engineering calculations of the amount and timing of the future costs for a third party to perform the required work. These estimates are based on projected pit configurations at the end of mining and are escalated for inflation, and then discounted at a credit adjusted risk-free rate. We record mineral rights associated with the initial recorded liability. Mineral rights are amortized based on the units of production method over the estimated recoverable, proven and probable reserves at the related mine, and the ARO is accreted to the projected settlement date. Changes in estimates could occur due to revisions of mine plans, changes in estimated costs, and changes in timing of the performance of reclamation activities. See Note 10.
	Income Taxes
	As a partnership, we are not a taxable entity for federal or state income tax purposes; the tax effect of our activities passes through to our unitholders. Therefore, no provision or liability for federal or state income taxes is included in our financial statements. Net income (loss) for financial statement purposes may differ significantly from taxable income (loss) reportable to our unitholders as a result of timing or permanent differences between financial reporting under US GAAP and the regulations promulgated by the Internal Revenue Service.
	Revenue Recognition
	Revenue from coal sales is recognized at the time title and risk of loss passes to the customer in accordance with the terms of the underlying sales agreements and after any contingent performance obligations have been satisfied. Coal sales prices are subject to premiums and reductions based on variations in coal quality delivered versus specifications in our coal supply contracts, but such adjustments are typically confirmed in a matter of days. Risk of loss typically transfers to the customer at the mine or dock, when the coal is loaded on the rail, barge, or truck.
	Royalty revenue relates to coal reserves which we lease to others and oil and gas rights. For the years ended 2014, 2013 and 2012, we received royalties of $0.3 million, $0.01 million and $1.5 million, respectively.
	Non-coal revenue consists primarily of clay and limestone sales, service fees, and other miscellaneous revenue. Clay and limestone sales relate to material we recover during the coal mining process and sell to third parties. Additionally service fees are earned for operating a coal unloading facility, providing river barge loading services, and hauling ash. Periodically, we recognize miscellaneous revenue related to lost coal claims that result from granting third-party right-of-way access through small portions of various mine complexes. In 2014, we also received $19.5 million from a former customer to compensate us for lost profits on a wrongfully terminated contract.
	Below-Market Coal Sales Contracts
	Our below-market coal sales contracts were acquired through the Phoenix Coal acquisition in 2009 and represent contracts for which the prevailing market price for the specified coal was in excess of the contract price. The fair value was based on discounted cash flows resulting from the difference between the below-market contract price and the prevailing market price at the date of acquisition. The fair value adjustments are amortized into coal sales on the basis of tons shipped over the terms of the respective contracts. Amortization of these below-market contracts included in revenue was $0.1 million and $0.6 million for the years ended December 31, 2013 and 2012, respectively. The current portion of the net carrying value of our below-market coal sales contracts was reflected in our consolidated balance sheets as Other current liabilities. No such amounts remained at December 31, 2013.
	Equity-Based Compensation
	Equity-based compensation expense is generally measured at the grant date and recognized as expense over the vesting period of the entire award. These costs are recorded in Cost of coal revenues and Selling and administrative in the accompanying consolidated results of operations. See Note 13.
	Noncontrolling Interest
	Noncontrolling interest is reported as a separate component of equity. The amount of net income (loss) attributable to the noncontrolling interest is recorded in Net income (loss) attributable to noncontrolling interest in our consolidated statements of operations. See Note 15.
	Earnings (Losses) Per Unit
	For purposes of our earnings per unit calculation, we apply the two class method. All outstanding limited partner units and general partner units share pro rata in income (loss) allocations and distributions, but only our general partner has voting rights. Limited partner units are further segregated into common units and subordinated units. As of December 31, 2014, the subordinated units were converted to liquidation units.
	Limited Partner Units: Basic earnings (losses) per unit are computed by dividing net income (loss) attributable to limited partners by the weighted average units outstanding, including unexercised participating warrants, during the reporting period. Diluted earnings (losses) per unit are computed similar to basic earnings (losses) per unit except that the weighted average units outstanding and net income (loss) attributable to limited partners are increased to include the dilutive effect of phantom units that would be issued assuming conversion to limited partnership units upon vesting. No such items were included in the computation of diluted loss per unit for the years ended 2014, 2013 or 2012 because we incurred a loss in each of these periods and the effect of inclusion would have been anti-dilutive.
	General Partner Units: Basic earnings (losses) per unit are computed by dividing net income (loss) attributable to our GP by the weighted average units outstanding, including unexercised participating warrants, during the reporting period. Diluted earnings (losses) per unit for our GP are computed similar to basic earnings (losses) per unit except that the net income (loss) attributable to the general partner units is adjusted for the dilutive impact of the phantom units. No such items were included in the computation of diluted loss per unit for the years ended 2014, 2013 or 2012 because we incurred a loss in each of these periods and the effect of inclusion would have been anti-dilutive.
	The table below shows the number of units that were excluded from the calculation of diluted loss per unit because their inclusion would be anti-dilutive to the calculation:
		Year Ended December 31,
		2014	2013	2012
	Long-term incentive plan units	70,298	42,694	371
	Accounting Pronouncement Effective in the Future
In April 2014, the FASB issued ASU 2014-8, Presentation of Financial Statements and Property, Plant and Equipment, which changes the presentation of discontinued operations on the statements of operations and other requirements for reporting discontinued operations. Under the new standard, a disposal of a component or a group of components of an entity is required to be reported in discontinued operations if the disposal represents a strategic shift that has (or will have) a major effect on an entity’s operations and financial results when the component meets the criteria to be classified as held for sale or is disposed. The amendments in this update also require additional disclosures about discontinued operations and disposal of an individually significant component of an entity that does not qualify for discontinued operations. The new guidance is effective for interim and annual periods beginning after December 15, 2014. We adopted ASU 2014-8 effective January 1, 2015.
In May 2014, the FASB issued ASU 2014-9, Revenue From Contracts With Customers, which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The ASU is based on the principle that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration which the entity expects to be entitled to receive in exchange for those goods or services. The ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to fulfill a contract. Entities have the option of using either a full retrospective or a modified retrospective approach for the adoption of the new standard. The new guidance is effective for the interim and annual periods beginning after December 15, 2016; early adoption is not permitted. We are currently assessing the impact that this standard will have on our consolidated financial statements.
In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements-Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern and to provide related footnote disclosures. Under GAAP, financial statements are prepared based on the presumption that the reporting organization will continue to operate as a going concern, except in limited circumstances. Financial reporting under this presumption is commonly referred to as the going concern basis of accounting. The going concern basis of accounting is critical to financial reporting because it establishes the fundamental basis for measuring and classifying assets and liabilities. Currently, GAAP lacks guidance about management’s responsibility to evaluate whether there is substantial doubt about the organization’s ability to continue as a going concern or to provide related footnote disclosures. This ASU provides guidance to an organization’s management, with principles and definitions that are intended to reduce diversity in the timing and content of disclosures that are commonly provided by organizations today in the financial statement footnotes. The new guidance is effective for the interim and annual periods beginning after December 15, 2016; early adoption is permitted for annual or interim reporting periods for which the financial statements have not previously been issued.
In August 2014, the FASB issued ASU 2014-17, Pushdown Accounting, which allows entities the option to elect pushdown of purchase accounting each time there is a change-in-control event in which an acquirer obtains control of the acquiree. If an acquiree does not initially elect to apply pushdown accounting upon a change-in-control event, it can subsequently elect to apply pushdown accounting to its most recent change-in-control event in a later reporting period as a change in accounting principle. Once made, the election to apply pushdown accounting is irrevocable. Entities applying pushdown accounting are required to measure the individual assets and liabilities of the acquired entity based on the measurement guidance in ASC 805, including the recognition of goodwill. However, any bargain purchase gain recognized by the acquirer should not be recognized in the acquiree’s income statement, but rather as an adjustment to additional paid-in capital. Acquisition-related debt is recognized by the acquiree only if the acquired entity is required to recognize a liability for debt in accordance with other applicable guidance. See our application of ASU 2014-17 in Note 3.
Reclassifications
Certain prior-year amounts have been reclassified in our consolidated balance sheets, statements of operations and statements of cash flows as of December 31, 2013 and 2012 to conform with the financial statement line items used by our GP's parent, WCC.

Acquisition_and_Pushdown_Accou

Acquisition and Pushdown Accounting	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Acquisition and Pushdown Accounting	ACQUISITION AND PUSHDOWN ACCOUNTING
	On December 31, 2014, pursuant to a Purchase Agreement dated October 16, 2014, WCC acquired, for $33.5 million in cash, 100% of the equity of our GP from (i) the holders of all of our GP’s outstanding Class A Units, AIM and C&T, (ii) the holders of all of our GP’s outstanding Class B Units, certain present and former executives of our GP, and (iii) the holders of all of the outstanding warrants for our GP’s Class B Units, the Warrantholders. At the same time, WCC also acquired, for no additional consideration, (i) 100% of the Partnership’s outstanding subordinated units from AIM and C&T, which subordinated units were then converted to liquidation units, and (ii) 100% of the Partnership’s outstanding warrants for subordinated units from the Warrantholders, which warrants were then canceled by WCC.
	The purchase consideration for our GP and control of our GP’s consolidated subsidiaries is estimated at $238.3 million, which included $33.5 million paid in cash, plus the assumption of approximately $194.0 million of liabilities. Additionally, we incurred acquisition-related costs of $5.5 million that have been expensed and are included in Selling and administrative in the accompanying consolidated results of operations.
	The acquisition of our GP was accounted for by WCC under the acquisition method of accounting that requires the total purchase consideration to be allocated to the assets acquired and liabilities assumed based on estimates of fair value. We have elected to apply pushdown accounting to our consolidated financial statements. By applying pushdown accounting, our financial statements also reflect these adjustments to fair value with a portion allocated to noncontrolling interest for the portion of us that is not owned directly by WCC.
	The allocation of the purchase price is preliminary pending the completion of various analyses and the finalization of estimates. During the measurement period (which is not to exceed one year from the acquisition date), additional assets or liabilities may be recognized if new information is obtained about facts and circumstances that existed as of the acquisition date that, if known, would have resulted in the recognition of those assets or liabilities as of that date. The preliminary allocation may be adjusted after obtaining additional information regarding, among other things, asset valuations, liabilities assumed and revisions of previous estimates. These adjustments may be significant and will be accounted for retrospectively.
	A summary of the estimated purchase consideration and a preliminary allocation of the estimated purchase consideration is as follows (in millions):
	Estimated purchase consideration
	Market value of limited partners' units	$	10.8
	Cash paid	33.5
	Total consideration	$	44.3
	Estimated fair value of liabilities assumed:
	Debt	$	160.1
	Asset retirement obligations	31.7
	Other liabilities	0.2
	Warrants	2
	Total estimated fair value of liabilities assumed	194
	Total estimated purchase consideration:	$	238.3
	Preliminary allocation of estimated purchase consideration:
	Working capital	$	14.7
	Land and mineral rights	38.6
	Plant and equipment	134
	Advanced coal royalities	9.2
	Restricted investments and bond collateral	10.6
	Intangible asset	31
	Other assets	0.2
	Total preliminary allocation of estimated purchase consideration:	$	238.3
	Subsequent to the acquisition of our GP, the following events occurred which are activity of the new owners or Successor entity. The aquisition triggered change of control provisions in the executives’ employment contracts which resulted in additional restructuring expenses. See Note 4. Subsequent to the transaction, we also refinanced our debt which included an early payment penalty included in debt extinguishment costs.

Restructuring_and_Impairment_C

Restructuring and Impairment Charges	12 Months Ended
	Dec. 31, 2014
Restructuring and Related Activities [Abstract]
Restructuring and Impairment Charges	RESTRUCTURING AND IMPAIRMENT CHARGES
	WCC Transactions Restructuring
	Concurrent with the WCC transactions, a restructuring plan was initiated to streamline operations and eliminate duplicate roles and responsibilities between us and WCC. At December 31, 2014, we recorded restructuring charges for employee termination benefits of $2.8 million. We expect to incur $0.6 million of additional restructuring costs as we complete our restructuring plan throughout the first half of 2015.
	WCC transactions restructuring accrual activity is summarized as follows:
		Oxford Resource Partners, LP (Predecessor)				Westmoreland Resource Partners, LP
						(Successor)
		As of December 31, 2014				For the Period						As of December 31, 2014
						31-Dec-14
		Liability				Charges			Payments			Liability
	Severance and other termination costs	$	—			$	2,783		$	—		$	2,783
	Illinois Basin Restructuring and Impairment
	In March 2012, we received a termination notice from a customer related to an 0.8 million ton per year coal supply contract fulfilled from our Illinois Basin operations. In response, we initially idled some of our Illinois Basin operations, terminated a significant number of employees related to such operations and substituted purchased coal for mined and washed coal on certain sales contracts. Subsequently over time, the remainder of our Illinois Basin operations were idled and the related employees terminated with the result that our Illinois Basin operations were fully idled as of December 31, 2013. During that period, we also sold some of our excess Illinois Basin equipment while redeploying most of the equipment to our Northern Appalachian operations, with such redeployment being completed during the first quarter of 2014. Additionally, we sold our Illinois Basin dock in April 2014. Finally, we are seeking to sell the remaining Illinois Basin equipment, consisting of a large-capacity shovel and several smaller pieces of equipment, and would consider offers to purchase the remaining coal reserves and/or facilities related to our Illinois Basin operations.
	Impairment Charges
	As a result of the restructuring described above, we recorded asset impairment charges of $12.8 million during 2012. These non-cash charges related to coal reserves, mine development assets and certain mining equipment. No such charges were recorded in the years ended December 31, 2014 and 2013, respectively.
	Restructuring Charges
	The restructuring related to our Illinois Basin operations was completed in March 2014. Restructuring charges of $0.1 million, $1.8 million and $2.9 million were incurred for the years ended December 31, 2014, 2013 and 2012, respectively. These charges included termination costs for employees, professional and legal fees, and transportation costs associated with moving idled equipment to our Northern Appalachian operations. The liabilities related to the restructuring are included in Other liabilities in our consolidated balance sheet as of December 31, 2013. There is no liability remaining for the Illinois Basin restructuring as of December 31, 2014.
	Our Illinois Basin restructuring accrual activity is summarized as follows:
		Oxford Resource Partners, LP (Predecessor)
		As of December 31, 2013			Period from January 1, 2014 through December 31, 2014						As of December 31, 2014
		Liability			Charges			Payments			Liability
	Severance and other termination costs	$	404		$	(42	)	$	(362	)	$	—
	Equipment relocation costs	252			117			(369		)	—
	Total cash restructuring charges	$	656		$	75		$	(731	)	$	—
	The following table summarizes the total Illinois Basin restructuring and impairment charges incurred over the course of the restructuring:
		Oxford Resource Partners, LP (Predecessor)
		Charges
		Period from January 1, 2014 through December 31, 2014			Incurred Through December 31,			Total Expected
					2014			Charges
	Cash:
	Severance and other termination costs	$	(42	)	$	1,846		$	1,846
	Professional and legal fees	—			1,021			1,021
	Equipment relocation costs	117			1,161			1,161
	Coal lease termination costs	—			23			23
	Total cash restructuring charges	75			4,051			4,051
	Non-cash:
	Coal lease termination costs	—			683			683
	Asset impairment	—			12,753			12,753
	Total non-cash restructuring charges	—			13,436			13,436
	Total restructuring and impairment charges	$	75		$	17,487		$	17,487

Inventory

Inventory	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventory	INVENTORY
	Inventory consisted of the following:
		Westmoreland Resource Partners, LP		Oxford Resource Partners, LP
		(Successor)		(Predecessor)
		December 31,		December 31,
		2014		2013
	Coal	$	6,590	$	5,957
	Fuel inventory	1,860		1,879
	Materials and supplies	5,563		6,004
	Total	$	14,013	$	13,840

Net_Property_Plant_and_Equipme

Net Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Net Property, Plant and Equipment	NET PROPERTY, PLANT AND EQUIPMENT
	Property, plant and equipment, net of accumulated depreciation, depletion and amortization, consisted of the following:
		Westmoreland Resource Partners, LP			Oxford Resource Partners, LP
		(Successor)			(Predecessor)
		December 31,			December 31,
		2014			2013
	Property, plant and equipment
	Land	$	4,040		$	3,016
	Mineral rights	67,675			107,651
	Total land and mineral rights	71,715			110,667
	Buildings and tipple	1,430			2,117
	Machinery and equipment	131,640			202,663
	Vehicles	527			4,522
	Furniture and fixtures	432			1,584
	Total plant and equipment	134,029			210,886
	Total gross, property, plant and equipment	205,744			321,553
	Less: accumulated depreciation, depletion and amortization	—			(177,127		)
	Net property, plant and equipment	$	205,744		$	144,426
	The amounts of depreciation expense related to owned and leased fixed assets, depletion expense related to owned and leased coal reserves, amortization expense related to mine development costs within mineral rights and amortization expense related to intangible assets for the respective years are as follows:
		For the Year Ended December 31,
		2014		2013				2012
	Depreciation	$	26,663	$	30,786			$	34,276
	Depletion	5,337		4,513				4,869
	Mine development amortization	7,088		12,528				11,783
	Intangible asset amortization(1)	227		254				242
		$	39,315	$	48,081			$	51,170
	(1)See Note 8.
	In June 2013 and April 2012, we completed the sale of certain oil and gas rights and land in eastern Ohio for $6.1 million and $6.3 million, respectively, which is recorded in Gain on sales of assets in our consolidated statements of operations for the years ended December 31, 2013 and 2012. As part of these transactions, we retained royalty rights equivalent to 20% of net revenue once the wells are producing. These rights started generating royalty revenue during the first quarter of 2014, which is recorded in Royalty revenues.

Operating_Leases

Operating Leases	12 Months Ended
	Dec. 31, 2014
Leases, Operating [Abstract]
Operating Leases	OPERATING LEASES
	We lease certain operating facilities and equipment under non-cancelable lease agreements that expire on various dates through 2019. Generally, the lease terms range from three to ten years. As of December 31, 2014, aggregate lease payments under operating leases that have initial or remaining non-cancelable lease terms in excess of one year are set forth below:
	For the years ending December 31, 2015	$	6,189
	2016	2,871
	2017	877
	2018	227
	2019	225
	For the years ended December 31, 2014, 2013 and 2012, we incurred lease expenses of $8,835, $8,591 and $7,118, respectively.
	We have also entered into various coal reserve lease agreements under which advance royalty payments are made. Most of these advance royalty payments are recoupable against future royalty payments otherwise due based on production. Such payments are capitalized as Advanced coal royalties at the time of payment, and are recoupable through an offset or credit against royalties payable on future production.

Intangible_Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	INTANGIBLE ASSETS
	Identifiable intangible assets acquired in a business combination must be recognized and reported separately from goodwill. In December 2014, as part of the preliminary purchase accounting consideration discussed in Note 3, we have determined that the most significant acquired identifiable intangible asset is related to a beneficial lease agreement. Intangible assets result from more favorable market prices than contracted prices in lease agreements as measured during a business combination. Our intangible asset is amortized on a straight-line basis over the remaining term of the lease agreement.
		Westmoreland Resource Partners, LP (Successor)
		As of December 31, 2014
		Estimated		Cost		Accumulated		Net Carrying
		Remaining				Amortization		Value
		Life (years)
	Intangible assets
	Favorable lease agreement	15		$	31,000	$	—	$	31,000
		Oxford Resource Partners, LP (Predecessor)
		As of December 31, 2013
		Estimated		Cost		Accumulated		Net Carrying
		Remaining				Amortization		Value
		Life (years)
	Intangible assets
	Customer relationships	13		$	3,315	$	2,127	$	1,188
	Customer relationships represent intangible assets that were recorded at fair value when we acquired Oxford Mining and its subsidiaries in August 2007. The net carrying value of our customer relationships is reflected in our consolidated balance sheets as Intangible assets, net. We amortized these assets over the expected life of the respective customer relationships. This intangible asset was adjusted to fair value in purchase accounting for the WCC transactions at December 31, 2014. Amortization related to customer relationships totaled $227, $254, and $242 for the years ended December 31, 2014, 2013 and 2012, respectively.
	Expected amortization of intangible assets will be approximately:
	For the years ending December 31, 2015	$	2,067
	2016	2,067
	2017	2,067
	2018	2,067
	2019	2,067
	Thereafter	20,665
	We evaluate our intangible assets for impairment when indicators of impairment exist. For the years ended December 31, 2014, 2013 and 2012, there were no indicators of impairment present for our intangible assets.

Other_Current_Liabilities

Other Current Liabilities	12 Months Ended
	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Other Current Liabilities	OTHER CURRENT LIABILITIES
	Other current liabilities consisted of the following:
		Westmoreland Resource Partners, LP		Oxford Resource Partners, LP
		(Successor)		(Predecessor)
		December 31,		December 31,
		2014		2013
	Accrued interest	$	45	$	1,424
	Accrued royalties	809		1,062
	Restructuring reserve	2,783		—
	Other	370		971
	Total	$	4,007	$	3,457

Asset_Retirement_Obligation

Asset Retirement Obligation	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligation	ASSET RETIREMENT OBLIGATIONS
	As previously indicated, our asset retirement obligations arise from SMCRA and similar state statutes, which require that mine property be restored in accordance with specified standards and an approved reclamation plan. The required reclamation activities to be performed are outlined in our mining permits. These activities include reclaiming the pit and support acreage, as well as stream mitigation.
	As of December 31, 2014, our ARO totaled $31.7 million, including amounts reported as current liabilities. While the precise amount of these future costs cannot be determined with certainty, we estimate that, as of December 31, 2014, the aggregate undiscounted cost of final ARO is $42.4 million.
	Activities affecting the liability for ARO for the respective years are as follows:
		Year Ended December 31,
		2014			2013
	Asset retirement obligations, January 1,	$	31,654		$	29,013
	Accretion	2,337			2,293
	Changes resulting from additional mines	5,171			3,671
	Changes due to amount and timing of reclamation	(2,480		)	5,333
	Payments	(4,997		)	(8,656		)
	Asset retirement obligations, December 31,	31,685			31,654
	Less current portion	(7,783		)	(5,996		)
	Asset retirement obligations, less current portion	$	23,902		$	25,658
	In 2014, the revisions in discounted estimated cash flows resulted in a net increase in the asset retirement obligations of $2.7 million. Of this amount, $5.2 million related to five new mines, $0.1 million related to reclamation work in progress at recently closed mines offset in part by a $2.6 million decrease related to updated cost estimates for pond removal, grading and water treatment.
	In 2013, the revisions in discounted estimated cash flows resulted in a net increase in the asset retirement obligations of $9.0 million. Of this amount, $3.7 million related to four new mines, $4.0 million related to reclamation work in progress at recently closed mines and the remaining $1.3 million related to updated cost estimates for pond removal, grading and water treatment.
	Adjustments to the liability for asset retirement obligations due to such revisions generally result in corresponding adjustments to the related mine development assets for active and new mines.

LongTerm_Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2014
Disclosure Text Block [Abstract]
Long-Term Debt	LONG-TERM DEBT
	Debt consisted of the following:
		Westmoreland Resource Partners, LP			Oxford Resource Partners, LP
		(Successor)			(Predecessor)
		December 31,			December 31,
		2014			2013
	First lien debt:
	Term loan	$	175,000		$	69,321
	Revolver	—			19,500
	Total first lien debt	175,000			88,821
	Second lien debt:
	Term loan	—			75,000
	Paid-in-kind interest	—			2,318
	Debt discount, net	—			(6,456		)
	Total second lien debt, net of debt discount	—			70,862
	Notes payable	35			3,593
	Total debt	175,035			163,276
	Less current portion	(6		)	(7,901		)
	Long-term debt	$	175,029		$	155,375
	Credit Facilities Generally
	In June 2013, we closed on $175 million of credit facilities that were comprised of (i) a first lien credit facility consisting of a $75 million term loan and a $25 million revolver under a first lien financing agreement (the “First Lien Financing Agreement”) and (ii) a second lien credit facility consisting of a $75 million term loan (with an option for an additional $10 million term loan if requested by us and approved by the issuing second lien lender) under a second lien financing agreement (the “Second Lien Financing Agreement,” and collectively with the First Lien Financing Agreement, the “2013 Financing Agreements”).
	The first lien credit facility was scheduled to mature in September 2015 with an option to extend to June 2016, and the second lien credit facility was scheduled to mature in December 2015 with an option to extend to September 2016, in both cases if certain conditions were met.
	In connection with the Second Lien Financing Agreement, certain lenders and lender affiliates (the "Warrantholders") received warrants entitling them to purchase 162,972 common units and 151,182 subordinated units at $0.12 per unit (unit and per unit amounts have been adjusted for the 12-to-1 reverse unit split effective December 31, 2014). The warrants, classified as a liability, were recorded at their fair value of $7.9 million at issuance as a debt discount. The warrants are subsequently marked to fair value with the change in fair value reported in earnings. This discount was being amortized through interest expense over the life of our second lien credit facility using the effective interest method. For the years ended December 31, 2014 and 2013, amortization of the debt discount totaled $3.0 million and $1.5 million, respectively.
	All subordinated unit warrants were canceled on January 1, 2015 in connection with the WCC transactions. Accelerated vesting of LTIP units just prior to the WCC transactions triggered anti-dilution provisions in the common warrant agreement and 3,585 additional post-split warrants were issued.
	On December 31, 2014, we closed on a new credit facility under a Financing Agreement (the “2014 Financing Agreement”) with the lenders party thereto and U.S. Bank National Association as Administrative and Collateral Agent. The new credit facility consists of a $175 million term loan, with an option for an additional up to $120 million in term loans for acquisitions if requested by us and approved by the issuing lenders. The new credit facility matures in December 2018. The 2014 Financing Agreement contains customary financial and other covenants. Borrowings under the 2014 Financing Agreement are secured by substantially all of our physical assets. Proceeds of the new credit facility were used to retire our then existing first and second lien credit facilities and to pay fees and expenses related to our new credit facility, with the limited amount of remaining proceeds being available as working capital.
	As of December 31, 2014, we had a term loan of $175 million outstanding under the 2014 Financing Agreement. Borrowings on such term loan bears interest at a variable rate per annum equal to, at our option, the London Interbank Offered Rate (as defined in the 2014 Financing Agreement) (“LIBOR”) (floor of 0.75% plus 8.5%) or the Reference Rate (as defined in the 2014 Financing Agreement). As of December 31, 2014, the 2014 Financing Agreement had a cash interest rate of 9.25%, consisting of the LIBOR floor (0.75%) plus 8.5%.
	The 2014 Financing Agreement also provides for “PIK Interest” (paid-in-kind interest as defined in the 2014 Financing Agreement) at a variable rate per annum between 1.00% and 3.00% based on our total net leverage ratio (as defined in the 2014 Financing Agreement). The rate of PIK Interest is recalculated on a quarterly basis with the PIK Interest added quarterly to the then-outstanding principal amount of the term loan under the 2014 Financing Agreement. PIK Interest under the 2014 Financing Agreement was inconsequential for the year ended December 31, 2014.
	As a result of our refinancing with the 2014 Financing Agreement, we recorded a $1.6 million loss on extinguishment of debt in the year ended December 31, 2014 as it pertains to cost associated with repayment of the debt under the 2013 Financing Agreements.
	As of December 31, 2014, we were in compliance with all covenants under the terms of the 2014 Financing Agreement.
	2013 Financing Agreements
	Under the 2013 Financing Agreements, we were required to make quarterly principal payments of $1.3 million on the first lien credit facility and $0.2 million on the second lien credit facility until maturity. Principal repayments totaled $15.1 million and $5.7 million for the first lien financing agreement during 2014 and 2013, respectively, including required repayment from certain proceeds we received. Principal repayments totaled $0.4 million for the second lien financing agreement during 2014 and no payments were due in 2013. The outstanding principal and accrued interest under the 2013 Financing Agreements were paid in full with proceeds from borrowings under the 2014 Financing Agreement on December 31, 2014.
	Our second lien credit facility also provided for PIK Interest (paid-in-kind interest as defined in the Second Lien Financing Agreement) at the rate of 5.75%. PIK Interest is added quarterly to the then-outstanding principal amount of the term loan as additional principal obligations. For the year ended December 31, 2014 and 2013, PIK Interest related to the second lien credit facility totaled $4.6 million and $2.3 million, respectively.
	Debt Maturity Table
	The total debt of the Partnership matures as follows:
	During the years ending December 31, 2015	$	6
	2016	29
	2017	—
	2018	175,000
		$	175,035
	Deferred Financing Costs
	We capitalized $7.0 million of deferred financing costs related to the 2014 Financing Agreement during the year ended December 31, 2014, and $9.6 million of deferred financing costs related to the 2013 Financing Agreements during the year ended December 31, 2013. These costs, included in Deferred financing costs, net , represent fees paid to lenders and advisors and for legal services.
	Amortization of deferred financing costs included in interest expense was $4.1 million, $3.2 million and $2.2 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	Selling and administrative expenses for 2013 included $0.7 million of fees paid to advisors and for legal services related to refinancing our then credit facility with the 2013 Financing Agreements, and $2.4 million of fees paid to lenders and advisors and for legal services related to our failed attempt to refinance our then credit facility under the previous credit agreement. There were no such expenses during the years ended December 31, 2014 and 2012.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	FAIR VALUE OF FINANCIAL INSTRUMENTS
	Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. We disclose the fair value of financial instruments where practicable. The carrying amounts of cash equivalents, accounts receivable and accounts payable reflected on the consolidated balance sheets approximate the fair value of these instruments due to the short duration to their maturities. Long-term debt fair value estimates are based on observed prices for securities with an active trading market when available (Level 2) and otherwise using discount rate estimates based on interest rates as of December 31, 2014 (Level 3).
	The estimated fair value of our debt are as follows:
		Westmoreland Resource Partners, LP				Oxford Resource Partners, LP
		(Successor)				(Predecessor)
		As of December 31, 2014				As of December 31, 2013
		Carrying		Fair Value		Carrying		Fair Value
		Amount				Amount
	Fixed rate debt	$	35	$	33	$	3,593	$	3,386
	Variable rate debt	175,000		175,000		159,683		159,683
	We utilize fair value measurement guidance that, among other things, defines fair value, requires enhanced disclosures about assets and liabilities carried at fair value and establishes a hierarchical disclosure framework based upon the quality of inputs used to measure fair value. We have elected not to measure any additional financial assets or liabilities at fair value, other than those required to be recorded at fair value.
	The financial instruments measured at fair value on a recurring basis are summarized below:
		Westmoreland Resource Partners, LP (Successor)
		Fair Value Measurements as of December 31, 2014
		Quoted Prices in Active Markets for Identical Asset or Liability		Significant Other		Significant
				Observable Inputs		Unobservable
						Inputs
	Description	(Level 1)		(Level 2)		(Level 3)
	Assets:
	Restricted investments and bond collateral	$	10,621	$	—	$	—
	Liabilities:
	Warrants	—		1,981		—
		Oxford Resource Partners, LP (Predecessor)
		Fair Value Measurements as of December 31, 2013
		Quoted Prices in Active Markets for Identical Asset or Liability		Significant Other		Significant
				Observable Inputs		Unobservable
						Inputs
	Description	(Level 1)		(Level 2)		(Level 3)
	Assets:
	Restricted investments and bond collateral	$	15,177	$	—	$	—
	Liabilities:
	Warrants	—		4,599		—
	The warrants are fair valued at each balance sheet date using the Black-Scholes model. At December 31, 2014, the fair value of each warrant was $11.88, based on the following assumptions: spot price of $12 per unit, exercise price of $0.12 per unit, term of 3.5 years, volatility of 84% and a five-year treasury rate of 1.65%.

LongTerm_Incentive_Plan

Long-Term Incentive Plan	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Long-Term Incentive Plan	LONG-TERM INCENTIVE PLAN
	Under our LTIP, we recognize equity-based compensation expense over the vesting period of the units. These units are subject to conditions and restrictions as determined by our Compensation Committee, including continued employment or service. Historically, these units generally vested in equal annual increments over four years with accelerated vesting of the first increment in certain cases. Beginning in 2012, some of the units granted to executive officers vested based on specified performance criteria.
	For the years ended December 31, 2014, 2013 and 2012, we recognized equity-based compensation expense of $4,559, $1,441 and $1,262. These amounts are included in Cost of coal revenues and Selling and administrative expenses. The change in control related to the WCC transactions triggered accelerated vesting of the remaining unvested units and all related expenses were recognized in the Predecessor period. Therefore, no units remain unvested at December 31, 2014.
	The following table summarizes additional information concerning our unvested LTIP units:
		Units		Weighted
				Average
				Grant Date
				Fair Value
	Unvested balance at December 31, 2012	21,497		$	140.08
	Granted	36,583		47.79
	Issued	(9,657	)	68.93
	Surrendered	(1,824	)	163.06
	Unvested balance at December 31, 2013	46,599		81.47
	Granted	125,363		14.42
	Issued	(108,696	)	33.03
	Surrendered	(63,266	)	32.98
	Unvested balance at December 31, 2014	—		—
	The value of LTIP units vested during the years ended December 31, 2014, 2013 and 2012 was $5,638, $963 and $944, respectively.

Earnings_Losses_Per_Unit

Earnings (Losses) Per Unit	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings (Losses) Per Unit	EARNINGS (LOSSES) PER UNIT
	The computation of basic and diluted earnings (losses) per unit under the two class method for limited partner units and general partner units is presented as follows:
		Westmoreland Resource Partners, LP			Oxford Resource Partners, LP
		(Successor)			(Predecessor)
		Period of			Period from			For the Year Ended December 31,
		December 31,			1-Jan-14
		2014			Through
					December 31,
					20014			2013			2012
	Limited partner units
	Average units outstanding:
	Basic	5,671,644			2,063,983			1,898,040			1,725,996
	Effect of equity-based compensation	N/A			N/A			N/A			N/A
	Diluted (1)(2)	5,671,644			2,063,983			1,898,040			1,725,996
	Net loss allocated to limited partners
	Basic	$	(4,379	)	$	(22,500	)	$	(24,470	)	$	(26,273	)
	Diluted	(4,379		)	(22,500		)	(24,470		)	(26,273		)
	Net loss per limited partner unit
	Basic	$	(0.72	)	$	(10.92	)	$	(12.84	)	$	(15.24	)
	Diluted (1)(2)	(0.72		)	(10.92		)	(12.84		)	(15.24		)
	General partner units
	Average units outstanding:
	Basic and diluted (1)(2)	35,291			35,291			35,302			35,217
	Net loss allocated to general partner
	Basic	$	(27	)	$	(385	)	$	(455	)	$	(535	)
	Diluted	(27		)	(385		)	(455		)	(535		)
	Net loss per general partner unit
	Basic	$	(0.72	)	$	(10.92	)	$	(12.84	)	$	(15.24	)
	Diluted (1)(2)	(0.72		)	(10.92		)	(12.84		)	(15.24		)
	Distributions paid per unit:
	Limited partners:
	Common	$	—		$	—		$	—		$	18.15
	Subordinated	—			—			—			7.65
	General partner	—			—			—			12.9
	(1)	Unvested LTIP units are not dilutive units for the years and periods presented herein, but could be in the future.
	(2)	Unvested LTIP units are not anti-dilutive units either. Anti-dilutive units are not used in calculating diluted average units.

Noncontrolling_Interest

Noncontrolling Interest	12 Months Ended
	Dec. 31, 2014
Noncontrolling Interest [Abstract]
Noncontrolling Interest	NONCONTROLLING INTEREST
	Harrison Resources, a limited liability company, was formed in March 2006 by Oxford Mining to acquire coal properties, develop mine sites and mine coal for sale to customers. Effective January 30, 2007, 49% of Harrison Resources was sold to an affiliate of CONSOL Energy, CONSOL of Ohio LLC ("Consol").
	Effective October 1, 2014, Oxford Mining entered into and closed under a membership interest redemption agreement with Harrison Resources and CONSOL under which Harrison Resources redeemed all of CONSOL’s interest in Harrison Resources. As a result of the redemption Oxford Mining owns 100% of Harrison Resources. In connection with the redemption, Harrison Resources acquired 0.9 million tons of coal reserves from a CONSOL affiliate, and also options to purchase an aggregate of 5.6 million additional tons of coal reserves from a CONSOL affiliate. These tons are in addition to the 1.7 million tons of coal reserves already owned by Harrison Resources. Harrison Resources paid total consideration of $3.6 million in these transactions.
	Harrison Resources’ revenues, which are included in our consolidated statements of operations, were $23,341, $34,100 and $34,518 for the years ended December 31, 2014, 2013 and 2012, respectively. Oxford Mining had a services agreement with Harrison Resources under which we performed mining and reclamation services for agreed-upon per ton prices. Additionally, Oxford Mining had a broker agreement with Harrison Resources under which we marketed the coal.
	Harrison Resources’ cash, which is deemed to be restricted, primarily relates to funds set aside for reclamation obligations in the amount of $3,969 as of December 31, 2013. The amount of such funds is included in our consolidated balance sheets as Restricted investments and bond collateral.
	Harrison Resources’ total net assets as of December 31, 2013 were $10,140. Noncontrolling interest, which represents the 49% of Harrison Resources owned by CONSOL, consisted of the following:
		Oxford Resource Partners, LP
		(Predecessor)
		For the Year Ended December 31,
		2014			2013
	Beginning balance	$	4,969		$	3,744
	Net (loss) income	(1,270		)	1,225
	Additional paid in capital	(99		)	—
	Redemption payment	(3,600		)	—
	Ending balance	$	—		$	4,969

Workers_Compensation_and_Black

Workers' Compensation and Black Lung	12 Months Ended
	Dec. 31, 2014
Workers Compensation And Black Lung [Abstract]
Workers Compensation And Black Lung	WORKERS’ COMPENSATION AND BLACK LUNG
	We have no liabilities under state statutes and the Federal Coal Mine Health and Safety Act of 1969, as amended, to pay black lung benefits to eligible employees, former employees and their dependents. Under the Black Lung Benefits Revenue Act of 1977, as amended in 1981, each coal mine operator must pay federal black lung benefits to claimants who are current and former employees and also make payments to a trust fund for the payment of benefits and medical expenses to claimants who last worked in the coal industry prior to January 1, 1970. The trust fund is funded by an excise tax on production of up to $1.10 per ton for deep-mined coal and up to $0.55 per ton for surface-mined coal, with neither amount to exceed 4.4% of the gross sales price for the coal. For the years ended December 31, 2014, 2013 and 2012, we recorded $2.9 million, $3.2 million and $3.6 million, respectively, in our cost of coal revenues related to this excise tax.
	With regard to workers’ compensation, we are insured through state sponsored programs or an insurance carrier where there is no state sponsored program.

Retirement_Plan

Retirement Plan	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Retirement Plan	RETIREMENT PLAN
	We maintain a 401(k) plan for the benefit of our employees. For the year ended December 31, 2012, we committed to and made an employer contribution at 4% of qualified wages totaling $1.9 million. For the years ended December 31, 2014 and 2013, we did not commit to make and we did not and/or are not making any discretionary employer contribution to the 401(k) plan.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES
	Coal Sales Contracts
	We are committed under long-term contracts to sell coal that meets certain quality requirements at specified prices. Many of these prices are subject to cost pass-through or cost adjustment provisions that mitigate some risk from rising costs. Quantities sold under some of these contracts may vary from year to year within certain limits at the option of the customer or us. As of December 31, 2014, the remaining terms of our long-term contracts range from one to two years.
	Purchase Commitments
	From time to time, we purchase coal from third parties in order to meet quality or delivery requirements under our customer contracts. We buy coal on the spot market, and the cost of that coal is dependent upon the market price and quality of the coal. We previously had a long-term purchase contract for 0.4 million tons of coal per year with a separate supplier who had asserted that the contract had terminated by its terms. We entered into a settlement agreement with the supplier in February 2013 under which the parties agreed to terminate the contract with the supplier making a one-time payment of $2.1 million to us, which payment was recorded in Non-coal revenues.
	Transportation
	We depend upon barge, rail and truck transportation systems to deliver coal to our customers. We have a rail transportation contract that has been amended and extended through March 31, 2015.
	401(k) Plan
	The GP did not make a commitment to fund an employer contribution to our 401(k) plan for the year ended December 31, 2013, and consequently no such contribution has been or will be made. For the year ended December 31, 2014, the GP made no commitment to fund an employer contribution to our 401(k) plan and will not make any such contribution.
	Surety and Performance Bonds
	As of December 31, 2014, we had $34.6 million in surety bonds outstanding to secure certain reclamation obligations which were collateralized by cash deposits of $9.1 million. Such cash collateral is included in Restricted investments and bond collateral on our consolidated balance sheets and Change in restricted investments and bond collateral within investing activities on our consolidated statements of cash flow. Additionally, we had road bonds totaling $0.5 million and performance bonds totaling $2.9 million outstanding to secure contractual performance. We believe these bonds will expire without any claims or payments thereon and therefore will not have a material adverse effect on our financial position, liquidity or operations.
	Legal
	In July 2014, we concluded litigation, with a former customer who wrongfully terminated its coal supply agreement with us, by entering into a settlement agreement under which the former customer paid us $19.5 million to compensate us for lost profits on coal sales to it due to the termination. We believe this settlement amount substantially compensates us for the damages we incurred due to the wrongful termination.
	From time to time, we are involved in various legal proceedings arising in the ordinary course of business. We accrue for such liabilities when it is probable that future costs (including legal fees and expenses) will be incurred and such costs can be reasonably estimated. Accruals are based on developments to date; management's estimates of the outcomes of these matters; our experience in contesting, litigating and settling similar matters; and any related insurance coverage. While the ultimate outcome of these proceedings cannot be predicted with certainty, we have accrued $0.5 million to resolve various claims as of December 31, 2014, of which $0.3 million, net, was accrued during 2014.
	Guarantees
	Our GP and the Partnership guarantee certain obligations of our subsidiaries. We believe that these guarantees will expire without any liability to the guarantors, and therefore will not have a material adverse effect on our financial position, liquidity or operations.

Concentration_of_Credit_Risk_a

Concentration of Credit Risk and Major Customers	12 Months Ended
	Dec. 31, 2014
Risks and Uncertainties [Abstract]
Concentration of Credit Risk and Major Customers	CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS
	We have a credit policy that establishes procedures to determine creditworthiness and credit limits for customers. Generally, credit is extended based on an evaluation of the customer’s financial condition. Collateral is not generally required, unless credit cannot be established.
	In 2014 and 2013, we marketed our coal principally to electric utilities, electric cooperatives, municipalities and industrial customers in Indiana, Kentucky, Michigan, Ohio, Pennsylvania and West Virginia. As of December 31, 2014 and 2013, accounts receivable from electric utilities totaled $16.3 million and $19.6 million, respectively, or 72.0% and 79.5% of total receivables, respectively. The following table shows the amount of sales to each customer (in each year where applicable, a “Major Customer”) which individually accounted for greater than 10% of sales in any of the years ended December 31, 2014, 2013 and 2012, with a portion of these sales being facilitated by coal brokers.
		Oxford Resource Partners, LP
		(Predecessor)
		Revenues for the Year Ended December 31,
	Customer	2014		2013		2012
		(in millions)
	American Electric Power	$	167.6	$	146.3	$	128.8
	First Energy	48.7		69.2		85.8
	East Kentucky Power Cooperative	42.3		41.4		56.6
	The Major Customers in 2014, 2013 and 2012, in the aggregate, represented 80.2%, 74.1% and 72.6%, respectively, of our total sales in the applicable year. The Major Customers in each of 2014 and 2013, in the aggregate, represented 78.9% and 81.5% of the outstanding accounts receivable at December 31, 2014 and 2013, respectively.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS
	In connection with our formation in August 2007, the Partnership and Oxford Mining entered into an administrative and operational services agreement (the “Services Agreement”) with our GP. The Services Agreement is terminable by either party upon thirty days’ written notice. Under the terms of the Services Agreement, our GP provides services through its employees to us and is reimbursed for all related costs incurred on our behalf. Our GP provides us with services such as general administrative and management, human resources, legal, information technology, finance and accounting, corporate development, real property, marketing, engineering, operations (including mining operations), geological, risk management and insurance services. Pursuant to the Services Agreement, the primary reimbursements to our GP were for costs related to payroll. Reimbursable costs under the Services Agreement totaling $0.6 million were included in accounts payable as of each of December 31, 2014 and 2013, respectively.
	In connection with the WCC transactions discussed in Note 1, WKFCH entered into a coal mining lease with respect to coal reserves at WCC’s Kemmerer Mine in Lincoln County, Wyoming with a subsidiary of WCC. Under this lease, we will earn a per ton royalty as these coal reserves are mined. Through the coal leasing arrangement, the mining of the Kemmerer Mine fee coal reserves will generate minimum royalty payments of $1 million per quarter from the start of 2015 through December 31, 2020 and $0.5 million per quarter thereafter through December 31, 2025.
	We sell clay and small quantities of coal to Tunnell Hill Reclamation, LLC (“Tunnell Hill”), a company that is indirectly owned by Mr. Charles Ungurean, Mr. Thomas Ungurean, and AIM. Messrs. Charles and Thomas Ungurean own C&T which owned 17.8% of the Partnership and 33.5% of our GP prior to the WCC transactions at December 31, 2014. AIM owned 35.0% of the Partnership and 65.8% of our GP prior to the WCC transactions at December 31, 2014. We also sold equipment to Tunnell Hill for $877 in 2012. Sales to Tunnell Hill were $0.6 million, $0.4 million and $0.2 million for the years ended December 31, 2014, 2013 and 2012, respectively. Additionally, we provided contracted services to Tunnell Hill totaling $0.6 million in 2014, while there were no contracted services provided during 2013 and 2012. Accounts receivable from Tunnell Hill were zero and $0.1 million for the years ended December 31, 2014 and 2013, respectively.
	From time to time for business purposes, we chartered the use of various airplanes from Zanesville Aviation located in Zanesville, Ohio. Additionally, C&T owns an airplane that it leases to Zanesville Aviation and Zanesville Aviation uses that airplane in providing charter services to its customers, including us at times. During the years 2014, 2013 and 2012, we paid Zanesville Aviation an aggregate of $0.02 million, $0.1 million and $0.1 million, respectively.

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION
	We operate in one business segment. We operate surface coal mines in Northern Appalachia and, through December 2013, in the Illinois Basin and sell high-value thermal coal to utilities, industrial customers, municipalities and other coal-related entities primarily in the eastern United States. Our operating and executive management reviews and bases its decisions upon consolidated reports. Three of our operating subsidiaries extract coal utilizing surface-mining techniques and prepare it for sale to their customers. Such operating subsidiaries share customers and a particular customer may receive coal from any one of such operating subsidiaries. We also lease or sublease coal reserves to others through Oxford Mining and WKFCH in exchange for a per ton royalty rate.

Supplemental_Quarterly_Financi

Supplemental Quarterly Financial Information - (Unaudited) Supplemental Quarterly Financial Information - (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Supplemental Quarterly Financial Information	SUPPLEMENTAL QUARTERLY FINANCIAL INFORMATION - (Unaudited)
	A summary of our unaudited consolidated quarterly operating results in 2014 and 2013 is as follows:
		Westmoreland Resource Partners, LP
		(Successor)
		2014
		Period of December 31			Total
	Total revenues	$	—		$	—
	Net (loss) income from operations	(2,783		)	(2,783		)
	Net (loss) income attributable to WMLP unitholders	(4,406		)	(4,406		)
	Net (loss) income allocated to general partner	(28		)	(28		)
	Net (loss) income allocated to limited partners	(4,378		)	(4,378		)
	(Loss) income per limited partner unit:
	Basic	$	(0.72	)	$	(0.72	)
	Diluted	$	(0.72	)	$	(0.72	)
		Oxford Resource Partners, LP
		(Predecessor)
		For the Three Months Ended
		March 31,			June 30,			Sept. 30,			Period from October 1, 2014 through December 31,			Period from January 1, 2014 through December 31,
		2014			2014			2014			2014			2014
	Total revenues	$	78,004		$	82,001		$	94,507		$	67,751		$	322,263
	Net (loss) income from operations	(3,283		)	1,758			16,233			(12,402		)	2,306
	Net (loss) income attributable to WMLP
	unitholders	(10,186		)	(2,897		)	9,787			(19,589		)	(22,885		)
	Net (loss) income allocated to general partner	(202		)	(57		)	193			(363		)	(429		)
	Net (loss) income allocated to limited partners	(9,984		)	(2,840		)	9,594			(19,226		)	(22,456		)
	(Loss) income per limited partner unit:
	Basic	$	(4.92	)	$	(1.32	)	$	4.68		$	(9.24	)	$	(10.92	)
	Diluted	$	(4.92	)	$	(1.32	)	$	4.68		$	(9.24	)	$	(10.92	)
	Distributions paid per unit:
	Limited partners:
	Common	$	—		$	—		$	—		$	—		$	—
	Subordinated	$	—		$	—		$	—		$	—		$	—
	General partner	$	—		$	—		$	—		$	—		$	—
		Oxford Resource Partners, LP
		(Predecessor)
		2013
		31-Mar			30-Jun			30-Sep			31-Dec			Total
	Total revenues	$	88,726		$	88,125		$	87,586		$	82,330		$	346,767
	Net (loss) income from operations	(3,356		)	2,434			(1,036		)	(3,972		)	(5,930		)
	Net loss attributable to WMLP unitholders	(6,547		)	(4,510		)	(5,599		)	(8,269		)	(24,925		)
	Net loss allocated to general partner	(131		)	(89		)	(112		)	(165		)	(497		)
	Net loss allocated to limited partners	(6,416		)	(4,421		)	(5,487		)	(8,104		)	(24,428		)
	Loss per limited partner unit:
	Basic	$	(3.72	)	$	(2.52	)	$	(2.64	)	$	(3.96	)	$	(12.84	)
	Diluted	$	(3.72	)	$	(2.52	)	$	(2.64	)	$	(3.96	)	$	(12.84	)
	Distributions paid per unit:
	Limited partners:
	Common	$	—		$	—		$	—		$	—		$	—
	Subordinated	$	—		$	—		$	—		$	—		$	—
	General partner	$	—		$	—		$	—		$	—		$	—

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	Purchase and Pushdown Accounting
	WCC's acquisition of our GP was accounted for using the acquisition method under ASC 805, Business Combination. Under the acquisition method, the purchase price was allocated to the underlying tangible and intangible assets acquired and liabilities assumed based on their respective fair values. The allocation of the purchase price is preliminary pending the completion of various analyses and the finalization of estimates. During the measurement period (which is not to exceed one year from the acquisition date), additional assets or liabilities may be recognized if new information is obtained about facts and circumstances that existed as of the acquisition date that, if known, would have resulted in the recognition of those assets or liabilities as of that date. The preliminary allocation may be adjusted after obtaining additional information regarding, among other things, asset valuations, liabilities assumed and revisions of previous estimates. These adjustments may be significant and will be accounted for retrospectively.
	Per ASC 805-50-25-4 (effective November 18, 2014), we, as an acquiree of WCC through our GP, have the option to apply pushdown accounting in our consolidated financial statements when an acquirer (WCC) obtained control of us. We have chosen adopt pushdown accounting and will reflect purchase accounting adjustments in our consolidated financial statement.
Cash	Cash
	Cash consists of cash held with reputable depository institutions and is stated at cost which approximates fair value. At times, such deposits may be in excess of the FDIC insurance limit. We have not experienced any losses in such accounts and believe we are not exposed to any significant credit risk relating to such amounts.
Trade Receivables	Trade Receivables
	Trade receivables are recorded at the invoiced amount and do not bear interest. The Partnership evaluates the need for an allowance for doubtful accounts based on a review of collectability.
Inventory	Inventory
	Inventory, which includes materials and supplies as well as raw coal, is stated at the lower of cost or market. Cost is determined using the average cost method. Coal inventory costs include labor, supplies, equipment, operating overhead and other related costs.
Restricted Investments and Bond Collateral	Restricted Investments and Bond Collateral
	We had restricted cash related to Harrison Resources of $3,969 as of December 31, 2013, which is included in our consolidated balance sheets as Restricted investments and bond collateral. Harrison Resources’ cash, which is deemed to be restricted due to the limitations of its use for Harrison Resources’ operations, primarily relates to funds set aside for future reclamation obligations. There are not any further restrictions on Harrison Resources' cash following the redemption of the noncontrolling interest effective October 1, 2014. See the Noncontrolling Interest section of this Note 2 and Note 15.
Exploration and Mine Development	Exploration and Mine Development
	Exploration expenditures are charged to Cost of coal revenues as incurred, including costs related to drilling and study costs incurred to convert or upgrade mineral resources to reserves.
	At existing surface mines, additional pits may be added to increase production capacity. These expansions may require significant capital to purchase or relocate equipment, build or improve existing haul roads and create the initial cut to remove overburden for new pits at existing mines. If these pits operate in a separate and distinct area of the mine, the costs associated with initially uncovering coal for production are capitalized and amortized over the life of the developed pit consistent with coal industry practices. Once production has begun, mining costs are then expensed as incurred.
	Where new pits are routinely developed as part of a contiguous mining sequence, the Partnership expenses such costs as incurred. The development of a contiguous pit typically reflects the planned progression of an existing pit, thus maintaining production levels from the same mining area utilizing the same employee group and equipment.
Property, Plant and Equipment	Property, Plant and Equipment
	Property, plant and equipment are recorded at cost or fair value as a result of purchase accounting as previously discussed. Expenditures that extend the useful lives of existing plant and equipment or increase productivity of the assets are capitalized. Maintenance and repair costs that do not extend the useful life or increase productivity of the asset are expensed as incurred. Coal reserves are recorded at cost, or at fair value originally in the case of acquired businesses and application of pushdown accounting.
	Coal reserves, mineral rights and mine development costs are depleted based upon estimated recoverable proven and probable reserves. Plant and equipment are depreciated on a straight-line basis over the assets’ estimated useful lives as follows:
		Years
	Buildings and tipple	25 - 39
	Machinery and equipment	1 - 12
	Vehicles	7-May
	Furniture and fixtures	7-Mar
	We assess the carrying value of our property, plant and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparing estimated undiscounted cash flows expected to be generated from such assets to their net book value. If net book value exceeds estimated cash flows, the asset is written down to fair value. When an asset is retired or sold, its cost and related accumulated depreciation and depletion are removed from the accounts. The difference between the net book value of the asset and proceeds on disposition is recorded as a gain or loss. Fully depreciated plant and equipment still in use are not eliminated from the accounts. Amortization of capital leases is included in Depreciation, depletion and amortization.
Advance Coal Royalties	Advanced Coal Royalties
	A portion of our reserves are leased. Advanced coal royalties are advance payments made to lessors under terms of lease agreements that are typically recoupable through an offset or credit against royalties payable on future production. We write-off advanced coal royalties when recoverability is no longer probable based on future mining plans.
Deferred Financing Costs	Deferred Financing Costs
	We capitalize costs incurred in connection with borrowings or establishment of credit facilities and issuance of debt securities. These costs are amortized as an adjustment to interest expense over the life of the borrowing or term of the credit facility using the effective interest method. These amounts are recorded in Deferred financing costs, net in the accompanying consolidated balance sheets.
Financial Instruments	Financial Instruments
	Our financial instruments include cash, accounts receivable, restricted investments and bond collateral, accounts payable, fixed rate debt and variable rate debt. In 2012, we also had an interest rate swap agreement. We do not hold or purchase financial instruments or derivative financial instruments for trading purposes.
	Our financial instruments include fixed price forward contracts for diesel fuel. Our risk management policy allows us to purchase up to 80% of our unhedged diesel fuel gallons on fixed price forward contracts. These contracts meet the normal purchases and sales exclusion and therefore are not accounted for as derivatives. These forward fuel contracts usually have a term of 1 year or less, and we take physical delivery of all the fuel supplied under these contracts except in the case of one Illinois Basin contract which was modified in connection with its cancellation.
Warrants	Warrants
	In connection with our refinancing in June 2013, certain of the second lien lenders and lender affiliates received warrants entitling them to purchase common and subordinated units under a freestanding contract. The subordinated unit warrants were canceled on December 31, 2014. Pursuant to Financial Accounting Standards Board's Codification Topic 470-20, “Debt With Conversion and Other Options” (ASC 470-20), freestanding contracts that are settled in a company’s own stock, including common and subordinated unit warrants, are to be designated as an asset, liability or equity instrument. Both the common and subordinated unit warrants were determined to be liabilities and were recorded at fair value as determined using the Black-Scholes Pricing Model. ASC 470-20 further requires that the warrants' fair value be remeasured each reporting period, with the change in fair value being reported in the consolidated statements of operations. Fair value determinations prepared using the Black-Scholes Pricing Model require assumptions related to interest rates, unit price, exercise price, term and volatilities.
Intangible Assets	Intangible Assets
	Identifiable intangible assets acquired in a business combination must be recognized and reported separately from goodwill. These intangible assets are amortized on a straight-line basis over the respective useful life of the asset. See Note 8 for further details.
Deferred Revenue
	Deferred Revenue
	Deferred revenues represent funding received upon the negotiation of contracts for coal royalty and limestone sales. These deferred revenues are recognized as deliveries of the reserved coal or limestone are made in accordance with the contracts.
Asset Retirement Obligations	Asset Retirement Obligations
	Our asset retirement obligations, or ARO, primarily consists of estimated costs to reclaim surface land and support facilities at our mines and in accordance with federal and state reclamation laws as established by each mining permit.
	We estimate ARO for final reclamation and mine closure based upon detailed engineering calculations of the amount and timing of the future costs for a third party to perform the required work. These estimates are based on projected pit configurations at the end of mining and are escalated for inflation, and then discounted at a credit adjusted risk-free rate. We record mineral rights associated with the initial recorded liability. Mineral rights are amortized based on the units of production method over the estimated recoverable, proven and probable reserves at the related mine, and the ARO is accreted to the projected settlement date. Changes in estimates could occur due to revisions of mine plans, changes in estimated costs, and changes in timing of the performance of reclamation activities. See Note 10.
Income Taxes	Income Taxes
	As a partnership, we are not a taxable entity for federal or state income tax purposes; the tax effect of our activities passes through to our unitholders. Therefore, no provision or liability for federal or state income taxes is included in our financial statements. Net income (loss) for financial statement purposes may differ significantly from taxable income (loss) reportable to our unitholders as a result of timing or permanent differences between financial reporting under US GAAP and the regulations promulgated by the Internal Revenue Service.
Revenue Recognition	Revenue Recognition
	Revenue from coal sales is recognized at the time title and risk of loss passes to the customer in accordance with the terms of the underlying sales agreements and after any contingent performance obligations have been satisfied. Coal sales prices are subject to premiums and reductions based on variations in coal quality delivered versus specifications in our coal supply contracts, but such adjustments are typically confirmed in a matter of days. Risk of loss typically transfers to the customer at the mine or dock, when the coal is loaded on the rail, barge, or truck.
	Royalty revenue relates to coal reserves which we lease to others and oil and gas rights. For the years ended 2014, 2013 and 2012, we received royalties of $0.3 million, $0.01 million and $1.5 million, respectively.
	Non-coal revenue consists primarily of clay and limestone sales, service fees, and other miscellaneous revenue. Clay and limestone sales relate to material we recover during the coal mining process and sell to third parties. Additionally service fees are earned for operating a coal unloading facility, providing river barge loading services, and hauling ash. Periodically, we recognize miscellaneous revenue related to lost coal claims that result from granting third-party right-of-way access through small portions of various mine complexes.
Below-Market Coal Sales Contracts	Below-Market Coal Sales Contracts
	Our below-market coal sales contracts were acquired through the Phoenix Coal acquisition in 2009 and represent contracts for which the prevailing market price for the specified coal was in excess of the contract price. The fair value was based on discounted cash flows resulting from the difference between the below-market contract price and the prevailing market price at the date of acquisition. The fair value adjustments are amortized into coal sales on the basis of tons shipped over the terms of the respective contracts. Amortization of these below-market contracts included in revenue was $0.1 million and $0.6 million for the years ended December 31, 2013 and 2012, respectively. The current portion of the net carrying value of our below-market coal sales contracts was reflected in our consolidated balance sheets as Other current liabilities. No such amounts remained at December 31, 2013.
Equity-Based Compensation	Equity-Based Compensation
	Equity-based compensation expense is generally measured at the grant date and recognized as expense over the vesting period of the entire award. These costs are recorded in Cost of coal revenues and Selling and administrative in the accompanying consolidated results of operations. See Note 13.
Noncontrolling Interest	Noncontrolling Interest
	Noncontrolling interest is reported as a separate component of equity. The amount of net income (loss) attributable to the noncontrolling interest is recorded in Net income (loss) attributable to noncontrolling interest in our consolidated statements of operations. See Note 15.
Earnings (Losses) Per Unit	Earnings (Losses) Per Unit
	For purposes of our earnings per unit calculation, we apply the two class method. All outstanding limited partner units and general partner units share pro rata in income (loss) allocations and distributions, but only our general partner has voting rights. Limited partner units are further segregated into common units and subordinated units.
New Accounting Standards Issued	Accounting Pronouncement Effective in the Future
	In April 2014, the FASB issued ASU 2014-8, Presentation of Financial Statements and Property, Plant and Equipment, which changes the presentation of discontinued operations on the statements of operations and other requirements for reporting discontinued operations. Under the new standard, a disposal of a component or a group of components of an entity is required to be reported in discontinued operations if the disposal represents a strategic shift that has (or will have) a major effect on an entity’s operations and financial results when the component meets the criteria to be classified as held for sale or is disposed. The amendments in this update also require additional disclosures about discontinued operations and disposal of an individually significant component of an entity that does not qualify for discontinued operations. The new guidance is effective for interim and annual periods beginning after December 15, 2014. We adopted ASU 2014-8 effective January 1, 2015.
	In May 2014, the FASB issued ASU 2014-9, Revenue From Contracts With Customers, which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The ASU is based on the principle that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration which the entity expects to be entitled to receive in exchange for those goods or services. The ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to fulfill a contract. Entities have the option of using either a full retrospective or a modified retrospective approach for the adoption of the new standard. The new guidance is effective for the interim and annual periods beginning after December 15, 2016; early adoption is not permitted. We are currently assessing the impact that this standard will have on our consolidated financial statements.
	In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements-Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern and to provide related footnote disclosures. Under GAAP, financial statements are prepared based on the presumption that the reporting organization will continue to operate as a going concern, except in limited circumstances. Financial reporting under this presumption is commonly referred to as the going concern basis of accounting. The going concern basis of accounting is critical to financial reporting because it establishes the fundamental basis for measuring and classifying assets and liabilities. Currently, GAAP lacks guidance about management’s responsibility to evaluate whether there is substantial doubt about the organization’s ability to continue as a going concern or to provide related footnote disclosures. This ASU provides guidance to an organization’s management, with principles and definitions that are intended to reduce diversity in the timing and content of disclosures that are commonly provided by organizations today in the financial statement footnotes. The new guidance is effective for the interim and annual periods beginning after December 15, 2016; early adoption is permitted for annual or interim reporting periods for which the financial statements have not previously been issued.
	In August 2014, the FASB issued ASU 2014-17, Pushdown Accounting, which allows entities the option to elect pushdown of purchase accounting each time there is a change-in-control event in which an acquirer obtains control of the acquiree. If an acquiree does not initially elect to apply pushdown accounting upon a change-in-control event, it can subsequently elect to apply pushdown accounting to its most recent change-in-control event in a later reporting period as a change in accounting principle. Once made, the election to apply pushdown accounting is irrevocable. Entities applying pushdown accounting are required to measure the individual assets and liabilities of the acquired entity based on the measurement guidance in ASC 805, including the recognition of goodwill. However, any bargain purchase gain recognized by the acquirer should not be recognized in the acquiree’s income statement, but rather as an adjustment to additional paid-in capital. Acquisition-related debt is recognized by the acquiree only if the acquired entity is required to recognize a liability for debt in accordance with other applicable guidance. See our application of ASU 2014-17 in Note 3.
Reclassifications	Reclassifications
	Certain prior-year amounts have been reclassified in our consolidated balance sheets, statements of operations and statements of cash flows as of December 31, 2013 and 2012 to conform with the financial statement line items used by our GP's parent, WCC.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Schedule of Depreciation	Plant and equipment are depreciated on a straight-line basis over the assets’ estimated useful lives as follows:
		Years
	Buildings and tipple	25 - 39
	Machinery and equipment	1 - 12
	Vehicles	7-May
	Furniture and fixtures	7-Mar
	Property, plant and equipment, net of accumulated depreciation, depletion and amortization, consisted of the following:
		Westmoreland Resource Partners, LP			Oxford Resource Partners, LP
		(Successor)			(Predecessor)
		December 31,			December 31,
		2014			2013
	Property, plant and equipment
	Land	$	4,040		$	3,016
	Mineral rights	67,675			107,651
	Total land and mineral rights	71,715			110,667
	Buildings and tipple	1,430			2,117
	Machinery and equipment	131,640			202,663
	Vehicles	527			4,522
	Furniture and fixtures	432			1,584
	Total plant and equipment	134,029			210,886
	Total gross, property, plant and equipment	205,744			321,553
	Less: accumulated depreciation, depletion and amortization	—			(177,127		)
	Net property, plant and equipment	$	205,744		$	144,426
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	The table below shows the number of units that were excluded from the calculation of diluted loss per unit because their inclusion would be anti-dilutive to the calculation:
		Year Ended December 31,
		2014		2013		2012
	Long-term incentive plan units	70,298		42,694		371

Acquisition_and_Pushdown_Accou1

Acquisition and Pushdown Accounting (Tables)	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition	A summary of the estimated purchase consideration and a preliminary allocation of the estimated purchase consideration is as follows (in millions):
	Estimated purchase consideration
	Market value of limited partners' units	$	10.8
	Cash paid	33.5
	Total consideration	$	44.3
	Estimated fair value of liabilities assumed:
	Debt	$	160.1
	Asset retirement obligations	31.7
	Other liabilities	0.2
	Warrants	2
	Total estimated fair value of liabilities assumed	194
	Total estimated purchase consideration:	$	238.3
	Preliminary allocation of estimated purchase consideration:
	Working capital	$	14.7
	Land and mineral rights	38.6
	Plant and equipment	134
	Advanced coal royalities	9.2
	Restricted investments and bond collateral	10.6
	Intangible asset	31
	Other assets	0.2
	Total preliminary allocation of estimated purchase consideration:	$	238.3

Restructuring_and_Impairment_C1

Restructuring and Impairment Charges (Tables)	12 Months Ended
	Dec. 31, 2014
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs	WCC transactions restructuring accrual activity is summarized as follows:
		Oxford Resource Partners, LP (Predecessor)				Westmoreland Resource Partners, LP
						(Successor)
		As of December 31, 2014				For the Period						As of December 31, 2014
						31-Dec-14
		Liability				Charges			Payments			Liability
	Severance and other termination costs	$	—			$	2,783		$	—		$	2,783
Schedule of Restructuring Reserve by Type of Cost	estructuring accrual activity is summarized as follows:
		Oxford Resource Partners, LP (Predecessor)
		As of December 31, 2013			Period from January 1, 2014 through December 31, 2014						As of December 31, 2014
		Liability			Charges			Payments			Liability
	Severance and other termination costs	$	404		$	(42	)	$	(362	)	$	—
	Equipment relocation costs	252			117			(369		)	—
	Total cash restructuring charges	$	656		$	75		$	(731	)	$	—
Schedule of Impairment and Restructuring Expenses Incurred and Expected To Be Incurred	The following table summarizes the total Illinois Basin restructuring and impairment charges incurred over the course of the restructuring:
		Oxford Resource Partners, LP (Predecessor)
		Charges
		Period from January 1, 2014 through December 31, 2014			Incurred Through December 31,			Total Expected
					2014			Charges
	Cash:
	Severance and other termination costs	$	(42	)	$	1,846		$	1,846
	Professional and legal fees	—			1,021			1,021
	Equipment relocation costs	117			1,161			1,161
	Coal lease termination costs	—			23			23
	Total cash restructuring charges	75			4,051			4,051
	Non-cash:
	Coal lease termination costs	—			683			683
	Asset impairment	—			12,753			12,753
	Total non-cash restructuring charges	—			13,436			13,436
	Total restructuring and impairment charges	$	75		$	17,487		$	17,487

Inventory_Tables

Inventory (Tables)	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consisted of the following:
		Westmoreland Resource Partners, LP		Oxford Resource Partners, LP
		(Successor)		(Predecessor)
		December 31,		December 31,
		2014		2013
	Coal	$	6,590	$	5,957
	Fuel inventory	1,860		1,879
	Materials and supplies	5,563		6,004
	Total	$	14,013	$	13,840

Net_Property_Plant_and_Equipme1

Net Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Net	Plant and equipment are depreciated on a straight-line basis over the assets’ estimated useful lives as follows:
		Years
	Buildings and tipple	25 - 39
	Machinery and equipment	1 - 12
	Vehicles	7-May
	Furniture and fixtures	7-Mar
	Property, plant and equipment, net of accumulated depreciation, depletion and amortization, consisted of the following:
		Westmoreland Resource Partners, LP			Oxford Resource Partners, LP
		(Successor)			(Predecessor)
		December 31,			December 31,
		2014			2013
	Property, plant and equipment
	Land	$	4,040		$	3,016
	Mineral rights	67,675			107,651
	Total land and mineral rights	71,715			110,667
	Buildings and tipple	1,430			2,117
	Machinery and equipment	131,640			202,663
	Vehicles	527			4,522
	Furniture and fixtures	432			1,584
	Total plant and equipment	134,029			210,886
	Total gross, property, plant and equipment	205,744			321,553
	Less: accumulated depreciation, depletion and amortization	—			(177,127		)
	Net property, plant and equipment	$	205,744		$	144,426
Schedule of Depreciation, Depletion and Amortization	The amounts of depreciation expense related to owned and leased fixed assets, depletion expense related to owned and leased coal reserves, amortization expense related to mine development costs within mineral rights and amortization expense related to intangible assets for the respective years are as follows:
		For the Year Ended December 31,
		2014		2013				2012
	Depreciation	$	26,663	$	30,786			$	34,276
	Depletion	5,337		4,513				4,869
	Mine development amortization	7,088		12,528				11,783
	Intangible asset amortization(1)	227		254				242
		$	39,315	$	48,081			$	51,170
	(1)See Note 8.

Operating_Leases_Tables

Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2014
Leases, Operating [Abstract]
Operating Leases of Lessee Disclosure	As of December 31, 2014, aggregate lease payments under operating leases that have initial or remaining non-cancelable lease terms in excess of one year are set forth below:
	For the years ending December 31, 2015	$	6,189
	2016	2,871
	2017	877
	2018	227
	2019	225

Intangible_Assets_Tables

Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets
		Westmoreland Resource Partners, LP (Successor)
		As of December 31, 2014
		Estimated		Cost		Accumulated		Net Carrying
		Remaining				Amortization		Value
		Life (years)
	Intangible assets
	Favorable lease agreement	15		$	31,000	$	—	$	31,000
		Oxford Resource Partners, LP (Predecessor)
		As of December 31, 2013
		Estimated		Cost		Accumulated		Net Carrying
		Remaining				Amortization		Value
		Life (years)
	Intangible assets
	Customer relationships	13		$	3,315	$	2,127	$	1,188
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	Expected amortization of intangible assets will be approximately:
	For the years ending December 31, 2015	$	2,067
	2016	2,067
	2017	2,067
	2018	2,067
	2019	2,067
	Thereafter	20,665

Other_Current_Liabilities_Tabl

Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Other Current Liabilities	Other current liabilities consisted of the following:
		Westmoreland Resource Partners, LP		Oxford Resource Partners, LP
		(Successor)		(Predecessor)
		December 31,		December 31,
		2014		2013
	Accrued interest	$	45	$	1,424
	Accrued royalties	809		1,062
	Restructuring reserve	2,783		—
	Other	370		971
	Total	$	4,007	$	3,457

Asset_Retirement_Obligation_Ta

Asset Retirement Obligation (Tables)	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Change in Asset Retirement Obligation	Activities affecting the liability for ARO for the respective years are as follows:
		Year Ended December 31,
		2014			2013
	Asset retirement obligations, January 1,	$	31,654		$	29,013
	Accretion	2,337			2,293
	Changes resulting from additional mines	5,171			3,671
	Changes due to amount and timing of reclamation	(2,480		)	5,333
	Payments	(4,997		)	(8,656		)
	Asset retirement obligations, December 31,	31,685			31,654
	Less current portion	(7,783		)	(5,996		)
	Asset retirement obligations, less current portion	$	23,902		$	25,658

LongTerm_Debt_Tables

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure Text Block [Abstract]
Schedule of Long-term Debt Instruments	Debt consisted of the following:
		Westmoreland Resource Partners, LP			Oxford Resource Partners, LP
		(Successor)			(Predecessor)
		December 31,			December 31,
		2014			2013
	First lien debt:
	Term loan	$	175,000		$	69,321
	Revolver	—			19,500
	Total first lien debt	175,000			88,821
	Second lien debt:
	Term loan	—			75,000
	Paid-in-kind interest	—			2,318
	Debt discount, net	—			(6,456		)
	Total second lien debt, net of debt discount	—			70,862
	Notes payable	35			3,593
	Total debt	175,035			163,276
	Less current portion	(6		)	(7,901		)
	Long-term debt	$	175,029		$	155,375
Schedule of Maturities of Long-term Debt	The total debt of the Partnership matures as follows:
	During the years ending December 31, 2015	$	6
	2016	29
	2017	—
	2018	175,000
		$	175,035

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Schedule of Carrying Value and Fair Value of Debt	The estimated fair value of our debt are as follows:
		Westmoreland Resource Partners, LP				Oxford Resource Partners, LP
		(Successor)				(Predecessor)
		As of December 31, 2014				As of December 31, 2013
		Carrying		Fair Value		Carrying		Fair Value
		Amount				Amount
	Fixed rate debt	$	35	$	33	$	3,593	$	3,386
	Variable rate debt	175,000		175,000		159,683		159,683
Schedule of Financial Instruments Measured on a Recurring Basis	The financial instruments measured at fair value on a recurring basis are summarized below:
		Westmoreland Resource Partners, LP (Successor)
		Fair Value Measurements as of December 31, 2014
		Quoted Prices in Active Markets for Identical Asset or Liability		Significant Other		Significant
				Observable Inputs		Unobservable
						Inputs
	Description	(Level 1)		(Level 2)		(Level 3)
	Assets:
	Restricted investments and bond collateral	$	10,621	$	—	$	—
	Liabilities:
	Warrants	—		1,981		—
		Oxford Resource Partners, LP (Predecessor)
		Fair Value Measurements as of December 31, 2013
		Quoted Prices in Active Markets for Identical Asset or Liability		Significant Other		Significant
				Observable Inputs		Unobservable
						Inputs
	Description	(Level 1)		(Level 2)		(Level 3)
	Assets:
	Restricted investments and bond collateral	$	15,177	$	—	$	—
	Liabilities:
	Warrants	—		4,599		—

LongTerm_Incentive_Plan_Tables

Long-Term Incentive Plan (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Unvested LTIP Units	The following table summarizes additional information concerning our unvested LTIP units:
		Units		Weighted
				Average
				Grant Date
				Fair Value
	Unvested balance at December 31, 2012	21,497		$	140.08
	Granted	36,583		47.79
	Issued	(9,657	)	68.93
	Surrendered	(1,824	)	163.06
	Unvested balance at December 31, 2013	46,599		81.47
	Granted	125,363		14.42
	Issued	(108,696	)	33.03
	Surrendered	(63,266	)	32.98
	Unvested balance at December 31, 2014	—		—

Earnings_Losses_Per_Unit_Table

Earnings (Losses) Per Unit (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The computation of basic and diluted earnings (losses) per unit under the two class method for limited partner units and general partner units is presented as follows:
		Westmoreland Resource Partners, LP			Oxford Resource Partners, LP
		(Successor)			(Predecessor)
		Period of			Period from			For the Year Ended December 31,
		December 31,			1-Jan-14
		2014			Through
					December 31,
					20014			2013			2012
	Limited partner units
	Average units outstanding:
	Basic	5,671,644			2,063,983			1,898,040			1,725,996
	Effect of equity-based compensation	N/A			N/A			N/A			N/A
	Diluted (1)(2)	5,671,644			2,063,983			1,898,040			1,725,996
	Net loss allocated to limited partners
	Basic	$	(4,379	)	$	(22,500	)	$	(24,470	)	$	(26,273	)
	Diluted	(4,379		)	(22,500		)	(24,470		)	(26,273		)
	Net loss per limited partner unit
	Basic	$	(0.72	)	$	(10.92	)	$	(12.84	)	$	(15.24	)
	Diluted (1)(2)	(0.72		)	(10.92		)	(12.84		)	(15.24		)
	General partner units
	Average units outstanding:
	Basic and diluted (1)(2)	35,291			35,291			35,302			35,217
	Net loss allocated to general partner
	Basic	$	(27	)	$	(385	)	$	(455	)	$	(535	)
	Diluted	(27		)	(385		)	(455		)	(535		)
	Net loss per general partner unit
	Basic	$	(0.72	)	$	(10.92	)	$	(12.84	)	$	(15.24	)
	Diluted (1)(2)	(0.72		)	(10.92		)	(12.84		)	(15.24		)
	Distributions paid per unit:
	Limited partners:
	Common	$	—		$	—		$	—		$	18.15
	Subordinated	—			—			—			7.65
	General partner	—			—			—			12.9
	(1)	Unvested LTIP units are not dilutive units for the years and periods presented herein, but could be in the future.
	(2)	Unvested LTIP units are not anti-dilutive units either. Anti-dilutive units are not used in calculating diluted average units.

Noncontrolling_Interest_Tables

Noncontrolling Interest (Tables)	12 Months Ended
	Dec. 31, 2014
Noncontrolling Interest [Abstract]
Noncontrolling Interest Roll Forward	Noncontrolling interest, which represents the 49% of Harrison Resources owned by CONSOL, consisted of the following:
		Oxford Resource Partners, LP
		(Predecessor)
		For the Year Ended December 31,
		2014			2013
	Beginning balance	$	4,969		$	3,744
	Net (loss) income	(1,270		)	1,225
	Additional paid in capital	(99		)	—
	Redemption payment	(3,600		)	—
	Ending balance	$	—		$	4,969

Concentration_of_Credit_Risk_a1

Concentration of Credit Risk and Major Customers (Tables)	12 Months Ended
	Dec. 31, 2014
Risks and Uncertainties [Abstract]
Schedule of Revenue by Major Customers by Reporting Segments	The following table shows the amount of sales to each customer (in each year where applicable, a “Major Customer”) which individually accounted for greater than 10% of sales in any of the years ended December 31, 2014, 2013 and 2012, with a portion of these sales being facilitated by coal brokers.
		Oxford Resource Partners, LP
		(Predecessor)
		Revenues for the Year Ended December 31,
	Customer	2014		2013		2012
		(in millions)
	American Electric Power	$	167.6	$	146.3	$	128.8
	First Energy	48.7		69.2		85.8
	East Kentucky Power Cooperative	42.3		41.4		56.6

Supplemental_Quarterly_Financi1

Supplemental Quarterly Financial Information - (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Summary of Unaudited Consolidated Quarterly Operating Results	A summary of our unaudited consolidated quarterly operating results in 2014 and 2013 is as follows:
		Westmoreland Resource Partners, LP
		(Successor)
		2014
		Period of December 31			Total
	Total revenues	$	—		$	—
	Net (loss) income from operations	(2,783		)	(2,783		)
	Net (loss) income attributable to WMLP unitholders	(4,406		)	(4,406		)
	Net (loss) income allocated to general partner	(28		)	(28		)
	Net (loss) income allocated to limited partners	(4,378		)	(4,378		)
	(Loss) income per limited partner unit:
	Basic	$	(0.72	)	$	(0.72	)
	Diluted	$	(0.72	)	$	(0.72	)
		Oxford Resource Partners, LP
		(Predecessor)
		For the Three Months Ended
		March 31,			June 30,			Sept. 30,			Period from October 1, 2014 through December 31,			Period from January 1, 2014 through December 31,
		2014			2014			2014			2014			2014
	Total revenues	$	78,004		$	82,001		$	94,507		$	67,751		$	322,263
	Net (loss) income from operations	(3,283		)	1,758			16,233			(12,402		)	2,306
	Net (loss) income attributable to WMLP
	unitholders	(10,186		)	(2,897		)	9,787			(19,589		)	(22,885		)
	Net (loss) income allocated to general partner	(202		)	(57		)	193			(363		)	(429		)
	Net (loss) income allocated to limited partners	(9,984		)	(2,840		)	9,594			(19,226		)	(22,456		)
	(Loss) income per limited partner unit:
	Basic	$	(4.92	)	$	(1.32	)	$	4.68		$	(9.24	)	$	(10.92	)
	Diluted	$	(4.92	)	$	(1.32	)	$	4.68		$	(9.24	)	$	(10.92	)
	Distributions paid per unit:
	Limited partners:
	Common	$	—		$	—		$	—		$	—		$	—
	Subordinated	$	—		$	—		$	—		$	—		$	—
	General partner	$	—		$	—		$	—		$	—		$	—
		Oxford Resource Partners, LP
		(Predecessor)
		2013
		31-Mar			30-Jun			30-Sep			31-Dec			Total
	Total revenues	$	88,726		$	88,125		$	87,586		$	82,330		$	346,767
	Net (loss) income from operations	(3,356		)	2,434			(1,036		)	(3,972		)	(5,930		)
	Net loss attributable to WMLP unitholders	(6,547		)	(4,510		)	(5,599		)	(8,269		)	(24,925		)
	Net loss allocated to general partner	(131		)	(89		)	(112		)	(165		)	(497		)
	Net loss allocated to limited partners	(6,416		)	(4,421		)	(5,487		)	(8,104		)	(24,428		)
	Loss per limited partner unit:
	Basic	$	(3.72	)	$	(2.52	)	$	(2.64	)	$	(3.96	)	$	(12.84	)
	Diluted	$	(3.72	)	$	(2.52	)	$	(2.64	)	$	(3.96	)	$	(12.84	)
	Distributions paid per unit:
	Limited partners:
	Common	$	—		$	—		$	—		$	—		$	—
	Subordinated	$	—		$	—		$	—		$	—		$	—
	General partner	$	—		$	—		$	—		$	—		$	—

Organization_and_Presentation_

Organization and Presentation - Acquisitions and Contributions (Details) (USD $)	0 Months Ended	12 Months Ended	0 Months Ended	60 Months Ended	72 Months Ended
	Oct. 16, 2014	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2025	Dec. 31, 2020	Mar. 03, 2015
Business Acquisition [Line Items]
Cash paid	$33,500,000
Dividends, Units, Percentage		25.00%
Westmoreland Kemmerer Fee Coal Holdings, LLC [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%	100.00%
Coal Reserves, Fee Simple		30,400,000	30,400,000
Westmoreland Kemmerer Fee Coal Holdings, LLC [Member] | Common Units [Member]
Business Acquisition [Line Items]
Kemmerer coal reserve contribution (units)		4,512,500
Successor [Member]
Business Acquisition [Line Items]
Cash paid	33,500,000
Successor [Member] | Capital Units [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Successor [Member] | Subordinated [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Successor [Member] | Warrant [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Successor [Member] | Common Units [Member]
Business Acquisition [Line Items]
Kemmerer coal reserve contribution (units)			4,512,500
Successor [Member] | Subsequent Event [Member] | Capital Units [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired						79.00%
Scenario, Forecast [Member] | Westmoreland Kemmerer Fee Coal Holdings, LLC [Member]
Business Acquisition [Line Items]
Royalty Revenue from Coal				$500,000	$1,000,000

Organization_and_Presentation_1

Organization and Presentation - Equity Restructuring of the Partnership (Details) (USD $)	0 Months Ended	12 Months Ended	1 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2014	Jan. 31, 2015
Subsequent Event [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio	12
Minimum Quarterly Distribution, Amount Per Common Unit	$0.13	$0.13
Incentive Distribution, Distribution Per Unit, Percentage, Range One	13.00%
Incentive Distribution, Distribution Per Unit, Threshold of Quarterly Distributions Over Amount Per Unit, Range One	$0.15
Incentive Distribution, Distribution Per Unit, Threshold of Quarterly Distributions up to Amount Per Unit, Range One	$0.17
Incentive Distribution, Distribution Per Unit, Percentage, Range Two	23.00%
Incentive Distribution, Distribution Per Unit, Threshold of Quarterly Distributions Over Amount Per Unit, Range One	$0.17
Incentive Distribution, Distribution Per Unit, Threshold of Quarterly Distributions up to Amount Per Unit, Range One	$0.20
Incentive Distribution, Distribution Per Unit, Percentage, Range Three	48.00%
Incentive Distribution, Distribution Per Unit, Threshold of Quarterly Distributions Over Amount Per Unit, Range Three	$0.20
Incentive Distribution Right, Period of Time Distributions May Be Suspended	18 months
Incentive Distribution Right, Period of Time Distributions May Be Suspended with Contingencies	9 months
Incentive Distribution Rights, Drop-Down Transactions, Contingency	$35
Dividends, Units, Percentage		25.00%
Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends, Stock			206,549

Organization_and_Presentation_2

Organization and Presentation - Debt Refinancing (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2014
In Millions, unless otherwise specified
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$175
First Lien Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	75
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	25
Second Lien Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	75
Line of Credit [Member] | 2014 Financing Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		295
Secured Debt [Member] | 2014 Financing Agreement [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross		175
Debt Instrument, Unused Borrowing Capacity, Amount		$120

Organization_and_Presentation_3

Organization and Presentation - Organization (Details)	0 Months Ended
	Mar. 03, 2015	Dec. 31, 2014
		T
Subsequent Event [Line Items]
Coal Reserves, Owned or Controlled		106,500,000
Coal Reserves, Leased or Subleased to Others		54,700,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest	79.10%

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative [Line Items]
Restricted Cash and Investments, Noncurrent		$3,969,000
Litigation Settlement, Amount	19,500,000
Amortization of below market coal sales contracts		100,000	600,000
Anti-dilutive units (shares)	70,298	42,694	371
Unhedged Diesel Fuel Gallons [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage	80.00%
Forward Fuel Contract [Member] | Maximum [Member]
Derivative [Line Items]
Derivative, Term of Contract	1 year
Successor [Member]
Derivative [Line Items]
Deferred revenue	0
Predecessor [Member]
Derivative [Line Items]
Deferred revenue		3,578,000
Royalty revenues	$284,000	$8,000	$1,496,000

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Property Plant and Equipment Useful Lives (Details)	12 Months Ended
	Dec. 31, 2014
Minimum [Member] | Buildings And Tipple [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	25 years
Minimum [Member] | Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	1 year
Minimum [Member] | Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Minimum [Member] | Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member] | Buildings And Tipple [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	39 years
Maximum [Member] | Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	12 years
Maximum [Member] | Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	7 years
Maximum [Member] | Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	7 years

Acquisition_and_Pushdown_Accou2

Acquisition and Pushdown Accounting - Narrative (Details) (USD $)	0 Months Ended	3 Months Ended
In Millions, unless otherwise specified	Oct. 16, 2014	Dec. 31, 2014
Business Acquisition [Line Items]
Cash paid	$33.50
Business Combination, Consideration Transferred	238.3
Total estimated fair value of liabilities assumed	194
Selling, General and Administrative Expenses [Member]
Business Acquisition [Line Items]
Selling and administrative		5.5
Successor [Member]
Business Acquisition [Line Items]
Cash paid	$33.50
Successor [Member] | Capital Units [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Successor [Member] | Subordinated [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Successor [Member] | Warrant [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%

Acquisition_and_Pushdown_Accou3

Acquisition and Pushdown Accounting - Summary of Estimated Purchase Consideration (Details) (USD $)	0 Months Ended
In Millions, unless otherwise specified	Oct. 16, 2014	Oct. 16, 2014
Business Combination, Consideration Transferred [Abstract]
Market value of limited partners' units	$10.80
Cash paid	33.5
Total consideration	44.3
Estimated fair value of liabilities assumed:
Debt	160.1	160.1
Asset retirement obligations	31.7	31.7
Other liabilities	0.2	0.2
Warrants	2	2
Total estimated fair value of liabilities assumed	194	194
Total estimated purchase consideration:	238.3
Preliminary allocation of estimated purchase consideration:
Working capital	14.7	14.7
Land and mineral rights	38.6	38.6
Plant and equipment	134	134
Advanced coal royalities	9.2	9.2
Restricted investments and bond collateral	10.6	10.6
Intangible asset	31	31
Other assets	0.2	0.2
Total preliminary allocation of estimated purchase consideration:	238.3	238.3
Successor [Member]
Business Combination, Consideration Transferred [Abstract]
Cash paid	$33.50

Restructuring_and_Impairment_C2

Restructuring and Impairment Charges - WCC Transactions Restructuring (Details) (USD $)	12 Months Ended		0 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Charges	$1,800	$2,900
Successor [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost Remaining			600	600
Successor [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Charges			2,783
Liability			2,783	2,783
Payments for Restructuring			0
Predecessor [Member]
Restructuring Cost and Reserve [Line Items]
Charges				75
Liability	656		0	0
Payments for Restructuring				-731
Predecessor [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Charges				-42
Liability	404		0	0
Payments for Restructuring				($362)

Restructuring_and_Impairment_C3

Restructuring and Impairment Charges - Narrative (Details) (USD $)	1 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	T
Restructuring Cost and Reserve [Line Items]
Amount of Coal (in US Ton)	800,000
Impairment of Long-Lived Assets to be Disposed of		$0	$0	$12,800,000
Restructuring Charges			1,800,000	2,900,000
Predecessor [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		$75,000

Restructuring_and_Impairment_C4

Restructuring and Impairment Charges - Accrual Activity (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Charges	$1,800	$2,900
Predecessor [Member]
Restructuring Cost and Reserve [Line Items]
Liability	656		0
Charges			75
Payments			-731
Predecessor [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Liability	404		0
Charges			-42
Payments			-362
Predecessor [Member] | Equipment Relocation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Liability	252		0
Charges			117
Payments			($369)

Restructuring_and_Impairment_C5

Restructuring and Impairment Charges - Schedule of Charges Incurred (Details) (USD $)	12 Months Ended			36 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2014
Cash:
Charges	$1,800	$2,900
Predecessor [Member]
Cash:
Charges			75
Restructuring and Related Cost, Cost Incurred to Date			4,051	4,051
Restructuring and Related Cost, Expected Cost			4,051	4,051
Non-cash:
Coal lease termination costs			0	683
Asset Impairment Charges			0	12,753
Total non-cash restructuring expenses			0	13,436
Restructuring, Settlement and Impairment Provisions			75	17,487
Predecessor [Member] | Employee Severance [Member]
Cash:
Charges			-42
Restructuring and Related Cost, Cost Incurred to Date			1,846	1,846
Restructuring and Related Cost, Expected Cost			1,846	1,846
Predecessor [Member] | Other Restructuring [Member]
Cash:
Charges			0
Restructuring and Related Cost, Cost Incurred to Date			1,021	1,021
Restructuring and Related Cost, Expected Cost			1,021	1,021
Predecessor [Member] | Equipment Relocation Costs [Member]
Cash:
Charges			117
Restructuring and Related Cost, Cost Incurred to Date			1,161	1,161
Restructuring and Related Cost, Expected Cost			1,161	1,161
Predecessor [Member] | Contract Termination [Member]
Cash:
Charges			0
Restructuring and Related Cost, Cost Incurred to Date			23	23
Restructuring and Related Cost, Expected Cost			23	23
Scenario, Plan [Member]
Non-cash:
Coal lease termination costs			683
Asset Impairment Charges			12,753
Total non-cash restructuring expenses			13,436
Restructuring, Settlement and Impairment Provisions			$17,487

Inventory_Details

Inventory (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Successor [Member]
Coal	$6,590
Fuel	1,860
Spare parts and supplies	5,563
Total	14,013
Predecessor [Member]
Coal		5,957
Fuel		1,879
Spare parts and supplies		6,004
Total		$13,840

Net_Property_Plant_and_Equipme2

Net Property, Plant and Equipment - Schedule (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Successor [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$205,744
Less: accumulated depreciation, depletion and amortization	0
Net property, plant and equipment	205,744
Successor [Member] | Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	4,040
Successor [Member] | Mineral Rights [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	67,675
Successor [Member] | Land and Mineral Rights [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	71,715
Successor [Member] | Buildings And Tipple [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1,430
Successor [Member] | Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	131,640
Successor [Member] | Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	527
Successor [Member] | Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	432
Successor [Member] | Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	134,029
Predecessor [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		321,553
Less: accumulated depreciation, depletion and amortization		-177,127
Net property, plant and equipment		144,426
Predecessor [Member] | Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		3,016
Predecessor [Member] | Mineral Rights [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		107,651
Predecessor [Member] | Land and Mineral Rights [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		110,667
Predecessor [Member] | Buildings And Tipple [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		2,117
Predecessor [Member] | Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		202,663
Predecessor [Member] | Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		4,522
Predecessor [Member] | Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		1,584
Predecessor [Member] | Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross		$210,886

Net_Property_Plant_and_Equipme3

Net Property, Plant and Equipment - Depreciation, Depletion and Amortization (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment, Net [Abstract]
Depreciation	$26,663	$30,786	$34,276
Depletion	5,337	4,513	4,869
Mine development amortization	7,088	12,528	11,783
Amortization of intangible assets and liabilities, net	227	254	242
Depreciation, Depletion and Amortization	$39,315	$48,081	$51,170

Net_Property_Plant_and_Equipme4

Net Property, Plant and Equipment - Narrative (Details) (USD $)	1 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Apr. 30, 2012	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
(Gain) Loss on Sale of Assets	($6.10)	($6.30)
Royalty Rights, Percentage of Net Revenue			20.00%

Operating_Leases_Narrative_Det

Operating Leases - Narrative (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	$8,835	$8,591	$7,118
Minimum [Member]
Operating Leased Assets [Line Items]
Lessee Leasing Arrangements, Operating Leases, Term of Contract	3 years
Maximum [Member]
Operating Leased Assets [Line Items]
Lessee Leasing Arrangements, Operating Leases, Term of Contract	10 years

Operating_Leases_Future_Minimu

Operating Leases - Future Minimum Payments (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Leases, Operating [Abstract]
2015	$6,189
2016	2,871
2017	877
2018	227
2019	$225

Intangible_Assets_Schedule_Det

Intangible Assets - Schedule (Details) (USD $)	0 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Successor [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$0
Successor [Member] | Off-Market Favorable Lease [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Remaining Life (years)	15 years
Cost	31,000
Accumulated Amortization	0
Net Carrying Value	31,000
Predecessor [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization		2,100
Predecessor [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Remaining Life (years)		13 years
Cost		3,315
Accumulated Amortization		2,127
Net Carrying Value		$1,188

Intangible_Assets_Amortization

Intangible Assets - Amortization (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets and liabilities, net	$227	$254	$242
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2015	2,067
2016	2,067
2017	2,067
2018	2,067
2019	2,067
Thereafter	20,665
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets and liabilities, net	$227	$254	$242

Other_Current_Liabilities_Deta

Other Current Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Successor [Member]
Other current liabilities	$4,007
Successor [Member] | Accrued Interest [Member]
Other current liabilities	45
Successor [Member] | Accrued Royalties [Member]
Other current liabilities	809
Successor [Member] | Business Restructuring Reserves [Member]
Other current liabilities	2,783
Successor [Member] | Other Current Liabilities [Member]
Other current liabilities	370
Predecessor [Member]
Other current liabilities		3,457
Predecessor [Member] | Accrued Interest [Member]
Other current liabilities		1,424
Predecessor [Member] | Accrued Royalties [Member]
Other current liabilities		1,062
Predecessor [Member] | Business Restructuring Reserves [Member]
Other current liabilities		0
Predecessor [Member] | Other Current Liabilities [Member]
Other current liabilities		$971

Asset_Retirement_Obligation_Na

Asset Retirement Obligation - Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	mine	mine
Asset Retirement Obligations [Line Items]
Asset retirement obligations	$31,685,000	$31,654,000	$29,013,000
Changes due to amount and timing of reclamation	2,700,000	9,000,000
Number of Mines Acquired During Period	5	4
Estimated Final Reclamationand Mine Closure Cost [Member]
Asset Retirement Obligations [Line Items]
Undiscounted Aggregate Mine Closure	42,400,000
Five New Mines [Member]
Asset Retirement Obligations [Line Items]
Changes due to amount and timing of reclamation	5,200,000
Four New Mines [Member]
Asset Retirement Obligations [Line Items]
Changes due to amount and timing of reclamation		3,700,000
Reclamation Work In Progress [Member]
Asset Retirement Obligations [Line Items]
Changes due to amount and timing of reclamation	100,000	4,000,000
Pond Removal And Water Treatment [Member]
Asset Retirement Obligations [Line Items]
Changes due to amount and timing of reclamation	$2,600,000	$1,300,000

Asset_Retirement_Obligation_Sc

Asset Retirement Obligation - Schedule of Activities (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation, Beginning Period	$31,654	$29,013
Accretion of asset retirement obligations	2,337	2,293
Changes resulting from additional mines	5,171	3,671
Changes due to amount and timing of reclamation	-2,480	5,333
Payments	-4,997	-8,656
Asset Retirement Obligation, Ending Period	31,685	31,654
Less current portion	-7,783	-5,996
Asset retirement obligations, less current portion	$23,902	$25,658

LongTerm_Debt_Schedule_Details

Long-Term Debt - Schedule (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Long-term Debt	$175,035
Successor [Member]
Debt Instrument [Line Items]
Long-term Debt	175,035
Debt Instrument, Unamortized Discount	0
Notes Payable	35
Long-term Debt, Current Maturities	-6
Long-term debt, less current installments	175,029
Successor [Member] | First Lien Financing Agreement [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt	175,000
Successor [Member] | First Lien Financing Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	0
Successor [Member] | Second Lien Financing Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt	0
Successor [Member] | Second Lien Financing Agreement [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt	0
Successor [Member] | Second Lien Financing Agreement [Member] | PIK Interest [Member]
Debt Instrument [Line Items]
Long-term Debt	0
Successor [Member] | First Lien Debt [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	175,000
Predecessor [Member]
Debt Instrument [Line Items]
Long-term Debt		163,276
Debt Instrument, Unamortized Discount		-6,456
Notes Payable		3,593
Long-term Debt, Current Maturities		-7,901
Long-term debt, less current installments		155,375
Predecessor [Member] | First Lien Financing Agreement [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt		69,321
Predecessor [Member] | Second Lien Financing Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt		70,862
Predecessor [Member] | Second Lien Financing Agreement [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt		75,000
Predecessor [Member] | Second Lien Financing Agreement [Member] | PIK Interest [Member]
Debt Instrument [Line Items]
Long-term Debt		2,318
Predecessor [Member] | First Lien Debt [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Long-term Line of Credit		19,500
Predecessor [Member] | First Lien Debt [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Line of Credit		$88,821

LongTerm_Debt_Credit_Facilitie

Long-Term Debt - Credit Facilities (Details) (USD $)	0 Months Ended	3 Months Ended	12 Months Ended		1 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Jun. 24, 2013
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity					$175,000,000
Stockholders' Equity Note, Stock Split, Conversion Ratio	12
Warrants						7,900,000
Warrant or Right, Number Issued During Period		3,585
Second Lien Financing Agreement [Member]
Line of Credit Facility [Line Items]
Amortization of Debt Discount (Premium)			3,000,000	1,500,000
2014 Financing Agreement [Member] | Secured Debt [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross	175,000,000	175,000,000	175,000,000
Debt Instrument, Unused Borrowing Capacity, Amount	120,000,000	120,000,000	120,000,000
Debt Instrument, Interest Rate, Fixed Portion of the Effective Rate, Percentage			8.50%
Debt Instrument, Interest Rate, Effective Percentage	9.25%	9.25%	9.25%
2014 Financing Agreement [Member] | Secured Debt [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate, Paid-in-Kind			1.00%
2014 Financing Agreement [Member] | Secured Debt [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate, Paid-in-Kind			3.00%
2014 Financing Agreement [Member] | Secured Debt [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate			0.75%
2013 Financing Agreements [Member] | Secured Debt [Member]
Line of Credit Facility [Line Items]
(Loss) gain on debt extinguishment			-1,600,000
Warrant [Member]
Line of Credit Facility [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights	0.12	0.12	$0.12
Common Units [Member]
Line of Credit Facility [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	162,972	162,972	162,972
Subordinated Units [Member]
Line of Credit Facility [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	151,182	151,182	151,182
First Lien Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity					75,000,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity					25,000,000
Second Lien Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity					75,000,000
Line of Credit Facility Option for Additional Term Loan					$10,000,000

LongTerm_Debt_2013_Financing_A

Long-Term Debt - 2013 Financing Agreements (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
First Lien Term Loan [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Periodic Payment, Principal	$1.30
Repayments of Lines of Credit	15.1	5.7
Second Lien Term Loan [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Periodic Payment, Principal	0.2
Repayments of Lines of Credit	0.4	0
Paid-in-Kind Interest	$4.60	$2.30
PIK Interest [Member] | Second Lien Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate at Period End	5.75%

LongTerm_Debt_Debt_Maturity_Ta

Long-Term Debt - Debt Maturity Table (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]
2015	$6
2016	29
2017	0
2018	175,000
Long-term Debt	$175,035

LongTerm_Debt_Deferred_Financi

Long-Term Debt - Deferred Financing Costs (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Line of Credit Facility [Line Items]
Debt Issuance Cost	$7,000,000	$9,600,000
Non-cash interest expense	4,100,000	3,200,000	2,200,000
Selling, General and Administrative Expenses [Member]
Line of Credit Facility [Line Items]
Refinancing Related Fees	700,000
Selling, General and Administrative Expenses [Member] | Previous Credit Facility [Member]
Line of Credit Facility [Line Items]
Refinancing Related Fees	$2,400,000

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Narrative (Details) (Warrant [Member], USD $)	12 Months Ended
	Dec. 31, 2014
Warrant [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Warrants, Fair Value Per Unit (in Dollars per Item)	$11.88
Fair Value Assumption, Spot Price Per Unit (in Dollars per Item)	12
Fair Value Assumption Exercise Price (dollars per share)	$0.12
Fair Value Assumptions, Expected Term	3 years 6 months
Fair Value Assumptions, Expected Volatility Rate	84.00%
Fair Value Assumptions, Risk Free Interest Rate	1.65%

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - Carrying Amounts and Fair Values of Financial Instruments (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Amount	$175,035
Successor [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Amount	175,035
Successor [Member] | Fixed Rate Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Amount	35
Fair Value	33
Successor [Member] | Variable Rate Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Amount	175,000
Fair Value	175,000
Predecessor [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Amount		163,276
Predecessor [Member] | Fixed Rate Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Amount		3,593
Fair Value		3,386
Predecessor [Member] | Variable Rate Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Amount		159,683
Fair Value		$159,683

Fair_Value_of_Financial_Instru4

Fair Value of Financial Instruments - Financial Instruments Measured at Fair Value on a Recurring Basis (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2014
In Thousands, unless otherwise specified
Predecessor [Member] | Investment Type [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Restricted investments and bond collateral	$15,177
Predecessor [Member] | Warrant [Member] | Fair Value, Inputs, Level 1 [Member]
Liabilities:
Warrants	0
Predecessor [Member] | Warrant [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities:
Warrants	4,599
Predecessor [Member] | Warrant [Member] | Fair Value, Inputs, Level 3 [Member]
Liabilities:
Warrants	0
Successor [Member] | Investment Type [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Restricted investments and bond collateral		10,621
Successor [Member] | Warrant [Member] | Fair Value, Inputs, Level 1 [Member]
Liabilities:
Warrants		0
Successor [Member] | Warrant [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities:
Warrants		1,981
Successor [Member] | Warrant [Member] | Fair Value, Inputs, Level 3 [Member]
Liabilities:
Warrants		$0

LongTerm_Incentive_Plan_Narrat

Long-Term Incentive Plan - Narrative (Details) (Restricted Stock Units (RSUs) [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Allocated Share-based Compensation Expense	$4,559,000	$1,441,000	$1,262,000
Stock Issued During Period, Value, Restricted Stock Award, Gross	$5,638,000	$963,000	$944,000

LongTerm_Incentive_Plan_Summar

Long-Term Incentive Plan - Summary of Unvested LTIP Units (Details) (Restricted Stock Units (RSUs) [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Balance	46,599	21,497
Granted	125,363	36,583
Issued	-108,696	-9,657
Surrendered	-63,266	-1,824
Balance	0	46,599
Balance (dollars per share)	$81.47	$140.08
Granted (dollars per share)	$14.42	$47.79
Issued (dollars per share)	$33.03	$68.93
Surrendered (dollars per share)	$32.98	$163.06
Balance (dollars per share)	$0	$81.47

Earnings_Losses_Per_Unit_Detai

Earnings (Losses) Per Unit (Details) (USD $)	12 Months Ended			0 Months Ended	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013
Net loss per general partner unit
Anti-dilutive units (shares)	70,298	42,694	371
Successor [Member]
Average units outstanding:
Basic (shares)				5,671,644
Diluted (shares)				5,671,644
Net loss allocated to limited partners
Basic (dollars)				($4,379)
Diluted (dollars)				-4,379
Net loss per limited partner unit
Basic (dollars per share)				($0.72)
Diluted (dollars per share)				($0.72)
Average units outstanding:
Basic and diluted (shares)				35,291
Net loss allocated to general partner
Basic (dollars)				-27
Diluted (dollars)				-27
Net loss per general partner unit
Basic (dollars per share)				($0.72)
Diluted (dollars per share)				($0.72)
Limited partners:
General partner (dollars per share)				$0
Successor [Member] | Common Units [Member]
Limited partners:
Limitеd partners (dollar per share)				$0
Successor [Member] | Subordinated Units [Member]
Limited partners:
Limitеd partners (dollar per share)				$0
Predecessor [Member]
Average units outstanding:
Basic (shares)	2,063,983	1,898,040	1,725,996
Diluted (shares)	2,063,983	1,898,040	1,725,996
Net loss allocated to limited partners
Basic (dollars)	-22,500	-24,470	-26,273
Diluted (dollars)	-22,500	-24,470	-26,273
Net loss per limited partner unit
Basic (dollars per share)	-10.92	-12.84	-15.24		($9.24)	$4.68	($1.32)	($4.92)	($3.96)	($2.64)	($2.52)	($3.72)
Diluted (dollars per share)	-10.92	-12.84	-15.24		($9.24)	$4.68	($1.32)	($4.92)	($3.96)	($2.64)	($2.52)	($3.72)
Average units outstanding:
Basic and diluted (shares)	35,291	35,302	35,217
Net loss allocated to general partner
Basic (dollars)	-385	-455	-535
Diluted (dollars)	-385	-455	-535
Net loss per general partner unit
Basic (dollars per share)	-10.92	-12.84	-15.24
Diluted (dollars per share)	-10.92	-12.84	-15.24
Limited partners:
General partner (dollars per share)	0	0	12.9		$0	$0	$0	$0	$0	$0	$0	$0
Predecessor [Member] | Common Units [Member]
Limited partners:
Limitеd partners (dollar per share)	0	0	18.15
Predecessor [Member] | Subordinated Units [Member]
Limited partners:
Limitеd partners (dollar per share)	0	0	7.65

Noncontrolling_Interest_Narrat

Noncontrolling Interest - Narrative (Details) (Harrison Resources [Member], USD $)	0 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Oct. 14, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 30, 2007
	T
Harrison Resources [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners			49.00%		49.00%
Sale of Stock, Percentage of Ownership after Transaction	100.00%
Coal Reserves, Acquired	900,000
Reserves, Unit of Measure	5,600,000
Coal Reserves	1,700,000
Redemption payment	$3,600
Equity Method Investment, Summarized Financial Information, Revenue		23,341	34,100	34,518
Restricted Cash and Investments			3,969
Equity Method Investment, Summarized Financial Information, Assets			$10,140

Noncontrolling_Interest_Roll_F

Noncontrolling Interest - Roll Forward (Details) (USD $)	12 Months Ended			0 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Oct. 14, 2014
Predecessor [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Net (loss) income	($1,270)	$1,225	$755
Additional paid in capital	-3,125
Harrison Resources [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Redemption payment				-3,600
Harrison Resources [Member] | Predecessor [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	4,969	3,744
Net (loss) income	-1,270	1,225
Additional paid in capital	-99	0
Redemption payment	-3,600	0
Ending balance	$0	$4,969

Workers_Compensation_and_Black1

Workers' Compensation and Black Lung (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Workers' Compensation and Black Lung (Details) [Line Items]
Gross Sales Price Percentage	4.40%
Deep-Mined Coal [Member]
Workers' Compensation and Black Lung (Details) [Line Items]
Excise Tax (in Dollars per Item)	1.1
Surface-Mined Coal [Member]
Workers' Compensation and Black Lung (Details) [Line Items]
Excise Tax (in Dollars per Item)	0.55
Excise Tax [Member]
Workers' Compensation and Black Lung (Details) [Line Items]
Cost of Goods Sold	$2.90	$3.20	$3.60

Retirement_Plan_Details

Retirement Plan (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Defined Contribution Plan Employer Contribution Percent	4.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$1.90

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	12 Months Ended	1 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Feb. 28, 2013	Feb. 28, 2013
			T
Loss Contingencies [Line Items]
Surety Bonds Outstanding	$34.60
Debt Instrument, Collateral Amount	9.1
Road Bonds Outstanding	0.5
Performance Bonds Outstanding	2.9
Litigation Settlement, Amount	19.5
Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	0.5
Loss Contingency, Accrual, Current	0.3
Purchase Commitment [Member]
Loss Contingencies [Line Items]
Gain (Loss) on Contract Termination		$2.10
Coal [Member]
Loss Contingencies [Line Items]
Long-term Purchase Commitment, Minimum Mass Required			400,000
Minimum [Member]
Loss Contingencies [Line Items]
Remaining Life Of Long-Term Contract	1 year
Maximum [Member]
Loss Contingencies [Line Items]
Remaining Life Of Long-Term Contract	2 years

Concentration_of_Credit_Risk_a2

Concentration of Credit Risk and Major Customers - Narrative (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Concentration Risk [Line Items]
Fair Value, Concentration of Risk, Accounts Receivable (in Dollars)	16.3	19.6
Accounts Receivable from Electric Utilities [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	72.00%	79.50%
Three Major Customers [Member] | Sales Revenue, Net [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	80.20%	74.10%	72.60%
Three Major Customers [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	78.90%	81.50%

Concentration_of_Credit_Risk_a3

Concentration of Credit Risk and Major Customers - Schedule of Revenue (Details) (Predecessor [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue, Major Customer [Line Items]
Customer Revenue	$322,263	$346,767	$373,527
American Electric Power [Member] | Sales Revenue, Net [Member]
Revenue, Major Customer [Line Items]
Customer Revenue	167,600	146,300	128,800
First Energy [Member] | Sales Revenue, Net [Member]
Revenue, Major Customer [Line Items]
Customer Revenue	48,700	69,200	85,800
East Kentucky Power Cooperative [Member] | Sales Revenue, Net [Member]
Revenue, Major Customer [Line Items]
Customer Revenue	$42,300	$41,400	$56,600

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	12 Months Ended			9 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Oct. 15, 2014
Related Party Transaction [Line Items]
Notice Period For Terminating Service Agreement	30 days
Accounts Payable, Related Parties, Current	$600,000	$600,000
Tunnell Hill [Member]
Related Party Transaction [Line Items]
Net proceeds from sales of assets		877,000
Revenue from Related Parties	600,000	400,000	200,000
Contracts Revenue	600,000	0	0
Accounts Receivable, Related Parties	0	100,000
Zanesville Aviation [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$20,000	$100,000	$100,000
Sale of Predecessor to Westmoreland Coal Company [Member] | C&T Coal, Inc. [Member]
Related Party Transaction [Line Items]
Partners' Capital, Percentage of Ownership in Partnership before Transaction				17.80%
Partners' Capital, Percentage of Ownership in General Partnership before Transaction				33.50%
Sale of Predecessor to Westmoreland Coal Company [Member] | AIM Oxford [Member]
Related Party Transaction [Line Items]
Partners' Capital, Percentage of Ownership in Partnership before Transaction				35.00%
Partners' Capital, Percentage of Ownership in General Partnership before Transaction				65.80%

Segment_Information_Details

Segment Information (Details)	12 Months Ended
	Dec. 31, 2014
	business_segment
Segment Reporting [Abstract]
Number of Operating Segments	1
Number of Operating Subsidiaries	3

Supplemental_Quarterly_Financi2

Supplemental Quarterly Financial Information - (Unaudited) - Summary of Unaudited Consolidated Quarterly Operating Results (Details) (USD $)	0 Months Ended		3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Successor [Member]
Effect of Fourth Quarter Events [Line Items]
Total revenues	$0
Net (loss) income from operations	-2,783	[1]
Net loss attributable to WMLP unitholders	-4,406	[1]
Less net loss allocated to general partner	-28	[1]
Net loss allocated to limited partners	-4,378	[1]
(Loss) income per limited partner unit:
Basic (dollars per share)	($0.72)
Diluted (dollars per share)	($0.72)
Limited partners:
General partner (dollars per share)	$0
Predecessor [Member]
Effect of Fourth Quarter Events [Line Items]
Total revenues			67,751	94,507	82,001	78,004	82,330	87,586	88,125	88,726	322,263	346,767
Net (loss) income from operations			-12,402	16,233	1,758	-3,283	-3,972	-1,036	2,434	-3,356	2,306	-5,930	-14,563
Net loss attributable to WMLP unitholders			-19,589	9,787	-2,897	-10,186	-8,269	-5,599	-4,510	-6,547	-22,885	-24,925	-26,808
Less net loss allocated to general partner			-363	193	-57	-202	-165	-112	-89	-131	-429	-497	-535
Net loss allocated to limited partners			($19,226)	$9,594	($2,840)	($9,984)	($8,104)	($5,487)	($4,421)	($6,416)	($22,456)	($24,428)	($26,273)
(Loss) income per limited partner unit:
Basic (dollars per share)			($9.24)	$4.68	($1.32)	($4.92)	($3.96)	($2.64)	($2.52)	($3.72)	($10.92)	($12.84)	($15.24)
Diluted (dollars per share)			($9.24)	$4.68	($1.32)	($4.92)	($3.96)	($2.64)	($2.52)	($3.72)	($10.92)	($12.84)	($15.24)
Limited partners:
General partner (dollars per share)			$0	$0	$0	$0	$0	$0	$0	$0	$0	$0	$12.90
Predecessor [Member] | Common Units [Member]
Limited partners:
Limitеd partners (dollar per share)			$0	$0	$0	$0	$0	$0	$0	$0	$0	$0
Predecessor [Member] | Subordinated Units [Member]
Limited partners:
Limitеd partners (dollar per share)			$0	$0	$0	$0	$0	$0	$0	$0	$0	$0
[1]	See Note 3.