WESTMORELAND COAL (WLBAQ) 10-K 14 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Mar. 09, 2016	Jun. 30, 2015
Document Documentand Entity Information [Abstract]
Entity Registrant Name	WESTMORELAND COAL Co
Entity Central Index Key	106,455
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Amendment Flag	false
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 363,374,374
Entity Common Stock, Shares Outstanding		18,307,350

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 22,936	$ 14,258
Receivables:
Trade	134,141	143,052
Loan and lease receivables	6,157	10,493
Contractual third-party reclamation receivables	8,020	12,462
Other	11,598	19,923
Total receivables	159,916	185,930
Inventories	121,858	133,855
Other current assets	16,103	13,645
Total current assets	320,813	347,688
Property, plant and equipment:
Land and mineral rights	476,447	500,226
Plant and equipment	790,677	956,112
Gross property, plant and equipment	1,267,124	1,456,338
Less accumulated depreciation, depletion and amortization	554,008	528,676
Net property, plant and equipment	713,116	927,662
Loan and lease receivables	49,313	73,180
Advanced coal royalties	19,781	17,508
Reclamation deposits	77,364	77,907
Restricted investments and bond collateral	140,807	164,389
Contractual third-party reclamation receivables, less current portion	86,915	104,021
Investment in joint venture	27,374	33,409
Intangible assets, net of accumulated amortization of $15.9 million and $15.3 million at December 31, 2015 and December 31, 2014, respectively	29,190	31,315
Other assets	37,723	39,416
Total Assets	1,502,396	1,816,495
Current liabilities:
Current installments of long-term debt	38,852	43,136
Revolving lines of credit	1,970	9,576
Accounts payable and accrued expenses:
Trade and other accrued liabilities	109,850	149,514
Interest payable	15,527	2,699
Production taxes	46,895	45,747
Postretirement medical benefits	13,855	13,263
Pension and SERP	368	368
Deferred revenue	10,715	13,175
Asset retirement obligations	43,950	43,289
Other current liabilities	30,688	53,130
Total current liabilities	312,670	373,897
Long-term debt, less current installments	1,004,892	932,075
Workers’ compensation, less current portion	5,068	6,315
Excess of black lung benefit obligation over trust assets	17,220	11,252
Postretirement medical costs, less current portion	285,518	293,156
Pension and SERP obligations, less current portion	44,808	49,779
Deferred revenue, less current portion	24,613	35,255
Asset retirement obligations, less current portion	375,813	409,456
Intangible liabilities, net of accumulated amortization of $9.8 million at December 31, 2015 and $13.5 million at December 31, 2014, respectively	3,470	4,538
Deferred income taxes	0	21,769
Other liabilities	30,208	28,448
Total liabilities	2,104,280	2,165,940
Shareholders' deficit:
Preferred stock of $1.00 par value. Authorized 5,000,000 shares; no issued and outstanding shares at December 31, 2015 and 91,669 shares issued and outstanding at December 31, 2014	0	92
Common stock of $0.01 par value as of December 31, 2015 and $2.50 par value as of December 31, 2014. Authorized 30,000,000 shares; Issued and outstanding 18,162,148 shares at December 31, 2015 and 17,102,777 shares at December 31, 2014, respectively	182	42,756
Other paid-in capital	240,721	185,644
Accumulated other comprehensive loss	(171,300)	(124,296)
Accumulated deficit	(672,219)	(468,902)
Total shareholders’ deficit	(602,616)	(364,706)
Noncontrolling interests in consolidated subsidiaries	732	15,261
Total deficit	(601,884)	(349,445)
Total Liabilities and Deficit	$ 1,502,396	$ 1,816,495

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Intangible assets, accumulated amortization	$ 13.8	$ 15.3
Intangible liabilities, accumulated amortization	$ 9.8	$ 13.5
Preferred stock, par value (in USD per share)	$ 1	$ 1
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	91,669
Preferred stock, shares outstanding	0	91,669
Common stock, par value (in USD per share)	$ 0.01	$ 2.50
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	18,162,148	17,102,777
Common stock, shares outstanding	18,162,148	17,102,777

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Revenues	$ 1,411,048,000	$ 1,115,992,000	$ 674,686,000
Cost, expenses and other:
Cost of sales	1,145,443,000	899,930,000	535,320,000
Depreciation, depletion and amortization	131,491,000	100,778,000	67,231,000
Selling and administrative	112,972,000	100,528,000	50,721,000
Heritage health benefit expenses	14,573,000	13,388,000	13,418,000
Loss (gain) on sales of assets	4,866,000	1,232,000	(74,000)
Loss on impairment	136,210,000	0	0
Restructuring charges	656,000	14,989,000	5,078,000
Derivative loss	5,587,000	31,100,000	0
Income from equity affiliates	(5,409,000)	(3,159,000)	0
Other operating loss (income)	(3,000,000)	181,000	(22,370,000)
Total costs, expenses and other	1,543,389,000	1,158,967,000	649,324,000
Operating income (loss)	(132,341,000)	(42,975,000)	25,362,000
Other income (expense):
Interest expense	(104,215,000)	(84,234,000)	(39,937,000)
Loss on extinguishment of debt	(5,385,000)	(49,154,000)	(64,000)
Interest income	7,993,000	6,400,000	1,366,000
Gain (loss) on foreign exchange	3,674,000	(4,016,000)	0
Other income	1,740,000	1,031,000	364,000
Total other income (expense)	(96,193,000)	(129,973,000)	(38,271,000)
Loss before income taxes	(228,534,000)	(172,948,000)	(12,909,000)
Income tax expense (benefit)	(19,767,000)	232,000	(4,782,000)
Net loss	(208,767,000)	(173,180,000)	(8,127,000)
Less net loss attributable to noncontrolling interest	(5,453,000)	(921,000)	(3,430,000)
Net loss attributable to the Parent company	(203,314,000)	(172,259,000)	(4,697,000)
Less preferred stock dividend requirements	3,000	859,000	1,360,000
Net loss applicable to common shareholders	$ (203,317,000)	$ (173,118,000)	$ (6,057,000)
Net loss per share applicable to common shareholders:
Basic and diluted (in dollars per share)	$ (11.36)	$ (10.86)	$ (0.42)
Weighted average number of common shares outstanding:
Basic and diluted (in shares)	17,905	15,941	14,491

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net loss allocated to noncontrolling interest	$ (208,767)	$ (173,180)	$ (8,127)
Pension and other postretirement plans:
Amortization of accumulated actuarial gains or losses, pension	1,347	983	3,490
Adjustments to accumulated actuarial losses and transition obligations, pension	160	(24,793)	28,974
Amortization of accumulated actuarial gains or losses, transition obligations, and prior service costs, postretirement medical benefits	1,308	18	4,005
Adjustments to accumulated actuarial gains, postretirement medical benefits	7,322	(19,442)	53,230
Change in foreign currency translation adjustment	(52,021)	(17,880)	0
Unrealized and realized gains and losses on available-for-sale securities	(1,738)	413	(57)
Tax effect of other comprehensive income gains	(3,382)	0	(4,892)
Other comprehensive income (loss)	(47,004)	(60,701)	84,750
Comprehensive income (loss) attributable to Westmoreland Coal Company	$ (255,771)	$ (233,881)	$ 76,623

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Deficit - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Other Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Non-controlling Interest
Beginning balance at Dec. 31, 2012	$ (286,231)	$ 160	$ 35,502	$ 130,852	$ (148,345)	$ (289,727)	$ (14,673)
Beginning balance, shares at Dec. 31, 2012		159,960	14,201,411
Preferred dividends declared	(1,360)					(1,360)
Common stock issued as compensation	5,322		$ 560	4,762
Common stock issued as compensation, shares			224,129
Issuance of restricted stock	(336)		$ 417	(753)
Issuance of restricted stock, shares			166,691
Assumption of noncontrolling interest of subsidiary	18,103						18,103
Net loss allocated to noncontrolling interest	(8,127)					(4,697)	(3,430)
Other comprehensive income (loss)	84,750				84,750
Ending balance at Dec. 31, 2013	(187,879)	$ 160	$ 36,479	134,861	(63,595)	(295,784)	0
Ending balance, shares at Dec. 31, 2013		159,960	14,592,231
Preferred dividends declared	(859)					(859)
Common stock issued as compensation	6,082		$ 116	5,966
Common stock issued as compensation, shares			47,386
Common stock options exercised	750		$ 88	662
Common stock options exercised, shares			35,000
SARs exercised	0		$ 40	(40)
SARs exercised (shares)			16,130
Conversion of convertible notes and securities	0	$ (68)	$ 1,168	(1,100)
Conversion of convertible notes and securities, shares		(68,291)	466,537
Common stock issued to pension plans assets	1,941		$ 117	1,824
Common stock issued to pension plans assets, shares			46,323
Offering shares	56,473		$ 4,211	52,262
Offering shares (shares)			1,684,507
Issuance of restricted stock	(2,846)		$ 537	(3,383)
Issuance of restricted stock, shares			214,663
Changes in WMLP ownership interest, net				(5,408)			5,408
Assumption of noncontrolling interest of subsidiary	10,774						10,774
Net loss allocated to noncontrolling interest	(173,180)					(172,259)	(921)
Other comprehensive income (loss)	(60,701)				(60,701)
Ending balance at Dec. 31, 2014	(349,445)	$ 92	$ 42,756	185,644	(124,296)	(468,902)	15,261
Ending balance, shares at Dec. 31, 2014		91,669	17,102,777
Preferred dividends declared	(3)					(3)
WMLP distributions	(797)						(797)
Common stock issued as compensation	7,748		$ 100	7,648
Common stock issued as compensation, shares			269,567
Conversion of convertible notes and securities	(319)	$ (92)	$ 1,511	(1,738)
Conversion of convertible notes and securities, shares		(91,669)	604,557
Common stock issued to pension plans assets	(3,297)		$ 408	(3,705)
Common stock issued to pension plans assets, shares			185,247
Change in WMLP ownership percentage				8,279			(8,279)
Change in par value of common stock from $2.50 to $0.01			$ (44,593)	44,593
Net loss allocated to noncontrolling interest	(208,767)					(203,314)	(5,453)
Other comprehensive income (loss)	(47,004)				(47,004)		0
Ending balance at Dec. 31, 2015	$ (601,884)	$ 0	$ 182	$ 240,721	$ (171,300)	$ (672,219)	$ 732
Ending balance, shares at Dec. 31, 2015		0	18,162,148

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net loss allocated to noncontrolling interest	$ (208,767)	$ (173,180)	$ (8,127)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion and amortization	131,491	100,778	67,231
Accretion of asset retirement obligation and receivable	28,207	21,604	12,681
Non-cash tax benefits	(3,625)	0	(4,892)
Share-based compensation	7,748	6,082	5,322
Loss (gain) on sales of assets	4,866	1,232	(74)
Non-cash interest expense	6,857	0	0
Non-cash interest expense	10,601	3,481	3,731
Loss on extinguishment of debt	4,445	49,154	64
Loss on derivative instruments	5,587	31,100	0
(Gain) loss on foreign exchange	(3,674)	4,016	0
Loss on impairment	136,210	0	0
Income from equity affiliates	(5,409)	(3,159)	0
Distributions from equity affiliates	7,057	4,042	0
Deferred income tax	(17,457)	(230)	0
Other	(2,497)	3,635	(339)
Changes in operating assets and liabilities:
Receivables	1,987	(403)	(7,636)
Inventories	2,010	45,335	(2,512)
Excess of black lung benefit obligation over trust assets	4,168	2,577	319
Accounts payable and accrued expenses	(11,016)	(37,763)	13,579
Deferred revenue	(13,094)	(12,246)	(9,078)
Income tax payable	(595)	1,674	(1)
Accrual for workers' compensation	(1,328)	(475)	(2,069)
Asset retirement obligations	(17,368)	(7,661)	(9,410)
Accrual for postretirement medical benefits	1,584	2,665	7,721
Pension and SERP obligations	(1,034)	(2,186)	2,388
Other assets and liabilities	(21,392)	10,281	11,819
Net cash provided by operating activities	45,562	50,353	80,717
Cash flows from investing activities:
Additions to property, plant and equipment	(77,921)	(50,326)	(28,591)
Change in restricted investments and bond collateral and reclamation deposits	(28,670)	(52,514)	1,434
Cash payments in escrow for future acquisitions	34,000	(34,000)	0
Cash payments related to acquisitions and other	(32,529)	(352,635)	0
Cash acquired related to acquisition, net	2,780	8,173	0
Net proceeds from sales of assets	2,224	38,740	902
Proceeds from the sale of restricted investments	15,532	8,677	8,287
Payments related to loan and lease receivables	21,954	(5,682)	0
Receipts from loan and lease receivables	(5,654)	8,039	0
Other	(2,517)	(1,244)	(3,929)
Net cash used in investing activities	(70,801)	(432,772)	(21,897)
Cash flows from financing activities:
Change in book overdrafts	2,290	141	310
Borrowings from long-term debt, net of debt discount	199,359	1,315,947	0
Repayments of long-term debt	(148,071)	(955,177)	(28,088)
Borrowings on revolving lines of credit	201,746	25,000	7,000
Repayments on revolving lines of credit	(209,351)	(15,424)	(7,000)
Debt issuance costs and other refinancing costs	(8,132)	(88,144)	(182)
Preferred dividends paid	(3)	(859)	(1,360)
Proceeds from issuance of common shares	0	56,473	0
Exercise of stock options	0	749	0
Redemption of preferred stock	(318)	0	0
Distributions to noncontrolling interests	(797)	0	0
Net cash provided by (used in) financing activities	36,723	338,706	(29,320)
Effect of exchange rate changes on cash	(2,806)	(3,139)	0
Net increase (decrease) in cash and cash equivalents	8,678	(46,852)	29,500
Cash and cash equivalents, beginning of year	14,258	61,110	31,610
Cash and cash equivalents, end of year	22,936	14,258	61,110
Supplemental disclosures of cash flow information:
Cash paid for interest	72,972	85,047	36,252
Cash paid (received) for income taxes	434	117	111
Non-cash transactions:
Accrued purchases of property and equipment	3,766	11,740	1,112
Capital leases and other financing sources	$ 15,232	$ 15,599	$ 5,371

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Operations Westmoreland Coal Company, or the Company, Westmoreland, WCC, or the Parent, is an energy company with our principal activities conducted within the United States and Canada. Our U.S. operations include the production and sale of coal from mines in Montana, North Dakota, Texas, and Ohio and the ownership of the Roanoke Valley power plants, or ROVA, in North Carolina. We also own the general partner of, and 93.8% of the total equity interest in, Westmoreland Resource Partners, LP (“WMLP”), a publicly traded limited partnership that owns and operates five coal mining complexes in Ohio and one coal mine in Wyoming. Our Canadian operations include the production and sale of coal from six surface mines in Alberta and Saskatchewan, selling char to the barbecue briquette industry, and a 50% interest in an activated carbon plant, which produces activated carbon for the removal of mercury from flue gas. Consolidation Policy The Consolidated Financial Statements of Westmoreland Coal Company include the accounts of the Company and its controlled subsidiaries. The Company provides for noncontrolling interests in consolidated subsidiaries in which the Company’s ownership is less than 100%. All intercompany accounts and transactions have been eliminated. Investments in unconsolidated affiliates that the Company has the ability to exercise significant influence over, but not control, are accounted for under the equity method of accounting. Under the equity method of accounting, the Company records its proportionate share of the entity’s net income or loss at each reporting period in Income from equity affiliates on the Consolidated Statements of Operations with a corresponding entry to increase or decrease the carrying value of the investment. The Company’s 50% interest in the Estevan Activated Carbon Joint Venture is accounted for under the equity method of accounting. Use of Estimates The preparation of financial statements in conformity with Generally Accepted Accounting Principles (“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. Cash and Cash Equivalents Cash and cash equivalents are stated at cost, which approximate fair value. Cash equivalents consist of highly liquid investments with original maturities of three months or less. Trade Receivables Trade receivables are recorded at the invoiced amount and generally do not bear interest. The Company evaluates the need for an allowance for doubtful accounts based on a review of collectability. The Company has determined that no allowance is necessary for trade receivables as of December 31, 2015 or 2014. Loan and Lease Receivables The Company periodically executes loans and finance leases at the Genesee Mine with its only customer for purposes of funding capital expenditures and working capital requirements. Finance lease and loan receivables are measured at the present value of the future lease payments at the inception of the arrangement. Lease payments received are comprised of a repayment of principal and finance income. Finance income is recognized based on the interest rate implicit in the finance lease. We recognize finance income over periods between three and twenty-seven years , which reflect a constant periodic return on our net investment in the finance lease. Initial direct costs are included in the initial measurement of the finance lease receivables and reduce the amount of income recognized over the lease term. Inventories Inventories include materials and supplies, which are carried at historical cost less an obsolescence reserve when necessary, and raw coal, which is carried at the lower of cost or market. Cost of coal is determined using the average cost method and includes labor, supplies, equipment, depreciation, depletion, amortization, operating overhead and other related costs. Exploration and Mine Development Exploration expenditures are charged to Cost of sales as incurred, including costs related to drilling and study costs incurred to convert or upgrade mineral resources to reserves. At existing surface operations, additional pits may be added to increase production capacity in order to meet customer requirements. These expansions may require significant capital to purchase additional equipment, relocate equipment, build or improve existing haul roads and create the initial pre-production box cut to remove overburden for new pits at existing operations. 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 Company 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 and includes long-term spare parts inventory. 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. Coal reserves, mineral rights and mine development costs are depleted based upon estimated recoverable proven and probable reserves. Long-term spare parts inventory begins depreciation when placed in service. Plant and equipment are depreciated on a straight-line basis over the assets’ estimated useful lives as follows: Years Buildings and improvements 5 to 40 Machinery and equipment 1 to 36 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 is not eliminated from the accounts. Amortization of capital leases is included in Depreciation, depletion and amortization . Impairment of Long-Lived Assets The Company evaluates its long-lived assets held and used in operations for impairment as events and changes in circumstances indicate that the carrying amount of such assets might not be recoverable. Factors that would indicate potential impairment to be present include, but are not limited to, a sustained history of operating or cash flow losses, an unfavorable change in earnings and cash flow outlook, prolonged adverse industry or economic trends and a significant adverse change in the extent or manner in which a long-lived asset is being used or in its physical condition. Assets are grouped at the lowest level for which there are identifiable cash flows that are largely independent of the cash flows of other groups of assets. Coal mining assets are generally grouped at the mine level, and our ROVA operations also constitute an asset group. When indicators of impairment are present, the Company evaluates its long-lived assets for recoverability by comparing the estimated undiscounted cash flows expected to be generated by those assets under various assumptions to their carrying amounts. If such undiscounted cash flows indicate that the carrying value of the asset group is not recoverable, impairment losses are measured by comparing the estimated fair value of the asset group to its carrying amount. Fair value is generally determined through the use of an expected present value technique based on the income approach. The estimated future cash flows and underlying assumptions used to assess recoverability and, if necessary, measure the fair value of the Company's long-lived asset groups are derived from those developed in connection with the Company's planning and budgeting process. Our estimated future cash flows for our ROVA asset group also utilize projected power prices in addition to the estimated cash flows developed by our planning and budgeting process. The Company believes its assumptions to be consistent with those a market participant would use for valuation purposes. Reclamation Deposits and Contractual Third-Party Reclamation Receivables Certain of the Company’s customers have either agreed to reimburse the Company for reclamation expenditures as they are incurred or have pre-funded a portion of the expected reclamation costs. Amounts received from customers and held on deposit are recorded as reclamation deposits. Amounts that are reimbursable by customers are recorded as third-party reclamation receivables when the related reclamation obligation is recorded. Financial Instruments The Company evaluates all of its financial instruments to determine if such instruments are derivatives, derivatives that qualify for the normal purchase normal sale exception or instruments that contain features that qualify them as embedded derivatives. Except for derivatives that qualify for the normal purchase normal sale exception, all derivative financial instruments are recognized in the balance sheet at fair value. Changes in fair value are recognized in earnings if they are not eligible for hedge accounting or Accumulated other comprehensive income (loss) if they qualify for cash flow hedge accounting. Held-to-maturity financial instruments consist of non-derivative financial assets with fixed or determinable payments and a fixed term, which the Company has the ability and intent to hold until maturity, and, therefore, accounts for them as held-to-maturity securities. Held-to-maturity securities are recorded at amortized cost, adjusted for the amortization or accretion of premiums or discounts calculated on the effective interest method. Interest income is recognized when earned. The Company has securities classified as available-for-sale, which are recorded at fair value. The changes in fair values are recorded as unrealized gains (losses) as a component of Accumulated other comprehensive income (loss) in shareholders’ deficit. The Company reviews its securities routinely for other-than-temporary impairment. The primary factors used to determine if an impairment charge must be recorded because a decline in value of the security is other than temporary include (i) whether the fair value of the investment is significantly below its cost basis, (ii) the financial condition of the issuer of the security, (iii) the length of time that the cost of the security has exceeded its fair value and (iv) the Company’s intent and ability to retain the investment for a period of time sufficient to allow for any anticipated recovery in market value. Other-than-temporary impairments are recorded as a component of Other income . Fair Value 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 a given measurement date. Valuation techniques used must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value and is defined as: • Level 1, defined as observable inputs such as quoted prices in active markets for identical assets. Level 1 assets include available-for-sale equity securities generally valued based on independent third-party market prices. • Level 2, defined as observable inputs other than Level 1 prices. These include quoted prices for similar assets or liabilities in an active market, quoted prices for identical assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. Intangible Assets and Liabilities Identifiable intangible assets or liabilities acquired in a business combination are recognized and reported separately from goodwill. Workers’ Compensation Benefits The Company is self-insured for workers’ compensation claims incurred prior to 1996. The liabilities for workers’ compensation claims are actuarially determined estimates of the ultimate losses incurred based on the Company’s experience. Adjustments to the actuarially determined liability are made annually based on subsequent developments and experience and are included in operations at the time of the revised estimate. The Company insures its current employees through third-party insurance providers and state arrangements. Pneumoconiosis (Black Lung) Benefits The Company is self-insured for federal and state black lung benefits for former heritage employees and has established an independent trust to pay these benefits. The Company accounts for these benefits on the accrual basis. An independent actuary annually calculates the present value of the accumulated black lung obligation. The underfunded status in 2015 and 2014 of the Company’s obligation is included as Excess of black lung benefit obligation over trust assets in the accompanying consolidated balance sheets. Actuarial gains and losses are recognized in the period in which they arise. The Company insures its current represented employees through arrangements with its unions and its current non-represented employees are insured through third-party insurance providers. The Company maintains actuarially determined accruals to account for estimates of the ultimate losses incurred. Postretirement Health Care Benefits The Company accrues the cost to provide the benefits over the employees’ period of active service for postretirement benefits other than pensions. These costs are determined on an actuarial basis. The Company’s consolidated balance sheet reflects the unfunded status of postretirement benefit obligations. Pension and SERP Plans The Company accrues the cost to provide the benefits over the employees’ period of active service for the non-contributory defined benefit pension and SERP plans it sponsors. These costs are determined on an actuarial basis. The Company’s consolidated balance sheet reflects the unfunded status of the defined benefit pension and SERP plans. Deferred Revenue Deferred revenues represent funding received in advance of meeting the criteria for revenue recognition. Deferred revenue is recognized as the underlying revenue recognition criteria are met, which often occurs as deliveries of coal or power are made in accordance with long-term contacts. Asset Retirement Obligations The Company’s asset retirement obligation, or ARO, liabilities primarily consist of estimated costs to reclaim surface land and support facilities at its mines and power plants in accordance with federal and state reclamation laws as established by each mining permit. The Company estimates its ARO liabilities 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 and are escalated for inflation, and then discounted at a credit-adjusted risk-free rate. The Company records 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 liability 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. Income Taxes The Company is subject to income taxes in the U.S. (including federal and state) and certain foreign jurisdictions. Deferred income taxes are provided for temporary differences arising from differences between the financial statement amount and tax basis of assets and liabilities existing at each balance sheet date using enacted tax rates anticipated to be in effect when the related taxes are expected to be paid or recovered. A valuation allowance is established if it is more likely than not (greater than 50%) that a deferred tax asset will not be realized. In determining the need for a valuation allowance at each reporting period, the Company considers projected realization of tax benefits based on expected levels of future taxable income, the duration of statutory carryforward periods, experience with operating loss and tax credit carryforwards not expiring and availability of tax planning strategies. Accounting guidance prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. Under this guidance, a company can recognize the benefit of an income tax position only if it is more likely than not (greater than 50%) that the tax position will be sustained upon tax examination, based solely on the technical merits of the tax position. Guidance is also provided on the derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition. The Company includes interest and penalties related to income tax matters in income tax expense. Deferred tax liabilities and assets are classified as noncurrent in the statement of financial position. The tax effect of pretax income or loss from continuing operations is generally determined by a computation that does not consider the tax effects of items that are not included in continuing operations. The exception to that incremental approach is that all items (for example, items recorded in other comprehensive income, extraordinary items, and discontinued operations) be considered in determining the amount of tax benefit that results from a loss from continuing operations and that shall be allocated to continuing operations. Deferred Financing Costs The Company capitalizes 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 Other assets in the accompanying consolidated balance sheets. Coal Revenues The Company recognizes coal sales revenue at the time title 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 revenue is recognized based on the pricing contained in the contracts in place at the time that title passes. Power Revenues ROVA supplies power it produces and generates revenues from such sales, as well as through the settlement of related purchased power arrangements. A portion of the payment under the power sales agreement is considered to be an operating lease. The Company is recognizing amounts previously invoiced as revenue on a pro rata basis over the remaining term of the power sales agreement. Other Operating Income (Loss) Other operating income in the accompanying Consolidated Results of Operations reflects income from sources other than coal or power revenues. Income from the Company’s Indian Coal Tax Credit monetization transaction is recorded as Other operating income . The Company recognizes other operating income when business interruption losses have been incurred and reimbursement is realized or realizable . Insurance proceeds are included in Net cash provided by operating activities when received. Share-Based Compensation Share-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 sales and Selling and administrative expenses in the accompanying consolidated results of operations. Earnings (Loss) per Share Basic earnings (loss) per share have been computed by dividing the net income (loss) applicable to common shareholders by the weighted average number of shares of common stock outstanding during each period. Net income (loss) applicable to common shareholders includes the adjustment for net income or loss attributable to the noncontrolling interest. Diluted earnings (loss) per share is computed by including the dilutive effect of common stock that would be issued assuming conversion or exercise of outstanding convertible notes, stock options, stock appreciation rights, restricted stock and warrants. No such items were included in the computation of diluted loss per share for the years ended 2015 , 2014 or 2013 because the Company incurred a loss from operations in each of these periods and the effect of inclusion would have been anti-dilutive. The table below shows the number of shares that were excluded from the calculation of diluted loss per share because their inclusion would be anti-dilutive to the calculation: Years Ended December 31, 2015 2014 2013 (In thousands) Convertible notes and securities — 626 1,093 Restricted stock units, stock options, and SARs 482 537 805 Total shares excluded from diluted shares calculation 482 1,163 1,898 Derivatives The Company enters into financial derivatives to manage exposure to fluctuations in foreign currency exchange rates and power prices. The Company does not utilize derivative financial instruments for trading purposes or for speculative purposes. The Company’s derivative instruments are recorded at fair value with changes in fair value recognized in the Consolidated Statements of Operations at the end of each period in Gain (loss) on foreign exchange or Derivative loss . Foreign Exchange Transactions Amounts held and transactions denominated in foreign currencies other than the operating unit’s functional currency give rise to foreign exchange gains and losses which are included within Gain (loss) on foreign exchange . Foreign Currency Translation The functional currency of the Company’s Canadian operations is the Canadian dollar. The Company’s Canadian operations’ assets and liabilities are translated at period end exchange rates, and revenues and costs are translated using average exchange rates for the period. Foreign currency translation adjustments are reported in Other comprehensive income (loss) . Reclassifications Certain amounts in prior periods have been reclassified to conform with the presentation of 2015 , with no effect on previously reported net loss, cash flows or shareholders’ deficit. Recently Adopted Accounting Pronouncements In September 2015, the Financial Accounting Standards Board, or FASB, issued Accounting Standard Update (“ASU”) 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments. ASU 2015-16 eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. Instead, an acquirer will recognize a measurement-period adjustment during the period in which it determines the amount of the adjustment. The guidance is effective for public business entities for fiscal years beginning after 15 December 2015, and interim periods within those fiscal years. Early adoption is permitted. We early adopted this guidance during 2015, with no material impact to our financial statements. In November 2015, the FASB issued ASU 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes. ASU 2015-17 simplifies the presentation of deferred income taxes by requiring that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. The guidance is effective for financial statements issued for annual periods beginning after December 15, 2016, and interim periods within those annual periods with early adoption permitted. We elected to early adopt this standard on December 31, 2015 and retrospectively apply the guidance to prior periods to allow for better comparison. This change in accounting principle had the effect of reducing the non-current liability Deferred income taxes by $13.1 million and $5.4 million as of December 31, 2014 and 2013, respectively. The current asset Deferred income taxes was also reduced to zero for each year by the same amounts. Accounting Pronouncements Effective in the Future In May 2014, the FASB issued ASU 2014-09, 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. In April 2015, the FASB agreed to propose a one-year deferral of the revenue recognition standard's effective date. The new guidance is now effective for the interim and annual periods beginning after December 15, 2017; early application is permitted, but not before the original effective date (annual reporting periods beginning after December 15, 2016). We are currently assessing the impact that this standard will have on our consolidated financial statements and plan to adopt the guidance by its effective date. 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. 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. We anticipate expanded going concern related disclosures to address this guidance in the year it becomes effective. In April 2015, the FASB issued ASU 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs, which requires that debt issuance costs related to a recognized liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The new guidance should be applied on a retrospective basis and is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years, with early adoption permitted. Management projects the impact to the financial statements resulting in balance sheet reclassification reducing the Long-term debt, less current installments balance for each of the respective periods upon adoption. In April 2015, the FASB issued ASU 2015-05, Internal-Use Software (Subtopic 350-40): Customer's Accounting for Fees Paid in a Cloud Computing Arrangement, which provides guidance for determining whether a cloud computing arrangement (also referred to as a hosting arrangement) has a software license element and provides guidance on the appropriate accounting treatment. The new guidance should be applied on a retrospective basis. The new guidance is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the effect that adopting this new accounting guidance will have on its consolidated results of operations, cash flows and financial position and does not believe its impact will be material. In February 2016, the FASB issued ASU No. 2016-02, "Leases" (Topic 842) ("ASU 2016-02"). The amendments in ASU 2016-02 require companies that lease assets to recognize on their balance sheets the assets and liabilities for the rights and obligations generated by contracts longer than one year. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018 with early adoption permitted. The guidance is required to be applied by the modified retrospective transition approach. Early adoption is permitted. We are currently evaluating the potential impact adopting ASU 2016-02 will have on our consolidated financial statements and footnote disclosures.

ACQUISITIONS

ACQUISITIONS	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
ACQUISITIONS	2. ACQUISITIONS Acquisition of Buckingham Coal Company, LLC On January 1, 2015, Westmoreland completed the acquisition of Buckingham Coal Company, LLC, an Ohio-based coal supplier (“Buckingham”), pursuant to an agreement dated January 1, 2015 among WCC Land Holding Company, Inc., an affiliate of the Company, for a total cash purchase price of $32.5 million (the “Buckingham Acquisition”). The Buckingham Acquisition has been accounted for 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. Of the total purchase price, $26.8 million was allocated to property plant and equipment, $12.1 million to land and mineral reserves and $6.4 million to net liabilities assumed. The Buckingham operations are included in the Company’s Coal - U.S. segment. Purchase price accounting was considered final as of December 31, 2015. Acquisition of General Partner of Westmoreland Resource Partners, LP On December 31, 2014, the Company completed the acquisition of Oxford Resources GP, LLC, the general partner of Oxford Resource Partners, LP, for $33.5 million in cash consideration (the “GP Acquisition”). Also on December 31, 2014 the Company completed a contribution of certain royalty-bearing coal reserves in return for 4,512,500 common units of Oxford Resource Partners, LP (the “Contribution”). In connection with these transactions, Oxford Resources GP, LLC was renamed to Westmoreland Resources GP, LLC, and Oxford Resource Partners, LP was renamed to Westmoreland Resource Partners, LP (“WMLP”). WMLP will continue to operate as a standalone, publicly traded master limited partnership, with common units trading on the NYSE under the symbol WMLP. The completion of the GP Acquisition and the Contribution provide Westmoreland with a platform to implement a value-creating drop-down strategy, pursuant to which it intends to periodically contribute certain U.S. and Canadian coal assets to WMLP in exchange for a combination of cash and additional limited partner interests. After completion of the GP Acquisition and the Contribution, the Company owned approximately 79% of the fully diluted limited partner interests as of December 31, 2014 which increased by December 31, 2015 to 93.8% as a result of the Kemmerer Drop, described below. WMLP resumed quarterly distributions of $0.20 per unit beginning in April 2015. In addition to receiving our proportionate share of these distributions, as WMLP's general partner, the Company is entitled to incentive distribution rights. Acquisition related costs of $0.3 million and $4.5 million have been expensed for the years ended December 31, 2015 and 2014 which are included in Selling and administrative costs. The acquisition of the GP has been accounted for 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. The Company has finalized the purchase price allocation for the GP acquisition, summarized as follows (in millions): Purchase Price: Final as of December 31, 2015 Cash paid at closing $ 30.0 Contingent consideration 3.5 Fair value of outstanding WMLP units 10.8 Total purchase consideration $ 44.3 Allocation of purchase price: Assets: Trade receivables and other $ 22.5 Inventories - materials and supplies 7.4 Inventories - coal 6.6 Other current assets 1.3 Total current assets 37.8 Land and mineral rights 40.2 Plant and equipment 134.0 Advanced coal royalties 9.2 Restricted investments and bond collateral 10.6 Intangible assets 31.0 Other assets 0.2 Total Assets 263.0 Liabilities: Trade payables and other accrued liabilities (19.1 ) Asset retirement obligations (7.8 ) Other current liabilities (4.0 ) Total current liabilities (30.9 ) Long-term debt, less current installments (160.1 ) Asset retirement obligations, less current portion (23.9 ) Warrants (2.0 ) Other liabilities (1.8 ) Total Liabilities (218.7 ) Net Assets 44.3 Non-controlling Interest (10.8 ) Invested Equity $ 33.5 No goodwill was recorded in the acquisition and a $31.0 million intangible asset related to a favorable terminal lease at a dock in Ohio will be amortized over a fifteen -year period. The favorable lease was valued based on the difference between contracted prices and market prices. Kemmerer Drop On August 1, 2015, we contributed 100% of the outstanding equity interests in Westmoreland Kemmerer, LLC (“Kemmerer”) to WMLP in exchange for $230 million in aggregate consideration, comprised of $115 million in cash and $115 million in newly issued WMLP Series A Convertible Units (the “Series A Units” and such transaction, the “Kemmerer Drop”). In connection with the Kemmerer Drop, all employees of Kemmerer and related employee liabilities, including but not limited to post-retirement pension obligations and post-retirement health benefits, were transferred to us. The Series A Units are convertible into common units representing limited partner interests of WMLP (“Common Units”), on a one -for-one basis, upon the earlier of (i) the date on which WMLP first makes a regular quarterly cash distribution to holders of Common Units in an amount equal to at least $0.22 per Common Unit, or (ii) a change of control of WMLP. Following the Kemmerer Drop, we hold an approximately 93.8% controlling interest in WMLP (on a fully diluted basis). The Kemmerer Drop represents a reorganization of entities under common control. Accordingly, the net assets transferred are deemed to have transferred at the $102.6 million carrying value as of the date of transfer. No gain or loss was recognized. Canadian Acquisition On April 28, 2014, the Company acquired Sherritt International Corporation’s coal mining operations (the “Canadian Acquisition”) which include six producing thermal coal mines in the Canadian provinces of Alberta and Saskatchewan, a char production facility, and a 50% interest in an activated carbon plant. The purchase consideration included a $282.8 million initial cash payment made on April 28, 2014, a cash payment for a working capital adjustment of $39.8 million made on June 25, 2014, and assumed liabilities of $421.3 million . Acquisition related costs of $33.6 million have been expensed for the year ended December 31, 2014 which included a $14.2 million charge to Cost of sales related to the post-close sale of inventory written up to fair value in the acquisition, $8.3 million of expenses included in Selling and administrative costs, $6.2 million of loss on foreign exchange and $4.9 million included in Interest expense related to a bridge facility commitment fee. The Canadian Acquisition has been accounted for 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. The Company has finalized the purchase price allocation for the Canadian Acquisition, summarized as follows (in millions): Purchase Price: Final as of December 31, 2014 Cash paid - Initial payment $ 282.8 Cash paid - Working capital adjustment 39.8 Total cash consideration $ 322.6 Allocation of purchase price: Assets: Cash and cash equivalents $ 26.2 Receivables 78.1 Inventories - materials and supplies 52.0 Inventories - coal 79.8 Loan and lease receivables 11.2 Deferred tax assets 8.2 Other current assets 3.4 Total current assets 258.9 Land and mineral rights 202.6 Plant and equipment 114.8 Loan and lease receivables 79.1 Contractual third-party reclamation receivables, less current portion 6.8 Investment in joint venture 36.0 Intangible assets 37.0 Other assets 8.7 Total Assets 743.9 Liabilities: Current installments of long-term debt (36.3 ) Trade payables and other accrued liabilities (136.1 ) Asset retirement obligations (7.8 ) Total current liabilities (180.2 ) Long-term debt, less current installments (86.3 ) Asset retirement obligations, less current portion (122.9 ) Deferred tax liabilities (31.9 ) Total Liabilities (421.3 ) Net fair value $ 322.6 The $26.2 million of cash and cash equivalents noted above includes $18.1 million which was used for immediate payment of an assumed liability on the acquisition date, leaving $8.1 million of net cash received upon the acquisition. During the third quarter of 2014, the Company transferred to an unrelated third party the contract related to the $37.0 million intangible asset noted above. Proceeds of $37.0 million were received from the unrelated third party, with no gain or loss recognized on the transaction. As part of the Canadian Acquisition the Company became responsible for remediation work for a breach on a containment pond at a currently inactive mine that occurred on October 31, 2013. Sherritt has indemnified Westmoreland against past and future liability stemming from the incident. Accordingly, an indemnification asset of $27.9 million and a corresponding liability was recorded at April 28, 2014. The results of the acquired operations subsequent to April 28, 2014 have been included in the Company’s consolidated results of operations. Unaudited Pro Forma Information The following unaudited pro forma information has been prepared for illustrative purposes only and assumes the acquisition of the GP and the Canadian Acquisition occurred on January 1, 2013. The unaudited pro forma results have been prepared based on estimates and assumptions, which the Company believes are reasonable, however, they are not necessarily indicative of the consolidated results of operations had the acquisitions occurred on January 1, 2013, or of future results of operations. Unaudited pro forma information for 2015 is not presented as a result of all acquired entities being consolidated for the entire year. Year Ended December 31, 2014 2013 (In thousands) Total Revenues As reported $ 1,115,992 $ 674,686 Pro forma (unaudited) $ 1,644,474 $ 1,673,538 Operating Income (Loss) As reported $ (42,975 ) $ 25,362 Pro forma (unaudited) $ (38,827 ) $ 36,097 Net loss applicable to common shareholders As reported $ (173,118 ) $ (6,057 ) Pro forma (unaudited) $ (135,647 ) $ (62,595 ) Net loss per share applicable to common shareholders As reported $ (10.86 ) $ (0.42 ) Pro forma (unaudited) $ (8.51 ) $ (4.32 )

LOSS ON IMPAIRMENT

LOSS ON IMPAIRMENT	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
LOSS ON IMPAIRMENT	3. LOSS ON IMPAIRMENT During the fourth quarter of 2015 we evaluated our ROVA asset group for impairment primarily as a result of an impairment indicator related to the continued decline in forecasted electricity prices. The asset group is comprised of property, plant, and equipment and related capital spares used to generate electricity, and resides in our Power segment. Our evaluation concluded that the long-lived assets at ROVA were impaired, and the carrying value of those assets was written down to zero as a result of an impairment charge of $133.1 million , with the charge included in the Loss on Impairment line item on the Consolidated Statement of Operations for the year ended December 31, 2015 . Our fair value measurement for these assets was determined based on a probability-weighted estimate of discounted future cash flows, which are Level 3 fair value measurements. Key inputs to the fair value measurement for these assets included current forecasted electricity prices in the region ROVA serves, which we believe will continue to remain at depressed levels, as well as forecasted cost inputs based on the Company’s planning and budgeting process. We also recorded an impairment charge of $3.1 million to the same line item on the Consolidated Statement of Operations during the year ended December 31, 2015 for certain immovable fixed assets at our Coal Valley mine, which is part of the Coal-Canada segment, primarily as a result of continued declines in pricing in the export markets which Coal Valley serves.

INVENTORIES

INVENTORIES	12 Months Ended
	Dec. 31, 2015
Inventory Disclosure [Abstract]
INVENTORIES	4. INVENTORIES Inventories consisted of the following: December 31, 2015 2014 (In thousands) Coal stockpiles $ 38,636 $ 41,795 Coal fuel inventories 7,194 6,531 Materials and supplies 78,784 88,584 Reserve for obsolete inventory (2,756 ) (3,055 ) Total $ 121,858 $ 133,855

RESTRICTED INVESTMENTS AND BOND

RESTRICTED INVESTMENTS AND BOND COLLATERAL	12 Months Ended
	Dec. 31, 2015
Disclosure Restricted Investments and Bond Collateral [Abstract]
RESTRICTED INVESTMENTS AND BOND COLLATERAL	5. RESTRICTED INVESTMENTS AND BOND COLLATERAL The Company’s restricted investments and bond collateral consist of the following: December 31, 2015 2014 (In thousands) Coal - U.S. Segment: Reclamation bond collateral: Absaloka Mine $ 11,810 $ 11,781 Colstrip Mine 3,145 3,145 Beulah Mine 1,270 1,270 Buckingham acquisition escrow — 34,000 Coal - Canada Segment: Reclamation bond collateral - PMRU 18,228 18,199 Reclamation bond collateral - CVRI 33,872 31,866 Coal - WMLP Segment: Reclamation bond collateral - Ohio 6,895 10,634 Reclamation bond collateral - Kemmerer Mine 27,631 25,282 Power Segment: Power contract collateral 22,200 12,600 Corporate Segment: Postretirement medical benefit bond collateral 8,897 8,780 Workers’ compensation bond collateral 6,856 6,832 Total restricted investments and bond collateral $ 140,804 $ 164,389 Coal Segments The coal segments maintain government-required bond collateral of individual mines which assures that coal-mining operations comply with applicable federal and state regulations relating to the performance and completion of final reclamation activities. The amounts deposited in the bond collateral account secure the bonds issued by the bonding company. Power Segment The power segment is required to maintain a collateral account related to its contracts to purchase power. Corporate Segment The Company is required to obtain surety bonds in connection with its self-insured workers’ compensation plan and certain health care plans. The Company’s surety bond underwriters require collateral to issue these bonds. Funds in the restricted investments and bond collateral accounts are not available to meet the Company’s general cash needs. The Company can invest its restricted investments and bond collateral in a limited selection of fixed-income investment options and receive the related investment returns. These accounts include available-for-sale securities. Available-for-sale securities are reported at fair value with unrealized gains and losses excluded from earnings and reported in Accumulated other comprehensive loss . On disposal, the cost basis of an investment sold is specifically identified, and the resulting gain or loss is reported in Other income . The Company’s carrying value and estimated fair value of its restricted investments and bond collateral at December 31, 2015 are as follows: Carrying Value Fair Value (In thousands) Cash and cash equivalents $ 102,536 $ 102,536 Time deposits 2,455 2,455 Available-for-sale 35,813 35,813 $ 140,804 $ 140,804 Available-for-Sale Restricted Investments and Bond Collateral Available-for-sale restricted investments and bond collateral were as follows: December 31, 2015 2014 (In thousands) Cost basis $ 36,715 $ 33,879 Gross unrealized holding gains 167 761 Gross unrealized holding losses (1,069 ) (583 ) Fair value $ 35,813 $ 34,057 Maturities of available-for-sale securities were as follows at December 31, 2015 : Amortized Cost Fair Value (In thousands) Due within one year $ 1,127 $ 1,057 Due in five years or less 15,522 14,896 Due after five years to ten years 5,142 4,939 Due in more than ten years 14,924 14,921 $ 36,715 $ 35,813 In 2015 , 2014 , and 2013 , the Company recorded gains of $0.1 million , $0.3 million , and less than $0.1 million , respectively, on the sale of available-for-sale securities held as restricted investments and bond collateral.

INTANGIBLE ASSETS AND LIABILITI

INTANGIBLE ASSETS AND LIABILITIES	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS AND LIABILITIES	6. INTANGIBLE ASSETS AND LIABILITIES Our intangible assets resulted from our acquisition, as part of a business combination, of contracts with terms that are favorable to prevailing market prices at the time of acquisition. Amortization of intangible assets recognized in Cost of sales was zero in 2015 , $1.2 million in 2014 and $1.7 million in 2013 . Our intangible liabilities resulted from our acquisition, as part of a business combination, of contracts with terms that are unfavorable to prevailing market prices at the time of acquisition. Amortization of intangible liabilities recognized in Revenues was $1.0 million in 2015 , 2014 , and 2013 . The intangible assets and liabilities are generally amortized straight-line over the life of the related contract. The estimated amortization amounts from intangibles assets and liabilities for each of the next five years as of December 31, 2015 are as follows: Amount of Amortization to Recognize in Revenues Amount of Amortization to Recognize in Cost of Sales (In thousands) 2016 $ 1,068 $ 2,130 2017 1,068 2,130 2018 1,068 2,130 2019 267 2,105 2020 — 2,096

RESTRUCTURING CHARGES RESTRUCTU

RESTRUCTURING CHARGES RESTRUCTURING CHARGES	12 Months Ended
	Dec. 31, 2015
Restructuring and Related Activities [Abstract]
RESTRUCTURING CHARGES	7. RESTRUCTURING CHARGES In 2013, the Company entered into an agreement with Virginia Power to renegotiate the remaining five years of the ROVA contract (the “ROVA Restructuring Plan”). Total restructuring charges related to the ROVA Restructuring Plan were $5.5 million and all were recorded to the restructuring expense line item within our consolidated statements of operations as they were incurred. Restructuring expenses related to the ROVA Restructuring Plan impacted our Power Segment and all actions related to this restructuring plan have been completed. During 2014, the Company initiated strategic changes related to the Canadian Acquisition and the GP Acquisition (collectively, the “Acquisition Restructuring Plans”). Total expected restructuring charges related to the Acquisition Restructuring Plans of $15.2 million have been recorded to the restructuring expense line item within our consolidated statements of operations as they were incurred. Charges related to the Acquisition Restructuring Plans were comprised of one-time employee termination benefits and impacted all segments except for our Power Segment. The table below represents the restructuring provision activity related to the restructuring plans (in millions): ROVA Restructuring Plan Acquisition Restructuring Plans Total Balance, December 31, 2013 $ 5.1 $ — $ 5.1 Restructuring Charges 0.5 14.5 15.0 Cash Payments (5.2 ) (5.7 ) (10.9 ) Balance, December 31, 2014 0.4 8.8 9.2 Restructuring Charges — 0.7 0.7 Cash Payments (0.4 ) (8.6 ) (9.0 ) Balance, December 31, 2015 $ — $ 0.9 $ 0.9

LINES OF CREDIT AND LONG-TERM D

LINES OF CREDIT AND LONG-TERM DEBT	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
LINES OF CREDIT AND LONG-TERM DEBT	8. LINES OF CREDIT AND LONG-TERM DEBT The amounts outstanding under the Company’s long-term debt consisted of the following as of the dates indicated: Total Debt Outstanding December 31, 2015 2014 (In thousands) 8.75% Notes $ 350,000 $ 350,000 WCC Term Loan Facility 327,172 350,000 WMLP Term Loan Facility 299,248 175,000 Capital lease obligations 71,168 109,351 Revolving line of credit 1,970 9,576 Other 7,251 4,062 Debt discount (11,095 ) (13,202 ) Total debt outstanding 1,045,714 984,787 Less current installments (40,822 ) (52,712 ) Total debt outstanding, less current installments $ 1,004,892 $ 932,075 The following table presents aggregate contractual debt maturities of all long-term debt: As of December 31, 2015 (In thousands) 2016 $ 40,822 2017 31,846 2018 11,094 2019 307,733 2020 315,314 Thereafter 350,000 Total 1,056,809 Less: debt discount (11,095 ) Total debt $ 1,045,714 8.75% Notes due 2022 (the “ 8.75% Notes ”) On December 16, 2014 (the “Closing Date”), the Company completed the issuance of $350.0 million in aggregate principal amount of 8.75% Notes . The 8.75% Notes were issued at a 1.292% discount, mature on January 1, 2022, and bear a fixed interest rate of 8.75% payable semiannually, on January 1 and July 1 of each year, commencing July 1, 2015. The 8.75% Notes are the Company’s senior secured obligations, rank equally in right of payment with all of the Company’s existing and future senior obligations, including the WCC Term Loan Facility defined below under “ WCC Term Loan Facility ,” and rank senior to all of the Company’s existing and future indebtedness that is expressly subordinated to the 8.75% Notes . The 8.75% Notes have not been registered under the Securities Act of 1933. In 2014, the Company capitalized debt issuance costs of $10.2 million in connection with the 8.75% Notes . The Company may redeem all or part of the 8.75% Notes beginning on January 1, 2018 at the redemption prices set forth in the 8.75% Notes agreement, and prior to January 1, 2018 at 100% of the principal amount plus the applicable premium described in the 8.75% Notes agreement. In addition, at any time prior to January 1, 2018, the Company may redeem up to 35% of the aggregate principal amount of the 8.75% Notes with the net cash proceeds of certain equity offerings at a redemption price equal to 108.75% of the principal amount to be redeemed, together with accrued and unpaid interest, if any, to the redemption date, subject to certain conditions. The 8.75% Notes are guaranteed by Westmoreland Energy LLC, Westmoreland Mining LLC and Westmoreland Resources, Inc. and their respective subsidiaries (other than Absaloka Coal, LLC, Westmoreland Risk Management, Inc. and certain other immaterial subsidiaries). The 8.75% Notes are not guaranteed by Westmoreland Canada LLC or any of its subsidiaries, nor are they guaranteed by Westmoreland Resources GP, LLC or Westmoreland Resource Partners, LP or any of its subsidiaries, referred to as the Non-guarantors. The 8.75% Notes and the guarantees are secured equally and ratably with the WCC Term Loan Facility (i) by first priority liens on substantially all of the Company’s and the guarantor parties’ tangible and intangible assets (excluding certain equity interests, mineral rights and sales contracts and certain assets subject to existing liens) and (ii) subject to the WCC Revolving Credit Facility (as defined below), a second priority lien on substantially all cash, accounts receivable and inventory of the Company and the guarantors, and any other property with respect to, evidencing or relating to such cash, accounts receivable and inventory (whether now owned or hereinafter arising or acquired) and the proceeds and products thereof, subject in each case to permitted liens and certain exclusions (the “Notes Collateral”). The Notes Collateral is shared equally with the lenders under the WCC Term Loan Facility , who hold identical first and second priority liens, as applicable, on the Notes Collateral. The 8.75% Notes restrict the Company’s and its restricted subsidiaries’ ability to, among other things, (i) incur, assume or guarantee additional indebtedness or issue preferred stock; (ii) declare or pay dividends on, or make other distributions in respect of, their capital stock; (iii) purchase or redeem or otherwise acquire for value any capital stock or subordinated indebtedness; (iv) make investments, other than permitted investments; (v) create certain liens or use assets as security; (vi) enter into agreements restricting the ability of any restricted subsidiary to pay dividends, make loans, or any other distributions to the Company or other restricted subsidiaries; (vii) engage in transactions with affiliates; and (viii) consolidate or merge with or into other companies or transfer all or substantially all of their assets. The 8.75% Notes contains, among other provisions, events of default and various affirmative and negative covenants. As of December 31, 2015 , the Company was in compliance with all covenants for the 8.75% Notes . WCC Term Loan Facility due 2020 Effective as of the Closing Date, the Company entered into a WCC Term Loan Facility which provided for a $350.0 million term loan facility with a single advance made on the Closing Date. The WCC Term Loan Facility was issued at a 2.5% discount and matures on December 16, 2020. Borrowings under the WCC Term Loan Facility initially bear interest at one-month London Interbank Offered Rate (“LIBOR”) plus 6.50% . The interest rate at December 31, 2015 was 7.50% . In 2014, the Company capitalized debt issuance costs of $8.4 million in connection with the WCC Term Loan Facility . The WCC Term Loan Facility contains customary affirmative covenants, negative covenants, and events of default. Pursuant to the terms and provisions of the Guaranty and Collateral Agreement, dated the Closing Date, the obligations under the WCC Term Loan Facility are secured by identical first and second priority liens, as applicable, on the Notes Collateral. As of December 31, 2015 , the Company was in compliance with all covenants for the WCC Term Loan Facility . The WCC Term Loan Facility is guaranteed by Westmoreland Energy LLC, Westmoreland Mining LLC, Westmoreland Resources, Inc. and certain other direct and indirect subsidiaries of the Company (other than Absaloka Coal, LLC, Westmoreland Risk Management, Inc., Westmoreland Canada, LLC, Westmoreland Resources GP, LLC, Westmoreland Resource Partners, LP and certain other immaterial subsidiaries). WCC Term Loan Facility Add-on On January 22, 2015, the Company amended the WCC Term Loan Facility to increase the borrowings by $75.0 million , for an aggregate principal amount of $425.0 million as of that date. The amendments to the WCC Term Loan Facility were made in connection with the acquisition of Buckingham Coal Company, LLC. Net proceeds were $71.0 million after a 2.5% discount, 1.5% broker fee, a consent fee of 1.17% , and $0.1 million of additional debt issuance costs. In conjunction with the Kemmerer Drop, the Company amended the WCC Term Loan Facility to remove Kemmerer as a guarantor. In addition, $94.1 million of the proceeds received from WMLP related to the Kemmerer Drop were used to pay down the WCC Term Loan Facility . WMLP Term Loan Facility due 2018 On December 31, 2014, WMLP entered into a WMLP Term Loan Facility which consists of a $175.0 million term loan, with an option for an additional $120.0 million in term loans for acquisitions, which was exercised on August 1, 2015 to finance the Kemmerer Drop. The WMLP Term Loan Facility matures in December 2018. Borrowings under the WMLP Term Loan Facility are secured by substantially all of WMLP’s physical assets. Proceeds from the credit facility were used to retire WMLP’s previously existing first and second lien credit facilities and to pay fees and expenses related to its existing credit facility, with the remaining proceeds being available as working capital. As of December 31, 2015 , the $299.2 million outstanding under the WMLP Term Loan Facility bears interest at a variable rate per annum equal to, at the WMLP’s option, the LIBOR floor of 0.75% plus 8.5% or the Reference Rate (as defined in the WMLP Financing Agreement). As of December 31, 2015 , the WMLP Term Loan Facility had a cash interest rate of 9.25% , consisting of the LIBOR floor ( 0.75% ) plus 8.5% . The WMLP Term Loan Facility also provides for Paid-In-Kind Interest (“PIK Interest”) at a variable rate per annum between 1.00% and 3.00% based on WMLP’s total net leverage ratio. 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 WMLP Term Loan Facility . PIK Interest under the WMLP Term Loan Facility was $6.9 million for the year ended December 31, 2015 . In connection with the Kemmerer Drop, the WMLP Term Loan Facility was amended on July 31, 2015 to (i) allow WMLP to make distributions in an aggregate amount not to exceed $15.0 million (previously $7.5 million ) without pro forma compliance with the consolidated total net leverage ratio or fixed charge coverage ratio, and (ii) at any time that WMLP has a revolving loan facility available, require it to have liquidity of at least $7.5 million (previously $5.0 million ), after giving effect to such distributions and applying availability under such revolving loan facility towards satisfying the liquidity requirement. The WMLP Term Loan Facility contains customary financial and other covenants. As of December 31, 2015 , WMLP was in compliance with all covenants under the terms of the WMLP Term Loan Facility . The WCC Revolving Credit Facility During the first quarter of 2014, the Company amended its WCC Revolving Credit Facility , or Revolver, to increase the maximum available borrowing amount to $60.0 million . On December 16, 2014, the Company further amended the WCC Revolving Credit Facility , decreasing the maximum borrowing amount to $50.0 million in the aggregate, consisting of a $30.0 million sub-facility available in the U.S. and a $20.0 million sub-facility available in Canada. Pursuant to a June 2, 2015 amendment to the WCC Revolving Credit Facility , Westmoreland has a total aggregate borrowing capacity of $75.0 million between June 15th and August 15 of each year. The Revolver may support an equal amount of letters of credit, which would reduce the balance available under the Revolver. At December 31, 2015 , availability under the WCC Revolving Credit Facility was $28.2 million with an outstanding balance of $19.8 million supporting letters of credit and a $2.0 million drawn on the revolver. All extensions of credit under the revolver are collateralized by a first priority security interest in and lien upon the inventory and accounts receivable of substantially all of the Company’s subsidiaries (other than Absaloka Coal, LLC, Westmoreland Risk Management, Inc.,Westmoreland Resources GP, LLC, Westmoreland Resource Partners, LP and certain other immaterial subsidiaries). Pursuant to the Intercreditor Agreement, the holders of the 8.75% Notes and the WCC Term Loan Facility have a subordinate lien on these assets. The Revolver has a maturity date of December 31, 2018. The Company capitalized debt issuance costs of $0.7 million in 2014 related to the Revolver amendments. Borrowings under the Revolver initially bear interest either at a rate 0.75% in excess of the base rate (as detailed in the Second Amended and Restated Loan Agreement) or at a rate 2.75% per annum in excess of LIBOR, at the Borrowers’ election. An unused line fee of 0.50% per annum is payable monthly on the average unused amount of the revolver. The loan agreement contains various affirmative, negative and financial covenants. Financial covenants in the agreement include certain fixed charge coverage ratios. The fixed charge coverage ratios must meet or exceed certain specified minimums. The Company met these covenant requirements as of December 31, 2015 . Capital Leases The Company engages in leasing transactions for equipment utilized in its mining operations. At December 31, 2015 and 2014 , the capital leases outstanding had a weighted average interest rate of 4.51% and 4.66% , respectively, and mature at various dates beginning in 2016 through 2020. During the year ended December 31, 2015 , the Company entered into $15.2 million of new capital leases.

POSTRETIREMENT MEDICAL BENEFITS

POSTRETIREMENT MEDICAL BENEFITS	12 Months Ended
	Dec. 31, 2015
Postretirement Health Coverage [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
POSTRETIREMENT MEDICAL BENEFITS	9. POSTRETIREMENT MEDICAL BENEFITS The Company provides postretirement medical benefits to retired employees and their dependents, mandated by the Coal Industry Retiree Health Act of 1992 and pursuant to collective bargaining agreements. The Company also provides these benefits to qualified full-time employees pursuant to collective bargaining agreements. These benefits are provided through self-insured programs. The following table sets forth the actuarial present value of postretirement medical benefit obligations and amounts recognized in the Company’s financial statements: December 31, 2015 2014 (In thousands) Change in benefit obligations: Net benefit obligation at beginning of year $ 306,418 $ 284,329 Service cost 4,217 3,289 Interest cost 11,629 12,814 Plan participant contributions 185 149 Actuarial loss (gain) (7,322 ) 19,441 Gross benefits paid (17,013 ) (14,860 ) Federal subsidy on benefits paid 1,259 1,256 Net benefit obligation at end of year 299,373 306,418 Change in plan assets: Employer contributions 16,828 14,711 Plan participant contributions 185 149 Gross benefits paid (17,013 ) (14,860 ) Fair value of plan assets at end of year — — Unfunded status at end of year $ (299,373 ) $ (306,418 ) Amounts recognized in the balance sheet consist of: Current liabilities $ (13,855 ) $ (13,263 ) Noncurrent liabilities (285,518 ) (293,156 ) Accumulated other comprehensive loss 31,085 39,716 Net amount recognized $ (268,288 ) $ (266,703 ) Amounts recognized in accumulated other comprehensive loss consists of: Net actuarial loss $ 35,534 $ 44,800 Prior service credit (4,449 ) (5,084 ) $ 31,085 $ 39,716 The Company has elected to amortize its transition obligations over a 20 -year period. Prior service costs and credits and actuarial gains and losses are amortized over the average life expectancy or average future service of the plan’s participants. The following amounts will be amortized from accumulated other comprehensive loss into net periodic benefit cost in 2016 (in millions): Actuarial loss $ 1.4 Prior service credit (0.6 ) The components of net periodic postretirement medical benefit cost are as follows: Years Ended December 31, 2015 2014 2013 (In thousands) Components of net periodic benefit cost: Service cost $ 4,217 $ 3,289 $ 4,436 Interest cost 11,629 12,814 12,139 Amortization of: Prior service credit (636 ) (635 ) (636 ) Actuarial loss 1,944 653 4,641 Total net periodic benefit cost $ 17,154 $ 16,121 $ 20,580 The following table shows the net periodic postretirement medical benefit costs that relate to current and former mining operations: Years Ended December 31, 2015 2014 2013 (In thousands) Former mining operations $ 8,137 $ 9,614 $ 12,475 Current operations 9,017 6,507 8,105 Total net periodic benefit cost $ 17,154 $ 16,121 $ 20,580 The costs for the former mining operations are included in Heritage health benefit expenses and the costs for current operations are included as operating expenses. Assumptions The weighted-average assumptions used to determine the benefit obligations as of the end of each year were as follows: December 31, 2015 2014 Discount rate 4.10% - 4.65% 3.75% - 4.25% Measurement date December 31, 2015 December 31, 2014 The discount rate is adjusted annually based on an Aa corporate bond index adjusted for the difference in the duration of the bond index and the duration of the benefit obligations. This rate is calculated using a yield curve, which is developed using the average yield for bonds in the tenth to ninetieth percentiles, which excludes bonds with outlier yields. The weighted-average assumptions used to determine net periodic benefit cost were as follows: December 31, 2015 2014 2013 Discount rate 3.75% - 4.25% 4.50% - 5.05% 3.60% - 4.15% Measurement date December 31, 2014 December 31, 2013 December 31, 2012 The following presents information about the assumed health care trend rate: December 31, 2015 2014 Health care cost trend rate assumed for next year 7.00 % 6.50 % Rate to which the cost trend is assumed to decline (ultimate trend rate) 4.75 % 5.00 % Year that the trend rate reaches the ultimate trend rate 2025 2021 The effect of a one percent change on the health care cost trend rate used to calculate periodic postretirement medical benefit costs and the related benefit obligation are summarized in the table below: Postretirement Medical Benefits 1 % Increase 1 % Decrease (In thousands) Effect on service and interest cost components $ 3,235 $ (2,444 ) Effect on postretirement medical benefit obligation $ 41,360 $ (33,667 ) Cash Flows The following benefit payments and Medicare D subsidy (which the Company receives as a benefit partially offsetting its prescription drug costs for retirees and their dependents) are expected by the Company: Postretirement Medical Benefits Medicare D Subsidy Net Postretirement Medical Benefits (In thousands) 2016 $ 13,855 $ (1,388 ) $ 12,467 2017 14,250 (1,457 ) 12,793 2018 14,744 (1,516 ) 13,228 2019 15,205 (1,573 ) 13,632 2020 15,627 (1,623 ) 14,004 Years 2021 - 2025 82,997 (8,830 ) 74,167 Combined Benefit Fund Additionally, the Company makes payments to the UMWA Combined Benefit Fund, or CBF, which is a multiemployer health plan neither controlled by nor administered by the Company. The CBF is designed to pay health care benefits to UMWA workers (and dependents) who retired prior to 1976. The Company is required by the Coal Act to make monthly premium payments into the CBF. These payments are based on the number of the Company’s UMWA employees who retired prior to 1976, and the Company’s pro-rata assigned share of UMWA retirees whose companies are no longer in business. Contributions to the CBF have decreased over the past three years due to a declining population. The Company expenses payments to the CBF when they are due. The following payments were made to the CBF (in millions): 2015 $ 1.8 2014 2.0 2013 2.2 Workers’ Compensation Benefits The Company was self-insured for workers’ compensation benefits prior to January 1, 1996. Since 1996, the Company has purchased third-party insurance for workers’ compensation claims. The following table shows the changes in the Company’s workers’ compensation obligation: December 31, 2015 2014 (In thousands) Workers’ compensation, beginning of year (including current portion) $ 6,986 $ 7,461 Accretion 127 200 Claims paid (448 ) (405 ) Actuarial changes (1,007 ) (270 ) Workers’ compensation, end of year 5,658 6,986 Less current portion, included in Other current liabilities (590 ) (671 ) Workers’ compensation, less current portion $ 5,068 $ 6,315 The discount rates used in determining the workers’ compensation benefit accruals are adjusted annually based on ten -year Treasury bond rates. At December 31, 2015 and 2014 , the rates were 2.2% and 2.0% , respectively. Black Lung Benefits The Company is self-insured for federal and state black lung benefits for former heritage employees and has established an independent trust to pay these benefits. The following table sets forth the funded status of the Company’s black lung obligation: December 31, 2015 2014 (In thousands) Actuarial present value of benefit obligation: Expected claims from terminated employees $ 2,472 $ 953 Amounts owed to existing claimants 15,318 13,054 Total present value of benefit obligation 17,790 14,007 Plan assets at fair value 570 2,755 Excess of the black lung benefit obligation over trust assets $ 17,220 $ 11,252 The discount rates used in determining the actuarial present value of the black lung benefit obligation are based on corporate bond yields and are adjusted annually. At December 31, 2015 and 2014 , the rates used were 3.95% and 3.40% , respectively. Plan Assets The Company's trust assets include cash and cash equivalents and U.S treasury securities, and are all valued at level 1 in the fair value hierarchy (refer to Note 14 - Fair Value Measurements ). The fair value of all trust assets is determined based on quoted prices in active markets. The fair value of the Company’s Black Lung trust assets by asset category is as follows: Fair Value as of December 31, 2015 December 31, 2014 (In thousands) U.S. treasury securities $ 256 $ 2,615 Cash and cash equivalents 314 140 $ 570 $ 2,755

PENSION AND OTHER SAVING PLANS

PENSION AND OTHER SAVING PLANS	12 Months Ended
	Dec. 31, 2015
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
PENSION AND OTHER SAVING PLANS	10. PENSION AND OTHER SAVING PLANS Defined Benefit Pension Plans The Company provides defined benefit pension plans to qualified full-time employees pursuant to collective bargaining agreements. Benefits are generally based on years of service and the employee’s average annual compensation for the highest five continuous years of employment as specified in the plan agreement. The Company’s funding policy is to contribute annually the minimum amount prescribed, as specified by applicable regulations. The Company may make additional discretionary contributions. In 2009, the Company froze its pension plan for non-represented employees. Supplemental Executive Retirement Plan The Company maintains a Supplemental Executive Retirement Plan or SERP for former executives as a result of employment or severance agreements. The SERP is an unfunded non-qualified deferred compensation plan, which provides benefits to certain employees beyond the maximum limits imposed by the Employee Retirement Income Security Act and the Internal Revenue Code. The Company does not expect to add new participants to its SERP plan. The following table provides a reconciliation of the changes in the benefit obligations of the plans and the fair value of assets of the qualified plans and the amounts recognized in the Company’s financial statements for both the defined benefit pension and SERP plans: Defined Benefit Pension December 31, SERP December 31, 2015 2014 2015 2014 (In thousands) Change in benefit obligation: Net benefit obligation at beginning of year $ 206,966 $ 155,075 $ 4,129 $ 3,640 Liability acquired — 36,087 — — Service cost 1,760 2,425 — — Interest cost 7,282 7,963 153 168 Actuarial loss (gain) (11,514 ) 32,505 (108 ) 704 Benefits and expenses paid (17,974 ) (15,119 ) (372 ) (383 ) Settlements and curtailments (1,559 ) (10,862 ) — — Plan amendments — 207 — — Foreign currency exchange rate changes (3,532 ) (1,315 ) — — Net benefit obligation at end of year 181,429 206,966 3,802 4,129 Change in plan assets: Fair value of plan assets at the beginning of year 160,947 134,149 — — Assets acquired — 36,616 — — Actual return on plan assets (2,379 ) 14,392 — — Employer contributions 3,727 4,812 372 383 Benefits and expenses paid (17,974 ) (15,119 ) (372 ) (383 ) Settlements 124 (12,795 ) — — Foreign currency exchange rate changes (3,308 ) (1,108 ) — — Fair value of plan assets at end of year 141,137 160,947 — — Unfunded status at end of year $ (40,292 ) $ (46,019 ) $ (3,802 ) $ (4,129 ) Amounts recognized in the accompanying balance sheet consist of: Noncurrent asset, included in Other assets $ 1,082 $ — $ — $ — Current liability — — (368 ) (368 ) Noncurrent liability (41,374 ) (46,019 ) (3,434 ) (3,760 ) Accumulated other comprehensive loss 33,313 34,249 1,589 1,815 Net amount recognized at end of year $ (6,979 ) $ (11,770 ) $ (2,213 ) $ (2,313 ) Amounts recognized in accumulated other comprehensive loss consist of: Net actuarial loss $ 33,236 $ 34,164 $ 1,589 $ 1,815 Prior service cost 77 85 — — $ 33,313 $ 34,249 $ 1,589 $ 1,815 Prior service costs and actuarial gains and losses are amortized over the expected future period of service of the plan’s participants. The following amounts will be amortized from accumulated other comprehensive loss into net periodic benefit cost in 2016 (in millions): Pension SERP Net actuarial loss $ 5.6 $ 0.1 The components of net periodic benefit cost are as follows: Defined Benefit Pension Years Ended December 31, SERP Years Ended December 31, 2015 2014 2013 2015 2014 2013 (In thousands) Components of net periodic benefit cost: Service cost $ 1,760 $ 2,425 $ 2,346 $ — $ — $ — Interest cost 7,282 7,963 6,209 153 168 152 Expected return on plan assets (10,033 ) (10,796 ) (8,770 ) — — Settlements and curtailments (1,683 ) 4,585 — — — — Amortization of: Prior service cost 8 — — — — — Actuarial loss 2,840 1,217 3,377 118 97 112 Total net periodic pension cost $ 174 $ 5,394 $ 3,162 $ 271 $ 265 $ 264 These costs are included in the accompanying statements of operations in Cost of sales and Selling and administrative expenses. In certain of the Company's pension plans, lump sum distributions during 2014 exceeded the sum of those plans' service and interest costs. As a result, the Company recorded a $3.7 million loss on settlement accounting in 2014. In addition, the Company recorded a $0.9 million loss on curtailment accounting due to the expectation that the future service of present employees at the Beulah Mine will be significantly reduced in the future. These costs are included in the accompanying statements of operations in Selling and administrative expenses. Assumptions The weighted-average assumptions used to determine the benefit obligations as of the end of each year were as follows: Defined Benefit Pension December 31, SERP December 31, 2015 2014 2015 2014 Discount rate 3.90% - 4.25% 3.60% - 3.90% 4.25% 3.90% Measurement date December 31, 2015 December 31, 2014 December 31, 2015 December 31, 2014 The discount rate is adjusted annually based on an Aa corporate bond index adjusted for the difference in the duration of the bond index and the duration of the benefit obligations. This rate is calculated using a yield curve, which is developed using the average yield for bonds in the tenth to ninetieth percentiles, which excludes bonds with outlier yields. The following table provides the assumptions used to determine net periodic benefit cost: Defined Benefit Pension Years Ended December 31, SERP Years Ended December 31, 2015 2014 2013 2015 2014 2013 Discount rate 3.60% - 3.90% 4.25% - 4.70% 3.35% - 3.75% 3.90% 4.65% 3.75% Expected return on plan assets 3.66% - 7.10% 7.40% 7.40% N/A N/A N/A Rate of compensation increase N/A N/A N/A N/A N/A N/A Measurement date December 31, 2014 December 31, 2013 December 31, 2012 December 31, 2014 December 31, 2013 December 31, 2012 The Company establishes the expected long-term rate of return at the beginning of each fiscal year based upon historical returns and projected returns on the underlying mix of invested assets. The Company utilizes modern portfolio theory modeling techniques in the development of its return assumptions. This technique projects rates of return that can be generated through various asset allocations that lie within the risk tolerance set forth by the Company. The risk assessment provides a link between a pension plan's risk capacity, management's willingness to accept investment risk and the asset allocation process, which ultimately leads to the return generated by the invested assets. Plan Assets The Company’s investment goals are to maximize returns subject to specific risk management policies. The Company sets the expected return on plan assets based on historical trends and forecasts provided by its third-party fund managers. Its risk management policies permit investments in mutual funds, and prohibit direct investments in debt and equity securities and derivative financial instruments. The Company addresses diversification by the use of mutual fund investments whose underlying investments are in fixed income and equity securities, both domestic and international. These mutual funds are readily marketable and can be sold to fund benefit payment obligations as they become payable. The weighted-average target asset allocation of the Company’s pension trusts were as follows at December 31, 2015 : Target Allocation Asset category Cash and equivalents 0% - 10% Equity securities funds 20% - 60% Debt securities funds 40% - 80% Other 0% - 10% The fair value of the Company’s pension plan assets by asset category is as follows: December 31, 2015 Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Fair Value Level 1 Level 2 Level 3 (In thousands) Pooled separate accounts: Large-cap blend (a) $ 43,417 $ — $ 43,417 $ — International blend (b) 7,779 — 7,779 — Fixed income domestic (c) 22,115 — 22,115 — Fixed income long term (d) 43,091 — 43,091 — Stable value (e) 4,937 — 4,937 — Registered investment companies – growth fund 15,447 15,447 — — Limited partnerships and limited liability companies 136 — — 136 Westmoreland Coal common stock 273 273 — — Cash and cash equivalents 3,942 3,942 — — $ 141,137 $ 19,662 $ 121,339 $ 136 December 31, 2014 Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Fair Value Level 1 Level 2 Level 3 (In thousands) Pooled separate accounts: Large-cap blend (a) $ 47,092 $ — $ 47,092 $ — International blend (b) 7,290 — 7,290 — Fixed income domestic (c) 23,057 — 23,057 — Fixed income long term (d) 47,299 — 47,299 — Stable value (e) 5,346 — 5,346 — Registered investment companies – growth fund 16,490 16,490 — — Limited partnerships and limited liability companies 224 — — 224 Westmoreland Coal common stock 1,539 1,539 — — Cash and cash equivalents 12,610 12,610 — — $ 160,947 $ 30,639 $ 130,084 $ 224 (a) Large-cap blend funds seek to provide long-term growth of capital. They seek to provide investment results that approximate the performance of the Standard & Poor’s Composite 1500 Index. (b) International blends seek to have a diversified portfolio of investments, invading fixed-income and equity-focused investments in international markets. (c) Fixed income domestic funds seek to invest in high-quality corporate bonds with over 15 years to maturity. (d) Fixed income long term bond funds seek to achieve performance results similar to the Barclays Capital U.S. Aggregate Bond Index. This fund invests primarily in corporate and government bonds. (e) The stable value fund seeks to invest in publicly traded and privately placed debt securities and mortgage loans, and to a lesser extent, real estate and other equity investments in order to provide a guaranteed rate of return. The Company’s Level 1 assets include securities held by registered investment companies and its common stock, which are both typically valued using quoted market prices of an active market. Cash and cash equivalents and short-term investments are predominantly held in money market accounts. The Company’s Level 2 assets include pooled separate accounts, which are valued based on the quoted market prices of the securities underlying the investments. The Company’s Level 3 assets include interest in limited partnerships and limited liability companies that invest in privately held companies or privately held real estate assets. These assets are valued by the respective partnership or company manager using market and income approaches. The market approach consists of using comparable market transactions or values. The income approach consists of the net present value of estimated future cash flows, adjusted as appropriate for liquidity, credit, market and other risk factors. The inputs considered in the valuations include original transaction prices, recent transactions in the same or similar instruments, changes in financial ratios or cash flows, discounted cash flow valuations, and general economic and market conditions. Contributions The Company contributed $3.7 million in cash to its retirement plans during 2015 . In 2016 , the Company expects to make approximately $0.5 million of pension plan contributions. Cash Flows The following benefit payments are expected to be paid from its pension plan assets: Pension Benefits (In thousands) 2016 $ 10,846 2017 9,048 2018 9,280 2019 9,758 2020 10,111 Years 2021 - 2025 54,006 The benefits expected to be paid are based on the same assumptions used to measure the Company’s pension benefit obligation at December 31, 2015 and include estimated future employee service. Multi-Employer Pension The Company contributes to the Central Pension Fund, or the Plan, a multiemployer defined benefit pension plan for its WECO, WRI and WSC entities pursuant to collective bargaining agreements. The Plan’s Employer Identification Number is 36-6052390. These employers contribute to the Plan based on a negotiated rate per hour worked per participating employee. For the Plan’s year-end dates of January 31, 2015 and 2014 , no single employer contributed more than 5% of total contributions to the Plan. As of the Plan’s year-end date January 31, 2015 , it had a healthy or greater than 80% funding status. The following table shows required information for each employer contributing to the Central Pension Fund: WECO WRI WSC Employer plan number 9313 9243 4990 Minimum contributions per hour worked $5.85 - $5.90 $4.03 - $4.39 $ 3.70 Expiration date of collective bargaining agreements 2/28/2019 5/31/2021 3/31/2022 Employer contributions (in millions): 2015 $ 3.6 $ 1.1 $ 0.1 2014 3.3 1.2 0.1 2013 3.4 0.9 0.1 Other Plans The Company sponsors 401(k) saving plans for U.S. employees and provides contributions to employee savings plans at its Canadian operation to assist employees in providing for their future retirement needs. The Company’s expense was $10.8 million , $8.5 million and $3.6 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. During 2015 , the Company’s expense of $10.8 million consisted of $7.1 million in cash contributions and $3.7 million in contributions of Company stock to the plans. During 2014 , the Company’s expense of $8.5 million consisted of $ 6.7 million in cash contributions and $1.8 million in contributions of Company stock to the plans. During 2013 , the Company’s expense of $3.6 million consisted of $1.2 million in cash contributions and $2.4 million in contributions of Company stock to the plans.

HERITAGE HEALTH BENEFIT EXPENSE

HERITAGE HEALTH BENEFIT EXPENSES	12 Months Ended
	Dec. 31, 2015
Heritage Health Benefit Expenses [Abstract]
HERITAGE HEALTH BENEFIT EXPENSES	11. HERITAGE HEALTH BENEFIT EXPENSES The caption Heritage health benefit expenses used in the consolidated statements of operations refers to costs of benefits the Company provides to its former mining operation employees. The components of these expenses are as follows: Years Ended December 31, 2015 2014 2013 (In thousands) Health care benefits $ 8,179 $ 9,473 $ 12,579 Combined benefit fund payments 1,794 1,966 2,240 Workers’ compensation benefits (credit) (583 ) 230 (1,212 ) Black lung benefits (credit) 5,183 1,719 (189 ) Total $ 14,573 $ 13,388 $ 13,418

ASSET RETIREMENT OBLIGATIONS, C

ASSET RETIREMENT OBLIGATIONS, CONTRACTUAL THIRD-PARTY RECLAMATION RECEIVABLES, AND RECLAMATION DEPOSITS	12 Months Ended
	Dec. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]
ASSET RETIREMENT OBLIGATIONS, CONTRACTUAL THIRD-PARTY RECLAMATION RECEIVABLES, AND RECLAMATION DEPOSITS	12. ASSET RETIREMENT OBLIGATIONS, CONTRACTUAL THIRD-PARTY RECLAMATION RECEIVABLE, AND RECLAMATION DEPOSITS The asset retirement obligations (“ARO”), contractual third-party reclamation receivables, and reclamation deposits at December 31, 2015 are summarized below: Asset Retirement Obligations Contractual Third-Party Reclamation Receivables Reclamation Deposits (In thousands) Coal - U.S. $ 251,116 $ 89,408 $ 77,364 Coal - Canada 110,978 5,527 — Coal - WMLP 56,634 — — Power 1,035 — — Total $ 419,763 $ 94,935 $ 77,364 Asset Retirement Obligations Changes in the Company’s asset retirement obligations were as follows: Years Ended December 31, 2015 2014 (In thousands) Asset retirement obligations, beginning of year (including current portion) $ 452,745 $ 279,864 Accretion 38,891 31,033 Liabilities settled (30,363 ) (23,935 ) Changes due to amount and timing of reclamation (24,533 ) 10,042 Asset retirement obligations acquired 4,146 162,394 Changes due to foreign currency translation (21,123 ) (6,653 ) Asset retirement obligations, end of year 419,763 452,745 Less current portion (43,950 ) (43,289 ) Asset retirement obligations, less current portion $ 375,813 $ 409,456 The Company or its subsidiaries are responsible for the total amount of final reclamation costs for its mines and ROVA. The financial responsibility for a portion of final reclamation of the mines when they are closed has been transferred by contract to certain customers, while other customers have provided guarantees or funded escrow accounts to cover final reclamation costs. Costs of reclamation of mining pits prior to mine closure are recovered in the price of coal shipped. As of December 31, 2015 , the Company had $384.1 million in surety bonds outstanding and $103.2 million in letters of credit to secure reclamation obligations. Contractual Third-Party Reclamation Receivables The Company has recognized as an asset of $94.9 million as contractual third-party reclamation receivables, representing the present value of customer obligations to reimburse the Company for reclamation expenditures. Reclamation Deposits The Company’s reclamation deposits will be used to fund final reclamation activities. The carrying value (which equals estimated fair value) of reclamation deposits at December 31, 2015 are as follows: (In thousands) Cash and cash equivalents $ 45,819 Available-for-sale securities 31,545 $ 77,364 In both 2015 and 2014 , the Company recorded a gain of less than $0.1 million on the sale of available-for-sale securities held as reclamation deposits. The cost basis of an investment sold is specifically identified. Available-for-Sale Reclamation Deposits The cost basis, gross unrealized holding gains and fair value of available-for-sale securities are as follows: December 31, 2015 2014 (In thousands) Cost basis $ 31,977 $ 32,930 Gross unrealized holding gains 521 886 Gross unrealized holding losses (953 ) (428 ) Fair value $ 31,545 $ 33,388 Maturities of available-for-sale securities are as follows at December 31, 2015 : Cost Fair Value (In thousands) Within one year $ 592 $ 529 Due in five years or less 16,156 16,049 Due after five years to ten years 6,207 5,925 Due in more than ten years 9,022 9,042 $ 31,977 $ 31,545

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS	13. DERIVATIVE INSTRUMENTS Derivative Liabilities The Company evaluates all of its financial instruments to determine if such instruments are derivatives, derivatives that qualify for the normal purchase normal sale exception, or contain features that qualify as embedded derivatives. All derivative financial instruments, except for derivatives that qualify for the normal purchase normal sale exception, are recognized on the balance sheet at fair value. Changes in fair value are recognized in earnings if they are not eligible for hedge accounting or in other comprehensive income if they qualify for cash flow hedge accounting. In the first quarter of 2014, the Company entered into two foreign currency exchange forward contracts to purchase Canadian Dollars to manage a portion of its exposure to fluctuating rates of exchange on anticipated Canadian Dollar-denominated Canadian Acquisition cash flows. These two foreign currency contracts had a total notional amount of $348.3 million and were settled in April 2014. During 2014, the Company entered into contracts to purchase power at its ROVA facility to manage exposure to power price fluctuations. These contracts cover the period from April 2014 to March 2019. Over the remaining contract lives, contracted power prices range from $41.05 to $55.20 per megawatt hour with a weighted average price of $43.93 . The fair value of these power price derivatives are based on comparing contracted prices to projected future prices. The fair value of outstanding derivative instruments not designated as hedging instruments on the accompanying Consolidated Balance Sheets was as follows (in thousands): Derivative Instruments Balance Sheet Location December 31, 2015 December 31, 2014 Contracts to purchase power Other current liabilities $ 13,679 $ 8,265 Contracts to purchase power Other liabilities 23,656 21,103 $ 37,335 $ 29,368 The effect of derivative instruments not designated as hedging instruments on the accompanying Consolidated Statements of Operations was as follows (in thousands): Year Ended December 31, Derivative Instruments Statement of Operations Location 2015 2014 Canadian dollar foreign exchange contracts Gain (loss) on foreign exchange $ — $ (6,209 ) Contracts to purchase power Derivative loss (5,587 ) (31,100 )

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	14. FAIR VALUE MEASUREMENTS 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. The Company is required to 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, 2015 (Level 3). The estimated fair value of the Company’s debt with fixed and variable interest rates are as follows: Fixed Interest Rate Variable Interest Rate Carrying Value Fair Value Carrying Value Fair Value (In thousands) (In thousands) December 31, 2015 $ 345,984 $ 213,500 $ 619,341 $ 388,380 December 31, 2014 $ 345,533 $ 348,283 $ 516,300 $ 519,750 The table below sets forth, by level, the Company’s financial assets and liabilities that are accounted for at fair value on a recurring basis: Balance at December 31, 2015 Quoted Prices in Active Markets for Identical Assets or Liabilities Significant Other Observable Inputs Fair Value Level 1 Level 2 (In thousands) Assets: Available-for-sale investments included in Restricted investments and bond collateral $ 35,813 $ 35,813 $ — Available-for-sale investments included in Reclamation deposits 31,545 31,545 — $ 67,358 $ 67,358 $ — Liabilities: Contracts to purchase power included in Other current liabilities and Other liabilities $ (37,335 ) $ — $ (37,335 ) Warrants issued by WMLP included in Other liabilities (646 ) (646 ) $ (37,981 ) $ (646 ) $ (37,335 ) Balance at December 31, 2014 Quoted Prices in Active Markets for Identical Assets or Liabilities Significant Other Observable Inputs Fair Value Level 1 Level 2 (In thousands) Assets: Available-for-sale investments included in Restricted investments and bond collateral $ 34,057 $ 34,057 $ — Available-for-sale investments included in Reclamation deposits 33,388 33,388 — $ 67,445 $ 67,445 $ — Liabilities: Contracts to purchase power included in Other current liabilities and Other liabilities $ (29,368 ) $ — $ (29,368 ) Warrants issued by WMLP included in Other liabilities (1,981 ) (1,981 ) $ (31,349 ) $ (1,981 ) $ (29,368 )

RESTRICTED STOCK UNITS, STOCK O

RESTRICTED STOCK UNITS, STOCK OPTIONS, AND STOCK APPRECIATION RIGHTS (SARs)	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
RESTRICTED STOCK UNITS, STOCK OPTIONS, AND STOCK APPRECIATION RIGHTS (SARs)	15. RESTRICTED STOCK UNITS, STOCK OPTIONS, AND STOCK APPRECIATION RIGHTS (SARs) As of December 31, 2015 , the Company had restricted stock units, stock options, and stock-settled stock appreciation rights, or SARs, outstanding from three stock incentive plans. Two of these plans were terminated in October 2009. The Company grants employees and non-employee directors restricted stock units from the Amended and Restated 2007 and 2014 Equity Incentive Stock Plans. The Company grants employees and non-employee directors restricted stock units. Non-employee directors receive equity awards with a value of $90,000 after each annual meeting. The maximum number of remaining shares that can be issued under the 2007 Incentive Stock Plan is 296,431 . The maximum number of remaining shares that can be issued under the 2014 Incentive Stock Plan is 526,460 . Compensation cost arising from share-based arrangements is shown in the following table: Years Ended December 31, 2015 2014 2013 (In thousands) Recognition of fair value of restricted stock units, stock options and SARs over vesting period; and issuance of stock $ 4,019 $ 4,318 $ 2,967 Contributions of stock to the Company’s 401(k) plan 3,729 1,764 2,355 Total share-based compensation expense $ 7,748 $ 6,082 $ 5,322 Restricted Stock Units The Company may issue restricted stock units, which requires no payment from the employee. Restricted stock units typically vest ratably over three years . Upon vesting, the Company can elect to settle the restricted stock units in either cash or the Company’s common stock. Compensation expense is based on the fair value on the grant date and is recorded ratably over the vesting period. In April 2015, the Company granted 233,974 restricted stock units, of which 117,003 units will vest ratably over a three -year period. The remaining 116,971 units are performance based, which will vest and pay out at the end of a three -year period if performance goals are met. The Company’s management believes it is probable that the target performance condition will be met. A summary of restricted stock award activity for the year ended December 31, 2015 is as follows: Units Weighted Average Grant-Date Fair Value Unamortized Compensation Expense (In thousands) Non-vested at December 31, 2014 409,362 $ 15.17 Granted 262,555 $ 28.26 Vested (256,937 ) $ 11.27 Forfeited (60,669 ) $ 11.13 Non-vested at December 31, 2015 354,311 $ 28.44 $ 6,572 (1) ____________________ (1) Expected to be recognized over the next three years . Additional information related to restricted stock units: Years Ended December 31: Weighted Average Grant-Date Fair Value Total Grant- Date Fair Value of Restricted Stock Units that Vested (In thousands) 2015 $ 28.26 $ 2,884 2014 $ 30.67 $ 3,536 2013 $ 11.70 $ 1,689 Stock Options Stock options generally vest over three years, expire ten years from the date of grant, and have an option price equal to the market value of the stock on the date of grant. Information with respect to stock option activity for the year ended December 31, 2015 , is as follows: Stock Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (In years) Aggregate Intrinsic Value (In thousands) Unamortized Compensation Expense (In thousands) Outstanding at December 31, 2014 110,806 $ 22.15 Exercised — Expired (1,500 ) $ 21.40 Outstanding and exercisable at December 31, 2015 109,306 $ 22.16 2.2 $ — $ — Additional information related to stock options: Years Ended December 31: Intrinsic Value of Stock Options Exercised 2015 $ — 2014 $ 11.81 2013 $ — There were no stock options granted during 2015 , 2014 or 2013 . SARs SARs generally vest over three years, expire ten years from the date of grant, and have a base price equal to the market value of the stock on the date of grant. Upon vesting, the holders may exercise the SARs and receive a number of shares of common stock having a value equal to the appreciation in the value of the common stock between the grant date and the exercise date. Information with respect to SARs granted and outstanding for the year ended December 31, 2015 is as follows: SARs Weighted Average Exercise Price Weighted Average Remaining Contractual Life (In years) Aggregate Intrinsic Value (In thousands) Unamortized Compensation Expense (In thousands) Outstanding at December 31, 2014 16,943 $ 25.44 Exercised — Expired — Outstanding and exercisable at December 31, 2015 16,943 $ 25.44 0.4 $ — $ — Additional information related to SARs: Years Ended December 31: Intrinsic Value of SARs Exercised 2015 $ — 2014 $ 11.50 2013 $ — There were no SARs granted or vested during 2015 , 2014 , or 2013 .

STOCKHOLDERS' EQUITY AND ACCUMU

STOCKHOLDERS' EQUITY AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
STOCKHOLDERS' EQUITY AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	16. STOCKHOLDERS’ EQUITY AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Noncontrolling Interest On acquisition of WMLP we recorded a noncontrolling interest totaling $15.3 million , which represents the equity attributable to the noncontrolling unitholders, who owned approximately 21% of the outstanding Common Units of WMLP at December 31, 2014. The Kemmerer Drop resulted in our acquisition of an additional 15% interest in WMLP (on a fully diluted basis) with a corresponding decrease in noncontrolling interest ownership. Activity in the noncontrolling interest is summarized as follows (in millions): Beginning Balance as of December 31, 2014 $ 15,261 Change in Parent's ownership (8,279 ) Net loss allocated to noncontrolling interest (5,453 ) Distributions to noncontrolling interest (797 ) Other — Ending Balance as of December 31, 2015 $ 732 Preferred and Common Stock The Company has one class of capital stock outstanding at December 31, 2015 , common stock, par value $0.01 per share. During the first quarter of 2015, all of the Company’s Series A Convertible Exchangeable Preferred Stock were converted or redeemed, consisting of 88,494 shares of preferred stock being converted into 604,557 shares of common stock and 3,175 shares of preferred stock were redeemed under a mandatory redemption for $0.3 million . The Company paid less than $0.1 million of preferred stock dividends for the year ended December 31, 2015 . Accumulated Other Comprehensive Income (Loss) The following is a summary of accumulated other comprehensive income (loss): Pension and Postretirement Medical Benefits Available for Sale Securities Foreign Currency Translation Adjustment Tax Effect of Other Comprehensive Income Gains Accumulated Other Comprehensive Loss (In thousands) Balance at January 1, 2013 $ (122,246 ) $ 57 $ — $ (26,156 ) $ (148,345 ) 2013 activity 89,699 (57 ) — (4,892 ) 84,750 Balance at December 31, 2013 (32,547 ) — — (31,048 ) (63,595 ) 2014 activity (43,234 ) 413 (17,880 ) — (60,701 ) Balance at December 31, 2014 (75,781 ) 413 (17,880 ) (31,048 ) (124,296 ) 2015 activity 10,137 (1,738 ) (52,021 ) (3,382 ) (47,004 ) Balance at December 31, 2015 $ (65,644 ) $ (1,325 ) $ (69,901 ) $ (34,430 ) $ (171,300 ) Changes in Accumulated Other Comprehensive Loss The following table reflects the changes in accumulated other comprehensive loss by component: Pension Postretirement Available for sale securities Foreign currency translation adjustment Tax effect of other comprehensive income gains Accumulated other comprehensive loss (In thousands) Balance at December 31, 2014 $ (36,065 ) $ (39,716 ) $ 413 $ (17,880 ) $ (31,048 ) $ (124,296 ) Other comprehensive income (loss) before reclassifications (853 ) 7,322 (1,887 ) (52,021 ) (3,382 ) (50,821 ) Amounts reclassified from accumulated other comprehensive loss 2,360 1,308 149 — — 3,817 Balance at December 31, 2015 $ (34,558 ) $ (31,086 ) $ (1,325 ) $ (69,901 ) $ (34,430 ) $ (171,300 ) The following table reflects the reclassifications out of accumulated other comprehensive loss for the year ended December 31, 2015 (in thousands): Details about accumulated other comprehensive income (loss) components Amount reclassified from accumulated other comprehensive income (loss) (1) Affected line item in the statement where net income (loss) is presented Available-for sale securities Realized gains and losses on available-for sale securities $ 149 Other income (loss) $ 149 Total Amortization of defined benefit pension items: Prior service costs $ 8 (2) Actuarial losses 2,352 (2) $ 2,360 Total Amortization of postretirement medical items: Prior service costs $ (636 ) (3) Actuarial losses 1,944 (3) $ 1,308 Total ____________________ (1) Amounts in parentheses indicate debits to income/loss. (2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost. (See Note 10 - Pension And Other Saving Plans for additional details) (3) These accumulated other comprehensive income components are included in the computation of net periodic postretirement medical cost. (See Note 9 - Postretirement Medical Benefits for additional details) Restricted Net Assets WCC has obligations to pay pension and postretirement medical benefits, to fund corporate expenditures, and to pay interest on the 8.75% Notes and the WCC Term Loan Facility . However, WCC conducts no operations, has no source of revenue and is fully dependent on distributions from its subsidiaries to pay its costs. Due to the Master Limited Partnership structure and the WMLP Term Loan Facility , at December 31, 2015 , WMLP is limited in its ability to distribute funds to WCC. The amount of cash WMLP can distribute on its units principally depends upon the amount of cash it generates from its operations, which will fluctuate from quarter to quarter. The WMLP Term Loan Facility contains customary financial and other covenants and it permits distributions to its unitholders under specified circumstances. Borrowings under the WMLP Term Loan Facility are secured by substantially all of its physical assets. At December 31, 2015 , WMLP had approximately $13.2 million of net assets that were not available to be transferred to WCC in the form of dividends, loans, or advances due to restrictions on the Master Limited Partnership as mentioned above. Equity Offering On July 16, 2014, the Company completed a public offering of 1,684,507 shares of common stock at $35.50 per share for gross proceeds of $59.8 million . Brokerage fees were $1.775 per share or $3.0 million and legal and other fees associated with the offering were $0.3 million .

INCOME TAX

INCOME TAX	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
INCOME TAX	17. INCOME TAX The Company is subject to U.S. and Canadian income tax as well as tax in multiple state jurisdictions. The tax years 2000 through 2015 remain open to examination for U.S. federal income tax matters. The Company’s income (loss) before income taxes is as follows: Years Ended December 31, 2015 2014 2013 (In thousands) United States $ (254,252 ) $ (157,043 ) $ (12,909 ) Foreign 25,718 (15,905 ) — Income (loss) before income taxes $ (228,534 ) $ (172,948 ) $ (12,909 ) Income tax expense (benefit) reflected in the consolidated statement of operations consisted of: Years Ended December 31, 2015 2014 2013 (In thousands) Current: Federal $ — $ — $ (2 ) State 12 120 112 Foreign 1,441 545 — 1,453 665 110 Deferred: Federal (3,295 ) — (4,189 ) State (330 ) — (703 ) Foreign (17,595 ) (433 ) — (21,220 ) (433 ) (4,892 ) Income tax expense (benefit) $ (19,767 ) $ 232 $ (4,782 ) The effective tax rate differs from the U.S. federal statutory rate as follows: Years Ended December 31, 2015 2014 2013 (In thousands) Computed income tax expense (benefit) at statutory rate $ (82,022 ) $ (58,066 ) $ (4,390 ) Tax depletion in excess of basis (5,317 ) (9,273 ) (6,187 ) Non-deductible acquisition costs — 2,979 — Intercompany interest (6,488 ) (4,174 ) 1,167 State and foreign income taxes, net (6,184 ) (9,706 ) 3,696 Change in valuation allowance for net deferred tax assets 132,338 77,771 15 Release of valuation allowance arising from amalgamation (32,635 ) — — Indian coal tax credits (“ICTC”) (13,756 ) (15,205 ) 92 Change in Canadian rate (3,081 ) — — Kemmerer deferred tax asset removal (13,238 ) — — Uncertain tax positions 3,994 — — Other, net 6,622 15,906 825 Income tax expense (benefit) $ (19,767 ) $ 232 $ (4,782 ) The $132.3 million increase in valuation allowance for the year ended December 31, 2015 is due to the tax effect of the change in current year temporary items, credits, net operating losses, and postretirement medical benefit and pension obligations. During 2015 the Company completed an amalgamation of two of our Canadian subsidiaries as part of a tax planning strategy. The amalgamation resulted in a decrease in the Company’s Canadian net deferred tax asset, necessitating the $32.6 million release of a portion of the Company’s valuation allowance. The $13.2 million Kemmerer deferred tax asset removal for the year ended December 31, 2015 is due to the Company dropping the Kemmerer mine and assets into the Company’s master limited partnership, Westmoreland Resource Partners, LP on August 1, 2015. The tax effects of temporary differences that give rise to the deferred tax assets and deferred tax liabilities are presented below: December 31, 2015 2014 (In thousands) Deferred tax assets: Net operating losses $ 198,216 $ 166,489 Credit carryforwards 62,219 47,872 Investment in WMLP 3,112 1,185 Accrued compensation and benefits 5,847 2,592 Asset retirement obligations 92,889 101,514 Postretirement medical benefit and pension obligations 123,595 124,854 Deferred revenue 13,591 15,841 Black lung accrual 7,405 4,244 Unrealized gain/(loss) on derivatives 14,377 11,078 Canadian resource pool 4,088 6,435 Lease obligations 13,341 23,401 Depreciable capital assets — 6,779 Other 5,896 13,514 Total deferred tax assets 544,576 525,798 Valuation allowance (497,796 ) (406,143 ) Net deferred tax assets 46,780 119,655 Deferred tax liabilities: Property, plant and equipment, differences due to depreciation and amortization $ (26,061 ) $ (113,430 ) Investment in joint venture (6,284 ) (7,324 ) Finance lease receivable (9,446 ) (15,232 ) Deferred reclamation revenue (1,492 ) (1,688 ) Other (3,497 ) (3,750 ) Total deferred tax liabilities (46,780 ) (141,424 ) Net deferred tax asset (liability) $ — $ (21,769 ) As of December 31, 2015 , the Company had significant deferred tax assets. The deferred tax assets include U.S. federal, state regular and foreign NOLs, AMT credit carryforwards, ICTC carryforwards, and net deductible reversing temporary differences related to on-going differences between book and taxable income. The Company determined that since its net deductible temporary differences will not reverse for the foreseeable future, and it is unable to forecast regular taxable income when they do reverse, a full valuation allowance is required for these deferred tax assets. The net valuation allowance increased by $91.7 million and $141.7 million during the years ended December 31, 2015 and December 31, 2014 respectively. As of December 31, 2015 , the Company has available U.S. federal net operating loss carryforwards to reduce future regular taxable income of $417.3 million , expiring between 2018 and 2035. The Company has ICTC carryforwards of $54.5 million available to reduce future income taxes, which expire between 2026 and 2035. Currently the Company has an excess tax over book basis in its investment in Canadian subsidiaries and the Company does not expect this deferred tax asset to reverse in the foreseeable future. Accordingly, there has been no recognition of any deferred tax asset on the outside basis of investments in subsidiaries, in accordance with ASC 740. Foreign Income Taxes As of December 31, 2015 , the Company has available foreign net operating loss carryforwards to reduce future regular taxable income of approximately $92.9 million expiring in years 2031 through 2035. Uncertain tax positions The Company recorded $4.0 million and zero in uncertain tax positions for the year ended December 31, 2015 and December 31, 2014 , respectively. The Company recognizes interest and penalties related to income tax matters in income tax expense, for which none was recorded for the years ended December 31, 2015 , 2014 or 2013 . No uncertain tax positions are expected to change in the next 12 months.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	18. COMMITMENTS AND CONTINGENCIES Leases and other Commitments The following shows the gross value and accumulated amortization of property, plant and equipment and mine development assets under capital leases related primarily to the leasing of mining equipment as of December 31: 2015 2014 (In thousands) Gross value $ 65,293 $ 74,203 Accumulated amortization 25,878 21,598 Future minimum capital and operating lease payments as of December 31, 2015 , are as follows: Capital Leases Operating Leases (In thousands) 2016 $ 35,467 $ 12,390 2017 27,695 7,409 2018 6,497 5,488 2019 4,336 4,421 2020 1,297 660 Thereafter — 2,360 Total minimum lease payments 75,292 $ 32,728 Less imputed interest (4,124 ) Present value of minimum capital lease payments $ 71,168 Rental expense under operating leases during the years ended December 31, 2015 , 2014 and 2013 totaled $25.2 million , $16.6 million and $11.8 million , respectively. The Company leases certain of its coal reserves from third parties and pays royalties based on either a per ton rate or as a percentage of revenues received. Royalties charged to expense under all such lease agreements amounted to $96.7 million , $61.8 million and $43.6 million in the years ended December 31, 2015 , 2014 and 2013 , respectively. At December 31, 2015 , the Company had fuel supply contracts outstanding with a minimum purchase requirement of 3.9 million gallons of diesel fuel per year. These contracts qualify for the normal purchase normal sale exception under hedge accounting. Contingencies The Company is a party to various claims and lawsuits with respect to various matters. The Company provides for costs related to contingencies when a loss is probable and the amount is reasonably estimable. After conferring with counsel, it is the opinion of management that the ultimate resolution of pending claims will not have a material adverse effect on the consolidated financial condition, results of operations, or liquidity of the Company. As part of the Canadian Acquisition in 2014, the Company became responsible for remediation work for a breach on a containment pond at a currently inactive mine that occurred on October 31, 2013. The prior owner, Sherritt International Corporation, has indemnified Westmoreland against past and future liability stemming from the incident. As of December 31, 2015 , the Company has recorded $8.1 million in Other current liabilities for the estimated costs of remediation work and a corresponding amount in current receivables Other to reflect the indemnification by the prior owner.

BUSINESS SEGMENT INFORMATION

BUSINESS SEGMENT INFORMATION	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
BUSINESS SEGMENT INFORMATION	19. BUSINESS SEGMENT INFORMATION Segment information is based on a management approach, which requires segmentation based upon the Company’s internal organization, reporting of revenue, and operating income. The Company’s operations are classified into six reporting segments: Coal - U.S., Coal - Canada, Coal - WMLP, Power, Heritage, and Corporate. The Coal - U.S. reporting segment includes the operations of coal mines located in Montana, North Dakota, Ohio and Texas. The Coal - Canada reporting segment includes the operations of coal mines located in Alberta and Saskatchewan. The Coal - WMLP reporting segment includes the operations of Westmoreland Resource Partners, LP, a publicly-traded coal master limited partnership. The Kemmerer Drop was completed on August 1, 2015 and, accordingly, to enable comparability, all segment disclosures have been adjusted to remove financial information for Kemmerer from the Coal - U.S. segment and present it in the Coal - WMLP segment for all periods presented. The Power segment includes its ROVA operations located in North Carolina. The Heritage segment costs primarily include benefits the Company provides to former mining operation employees as well as other administrative costs associated with providing those benefits and cost containment efforts. The Corporate segment primarily consists of corporate administrative expenses and includes eliminations for intersegment revenues and cost of sales. Summarized financial information by segment is as follows: Coal - U.S. (1)(2) Coal - Canada Coal - WMLP Power (6) Heritage Corporate (7) Consolidated (In thousands) December 31, 2015 Revenues $ 544,172 $ 430,519 $ 388,605 $ 84,423 $ — $ (36,671 ) $ 1,411,048 Restructuring charges — — 656 — — — 656 Depreciation, depletion, and amortization 37,507 29,629 54,504 9,908 — (57 ) 131,491 Operating income (loss) 12,107 40,291 (5,211 ) (146,868 ) (15,596 ) (17,064 ) (132,341 ) Total assets 520,467 506,139 420,907 39,762 16,146 (1,025 ) 1,502,396 Capital expenditures 25,193 27,658 27,296 1,408 — (3,634 ) 77,921 December 31, 2014 Revenues $ 471,567 $ 388,664 $ 170,508 $ 85,253 $ — $ — $ 1,115,992 Restructuring charges 1,058 9,565 2,783 459 78 1,046 14,989 Depreciation, depletion, and amortization 37,651 36,068 16,912 9,998 — 149 100,778 Operating income (loss) (5,078 ) (2,670 ) 26,478 (35,023 ) (14,858 ) (11,824 ) (42,975 ) Total assets 475,999 626,620 482,379 172,104 15,969 43,424 1,816,495 Capital expenditures 23,108 19,147 7,489 527 — 55 50,326 December 31, 2013 Revenues $ 414,652 $ — $ 172,467 $ 87,567 $ — $ — $ 674,686 Restructuring charges — — — 5,078 — — 5,078 Depreciation, depletion, and amortization 38,956 — 17,742 10,179 — 354 67,231 Operating income (loss) 15,744 — 28,726 4,908 (14,498 ) (9,518 ) 25,362 Total assets 511,675 — 194,141 180,684 15,497 39,333 941,330 Capital expenditures 21,045 — 6,019 790 — 737 28,591 ____________________ (1) The Buckingham Acquisition was completed on January 1, 2015. For the year ended December 31, 2015, revenues for Buckingham were $80.4 million and operating losses were $3.2 million . (2) Financial information of the Kemmerer mine for the year ended December 31, 2014 and 2013 was previously presented under the Coal - U.S. segment and is now presented under the Coal - WMLP segment for all periods presented due to the Kemmerer Drop that occurred on August 1, 2015. (3) The Canadian operations were acquired on April 28, 2014, therefore, information for the year ended December 31, 2014 includes approximately eight months of operations and there is no activity for 2013. (4) The Ohio operations reported under the segment Coal - WMLP were acquired on December 31, 2014. For the year ended December 31, 2015, revenues for the Ohio operations were $225.2 million and operating losses were $26.8 million . (5) The Coal - WMLP segment recorded revenues of $30.9 million for intersegment revenues to the Coal - U.S. segment for the year ended December 31, 2015. (6) Operating income (loss) for the Power segment for 2015 includes an impairment charge of $133.1 million . (7) Eliminations for intersegment revenues and cost of sales are presented within the Corporate segment. A reconciliation of segment operating income (loss) to loss before income taxes follows: Years Ended December 31, 2015 2014 2013 (In thousands) Operating income (loss) $ (132,341 ) $ (42,975 ) $ 25,362 Interest expense (104,215 ) (84,234 ) (39,937 ) Loss on extinguishment of debt (5,385 ) (49,154 ) (64 ) Interest income 7,993 6,400 1,366 Gain (loss) on foreign exchange 3,674 (4,016 ) — Other income 1,740 1,031 364 Loss before income taxes $ (228,534 ) $ (172,948 ) $ (12,909 ) The Company derives its revenues from a few key customers. The customers from which more than 10% of total revenue has been derived and the percentage of total revenue from those customers is summarized as follows: December 31, 2015 (1) December 31, 2014 (1) December 31, 2013 (In thousands) Customer A – Coal - U.S. and WMLP $ 203,942 $ — $ — Customer B – Coal - Canada 180,660 144,863 — Customer C – Coal - U.S. 153,585 128,104 117,545 Customer D – Coal - U.S. and WMLP 103,752 101,778 112,061 Customer E – Coal - U.S. 97,449 100,234 89,266 Customer F – Power 84,423 85,254 86,390 Customer G – Coal - U.S. 67,475 79,505 85,929 Percentage of total revenue 63 % 57 % 73 % ____________________ (1) The revenue from Customers D, E, F, and G did not exceed 10% in 2015 and 2014.

QUARTERLY FINANCIAL DATA (UNAUD

QUARTERLY FINANCIAL DATA (UNAUDITED)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
QUARTERLY FINANCIAL DATA (UNAUDITED)	20. QUARTERLY FINANCIAL DATA (UNAUDITED) Summarized quarterly financial data is as follows: Three Months Ended March 31 June 30 September 30 December 31 (1) (In thousands; except per share data) 2015: Revenues $ 371,483 $ 348,959 $ 349,796 $ 340,810 Operating income (loss) 8,455 (6,866 ) (15,307 ) (118,623 ) Net loss applicable to common shareholders (11,732 ) (36,605 ) (46,562 ) (108,418 ) Basic loss per common share $ (0.67 ) $ (2.04 ) $ (2.59 ) $ (6.00 ) 2014: Revenues $ 180,202 $ 287,956 $ 337,830 $ 310,004 Operating income (loss) 8,053 (29,640 ) (29,432 ) 8,044 Net loss applicable to common shareholders (19,291 ) (63,363 ) (49,329 ) (41,135 ) Basic loss per common share $ (1.30 ) $ (4.19 ) $ (2.95 ) $ (2.41 ) ____________________ (1) Operating income (loss) for the three months ended December 31, 2015 includes $136.2 million of impairment charges at ROVA and the Coal Valley mine in the Coal - Canada segment. The Canadian Acquisition was completed on April 28, 2014; therefore, operating results includes activities of the Canadian operations beginning with the three months ended June 30, 2014. The WMLP Transactions were completed December 31, 2014; therefore, operating results includes activities of the Ohio operations beginning with the three months ended March 31, 2015. Additionally, the Buckingham Acquisition was completed January 1, 2015; therefore, operating results includes activities of the Buckingham operations beginning with the three months ended March 31, 2015.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	21. SUBSEQUENT EVENTS Acquisition of San Juan On January 31, 2016, Westmoreland San Juan, LLC (“WSJ”), a special purpose subsidiary of Westmoreland, acquired San Juan Coal Company (“SJCC”), which operates the San Juan mine in Farmington, New Mexico, and San Juan Transportation Company (together with SJCC, the “San Juan Entities” and such transaction, the “Acquisition”) for a total cash purchase price of approximately $127 million , subject to post-closing adjustments. The San Juan mine is the exclusive supplier of coal to the adjacent San Juan Generating Station (“SJGS”) under a coal supply agreement with tonnage and pricing adjusting quarterly through 2022. WSJ financed the Acquisition with a $125 million loan from NM Capital Utility Corporation, an affiliate of Public Service Company of New Mexico (one of the owners of SJGS), and with available cash on hand. The loan is structured as a senior secured term loan (the “Loan”) maturing February 1, 2021 and is expected to bear interest at a (i) 7.25% rate (the “Margin Rate”) plus (ii) (A) the London Interbank Offered Rate for a three month period plus (B) a statutory reserve rate, which such Margin Rate increases incrementally during each year of the Loan term. The Loan has no prepayment penalties. The agreements governing the Loan include representations and warranties and covenants regarding the ownership and operation of SJCC and the properties acquired in the Acquisition and standard special purpose bankruptcy remote entity covenants designed to preserve the separateness from Westmoreland of each of (i) WSJ, (ii) its direct parent company, Westmoreland San Juan Holdings, Inc., and (iii) SJCC (collectively, the “Westmoreland San Juan Entities”). Obligations under the Loan are recourse only to the Westmoreland San Juan Entities and their assets and neither Westmoreland nor its subsidiaries (other than the Westmoreland San Juan Entities) is an obligor under the Loan in any respect. The agreement governing the Loan requires that all revenues of the San Juan Entities, aside from payments on certain leases, are deposited into a cash management collection account swept monthly for operating expenses, capital expenditures, and Loan payment and prepayment.

SUMMARY OF SIGNIFICANT ACCOUN29

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Consolidation Policy	The Consolidated Financial Statements of Westmoreland Coal Company include the accounts of the Company and its controlled subsidiaries. The Company provides for noncontrolling interests in consolidated subsidiaries in which the Company’s ownership is less than 100%. All intercompany accounts and transactions have been eliminated. Investments in unconsolidated affiliates that the Company has the ability to exercise significant influence over, but not control, are accounted for under the equity method of accounting. Under the equity method of accounting, the Company records its proportionate share of the entity’s net income or loss at each reporting period in Income from equity affiliates on the Consolidated Statements of Operations with a corresponding entry to increase or decrease the carrying value of the investment.
Use of Estimates	The preparation of financial statements in conformity with Generally Accepted Accounting Principles (“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.
Cash and Cash Equivalents	Cash and cash equivalents are stated at cost, which approximate fair value. Cash equivalents consist of highly liquid investments with original maturities of three months or less.
Trade Receivables	Trade receivables are recorded at the invoiced amount and generally do not bear interest. The Company evaluates the need for an allowance for doubtful accounts based on a review of collectability.
Loan and Lease Receivables	The Company periodically executes loans and finance leases at the Genesee Mine with its only customer for purposes of funding capital expenditures and working capital requirements. Finance lease and loan receivables are measured at the present value of the future lease payments at the inception of the arrangement. Lease payments received are comprised of a repayment of principal and finance income. Finance income is recognized based on the interest rate implicit in the finance lease. We recognize finance income over periods between three and twenty-seven years , which reflect a constant periodic return on our net investment in the finance lease. Initial direct costs are included in the initial measurement of the finance lease receivables and reduce the amount of income recognized over the lease term.
Inventories	Inventories include materials and supplies, which are carried at historical cost less an obsolescence reserve when necessary, and raw coal, which is carried at the lower of cost or market. Cost of coal is determined using the average cost method and includes labor, supplies, equipment, depreciation, depletion, amortization, operating overhead and other related costs.
Exploration and Mine Development	Exploration expenditures are charged to Cost of sales as incurred, including costs related to drilling and study costs incurred to convert or upgrade mineral resources to reserves. At existing surface operations, additional pits may be added to increase production capacity in order to meet customer requirements. These expansions may require significant capital to purchase additional equipment, relocate equipment, build or improve existing haul roads and create the initial pre-production box cut to remove overburden for new pits at existing operations. 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 Company 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 and includes long-term spare parts inventory. 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. Coal reserves, mineral rights and mine development costs are depleted based upon estimated recoverable proven and probable reserves. Long-term spare parts inventory begins depreciation when placed in service. Plant and equipment are depreciated on a straight-line basis over the assets’ estimated useful lives as follows: Years Buildings and improvements 5 to 40 Machinery and equipment 1 to 36 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 is not eliminated from the accounts.
Impairment of Long-Lived Assets	The Company evaluates its long-lived assets held and used in operations for impairment as events and changes in circumstances indicate that the carrying amount of such assets might not be recoverable. Factors that would indicate potential impairment to be present include, but are not limited to, a sustained history of operating or cash flow losses, an unfavorable change in earnings and cash flow outlook, prolonged adverse industry or economic trends and a significant adverse change in the extent or manner in which a long-lived asset is being used or in its physical condition. Assets are grouped at the lowest level for which there are identifiable cash flows that are largely independent of the cash flows of other groups of assets. Coal mining assets are generally grouped at the mine level, and our ROVA operations also constitute an asset group. When indicators of impairment are present, the Company evaluates its long-lived assets for recoverability by comparing the estimated undiscounted cash flows expected to be generated by those assets under various assumptions to their carrying amounts. If such undiscounted cash flows indicate that the carrying value of the asset group is not recoverable, impairment losses are measured by comparing the estimated fair value of the asset group to its carrying amount. Fair value is generally determined through the use of an expected present value technique based on the income approach. The estimated future cash flows and underlying assumptions used to assess recoverability and, if necessary, measure the fair value of the Company's long-lived asset groups are derived from those developed in connection with the Company's planning and budgeting process. Our estimated future cash flows for our ROVA asset group also utilize projected power prices in addition to the estimated cash flows developed by our planning and budgeting process. The Company believes its assumptions to be consistent with those a market participant would use for valuation purposes.
Reclamation Deposits and Contractual Third-Party Reclamation Receivables	Certain of the Company’s customers have either agreed to reimburse the Company for reclamation expenditures as they are incurred or have pre-funded a portion of the expected reclamation costs. Amounts received from customers and held on deposit are recorded as reclamation deposits. Amounts that are reimbursable by customers are recorded as third-party reclamation receivables when the related reclamation obligation is recorded.
Derivatives and Financial Instruments	The Company enters into financial derivatives to manage exposure to fluctuations in foreign currency exchange rates and power prices. The Company does not utilize derivative financial instruments for trading purposes or for speculative purposes. The Company’s derivative instruments are recorded at fair value with changes in fair value recognized in the Consolidated Statements of Operations at the end of each period in Gain (loss) on foreign exchange or Derivative loss . The Company evaluates all of its financial instruments to determine if such instruments are derivatives, derivatives that qualify for the normal purchase normal sale exception or instruments that contain features that qualify them as embedded derivatives. Except for derivatives that qualify for the normal purchase normal sale exception, all derivative financial instruments are recognized in the balance sheet at fair value. Changes in fair value are recognized in earnings if they are not eligible for hedge accounting or Accumulated other comprehensive income (loss) if they qualify for cash flow hedge accounting. Held-to-maturity financial instruments consist of non-derivative financial assets with fixed or determinable payments and a fixed term, which the Company has the ability and intent to hold until maturity, and, therefore, accounts for them as held-to-maturity securities. Held-to-maturity securities are recorded at amortized cost, adjusted for the amortization or accretion of premiums or discounts calculated on the effective interest method. Interest income is recognized when earned. The Company has securities classified as available-for-sale, which are recorded at fair value. The changes in fair values are recorded as unrealized gains (losses) as a component of Accumulated other comprehensive income (loss) in shareholders’ deficit. The Company reviews its securities routinely for other-than-temporary impairment. The primary factors used to determine if an impairment charge must be recorded because a decline in value of the security is other than temporary include (i) whether the fair value of the investment is significantly below its cost basis, (ii) the financial condition of the issuer of the security, (iii) the length of time that the cost of the security has exceeded its fair value and (iv) the Company’s intent and ability to retain the investment for a period of time sufficient to allow for any anticipated recovery in market value. Other-than-temporary impairments are recorded as a component of Other income .
Fair Value	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 a given measurement date. Valuation techniques used must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value and is defined as: • Level 1, defined as observable inputs such as quoted prices in active markets for identical assets. Level 1 assets include available-for-sale equity securities generally valued based on independent third-party market prices. • Level 2, defined as observable inputs other than Level 1 prices. These include quoted prices for similar assets or liabilities in an active market, quoted prices for identical assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.
Intangible Assets and Liabilities	Identifiable intangible assets or liabilities acquired in a business combination are recognized and reported separately from goodwill.
Compensation Related Costs	Workers’ Compensation Benefits The Company is self-insured for workers’ compensation claims incurred prior to 1996. The liabilities for workers’ compensation claims are actuarially determined estimates of the ultimate losses incurred based on the Company’s experience. Adjustments to the actuarially determined liability are made annually based on subsequent developments and experience and are included in operations at the time of the revised estimate. The Company insures its current employees through third-party insurance providers and state arrangements. Pneumoconiosis (Black Lung) Benefits The Company is self-insured for federal and state black lung benefits for former heritage employees and has established an independent trust to pay these benefits. The Company accounts for these benefits on the accrual basis. An independent actuary annually calculates the present value of the accumulated black lung obligation. The underfunded status in 2015 and 2014 of the Company’s obligation is included as Excess of black lung benefit obligation over trust assets in the accompanying consolidated balance sheets. Actuarial gains and losses are recognized in the period in which they arise. The Company insures its current represented employees through arrangements with its unions and its current non-represented employees are insured through third-party insurance providers. The Company maintains actuarially determined accruals to account for estimates of the ultimate losses incurred. Postretirement Health Care Benefits The Company accrues the cost to provide the benefits over the employees’ period of active service for postretirement benefits other than pensions. These costs are determined on an actuarial basis. The Company’s consolidated balance sheet reflects the unfunded status of postretirement benefit obligations. Pension and SERP Plans The Company accrues the cost to provide the benefits over the employees’ period of active service for the non-contributory defined benefit pension and SERP plans it sponsors. These costs are determined on an actuarial basis. The Company’s consolidated balance sheet reflects the unfunded status of the defined benefit pension and SERP plans.
Deferred Revenue	Deferred revenues represent funding received in advance of meeting the criteria for revenue recognition. Deferred revenue is recognized as the underlying revenue recognition criteria are met, which often occurs as deliveries of coal or power are made in accordance with long-term contacts.
Asset Retirement Obligations	The Company’s asset retirement obligation, or ARO, liabilities primarily consist of estimated costs to reclaim surface land and support facilities at its mines and power plants in accordance with federal and state reclamation laws as established by each mining permit. The Company estimates its ARO liabilities 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 and are escalated for inflation, and then discounted at a credit-adjusted risk-free rate. The Company records 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 liability 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.
Income Taxes	The Company is subject to income taxes in the U.S. (including federal and state) and certain foreign jurisdictions. Deferred income taxes are provided for temporary differences arising from differences between the financial statement amount and tax basis of assets and liabilities existing at each balance sheet date using enacted tax rates anticipated to be in effect when the related taxes are expected to be paid or recovered. A valuation allowance is established if it is more likely than not (greater than 50%) that a deferred tax asset will not be realized. In determining the need for a valuation allowance at each reporting period, the Company considers projected realization of tax benefits based on expected levels of future taxable income, the duration of statutory carryforward periods, experience with operating loss and tax credit carryforwards not expiring and availability of tax planning strategies. Accounting guidance prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. Under this guidance, a company can recognize the benefit of an income tax position only if it is more likely than not (greater than 50%) that the tax position will be sustained upon tax examination, based solely on the technical merits of the tax position. Guidance is also provided on the derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition. The Company includes interest and penalties related to income tax matters in income tax expense. Deferred tax liabilities and assets are classified as noncurrent in the statement of financial position. The tax effect of pretax income or loss from continuing operations is generally determined by a computation that does not consider the tax effects of items that are not included in continuing operations. The exception to that incremental approach is that all items (for example, items recorded in other comprehensive income, extraordinary items, and discontinued operations) be considered in determining the amount of tax benefit that results from a loss from continuing operations and that shall be allocated to continuing operations.
Deferred Financing Costs	The Company capitalizes 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 Other assets in the accompanying consolidated balance sheets.
Revenue Recognition	Coal Revenues The Company recognizes coal sales revenue at the time title 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 revenue is recognized based on the pricing contained in the contracts in place at the time that title passes. Power Revenues ROVA supplies power it produces and generates revenues from such sales, as well as through the settlement of related purchased power arrangements. A portion of the payment under the power sales agreement is considered to be an operating lease. The Company is recognizing amounts previously invoiced as revenue on a pro rata basis over the remaining term of the power sales agreement. Other Operating Income (Loss) Other operating income in the accompanying Consolidated Results of Operations reflects income from sources other than coal or power revenues. Income from the Company’s Indian Coal Tax Credit monetization transaction is recorded as Other operating income . The Company recognizes other operating income when business interruption losses have been incurred and reimbursement is realized or realizable . Insurance proceeds are included in Net cash provided by operating activities
Share-Based Compensation	Share-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 sales and Selling and administrative expenses in the accompanying consolidated results of operations.
Earnings (Loss) per Share	Basic earnings (loss) per share have been computed by dividing the net income (loss) applicable to common shareholders by the weighted average number of shares of common stock outstanding during each period. Net income (loss) applicable to common shareholders includes the adjustment for net income or loss attributable to the noncontrolling interest. Diluted earnings (loss) per share is computed by including the dilutive effect of common stock that would be issued assuming conversion or exercise of outstanding convertible notes, stock options, stock appreciation rights, restricted stock and warrants. No such items were included in the computation of diluted loss per share for the years ended 2015 , 2014 or 2013 because the Company incurred a loss from operations in each of these periods and the effect of inclusion would have been anti-dilutive. The table below shows the number of shares that were excluded from the calculation of diluted loss per share because their inclusion would be anti-dilutive to the calculation: Years Ended December 31, 2015 2014 2013 (In thousands) Convertible notes and securities — 626 1,093 Restricted stock units, stock options, and SARs 482 537 805 Total shares excluded from diluted shares calculation 482 1,163 1,898
Foreign Currency Transactions and Translations	Amounts held and transactions denominated in foreign currencies other than the operating unit’s functional currency give rise to foreign exchange gains and losses which are included within Gain (loss) on foreign exchange . Foreign Currency Translation The functional currency of the Company’s Canadian operations is the Canadian dollar. The Company’s Canadian operations’ assets and liabilities are translated at period end exchange rates, and revenues and costs are translated using average exchange rates for the period. Foreign currency translation adjustments are reported in Other comprehensive income (loss) .
Reclassifications	Certain amounts in prior periods have been reclassified to conform with the presentation of 2015 , with no effect on previously reported net loss, cash flows or shareholders’ deficit.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In September 2015, the Financial Accounting Standards Board, or FASB, issued Accounting Standard Update (“ASU”) 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments. ASU 2015-16 eliminates the requirement that an acquirer in a business combination account for measurement-period adjustments retrospectively. Instead, an acquirer will recognize a measurement-period adjustment during the period in which it determines the amount of the adjustment. The guidance is effective for public business entities for fiscal years beginning after 15 December 2015, and interim periods within those fiscal years. Early adoption is permitted. We early adopted this guidance during 2015, with no material impact to our financial statements. In November 2015, the FASB issued ASU 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes. ASU 2015-17 simplifies the presentation of deferred income taxes by requiring that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. The guidance is effective for financial statements issued for annual periods beginning after December 15, 2016, and interim periods within those annual periods with early adoption permitted. We elected to early adopt this standard on December 31, 2015 and retrospectively apply the guidance to prior periods to allow for better comparison. This change in accounting principle had the effect of reducing the non-current liability Deferred income taxes by $13.1 million and $5.4 million as of December 31, 2014 and 2013, respectively. The current asset Deferred income taxes was also reduced to zero for each year by the same amounts. Accounting Pronouncements Effective in the Future In May 2014, the FASB issued ASU 2014-09, 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. In April 2015, the FASB agreed to propose a one-year deferral of the revenue recognition standard's effective date. The new guidance is now effective for the interim and annual periods beginning after December 15, 2017; early application is permitted, but not before the original effective date (annual reporting periods beginning after December 15, 2016). We are currently assessing the impact that this standard will have on our consolidated financial statements and plan to adopt the guidance by its effective date. 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. 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. We anticipate expanded going concern related disclosures to address this guidance in the year it becomes effective. In April 2015, the FASB issued ASU 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs, which requires that debt issuance costs related to a recognized liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The new guidance should be applied on a retrospective basis and is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years, with early adoption permitted. Management projects the impact to the financial statements resulting in balance sheet reclassification reducing the Long-term debt, less current installments balance for each of the respective periods upon adoption. In April 2015, the FASB issued ASU 2015-05, Internal-Use Software (Subtopic 350-40): Customer's Accounting for Fees Paid in a Cloud Computing Arrangement, which provides guidance for determining whether a cloud computing arrangement (also referred to as a hosting arrangement) has a software license element and provides guidance on the appropriate accounting treatment. The new guidance should be applied on a retrospective basis. The new guidance is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the effect that adopting this new accounting guidance will have on its consolidated results of operations, cash flows and financial position and does not believe its impact will be material.

SUMMARY OF SIGNIFICANT ACCOUN30

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Estimated useful lives of plant and equipment	Plant and equipment are depreciated on a straight-line basis over the assets’ estimated useful lives as follows: Years Buildings and improvements 5 to 40 Machinery and equipment 1 to 36
Anti-dilutive securities excluded from the calculation of earnings (loss) per share	The table below shows the number of shares that were excluded from the calculation of diluted loss per share because their inclusion would be anti-dilutive to the calculation: Years Ended December 31, 2015 2014 2013 (In thousands) Convertible notes and securities — 626 1,093 Restricted stock units, stock options, and SARs 482 537 805 Total shares excluded from diluted shares calculation 482 1,163 1,898

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	12 Months Ended
	Dec. 31, 2015
Business Acquisition [Line Items]
Summary of pro forma information	The following unaudited pro forma information has been prepared for illustrative purposes only and assumes the acquisition of the GP and the Canadian Acquisition occurred on January 1, 2013. The unaudited pro forma results have been prepared based on estimates and assumptions, which the Company believes are reasonable, however, they are not necessarily indicative of the consolidated results of operations had the acquisitions occurred on January 1, 2013, or of future results of operations. Unaudited pro forma information for 2015 is not presented as a result of all acquired entities being consolidated for the entire year. Year Ended December 31, 2014 2013 (In thousands) Total Revenues As reported $ 1,115,992 $ 674,686 Pro forma (unaudited) $ 1,644,474 $ 1,673,538 Operating Income (Loss) As reported $ (42,975 ) $ 25,362 Pro forma (unaudited) $ (38,827 ) $ 36,097 Net loss applicable to common shareholders As reported $ (173,118 ) $ (6,057 ) Pro forma (unaudited) $ (135,647 ) $ (62,595 ) Net loss per share applicable to common shareholders As reported $ (10.86 ) $ (0.42 ) Pro forma (unaudited) $ (8.51 ) $ (4.32 )
Westmoreland Resources GP, LLC [Member]
Business Acquisition [Line Items]
Summary of purchase consideration and allocation of purchase consideration	The Company has finalized the purchase price allocation for the GP acquisition, summarized as follows (in millions): Purchase Price: Final as of December 31, 2015 Cash paid at closing $ 30.0 Contingent consideration 3.5 Fair value of outstanding WMLP units 10.8 Total purchase consideration $ 44.3 Allocation of purchase price: Assets: Trade receivables and other $ 22.5 Inventories - materials and supplies 7.4 Inventories - coal 6.6 Other current assets 1.3 Total current assets 37.8 Land and mineral rights 40.2 Plant and equipment 134.0 Advanced coal royalties 9.2 Restricted investments and bond collateral 10.6 Intangible assets 31.0 Other assets 0.2 Total Assets 263.0 Liabilities: Trade payables and other accrued liabilities (19.1 ) Asset retirement obligations (7.8 ) Other current liabilities (4.0 ) Total current liabilities (30.9 ) Long-term debt, less current installments (160.1 ) Asset retirement obligations, less current portion (23.9 ) Warrants (2.0 ) Other liabilities (1.8 ) Total Liabilities (218.7 ) Net Assets 44.3 Non-controlling Interest (10.8 ) Invested Equity $ 33.5
Canadian Acquisition [Member]
Business Acquisition [Line Items]
Summary of purchase consideration and allocation of purchase consideration	The Company has finalized the purchase price allocation for the Canadian Acquisition, summarized as follows (in millions): Purchase Price: Final as of December 31, 2014 Cash paid - Initial payment $ 282.8 Cash paid - Working capital adjustment 39.8 Total cash consideration $ 322.6 Allocation of purchase price: Assets: Cash and cash equivalents $ 26.2 Receivables 78.1 Inventories - materials and supplies 52.0 Inventories - coal 79.8 Loan and lease receivables 11.2 Deferred tax assets 8.2 Other current assets 3.4 Total current assets 258.9 Land and mineral rights 202.6 Plant and equipment 114.8 Loan and lease receivables 79.1 Contractual third-party reclamation receivables, less current portion 6.8 Investment in joint venture 36.0 Intangible assets 37.0 Other assets 8.7 Total Assets 743.9 Liabilities: Current installments of long-term debt (36.3 ) Trade payables and other accrued liabilities (136.1 ) Asset retirement obligations (7.8 ) Total current liabilities (180.2 ) Long-term debt, less current installments (86.3 ) Asset retirement obligations, less current portion (122.9 ) Deferred tax liabilities (31.9 ) Total Liabilities (421.3 ) Net fair value $ 322.6

INVENTORIES (Tables)

INVENTORIES (Tables)	12 Months Ended
	Dec. 31, 2015
Inventory Disclosure [Abstract]
Inventories	Inventories consisted of the following: December 31, 2015 2014 (In thousands) Coal stockpiles $ 38,636 $ 41,795 Coal fuel inventories 7,194 6,531 Materials and supplies 78,784 88,584 Reserve for obsolete inventory (2,756 ) (3,055 ) Total $ 121,858 $ 133,855

RESTRICTED INVESTMENTS AND BO33

RESTRICTED INVESTMENTS AND BOND COLLATERAL (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure Restricted Investments and Bond Collateral [Abstract]
Components of restricted investments and bond collateral	The Company’s restricted investments and bond collateral consist of the following: December 31, 2015 2014 (In thousands) Coal - U.S. Segment: Reclamation bond collateral: Absaloka Mine $ 11,810 $ 11,781 Colstrip Mine 3,145 3,145 Beulah Mine 1,270 1,270 Buckingham acquisition escrow — 34,000 Coal - Canada Segment: Reclamation bond collateral - PMRU 18,228 18,199 Reclamation bond collateral - CVRI 33,872 31,866 Coal - WMLP Segment: Reclamation bond collateral - Ohio 6,895 10,634 Reclamation bond collateral - Kemmerer Mine 27,631 25,282 Power Segment: Power contract collateral 22,200 12,600 Corporate Segment: Postretirement medical benefit bond collateral 8,897 8,780 Workers’ compensation bond collateral 6,856 6,832 Total restricted investments and bond collateral $ 140,804 $ 164,389
Carrying value and estimated fair value of restricted investments and bond collateral	The Company’s carrying value and estimated fair value of its restricted investments and bond collateral at December 31, 2015 are as follows: Carrying Value Fair Value (In thousands) Cash and cash equivalents $ 102,536 $ 102,536 Time deposits 2,455 2,455 Available-for-sale 35,813 35,813 $ 140,804 $ 140,804
Cost basis, gross unrealized holding gains and fair value of available-for-sale securities	Available-for-sale restricted investments and bond collateral were as follows: December 31, 2015 2014 (In thousands) Cost basis $ 36,715 $ 33,879 Gross unrealized holding gains 167 761 Gross unrealized holding losses (1,069 ) (583 ) Fair value $ 35,813 $ 34,057
Maturities of available-for-sale	Maturities of available-for-sale securities were as follows at December 31, 2015 : Amortized Cost Fair Value (In thousands) Due within one year $ 1,127 $ 1,057 Due in five years or less 15,522 14,896 Due after five years to ten years 5,142 4,939 Due in more than ten years 14,924 14,921 $ 36,715 $ 35,813 Maturities of available-for-sale securities are as follows at December 31, 2015 : Cost Fair Value (In thousands) Within one year $ 592 $ 529 Due in five years or less 16,156 16,049 Due after five years to ten years 6,207 5,925 Due in more than ten years 9,022 9,042 $ 31,977 $ 31,545

INTANGIBLE ASSETS AND LIABILI34

INTANGIBLE ASSETS AND LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of Intangible Assets and Liabilities [Table Text Block]	The estimated amortization amounts from intangibles assets and liabilities for each of the next five years as of December 31, 2015 are as follows: Amount of Amortization to Recognize in Revenues Amount of Amortization to Recognize in Cost of Sales (In thousands) 2016 $ 1,068 $ 2,130 2017 1,068 2,130 2018 1,068 2,130 2019 267 2,105 2020 — 2,096

RESTRUCTURING CHARGES (Tables)

RESTRUCTURING CHARGES (Tables)	12 Months Ended
	Dec. 31, 2015
ROVA Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Costs	The table below represents the restructuring provision activity related to the restructuring plans (in millions): ROVA Restructuring Plan Acquisition Restructuring Plans Total Balance, December 31, 2013 $ 5.1 $ — $ 5.1 Restructuring Charges 0.5 14.5 15.0 Cash Payments (5.2 ) (5.7 ) (10.9 ) Balance, December 31, 2014 0.4 8.8 9.2 Restructuring Charges — 0.7 0.7 Cash Payments (0.4 ) (8.6 ) (9.0 ) Balance, December 31, 2015 $ — $ 0.9 $ 0.9

LINES OF CREDIT AND LONG-TERM36

LINES OF CREDIT AND LONG-TERM DEBT (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Outstanding lines of credit and long-term debt	The amounts outstanding under the Company’s long-term debt consisted of the following as of the dates indicated: Total Debt Outstanding December 31, 2015 2014 (In thousands) 8.75% Notes $ 350,000 $ 350,000 WCC Term Loan Facility 327,172 350,000 WMLP Term Loan Facility 299,248 175,000 Capital lease obligations 71,168 109,351 Revolving line of credit 1,970 9,576 Other 7,251 4,062 Debt discount (11,095 ) (13,202 ) Total debt outstanding 1,045,714 984,787 Less current installments (40,822 ) (52,712 ) Total debt outstanding, less current installments $ 1,004,892 $ 932,075
Aggregate contractual debt maturities of all long-term debt and lines of credit	The following table presents aggregate contractual debt maturities of all long-term debt: As of December 31, 2015 (In thousands) 2016 $ 40,822 2017 31,846 2018 11,094 2019 307,733 2020 315,314 Thereafter 350,000 Total 1,056,809 Less: debt discount (11,095 ) Total debt $ 1,045,714

POSTRETIREMENT MEDICAL BENEFI37

POSTRETIREMENT MEDICAL BENEFITS (Tables)	12 Months Ended
	Dec. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of contributions to Combined Benefit Fund	The following payments were made to the CBF (in millions): 2015 $ 1.8 2014 2.0 2013 2.2
Schedule of Workers Compensation obligation	The following table shows the changes in the Company’s workers’ compensation obligation: December 31, 2015 2014 (In thousands) Workers’ compensation, beginning of year (including current portion) $ 6,986 $ 7,461 Accretion 127 200 Claims paid (448 ) (405 ) Actuarial changes (1,007 ) (270 ) Workers’ compensation, end of year 5,658 6,986 Less current portion, included in Other current liabilities (590 ) (671 ) Workers’ compensation, less current portion $ 5,068 $ 6,315
Postretirement Medical Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of benefit obligations and amounts recognized in financial statements	The following table sets forth the actuarial present value of postretirement medical benefit obligations and amounts recognized in the Company’s financial statements: December 31, 2015 2014 (In thousands) Change in benefit obligations: Net benefit obligation at beginning of year $ 306,418 $ 284,329 Service cost 4,217 3,289 Interest cost 11,629 12,814 Plan participant contributions 185 149 Actuarial loss (gain) (7,322 ) 19,441 Gross benefits paid (17,013 ) (14,860 ) Federal subsidy on benefits paid 1,259 1,256 Net benefit obligation at end of year 299,373 306,418 Change in plan assets: Employer contributions 16,828 14,711 Plan participant contributions 185 149 Gross benefits paid (17,013 ) (14,860 ) Fair value of plan assets at end of year — — Unfunded status at end of year $ (299,373 ) $ (306,418 ) Amounts recognized in the balance sheet consist of: Current liabilities $ (13,855 ) $ (13,263 ) Noncurrent liabilities (285,518 ) (293,156 ) Accumulated other comprehensive loss 31,085 39,716 Net amount recognized $ (268,288 ) $ (266,703 ) Amounts recognized in accumulated other comprehensive loss consists of: Net actuarial loss $ 35,534 $ 44,800 Prior service credit (4,449 ) (5,084 ) $ 31,085 $ 39,716
Schedule of amounts in Accumulated Other Comprehensive Income (Loss) to be recognized over next fiscal year	The following amounts will be amortized from accumulated other comprehensive loss into net periodic benefit cost in 2016 (in millions): Actuarial loss $ 1.4 Prior service credit (0.6 )
Components of net periodic benefit cost	The components of net periodic postretirement medical benefit cost are as follows: Years Ended December 31, 2015 2014 2013 (In thousands) Components of net periodic benefit cost: Service cost $ 4,217 $ 3,289 $ 4,436 Interest cost 11,629 12,814 12,139 Amortization of: Prior service credit (636 ) (635 ) (636 ) Actuarial loss 1,944 653 4,641 Total net periodic benefit cost $ 17,154 $ 16,121 $ 20,580 The following table shows the net periodic postretirement medical benefit costs that relate to current and former mining operations: Years Ended December 31, 2015 2014 2013 (In thousands) Former mining operations $ 8,137 $ 9,614 $ 12,475 Current operations 9,017 6,507 8,105 Total net periodic benefit cost $ 17,154 $ 16,121 $ 20,580
Schedule of weighted-average assumptions used	The weighted-average assumptions used to determine the benefit obligations as of the end of each year were as follows: December 31, 2015 2014 Discount rate 4.10% - 4.65% 3.75% - 4.25% Measurement date December 31, 2015 December 31, 2014 The weighted-average assumptions used to determine net periodic benefit cost were as follows: December 31, 2015 2014 2013 Discount rate 3.75% - 4.25% 4.50% - 5.05% 3.60% - 4.15% Measurement date December 31, 2014 December 31, 2013 December 31, 2012
Schedule of assumed health care trend rate	The following presents information about the assumed health care trend rate: December 31, 2015 2014 Health care cost trend rate assumed for next year 7.00 % 6.50 % Rate to which the cost trend is assumed to decline (ultimate trend rate) 4.75 % 5.00 % Year that the trend rate reaches the ultimate trend rate 2025 2021
Schedule of effect of a one percent change on the health care cost trend	The effect of a one percent change on the health care cost trend rate used to calculate periodic postretirement medical benefit costs and the related benefit obligation are summarized in the table below: Postretirement Medical Benefits 1 % Increase 1 % Decrease (In thousands) Effect on service and interest cost components $ 3,235 $ (2,444 ) Effect on postretirement medical benefit obligation $ 41,360 $ (33,667 )
Schedule of expected benefit payments	The following benefit payments and Medicare D subsidy (which the Company receives as a benefit partially offsetting its prescription drug costs for retirees and their dependents) are expected by the Company: Postretirement Medical Benefits Medicare D Subsidy Net Postretirement Medical Benefits (In thousands) 2016 $ 13,855 $ (1,388 ) $ 12,467 2017 14,250 (1,457 ) 12,793 2018 14,744 (1,516 ) 13,228 2019 15,205 (1,573 ) 13,632 2020 15,627 (1,623 ) 14,004 Years 2021 - 2025 82,997 (8,830 ) 74,167
Pneumoconiosis (Black Lung) Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of net funded status	The following table sets forth the funded status of the Company’s black lung obligation: December 31, 2015 2014 (In thousands) Actuarial present value of benefit obligation: Expected claims from terminated employees $ 2,472 $ 953 Amounts owed to existing claimants 15,318 13,054 Total present value of benefit obligation 17,790 14,007 Plan assets at fair value 570 2,755 Excess of the black lung benefit obligation over trust assets $ 17,220 $ 11,252
Schedule of allocation of plan assets	The fair value of the Company’s Black Lung trust assets by asset category is as follows: Fair Value as of December 31, 2015 December 31, 2014 (In thousands) U.S. treasury securities $ 256 $ 2,615 Cash and cash equivalents 314 140 $ 570 $ 2,755

PENSION AND OTHER SAVING PLANS

PENSION AND OTHER SAVING PLANS (Tables) - Pension Benefits [Member]	12 Months Ended
	Dec. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of benefit obligations and amounts recognized in financial statements	The following table provides a reconciliation of the changes in the benefit obligations of the plans and the fair value of assets of the qualified plans and the amounts recognized in the Company’s financial statements for both the defined benefit pension and SERP plans: Defined Benefit Pension December 31, SERP December 31, 2015 2014 2015 2014 (In thousands) Change in benefit obligation: Net benefit obligation at beginning of year $ 206,966 $ 155,075 $ 4,129 $ 3,640 Liability acquired — 36,087 — — Service cost 1,760 2,425 — — Interest cost 7,282 7,963 153 168 Actuarial loss (gain) (11,514 ) 32,505 (108 ) 704 Benefits and expenses paid (17,974 ) (15,119 ) (372 ) (383 ) Settlements and curtailments (1,559 ) (10,862 ) — — Plan amendments — 207 — — Foreign currency exchange rate changes (3,532 ) (1,315 ) — — Net benefit obligation at end of year 181,429 206,966 3,802 4,129 Change in plan assets: Fair value of plan assets at the beginning of year 160,947 134,149 — — Assets acquired — 36,616 — — Actual return on plan assets (2,379 ) 14,392 — — Employer contributions 3,727 4,812 372 383 Benefits and expenses paid (17,974 ) (15,119 ) (372 ) (383 ) Settlements 124 (12,795 ) — — Foreign currency exchange rate changes (3,308 ) (1,108 ) — — Fair value of plan assets at end of year 141,137 160,947 — — Unfunded status at end of year $ (40,292 ) $ (46,019 ) $ (3,802 ) $ (4,129 ) Amounts recognized in the accompanying balance sheet consist of: Noncurrent asset, included in Other assets $ 1,082 $ — $ — $ — Current liability — — (368 ) (368 ) Noncurrent liability (41,374 ) (46,019 ) (3,434 ) (3,760 ) Accumulated other comprehensive loss 33,313 34,249 1,589 1,815 Net amount recognized at end of year $ (6,979 ) $ (11,770 ) $ (2,213 ) $ (2,313 ) Amounts recognized in accumulated other comprehensive loss consist of: Net actuarial loss $ 33,236 $ 34,164 $ 1,589 $ 1,815 Prior service cost 77 85 — — $ 33,313 $ 34,249 $ 1,589 $ 1,815
Schedule of amounts in Accumulated Other Comprehensive Income (Loss) to be recognized over next fiscal year	The following amounts will be amortized from accumulated other comprehensive loss into net periodic benefit cost in 2016 (in millions): Pension SERP Net actuarial loss $ 5.6 $ 0.1
Components of net periodic benefit cost	The components of net periodic benefit cost are as follows: Defined Benefit Pension Years Ended December 31, SERP Years Ended December 31, 2015 2014 2013 2015 2014 2013 (In thousands) Components of net periodic benefit cost: Service cost $ 1,760 $ 2,425 $ 2,346 $ — $ — $ — Interest cost 7,282 7,963 6,209 153 168 152 Expected return on plan assets (10,033 ) (10,796 ) (8,770 ) — — Settlements and curtailments (1,683 ) 4,585 — — — — Amortization of: Prior service cost 8 — — — — — Actuarial loss 2,840 1,217 3,377 118 97 112 Total net periodic pension cost $ 174 $ 5,394 $ 3,162 $ 271 $ 265 $ 264
Schedule of weighted-average assumptions used	The weighted-average assumptions used to determine the benefit obligations as of the end of each year were as follows: Defined Benefit Pension December 31, SERP December 31, 2015 2014 2015 2014 Discount rate 3.90% - 4.25% 3.60% - 3.90% 4.25% 3.90% Measurement date December 31, 2015 December 31, 2014 December 31, 2015 December 31, 2014 The following table provides the assumptions used to determine net periodic benefit cost: Defined Benefit Pension Years Ended December 31, SERP Years Ended December 31, 2015 2014 2013 2015 2014 2013 Discount rate 3.60% - 3.90% 4.25% - 4.70% 3.35% - 3.75% 3.90% 4.65% 3.75% Expected return on plan assets 3.66% - 7.10% 7.40% 7.40% N/A N/A N/A Rate of compensation increase N/A N/A N/A N/A N/A N/A Measurement date December 31, 2014 December 31, 2013 December 31, 2012 December 31, 2014 December 31, 2013 December 31, 2012
Schedule of allocation of plan assets	The weighted-average target asset allocation of the Company’s pension trusts were as follows at December 31, 2015 : Target Allocation Asset category Cash and equivalents 0% - 10% Equity securities funds 20% - 60% Debt securities funds 40% - 80% Other 0% - 10% The fair value of the Company’s pension plan assets by asset category is as follows: December 31, 2015 Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Fair Value Level 1 Level 2 Level 3 (In thousands) Pooled separate accounts: Large-cap blend (a) $ 43,417 $ — $ 43,417 $ — International blend (b) 7,779 — 7,779 — Fixed income domestic (c) 22,115 — 22,115 — Fixed income long term (d) 43,091 — 43,091 — Stable value (e) 4,937 — 4,937 — Registered investment companies – growth fund 15,447 15,447 — — Limited partnerships and limited liability companies 136 — — 136 Westmoreland Coal common stock 273 273 — — Cash and cash equivalents 3,942 3,942 — — $ 141,137 $ 19,662 $ 121,339 $ 136 December 31, 2014 Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Fair Value Level 1 Level 2 Level 3 (In thousands) Pooled separate accounts: Large-cap blend (a) $ 47,092 $ — $ 47,092 $ — International blend (b) 7,290 — 7,290 — Fixed income domestic (c) 23,057 — 23,057 — Fixed income long term (d) 47,299 — 47,299 — Stable value (e) 5,346 — 5,346 — Registered investment companies – growth fund 16,490 16,490 — — Limited partnerships and limited liability companies 224 — — 224 Westmoreland Coal common stock 1,539 1,539 — — Cash and cash equivalents 12,610 12,610 — — $ 160,947 $ 30,639 $ 130,084 $ 224 (a) Large-cap blend funds seek to provide long-term growth of capital. They seek to provide investment results that approximate the performance of the Standard & Poor’s Composite 1500 Index. (b) International blends seek to have a diversified portfolio of investments, invading fixed-income and equity-focused investments in international markets. (c) Fixed income domestic funds seek to invest in high-quality corporate bonds with over 15 years to maturity. (d) Fixed income long term bond funds seek to achieve performance results similar to the Barclays Capital U.S. Aggregate Bond Index. This fund invests primarily in corporate and government bonds. (e) The stable value fund seeks to invest in publicly traded and privately placed debt securities and mortgage loans, and to a lesser extent, real estate and other equity investments in order to provide a guaranteed rate of return.
Schedule of expected benefit payments	The following benefit payments are expected to be paid from its pension plan assets: Pension Benefits (In thousands) 2016 $ 10,846 2017 9,048 2018 9,280 2019 9,758 2020 10,111 Years 2021 - 2025 54,006
Schedule of multiemployer plans	The following table shows required information for each employer contributing to the Central Pension Fund: WECO WRI WSC Employer plan number 9313 9243 4990 Minimum contributions per hour worked $5.85 - $5.90 $4.03 - $4.39 $ 3.70 Expiration date of collective bargaining agreements 2/28/2019 5/31/2021 3/31/2022 Employer contributions (in millions): 2015 $ 3.6 $ 1.1 $ 0.1 2014 3.3 1.2 0.1 2013 3.4 0.9 0.1

HERITAGE HEALTH BENEFIT EXPEN39

HERITAGE HEALTH BENEFIT EXPENSES (Tables)	12 Months Ended
	Dec. 31, 2015
Heritage Health Benefit Expenses [Abstract]
Components of costs of benefits to former mining operation employees	The components of these expenses are as follows: Years Ended December 31, 2015 2014 2013 (In thousands) Health care benefits $ 8,179 $ 9,473 $ 12,579 Combined benefit fund payments 1,794 1,966 2,240 Workers’ compensation benefits (credit) (583 ) 230 (1,212 ) Black lung benefits (credit) 5,183 1,719 (189 ) Total $ 14,573 $ 13,388 $ 13,418

ASSET RETIREMENT OBLIGATIONS,40

ASSET RETIREMENT OBLIGATIONS, CONTRACTUAL THIRD-PARTY RECLAMATION RECEIVABLES, AND RECLAMATION DEPOSITS (Tables)	12 Months Ended
	Dec. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]
Summary of asset retirement obligations, contractual third-party reclamation receivables and reclamation deposits	The asset retirement obligations (“ARO”), contractual third-party reclamation receivables, and reclamation deposits at December 31, 2015 are summarized below: Asset Retirement Obligations Contractual Third-Party Reclamation Receivables Reclamation Deposits (In thousands) Coal - U.S. $ 251,116 $ 89,408 $ 77,364 Coal - Canada 110,978 5,527 — Coal - WMLP 56,634 — — Power 1,035 — — Total $ 419,763 $ 94,935 $ 77,364
Changes in Company's asset retirement obligations	Changes in the Company’s asset retirement obligations were as follows: Years Ended December 31, 2015 2014 (In thousands) Asset retirement obligations, beginning of year (including current portion) $ 452,745 $ 279,864 Accretion 38,891 31,033 Liabilities settled (30,363 ) (23,935 ) Changes due to amount and timing of reclamation (24,533 ) 10,042 Asset retirement obligations acquired 4,146 162,394 Changes due to foreign currency translation (21,123 ) (6,653 ) Asset retirement obligations, end of year 419,763 452,745 Less current portion (43,950 ) (43,289 ) Asset retirement obligations, less current portion $ 375,813 $ 409,456
Carrying value and estimated fair value of reclamation deposits	The carrying value (which equals estimated fair value) of reclamation deposits at December 31, 2015 are as follows: (In thousands) Cash and cash equivalents $ 45,819 Available-for-sale securities 31,545 $ 77,364
Available for Sale Reclamation Deposits	The cost basis, gross unrealized holding gains and fair value of available-for-sale securities are as follows: December 31, 2015 2014 (In thousands) Cost basis $ 31,977 $ 32,930 Gross unrealized holding gains 521 886 Gross unrealized holding losses (953 ) (428 ) Fair value $ 31,545 $ 33,388
Schedule of maturities of held-to-maturity investments	Maturities of available-for-sale securities were as follows at December 31, 2015 : Amortized Cost Fair Value (In thousands) Due within one year $ 1,127 $ 1,057 Due in five years or less 15,522 14,896 Due after five years to ten years 5,142 4,939 Due in more than ten years 14,924 14,921 $ 36,715 $ 35,813 Maturities of available-for-sale securities are as follows at December 31, 2015 : Cost Fair Value (In thousands) Within one year $ 592 $ 529 Due in five years or less 16,156 16,049 Due after five years to ten years 6,207 5,925 Due in more than ten years 9,022 9,042 $ 31,977 $ 31,545

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The fair value of outstanding derivative instruments not designated as hedging instruments on the accompanying Consolidated Balance Sheets was as follows (in thousands): Derivative Instruments Balance Sheet Location December 31, 2015 December 31, 2014 Contracts to purchase power Other current liabilities $ 13,679 $ 8,265 Contracts to purchase power Other liabilities 23,656 21,103 $ 37,335 $ 29,368 The effect of derivative instruments not designated as hedging instruments on the accompanying Consolidated Statements of Operations was as follows (in thousands): Year Ended December 31, Derivative Instruments Statement of Operations Location 2015 2014 Canadian dollar foreign exchange contracts Gain (loss) on foreign exchange $ — $ (6,209 ) Contracts to purchase power Derivative loss (5,587 ) (31,100 )

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Estimated fair values of Company's debt	The estimated fair value of the Company’s debt with fixed and variable interest rates are as follows: Fixed Interest Rate Variable Interest Rate Carrying Value Fair Value Carrying Value Fair Value (In thousands) (In thousands) December 31, 2015 $ 345,984 $ 213,500 $ 619,341 $ 388,380 December 31, 2014 $ 345,533 $ 348,283 $ 516,300 $ 519,750
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The table below sets forth, by level, the Company’s financial assets and liabilities that are accounted for at fair value on a recurring basis: Balance at December 31, 2015 Quoted Prices in Active Markets for Identical Assets or Liabilities Significant Other Observable Inputs Fair Value Level 1 Level 2 (In thousands) Assets: Available-for-sale investments included in Restricted investments and bond collateral $ 35,813 $ 35,813 $ — Available-for-sale investments included in Reclamation deposits 31,545 31,545 — $ 67,358 $ 67,358 $ — Liabilities: Contracts to purchase power included in Other current liabilities and Other liabilities $ (37,335 ) $ — $ (37,335 ) Warrants issued by WMLP included in Other liabilities (646 ) (646 ) $ (37,981 ) $ (646 ) $ (37,335 ) Balance at December 31, 2014 Quoted Prices in Active Markets for Identical Assets or Liabilities Significant Other Observable Inputs Fair Value Level 1 Level 2 (In thousands) Assets: Available-for-sale investments included in Restricted investments and bond collateral $ 34,057 $ 34,057 $ — Available-for-sale investments included in Reclamation deposits 33,388 33,388 — $ 67,445 $ 67,445 $ — Liabilities: Contracts to purchase power included in Other current liabilities and Other liabilities $ (29,368 ) $ — $ (29,368 ) Warrants issued by WMLP included in Other liabilities (1,981 ) (1,981 ) $ (31,349 ) $ (1,981 ) $ (29,368 )

RESTRICTED STOCK UNITS, STOCK43

RESTRICTED STOCK UNITS, STOCK OPTIONS, AND STOCK APPRECIATION RIGHTS (SARs) (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Compensation cost arising from share-based arrangements	Compensation cost arising from share-based arrangements is shown in the following table: Years Ended December 31, 2015 2014 2013 (In thousands) Recognition of fair value of restricted stock units, stock options and SARs over vesting period; and issuance of stock $ 4,019 $ 4,318 $ 2,967 Contributions of stock to the Company’s 401(k) plan 3,729 1,764 2,355 Total share-based compensation expense $ 7,748 $ 6,082 $ 5,322
Summary of Restricted Stock Unit activity	A summary of restricted stock award activity for the year ended December 31, 2015 is as follows: Units Weighted Average Grant-Date Fair Value Unamortized Compensation Expense (In thousands) Non-vested at December 31, 2014 409,362 $ 15.17 Granted 262,555 $ 28.26 Vested (256,937 ) $ 11.27 Forfeited (60,669 ) $ 11.13 Non-vested at December 31, 2015 354,311 $ 28.44 $ 6,572 (1) ____________________ (1) Expected to be recognized over the next three years . Additional information related to restricted stock units: Years Ended December 31: Weighted Average Grant-Date Fair Value Total Grant- Date Fair Value of Restricted Stock Units that Vested (In thousands) 2015 $ 28.26 $ 2,884 2014 $ 30.67 $ 3,536 2013 $ 11.70 $ 1,689
Summary of Stock Option activity	Information with respect to stock option activity for the year ended December 31, 2015 , is as follows: Stock Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (In years) Aggregate Intrinsic Value (In thousands) Unamortized Compensation Expense (In thousands) Outstanding at December 31, 2014 110,806 $ 22.15 Exercised — Expired (1,500 ) $ 21.40 Outstanding and exercisable at December 31, 2015 109,306 $ 22.16 2.2 $ — $ — Additional information related to stock options: Years Ended December 31: Intrinsic Value of Stock Options Exercised 2015 $ — 2014 $ 11.81 2013 $ —
Summary of Stock Appreciation Rights	Information with respect to SARs granted and outstanding for the year ended December 31, 2015 is as follows: SARs Weighted Average Exercise Price Weighted Average Remaining Contractual Life (In years) Aggregate Intrinsic Value (In thousands) Unamortized Compensation Expense (In thousands) Outstanding at December 31, 2014 16,943 $ 25.44 Exercised — Expired — Outstanding and exercisable at December 31, 2015 16,943 $ 25.44 0.4 $ — $ — Additional information related to SARs: Years Ended December 31: Intrinsic Value of SARs Exercised 2015 $ — 2014 $ 11.50 2013 $ —

STOCKHOLDERS' EQUITY AND ACCU44

STOCKHOLDERS' EQUITY AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Schedule of Noncontrolling Interest Activity	Activity in the noncontrolling interest is summarized as follows (in millions): Beginning Balance as of December 31, 2014 $ 15,261 Change in Parent's ownership (8,279 ) Net loss allocated to noncontrolling interest (5,453 ) Distributions to noncontrolling interest (797 ) Other — Ending Balance as of December 31, 2015 $ 732
Schedule of Accumulated Other Comprehensive Income (Loss)	The following is a summary of accumulated other comprehensive income (loss): Pension and Postretirement Medical Benefits Available for Sale Securities Foreign Currency Translation Adjustment Tax Effect of Other Comprehensive Income Gains Accumulated Other Comprehensive Loss (In thousands) Balance at January 1, 2013 $ (122,246 ) $ 57 $ — $ (26,156 ) $ (148,345 ) 2013 activity 89,699 (57 ) — (4,892 ) 84,750 Balance at December 31, 2013 (32,547 ) — — (31,048 ) (63,595 ) 2014 activity (43,234 ) 413 (17,880 ) — (60,701 ) Balance at December 31, 2014 (75,781 ) 413 (17,880 ) (31,048 ) (124,296 ) 2015 activity 10,137 (1,738 ) (52,021 ) (3,382 ) (47,004 ) Balance at December 31, 2015 $ (65,644 ) $ (1,325 ) $ (69,901 ) $ (34,430 ) $ (171,300 ) Changes in Accumulated Other Comprehensive Loss The following table reflects the changes in accumulated other comprehensive loss by component: Pension Postretirement Available for sale securities Foreign currency translation adjustment Tax effect of other comprehensive income gains Accumulated other comprehensive loss (In thousands) Balance at December 31, 2014 $ (36,065 ) $ (39,716 ) $ 413 $ (17,880 ) $ (31,048 ) $ (124,296 ) Other comprehensive income (loss) before reclassifications (853 ) 7,322 (1,887 ) (52,021 ) (3,382 ) (50,821 ) Amounts reclassified from accumulated other comprehensive loss 2,360 1,308 149 — — 3,817 Balance at December 31, 2015 $ (34,558 ) $ (31,086 ) $ (1,325 ) $ (69,901 ) $ (34,430 ) $ (171,300 )
Reclassification out of Accumulated Other Comprehensive Income	The following table reflects the reclassifications out of accumulated other comprehensive loss for the year ended December 31, 2015 (in thousands): Details about accumulated other comprehensive income (loss) components Amount reclassified from accumulated other comprehensive income (loss) (1) Affected line item in the statement where net income (loss) is presented Available-for sale securities Realized gains and losses on available-for sale securities $ 149 Other income (loss) $ 149 Total Amortization of defined benefit pension items: Prior service costs $ 8 (2) Actuarial losses 2,352 (2) $ 2,360 Total Amortization of postretirement medical items: Prior service costs $ (636 ) (3) Actuarial losses 1,944 (3) $ 1,308 Total ____________________ (1) Amounts in parentheses indicate debits to income/loss. (2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost. (See Note 10 - Pension And Other Saving Plans for additional details) (3) These accumulated other comprehensive income components are included in the computation of net periodic postretirement medical cost. (See Note 9 - Postretirement Medical Benefits for additional details)

INCOME TAX (Tables)

INCOME TAX (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of income (loss) before income tax	The Company’s income (loss) before income taxes is as follows: Years Ended December 31, 2015 2014 2013 (In thousands) United States $ (254,252 ) $ (157,043 ) $ (12,909 ) Foreign 25,718 (15,905 ) — Income (loss) before income taxes $ (228,534 ) $ (172,948 ) $ (12,909 )
Schedule of components of income tax expense (benefit)	Income tax expense (benefit) reflected in the consolidated statement of operations consisted of: Years Ended December 31, 2015 2014 2013 (In thousands) Current: Federal $ — $ — $ (2 ) State 12 120 112 Foreign 1,441 545 — 1,453 665 110 Deferred: Federal (3,295 ) — (4,189 ) State (330 ) — (703 ) Foreign (17,595 ) (433 ) — (21,220 ) (433 ) (4,892 ) Income tax expense (benefit) $ (19,767 ) $ 232 $ (4,782 )
Schedule of effective income tax rate reconciliation	The effective tax rate differs from the U.S. federal statutory rate as follows: Years Ended December 31, 2015 2014 2013 (In thousands) Computed income tax expense (benefit) at statutory rate $ (82,022 ) $ (58,066 ) $ (4,390 ) Tax depletion in excess of basis (5,317 ) (9,273 ) (6,187 ) Non-deductible acquisition costs — 2,979 — Intercompany interest (6,488 ) (4,174 ) 1,167 State and foreign income taxes, net (6,184 ) (9,706 ) 3,696 Change in valuation allowance for net deferred tax assets 132,338 77,771 15 Release of valuation allowance arising from amalgamation (32,635 ) — — Indian coal tax credits (“ICTC”) (13,756 ) (15,205 ) 92 Change in Canadian rate (3,081 ) — — Kemmerer deferred tax asset removal (13,238 ) — — Uncertain tax positions 3,994 — — Other, net 6,622 15,906 825 Income tax expense (benefit) $ (19,767 ) $ 232 $ (4,782 )
Schedule of components of deferred tax assets and liabilities	The tax effects of temporary differences that give rise to the deferred tax assets and deferred tax liabilities are presented below: December 31, 2015 2014 (In thousands) Deferred tax assets: Net operating losses $ 198,216 $ 166,489 Credit carryforwards 62,219 47,872 Investment in WMLP 3,112 1,185 Accrued compensation and benefits 5,847 2,592 Asset retirement obligations 92,889 101,514 Postretirement medical benefit and pension obligations 123,595 124,854 Deferred revenue 13,591 15,841 Black lung accrual 7,405 4,244 Unrealized gain/(loss) on derivatives 14,377 11,078 Canadian resource pool 4,088 6,435 Lease obligations 13,341 23,401 Depreciable capital assets — 6,779 Other 5,896 13,514 Total deferred tax assets 544,576 525,798 Valuation allowance (497,796 ) (406,143 ) Net deferred tax assets 46,780 119,655 Deferred tax liabilities: Property, plant and equipment, differences due to depreciation and amortization $ (26,061 ) $ (113,430 ) Investment in joint venture (6,284 ) (7,324 ) Finance lease receivable (9,446 ) (15,232 ) Deferred reclamation revenue (1,492 ) (1,688 ) Other (3,497 ) (3,750 ) Total deferred tax liabilities (46,780 ) (141,424 ) Net deferred tax asset (liability) $ — $ (21,769 )

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Gross value and accumulated amortization of property, plant and equipment and mine development assets under capital leases	The following shows the gross value and accumulated amortization of property, plant and equipment and mine development assets under capital leases related primarily to the leasing of mining equipment as of December 31: 2015 2014 (In thousands) Gross value $ 65,293 $ 74,203 Accumulated amortization 25,878 21,598
Future minimum capital and operating lease payments	Future minimum capital and operating lease payments as of December 31, 2015 , are as follows: Capital Leases Operating Leases (In thousands) 2016 $ 35,467 $ 12,390 2017 27,695 7,409 2018 6,497 5,488 2019 4,336 4,421 2020 1,297 660 Thereafter — 2,360 Total minimum lease payments 75,292 $ 32,728 Less imputed interest (4,124 ) Present value of minimum capital lease payments $ 71,168

BUSINESS SEGMENT INFORMATION (T

BUSINESS SEGMENT INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Summarized financial information by segment	Summarized financial information by segment is as follows: Coal - U.S. (1)(2) Coal - Canada Coal - WMLP Power (6) Heritage Corporate (7) Consolidated (In thousands) December 31, 2015 Revenues $ 544,172 $ 430,519 $ 388,605 $ 84,423 $ — $ (36,671 ) $ 1,411,048 Restructuring charges — — 656 — — — 656 Depreciation, depletion, and amortization 37,507 29,629 54,504 9,908 — (57 ) 131,491 Operating income (loss) 12,107 40,291 (5,211 ) (146,868 ) (15,596 ) (17,064 ) (132,341 ) Total assets 520,467 506,139 420,907 39,762 16,146 (1,025 ) 1,502,396 Capital expenditures 25,193 27,658 27,296 1,408 — (3,634 ) 77,921 December 31, 2014 Revenues $ 471,567 $ 388,664 $ 170,508 $ 85,253 $ — $ — $ 1,115,992 Restructuring charges 1,058 9,565 2,783 459 78 1,046 14,989 Depreciation, depletion, and amortization 37,651 36,068 16,912 9,998 — 149 100,778 Operating income (loss) (5,078 ) (2,670 ) 26,478 (35,023 ) (14,858 ) (11,824 ) (42,975 ) Total assets 475,999 626,620 482,379 172,104 15,969 43,424 1,816,495 Capital expenditures 23,108 19,147 7,489 527 — 55 50,326 December 31, 2013 Revenues $ 414,652 $ — $ 172,467 $ 87,567 $ — $ — $ 674,686 Restructuring charges — — — 5,078 — — 5,078 Depreciation, depletion, and amortization 38,956 — 17,742 10,179 — 354 67,231 Operating income (loss) 15,744 — 28,726 4,908 (14,498 ) (9,518 ) 25,362 Total assets 511,675 — 194,141 180,684 15,497 39,333 941,330 Capital expenditures 21,045 — 6,019 790 — 737 28,591 ____________________ (1) The Buckingham Acquisition was completed on January 1, 2015. For the year ended December 31, 2015, revenues for Buckingham were $80.4 million and operating losses were $3.2 million . (2) Financial information of the Kemmerer mine for the year ended December 31, 2014 and 2013 was previously presented under the Coal - U.S. segment and is now presented under the Coal - WMLP segment for all periods presented due to the Kemmerer Drop that occurred on August 1, 2015. (3) The Canadian operations were acquired on April 28, 2014, therefore, information for the year ended December 31, 2014 includes approximately eight months of operations and there is no activity for 2013. (4) The Ohio operations reported under the segment Coal - WMLP were acquired on December 31, 2014. For the year ended December 31, 2015, revenues for the Ohio operations were $225.2 million and operating losses were $26.8 million . (5) The Coal - WMLP segment recorded revenues of $30.9 million for intersegment revenues to the Coal - U.S. segment for the year ended December 31, 2015. (6) Operating income (loss) for the Power segment for 2015 includes an impairment charge of $133.1 million . (7) Eliminations for intersegment revenues and cost of sales are presented within the Corporate segment.
Reconciliation of segment operating income to income (loss)	A reconciliation of segment operating income (loss) to loss before income taxes follows: Years Ended December 31, 2015 2014 2013 (In thousands) Operating income (loss) $ (132,341 ) $ (42,975 ) $ 25,362 Interest expense (104,215 ) (84,234 ) (39,937 ) Loss on extinguishment of debt (5,385 ) (49,154 ) (64 ) Interest income 7,993 6,400 1,366 Gain (loss) on foreign exchange 3,674 (4,016 ) — Other income 1,740 1,031 364 Loss before income taxes $ (228,534 ) $ (172,948 ) $ (12,909 )
Schedule of revenue by major customers by segment	The Company derives its revenues from a few key customers. The customers from which more than 10% of total revenue has been derived and the percentage of total revenue from those customers is summarized as follows: December 31, 2015 (1) December 31, 2014 (1) December 31, 2013 (In thousands) Customer A – Coal - U.S. and WMLP $ 203,942 $ — $ — Customer B – Coal - Canada 180,660 144,863 — Customer C – Coal - U.S. 153,585 128,104 117,545 Customer D – Coal - U.S. and WMLP 103,752 101,778 112,061 Customer E – Coal - U.S. 97,449 100,234 89,266 Customer F – Power 84,423 85,254 86,390 Customer G – Coal - U.S. 67,475 79,505 85,929 Percentage of total revenue 63 % 57 % 73 % ____________________ (1) The revenue from Customers D, E, F, and G did not exceed 10% in 2015 and 2014.

QUARTERLY FINANCIAL DATA (UNA48

QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Schedule of quarterly financial data (unaudited)	Summarized quarterly financial data is as follows: Three Months Ended March 31 June 30 September 30 December 31 (1) (In thousands; except per share data) 2015: Revenues $ 371,483 $ 348,959 $ 349,796 $ 340,810 Operating income (loss) 8,455 (6,866 ) (15,307 ) (118,623 ) Net loss applicable to common shareholders (11,732 ) (36,605 ) (46,562 ) (108,418 ) Basic loss per common share $ (0.67 ) $ (2.04 ) $ (2.59 ) $ (6.00 ) 2014: Revenues $ 180,202 $ 287,956 $ 337,830 $ 310,004 Operating income (loss) 8,053 (29,640 ) (29,432 ) 8,044 Net loss applicable to common shareholders (19,291 ) (63,363 ) (49,329 ) (41,135 ) Basic loss per common share $ (1.30 ) $ (4.19 ) $ (2.95 ) $ (2.41 )

SUMMARY OF SIGNIFICANT ACCOUN49

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Acquisition and additional information) (Details) - mines	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Ownership percentage in joint venture (percent)	50.00%
Westmoreland Resource Partners LP [Member]
Business Acquisition [Line Items]
Ownership percentage in partnership (percent)	93.80%	79.00%
OHIO | Westmoreland Resource Partners LP [Member]
Business Acquisition [Line Items]
Number of mines	5
WYOMING | Westmoreland Resource Partners LP [Member]
Business Acquisition [Line Items]
Number of mines	1
CANADA
Business Acquisition [Line Items]
Number of mines	6
Prairie Mines and Royalty ULC [Member] | Minimum [Member]
Business Acquisition [Line Items]
Recognition period for finance income	3 years
Prairie Mines and Royalty ULC [Member] | Maximum [Member]
Business Acquisition [Line Items]
Recognition period for finance income	27 years

SUMMARY OF SIGNIFICANT ACCOUN50

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Property, Plant and Equipment) (Details)	12 Months Ended
	Dec. 31, 2015
Building and Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of property, plant and equipment	5 years
Building and Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of property, plant and equipment	40 years
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of property, plant and equipment	1 year
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of property, plant and equipment	36 years

SUMMARY OF SIGNIFICANT ACCOUN51

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Antidilutive Securities Excluded from Computation of Earnings Per Share) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from diluted shares calculation	482	1,163	1,898
Convertible notes and securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from diluted shares calculation	0	626	1,093
Restricted stock units, stock options, and SARs [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from diluted shares calculation	482	537	805

SUMMARY OF SIGNIFICANT ACCOUN52

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Deferred Taxes) (Details) - New Accounting Pronouncement, Early Adoption, Effect [Member] - USD ($) $ in Millions	Dec. 31, 2014	Dec. 31, 2013
Investments, Owned, Federal Income Tax Note [Line Items]
Non-current liability, deferred income taxes	$ 13.1	$ 5.4
Current asst, deferred income taxes	$ 13.1	$ 5.4

ACQUISITIONS - Summary of purch

ACQUISITIONS - Summary of purchase consideration and allocation of purchase consideration (Details)	Aug. 01, 2015USD ($)	Jan. 01, 2015USD ($)	Dec. 31, 2014USD ($)shares	Jun. 25, 2014USD ($)	Apr. 28, 2014USD ($)mines	Apr. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)shares
Buckingham Coal Company, LLC [Member]
Business Acquisition [Line Items]
Cash purchase price		$ 32,500,000
Allocation of purchase consideration:
Land and mineral rights		12,100,000
Plant and equipment		26,800,000
Total Liabilities		$ (6,400,000)
Westmoreland Resource Partners LP [Member]
Business Acquisition [Line Items]
Units of partnership interest acquired (shares) | shares			4,512,500						4,512,500
Ownership percentage in partnership (percent)								93.80%	79.00%
Quarterly distributions (USD per unit)	$ 0.22					$ 0.20
Acquisition-related costs								$ 300,000	$ 4,500,000
Kemmerer Drop [Member]
Business Acquisition [Line Items]
Gain (loss) recognized on the Drop	0
Allocation of purchase consideration:
Net fair value	$ 102,600,000
Canadian Subsidiaries [Member]
Business Acquisition [Line Items]
Acquisition-related costs									33,600,000
Interest acquired (percent)					50.00%
Number of mines | mines					6
Purchase consideration:
Cash paid - Initial payment					$ 282,800,000
Cash paid - Working capital adjustment				$ 39,800,000
Allocation of purchase consideration:
Total Liabilities					(421,300,000)
Westmoreland Resources GP, LLC [Member]
Business Acquisition [Line Items]
Cash purchase price			$ 33,500,000
Goodwill			0						$ 0
Useful life of intangible assets									15 years
Partnership interest, conversion ratio	1
Purchase consideration:
Cash paid - Initial payment			30,000,000
Contingent consideration			3,500,000						$ 3,500,000
Fair value of outstanding WMLP units			10,800,000						10,800,000
Total purchase consideration			44,300,000
Allocation of purchase consideration:
Receivables			22,500,000						22,500,000
Inventories - materials and supplies			7,400,000						7,400,000
Inventories - coal			6,600,000						6,600,000
Other current assets			1,300,000						1,300,000
Total current assets			37,800,000						37,800,000
Land and mineral rights			40,200,000						40,200,000
Plant and equipment			134,000,000						134,000,000
Advanced coal royalties			9,200,000						9,200,000
Restricted investments and bond collateral			10,600,000						10,600,000
Intangible assets			31,000,000						31,000,000
Other assets			200,000						200,000
Total assets			263,000,000						263,000,000
Trade payables and other accrued liabilities			(19,100,000)						(19,100,000)
Asset retirement obligations			(7,800,000)						(7,800,000)
Other current liabilities			(4,000,000)						(4,000,000)
Total current liabilities			(30,900,000)						(30,900,000)
Long-term debt, less current installments			(160,100,000)						(160,100,000)
Asset retirement obligations, less current portion			(23,900,000)						(23,900,000)
Warrants			(2,000,000)						(2,000,000)
Other liabilities			(1,800,000)						(1,800,000)
Total Liabilities			(218,700,000)						(218,700,000)
Net fair value			44,300,000						44,300,000
Non-controlling Interest			(10,800,000)						(10,800,000)
Invested Equity			33,500,000						33,500,000
Canadian Acquisition [Member]
Business Acquisition [Line Items]
Cash purchase price			322,600,000
Repayment of assumed liability					18,100,000
Net cash received in the acquisition					8,100,000
Intangible asset transferred							$ 37,000,000
Proceeds from transfer of intangible asset							37,000,000
Gain (loss) on transfer of intangible asset							$ 0
Indemnification asset					$ 27,900,000
Purchase consideration:
Cash paid - Initial payment			282,800,000
Cash paid - Working capital adjustment			39,800,000
Allocation of purchase consideration:
Cash and cash equivalents			26,200,000						26,200,000
Receivables			78,100,000						78,100,000
Inventories - materials and supplies			52,000,000						52,000,000
Inventories - coal			79,800,000						79,800,000
Loan and lease receivables			11,200,000						11,200,000
Deferred tax assets			8,200,000						8,200,000
Other current assets			3,400,000						3,400,000
Total current assets			258,900,000						258,900,000
Land and mineral rights			202,600,000						202,600,000
Plant and equipment			114,800,000						114,800,000
Loan and lease receivables			79,100,000						79,100,000
Contractual third-party reclamation receivables, less current portion			6,800,000						6,800,000
Investment in joint venture			36,000,000						36,000,000
Intangible assets			37,000,000						37,000,000
Other assets			8,700,000						8,700,000
Total assets			743,900,000						743,900,000
Current installments of long-term debt			(36,300,000)						(36,300,000)
Trade payables and other accrued liabilities			(136,100,000)						(136,100,000)
Asset retirement obligations			(7,800,000)						(7,800,000)
Total current liabilities			(180,200,000)						(180,200,000)
Long-term debt, less current installments			(86,300,000)						(86,300,000)
Asset retirement obligations, less current portion			(122,900,000)						(122,900,000)
Deferred tax liabilities			(31,900,000)						(31,900,000)
Total Liabilities			(421,300,000)						(421,300,000)
Net fair value			$ 322,600,000						322,600,000
Cost of Sales [Member] | Canadian Subsidiaries [Member]
Business Acquisition [Line Items]
Acquisition-related costs									14,200,000
Selling, General and Administrative Expenses [Member] | Canadian Subsidiaries [Member]
Business Acquisition [Line Items]
Acquisition-related costs									8,300,000
Foreign Currency Gain (Loss) [Member] | Canadian Subsidiaries [Member]
Business Acquisition [Line Items]
Acquisition-related costs									6,200,000
Interest Expense [Member] | Canadian Subsidiaries [Member]
Business Acquisition [Line Items]
Acquisition-related costs									$ 4,900,000
Westmoreland Kemmerer, LLC [Member]
Business Acquisition [Line Items]
Ownership interest in LLC (percent)	100.00%
Aggregate consideration received from contribution of LLC	$ 230,000,000
Cash consideration received	115,000,000
WMLP Series A Convertible Units [Member] | Westmoreland Kemmerer, LLC [Member]
Business Acquisition [Line Items]
Partnership units received as consideration	$ 115,000,000

ACQUISITIONS - Summary of Pro F

ACQUISITIONS - Summary of Pro Forma Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Total Revenues
As reported	$ 340,810	$ 349,796	$ 348,959	$ 371,483	$ 310,004	$ 337,830	$ 287,956	$ 180,202	$ 1,411,048	$ 1,115,992	$ 674,686
Pro forma										1,644,474	1,673,538
Operating Income
As reported	(118,623)	(15,307)	(6,866)	8,455	8,044	(29,432)	(29,640)	8,053	(132,341)	(42,975)	25,362
Pro forma										(38,827)	36,097
Net income (loss) applicable to common shareholders
As reported	$ (108,418)	$ (46,562)	$ (36,605)	$ (11,732)	$ (41,135)	$ (49,329)	$ (63,363)	$ (19,291)	$ (203,317)	(173,118)	(6,057)
Pro forma										$ (135,647)	$ (62,595)
Net income (loss) per share applicable to common shareholders
As reported (in USD per share)									$ (11.36)	$ (10.86)	$ (0.42)
Pro forma (in USD per share)										$ (8.51)	$ (4.32)

LOSS ON IMPAIRMENT (Details)

LOSS ON IMPAIRMENT (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Loss on impairment	$ 136,210	$ 0	$ 0
Power [Member]
Property, Plant and Equipment [Line Items]
Loss on impairment	133,100
Coal Canada Segment [Member]
Property, Plant and Equipment [Line Items]
Loss on impairment	$ 3,100

INVENTORIES (Detail)

INVENTORIES (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Coal stockpiles	$ 38,636	$ 41,795
Coal fuel inventories	7,194	6,531
Materials and supplies	78,784	88,584
Reserve for obsolete inventory	(2,756)	(3,055)
Total	$ 121,858	$ 133,855

RESTRICTED INVESTMENTS AND BO57

RESTRICTED INVESTMENTS AND BOND COLLATERAL - Components of Restricted Investments and Bond Collateral (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Restricted Investments and Bond Collateral [Line Items]
Total restricted investments and bond collateral	$ 140,804	$ 164,389
Coal Canada Segment [Member] | Prairie Mines and Royalty ULC [Member]
Restricted Investments and Bond Collateral [Line Items]
Total restricted investments and bond collateral	18,228	18,199
Coal Canada Segment [Member] | Coal Valley Resources Inc. [Member]
Restricted Investments and Bond Collateral [Line Items]
Total restricted investments and bond collateral	33,872	31,866
Coal Westmoreland Resource Partners LP [Member] | OHIO
Restricted Investments and Bond Collateral [Line Items]
Total restricted investments and bond collateral	6,895	10,634
Coal Westmoreland Resource Partners LP [Member] | Kemmerer Mine [Member]
Restricted Investments and Bond Collateral [Line Items]
Total restricted investments and bond collateral	27,631	25,282
Reclamation Bond Collateral [Member] | Coal U.S. Segment [Member] | Absaloka Mine [Member]
Restricted Investments and Bond Collateral [Line Items]
Total restricted investments and bond collateral	11,810	11,781
Reclamation Bond Collateral [Member] | Coal U.S. Segment [Member] | Rosebud Mine [Member]
Restricted Investments and Bond Collateral [Line Items]
Total restricted investments and bond collateral	3,145	3,145
Reclamation Bond Collateral [Member] | Coal U.S. Segment [Member] | Beulah Mine [Member]
Restricted Investments and Bond Collateral [Line Items]
Total restricted investments and bond collateral	1,270	1,270
Reclamation Bond Collateral [Member] | Buckingham Acquisition Escrow [Member] | Coal U.S. Segment [Member]
Restricted Investments and Bond Collateral [Line Items]
Total restricted investments and bond collateral	0	34,000
Power Contract Collateral [Member] | Power [Member]
Restricted Investments and Bond Collateral [Line Items]
Total restricted investments and bond collateral	22,200	12,600
Postretirement Medical Benefit Bonds [Member] | Corporate [Member]
Restricted Investments and Bond Collateral [Line Items]
Total restricted investments and bond collateral	8,897	8,780
Workers' Compensation Bonds [Member] | Corporate [Member]
Restricted Investments and Bond Collateral [Line Items]
Total restricted investments and bond collateral	$ 6,856	$ 6,832

RESTRICTED INVESTMENTS AND BO58

RESTRICTED INVESTMENTS AND BOND COLLATERAL - Carrying Value and Estimated Fair Value of Restricted Investments and Bond Collateral (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Investment [Line Items]
Restricted investments and bond collateral	$ 140,807	$ 164,389
Carrying Value [Member]
Investment [Line Items]
Cash and cash equivalents	102,536
Time deposits	2,455
Available-for-sale	35,813
Restricted investments and bond collateral	140,804
Fair Value [Member]
Investment [Line Items]
Restricted investments and bond collateral	140,804
Quoted prices in active markets for identical assets - Level 1 [Member] | Fair Value [Member]
Investment [Line Items]
Cash and cash equivalents	102,536
Time deposits	2,455
Available-for-sale	$ 35,813

RESTRICTED INVESTMENTS AND BO59

RESTRICTED INVESTMENTS AND BOND COLLATERAL - Cost Basis, Gross Unrealized Holding Gains and Fair Value of Available-for-Sale Securities (Detail) - Restricted Investments and Bond Collateral [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Cost basis	$ 36,715	$ 33,879
Gross unrealized holding gains	167	761
Gross unrealized holding losses	(1,069)	(583)
Fair value	$ 35,813	$ 34,057

RESTRICTED INVESTMENTS AND BO60

RESTRICTED INVESTMENTS AND BOND COLLATERAL - Available for Sale Maturity Schedule (Details) - Restricted Investments and Bond Collateral [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Within one year, Amortized cost	$ 1,127
Due in five years or less, Amortized cost	15,522
Due after five years to ten years, Amortized cost	5,142
Due in more than ten years, Amortized cost	14,924
Cost basis	36,715	$ 33,879
Within one year, Fair Value	1,057
Due in five years or less, Fair Value	14,896
Due after five years to ten years, Fair Value	4,939
Due in more than ten years, Fair Value	$ 14,921
Fair value		$ 35,813

RESTRICTED INVESTMENTS AND BO61

RESTRICTED INVESTMENTS AND BOND COLLATERAL - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure Restricted Investments and Bond Collateral [Abstract]
Gain on sale of available-for-sale securities held as restricted investments and bond collateral (less than $0.1 million for 2013)	$ 0.1	$ 0.3	$ 0.1

INTANGIBLE ASSETS AND LIABILI62

INTANGIBLE ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 0		$ 1,700
Amortization of intangible liabilities	1,000	$ 1,000	$ 1,000
Amount of Amortization to Recognize in Revenues
2,016	1,068
2,017	1,068
2,018	1,068
2,019	267
2,020	0
Amount of Amortization to Recognize in Cost of Sales
2,016	2,130
2,017	2,130
2,018	2,130
2,019	2,105
2,020	$ 2,096

RESTRUCTURING CHARGES (Details)

RESTRUCTURING CHARGES (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring Reserve [Roll Forward]
Beginning balance	$ 9,200,000	$ 5,100,000
Restructuring charges	656,000	14,989,000	$ 5,078,000
Cash Payments	(9,000,000)	(10,900,000)
Ending balance	900,000	9,200,000	$ 5,100,000
ROVA Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Remaining Period of Contract			5 years
Restructuring costs incurred to date	5,500,000
Restructuring Reserve [Roll Forward]
Beginning balance	400	5,100
Restructuring charges	0	500
Cash Payments	(400)	(5,200)
Ending balance	0	400	$ 5,100
Acquisition Restructuring Plans [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs expected	15,200,000
Restructuring Reserve [Roll Forward]
Beginning balance	8,800	0
Restructuring charges	700	14,500
Cash Payments	(8,600)	(5,700)
Ending balance	$ 900	$ 8,800	$ 0

LINES OF CREDIT AND LONG-TERM64

LINES OF CREDIT AND LONG-TERM DEBT - Outstanding Lines of Credit and Long-Term Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Total debt outstanding	$ 1,045,714	$ 984,787
Less current portion	(40,822)	(52,712)
Total debt outstanding, less current portion	1,004,892	932,075
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Total debt outstanding	71,168	109,351
Other [Member]
Debt Instrument [Line Items]
Total debt outstanding	7,251	4,062
Debt Discount [Member]
Debt Instrument [Line Items]
Total debt outstanding	(11,095)	(13,202)
Senior Secured Notes Due 2021 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total debt outstanding	350,000	350,000
Term Loan Facility Due 2020 [Member] | Term Notes [Member]
Debt Instrument [Line Items]
Total debt outstanding	327,172	350,000
WMLP Term Debt Due 2018 [Member] | Term Notes [Member]
Debt Instrument [Line Items]
Total debt outstanding	299,248	175,000
Revolving Credit Facility [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Total debt outstanding	$ 1,970	$ 9,576

LINES OF CREDIT AND LONG-TERM65

LINES OF CREDIT AND LONG-TERM DEBT - Aggregate Contractual Debt Maturities of All Long-Term Debt and Lines of Credit (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Maturities of Long-term Debt [Abstract]
2,016	$ 40,822
2,017	31,846
2,018	11,094
2,019	307,733
2,020	315,314
Thereafter	350,000
Total	1,056,809
Less: debt discount	(11,095)
Total debt outstanding	$ 1,045,714	$ 984,787

LINES OF CREDIT AND LONG-TERM66

LINES OF CREDIT AND LONG-TERM DEBT - Additional Information (Detail) - USD ($)	Aug. 01, 2015	Jan. 22, 2015	Dec. 16, 2014	Dec. 31, 2015	Dec. 31, 2014	Jul. 31, 2015	Jul. 30, 2015	Jun. 02, 2015	Mar. 31, 2014
Senior Notes:
Aggregate principal amount				$ 1,056,809,000
Capital leases entered into during the period				15,200,000
Revolving Credit Facility [Member]
Senior Notes:
Line of credit facility maximum borrowing capacity			$ 50,000,000						$ 60,000,000
Line of credit facility, remaining borrowing capacity				28,200,000
Letters of credit outstanding amount				19,800,000
Line of credit outstanding				$ 2,000,000
Debt issuance costs capitalized					$ 700,000
Unused line fee (percent)			0.50%
Capital Lease Obligations [Member]
Senior Notes:
Weighted average interest rate (percent)				4.51%	4.66%
Senior Secured Notes Due 2021 [Member] | Senior Notes [Member]
Senior Notes:
Additional financing obtained per the Amended Financing Agreement			$ 350,000,000
Discount rate used for issuance of notes (percent)			1.292%
Stated interest rate			8.75%
Capitalized debt issuance costs				$ 10,200,000
Redemption price as percent of principal (percent)				100.00%
Percentage of aggregate principal that may be redeemed (percent)				35.00%
Price, as a percentage of face value (percent)				108.75%
Term Loan Facility Due 2020 [Member] | Term Notes [Member]
Senior Notes:
Additional financing obtained per the Amended Financing Agreement		$ 75,000,000	$ 350,000,000
Discount rate used for issuance of notes (percent)			2.50%
Capitalized debt issuance costs					$ 8,400,000
Interest rate at year period end				7.50%
Aggregate principal amount		425,000,000
Proceeds from term loan		$ 71,000,000
Discount rate used for issuance of add-on term loan (percent)		2.50%
Broker fee (percent)		1.50%
Consent fee (percent)		1.17%
Additional debt issuance cost		$ 100,000
USD Denominated Sub-facility [Member] | Revolving Credit Facility [Member]
Senior Notes:
Line of credit facility maximum borrowing capacity			$ 30,000,000
CAD-Denominated Sub-facility [Member] | Revolving Credit Facility [Member]
Senior Notes:
Line of credit facility maximum borrowing capacity			$ 20,000,000
WMLP Term Debt Due 2018 [Member]
Senior Notes:
Restrictive covenant, maximum aggregate distribution						$ 15,000,000	$ 7,500,000
Restrictive covenant, minimum liquidity						$ 7,500,000	$ 5,000,000
WMLP Term Debt Due 2018 [Member] | Term Notes [Member]
Senior Notes:
Additional financing obtained per the Amended Financing Agreement					175,000,000
Interest rate at year period end				9.25%
Option for additional term loan					$ 120,000,000
Outstanding balance				$ 299,200,000
Fixed portion of the effective interest rate (percent)				8.50%
Paid-in-kind Interest				$ 6,900,000
Credit Facility Seasonal Increase to Borrowing Capacity [Member] | Revolving Credit Facility [Member]
Senior Notes:
Line of credit facility maximum borrowing capacity								$ 75,000,000
Base Rate [Member] | Revolving Credit Facility [Member]
Senior Notes:
Spread on basis, percentage			0.75%
LIBOR [Member] | Revolving Credit Facility [Member]
Senior Notes:
Spread on basis, percentage			2.75%
LIBOR [Member] | Term Loan Facility Due 2020 [Member] | Term Notes [Member]
Senior Notes:
Spread on basis, percentage			6.50%
LIBOR [Member] | WMLP Term Debt Due 2018 [Member] | Term Notes [Member]
Senior Notes:
Spread on basis, percentage				0.75%
Westmoreland Kemmerer, LLC [Member] | Term Loan Facility Due 2020 [Member] | Term Notes [Member]
Senior Notes:
Repayments of debt	$ 94,100,000
Minimum [Member] | WMLP Term Debt Due 2018 [Member] | Term Notes [Member]
Senior Notes:
Paid-in-kind interest (percent)				1.00%
Maximum [Member] | WMLP Term Debt Due 2018 [Member] | Term Notes [Member]
Senior Notes:
Paid-in-kind interest (percent)				3.00%

POSTRETIREMENT MEDICAL BENEFI67

POSTRETIREMENT MEDICAL BENEFITS - Postretirement Medicial Benefit Obligations Balance Sheet Disclosures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Amounts recognized in the balance sheet consist of:
Noncurrent liabilities	$ (44,808)	$ (49,779)
Accumulated other comprehensive loss	65,644	75,781	$ 32,547	$ 122,246
Amounts recognized in accumulated other comprehensive loss consist of:
Accumulated other comprehensive loss	65,644	75,781	32,547	$ 122,246
Postretirement Medical Benefits [Member]
Change in benefit obligation:
Net benefit obligation at beginning of year	306,418	284,329
Service cost	4,217	3,289	4,436
Interest cost	11,629	12,814	12,139
Plan participant contributions	185	149
Actuarial loss (gain)	(7,322)	19,441
Gross benefits paid	(17,013)	(14,860)
Federal subsidy on benefits paid	1,259	1,256
Net benefit obligation at end of year	299,373	306,418	$ 284,329
Change in plan assets:
Employer contributions	16,828	14,711
Plan participant contributions	185	149
Gross benefits paid	(17,013)	(14,860)
Fair value of plan assets at end of year	0	0
Unfunded status at end of year	(299,373)	(306,418)
Amounts recognized in the balance sheet consist of:
Current liabilities	(13,855)	(13,263)
Noncurrent liabilities	(285,518)	(293,156)
Accumulated other comprehensive loss	31,085	39,716
Net amount recognized at end of year	(268,288)	(266,703)
Amounts recognized in accumulated other comprehensive loss consist of:
Net actuarial loss	35,534	44,800
Prior service cost	(4,449)	(5,084)
Accumulated other comprehensive loss	$ 31,085	$ 39,716

POSTRETIREMENT MEDICAL BENEFI68

POSTRETIREMENT MEDICAL BENEFITS - Postretirement Medical Benefit Obligations Income Statement Disclosures (Details) - Postretirement Medical Benefits [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Amounts that will be amortized from accumulated other comprehensive loss into net periodic pension cost:
Net actuarial loss	$ 1,400
Prior service credit	(600)
Components of net periodic benefit cost:
Service cost	4,217	$ 3,289	$ 4,436
Interest cost	11,629	12,814	12,139
Amortization of:
Prior service cost (credit)	(636)	(635)	(636)
Actuarial loss	1,944	653	4,641
Total net periodic benefit cost	17,154	16,121	20,580
Net periodic postretirement medical benefit costs relating to current and former mining operations:
Total net periodic benefit cost	17,154	16,121	20,580
Former Mining Operations [Member]
Amortization of:
Total net periodic benefit cost	8,137	9,614	12,475
Net periodic postretirement medical benefit costs relating to current and former mining operations:
Total net periodic benefit cost	8,137	9,614	12,475
Current Operations [Member]
Amortization of:
Total net periodic benefit cost	9,017	6,507	8,105
Net periodic postretirement medical benefit costs relating to current and former mining operations:
Total net periodic benefit cost	$ 9,017	$ 6,507	$ 8,105

POSTRETIREMENT MEDICAL BENEFI69

POSTRETIREMENT MEDICAL BENEFITS Assumptions Used (Details) - Postretirement Medical Benefits [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assumed health care trend rates:
Health care cost trend rate assumed for next year	7.00%	6.50%
Rate to which the cost trend is assumed to decline (ultimate trend rate)	4.75%	5.00%
Year that the trend rate reaches the ultimate trend rate	2,025	2,021
Effect of a 1% change in the health care cost trend rate:
Effect of 1% increase on service and interest cost components	$ 3,235
Effect of 1% decrease on service and interest cost components	(2,444)
Effect of 1% increase on postretirement medical benefit obligation	41,360
Effect of 1% decrease on postretirement medical benefit obligation	$ (33,667)
Minimum [Member]
Weighted-average discount rates used in calculations:
Rate used to determine benefit obligations as of the end of the year shown	4.10%	3.75%
Rate used to determine net periodic benefit cost for the year shown	3.75%	4.50%	3.60%
Maximum [Member]
Weighted-average discount rates used in calculations:
Rate used to determine benefit obligations as of the end of the year shown	4.65%	4.25%
Rate used to determine net periodic benefit cost for the year shown	4.25%	5.05%	4.15%

POSTRETIREMENT MEDICAL BENEFI70

POSTRETIREMENT MEDICAL BENEFITS Expected Future Cash Flows (Details) - Postretirement Medical Benefits [Member] $ in Thousands	Dec. 31, 2015USD ($)
Expected future payments, postretirement medical benefits:
2016 - Postretirement Medical Benefits	$ 13,855
2017 - Postretirement Medical Benefits	14,250
2018 - Postretirement Medical Benefits	14,744
2019 - Postretirement Medical Benefits	15,205
2020 - Postretirement Medical Benefits	15,627
Years 2021 - 2025 - Postretirement Medical Benefits	82,997
Expected future receipts, Medicare D Subsidy:
2013 - Medicare D Subsidy	(1,388)
2014 - Medicare D Subsidy	(1,457)
2015 - Medicare D Subsidy	(1,516)
2016 - Medicare D Subsidy	(1,573)
2017 - Medicare D Subsidy	(1,623)
Years 2018 - 2022 - Medicare D Subsidy	(8,830)
Expected future payments, net
2013 - Net Postretirement Medical Benefits	12,467
2014 - Net Postretirement Medical Benefits	12,793
2015 - Net Postretirement Medical Benefits	13,228
2016 - Net Postretirement Medical Benefits	13,632
2017 - Net Postretirement Medical Benefits	14,004
Years 2018 - 2022 - Net Postretirement Medical Benefits	$ 74,167

POSTRETIREMENT MEDICAL BENEFI71

POSTRETIREMENT MEDICAL BENEFITS Pneumoconiosis (Black Lung) Benefit Obligation (Details) - Pneumoconiosis (Black Lung) Benefits [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Pneumoconiosis Benefit Obligation [Abstract]
Net benefit obligation at end of year	$ 17,790	$ 14,007
Plan assets at fair value, primarily government-backed securities	570	2,755
Unfunded status at end of year	$ 17,220	$ 11,252
Rate used to determine benefit obligations as of the end of the year shown	3.95%	3.40%
Quoted prices in active markets for identical assets - Level 1 [Member]
Pneumoconiosis Benefit Obligation [Abstract]
Trust assets	$ 2,755
US Treasury Securities [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Pneumoconiosis Benefit Obligation [Abstract]
Trust assets	2,615
Cash and cash equivalents [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Pneumoconiosis Benefit Obligation [Abstract]
Trust assets	140
Terminated Employees [Member]
Pneumoconiosis Benefit Obligation [Abstract]
Net benefit obligation at end of year	2,472	$ 953
Existing Claimants [Member]
Pneumoconiosis Benefit Obligation [Abstract]
Net benefit obligation at end of year	15,318	$ 13,054
Fair Value [Member]
Pneumoconiosis Benefit Obligation [Abstract]
Trust assets	570
Fair Value [Member] | US Treasury Securities [Member]
Pneumoconiosis Benefit Obligation [Abstract]
Trust assets	256
Fair Value [Member] | Cash and cash equivalents [Member]
Pneumoconiosis Benefit Obligation [Abstract]
Trust assets	$ 314

POSTRETIREMENT MEDICAL BENEFI72

POSTRETIREMENT MEDICAL BENEFITS - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Transition Obligation Amortization Period	20 years
Workers' Compensation Disclosure [Abstract]
Workers' compensation, beginning of year (including current portion)	$ 6,986	$ 7,461
Accretion	127	200
Claims paid	(448)	(405)
Actuarial changes	(1,007)	(270)
Workers' compensation, end of year	5,658	6,986	$ 7,461
Less current portion	(590)	(671)
Workers’ compensation, less current portion	$ 5,068	$ 6,315
Workers' compensation discount, percent	2.20%	2.00%
Combined Benefit Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Multiemployer Plan, Period Contributions	$ 1,800	$ 2,000	$ 2,200

PENSION AND OTHER SAVING PLAN -

PENSION AND OTHER SAVING PLAN - Balance Sheet Disclosures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Amounts recognized in the accompanying balance sheet consist of:
Accumulated other comprehensive loss	$ 65,644	$ 75,781	$ 32,547	$ 122,246
Amounts recognized in accumulated other comprehensive loss consist of:
Accumulated other comprehensive loss (gain)	65,644	75,781	32,547	$ 122,246
Pension [Member]
Change in benefit obligation:
Net benefit obligation at beginning of year	206,966	155,075
Liability acquired	0	36,087
Service cost	1,760	2,425	2,346
Interest cost	7,282	7,963	6,209
Actuarial loss (gain)	(11,514)	32,505
Benefits and expenses paid	(17,974)	(15,119)
Settlements and curtailments	(1,559)	(10,862)
Plan amendments	0	207
Foreign currency exchange rate changes	(3,532)	(1,315)
Net benefit obligation at end of year	181,429	206,966	155,075
Change in plan assets:
Fair value of plan assets at beginning of year	160,947	134,149
Assets acquired	0	36,616
Actual return on plan assets	(2,379)	14,392
Employer contributions	3,727	4,812
Settlements	124	(12,795)
Foreign currency exchange rate changes	(3,308)	(1,108)
Fair value of plan assets at end of year	141,137	160,947	134,149
Unfunded status at end of year	(40,292)	(46,019)
Amounts recognized in the accompanying balance sheet consist of:
Noncurrent asset, included in Other assets	1,082	0
Current liability	0	0
Noncurrent liability	(41,374)	(46,019)
Accumulated other comprehensive loss	33,313	34,249
Net amount recognized at end of year	(6,979)	(11,770)
Amounts recognized in accumulated other comprehensive loss consist of:
Net actuarial loss	33,236	34,164
Prior service cost	77	85
Accumulated other comprehensive loss (gain)	33,313	34,249
SERP [Member]
Change in benefit obligation:
Net benefit obligation at beginning of year	4,129	3,640
Liability acquired	0	0
Service cost	0	0	0
Interest cost	153	168	152
Actuarial loss (gain)	(108)	704
Benefits and expenses paid	(372)	(383)
Settlements and curtailments	0	0
Plan amendments	0	0
Foreign currency exchange rate changes	0	0
Net benefit obligation at end of year	3,802	4,129	3,640
Change in plan assets:
Fair value of plan assets at beginning of year	0	0
Assets acquired	0	0
Actual return on plan assets	0	0
Employer contributions	372	383
Settlements	0	0
Foreign currency exchange rate changes	0	0
Fair value of plan assets at end of year	0	0	$ 0
Unfunded status at end of year	(3,802)	(4,129)
Amounts recognized in the accompanying balance sheet consist of:
Noncurrent asset, included in Other assets	0	0
Current liability	(368)	(368)
Noncurrent liability	(3,434)	(3,760)
Accumulated other comprehensive loss	1,589	1,815
Net amount recognized at end of year	(2,213)	(2,313)
Amounts recognized in accumulated other comprehensive loss consist of:
Net actuarial loss	1,589	1,815
Prior service cost	0	0
Accumulated other comprehensive loss (gain)	$ 1,589	$ 1,815

PENSION AND OTHER SAVINGS PLANS

PENSION AND OTHER SAVINGS PLANS - Income Statement Disclosures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 100
Components of net periodic benefit cost:
Service cost	0	$ 0	$ 0
Interest cost	153	$ 168	152
Expected return on plan assets	0		0
Settlements and curtailments	0	$ 0	0
Prior service cost (credit)	0	0	0
Actuarial loss	118	97	112
Total net periodic benefit cost	271	265	264
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	5,600
Components of net periodic benefit cost:
Service cost	1,760	2,425	2,346
Interest cost	7,282	7,963	6,209
Expected return on plan assets	(10,033)	(10,796)	(8,770)
Settlements and curtailments	(1,683)	4,585	0
Prior service cost (credit)	8	0	0
Actuarial loss	2,840	1,217	3,377
Total net periodic benefit cost	$ 174	$ 5,394	$ 3,162

PENSION AND OTHER SAVING PLAN75

PENSION AND OTHER SAVING PLANS - Assumptions Used (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets, percentage		7.40%	7.40%
Pension [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate used to determine benefit obligations as of the end of the year shown	3.90%	3.60%
Rate used to determine net periodic benefit cost for the year shown	3.60%	4.25%	3.35%
Expected return on plan assets, percentage	3.66%
Pension [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate used to determine benefit obligations as of the end of the year shown	4.25%	3.90%
Rate used to determine net periodic benefit cost for the year shown	3.90%	4.70%	3.75%
Expected return on plan assets, percentage	7.10%
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Rate used to determine benefit obligations as of the end of the year shown	4.25%	3.90%
Rate used to determine net periodic benefit cost for the year shown	3.90%	4.65%	3.75%

PENSION AND OTHER SAVING PLAN76

PENSION AND OTHER SAVING PLANS - Information on Plan Assets (Details) - Pension [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Unrealized (loss) gain		$ (2,379)	$ 14,392
Settlements		124	(12,795)
Quoted prices in active markets for identical assets - Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		30,639
Plan assets, ending balance		19,662	30,639
Significant other observable inputs - Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		130,084
Plan assets, ending balance		121,339	130,084
Significant unobservable inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		224
Plan assets, ending balance		136	224
Large-cap pooled separate accounts [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[1]	0
Plan assets, ending balance		0	0	[1]
Large-cap pooled separate accounts [Member] | Significant other observable inputs - Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[1]	47,092
Plan assets, ending balance		43,417	47,092	[1]
Large-cap pooled separate accounts [Member] | Significant unobservable inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[1]	0
Plan assets, ending balance		0	0	[1]
International blend [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[2]	0
Plan assets, ending balance		0	0	[2]
International blend [Member] | Significant other observable inputs - Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[2]	7,290
Plan assets, ending balance		7,779	7,290	[2]
International blend [Member] | Significant unobservable inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[2]	0
Plan assets, ending balance		$ 0	0	[2]
Fixed income domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Corporate bond maturity period		15 years
Fixed income domestic [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[3]	$ 0
Plan assets, ending balance		0	0	[3]
Fixed income domestic [Member] | Significant other observable inputs - Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[3]	23,057
Plan assets, ending balance		22,115	23,057	[3]
Fixed income domestic [Member] | Significant unobservable inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[3]	0
Plan assets, ending balance		0	0	[3]
Fixed income long term [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[4]	0
Plan assets, ending balance		0	0	[4]
Fixed income long term [Member] | Significant other observable inputs - Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[4]	47,299
Plan assets, ending balance		43,091	47,299	[4]
Fixed income long term [Member] | Significant unobservable inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[4]	0
Plan assets, ending balance		0	0	[4]
Stable value [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[5]	0
Plan assets, ending balance		0	0	[5]
Stable value [Member] | Significant other observable inputs - Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[5]	5,346
Plan assets, ending balance		4,937	5,346	[5]
Stable value [Member] | Significant unobservable inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[5]	0
Plan assets, ending balance		0	0	[5]
Registered investment companies - growth fund [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		16,490
Plan assets, ending balance		15,447	16,490
Registered investment companies - growth fund [Member] | Significant other observable inputs - Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		0
Plan assets, ending balance		0	0
Registered investment companies - growth fund [Member] | Significant unobservable inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		0
Plan assets, ending balance		0	0
Limited partnerships and limited liability companies [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		0
Plan assets, ending balance		0	0
Limited partnerships and limited liability companies [Member] | Significant other observable inputs - Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		0
Plan assets, ending balance		0	0
Limited partnerships and limited liability companies [Member] | Significant unobservable inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		224
Plan assets, ending balance		136	224
Westmoreland Coal common stock [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		1,539
Plan assets, ending balance		273	1,539
Westmoreland Coal common stock [Member] | Significant other observable inputs - Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		0
Plan assets, ending balance		0	0
Westmoreland Coal common stock [Member] | Significant unobservable inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		0
Plan assets, ending balance		$ 0	0
Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation - minimum		0.00%
Target asset allocation - maximum		10.00%
Cash and cash equivalents [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		$ 12,610
Plan assets, ending balance		3,942	12,610
Cash and cash equivalents [Member] | Significant other observable inputs - Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		0
Plan assets, ending balance		0	0
Cash and cash equivalents [Member] | Significant unobservable inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		0
Plan assets, ending balance		$ 0	0
Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation - minimum		20.00%
Target asset allocation - maximum		60.00%
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation - minimum		40.00%
Target asset allocation - maximum		80.00%
Other Asset Category [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation - minimum		0.00%
Target asset allocation - maximum		10.00%
Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		$ 160,947
Plan assets, ending balance		141,137	160,947
Fair Value [Member] | Large-cap pooled separate accounts [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[1]	47,092
Plan assets, ending balance		43,417	47,092	[1]
Fair Value [Member] | International blend [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[2]	7,290
Plan assets, ending balance		7,779	7,290	[2]
Fair Value [Member] | Fixed income domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[3]	23,057
Plan assets, ending balance		22,115	23,057	[3]
Fair Value [Member] | Fixed income long term [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[4]	47,299
Plan assets, ending balance		43,091	47,299	[4]
Fair Value [Member] | Stable value [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance	[5]	5,346
Plan assets, ending balance		4,937	5,346	[5]
Fair Value [Member] | Registered investment companies - growth fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		16,490
Plan assets, ending balance		15,447	16,490
Fair Value [Member] | Limited partnerships and limited liability companies [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		224
Plan assets, ending balance		136	224
Fair Value [Member] | Westmoreland Coal common stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		1,539
Plan assets, ending balance		273	1,539
Fair Value [Member] | Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets, beginning balance		12,610
Plan assets, ending balance		$ 3,942	$ 12,610
[1]	Large-cap blend funds seek to provide long-term growth of capital. They seek to provide investment results that approximate the performance of the Standard & Poor’s Composite 1500 Index.
[2]	International blends seek to have a diversified portfolio of investments, invading fixed-income and equity-focused investments in international markets.
[3]	Fixed income domestic funds seek to invest in high-quality corporate bonds with over 15 years to maturity.
[4]	Fixed income long term bond funds seek to achieve performance results similar to the Barclays Capital U.S. Aggregate Bond Index. This fund invests primarily in corporate and government bonds.
[5]	The stable value fund seeks to invest in publicly traded and privately placed debt securities and mortgage loans, and to a lesser extent, real estate and other equity investments in order to provide a guaranteed rate of return.The Company’s Level 1 assets include securities held by registered investment companies and its common stock,

PENSION AND OTHER SAVING PLAN77

PENSION AND OTHER SAVING PLANS - Multiemployer Plans (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)$ / Hour	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Jan. 31, 2012
Multiemployer Plans [Line Items]
Multiemployer Plans Funded Status Minimum Percentage				80.00%
WECO [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan Minimum Contribution Per Hour Worked	5.85
Multiemployer Plan Maximum Contribution Per Hour Worked	5.90
Multiemployer Plan, Period Contributions | $	$ 3.6	$ 3.3	$ 3.4
WRI [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan Minimum Contribution Per Hour Worked	4.03
Multiemployer Plan Maximum Contribution Per Hour Worked	4.39
Multiemployer Plan, Period Contributions | $	$ 1.1	1.2	0.9
WSC [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan Minimum Contribution Per Hour Worked	3.70
Multiemployer Plan, Period Contributions | $	$ 0.1	$ 0.1	$ 0.1

PENSION AND OTHER SAVINGS PLA78

PENSION AND OTHER SAVINGS PLANS - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, number of continuous years of employment	5 years
401-K [Member]
Defined Benefit Plan Disclosure [Line Items]
Term For Loan Covenant Criteria	8 months 15 days
Expected contributions	$ 500
Total pension contributions	3,700
2016 - Pension	10,846
2017 - Pension	9,048
2018 - Pension	9,280
2019 - Pension	9,758
2020 - Pension	10,111
Years 2021 - 2025 - Pension	54,006
401-K [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash pension contributions	7,100	$ 6,700	$ 1,200
Stock pension contributions	3,700	1,800	2,400
Defined Contribution Plan, Cost Recognized	$ 10,800	8,500	$ 3,600
Beulah Mine [Member]
Defined Benefit Plan Disclosure [Line Items]
Loss due to settlements		3,700
Loss due to curtailments		$ 900

HERITAGE HEALTH BENEFIT EXPEN79

HERITAGE HEALTH BENEFIT EXPENSES - Components of Costs of Benefits to Former Mining Operation Employees (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Heritage Health Benefit Expenses [Abstract]
Health care benefits	$ 8,179	$ 9,473	$ 12,579
Combined benefit fund payments	1,794	1,966	2,240
Workers' compensation benefits (credit)	(583)	230	(1,212)
Black lung benefits (credit)	5,183	1,719	(189)
Total	$ 14,573	$ 13,388	$ 13,418

ASSET RETIREMENT OBLIGATIONS,80

ASSET RETIREMENT OBLIGATIONS, CONTRACTUAL THIRD-PARTY RECLAMATION RECEIVABLES, AND RECLAMATION DEPOSITS - Summary of Asset Retirement Obligations, Contractual Third-Party Reclamation Receivables, and Reclamation Deposits (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	$ 419,763	$ 452,745	$ 279,864
Contractual Third- Party Reclamation Receivable	94,935
Reclamation Deposits	77,364
Surety bonds outstanding to secure reclamation obligations	384,100
Letters of credit outstanding to secure reclamation obligations	103,200
Coal U.S. Segment [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	251,116
Contractual Third- Party Reclamation Receivable	89,408
Reclamation Deposits	77,364
Coal Canada Segment [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	110,978
Contractual Third- Party Reclamation Receivable	5,527
Reclamation Deposits	0
Coal Westmoreland Resource Partners LP [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	56,634
Contractual Third- Party Reclamation Receivable	0
Reclamation Deposits	0
Power [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	1,035
Contractual Third- Party Reclamation Receivable	0
Reclamation Deposits	$ 0

ASSET RETIREMENT OBLIGATIONS,81

ASSET RETIREMENT OBLIGATIONS, CONTRACTUAL THIRD-PARTY RECLAMATION RECEIVABLES, AND RECLAMATION DEPOSITS - Changes in Company's Asset Retirement Obligations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]
Asset retirement obligations, beginning of period	$ 452,745	$ 279,864
Accretion	38,891	31,033
Liabilities settled	(30,363)	(23,935)
Changes due to amount and timing of reclamation	(24,533)	10,042
ARO acquired	4,146	162,394
Changes due to foreign currency translation	(21,123)	(6,653)
Asset retirement obligations, end of period	419,763	452,745
Less current portion	(43,950)	(43,289)
Asset retirement obligations, less current portion	$ 375,813	$ 409,456

ASSET RETIREMENT OBLIGATIONS,82

ASSET RETIREMENT OBLIGATIONS, CONTRACTUAL THIRD-PARTY RECLAMATION RECEIVABLES, AND RECLAMATION DEPOSITS - Carrying Value and Estimated Fair Value of Reclamation Deposits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Reclamation Deposits		$ 77,364
Gain on available-for-sale securities held as reclamation deposits (less than)	$ 100
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Reclamation Deposits		77,364
Carrying Value [Member] | Cash and cash equivalents [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Reclamation Deposits		45,819
Carrying Value [Member] | Available-for-sale Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Reclamation Deposits		$ 31,545

ASSET RETIREMENT OBLIGATIONS,83

ASSET RETIREMENT OBLIGATIONS, CONTRACTUAL THIRD-PARTY RECLAMATION RECEIVABLES, AND RECLAMATION DEPOSITS - Cost Basis, Gross Unrealized Holding Gains and Fair Value of Available-for-Sale Securities (Detail) - Reclamation Deposits [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Cost basis	$ 31,977	$ 32,930
Gross unrealized holding gains	(521)	(886)
Gross unrealized holding losses	(953)	(428)
Fair Value	$ 31,545	$ 33,388

ASSET RETIREMENT OBLIGATIONS,84

ASSET RETIREMENT OBLIGATIONS, CONTRACTUAL THIRD-PARTY RECLAMATION RECEIVABLES, AND RECLAMATION DEPOSITS - Maturities of Available-for-Sale Securities (Detail) - Reclamation Deposits [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Within one year, Amortized cost	$ 592
Due in five years or less, Amortized cost	16,156
Due after five years to ten years, Amortized cost	6,207
Due in more than ten years, Amortized cost	9,022
Cost basis	31,977	$ 32,930
Within one year, Fair Value	529
Due in five years or less, Fair Value	16,049
Due after five years to ten years, Fair Value	5,925
Due in more than ten years, Fair Value	9,042
Fair value	$ 31,545

DERIVATIVE INSTRUMENTS (Details

DERIVATIVE INSTRUMENTS (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)$ / MWh	Dec. 31, 2014USD ($)	Mar. 31, 2014USD ($)contracts
Not designated as hedging instrument | Foreign Exchange Forward [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Number of forward currency exchange forward contracts | contracts			2
Notional amount			$ 348,300
Not designated as hedging instrument | Foreign Exchange Forward [Member] | Foreign Currency Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Income (expense) recognized in earnings on derivatives	$ 0	$ (6,209)
Not designated as hedging instrument | Power Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Liability	37,335	29,368
Not designated as hedging instrument | Power Contract [Member] | Gain (Loss) on Derivative Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Income (expense) recognized in earnings on derivatives	(5,587)	(31,100)
Other Current Liabilities [Member] | Not designated as hedging instrument | Power Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Liability	13,679	8,265
Other Liabilities [Member] | Not designated as hedging instrument | Power Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Liability	$ 23,656	$ 21,103
Minimum [Member] | Power Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Contracted power price notional amount (in USD per megawatts hour) | $ / MWh	41.05
Maximum [Member] | Power Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Contracted power price notional amount (in USD per megawatts hour) | $ / MWh	55.20
Weighted Average [Member] | Power Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Contracted power price notional amount (in USD per megawatts hour) | $ / MWh	43.93

FAIR VALUE MEASUREMENTS - Estim

FAIR VALUE MEASUREMENTS - Estimated Fair Values of Company's Debt (Detail) - Significant unobservable inputs, Level 3 [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt at fixed interest rate	$ 345,984	$ 345,533
Debt at variable interest rate	619,341	516,300
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt at fixed interest rate	213,500	348,283
Debt at variable interest rate	$ 388,380	$ 519,750

FAIR VALUE MEASUREMENTS - Summa

FAIR VALUE MEASUREMENTS - Summary of Financial Assets at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments included in Reclamation deposits	$ 77,364
Recurring [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments included in Restricted investments and bond collateral	35,813	$ 34,057
Available-for-sale investments included in Reclamation deposits	31,545	33,388
Fair value	67,358	67,445
Recurring [Member] | Significant other observable inputs - Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments included in Restricted investments and bond collateral	0	0
Available-for-sale investments included in Reclamation deposits	0	0
Fair value	0	0
Fair Value [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments included in Restricted investments and bond collateral	35,813
Fair Value [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments included in Restricted investments and bond collateral	35,813	34,057
Available-for-sale investments included in Reclamation deposits	31,545	33,388
Fair value	67,358	67,445
Other Current Liabilities and Other Liabilities [Member] | Recurring [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	(646)	(1,981)
Other Current Liabilities and Other Liabilities [Member] | Recurring [Member] | Significant other observable inputs - Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	(37,335)	(29,368)
Other Current Liabilities and Other Liabilities [Member] | Fair Value [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	(37,981)	(31,349)
Power Contract [Member] | Other Current Liabilities and Other Liabilities [Member] | Recurring [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	0	0
Power Contract [Member] | Other Current Liabilities and Other Liabilities [Member] | Recurring [Member] | Significant other observable inputs - Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	(37,335)	(29,368)
Power Contract [Member] | Other Current Liabilities and Other Liabilities [Member] | Fair Value [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	(37,335)	(29,368)
Warrant [Member] | Other Liabilities [Member] | Recurring [Member] | Quoted prices in active markets for identical assets - Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	$ (646)	$ (1,981)
Warrant [Member] | Other Liabilities [Member] | Recurring [Member] | Significant other observable inputs - Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities
Warrant [Member] | Other Liabilities [Member] | Fair Value [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	$ (646)	$ (1,981)

RESTRICTED STOCK UNITS, STOCK88

RESTRICTED STOCK UNITS, STOCK OPTIONS, AND STOCK APPRECIATION RIGHTS (SARs) - Compensation Expense from Share-Based Arrangements (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Recognition of fair value of restricted stock units, stock options, and stock appreciation rights over vesting period; and issuance of common stock	$ 4,019	$ 4,318	$ 2,967
Contributions of stock to the Company's 401(k) plan	3,729	1,764	2,355
Total share-based compensation expense	$ 7,748	$ 6,082	$ 5,322

RESTRICTED STOCK UNITS, STOCK89

RESTRICTED STOCK UNITS, STOCK OPTIONS, AND STOCK APPRECIATION RIGHTS (SARs) - Summary of Restricted Stock Unit Activity (Detail) - Restricted Stock Units (RSUs) [Member] - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	12 Months Ended
		Apr. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			3 years
Restricted Stock Award Activity (shares) [Roll Forward]
Beginning Balance			409,362
Granted		233,974	262,555
Vested			(256,937)
Forfeited			(60,669)
Ending Balance			354,311	409,362
Restricted Stock, Weighted Average Grant Date Fair Value (in USD per share) [Abstract]
Beginning balance			$ 15.17
Granted			28.26	$ 30.67	$ 11.70
Vested			11.27
Forfeited			11.13
Ending balance			$ 28.44	$ 15.17
Unamortized Compensation Expense	[1]		$ 6,572
Recognition period of unamortized compensation expense (in years)			3 years
Total grant-date fair value of Restricted Stock Units that vested			$ 2,884	$ 3,536	$ 1,689
[1]	Expected to be recognized over the next three years.

RESTRICTED STOCK UNITS, STOCK90

RESTRICTED STOCK UNITS, STOCK OPTIONS, AND STOCK APPRECIATION RIGHTS (SARs) - Summary of Stock Option Activity (Detail) - Stock Options [Member] - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Life of award	10 years
Option Activity (shares) [Roll Forward]
Outstanding at beginning of year	110,806
Exercised	0
Expired	(1,500)
Outstanding at end of year	109,306	110,806
Exercisable at end of year	109,306
Options Outstanding, Weighted Average Exercise Price (in USD per share) [Abstract]
Outstanding at beginning of year	$ 22.15
Exercised
Expired	$ 21.40
Outstanding at end of year	22.16	$ 22.15
Exercisable at end of year	$ 22.16
Options, Outstanding, Weighted Average Remaining Contractual Term (in years)	2 years 2 months 3 days
Options, Exercisable, Weighted Average Remaining Contractual Term (in years)	2 years 2 months 3 days
Intrinsic value of exercises in the period (in USD per share)	$ 0	$ 0	$ 0
Aggregate Intrinsic Value, Outstanding at end of year	0
Aggregate Intrinsic Value, Exercisable at end of year	0
Outstanding and exercisable at end of year Unamortized Compensation Expense	$ 0
Grants in period	0	0	0

RESTRICTED STOCK UNITS, STOCK91

RESTRICTED STOCK UNITS, STOCK OPTIONS, AND STOCK APPRECIATION RIGHTS (SARs) - Summary of Stock Appreciation Rights (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Life of award	10 years
Award vesting period	3 years
Stock Appreciation Rights Activity (shares) [Roll Forward]
Outstanding at beginning of year	110,806
Exercised	0
Expired	(1,500)
Outstanding at end of year	109,306	110,806
Exercisable at end of year	109,306
Stock Appreciation Rights, Weighted Average Exercise Price (in USD per share) [Abstract]
Outstanding at beginning of year	$ 22.15
Exercised
Expired	$ 21.40
Outstanding at end of year	22.16	$ 22.15
Exercisable at end of year	$ 22.16
Options, Outstanding, Weighted Average Remaining Contractual Term (in years)	2 years 2 months 3 days
Options, Exercisable, Weighted Average Remaining Contractual Term (in years)	2 years 2 months 3 days
Aggregate Intrinsic Value, Outstanding at end of year	$ 0
Outstanding and exercisable at end of year Unamortized Compensation Expense	0
Intrinsic value of exercises in the period (in USD per share)	$ 0	$ 0	$ 0
Grants in period	0	0	0
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Life of award	10 years
Award vesting period	3 years
Stock Appreciation Rights Activity (shares) [Roll Forward]
Outstanding at beginning of year	16,943
Exercised	0
Expired	0
Outstanding at end of year	16,943	16,943
Exercisable at end of year	16,943
Stock Appreciation Rights, Weighted Average Exercise Price (in USD per share) [Abstract]
Outstanding at beginning of year	$ 25.44
Exercised
Expired
Outstanding at end of year	$ 25.44	$ 25.44
Exercisable at end of year	$ 25.44
Options, Outstanding, Weighted Average Remaining Contractual Term (in years)	4 months 8 days
Options, Exercisable, Weighted Average Remaining Contractual Term (in years)	4 months 8 days
Aggregate Intrinsic Value, Outstanding at end of year	$ 0
Outstanding and exercisable at end of year Unamortized Compensation Expense	0
Intrinsic value of exercises in the period (in USD per share)	$ 0	$ 11.50		$ 0
Grants in period	0	0	0

RESTRICTED STOCK UNITS, STOCK92

RESTRICTED STOCK UNITS, STOCK OPTIONS, AND STOCK APPRECIATION RIGHTS Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Apr. 30, 2015	Dec. 31, 2015
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units, Granted (shares)	233,974	262,555
Amended And Restated 2007 Equity Incentive Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non Employee Directors Annual Equity Awards Amount		$ 90,000
2007 Incentive Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (shares)		296,431
2014 Incentive Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (shares)		526,460
Vesting Ratably Over Vesting Period [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units, Granted (shares)	117,003
Award vesting rights	P3Y
Performance Based [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units, Granted (shares)	116,971
Award vesting rights	three

STOCKHOLDERS' EQUITY AND ACCU93

STOCKHOLDERS' EQUITY AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Noncontrolling Interest (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Noncontrolling Interest [Line Items]
Noncontrolling interest acquired		$ 15,300
Noncontrolling interest, ownership percentage by noncontrolling owners (percent)		21.00%
Noncontrolling interest, increase in ownership percentage (percent)		15.00%
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	$ 15,261
Net loss allocated to noncontrolling interest	(208,767)	$ (173,180)	$ (8,127)
Distributions to noncontrolling interest	797
Other	0
Ending balance	732	15,261
Noncontrolling Interest [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Change in Parent's ownership	(8,279)
Net loss allocated to noncontrolling interest	(5,453)	$ (921)	$ (3,430)
Distributions to noncontrolling interest	$ 797

STOCKHOLDERS' EQUITY AND ACCU94

STOCKHOLDERS' EQUITY AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Additional Information (Detail) $ / shares in Units, $ in Thousands	1 Months Ended	2 Months Ended	12 Months Ended
	Jul. 16, 2014USD ($)$ / sharesshares	Feb. 25, 2015shares	Dec. 31, 2015USD ($)class_of_stock$ / sharesshares	Dec. 31, 2014USD ($)$ / shares	Dec. 31, 2013USD ($)
Class of Stock [Line Items]
Restricted net assets not available for transfer			$ 13,200
Number of classes of capital stock | class_of_stock			1
Common stock, par value (in USD per share) | $ / shares			$ 0.01	$ 2.50
Preferred stock dividends paid (less than)			$ 3	$ 859	$ 1,360
Proceeds from issuance of common shares			$ 0	$ 56,473	$ 0
Preferred Stock [Member]
Class of Stock [Line Items]
Conversion of stock, shares converted (shares) | shares			88,494
Shares redeemed (shares) | shares		3,175
Shares issued for redeemed stock (shares) | shares		300,000
Preferred stock dividends paid (less than)			$ 100
Common Stock [Member]
Class of Stock [Line Items]
Conversion of stock, shares issued (shares) | shares			604,557
Shares issued in public offering (shares) | shares	1,684,507
Shares issued in public offering, price per share (in USD per share) | $ / shares	$ 35.50
Proceeds from issuance of common shares	$ 59,800
Stock issued in public offering, brokerage fees (in USD per share) | $ / shares	$ 1.775
Stock issued in public offering, brokerage fees	$ 3,000
Legal and other fees associated with the public offering	$ 300

STOCKHOLDERS' EQUITY AND ACCU95

STOCKHOLDERS' EQUITY AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity [Abstract]
Pension and Postretirement Medical Benefits	$ (65,644)	$ (75,781)	$ (32,547)	$ (122,246)
Available for Sale Securities	(1,325)	413	0	57
Foreign currency translation adjustment	(69,901)	(17,880)	0	0
Tax Effect of Other Comprehensive Income Gains	(34,430)	(31,048)	(31,048)	(26,156)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(171,300)	(124,296)	(63,595)	$ (148,345)
Pension And Postretirement Medical Benefits	10,137	(43,234)	89,699
Available For Sale Securities	(1,738)	413	(57)
Foreign Currency Translation Adjustment	(52,021)	(17,880)	0
Tax effect of other comprehensive income gains	(3,382)	0	(4,892)
Other comprehensive income (loss)	$ (47,004)	$ (60,701)	$ 84,750

STOCKHOLDERS' EQUITY AND ACCU96

STOCKHOLDERS' EQUITY AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Changes in Accumulated Other Comprehensive Income by component (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	$ (124,296)
Other comprehensive income before reclassifications	(50,821)
Amounts reclassified from accumulated other comprehensive income (loss)	3,817
Balance at end of period	(171,300)
Accumulated Defined Benefit Plans Adjustment [Member] | Postretirement Medical Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(39,716)
Other comprehensive income before reclassifications	7,322
Amounts reclassified from accumulated other comprehensive income (loss)	1,308
Balance at end of period	(31,086)
Accumulated Defined Benefit Plans Adjustment [Member] | Pension Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(36,065)
Other comprehensive income before reclassifications	(853)
Amounts reclassified from accumulated other comprehensive income (loss)	2,360
Balance at end of period	(34,558)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	413
Other comprehensive income before reclassifications	(1,887)
Amounts reclassified from accumulated other comprehensive income (loss)	149
Balance at end of period	(1,325)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(17,880)
Other comprehensive income before reclassifications	(52,021)
Amounts reclassified from accumulated other comprehensive income (loss)	0
Balance at end of period	(69,901)
Tax Effect of Other Comprehensive Income Gains [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(31,048)
Other comprehensive income before reclassifications	(3,382)
Amounts reclassified from accumulated other comprehensive income (loss)	0
Balance at end of period	$ (34,430)

STOCKHOLDERS' EQUITY AND ACCU97

STOCKHOLDERS' EQUITY AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Unrealized and realized gains and losses on available-for-sale securities		$ (1,738)	$ 413	$ (57)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Unrealized and realized gains and losses on available-for-sale securities	[1]	149
Other Income [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, before Tax	[1]	149
Postretirement Medical Benefits [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax	[1],[2]	1,944
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Prior Service Cost, before Tax	[1],[2]	(636)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	[1]	1,308
Pension Benefits [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Gain (Loss), before Tax	[1],[3]	2,352
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss), Net Prior Service Cost, before Tax	[1],[3]	8
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	[1]	$ 2,360
[1]	Amounts in parentheses indicate debits to income/loss.
[2]	These accumulated other comprehensive income components are included in the computation of net periodic postretirement medical cost.
[3]	These accumulated other comprehensive income components are included in the computation of net periodic pension cost.

INCOME TAX - U.S. and foreign i

INCOME TAX - U.S. and foreign income before taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Income (loss) before income taxes, U.S.	$ (254,252)	$ (157,043)	$ (12,909)
Income (loss) before income taxes, Foreign	25,718	(15,905)	0
Loss before income taxes	$ (228,534)	$ (172,948)	$ (12,909)

INCOME TAX - Components of Inco

INCOME TAX - Components of Income Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current:
Current federal taxes	$ 0	$ 0	$ (2)
Current state taxes	12	120	112
Current foreign taxes	1,441	545	0
Current tax expense (benefit)	1,453	665	110
Deferred:
Deferred federal taxes	(3,295)	0	(4,189)
Deferred state taxes	(330)	0	(703)
Deferred foreign taxes	(17,595)	(433)	0
Deferred tax expense (benefit)	(21,220)	(433)	(4,892)
Income tax benefit	$ (19,767)	$ 232	$ (4,782)

INCOME TAX - Reconciliation of

INCOME TAX - Reconciliation of Effective Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Computed tax benefit at statutory rate	$ (82,022)	$ (58,066)	$ (4,390)
Increase (decrease) in tax expense resulting from:
Tax depletion in excess of basis	(5,317)	(9,273)	(6,187)
Non-deductible acquisition costs	0	2,979	0
Non-deductible interest expense	(6,488)	(4,174)	1,167
State income taxes, net	(6,184)	(9,706)	3,696
Adjustments to deferred tax assets and liabilities attributable to prior years	4,244	0	489
Change in valuation allowance for net deferred tax assets	132,338	77,771	15
Release of valuation allowance arising from amalgamation	(32,635)	0	0
Indian Coal Tax Credits	(13,756)	(15,205)	92
Change in Canadian rate	(3,081)	0	0
Kemmerer deferred tax asset removal	(13,238)	0	0
Uncertain tax positions	3,994	0	0
Other, net	6,622	15,906	825
Income tax benefit	$ (19,767)	$ 232	$ (4,782)

INCOME TAX - Components of Defe

INCOME TAX - Components of Deferred Tax Assets And Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Federal net operating loss carryforwards	$ 198,216	$ 166,489
Deferred Tax Assets, Tax Credit Carryforwards	62,219	47,872
Investment in WMLP	3,112	1,185
Accrued compensation and benefits	5,847	2,592
Asset retirement obligations	92,889	101,514
Postretirement medical benefit and pension obligations	123,595	124,854
Deferred revenues	13,591	15,841
Black lung accrual	7,405	4,244
Unrealized gain/(loss) on derivatives	14,377	11,078
Canadian resource pool	4,088	6,435
Lease obligations	13,341	23,401
Depreciable capital assets	0	6,779
Other	5,896	13,514
Total gross deferred assets	544,576	525,798
Valuation allowance	(497,796)	(406,143)
Net deferred tax assets	46,780	119,655
Deferred tax liabilities:
Property, plant and equipment, differences due to depreciation and amortization	(26,061)	(113,430)
Investment in Joint Venture	(6,284)	(7,324)
Finance lease receivable	(9,446)	(15,232)
Deferred reclamation revenue	(1,492)	(1,688)
Other	(3,497)	(3,750)
Total gross deferred tax liabilities	(46,780)	(141,424)
Net deferred tax asset (liability)	$ 0	$ 21,769

INCOME TAX - Additional Informa

INCOME TAX - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Loss Carryforwards [Line Items]
Net valuation allowance increase	$ 91,700,000	$ 141,700,000
ICTC carryforwards	54,500,000
Uncertain tax positions	3,994,000	0	$ 0
Penalties and interest expense	0	$ 0	$ 0
Uncertain tax positions expected to change in next 12 months	0
Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	417,300,000
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 92,900,000

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Leases (Details) $ in Thousands, gal in Millions	12 Months Ended
	Dec. 31, 2015USD ($)gal	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Future minimum capital lease payments:
2,016	$ 35,467
2,017	27,695
2,018	6,497
2,019	4,336
2,020	1,297
Thereafter	0
Total minimum lease payments	75,292
Less imputed interest	(4,124)
Present value of minimum capital lease payments	71,168
Future minimum operating lease payments:
2,016	12,390
2,017	7,409
2,018	5,488
2,019	4,421
2,020	660
Thereafter	2,360
Total	32,728
Rental expense under operating leases	25,200	$ 16,600	$ 11,800
Royalty expense, coal reserves	$ 96,700	61,800	$ 43,600
Minimum annual purchase requirement (in gallons of diesel fuel) | gal	3.9
Property, plant and equipment and mine development assets [Member]
Gross value and accumulated amortization of assets under capital leases:
Gross value	$ 65,293	74,203
Accumulated amortization	25,878	$ 21,598
Other Current Liabilities [Member]
Gross value and accumulated amortization of assets under capital leases:
Remediation obligation	$ 8,100

BUSINESS SEGMENT INFORMATION -

BUSINESS SEGMENT INFORMATION - Summarized Financial Information by Segment (Detail)		3 Months Ended									12 Months Ended
		Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2014USD ($)		Sep. 30, 2014USD ($)	Jun. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Dec. 31, 2015USD ($)segments	Dec. 31, 2014USD ($)		Dec. 31, 2013USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | segments											6
Revenues											$ 1,411,048,000	$ 1,115,992,000		$ 674,686,000
Restructuring charges											656,000	14,989,000		5,078,000
Depreciation, depletion, and amortization											131,491,000	100,778,000		67,231,000
Operating income (loss)		$ (118,623,000)	$ (15,307,000)	$ (6,866,000)	$ 8,455,000	$ 8,044,000		$ (29,432,000)	$ (29,640,000)	$ 8,053,000	(132,341,000)	(42,975,000)		25,362,000
Total assets		1,502,396,000				1,816,495,000					1,502,396,000	1,816,495,000		941,330,000
Capital expenditures											77,921,000	50,326,000		28,591,000
Coal Segment [Member]
Segment Reporting Information [Line Items]
Revenues	[1],[2]										544,172,000	471,567,000		414,652,000
Restructuring charges	[1],[2]										0	1,058,000		0
Depreciation, depletion, and amortization	[1],[2]										37,507,000	37,651,000		38,956,000
Operating income (loss)	[1],[2]										12,107,000	(5,078,000)		15,744,000
Total assets	[1],[2]	520,467,000				475,999,000					520,467,000	475,999,000		511,675,000
Capital expenditures	[1],[2]										25,193,000	23,108,000		21,045,000
Coal Canada Segment [Member]
Segment Reporting Information [Line Items]
Revenues	[3]										430,519,000	388,664,000		0
Restructuring charges	[3]										0	9,565,000		0
Depreciation, depletion, and amortization	[3]										29,629,000	36,068,000		0
Operating income (loss)	[3]										40,291,000	(2,670,000)		0
Total assets	[3]	506,139,000				626,620,000					506,139,000	626,620,000		0
Capital expenditures	[3]										27,658,000	19,147,000		0
Westmoreland Resource Partners LP [Member]
Segment Reporting Information [Line Items]
Revenues	[4],[5]										388,605,000	170,508,000	[1]	172,467,000	[1]
Restructuring charges	[4],[5]										656,000	2,783,000		0
Depreciation, depletion, and amortization	[4],[5]										54,504,000	16,912,000	[1]	17,742,000	[1]
Operating income (loss)	[1],[4],[5]										(5,211,000)	26,478,000		28,726,000
Total assets	[4],[5]	420,907,000				482,379,000	[1]				420,907,000	482,379,000	[1]	194,141,000	[1]
Capital expenditures	[4],[5]										27,296,000	7,489,000	[1]	6,019,000	[1]
Power [Member]
Segment Reporting Information [Line Items]
Revenues											84,423,000	85,253,000		87,567,000
Restructuring charges											0	459,000		5,078,000
Depreciation, depletion, and amortization											9,908,000	9,998,000		10,179,000
Operating income (loss)											(146,868,000)	(35,023,000)		4,908,000
Total assets		39,762,000				172,104,000					39,762,000	172,104,000		180,684,000
Capital expenditures											1,408,000	527,000		790,000
Heritage [Member]
Segment Reporting Information [Line Items]
Revenues											0	0		0
Restructuring charges											0	78,000		0
Depreciation, depletion, and amortization											0	0		0
Operating income (loss)											(15,596,000)	(14,858,000)		(14,498,000)
Total assets		16,146,000				15,969,000					16,146,000	15,969,000		15,497,000
Capital expenditures											0	0		0
Corporate [Member]
Segment Reporting Information [Line Items]
Revenues	[6]										(36,671,000)	0		0
Restructuring charges	[6]										0	1,046,000		0
Depreciation, depletion, and amortization	[6]										(57,000)	149,000		354,000
Operating income (loss)	[6]										(17,064,000)	(11,824,000)		(9,518,000)
Total assets	[6]	$ (1,025,000)				$ 43,424,000					(1,025,000)	43,424,000		39,333,000
Capital expenditures	[6]										(3,634,000)	55,000		$ 737,000
Buckingham Coal Company, LLC [Member]
Segment Reporting Information [Line Items]
Revenues											80,400,000
Operating income (loss)											3,200,000
Ohio Operations [Member]
Segment Reporting Information [Line Items]
Revenues												225,200,000
Operating income (loss)												$ 26,800,000
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues											$ 30,900,000
[1]	Financial information of the Kemmerer mine for the year ended December 31, 2014 and 2013 was previously presented under the Coal - U.S. segment and is now presented under the Coal - WMLP segment for all periods presented due to the Kemmerer Drop that occurred on August 1, 2015.
[2]	The Buckingham Acquisition was completed on January 1, 2015. For the year ended December 31, 2015, revenues for Buckingham were $80.4 million and operating losses were $3.2 million.
[3]	The Canadian operations were acquired on April 28, 2014, therefore, information for the year ended December 31, 2014 includes approximately eight months of operations and there is no activity for 2013.
[4]	The Coal - WMLP segment recorded revenues of $30.9 million for intersegment revenues to the Coal - U.S. segment for the year ended December 31, 2015.
[5]	The Ohio operations reported under the segment Coal - WMLP were acquired on December 31, 2014. For the year ended December 31, 2015, revenues for the Ohio operations were $225.2 million and operating losses were $26.8 million.
[6]	Eliminations for intersegment revenues and cost of sales are presented within the Corporate segment.

BUSINESS SEGMENT INFORMATION105

BUSINESS SEGMENT INFORMATION - Reconciliation of Segment Operating Income to Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting [Abstract]
Income (loss) from operations	$ (118,623)	$ (15,307)	$ (6,866)	$ 8,455	$ 8,044	$ (29,432)	$ (29,640)	$ 8,053	$ (132,341)	$ (42,975)	$ 25,362
Interest expense									(104,215)	(84,234)	(39,937)
Loss on extinguishment of debt									(5,385)	(49,154)	(64)
Interest income									7,993	6,400	1,366
Gain (loss) on foreign exchange									3,674	(4,016)	0
Other income									1,740	1,031	364
Loss before income taxes									$ (228,534)	$ (172,948)	$ (12,909)

BUSINESS SEGMENT INFORMATION106

BUSINESS SEGMENT INFORMATION - Customer Concentration Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Revenue, Major Customer [Line Items]
Revenues	$ 340,810	$ 349,796	$ 348,959	$ 371,483	$ 310,004	$ 337,830	$ 287,956	$ 180,202	$ 1,411,048		$ 1,115,992	$ 674,686
Total Revenue [Member] | Customer Concentration Risk [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Percentage									63.16483%	[1]	57.3246%	72.8029%
Customer A [Member] | Coal Segment [Member]
Revenue, Major Customer [Line Items]
Revenues									$ 203,942	[1]	$ 0	$ 0
Customer B [Member] | Coal Canada Segment [Member]
Revenue, Major Customer [Line Items]
Revenues									180,660	[1]	144,863	0
Customer C [Member] | Coal Segment [Member]
Revenue, Major Customer [Line Items]
Revenues									153,585	[1]	128,104	117,545
Customer D [Member] | Coal Segment [Member]
Revenue, Major Customer [Line Items]
Revenues									103,752	[1]	101,778	112,061
Customer E [Member] | Coal Segment [Member]
Revenue, Major Customer [Line Items]
Revenues									97,449	[1]	100,234	89,266
Customer F [Member] | Power [Member]
Revenue, Major Customer [Line Items]
Revenues									84,423	[1]	85,254	86,390
Customer G [Member] | Coal Segment [Member]
Revenue, Major Customer [Line Items]
Revenues									$ 67,475	[1]	$ 79,505	$ 85,929
[1]	The revenue from Customers D, E, F, and G did not exceed 10% in 2015 and 2014.

QUARTERLY FINANCIAL DATA (UN107

QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 340,810	$ 349,796	$ 348,959	$ 371,483	$ 310,004	$ 337,830	$ 287,956	$ 180,202	$ 1,411,048	$ 1,115,992	$ 674,686
Operating income (loss)	(118,623)	(15,307)	(6,866)	8,455	8,044	(29,432)	(29,640)	8,053	(132,341)	(42,975)	25,362
Net Income (loss) applicable to common shareholders	$ (108,418)	$ (46,562)	$ (36,605)	$ (11,732)	$ (41,135)	$ (49,329)	$ (63,363)	$ (19,291)	$ (203,317)	$ (173,118)	$ (6,057)
Basic income (loss) per common share	$ (6)	$ (2.59)	$ (2.04)	$ (0.67)	$ (2.41)	$ (2.95)	$ (4.19)	$ (1.30)

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - San Juan Coal Company [Member] - Subsequent Event [Member] $ in Millions	Jan. 31, 2016USD ($)
Acquisition [Abstract]
Cash purchase price paid by Westmoreland San Juan, LLC	$ 127
Loan for acquisition	$ 125
Spread on basis, percentage	7.25%