Arch Resources (ARCH) 10-K 15 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Feb. 13, 2016	Jun. 30, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	ARCH COAL INC
Entity Central Index Key	1,037,676
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		21,446,233
Entity Well known seasoned issuer	Yes
Entity Voluntary Filers	No
Entity Current reporting status	Yes
Entity Public Float			$ 72.4

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues	$ 2,573,260	$ 2,937,119	$ 3,014,357
Costs, expenses and other operating
Cost of sales (exclusive of items shown separately below)	2,206,433	2,566,193	2,663,136
Depreciation, depletion and amortization	379,345	418,748	426,442
Amortization of acquired sales contracts, net	(8,811)	(13,187)	(9,457)
Change in fair value of coal derivatives and coal trading activities, net	(1,583)	(3,686)	7,845
Asset impairment and mine closure costs	2,628,303	24,113	220,879
Goodwill impairment	0	0	265,423
Losses from disposed operations resulting from Patriot Coal bankruptcy	116,343	0	0
Selling, general and administrative expenses	98,783	114,223	133,448
Other operating expense (income), net	19,510	(19,754)	(30,218)
Total operating expenses	5,438,323	3,086,650	3,677,498
Loss from operations	(2,865,063)	(149,531)	(663,141)
Interest expense, net
Interest expense	(397,979)	(390,946)	(381,267)
Interest and investment income	4,430	7,758	6,603
Interest expense, net	(393,549)	(383,188)	(374,664)
Nonoperating expense
Net loss resulting from early retirement of debt and debt restructuring	(27,910)	0	(42,921)
Loss from continuing operations before income taxes	(3,286,522)	(532,719)	(1,080,726)
Provision for (benefit from) income taxes	(373,380)	25,634	(335,498)
Loss from continuing operations	(2,913,142)	(558,353)	(745,228)
Income from discontinued operations, including gain on sale - net of tax	0	0	103,396
Net loss	$ (2,913,142)	$ (558,353)	$ (641,832)
Losses per common share
Basic and diluted LPS- Loss from continuing operations (in dollars per share)	$ (136.86)	$ (26.31)	$ (35.15)
Basic and diluted LPS - Net loss (in dollars per share)	$ (136.86)	$ (26.31)	$ (30.26)
Weighted average shares outstanding
Basic and diluted weighted average shares outstanding	21,285	21,222	21,210
Dividends declared per common share (in dollars per share)	$ 0	$ 0.1	$ 1.2

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	$ (2,913,142)	$ (558,353)	$ (641,832)
Derivative instruments
Comprehensive income (loss) before tax	(3,477)	3,102	(2,626)
Income tax benefit (provision)	1,252	(1,117)	947
Derivatives Qualifying as Hedges, Adjustment, Net of Tax	(2,225)	1,985	(1,679)
Pension, postretirement and other post-employment benefits
Comprehensive income (loss) before tax	(5,592)	(44,143)	77,201
Income tax benefit (provision)	2,011	15,891	(27,803)
Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(3,581)	(28,252)	49,398
Available-for-sale securities
Comprehensive income (loss) before tax	1,185	(12,788)	10,190
Income tax benefit (provision)	(435)	4,604	(3,710)
Available-for-sale Securities Adjustment, Net of Tax	750	(8,184)	6,480
Total other comprehensive income (loss)	(5,056)	(34,451)	54,199
Total comprehensive loss	$ (2,918,198)	$ (592,804)	$ (587,633)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 450,781	$ 734,231
Short term investments	200,192	248,954
Restricted cash	97,542	5,678
Trade accounts receivable (net of allowance for doubtful accounts of $7.8 million and $0.2 million, respectively)	117,405	211,506
Other receivables	18,362	20,511
Inventories	196,720	190,253
Prepaid royalties	10,022	11,118
Deferred income taxes	0	52,728
Coal derivative assets	8,035	13,257
Other current assets	104,723	54,515
Total current assets	1,203,782	1,542,751
Property, plant and equipment
Coal lands and mineral rights	3,713,639	6,040,656
Plant and equipment	2,359,674	2,935,381
Deferred mine development	553,286	891,649
Property, plant and equipment, gross	6,626,599	9,867,686
Less accumulated depreciation, depletion and amortization	(3,007,570)	(3,414,228)
Property, plant and equipment, net	3,619,029	6,453,458
Other assets
Prepaid royalties	23,671	66,806
Equity investments	201,877	235,842
Other noncurrent assets	58,379	130,866
Total other assets	283,927	433,514
Total assets	5,106,738	8,429,723
Current liabilities
Accounts payable	128,131	180,113
Accrued expenses and other current liabilities	329,450	302,396
Current maturities of debt	5,107,210	36,885
Total current liabilities	5,564,791	519,394
Long-term debt	30,953	5,123,485
Asset retirement obligations	396,659	398,896
Accrued pension benefits	27,373	16,260
Accrued postretirement benefits other than pension	99,810	32,668
Accrued workers’ compensation	112,270	94,291
Deferred income taxes	0	422,809
Other noncurrent liabilities	119,171	153,766
Total liabilities	6,351,027	6,761,569
Stockholders' equity (deficit)
Common stock, $0.01 par value, authorized 26,000 shares, issued 21,446 and 21,379 shares at December 31, 2015 and 2014, respectively	2,145	2,141
Paid-in capital	3,054,211	3,048,460
Treasury stock, at cost	(53,863)	(53,863)
Accumulated deficit	(4,244,967)	(1,331,825)
Accumulated other comprehensive income	(1,815)	3,241
Total stockholders’ equity (deficit)	(1,244,289)	1,668,154
Total liabilities and stockholders’ equity (deficit)	$ 5,106,738	$ 8,429,723

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 7.8	$ 0.2
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	26,000,000	26,000,000
Common stock, shares issued	21,291,000	21,225,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activties
Net loss	$ (2,913,142)	$ (558,353)	$ (641,832)
Adjustments to reconcile net loss to cash provided by operating activities:
Depreciation, depletion and amortization	379,345	418,748	447,704
Amortization of acquired sales contracts, net	(8,811)	(13,187)	(9,457)
Prepaid royalties expensed	8,109	9,698	13,706
Deferred income taxes	(367,210)	25,152	(263,099)
Employee stock-based compensation expense	5,760	9,847	11,790
Gains on disposals and divestitures	(2,270)	(27,512)	(120,321)
Asset impairment and noncash mine closure costs	2,613,345	16,868	220,879
Goodwill impairment	0	0	265,423
Losses from disposed operations resulting from Patriot Coal bankruptcy	116,343	0	0
Amortization relating to financing activities	25,241	17,363	24,789
Net loss resulting from early retirement of debt and debt restructuring	27,910	0	42,921
Changes in:
Receivables	98,212	(8,991)	62,881
Inventories	(6,534)	41,548	44,635
Coal derivative assets and liabilities	973	5,449	3,606
Accounts payable, accrued expenses and other current liabilities	(15,532)	41,680	(78,126)
Asset retirement obligations	16,640	18,288	17,432
Pension, postretirement and other postemployment benefits	4,800	(25,347)	7,284
Other	(27,546)	(4,833)	5,527
Cash provided by (used in) operating activities	(44,367)	(33,582)	55,742
Investing activities
Capital expenditures	(119,024)	(147,286)	(296,984)
Minimum royalty payments	(5,871)	(7,317)	(14,947)
Proceeds from sale-leaseback transactions	0	0	34,919
Proceeds from disposals and divestitures	2,191	62,358	433,453
Purchases of short term investments	(246,735)	(211,929)	(213,726)
Proceeds from sales of short term investments	290,205	205,611	194,537
Proceeds from sale of investments in equity investments and securities	2,259	9,464	0
Investments in and advances to affiliates, net	(11,502)	(16,657)	(15,260)
Withdrawals (deposits) of restricted cash	(91,864)	(5,678)	3,453
Cash provided by (used in) investing activities	(180,341)	(111,434)	125,445
Financing activities
Proceeds from term loan	0	0	294,000
Proceeds from issuance of senior notes	0	0	350,000
Payments to retire debt	0	(300)	(628,660)
Payments on term loan	(19,500)	(19,500)	(17,250)
Net payments on other debt	(11,332)	(5,395)	(6,836)
Debt financing costs	0	(4,519)	(20,489)
Dividends paid	0	(2,123)	(25,475)
Expenses related to debt restructuring	(27,910)	0	0
Other	0	(15)	0
Cash used in financing activities	(58,742)	(31,852)	(54,710)
Increase (decrease) in cash and cash equivalents	(283,450)	(176,868)	126,477
Cash and cash equivalents, beginning of period	734,231	911,099	784,622
Cash and cash equivalents, end of period	450,781	734,231	911,099
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid during the year for interest	283,337	361,727	380,389
Cash refunded during the year for income taxes, net	$ 4,138	$ 4,896	$ 18,741

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock [Member]	Paid-in Capital [Member]	Treasury Stock, at Cost [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2012	$ 2,854,567	$ 2,141	$ 3,026,823	$ (53,848)	$ (104,042)	$ (16,507)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)	(587,633)				(641,832)	54,199
Dividends on common shares	(25,475)				(25,475)
Issuance of shares of common stock under the stock incentive plan — restricted stock and restricted stock units, net of forfeitures	0	0	0
Employee stock-based compensation expense	11,790		11,790
Ending Balance at Dec. 31, 2013	2,253,249	2,141	3,038,613	(53,848)	(771,349)	37,692
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)	(592,804)				(558,353)	(34,451)
Dividends on common shares	(2,123)				(2,123)
Treasury shares purchased	(15)	0	0	(15)
Employee stock-based compensation expense	9,847		9,847
Ending Balance at Dec. 31, 2014	1,668,154	2,141	3,048,460	(53,863)	(1,331,825)	3,241
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)	(2,918,198)				(2,913,142)
Issuance of shares of common stock under the stock incentive plan — restricted stock and restricted stock units, net of forfeitures	(5)	4	(9)
Employee stock-based compensation expense	5,760
Ending Balance at Dec. 31, 2015	$ (1,244,289)	$ 2,145	$ 3,054,211	$ (53,863)	$ (4,244,967)	$ (1,815)

Consolidated Statements of Sto8

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2013
Statement of Stockholders' Equity [Abstract]
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	0	39
Dividends declared per common share (in dollars per share)	$ 0	$ 1.2

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements include the accounts of Arch Coal, Inc. and its subsidiaries and controlled entities (the “Company”). The Company’s primary business is the production of thermal and metallurgical coal from surface and underground mines located throughout the United States, for sale to utility, industrial and steel producers both in the United States and around the world. The Company currently operates mining complexes in West Virginia, Kentucky, Maryland, Virginia, Illinois, Wyoming and Colorado. All subsidiaries are wholly-owned. Intercompany transactions and accounts have been eliminated in consolidation. Filing Under Chapter 11 of the United States Bankruptcy Code On January 11, 2016 (the “Petition Date”), Arch and substantially all of its wholly owned domestic subsidiaries (the “Filing Subsidiaries” and, together with Arch, the “Debtors”) filed voluntary petitions for reorganization (collectively, the “Bankruptcy Petitions”) under Chapter 11 of Title 11 of the U.S. Code (the “Bankruptcy Code”) in the United States Bankruptcy Court for the Eastern District of Missouri (the “Court”). The Debtor’s Chapter 11 Cases (collectively, the “Chapter 11 Cases”) are being jointly administered under the caption In re Arch Coal, Inc., et al. Case No. 16-40120 (lead case). Each Debtor will continue to operate its business as a “debtor in possession” under the jurisdiction of the Court and in accordance with the applicable provisions of the Bankruptcy Code and the orders of the Court. The filing of the Bankruptcy Petitions constituted an event of default that accelerated Arch’s obligations under the documents governing each of Arch’s 7.00% senior notes due 2019, 9.875% senior notes due 2019, 8.00% senior secured second lien notes due 2019, 7.25% senior notes due 2020, 7.25% senior notes due 2021 (together, the “senior notes”) and senior secured first lien term loan due 2018 (the “Existing Credit Agreement”) (collectively with the senior notes, the “Debt Instruments”), all as further described in Note 14, "Debt and Financing Arrangements" to the Consolidated Financial Statements included in the Form 10-K. Immediately after filing the Bankruptcy Petitions, Arch began notifying all known current or potential creditors of the Debtors of the bankruptcy filings. Additionally, on the Petition Date, the New York Stock Exchange (the “NYSE”) determined that the Company's stock was no longer suitable for listing pursuant to Section 8.02.01D of the NYSE continued listing standards and trading in the Company’s common stock was suspended on January 11, 2016. We expect that the existing common stock of the Company will be extinguished upon the Company's emergence from Chapter 11 and existing equity holders will not receive consideration in respect of their equity interests. On the Petition Date, the Debtors filed a number of motions with the Court generally designed to stabilize their operations and facilitate the Debtors’ transition into Chapter 11. Certain of these motions sought authority from the Court for the Debtors to make payments upon, or otherwise honor, certain pre-petition obligations (e.g., obligations related to certain employee wages, salaries and benefits and certain vendors and other providers essential to the Debtors’ businesses). The Court has entered orders approving the relief sought in these motions, in certain cases on an interim basis. Pursuant to Section 362 of the Bankruptcy Code, the filing of the Bankruptcy Petitions automatically stayed most actions against the Debtors, including actions to collect indebtedness incurred prior to the Petition Date or to exercise control over the Debtors’ property. Subject to certain exceptions under the Bankruptcy Code, the filing of the Debtors’ Chapter 11 Cases also automatically stayed the continuation of most legal proceedings, including the third party litigation matters described under “Legal Proceedings,” or the filing of other actions against or on behalf of the Debtors or their property to recover on, collect or secure a claim arising prior to the Petition Date or to exercise control over property of the Debtors’ bankruptcy estates, unless and until the Court modifies or lifts the automatic stay as to any such claim. Notwithstanding the general application of the automatic stay described above, governmental authorities may determine to continue actions brought under their police and regulatory powers. As required by the Bankruptcy Code, the U.S. Trustee for the Eastern District of Missouri appointed an official committee of unsecured creditors (the “Creditors’ Committee”) on January 25, 2016. The Creditors’ Committee represents all unsecured creditors of the Debtors and has a right to be heard on all matters that come before the Court. As a result of extremely challenging current market conditions, the Company believes it will require a significant restructuring of its balance sheet in order to continue as a going concern in the long term. The Company’s ability to continue as a going concern is dependent upon, among other things, improvement in current market conditions, its ability to become profitable and maintain profitability and its ability to successfully implement its Chapter 11 plan strategy. As a result of the Bankruptcy Petitions, the realization of the Debtors’ assets and the satisfaction of liabilities are subject to significant uncertainty. While operating as a debtor-in-possession pursuant to the Bankruptcy Code, the Company may sell or otherwise dispose of or liquidate assets or settle liabilities, subject to the approval of the Court or as otherwise permitted in the ordinary course of business for amounts other than those reflected in the accompanying consolidated financial statements. Further, a Chapter 11 plan is likely to materially change the amounts and classifications of assets and liabilities reported in the Company’s Consolidated Financial Statements. On August 4, 2015, the Company effected a 1-for-10 reverse stock split of its common stock. Each stockholder's percentage ownership and proportional voting power remain unchanged as a result of the reverse stock split. All applicable share data, per share amounts and related information in the Consolidated Financial Statements and notes thereto have been adjusted retroactively to give effect to the 1-for-10 reverse stock split. The Company completed the sale of Canyon Fuel Company, LLC (Canyon Fuel) on August 16, 2013. The results of these mining complexes have been segregated from continuing operations and are reflected, net of tax, as discontinued operations in the consolidated statements of operations for 2013. See further discussion in Note 3 , " Divestitures ". In response to weak coal markets, the Company has idled or closed mines in the Appalachia region and sold other non-core operating subsidiaries and assets. The results from these operations and gains or losses on the disposal are reflected in income from continuing operations in the consolidated statements of operations. See further discussion in Note 5 , " Impairment Charges and Mine Closure Costs ".

Accounting Policies

Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Accounting Policies	Accounting Policies The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for financial reporting and U.S. Securities and Exchange Commission regulations. Accounting Pronouncements There are no accounting pronouncements whose adoption had, or is expected to have, a material impact on the Company's consolidated financial statements. Accounting Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and revenues and expenses in the accompanying consolidated financial statements and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates. Cash and Cash Equivalents Cash and cash equivalents are stated at cost. Cash equivalents consist of highly-liquid investments with an original maturity of three months or less when purchased. Restricted cash Restricted cash represents cash collateral supporting letters of credit issued under the Company's accounts receivable securitization program. Accounts Receivable Accounts receivable are recorded at amounts that are expected to be collected, based on past collection history, the economic environment and specified risks identified in the receivables portfolio. Inventories Coal and supplies inventories are valued at the lower of average cost or market. Coal inventory costs include labor, supplies, equipment costs, transportation costs incurred prior to the transfer of title to customers and operating overhead. The costs of removing overburden, called stripping costs, incurred during the production phase of the mine are considered variable production costs and are included in the cost of the coal extracted during the period the stripping costs are incurred. Investments and Membership Interests in Joint Ventures Investments and membership interests in joint ventures are accounted for under the equity method of accounting if the Company has the ability to exercise significant influence, but not control, over the entity. The Company's share of the entity's income or loss is reflected in " Other operating expense (income), net " in the consolidated statements of operations. Information about investment activity is provided in Note 10 , " Equity Method Investments and Membership Interests in Joint Ventures ". Investments in debt securities and marketable equity securities that do not qualify for equity method accounting are classified as available-for-sale and are recorded at their fair values. Unrealized gains and losses on these investments are recorded in other comprehensive income or loss. A decline in the value of an investment that is considered other-than-temporary would be recognized in operating expenses. Acquired Sales Contracts Coal supply agreements (sales contracts) acquired in a business combination are capitalized at their fair value and amortized over the tons of coal shipped during the term of the contract. The fair value of a sales contract is determined by discounting the cash flows attributable to the difference between the contract price and the prevailing forward prices for the tons under contract at the date of acquisition. See Note 11 , " Acquired Sales Contracts " for further information related to the Company's acquired sales contracts. Exploration Costs Costs to acquire permits for exploration activities are capitalized. Drilling and other costs related to locating coal deposits and evaluating the economic viability of such deposits are expensed as incurred. Prepaid Royalties Leased mineral rights are often acquired through royalty payments. When royalty payments represent prepayments recoupable against royalties owed on future revenues from the underlying coal, they are recorded as a prepaid asset, with amounts expected to be recouped within one year classified as current. When coal from these leases is sold, the royalties owed are recouped against the prepayment and charged to cost of sales. An impairment charge is recognized for prepaid royalties that are not expected to be recouped. Property, Plant and Equipment Plant and Equipment Plant and equipment are recorded at cost. Interest costs incurred during the construction period for major asset additions are capitalized. We did not capitalize any interest costs during the years ended December 31, 2015 and 2014 respectively. Expenditures that extend the useful lives of existing plant and equipment or increase the productivity of the asset are capitalized. The cost of maintenance and repairs that do not extend the useful life or increase the productivity of the asset is expensed as incurred. Preparation plants and loadouts are depreciated using the units-of-production method over the estimated recoverable reserves, subject to a minimum level of depreciation. Other plant and equipment are depreciated principally using the straight-line method over the estimated useful lives of the assets, limited by the remaining life of the mine. The useful lives of mining equipment, including longwalls, draglines and shovels, range from 5 to 32 years. The useful lives of buildings and leasehold improvements generally range from 10 to 30 years. Deferred Mine Development Costs of developing new mines or significantly expanding the capacity of existing mines are capitalized and amortized using the units-of-production method over the estimated recoverable reserves that are associated with the property being benefited. Costs may include construction permits and licenses; mine design; construction of access roads, shafts, slopes and main entries; and removing overburden to access reserves in a new pit. Additionally, deferred mine development includes the asset cost associated with asset retirement obligations. Coal Lands and Mineral Rights Rights to coal reserves may be acquired directly through governmental or private entities. A significant portion of the Company's coal reserves are controlled through leasing arrangements. Lease agreements are generally long-term in nature (original terms range from 10 to 50 years), and substantially all of the leases contain provisions that allow for automatic extension of the lease term providing certain requirements are met. The net book value of the Company's coal interests was $2.4 billion and $4.7 billion at December 31, 2015 and 2014 , respectively. Payments to acquire royalty lease agreements and lease bonus payments are capitalized as a cost of the underlying mineral reserves and depleted over the life of proven and probable reserves. Coal lease rights are depleted using the units-of-production method, and the rights are assumed to have no residual value. Future lease bonus payments total $60.0 million in 2016 . Depreciation, depletion and amortization. The depreciation, depletion and amortization related to long-lived assets is reflected in the statement of operations as a separate line item. No depreciation, depletion or amortization is included in any other operating cost categories. Impairment If facts and circumstances suggest that the carrying value of a long-lived asset or asset group may not be recoverable, the asset or asset group is reviewed for potential impairment. If this review indicates that the carrying amount of the asset will not be recoverable through projected undiscounted cash flows generated by the asset and its related asset group over its remaining life, then an impairment loss is recognized by reducing the carrying value of the asset to its fair value. The Company may, under certain circumstances, idle mining operations in response to market conditions or other factors. Because an idling is not a permanent closure, it is not considered an automatic indicator of impairment. See additional discussion in Note 5 , " Impairment Charges and Mine Closure Costs ." Goodwill In a business combination, goodwill represents the excess of the purchase price over the fair value assigned to the net tangible and identifiable intangible assets acquired. The Company tests goodwill for impairment annually as of the beginning of the fourth quarter, or when circumstances indicate a possible impairment may exist. If the results of the testing indicate that the carrying amount of a reporting unit exceeds the fair value of the reporting unit, the fair value of goodwill must be calculated. An impairment loss generally would be recognized when the carrying amount of goodwill exceeds the implied fair value of goodwill, determined by subtracting the fair value of the other assets and liabilities associated with the reporting unit from the total fair value of the reporting unit. The fair value of a reporting unit is determined using a discounted cash flow ("DCF") technique. A number of significant assumptions and estimates are involved in the application of the DCF analysis to forecast operating cash flows, including the discount rate, projections of production volumes, quality and costs to produce; projections of sales volumes by market (e.g., thermal versus metallurgical); and projections of market prices. See additional discussion in Note 6 , " Goodwill ." Deferred Financing Costs The Company capitalizes costs incurred in connection with new borrowings, the establishment or enhancement of credit facilities and the 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 interest method. The unamortized balance of deferred financing costs was $112.9 million and $89.1 million at December 31, 2015 and 2014 , respectively. Amounts classified as current were $65.6 million and $25.5 million at December 31, 2015 and 2014 , respectively. Current amounts are recorded in "Other current assets" and noncurrent amounts are recorded in "Other noncurrent assets" in the accompanying consolidated balance sheets. Revenue Recognition Revenues include sales to customers of coal produced at Company operations and coal purchased from third parties. The Company recognizes revenue at the time risk of loss passes to the customer at contracted amounts. Transportation costs are included in cost of sales and amounts billed by the Company to its customers for transportation are included in revenues. Other Operating Expense (Income), net Other operating expense (income), net in the accompanying consolidated statements of operations reflects income and expense from sources other than physical coal sales, including: bookouts, or the practice of offsetting purchase and sale contracts for shipping convenience purposes; contract settlements; liquidated damage charges related to unused terminal and port capacity; royalties earned from properties leased to third parties; income from equity investments (Note 10 ); gains and losses from divestitures and dispositions of assets (Note 3 ); and realized gains and losses on derivatives that do not qualify for hedge accounting and are not held for trading purposes (Note 12 ). Asset Retirement Obligations The Company's legal obligations associated with the retirement of long-lived assets are recognized at fair value at the time the obligations are incurred. Accretion expense is recognized through the expected settlement date of the obligation. Obligations are incurred at the time development of a mine commences for underground and surface mines or construction begins for support facilities, refuse areas and slurry ponds. The obligation's fair value is determined using a discounted cash flow technique and is based upon permit requirements and various estimates and assumptions that would be used by market participants, including estimates of disturbed acreage, reclamation costs and assumptions regarding equipment productivity. Upon initial recognition of a liability, a corresponding amount is capitalized as part of the carrying value of the related long-lived asset. The Company reviews its asset retirement obligation at least annually and makes necessary adjustments for permit changes as granted by state authorities and for revisions of estimates of the amount and timing of costs. For ongoing operations, adjustments to the liability result in an adjustment to the corresponding asset. For idle operations, adjustments to the liability are recognized as income or expense in the period the adjustment is recorded. Any difference between the recorded obligation and the actual cost of reclamation is recorded in profit or loss in the period the obligation is settled. See additional discussion in Note 16 , " Asset Retirement Obligations ." Loss Contingencies The Company accrues for cost related to contingencies when a loss is probable and the amount is reasonably determinable. Disclosure of contingencies is included in the financial statements when it is at least reasonably possible that a material loss or an additional material loss in excess of amounts already accrued may be incurred. The amount accrued represents the Company's best estimate of the loss, or, if no best estimate within a range of outcomes exists, the minimum amount in the range. Derivative Instruments The Company generally utilizes derivative instruments to manage exposures to commodity prices. Additionally, the Company may hold certain coal derivative instruments for trading purposes. Derivative financial instruments are recognized in the balance sheet at fair value. Certain coal contracts may meet the definition of a derivative instrument, but because they provide for the physical purchase or sale of coal in quantities expected to be used or sold by the Company over a reasonable period in the normal course of business, they are not recognized on the balance sheet. Certain derivative instruments are designated as the hedge instrument in a hedging relationship. In a fair value hedge, the Company hedges the risk of changes in the fair value of a firm commitment, typically a fixed-price coal sales contract. Changes in both the hedged firm commitment and the fair value of a derivative used as a hedge instrument in a fair value hedge are recorded in earnings. In a cash flow hedge, the Company hedges the risk of changes in future cash flows related to a forecasted purchase or sale. Changes in the fair value of the derivative instrument used as a hedge instrument in a cash flow hedge are recorded in other comprehensive income or loss. Amounts in other comprehensive income or loss are reclassified to earnings when the hedged transaction affects earnings and are classified in a manner consistent with the transaction being hedged. The Company formally documents the relationships between hedging instruments and the respective hedged items, as well as its risk management objectives for hedge transactions. The Company evaluates the effectiveness of its hedging relationships both at the hedge's inception and on an ongoing basis. Any ineffective portion of the change in fair value of a derivative instrument used as a hedge instrument in a fair value or cash flow hedge is recognized immediately in earnings. The ineffective portion is based on the extent to which exact offset is not achieved between the change in fair value of the hedge instrument and the cumulative change in expected future cash flows on the hedged transaction from inception of the hedge in a cash flow hedge or the change in the fair value. Ineffectiveness was insignificant for the years ended December 31, 2015, 2014 and 2013. See Note 12 , "Derivatives" for further disclosures related to the Company's derivative instruments. Fair Value Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly hypothetical 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. See Note 17 , "Fair Value Measurements" for further disclosures related to the Company's recurring fair value estimates. Income Taxes Deferred income taxes are provided for temporary differences arising from differences between the financial statement 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 that a deferred tax asset will not be realized. Management reassesses the ability to realize its deferred tax assets annually in the fourth quarter or when circumstances indicate that the ability to realize deferred tax assets has changed. In determining the need for a valuation allowance, the Company considers projected realization of tax benefits based on expected levels of future taxable income, available tax planning strategies and the reversal of temporary differences. Benefits from tax positions that are uncertain are not recognized unless the Company concludes that it is more likely than not that the position would be sustained in a dispute with taxing authorities, should the dispute be taken to the court of last resort. The Company would measure any such benefit at the largest amount of benefit that is greater than 50 percent likely of being realized upon settlement with taxing authorities. See Note 15 , "Taxes" for further disclosures about income taxes. Benefit Plans The Company has non-contributory defined benefit pension plans covering most of its salaried and hourly employees. On January 1, 2015 the Company's cash balance and excess pension plans were amended to freeze new service credits for any new or active employee. The Company also currently provides certain postretirement medical and life insurance coverage for eligible employees. The cost of providing these benefits are determined on an actuarial basis and accrued over the employee's period of active service. The Company recognizes the overfunded or underfunded status of these plans as determined on an actuarial basis on the balance sheet and the changes in the funded status are recognized in other comprehensive income. See Note 21 , " Employee Benefit Plans " for additional disclosures relating to these obligations. Stock-Based Compensation The compensation cost of all stock-based awards is determined based on the grant-date fair value of the award, and is recognized over the requisite service period. The grant-date fair value of option awards is determined using a Black-Scholes option pricing model. Compensation cost for an award with performance conditions is accrued if it is probable that the conditions will be met. See further discussion in Note 19 , " Stock-Based Compensation and Other Incentive Plans ." Accounting Standards Issued In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers. ASU 2014-09 is a comprehensive revenue recognition standard that will supersede nearly all existing revenue recognition guidance under current U.S. GAAP and replace it with a principle based approach for determining revenue recognition. ASU 2014-09 will require that companies recognize revenue based on the value of transferred goods or services as they occur in the contract. The ASU also will require 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 obtain or fulfill a contract. ASU 2014-09 is effective for interim and annual periods beginning after December 15, 2017. Early adoption is permitted only in annual reporting periods beginning after December 15, 2016, including interim periods therein. Entities will be able to transition to the standard either retrospectively or as a cumulative-effect adjustment as of the date of adoption. The Company is in the process of evaluating the impact of ASU 2014-09 on the Company’s financial statements and disclosures. 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." ASU 2014-15 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 update provides guidance to an organization's management, with principles and definitions that are intended to reduce diversity in the timing and content of disclosures that are commonly provided by organizations today in the financial statement footnotes. The amendments are effective for the Company's fiscal year and interim periods within those years beginning after November 1, 2017. Early application is permitted. The Company is in the process of evaluating the impact of ASU 2014-15 on the Company’s financial statements and disclosures. In April 2015, the Financial Accounting Standards Board ("FASB") issued the Accounting Standards Update No. 2015-03 ("ASU 2015-03"), Simplifying the Presentation of Debt Issuance Costs. ASU 2015-03 requires debt issuance costs related to recognized debt liability to be presented in the balance sheet as a direct deduction from the carrying amount of the liability, consistent with debt discounts. Amendments in the update are effective retrospectively for fiscal years and interim periods within those years, beginning after December 15, 2015, with early adoption permitted. Upon adoption of this guidance, the current financial statement classification of debt issuance costs will change from total assets to long-term debt on our Consolidated Balance Sheets. In August 2015, the FASB issued ASU 2015-15, " Interest - Imputation of Interest (Subtopic 835-30) - Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements ". On April 7, 2015, the FASB issued ASU 2015-03, Interest-Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs, which requires entities to present debt issuance costs related to a recognized debt liability as a direct deduction from the carrying amount of that debt liability. Given the absence of authoritative guidance within ASU 2015-03 for debt issuance costs related to line-of-credit arrangements, the SEC staff stated that they would not object to an entity deferring and presenting debt issuance costs as an asset and subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. ASU 2015-15 adds these SEC comments to the "S" section of the Codification. The adoption of this standard is not expected to have a material impact on the Company's consolidated financial statements. In May 2015, the FASB issued ASU No. 2015-07 “Fair Value Measurement (Topic 820), Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or its Equivalent)” . This ASU eliminates the requirement to categorize within the fair value hierarchy investments who fair values are measured at net asset value (NAV) using the practical expedient in ASC 820. Instead entities will have to disclose the fair values of such investments so that financial statement users can reconcile amounts reported in the fair value hierarchy table to the amounts reported in the balance sheet. ASU 2015-07 is effective for public business entities in fiscal years beginning after 15 December 2015 and interim periods within those years. Early adoption is permitted and guidance will be applied retrospectively. The Company is currently evaluating the impact the adoption of ASU 2015-07 on the Company’s financial statements and disclosures. In July 2015, the FASB issued Accounting Standards Update 2015-11, Simplifying the Measurement of Inventory, which requires that inventory within the scope of ASU 2015-11 be measured at the lower of cost and net realizable value. Inventory measured using last-in, first-out (LIFO) and the retail inventory method are not impacted by the new guidance. ASU 2015-11 applies to all other inventory, which includes inventory that is measured using first-in, first-out (FIFO) or average cost. An entity should measure inventory within the scope of ASU 2015-11 at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. ASU 2015-11 is effective for public business entities in fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU 2015-11 on the Company’s financial statements and disclosures. On November 20, 2015, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2015-17, Balance Sheet Classification of Deferred Taxes, requiring all deferred tax assets and liabilities, and any related valuation allowance, to be classified as noncurrent on the balance sheet. The classification change for all deferred taxes as noncurrent simplifies entities’ processes as it eliminates the need to separately identify the net current and net noncurrent deferred tax asset or liability in each jurisdiction and allocate valuation allowances. The Company is in the process of evaluating the impact of ASU 2015-07 on the Company’s financial statements and disclosures.

Divestitures

Divestitures	12 Months Ended
	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Divestitures	Divestitures During 2014, the Company entered into agreements to sell various non-core operations, including operating and idled thermal coal complexes in Kentucky and the Company's highwall manufacturing subsidiary. The Company received $46.7 million in cash and recognized a net pre-tax gain of $17.8 million from these divestitures, reflected in "other operating expense (income), net" in the Consolidated Statement of Operations. As part of a strategy to divest non-core thermal coal assets, the Company entered into a definitive agreement on June 27, 2013 to sell Canyon Fuel, to Bowie Resources, LLC. Canyon Fuel operated two longwall mining complexes and a continuous miner operation in Utah. The sale was completed on August 16, 2013, for $422.7 million in cash, including adjustments to the purchase price to finalize working capital. The following table summarizes the results of discontinued operations through the date of disposition: Year Ended December 31, 2013 Total Revenues $ 219,002 Income from discontinued operations before income taxes $ 32,167 Gain on sale 120,321 Less: income tax expense 49,092 Income from discontinued operations, including gain on sale - net of tax $ 103,396 Basic earnings per common share from discontinued operations $ 4.87 Diluted earnings per common share from discontinued operations $ 4.87

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) The following items are included in accumulated other comprehensive income (loss): Pension, Postretirement Accumulated and Other Post- Other Derivative Employment Available-for- Comprehensive Instruments Benefits Sale Securities Income (Loss) (In thousands) Balance at January 1, 2014 $ 565 $ 31,112 $ 6,015 $ 37,692 Unrealized gains 3,677 (22,516 ) (5,727 ) (24,566 ) Amounts reclassified from accumulated other comprehensive income (loss) (1,692 ) (5,736 ) (2,457 ) (9,885 ) Balance at December 31, 2014 2,550 2,860 (2,169 ) 3,241 Unrealized gains (losses) 3,903 (8,723 ) (3,333 ) (8,153 ) Amounts reclassified from accumulated other comprehensive income (loss) (6,128 ) 5,142 4,083 3,097 Balance at December 31, 2015 $ 325 $ (721 ) $ (1,419 ) $ (1,815 ) The following amounts were reclassified out of accumulated other comprehensive income (loss) during the years ended December 31, 2015 and 2014 , respectively: Details about accumulated other comprehensive income components Reclassifications Line Item in the Consolidated Statement of Operations 2015 2014 (in thousands) Derivative instruments $ 9,575 $ 2,643 Revenues (3,447 ) (951 ) Provision for (benefit from) income taxes $ 6,128 $ 1,692 Net of tax Pension, postretirement and other post-employment benefits Amortization of prior service credits $ 8,335 1 $ 11,760 Amortization of net actuarial gains (losses) (16,369 ) 1 (2,797 ) (8,034 ) 8,963 Total before tax 2,892 (3,227 ) Provision for (benefit from) income taxes $ (5,142 ) $ 5,736 Net of tax Available-for-sale securities $ (6,391 ) 2 $ 3,838 Interest and investment income 2,308 (1,381 ) Provision for (benefit from) income taxes $ (4,083 ) $ 2,457 Net of tax 1 Production-related benefits and workers' compensation costs are included in costs to produce coal. 2 The gains and losses on sales of available-for-sale-securities are determined on a specific identification basis.

Impairment Charges and Mine Clo

Impairment Charges and Mine Closure Costs	12 Months Ended
	Dec. 31, 2015
Impairment Charges and Mine Closure Costs [Abstract]
Impairment Charges and Mine Closure Costs	Impairment Charges and Mine Closure Costs The following table summarizes the amounts reflected on the line " Asset impairment and mine closure costs " in the consolidated statements of operations: Year Ended December 31, Description 2015 2014 2013 (In thousands) Coal lands and mineral rights $ 2,210,488 $ — $ 79,094 Plant and equipment 199,107 1,512 36,296 Deferred development 159,474 — 13,451 Prepaid royalties 41,990 15,356 1,104 Equity investments 21,325 — 28,947 Notes receivable — — 49,203 Inventories 66 — 12,765 Other (4,147 ) 7,245 19 Total $ 2,628,303 $ 24,113 $ 220,879 2015 Impairment Charges In 2015, as a result of the continued deterioration in thermal and metallurgical coal markets and projections for a muted pricing recovery, certain of the Company’s mine complexes have incurred and are expected to continue to incur operating losses. The Company determined that the further weakening of the pricing environment in the last half of the year and the projected operating losses represent indicators of impairment with respect to certain of its long-lived assets or assets groups. Using current pricing expectations which reflect marketplace participant assumptions, life of mine cash flows were used to determine if the undiscounted cash flows exceed the current asset values for certain operating complexes in the Company’s Appalachia segment. For multiple operating complexes, the undiscounted cash flows did not exceed the carrying value of the long-lived assets. Discounted cash flows were utilized to reduce the carrying value of those assets to fair value. The discount rate used reflects the current financial difficulties present in the commodities sector in general and coal mining specifically; the perceived risk of financing coal mining in light of industry defaults; and the lack of an active market for buying or selling coal mining assets. Additionally, the Company determined that the current market conditions represent an indicator of impairment for certain undeveloped coal properties that were acquired in times of significantly higher coal prices. Current prices and the significant capital outlay that would be required to develop these reserves indicate that the carrying value is not recoverable. As a result the Company recorded a $2.6 billion asset impairment charge in the last two quarters of 2015 of which $2.1 billion was recorded during the third quarter and the remaining $0.5 billion was recorded in the fourth quarter. Of the total charge. $2.2 billion was recorded to the Company's Appalachia segment, with the remaining $0.4 billion to the Company's Other operating segment. There is no fair value remaining related to the impaired assets. During the second quarter of 2015, the Company recorded $19.1 million to "Asset impairment and mine closure costs" in the Consolidated Statements of Operations. An impairment charge of $12.2 million relates to the portion of an advance royalty balance on a reserve base mined at the Company's Mountain Laurel, Spruce and Briar Branch operations that will not be recouped based on latest estimates of sales volume and pricing through the March 2017 recoupment period. Additionally, the company recorded a $5.6 million impairment charge related to the closure of a higher-cost mining complex serving the metallurgical coal markets. 2014 Impairment Charges During the Company's annual budgeting process for 2015 (performed in the fall of 2014), a review of forecasted revenues indicated that the remaining balance of advance royalty payments made on a reserve base supplying the Company's Mountain Laurel, Spruce Mine and Briar Branch operations would not be recoupable against future royalties payments. Under the lease, any unrecouped advance payment balance at March 31, 2017 will be forfeited by the Company. Based on estimates of sales volumes and pricing through the end of the recoupment period, an impairment charge was recorded during the fourth quarter of 2014 for $15.4 million of the remaining $48.0 million balance that would not be recouped. In response to weak metallurgical coal markets the Company idled a higher-cost mining complex in the third quarter of 2014 in order to concentrate on metallurgical coal production from its lowest-cost and highest-margin operations. Closure charges of $5.1 million were recognized during the third quarter of 2014 relating to the idling. 2013 Impairment Charges As a result of the weak thermal coal markets in Appalachia, the Company assessed in the third quarter of 2013 whether the carrying values of certain assets were recoverable through future cash flows. The Company determined that the carrying amounts of certain assets associated with the Hazard mining complex in Kentucky and the Company's ADDCAR subsidiary, which manufactures and sells its patented highwall mining system, could not be recovered through future cash flows expected to be generated from use of the assets and their ultimate disposal. The assets' fair values were determined based on projections of cash flows to be generated from use of the assets and their ultimate disposal including estimates relating to market demand, coal prices, production costs and mine plans, and recovery value of the assets. An impairment charge of $142.8 million was recognized to adjust the carrying value of the assets to their fair value of $71.3 million . During 2013, the Company also recognized other-than-temporary impairment charges related to equity method investments. See further discussion in Note 10 , "Equity Method Investments and Membership Interests in Joint Ventures." Due to the unobservable inputs within the modeling used to determine fair market value within the Company's asset impairment process, the fair value would be considered level 3 within the fair value hierarchy.

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill Changes in the carrying value of goodwill for the three years ended December 31, 2015 are as follows: (In thousands) Balance at January 1, 2013 $ 265,423 Impairment (265,423 ) Balance at December 31, 2013 $ — The Company performed its annual impairment testing as of October 1, 2013 on its two remaining Appalachia reporting units with goodwill balances, the Leer mining complex and an undeveloped property adjacent to it. The fair value of these two reporting units are sensitive to the volatility in the demand for and pricing of metallurgical coal, and continuing weakness in the metallurgical coal markets resulted in a reassessment of key marketing and operating assumptions during the Company's annual budgeting process. As a result, the book values of the reporting units exceeded their fair values after the first step of the goodwill impairment tests. It was also determined that the goodwill had no fair value, and the Company recognized an impairment loss for the remaining reporting units totaling $265.4 million .

Losses from disposed operations

Losses from disposed operations resulting from Patriot Coal Bankruptcy	12 Months Ended
	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Losses from disposed operations resulting from Patriot Coal Bankruptcy	Losses from disposed operations resulting from Patriot Coal bankruptcy On December 31, 2005, Arch entered into a purchase and sale agreement with Magnum to sell certain operations. On July 23, 2008, Patriot acquired Magnum. On May 12, 2015, Patriot and certain of its wholly owned subsidiaries (“Debtors”), including Magnum, filed voluntary petitions for reorganization under Chapter 11 of the U.S. Code in the U.S. Bankruptcy Court for the Eastern District of Virginia. Subsequently, on October 28, 2015, Patriot’s Plan of Reorganization was approved, including an authorization to reject their collective bargaining agreements and modify certain union-related retiree benefits. As a result of the Plan of Reorganization, the Company became statutorily responsible for retiree medical benefits pursuant to Section 9711 of the Coal Industry Retiree Health Benefit Act of 1992 for certain retirees of Magnum who retired prior to October 1, 1994. In addition, the Company has provided surety bonds to Patriot related to permits that were sold to an affiliate of Virginia Conservation Legacy Fund, Inc. (“VCLF”). Should VCLF not perform required reclamation, the Company would incur losses under the bonds and related indemnity agreements. The Company recognized $116.3 million in losses in 2015 related to the previously disposed operations as a result of the Patriot Coal bankruptcy. An original charge of $149.3 million was recorded in the third quarter of 2015 based on our best estimate at the time. This was subsequently reduced by $33.0 million in the fourth quarter due to revised census data and changes in underlying assumptions related to the retiree medical benefits.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2015
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consist of the following: December 31, 2015 2014 (In thousands) Coal $ 85,043 $ 71,901 Repair parts and supplies 111,677 118,352 $ 196,720 $ 190,253 The repair parts and supplies are stated net of an allowance for slow-moving and obsolete inventories of $6.0 million at December 31, 2015 and $6.6 million at December 31, 2014 .

Investments in Available-for-Sa

Investments in Available-for-Sale Securities	12 Months Ended
	Dec. 31, 2015
Available-for-sale Securities [Abstract]
Investments in Available-for-Sale Securities	Investments in Available-for-Sale Securities The Company has invested primarily in highly liquid investment-grade corporate bonds. These investments are held in the custody of a major financial institution. These securities, along with the Company's investments in marketable equity securities, are classified as available-for-sale securities and, accordingly, the unrealized gains and losses are recorded through other comprehensive income. The Company's investments in available-for-sale marketable securities are as follows: December 31, 2015 Balance Sheet Gross Gross Classification Unrealized Unrealized Fair Short-Term Other Cost Basis Gains Losses Value Investments Assets (In thousands) Available-for-sale: U.S. government and agency securities $ 10,007 $ — $ (12 ) $ 9,995 $ 9,995 Corporate notes and bonds 190,496 — (299 ) 190,197 190,197 — Equity securities 3,938 668 (2,888 ) 1,718 — 1,718 Total Investments $ 204,441 $ 668 $ (3,199 ) $ 201,910 $ 200,192 $ 1,718 December 31, 2014 Balance Sheet Gross Gross Classification Unrealized Unrealized Fair Short-Term Other Cost Basis Gains Losses Value Investments Assets (In thousands) Available-for-sale: Corporate notes and bonds $ 253,590 $ — $ (4,636 ) $ 248,954 $ 248,954 $ — Equity securities 3,910 4,125 (2,890 ) 5,145 — 5,145 Total Investments $ 257,500 $ 4,125 $ (7,526 ) $ 254,099 $ 248,954 $ 5,145 The aggregate fair value of investments with unrealized losses that had been owned for less than a year was $184.6 million and $163.0 million at December 31, 2015 and 2014 , respectively. The aggregate fair value of investments with unrealized losses that have been owned for over a year was $15.8 million and $86.1 million at December 31, 2015 and 2014 , respectively. The debt securities outstanding at December 31, 2015 have maturity dates ranging from the first quarter of 2016 through the second quarter of 2017 . The Company classifies its investments as current based on the nature of the investments and their availability to provide cash for use in current operations, if needed.

Equity Method Investments and M

Equity Method Investments and Membership Interests in Joint Ventures	12 Months Ended
	Dec. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments and Membership Interests in Joint Ventures	Equity Method Investments and Membership Interests in Joint Ventures The Company accounts for its investments and membership interests in joint ventures under the equity method of accounting if the Company has the ability to exercise significant influence, but not control, over the entity. Equity method investments are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the investments may not be recoverable. Certain of the Company's investments are in development stage companies whose success depends on factors including the receipt of permits and other regulatory environmental issues, the ability of the investee companies to raise additional funds in financial markets that can be volatile and other key business factors, any of which may impact the Company's ability to recover its investment. Below are the equity method investments reflected in the consolidated balance sheets: Investee Knight Hawk DTA Millennium Tongue River DKRW Tenaska Other Total Balance at January 1, 2013 $ 149,063 $ 15,462 $ 32,214 $ 14,697 $ 15,515 $ 15,264 $ — $ 242,215 Advances to (distributions from) affiliates, net (13,536 ) 3,644 6,476 4,004 — — 200 788 Equity in comprehensive income (loss) 17,279 (4,969 ) (2,796 ) (282 ) (1,832 ) — — 7,400 Impairment of equity investment — — — — (13,683 ) (15,264 ) — (28,947 ) Balance at December 31, 2013 152,806 14,137 35,894 18,419 — — 200 221,456 Advances to (distributions from) affiliates, net (12,603 ) 3,774 6,742 2,541 — — 3,600 4,054 Equity in comprehensive income (loss) 18,274 (4,173 ) (2,413 ) (220 ) — — (1,136 ) 10,332 Balance at December 31, 2014 158,477 13,738 40,223 20,740 — — 2,664 235,842 Advances to (distributions from) affiliates, net (29,862 ) 3,207 7,052 913 — — 330 (18,360 ) Equity in comprehensive income (loss) 22,977 (3,706 ) (9,686 ) (328 ) — — (1,278 ) 7,979 Impairment of equity investment — — — (21,325 ) — — — (21,325 ) Sale of equity investment — — — — — — (2,259 ) $ (2,259 ) Balance at December 31, 2015 $ 151,592 $ 13,239 $ 37,589 $ — $ — $ — $ (543 ) $ 201,877 The Company holds a 49% equity interest in Knight Hawk Holdings, LLC ("Knight Hawk"), a coal producer in the Illinois Basin. The Company holds a general partnership interest of 21.875% in Dominion Terminal Associates ("DTA"), which is accounted for under the equity method. DTA operates a ground storage-to-vessel coal transloading facility in Newport News, Virginia for use by the partners. Under the terms of a throughput and handling agreement with DTA, each partner is charged its share of cash operating and debt-service costs in exchange for the right to use the facility's loading capacity and is required to make periodic cash advances to DTA to fund such costs. The Company holds a 38% ownership interest in Millennium Bulk Terminals-Longview, LLC ("Millennium"), the owner of a brownfield bulk commodity terminal on the Columbia River near Longview, Washington. Additional future purchase consideration is due upon the completion of certain project milestones. Millennium continues to work on obtaining the required approvals and necessary permits to complete dredging and other upgrades to ship coal, alumina and cementitious material from the terminal. The Company will control 38% of the terminal's throughput and storage capacity, in order to facilitate export shipments of coal off the west coast of the United States. The Company holds a 35% membership interest in the Tongue River Holding Company, LLC ("Tongue River") joint venture. Tongue River will develop and construct a railway line near Miles City, Montana and the Company's Otter Creek reserves. The Company has the right, upon the receipt of permits and approval for construction or under other prescribed circumstances, to require the other investors to purchase all of the Company's units in the venture at an amount equal to the capital contributions made by the Company at that time, less any distributions received. During the third quarter of 2015, the Company recorded an impairment charge of $21.3 million representing the entire value of the Company's investment in the project; the impairment charge is included on the line "Asset impairment and mine closure costs." The Company holds a 24% equity interest in DKRW Advanced Fuels LLC ("DKRW"), who had entered into an Engineering, Procurement and Construction Agreement with a Chinese company to construct and commission the Medicine Bow coal-to-liquids facility. However, as the project did not progress to the next stage of development, the Company recorded an other-than-temporary impairment charge of $57.7 million in the third quarter of 2013, representing the Company's equity investment of $13.7 million and an outstanding $44.0 million loan receivable balance. The impairment charges are included on the line "Asset impairment and mine closure costs" in the consolidated statement of operations. During the second quarter of 2013, Tenaska Trailblazer Partners, LLC ("Tenaska") announced that it was discontinuing its development plans for the Trailblazer Energy Center in Texas. As a result, the Company recorded a $20.5 million impairment charge, which consisted of its 35% equity investment of $15.3 million and a $5.2 million receivable balance related to advances for development work. The impairment charges are included on the line "Asset impairment and mine closure costs" in the consolidated statement of operations. The Company may be required to make future contingent payments of up to $58.5 million related to development financing for certain of its equity investees. The Company’s obligation to make these payments, as well as the timing of any payments required, is contingent upon the achievement of project development milestones.

Acquired Sales Contracts

Acquired Sales Contracts	12 Months Ended
	Dec. 31, 2015
Acquired Sales Contracts [Abstract]
Acquired Sales Contracts	Acquired Sales Contracts The acquired sales contracts reflected in the consolidated balance sheets are as follows: December 31, 2015 December 31, 2014 Assets Liabilities Net Total Assets Liabilities Net Total (In thousands) (In thousands) Acquired fair value $ 131,299 $ 166,697 $ 131,299 $ 166,697 Accumulated amortization (130,839 ) (151,354 ) (130,363 ) (134,988 ) Total $ 460 $ 15,343 $ (14,883 ) $ 936 $ 31,709 $ (30,773 ) Balance Sheet classification: Other current $ 460 $ 3,852 $ 462 $ 12,453 Other noncurrent $ — $ 11,491 $ 474 $ 19,256 The Company anticipates amortization of acquired sales contracts, based upon expected shipments in the next five years, to be income of approximately $3.3 million in 2016 , $3.7 million in 2017 , $3.7 million in 2018 , $3.7 million in 2019 and $0.3 million in 2020 .

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives Diesel fuel price risk management The Company is exposed to price risk with respect to diesel fuel purchased for use in its operations. The Company anticipates purchasing approximately 50 to 58 million gallons of diesel fuel for use in its operations during 2016 . To protect the Company’s cash flows from increases in the price of diesel fuel for its operations, the Company may use forward physical diesel purchase contracts and purchase out-of-the-money heating oil call options to protect against substantial increases in pricing. At December 31, 2015 , the Company had heating oil call options for approximately 56 million gallons at an average strike price of $1.98 . Coal risk management positions The Company may sell or purchase forward contracts, swaps and options in the over-the-counter coal market in order to manage its exposure to coal prices. The Company has exposure to the risk of fluctuating coal prices related to forecasted sales or purchases of coal or to the risk of changes in the fair value of a fixed price physical sales contract. Certain derivative contracts may be designated as hedges of these risks. At December 31, 2015 , the Company held derivatives for risk management purposes that are expected to settle in the following years: (Tons in thousands) 2016 2017 Total Coal sales 480 — 480 Coal purchases 255 — 255 Coal trading positions The Company may sell or purchase forward contracts, swaps and options in the over-the-counter coal market for trading purposes. The Company is exposed to the risk of changes in coal prices on the value of its coal trading portfolio. The unrecognized gains of $5.8 million in the trading portfolio are expected to be realized in 2016 . Tabular derivatives disclosures The Company has master netting agreements with all of its counterparties which allow for the settlement of contracts in an asset position with contracts in a liability position in the event of default or termination. Such netting arrangements reduce the Company’s credit exposure related to these counterparties. For classification purposes, the Company records the net fair value of all the positions with a given counterparty as a net asset or liability in the consolidated balance sheets. The amounts shown in the table below represent the fair value position of individual contracts, and not the net position presented in the accompanying consolidated balance sheets. The fair value and location of derivatives reflected in the accompanying consolidated balance sheets are as follows: December 31, 2015 December 31, 2014 Fair Value of Derivatives Asset Liability Asset Liability (In thousands) Derivative Derivative Derivative Derivative Derivatives Designated as Hedging Instruments Coal $ 4 $ (20 ) $ 6,535 $ (2,492 ) Derivatives Not Designated as Hedging Instruments Heating oil -- diesel purchases 1,017 — 300 — Coal held for trading purposes, exchange traded swaps and futures 110,653 (104,814 ) 96,898 (93,272 ) Coal -- risk management 3,912 (1,947 ) 8,510 (3,688 ) Natural gas 494 (247 ) — — Total 116,076 (107,008 ) 105,708 (96,960 ) Total derivatives 116,080 (107,028 ) 112,243 (99,452 ) Effect of counterparty netting (107,028 ) 107,028 (98,686 ) 98,686 Net derivatives as classified in the balance sheets $ 9,052 $ — $ 9,052 $ 13,557 $ (766 ) $ 12,791 December 31, 2015 2014 Net derivatives as reflected on the balance sheets Heating oil Other current assets $ 1,017 $ 300 Coal Coal derivative assets 8,035 13,257 Accrued expenses and other current liabilities — (766 ) $ 9,052 $ 12,791 The Company had a current asset for the right to reclaim cash collateral of $1.7 million and a current liability for the obligation to return cash collateral of $2.4 million at December 31, 2015 and 2014 , respectively. These amounts are not included with the derivatives presented in the table above and are included in "other current assets" and “other current liabilities”, respectively, in the accompanying consolidated balance sheets. The effects of derivatives on measures of financial performance are as follows: Derivatives used in Cash Flow Hedging Relationships (in thousands) For the year ended December 31, Gain (Loss) Recognized in Other Comprehensive Income (Effective Portion) Gains (Losses) Reclassified from Other Comprehensive Income into Income 2015 2014 2013 2015 2014 2013 Coal sales (1) $ 12,816 $ 10,842 (338 ) $ 18,635 $ 5,336 $ 3,664 Coal purchases (2) (6,718 ) (5,097 ) 526 (9,060 ) (2,693 ) (683 ) $ 6,098 $ 5,745 $ 188 $ 9,575 $ 2,643 $ 2,981 No ineffectiveness or amounts excluded from effectiveness testing relating to the Company’s cash flow hedging relationships were recognized in the results of operations in the years ended December 31, 2015 , 2014 and 2013 . Derivatives Not Designated as Hedging Instruments (in thousands) For the year ended December 31, Gain (Loss) Recognized 2015 2014 2013 Coal — unrealized (3) $ (3,883 ) $ 430 $ (12,700 ) Coal — realized (4) $ 3,236 $ 5,956 $ 32,534 Heating oil — diesel purchases (4) $ (8,294 ) $ (7,848 ) $ (9,791 ) Heating oil — fuel surcharges (4) $ — $ (405 ) $ (947 ) Natural gas $ 878 $ — $ — Foreign currency $ (887 ) $ — $ — Location in statement of operations: (1) — Revenues (2) — Cost of sales (3) — Change in fair value of coal derivatives and coal trading activities, net (4) — Other operating income, net The Company recognized net unrealized and realized gains of $5.7 million , $3.2 million , and $4.9 million during the years ended December 31, 2015 , 2014 and 2013 , respectively, related to its trading portfolio, which are included in the caption “Change in fair value of coal derivatives and coal trading activities, net” in the accompanying consolidated statements of operations, and are not included in the previous tables reflecting the effects of derivatives on measures of financial performance. Based on fair values at December 31, 2015 , losses on derivative contracts designated as hedge instruments in cash flow hedges expected to be reclassified from other comprehensive income into earnings during the next twelve months are immaterial.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2015
Accrued Expenses and Other Current Liabilities [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following: December 31, 2015 2014 (In thousands) Payroll and employee benefits $ 58,423 $ 73,362 Taxes other than income taxes 104,755 114,598 Interest 119,785 30,384 Acquired sales contracts 3,852 12,453 Workers’ compensation 16,875 16,714 Asset retirement obligations 13,795 19,222 Other 11,965 35,663 $ 329,450 $ 302,396 The increase in the accrued interest balance is due to the Company exercising the 30 -day grace period under its indenture agreements with holders of its 9.875% Senior Notes due 2019, the 7.00% Senior Notes due 2019 and the 7.25% Senior Notes due 2021 on December 15, 2015. This extended the time period the Company had to make the approximately $90 million interest payment due December 15, 2015 without triggering an event of default under the indentures. Subsequently, on January 11, 2016 (the "Petition Date"), the Company and substantially all of its wholly owned domestic subsidiaries filed voluntary petitions for reorganization under Chapter 11 of Title 11 of the U.S. Code in the United States Bankruptcy Court for the Eastern District of Missouri. See additional details in Note 26, "Subsequent Events."

Debt and Financing Arrangements

Debt and Financing Arrangements	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Debt and Financing Arrangements	Debt and Financing Arrangements December 31, 2015 2014 (In thousands) Term loan due 2018 ($1.9 billion and $1.93 billion face value, respectively) $ 1,875,429 $ 1,890,846 7.00% senior notes due 2019 at par 1,000,000 1,000,000 8.00% senior secured notes due 2019 at par 350,000 350,000 9.875% senior notes ($375.0 million face value) due 2019 365,600 363,493 7.25% senior notes due 2020 at par 500,000 500,000 7.25% senior notes due 2021 at par 1,000,000 1,000,000 Other 47,134 56,031 5,138,163 5,160,370 Less current maturities of debt 5,107,210 36,885 Long-term debt $ 30,953 $ 5,123,485 Acceleration of Debt Obligations; Automatic Stay The filing of the Bankruptcy Petitions constituted an event of default that accelerated the Company's obligations under the documents governing each of its 7.00% senior notes due 2019, 9.875% senior notes due 2019, 8.00% senior secured second lien notes due 2019, 7.25% senior notes due 2020, 7.25% senior notes due 2021 (together, the “senior notes”) and senior secured first lien term loan due 2018. Immediately after filing the Bankruptcy Petitions, the Company began notifying all known current or potential creditors of the Debtors of the bankruptcy filings. Pursuant to Section 362 of the Bankruptcy Code, the filing of the Bankruptcy Petitions automatically stayed most actions against the Debtors, including actions to collect indebtedness incurred prior to the Petition Date or to exercise control over the Debtors’ property. Subject to certain exceptions under the Bankruptcy Code, the filing of the Debtors’ Chapter 11 Cases also automatically stayed the continuation of most legal proceedings, including the third party litigation matters described under Item 3, “Legal Proceedings,” or the filing of other actions against or on behalf of the Debtors or their property to recover on, collect or secure a claim arising prior to the Petition Date or to exercise control over property of the Debtors’ bankruptcy estates, unless and until the Court modifies or lifts the automatic stay as to any such claim. Notwithstanding the general application of the automatic stay described above, governmental authorities may determine to continue actions brought under their police and regulatory powers Credit Facilities As of September 30, 2015, availability under the Company's revolver was subject to limits on secured debt in its senior note indentures. At September 30, 2015, the limit under the most restrictive indenture did not provide meaningful availability under the revolver and, as a result, on November 6, 2015 the Company delivered an irrevocable 5 day notice to the administrative agent to voluntarily terminate all commitments thereunder, which terminated on November 11, 2015. The Company had no borrowings outstanding under the revolving credit facility at September 30, 2015 and had not been using it as a source of liquidity in the recent past. The Company is also party to an accounts receivable securitization program under which eligible trade receivables are sold, without recourse, to a multi‑seller, asset‑backed commercial paper conduit. The entity through which these receivables are sold is consolidated into the Company's financial statements. The Company may borrow and draw letters of credit against the facility, and pays facility fees, program fees and letter of credit fees (based on amounts of outstanding letters of credit). The total aggregate borrowings and letters of credit are limited by eligible accounts receivable, as defined under the terms of the credit facility agreement. The credit agreement expires on December 8, 2017 . At December 31, 2015 , the Company had no available borrowing capacity under its lines of credit. Term Loan On May 16, 2012, the Company borrowed $1.4 billion under a secured term loan facility, issued at a 1% discount. The proceeds from the term loan were used to retire all outstanding borrowings under the revolving credit facility and the outstanding $450.0 million principal amount of 6.75% Senior Notes due 2013 issued by Arch Western Finance, LLC, the Company’s indirect subsidiary. On November 21, 2012, the Company borrowed an incremental $250.0 million on the term loan facility at a 1% discount at the same rate as the initial borrowing. On December 17, 2013 the credit facility amendment increased the maximum amount of term loans allowed under the facility, and the Company borrowed an incremental $300.0 million aggregate principal amount at 98% of the face amount. The term loan contains no financial maintenance covenants, is prepayable, and is secured by substantially all of the Company's assets. Quarterly principal payments of $3.5 million began in September 2012, increased to $4.125 million per quarter as a result of the incremental borrowing in November, 2012, and increased further to $4.875 million with the December 17, 2013 borrowing. A balloon payment of $1.8 billion is due in May, 2018. Interest is payable at a rate that is equal to a base of the greater of a LIBOR-based rate and 1.25% , plus 500 basis points. 2019 9.875% Notes On November 21, 2012, the Company issued $375.0 million aggregate principal amount of 9.875% senior unsecured notes due 2019 (the “2019 9.875% Notes”) at an issue price of 95.934% of the face amount. Interest is payable on the 2019 9.875% Notes annually on June 15 and December 15. The Company may redeem some or all of the notes at prices that are reflected as a percentage of the principal amount, as follows: 104.938% commencing December 15, 2016; 102.469% commencing December 15, 2017; and 100% on or after December 15, 2018. The unsecured senior notes are guaranteed by substantially all of the Company's subsidiaries, except for Arch Receivable Company, LLC, which is the conduit for the accounts receivable securitization program, and the Company's subsidiaries outside the U.S. 2019 Secured Notes On December 17, 2013, the Company issued $350.0 million aggregate principal amount of 8.00% senior secured second lien notes due 2019 (the “2019 Secured Notes”) at par. The 2019 Secured Notes are secured by the same assets that secure indebtedness under the senior secured term loan, but on a second priority basis, subject to certain exceptions and permitted liens. Interest is payable on the 2019 Secured Notes on January 15 and July 15 of each year. The Company may redeem some or all of the notes at prices that are reflected as a percentage of the principal amount, as follows: 104.0% commencing January 15, 2016, 102.0% commencing January 15, 2017, and 100% on or after January 15, 2018. 2020 Notes The Company has outstanding $500.0 million in aggregate principal amount of 7.25% senior unsecured notes due in 2020 (“2020 Notes”) at par. Interest is payable on the 2020 Notes on April 1 and October 1 of each year . The Company may redeem some or all of the 2020 Notes during the respective 12 month periods at prices that are reflected as a percentage of the principal amount, as follows: 103.625% commencing October 1, 2015; 102.417% commencing October 1, 2016; 101.208% commencing October 1, 2017; and 100% on or after October 1, 2018. 2019 7% Notes and 2021 Notes The Company has outstanding $1.0 billion of 7.00% unsecured senior notes due 2019 (“2019 7% Notes”) and $1.0 billion of 7.25% unsecured senior notes due 2021 (“2021 Notes”). Interest is payable on the 2019 7% Notes and 2021 Notes on June 15 and December 15 of each year. The Company may redeem some or all of the 2019 7% Notes at prices that are reflected as a percentage of the principal amount, as follows: 103.5% commencing June 15, 2015; 101.75% commencing June 15, 2016; and 100% on or after June 15, 2017. The Company may redeem some or all of the 2021 Notes at prices that are reflected as a percentage of the principal amount, as follows: 103.625% commencing June 15, 2016; 102.417% commencing June 15, 2017; 101.208% commencing June 15, 2018 and 100% on or after June 15, 2019. In each case, accrued and unpaid interest at the redemption date is due upon redemption. Other Debt Retirements On December 17, 2013, the Company retired the outstanding $600 million in aggregate principal amount of 8.75% senior unsecured notes due 2016 (“2016 Notes”) for $628.7 million with the proceeds from the incremental term loan and the 2019 Secured Notes. The Company recorded a $41.0 million loss related to this transaction which is reflected in the line " Net loss resulting from early retirement of debt and debt restructuring " in the Consolidated Statements of Operations. Debt Maturities The contractual maturities of debt as of December 31, 2015 are as follows, although $5.1 billion is classified as current due to the default caused by the Company's bankruptcy filing. Year 2016 $ 35,674 2017 30,484 2018 1,858,567 2019 1,731,317 2020 501,642 Thereafter 1,000,574 $ 5,158,258 Debt Covenants Terms of the Company's credit facilities and leases contain covenants that limit the ability of the Company to, among other things, acquire, dispose, merge or consolidate assets; incur additional debt; pay dividends and make distributions or repurchase stock; make investments; create liens; issue and sell capital stock of subsidiaries; enter into restrictions affecting the ability of restricted subsidiaries to make distributions, loans or advances to the Company; engage in transactions with affiliates and enter into sale and leaseback transactions. Failure by the Company to comply with such covenants could result in an event of default, which, if not cured or waived, could have a material adverse effect on the Company. Financing Costs The Company did not incur any financing costs in 2015 and paid financing costs of $4.5 million and $20.5 million in conjunction with its financing activities during the years ended December 31, 2014 and 2013 , respectively. During the year ended December 31, 2015 , the Company wrote off $3.7 million of deferred financing costs related to the termination of the revolver facility. Additionally, the company incurred $24.2 million of legal fees and financial advisory fees associated with debt restructuring activities in 2015. All amounts have been reflected in the line, " Net loss resulting from early retirement and refinancing of debt " in the Consolidated Statement of Operations.

Taxes

Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Taxes	Taxes The Company is subject to U.S. federal income tax as well as income tax in multiple state jurisdictions. The tax years 2002 through 2015 remain open to examination for U.S. federal income tax matters and 1998 through 2015 remain open to examination for various state income tax matters. Significant components of the provision for (benefit from) income taxes are as follows: Year Ended December 31 2015 2014 2013 (In thousands) Current: Federal $ — $ — $ — State 3 25 (647 ) Total current 3 25 (647 ) Deferred: Federal (329,393 ) 18,535 (318,956 ) State (43,990 ) 7,074 (15,895 ) Total deferred (373,383 ) 25,609 (334,851 ) $ (373,380 ) $ 25,634 $ (335,498 ) A reconciliation of the statutory federal income tax provision (benefit) at the statutory rate to the actual provision for (benefit from) income taxes follows: Year Ended December 31 2015 2014 2013 (In thousands) Income tax provision (benefit) at statutory rate $ (1,150,283 ) $ (186,452 ) $ (378,463 ) Percentage depletion allowance (19,035 ) (12,692 ) (15,796 ) Goodwill — — 70,301 State taxes, net of effect of federal taxes (76,445 ) (3,903 ) (25,265 ) Change in valuation allowance 865,146 226,929 8,659 Other, net 7,237 1,752 5,066 $ (373,380 ) $ 25,634 $ (335,498 ) In 2015, 2014 and 2013, compensatory stock options and other equity based compensation awards were exercised resulting in a tax expense of $6.7 million , $1.6 million and $1.5 million , respectively. The tax benefit will be recorded in paid-in capital at such point in time when a cash tax benefit is recognized. Significant components of the Company's deferred tax assets and liabilities that result from carryforwards and temporary differences between the financial statement basis and tax basis of assets and liabilities are summarized as follows: December 31, 2015 2014 (In thousands) Deferred tax assets: Net operating loss carryforwards $ 1,086,332 $ 871,848 Alternative minimum tax credit carryforwards 120,994 127,169 Reclamation and mine closure 121,276 114,430 Goodwill 38,671 50,072 Workers' compensation 42,835 38,924 Share based compensation 22,612 30,283 Acquired sales contracts 17,466 26,833 Retiree benefit plans 16,996 22,913 Contract obligations — 15,693 Advance royalties 18,751 — Losses from disposed operations resulting from Patriot Coal bankruptcy 39,287 — Other, primarily accrued liabilities 45,303 64,503 Gross deferred tax assets 1,570,523 1,362,668 Valuation allowance (1,135,399 ) (270,251 ) Total deferred tax assets 435,124 1,092,417 Deferred tax liabilities: Plant and equipment 389,169 1,354,396 Deferred development 41,047 95,129 Investment in tax partnerships — 7,377 Other 4,706 5,533 Total deferred tax liabilities 434,922 1,462,435 Net deferred (asset) liability (202 ) 370,018 The Company has federal net operating loss carryforwards for regular income tax purposes of $3.0 billion at December 31, 2015 that will expire between 2022 and 2035 . The Company has an alternative minimum tax credit carryforward of $121.0 million at December 31, 2015 , which has no expiration date and can be used to offset future regular tax in excess of the alternative minimum tax. The Company recorded increases in its valuation allowance against its deferred tax assets of $865.1 million , $226.9 million and $8.7 million in 2015, 2014 and 2013, respectively. In 2015 and 2014, the Company determined that it would not realize the all of the benefit from federal and state net operating losses, based on projections of reversing timing differences in the future. Adjustments in 2013 relate to certain state and foreign net operating loss benefits. A reconciliation of the beginning and ending amounts of gross unrecognized tax benefits follows: (In thousands) Balance at January 1, 2013 $ 31,150 Additions based on tax positions related to the current year 1,199 Additions for tax positions of prior years 688 Reductions as a result of lapses in the statute of limitations (1,248 ) Balance at December 31, 2013 31,789 Additions based on tax positions related to the current year 2,920 Balance at December 31, 2014 34,709 Additions for tax positions of the current year 4,168 Balance at December 31, 2015 $ 38,877 If recognized, the entire amount of the gross unrecognized tax benefits at December 31, 2015 would affect the effective tax rate. The Company recognizes interest and penalties related to unrecognized tax benefits in income tax expense. The Company had accrued interest and penalties of $1.7 million and $1.5 million at December 31, 2015 and 2014 , respectively. In the next 12 months, no gross unrecognized tax benefits are expected to be reduced due to the expiration of the statute of limitations.

Asset Retirement Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2015
Asset Retirement Obligation [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations The Company's asset retirement obligations arise from the Federal Surface Mining Control and Reclamation Act of 1977 and similar state statutes, which require that mine property be restored in accordance with specified standards and an approved reclamation plan. The required reclamation activities to be performed are outlined in the Company's mining permits. These activities include reclaiming the pit and support acreage at surface mines, sealing portals at underground mines, and reclaiming refuse areas and slurry ponds. The following table describes the changes to the Company's asset retirement obligation liability: Year Ended December 31, 2015 2014 (In thousands) Balance at January 1 (including current portion) $ 418,118 $ 427,653 Accretion expense 33,680 32,909 Obligations of divested operations (334 ) (30,684 ) Adjustments to the liability from changes in estimates (28,570 ) 627 Liabilities settled (12,440 ) (12,387 ) Balance at December 31 $ 410,454 $ 418,118 Current portion included in accrued expenses (13,795 ) (19,222 ) Noncurrent liability $ 396,659 $ 398,896 As of December 31, 2015 , the Company had $155.3 million in surety bonds outstanding, $485.5 million in self-bonding, and $11.2 million in letters of credit to secure reclamation bonding obligations.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The hierarchy of fair value measurements assigns a level to fair value measurements based on the inputs used in the respective valuation techniques. The levels of the hierarchy, as defined below, give the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. · Level 1 is defined as observable inputs such as quoted prices in active markets for identical assets. Level 1 assets include available-for-sale equity securities, U.S. Treasury securities, and coal swaps and futures that are submitted for clearing on the New York Mercantile Exchange. · Level 2 is 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. The Company’s level 2 assets and liabilities include U.S. government agency securities and coal commodity contracts with fair values derived from quoted prices in over-the-counter markets or from prices received from direct broker quotes. · Level 3 is defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. These include the Company’s commodity option contracts (coal and heating oil) valued using modeling techniques, such as Black-Scholes, that require the use of inputs, particularly volatility, that are rarely observable. Changes in the unobservable inputs would not have had a significant impact on the reported Level 3 fair values at December 31, 2015 and 2014 . The table below sets forth, by level, the Company’s financial assets and liabilities that are recorded at fair value in the accompanying consolidated balance sheet: Fair Value at December 31, 2015 Total Level 1 Level 2 Level 3 (In thousands) Assets: Investments in marketable securities $ 201,910 $ 11,713 $ 190,197 $ — Derivatives 9,052 5,597 1,023 2,432 Total assets $ 210,962 $ 17,310 $ 191,220 $ 2,432 Liabilities: Derivatives $ — $ — $ — $ — Fair Value at December 31, 2014 Total Level 1 Level 2 Level 3 (In thousands) Assets: Investments in marketable securities $ 254,099 $ 5,145 $ 248,954 $ — Derivatives 13,557 9,026 1,491 3,040 Total assets $ 267,656 $ 14,171 $ 250,445 $ 3,040 Liabilities: Derivatives $ 766 $ — $ 766 $ — The Company’s contracts with its counterparties allow for the settlement of contracts in an asset position with contracts in a liability position in the event of default or termination. For classification purposes, the Company records the net fair value of all the positions with these counterparties as a net asset or liability. Each level in the table above displays the underlying contracts according to their classification in the accompanying consolidated balance sheet, based on this counterparty netting. The following table summarizes the change in the fair values of financial instruments categorized as level 3. Year Ended December 31, 2015 2014 (In thousands) Balance, beginning of period $ 3,040 $ 4,946 Realized and unrealized losses recognized in earnings, net (8,602 ) (6,572 ) Included in other comprehensive income (1,341 ) — Purchases 13,541 5,288 Issuances (4,046 ) (622 ) Settlements (160 ) — Ending balance $ 2,432 $ 3,040 Net unrealized losses of $2.7 million were recognized during the year ended December 31, 2015 related to level 3 financial instruments held on December 31, 2015 . Cash and Cash Equivalents At December 31, 2015 and 2014 , the carrying amounts of cash and cash equivalents approximate their fair value. Fair Value of Long-Term Debt At December 31, 2015 and 2014 , the fair value of the Company’s debt, including amounts classified as current, was $937.1 million and $2.7 billion , respectively. Fair values are based upon observed prices in an active market, when available, or from valuation models using market information, which fall into Level 2 in the fair value hierarchy.

Capital Stock

Capital Stock	12 Months Ended
	Dec. 31, 2015
Capital Stock [Abstract]
Capital Stock	Capital Stock Stock Repurchase Plan The Company's share repurchase program allows for the purchase of up to 1,400,000 shares of the Company's common stock. At December 31, 2015 , 1,092,580 shares of common stock were available for repurchase under the plan. There is no expiration date on the program. Any future repurchases under the plan will be made at management's discretion and will depend on market conditions and other factors. Reverse Stock Split On August 4, 2015, the Company effected a 1-for-10 reverse stock split of our common stock. Each stockholder's percentage ownership and proportional voting power remain unchanged as a result of the reverse stock split. All applicable share data, per share amounts and related information in the Consolidated Financial Statements and notes thereto have been adjusted retroactively to give effect to the 1-for-10 reverse stock split.

Stock-Based Compensation and Ot

Stock-Based Compensation and Other Incentive Plans	12 Months Ended
	Dec. 31, 2015
Share-based Compensation [Abstract]
Stock-Based Compensation And Other Incentive Plans	Stock-Based Compensation and Other Incentive Plans Under the Company's Stock Incentive Plan (the "Incentive Plan"), 3.1 million shares of the Company's common stock were reserved for awards to officers and other selected key management employees of the Company. The Incentive Plan provides the Board of Directors with the flexibility to grant stock options, stock appreciation rights, restricted stock awards, restricted stock units, performance stock or units, merit awards, phantom stock awards and rights to acquire stock through purchase under a stock purchase program ("Awards"). Awards the Board of Directors elects to pay out in cash do not impact the shares authorized in the Incentive Plan. Shares available for award under the plan were 1.0 million at December 31, 2015 . Stock Options Stock options are granted at a strike price equal to the closing market price of the Company's common stock on the date of grant and are generally subject to vesting provisions of at least one year from the date of grant. Information regarding stock option activity under the Incentive Plan follows for the year ended December 31, 2015 : Weighted Average Aggregate Average Common Exercise Intrinsic Remaining Shares Price Value Life (In thousands) (years) Options outstanding at January 1 682 $ 198.41 Canceled (17 ) $ 151.72 Expired (10 ) $ 300.62 Options outstanding at December 31 655 $ 198.15 $ — 4.6 Options exercisable at December 31 488 $ 213.00 — 4.4 Unvested options at December 31 167 The remaining unvested options have a weighted average grant date fair value of $35.47 per share. The total grant-date fair value of options vested during the years ended December 31, 2015 , 2014 and 2013 was $3.8 million , $8.7 million and $8.9 million , respectively. The options provide for the continuation of vesting for retirement-eligible recipients that meet certain criteria. The expense for these options is recognized through the date that the employee first becomes eligible to retire and is no longer required to provide service to earn part or all of the award. Compensation expense related to stock options for the years ended December 31, 2015 , 2014 and 2013 was $1.4 million , $3.2 million and $6.7 million , respectively. Unrecognized compensation cost related to the unvested stock options of $0.2 million at December 31, 2015 will be recognized in 2016.The majority of the cost relating to the stock-based compensation plans is included in "Selling, general and administrative expenses" in the accompanying consolidated statements of operations. Weighted average assumptions used in the Black-Scholes option pricing model for granted options follow: Year Ended December 31, 2013 Weighted average grant-date fair value per share of options granted $ 23.70 Assumptions (weighted average): Risk-free interest rate 0.65% Expected dividend yield 2.30% Expected volatility 66.7% Expected life (in years) 4.5 Expected volatilities are based on historical stock price movement and implied volatility from traded options on the Company's stock. The expected life of options is determined based on historical exercise activity. Restricted Stock and Restricted Stock Unit Awards The Company may issue restricted stock and restricted stock units, which require no payment from the employee. Restricted stock cliff-vests at various dates and restricted stock units either vest ratably over or vest at the end of three years . Compensation expense is based on the fair value on the grant date and is recorded ratably over the vesting period. The employee receives cash compensation equal to the amount of dividends that would have been paid on the underlying shares. Information regarding restricted stock and restricted stock unit activity and weighted average grant-date fair value follows for the year ended December 31, 2015 : Restricted Stock Restricted Stock Units Weighted Average Weighted Average Common Grant-Date Common Grant-Date Shares Fair Value Shares Fair Value (In thousands) (In thousands) Outstanding at January 1 2 $ 134.42 307 $ 60.53 Granted — — 169 12.84 Vested (2 ) 134.42 (66 ) 104.90 Canceled — — (21 ) 35.81 Outstanding at December 31 — — 389 33.69 The Company's recognized expense related to restricted stock and restricted stock units was $5.9 million , $5.6 million , and $5.0 million for the years ended December 31, 2015 , 2014 and 2013 , respectively Long-Term Incentive Compensation The Company has a long-term incentive program that allows for the award of performance units. The total number of units earned by a participant is based on financial and operational performance measures, and may be paid out in cash or in shares of the Company's common stock. The Company recognizes compensation expense over the three year term of the grant. The liabilities are remeasured quarterly. The Company recognized $7.9 million , $10.1 million and $9.1 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. The expense is included primarily in "Selling, general and administrative expenses" in the accompanying consolidated statements of operations. Amounts accrued and unpaid for all grants under the plan totaled $17.8 million and $21.1 million as of December 31, 2015 and 2014 , respectively. Deferred Compensation Plan The Company maintains a deferred compensation plan that allows eligible employees to defer receipt of compensation until the dates elected by the participant. Participants in the plan may defer up to 85% of their base salaries and up to 100% of their annual incentive awards. The plan also allows participants to defer receipt of up to 100% of the shares under any restricted stock unit or performance-contingent stock awards. The amounts deferred are invested in accounts that mirror the gains and losses of a number of different investment funds, including a hypothetical investment in shares of the Company's common stock. Participants are always vested in their deferrals to the plan and any related earnings. The Company has established a grantor trust to fund the obligations under the plan. The trust has purchased corporate-owned life insurance to offset these obligations. The net cash surrender values of the policies of $14.3 million and $37.6 million at December 31, 2015 and 2014 , respectively, are included in "Other noncurrent assets" in the accompanying consolidated balance sheets. The participants have an unsecured contractual commitment by the Company to pay the amounts due under the plan. Any assets placed in trust by the Company to fund future obligations of the plan are subject to the claims of creditors in the event of insolvency or bankruptcy, and participants are general creditors of the company as to their deferred compensation in the plans. Under the plan, the Company credits each participant's account with the number of units equal to the number of shares or units that the participant could purchase or receive with the amount of compensation deferred, based upon the fair market value of the underlying investment on that date. The amount the employee will receive from the plan will be based on the number of units credited to each participant's account, valued on the basis of the fair market value of an equivalent number of shares or units of the underlying investment on that date. The liability under the plan was $19.5 million and $35.1 million at December 31, 2015 and 2014 . The Company's net income related to the deferred compensation plan for the years ended December 31, 2015 , 2014 and 2013 was $0.9 million , $1.6 million and $2.6 million , respectively, most of which is included in "Selling, general and administrative expenses" in the accompanying consolidated statements of operations.

Workers' Compensation Expense

Workers' Compensation Expense	12 Months Ended
	Dec. 31, 2015
Workers' Compensation Expense [Abstract]
Workers' Compensation Expense	Workers’ Compensation Expense The following table details the components of workers’ compensation expense: Year Ended December 31, 2015 2014 2013 (In thousands) Total occupational disease $ 15,199 $ 4,432 $ 6,137 Traumatic injury claims and assessments 16,781 19,924 21,089 Total workers’ compensation expense $ 31,980 $ 24,356 $ 27,226 Summarized below is information about the amounts recognized in the accompanying consolidated balance sheets for workers' compensation benefits: December 31, 2015 2014 (In thousands) Occupational disease costs $ 90,836 $ 72,749 Traumatic and other workers' compensation claims 38,309 38,256 Total obligations 129,145 111,005 Less amount included in accrued expenses 16,875 16,714 Noncurrent obligations $ 112,270 $ 94,291 As of December 31, 2015 , the Company had $148.2 million in surety bonds and letters of credit outstanding to secure workers' compensation obligations.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2015
Pension and Other Postretirement Benefit Expense [Abstract]
Employee Benefit Plans	Employee Benefit Plans Defined Benefit Pension and Other Postretirement Benefit Plans The Company provides funded and unfunded non-contributory defined benefit pension plans covering certain of its salaried and hourly employees. Benefits are generally based on the employee's age and compensation. The Company funds the plans in an amount not less than the minimum statutory funding requirements or more than the maximum amount that can be deducted for U.S. federal income tax purposes. The Company also currently provides certain postretirement medical and life insurance coverage for eligible employees. Generally, covered employees who terminate employment after meeting eligibility requirements are eligible for postretirement coverage for themselves and their dependents. The salaried employee postretirement benefit plans are contributory, with retiree contributions adjusted annually, and contain other cost-sharing features such as deductibles and coinsurance. The Company's current funding policy is to fund the cost of all postretirement benefits as they are paid. The idling of the Cumberland River mining operations in Appalachia in the third quarter of 2014 reduced the estimated years of future service for the CRCC Scotia Employee Association Pension Plan. On January 1, 2015, the Company's cash balance and excess plans were amended to freeze new service credits for any new or active employee. These two events triggered curtailment accounting, resulting in an immediate recognition of any unamortized gain or loss and the reduction in the projected benefit obligation which were recorded in the third and fourth quarter of 2014, respectively. A curtailment was triggered in the third quarter of 2013 by reductions in employees' expected years of future service resulting primarily from the sale of Canyon Fuel. Obligations and Funded Status. Summaries of the changes in the benefit obligations, plan assets and funded status of the plans are as follows: Other Postretirement Pension Benefits Benefits 2015 2014 2015 2014 (In thousands) CHANGE IN BENEFIT OBLIGATIONS Benefit obligations at January 1 $ 353,736 $ 355,468 $ 36,098 $ 42,531 Service cost 9 21,478 866 1,649 Interest cost 14,604 17,070 1,904 1,841 Re-entry of former Magnum employees — — 85,843 — Plan amendments — (23 ) — — Curtailments — (25,787 ) — — Benefits paid (61,955 ) (53,974 ) (3,646 ) (3,431 ) Other-primarily actuarial loss (gain) (5,102 ) 39,504 (17,605 ) (6,492 ) Benefit obligations at December 31 $ 301,292 $ 353,736 $ 103,460 $ 36,098 CHANGE IN PLAN ASSETS Value of plan assets at January 1 $ 336,709 $ 347,952 $ — $ — Actual return on plan assets (1,679 ) 36,130 — — Employer contributions 424 6,601 3,646 3,431 Benefits paid (61,955 ) (53,974 ) (3,646 ) (3,431 ) Value of plan assets at December 31 $ 273,499 $ 336,709 $ — $ — Accrued benefit cost $ (27,793 ) $ (17,027 ) $ (103,460 ) $ (36,098 ) ITEMS NOT YET RECOGNIZED AS A COMPONENT OF NET PERIODIC BENEFIT COST Prior service credit (cost) $ — $ — $ 26,944 $ 21,972 Accumulated gain (loss) (16,769 ) (11,332 ) 11,313 9,125 $ (16,769 ) $ (11,332 ) $ 38,257 $ 31,097 BALANCE SHEET AMOUNTS Current liability $ (420 ) $ (767 ) $ (3,650 ) $ (3,430 ) Noncurrent liability $ (27,373 ) $ (16,260 ) $ (99,810 ) $ (32,668 ) $ (27,793 ) $ (17,027 ) $ (103,460 ) $ (36,098 ) Pension Benefits The accumulated benefit obligation for all pension plans was $301.3 million and $353.7 million at December 31, 2015 and 2014 , respectively. Net actuarial loss of $3.0 million will be amortized from accumulated other comprehensive income into net periodic benefit cost in 2016 . Other Postretirement Benefits Prior service credit and net actuarial gain of $10.7 million and $2.3 million , respectively, will be amortized from accumulated other comprehensive income into net periodic benefit cost in 2016 . Components of Net Periodic Benefit Cost . The following table details the components of pension and postretirement benefit costs (credits): Pension Benefits Other Postretirement Benefits Year Ended December 31, Year Ended December 31, 2015 2014 2013 2015 2014 2013 (In thousands) Service cost $ 9 $ 21,478 $ 27,065 $ 866 $ 1,649 $ 2,027 Interest cost 14,604 17,070 16,207 1,904 1,841 1,739 Curtailments — (25,368 ) 47 — — (5,444 ) Settlements 2,656 646 — — — — Expected return on plan assets (20,367 ) (23,756 ) (23,761 ) — — — Amortization of prior service credits — (257 ) (204 ) (8,335 ) (10,003 ) (10,621 ) Amortization of other actuarial losses 8,850 3,128 14,616 (2,109 ) (761 ) (252 ) Net benefit cost (credit) $ 5,752 $ (7,059 ) $ 33,970 $ (7,674 ) $ (7,274 ) $ (12,551 ) The differences generated from changes in assumed discount rates and returns on plan assets are amortized into earnings over a five-year period. Assumptions. The following table provides the weighted average assumptions used to determine the actuarial present value of projected benefit obligations at December 31 of the respective years. Pension Benefits Other Postretirement Benefits 2015 2014 2015 2014 Discount rate 4.59% 4.15% 4.57% 3.91% Rate of compensation increase N/A N/A N/A N/A The following table provides the weighted average assumptions used to determine net periodic benefit cost for the respective years ended December 31. Pension Benefits Other Postretirement Benefits 2015 2014 2013 2015 2014 2013 Discount rate 4.15% 5.08/ 4.23/ 4.14% 4.13/ 5.05% 3.91% 4.58% 3.64/ 4.58% Rate of compensation increase N/A N/A 3.39% N/A N/A N/A N/A Expected return on plan assets 7.00% 7.75% 7.75% N/A N/A N/A N/A The discount rates used in 2014 and 2013 were reevaluated during the year for settlements and the curtailments as described previously. The obligations are remeasured at an updated discount rate that impacts the benefit cost recognized subsequent to the remeasurement. 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 members of the Company's pension committee (the "Pension Committee"). 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. The health care cost trend rate assumed for 2016 is 7.1% and is expected to reach an ultimate trend rate of 4.5% by 2028 . A one-percentage-point increase in the health care cost trend rate would increase the postretirement benefit obligation at December 31, 2015 by $9.4 million and the net periodic postretirement benefit cost for the year ended December 31, 2015 by $0.1 million . Plan Assets The Pension Committee is responsible for overseeing the investment of pension plan assets. The Pension Committee is responsible for determining and monitoring appropriate asset allocations and for selecting or replacing investment managers, trustees and custodians. The pension plan's current investment targets are 60% equity and 40% fixed income securities. The Pension Committee reviews the actual asset allocation in light of these targets on a periodic basis and rebalances among investments as necessary. The Pension Committee evaluates the performance of investment managers as compared to the performance of specified benchmarks and peers and monitors the investment managers to ensure adherence to their stated investment style and to the plan's investment guidelines. The Company's pension plan assets at December 31, 2015 and 2014 , respectively, are categorized below according to the fair value hierarchy as defined in Note 17 , " Fair Value Measurements ": Total Level 1 Level 2 Level 3 2015 2014 2015 2014 2015 2014 2015 2014 (In thousands) Equity Securities: (A) U.S. small-cap $ 11,640 $ 16,512 $ 11,640 $ 16,512 $ — $ — $ — $ — U.S. mid-cap 28,524 46,481 10,979 17,301 17,545 29,180 — — U.S. large-cap 67,244 89,008 33,249 43,181 33,995 45,827 — — Non-U.S. 18,785 25,905 — — 18,785 25,905 — — Fixed income securities: — — — — — — — — U.S. government securities (B) 18,844 13,708 18,183 12,988 661 720 — — Non-U.S. government securities (C) 766 1,599 — — 766 1,599 — — U.S. government asset and mortgage backed securities (D) 1,056 830 — — 1,056 830 — — Corporate fixed income (E) 39,939 22,702 — — 39,939 22,702 — — State and local government securities (F) 5,725 8,005 — — 5,725 8,005 — — Other fixed income (G) 57,209 83,735 — — 57,209 83,735 — — Short-term investments (H) 3,898 6,818 — — 3,898 6,818 — — Other investments (I) 19,869 21,406 — — 1,234 3,336 18,635 18,070 Total $ 273,499 $ 336,709 $ 74,051 $ 89,982 $ 180,813 $ 228,657 $ 18,635 $ 18,070 (A) Equity securities includes investments in 1) common stock, 2) preferred stock and 3) mutual funds. Investments in common and preferred stocks are valued using quoted market prices multiplied by the number of shares owned. Investments in mutual funds are valued at the net asset value per share multiplied by the number of shares held as of the measurement date and are traded on listed exchanges. (B) U.S. government securities includes agency and treasury debt. These investments are valued using dealer quotes in an active market. (C) Non-U.S. government securities includes debt securities issued by foreign governments and are valued utilizing a price spread basis valuation technique with observable sources from investment dealers and research vendors. (D) U.S. government asset and mortgage backed securities includes government-backed mortgage funds which are valued utilizing an income approach that includes various valuation techniques and sources such as discounted cash flows models, benchmark yields and securities, reported trades, issuer trades and/or other applicable data. (E) Corporate fixed income is primarily comprised of corporate bonds and certain corporate asset-backed securities that are denominated in the U.S. dollar and are investment-grade securities. These investments are valued using dealer quotes. (F) State and local government securities include different U.S. state and local municipal bonds and asset backed securities, these investments are valued utilizing a market approach that includes various valuation techniques and sources such as value generation models, broker quotes, benchmark yields and securities, reported trades, issuer trades and/or other applicable data. (G) Other fixed income investments are actively managed fixed income vehicles that are valued at the net asset value per share multiplied by the number of shares held as of the measurement date. (H) Short-term investments include governmental agency funds, government repurchase agreements, commingled funds, and pooled funds and mutual funds. Governmental agency funds are valued utilizing an option adjusted spread valuation technique and sources such as interest rate generation processes, benchmark yields and broker quotes. Investments in governmental repurchase agreements, commingled funds and pooled funds and mutual funds are valued at the net asset value per share multiplied by the number of shares held as of the measurement date. (I) Other investments includes cash, forward contracts, derivative instruments, credit default swaps, interest rate swaps and mutual funds. Investments in interest rate swaps are valued utilizing a market approach that includes various valuation techniques and sources such as value generation models, broker quotes in active and non-active markets, benchmark yields and securities, reported trades, issuer trades and/or other applicable data. Forward contracts and derivative instruments are valued at their exchange listed price or broker quote in an active market. The mutual funds are valued at the net asset value per share multiplied by the number of shares held as of the measurement date and are traded on listed exchanges. During 2013, the plan invested $16.0 million in Level 3 investments. Subsequent changes in fair value are the result of unrealized gains on the investment. Cash Flows. The Company expects to make contributions of $0.5 million to the pension plans in 2016 , which is impacted by the Moving Ahead for Progress in the 21st Century Act (MAP-21). MAP-21 does not reduce the Company's obligations under the plan, but redistributes the timing of required payments by providing near term funding relief for sponsors under the Pension Protection Act. The following represents expected future benefit payments from the plan, which reflect expected future service, as appropriate: Other Pension Postretirement Benefits Benefits (In thousands) 2016 $ 19,164 $ 8,356 2017 20,320 8,341 2018 21,833 8,344 2019 21,341 8,281 2020 21,461 8,245 Next 5 years 106,953 38,178 $ 211,072 $ 79,745 Other Plans The Company sponsors savings plans which were established to assist eligible employees in providing for their future retirement needs. The Company's expense, representing its contributions to the plans, was $20.5 million , $22.9 million and $25.1 million for the years ended December 31, 2015 , 2014 and 2013 , respectively.

Loss Per Common Share

Loss Per Common Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Loss Per Common Share	Loss Per Common Share The effect of options, restricted stock and restricted stock units that were excluded from the calculation of diluted weighted average shares outstanding because the exercise price or grant price of the securities exceeded the average market price of the Company's common stock were: 1.0 million shares of common stock for the year ended December 31, 2015, and 0.8 million shares of common stock for each of the years ending December 31, 2014 and December 31, 2013. The weighted average share impacts of options, restricted stock and restricted stock units that were excluded from the calculation of weighted average shares due to the Company's incurring a net loss for the three years ending December 31, 2015, 2014 and 2013 were not significant.

Leases

Leases	12 Months Ended
	Dec. 31, 2015
Leases [Abstract]
Leases	Leases The Company leases equipment, land and various other properties under non-cancelable long-term leases, expiring at various dates. Certain leases contain options that would allow the Company to extend the lease or purchase the leased asset at the end of the base lease term. In addition, the Company enters into various non-cancelable royalty lease agreements under which future minimum payments are due. Minimum payments due in future years under these agreements in effect at December 31, 2015 are as follows: Operating Leases Royalties (In thousands) 2016 $ 20,857 $ 8,947 2017 17,277 13,991 2018 6,412 13,097 2019 3,448 12,295 2020 2,151 11,996 Thereafter 9,807 103,771 $ 59,952 $ 164,097 Obligations for the future minimum payments under capital leases for equipment totaling $40.0 million and $46.0. million at December 31, 2015 and 2014, respectively, are included in other long term debt obligations in Note 14 , " Debt and Financing Arrangements ". Rental expense, including amounts related to these operating leases and other shorter-term arrangements, amounted to $28.4 million in 2015 , $42.1 million in 2014 and $42.1 million in 2013. Royalties are paid to lessors either as a fixed price per ton or as a percentage of the gross selling price of the mined coal. Royalties under the majority of the Company's significant leases are paid on the percentage of gross selling price basis. Royalty expense, including production royalties, was $227.7 million in 2015, $242.5 million in 2014 and $261.1 million in 2013. As of December 31, 2015 , certain of the Company's lease obligations were secured by outstanding surety bonds totaling $49.4 million .

Risk Concentrations

Risk Concentrations	12 Months Ended
	Dec. 31, 2015
Risks Concentrations [Abstract]
Risk Concentrations	Risk Concentrations Credit Risk and Major Customers The Company has a formal written credit policy that establishes procedures to determine creditworthiness and credit limits for trade customers and counterparties in the over-the-counter coal market. Generally, credit is extended based on an evaluation of the customer's financial condition. Collateral is not generally required, unless credit cannot be established. Credit losses are provided for in the financial statements and historically have been minimal. The Company markets its steam coal principally to domestic and foreign electric utilities and its metallurgical coal to domestic and foreign steel producers. As of December 31, 2015 and 2014 , accounts receivable from electric utilities of $83.8 million and $134.7 million , respectively, represented 72% and 64% of total trade receivables at each date. As of December 31, 2015 and 2014 , accounts receivable from sales of metallurgical-quality coal of $32.8 million and $76.0 million , respectively, represented 28% and 36% of total trade receivables at each date. The Company uses shipping destination as the basis for attributing revenue to individual countries. Because title may transfer on brokered transactions at a point that does not reflect the end usage point, they are reflected as exports, and attributed to an end delivery point if that knowledge is known to the Company. The Company's foreign revenues by geographical location are as follows: Year Ended December 31, 2015 2014 2013 (In thousands) Europe $ 170,314 $ 277,565 $ 371,363 Asia 96,523 156,057 160,404 North America 40,315 78,445 80,322 Central and South America 55,323 20,496 55,493 Brokered Sales 32,848 79,354 154,442 Total $ 395,323 $ 611,917 $ 822,024 The Company is committed under long-term contracts to supply steam coal that meets certain quality requirements at specified prices. These prices are generally adjusted based on market indices. Quantities sold under some of these contracts may vary from year to year within certain limits at the option of the customer. The Company sold approximately 127.6 million tons of coal in 2015 . Approximately 68% of this tonnage (representing approximately 55% of the Company's revenues) was sold under long-term contracts (contracts having a term of greater than one year). Long-term contracts range in remaining life from one to five years. Third-party sources of coal The Company uses independent contractors to mine coal at certain mining complexes. The Company also purchases coal from third parties that it sells to customers. Factors beyond the Company's control could affect the availability of coal produced for or purchased by the Company. Disruptions in the quantities of coal produced for or purchased by the Company could impair its ability to fill customer orders or require it to purchase coal from other sources at prevailing market prices in order to satisfy those orders. Transportation The Company depends upon barge, rail, truck and belt transportation systems to deliver coal to its customers. Disruption of these transportation services due to weather-related problems, mechanical difficulties, strikes, lockouts, bottlenecks, and other events could temporarily impair the Company's ability to supply coal to its customers In the past, disruptions in rail service have resulted in missed shipments and production interruptions.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company accrues for cost related to contingencies when a loss is probable and the amount is reasonably determinable. Disclosure of contingencies is included in the financial statements when it is at least reasonably possible that a material loss or an additional material loss in excess of amounts already accrued may be incurred. Allegheny Energy Supply (“Allegheny”), the sole customer of coal produced at the Company's subsidiary Wolf Run Mining Company's (“Wolf Run”) Sycamore No. 2 mine, filed a lawsuit against Wolf Run, Hunter Ridge Holdings, Inc. (“Hunter Ridge”), and ICG in state court in Allegheny County, Pennsylvania on December 28, 2006, and amended its complaint on April 23, 2007. Allegheny claimed that Wolf Run breached a coal supply contract when it declared force majeure under the contract upon idling the Sycamore No. 2 mine in the third quarter of 2006, and that Wolf Run continued to breach the contract by failing to ship in volumes referenced in the contract. The Sycamore No. 2 mine was idled after encountering adverse geologic conditions and abandoned gas wells that were previously unidentified and unmapped. After extensive searching for gas wells and rehabilitation of the mine, it was re-opened in 2007, but with notice to Allegheny that it would necessarily operate at reduced volumes in order to safely and effectively avoid the many gas wells within the reserve. The amended complaint also alleged that the production stoppages constitute a breach of the guarantee agreement by Hunter Ridge and breach of certain representations made upon entering into the contract in early 2005. Allegheny voluntarily dropped the breach of representation claims later. Allegheny claimed that it would incur costs in excess of $100 million to purchase replacement coal over the life of the contract. ICG, Wolf Run and Hunter Ridge answered the amended complaint on August 13, 2007, disputing all of the remaining claims. On November 3, 2008, ICG, Wolf Run and Hunter Ridge filed an amended answer and counterclaim against the plaintiffs seeking to void the coal supply agreement due to, among other things, fraudulent inducement and conspiracy. On September 23, 2009, Allegheny filed a second amended complaint alleging several alternative theories of liability in its effort to extend contractual liability to ICG, which was not a party to the original contract and did not exist at the time Wolf Run and Allegheny entered into the contract. No new substantive claims were asserted. ICG answered the second amended complaint on October 13, 2009, denying all of the new claims. The Company's counterclaim was dismissed on motion for summary judgment entered on May 11, 2010. Allegheny's claims against ICG were also dismissed by summary judgment, but the claims against Wolf Run and Hunter Ridge were not. The court conducted a non-jury trial of this matter beginning on January 10, 2011 and concluding on February 1, 2011. At the trial, Allegheny presented its evidence for breach of contract and claimed that it is entitled to past and future damages in the aggregate of between $228 million and $377 million . Wolf Run and Hunter Ridge presented their defense of the claims, including evidence with respect to the existence of force majeure conditions and excuse under the contract and applicable law. Wolf Run and Hunter Ridge presented evidence that Allegheny's damages calculations were significantly inflated because it did not seek to determine damages as of the time of the breach and in some instances artificially assumed future nondelivery or did not take into account the apparent requirement to supply coal in the future. On May 2, 2011, the trial court entered a Memorandum and Verdict determining that Wolf Run had breached the coal supply contract and that the performance shortfall was not excused by force majeure. The trial court awarded total damages and interest in the amount of $104.1 million , which consisted of $13.8 million for past damages, and $90.3 million for future damages. ICG and Allegheny filed post-verdict motions in the trial court and on August 23, 2011, the court denied the parties' motions. The court entered a final judgment on August 25, 2011, in the amount of $104.1 million , which included pre-judgment interest. The parties appealed the lower court's decision to the Superior Court of Pennsylvania. On August 13, 2012, the Superior Court of Pennsylvania affirmed the award of past damages, but ruled that the lower court should have calculated future damages as of the date of breach, and remanded the matter back to the lower court with instructions to recalculate that portion of the award. On November 19, 2012, Allegheny filed a Petition for Allowance of Appeal with the Supreme Court of Pennsylvania and Wolf Run and Hunter Ridge filed an Answer. On July 2, 2013, the Supreme Court of Pennsylvania denied the Petition of Allowance. As this action finalized the past damage award, Wolf Run paid $15.6 million for the past damage amount, including interest, to Allegheny in July 2013. The court held a hearing on this matter on November 5, 2014 and on February 16, 2015 awarded Allegheny $7.5 million plus interest for the future damages. On April 6, 2015, the parties entered into a settlement agreement pursuant to which Wolf Run agreed to pay $15 million and both parties agreed to release and discharge the other party from any further contractual liability. As a result, the Company accrued an additional $2.8 million during the first quarter of 2015 to bring the total amount accrued up to the settlement amount which was paid during April 2015. The expense associated with the accrual is reflected in the line item “Cost of sales”. In addition, the Company is a party to numerous claims and lawsuits with respect to various matters. As of December 31, 2015 and 2014 , the Company had accrued $2.8 million and $22.3 million , respectively, for all legal matters, including $2.8 million and $10.1 million , respectively, classified as current. The ultimate resolution of any such legal matter could result in outcomes which may be materially different from amounts the Company has accrued for such matters. The Company has unconditional purchase obligations relating to purchases of coal, materials and supplies and capital commitments, other than reserve acquisitions, and is also a party to transportation capacity commitments. The future commitments under these agreements total $94.6 million in 2016 , $25.4 million in 2017 , $10.6 million in 2018 , $11.3 million in 2019 , $11.6 million in 2020 and $11.1 million thereafter. During the years ended December 31, 2015 , 2014 and 2013 , the Company fulfilled its commitments under agreements containing unconditional obligations. The Company recognized expense relating to transportation capacity agreements of $52.9 million , $36.5 million , and $12.0 million during the years ended December 31, 2015 , 2014 and 2013 , respectively.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Filing Under Chapter 11 of the United States Bankruptcy Code On January 11, 2016 (the “Petition Date”), the Company and substantially all of its wholly owned domestic subsidiaries (the “Filing Subsidiaries” and, together with the Company, the “Debtors”) filed voluntary petitions for reorganization (collectively, the “Bankruptcy Petitions”) under Chapter 11 of Title 11 of the U.S. Code (the “Bankruptcy Code”) in the United States Bankruptcy Court for the Eastern District of Missouri (the “Court”). The Debtor’s Chapter 11 Cases (collectively, the “Chapter 11 Cases”) are being jointly administered under the caption In re Arch Coal, Inc., et al. Case No. 16-40120 (lead case). Each Debtor will continue to operate its business as a “debtor in possession” under the jurisdiction of the Court and in accordance with the applicable provisions of the Bankruptcy Code and the orders of the Court. The filing of the Bankruptcy Petitions constituted an event of default that accelerated the Company's obligations under the documents governing each of its 7.00% senior notes due 2019, 9.875% senior notes due 2019, 8.00% senior secured second lien notes due 2019, 7.25% senior notes due 2020, 7.25% senior notes due 2021 (together, the “senior notes”) and senior secured first lien term loan due 2018 (the “Existing Credit Agreement”) (collectively with the senior notes, the “Debt Instruments”), all as further described in Note 14, "Debt and Financing Arrangements." Immediately after filing the Bankruptcy Petitions, the Company began notifying all known current or potential creditors of the Debtors of the bankruptcy filings. Additionally, on the Petition Date, the New York Stock Exchange (the “NYSE”) determined that the Company's common stock was no longer suitable for listing pursuant to Section 8.02.01D of the NYSE continued listing standards and trading in the Company’s common stock was suspended on January 11, 2016. We expect that the existing common stock of the Company will be extinguished upon the Company's emergence from Chapter 11 and existing equity holders will not receive consideration in respect of their equity interests. On the Petition Date, the Debtors filed a number of motions with the Court generally designed to stabilize their operations and facilitate the Debtors’ transition into Chapter 11. Certain of these motions sought authority from the Court for the Debtors to make payments upon, or otherwise honor, certain pre-petition obligations (e.g., obligations related to certain employee wages, salaries and benefits and certain vendors and other providers essential to the Debtors’ businesses). The Court has entered orders approving the relief sought in these motions, in certain cases on an interim basis. Pursuant to Section 362 of the Bankruptcy Code, the filing of the Bankruptcy Petitions automatically stayed most actions against the Debtors, including actions to collect indebtedness incurred prior to the Petition Date or to exercise control over the Debtors’ property. Subject to certain exceptions under the Bankruptcy Code, the filing of the Debtors’ Chapter 11 Cases also automatically stayed the continuation of most legal proceedings, including the third party litigation matters described under Item 3, “Legal Proceedings,” or the filing of other actions against or on behalf of the Debtors or their property to recover on, collect or secure a claim arising prior to the Petition Date or to exercise control over property of the Debtors’ bankruptcy estates, unless and until the Court modifies or lifts the automatic stay as to any such claim. Notwithstanding the general application of the automatic stay described above, governmental authorities may determine to continue actions brought under their police and regulatory powers. As required by the Bankruptcy Code, the U.S. Trustee for the Eastern District of Missouri appointed an official committee of unsecured creditors (the “Creditors’ Committee”) on January 25, 2016. The Creditors’ Committee represents all unsecured creditors of the Debtors and has a right to be heard on all matters that come before the Court. Restructuring Support Agreement In connection with the filing of the Bankruptcy Petitions, the Company entered into a Restructuring Support Agreement, dated as of January 10, 2016 (the “Restructuring Support Agreement”), among the Debtors and holders of over 50% of the Company's first lien term loans under the Existing Credit Agreement (the “Supporting First Lien Creditors”), providing that the Supporting First Lien Creditors will support a restructuring of the Debtors, subject to the following terms and conditions contemplated therein, among others: • existing common stock of the Company would likely be extinguished upon the Company's emergence from Chapter 11, and existing equity holders would likely not receive consideration in respect of their equity interests; • claims against the Debtors arising under the DIP Financing (as defined below) would be paid in full in cash or receive such other treatment as may be consented to by the holders of such claims; • claims against the Debtors of holders of first lien term loans would be exchanged for (a) a combination of cash and $326.5 million (principal amount) of new first lien debt that would be issued by the reorganized Company and (b) 100% of the common stock of the reorganized Company outstanding on the effective date of the plan, subject to dilution on account of a proposed new management incentive plan and the distribution to unsecured creditors of any new common stock and warrants (as described below); • first lien term loan deficiency claims (subject to certain exceptions) as well as second lien notes, unsecured notes and general unsecured claims against the Debtors would be exchanged for either (1) common stock in the reorganized Company and warrants or (2) the value of the unencumbered assets of the Company, if any, after giving effect to certain other payments and claims; • either the Company’s existing accounts receivable securitization facility would be reinstated or a new letter of credit facility would be entered into by the Company, in either case on terms acceptable to Supporting First Lien Creditors holding more than 66 2/3% of the aggregate amount of the first lien term loans held by Supporting First Lien Creditors; and • the board of directors of the reorganized Company would consist of seven directors, at least one of whom would be independent, including the Company’s Chief Executive Officers and six directors selected by certain of the Company’s first-lien term lenders in consultation with the Company’s Chief Executive Officer. The Restructuring Support Agreement, if utilized as the basis for a plan of reorganization, is expected to reduce the Company's long-term debt by more than $4.5 billion . On January 21, 2016, the Debtors filed a motion with the Court seeking to assume and perform under the Restructuring Support Agreement. Securitization Agreement On January 13, 2016, the Company agreed with its securitization financing providers (the “Securitization Financing Providers”) that, subject to certain amendments (the “Amendments”), they will continue the $200 million trade accounts receivable securitization facility provided to Arch Receivable Company, LLC, a non-debtor special-purpose entity that is a wholly owned subsidiary of the Company (“Arch Receivable”) (the “Securitization Facility”). Pursuant to the Amendments, which have been approved by the Court on a final basis, the Debtors agreed to a revised schedule of fees payable to the administrator and the Securitization Financing Providers. The cost of an advance backstopping a letter of credit issued under the Securitization Facility is determined by two factors: (a) a program fee of 2.65% per year and payable on each settlement date to each Securitization Financing Provider deemed to have made such an advance and (b) the “discount,” which is calculated based on each Securitization Financing Provider’s costs, including its cost of the issuance and placement of short term promissory notes to fund such an advance. In connection with the Securitization Facility, Arch Receivable has granted to the administrator (for the benefit of the securitization purchasers) a first priority security interest in all of its assets, including all outstanding accounts receivable generated by the Debtors from the sale of coal and sold through the Securitization Facility (including collections, proceeds and certain other interests related thereto) (the “Receivables”) and all proceeds thereof. The agreements governing the Securitization Facility provide for the grant of analogous security interests by certain Debtors that generate Receivables from the sale of coal (such Debtors, the “Originators”). The agreements expressly state that the transfers of Receivables from the Originators to Arch and from Arch to Arch Receivable are intended to be true sales of the Receivables. However, if, against the intent of the parties (and notwithstanding entry of an order by the Court which provides that the transfers of the Receivables constitute true sales), any such transfer is recharacterized as a loan or extension of credit, each Originator has granted a first priority prepetition security interest in the Receivables and certain related collateral, pursuant to the agreements governing the Securitization Facility, for the ultimate benefit of the administrator and the Securitization Financing Providers (the “Liens”). The Debtors have agreed, in connection with the Amendments, to effectively extend such Liens to cover Receivables generated on or after the Petition Date. The Originators do not guarantee the collection of Receivables that have been transferred to Arch Receivable. However, the Originators are obligated to reimburse Arch Receivable for inaccuracy of certain representations and warranties, dilution items with respect to Receivables and certain other limited indemnities (such obligations, the “Repayment Amounts”). Under the agreements governing the Securitization Facility, Arch Receivable is entitled to apply Repayment Amounts to amounts owed under the Securitization Facility. Further, the Company has executed a performance guarantee through which it has promised to fulfill, or cause Arch Receivable, the designated servicer and each Originator to fulfill, each of their obligations under the agreements governing the Securitization Facility. In addition, as contemplated by the Amendments, the Originators have also executed a performance guarantee promising to fulfill obligations of all Originators under the agreements. In addition, in connection with the Amendments, the Debtors have granted superpriority claims against the Debtors and in favor of Arch Receivable, the administrator and the Securitization Financing Providers in respect of certain of the Debtors’ obligations under the agreements governing the Securitization Facility, including the Repayment Amounts and certain other limited indemnification and other obligations of the Debtors under the agreements. Debtor-In-Possession Financing On January 21, 2016, the Superpriority Secured Debtor-in-Possession Credit Agreement as amended by the waiver and consent and Amendment No. 1, dated as of March 4, 2016, (the “DIP Credit Agreement”) was entered into by and among the Company, as borrower, certain of the Debtors, as guarantors (the “Guarantors” and, together with the Company, the “Loan Parties”), the lenders from time to time party thereto (the “DIP Lenders”) and Wilmington Trust, National Association, as administrative agent and collateral agent for the DIP Lenders (in such capacities, the “DIP Agent”). The DIP Credit Agreement, which has been approved by the Court on a final basis, provides for a super-priority senior secured debtor-in-possession credit facility (the “DIP Facility”) consisting of term loans (collectively, the “DIP Term Loan”) in the aggregate principal amount of up to $275 million that may be funded in not more than two draws not later than six months after the effective date of the DIP Facility (such six month period, the “Availability Period”). Any portion of the DIP Term Loan commitment that has not been funded on or prior to the end of the Availability Period will be permanently cancelled. The maturity date of the DIP Facility is the earliest of (i) January 31, 2017, (ii) the date of the substantial consummation of a plan of reorganization that is confirmed pursuant to an order of the Court, (iii) the consummation of the sale of all or substantially all of the assets of the Loan Parties pursuant to Section 363 of the Bankruptcy Code and (iv) the date the obligations under the DIP Facility are accelerated pursuant to the terms of the DIP Credit Agreement. Borrowings under the DIP Facility bear interest at an interest rate per annum equal to, at the Company’s option (i) LIBOR plus 9.00% , subject to a 1.00% LIBOR floor or (ii) the base rate plus 8.00% . Obligations under the DIP Credit Agreement will be guaranteed on a super-priority senior secured basis by all existing and future wholly-owned domestic subsidiaries of Arch, and all newly created or acquired wholly-owned domestic subsidiaries of Arch, subject to customary limited exceptions. The lenders under the DIP Credit Agreement will have a first priority lien on all encumbered and unencumbered assets of the Loan Parties (the “DIP Lien”), subject to a $75 million carve-out for super-priority claims relating to the Debtors’ bonding obligations, a customary professional fees carve-out and certain exceptions. The Loan Parties are subject to certain financial maintenance covenants under the DIP Credit Agreement, including, without limitation, (i) maximum capital expenditures and (ii) minimum liquidity (defined as unrestricted cash and cash equivalents of the Company and its domestic subsidiaries (other than any securitization subsidiary or bonding subsidiary), plus withdrawable funds from brokerage accounts of the Company and its domestic subsidiaries (other than any securitization subsidiary or bonding subsidiary) plus any unused commitments that are available to be drawn by the Company pursuant to the terms of the DIP Credit Agreement) of (A) $300 million prior to the entry of the Final Order and (B) $500 million following the entry of the Final Order, in each case tested on a monthly basis. The DIP Credit Agreement contains customary affirmative and negative covenants and representations for debtor-in-possession financings. In addition to customary events of default for debtor-in-possession financings, the DIP Credit Agreement contains milestones relating to the Chapter 11 Cases and any failure to comply with such milestones constitutes an event of default. The DIP Facility is subject to certain usual and customary prepayment events, including 100% of net cash proceeds of (i) debt issuances (other than debt permitted to be incurred under the terms of the DIP Credit Agreement), (ii) non-ordinary course asset sales or dispositions in excess of $50 million in the aggregate (with no individual asset sale or disposition in excess of $7.5 million ) and (iii) any casualty event in excess of $50 million in the aggregate, subject to customary reinvestment rights, in each case to be applied to prepay the DIP Term Loan. At a hearing held on February 23, 2016 in the Chapter 11 Cases, the Court approved the DIP Financing on a final basis, overruling the objections of the Creditors' Committee and certain other parties who asserted, among other things, that the DIP Financing was unnecessary and argued that the Debtors should enter into an alternate debtor-in-possession financing facility proposed by certain members of the Creditors' Committee. Other Non-Bankruptcy Items On February 1, 2016, a mining company that Arch Coal, Inc. leases coal reserves to in Kentucky announced plans to idle its mining operations related to those reserves. At December 31, 2015, the Company had a net book value of $66.8 million on the approximate 22.0 million tons of reserves. As a result, the company will record an impairment charge representing the remaining net book value of the reserves in the first quarter of 2016.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Segment Information	Segment Information The Company's reportable business segments are based on the major coal producing basins in which the Company operates and may include a number of mine complexes. The Company manages its coal sales by coal basin, not by individual mining complex. Geology, coal transportation routes to customers, regulatory environments and coal quality or type are characteristic to a basin, and, accordingly, market and contract pricing have developed by coal basin. Mining operations are evaluated based on their per-ton operating costs (defined as including all mining costs but excluding pass-through transportation expenses), as well as on other non-financial measures, such as safety and environmental performance. The Company’s reportable segments are the Powder River Basin (PRB) segment, with operations in Wyoming; and the Appalachia (APP) segment, with operations in West Virginia, Kentucky, Maryland and Virginia. “All Other” includes the Company’s coal mining operations in Colorado and Illinois and the ADDCAR subsidiary (which was sold during the first quarter of 2014). Operating segment results for the years ended December 31, 2015 , 2014 and 2013 are presented below. The Company measures its segments based on "adjusted earnings before interest, taxes, depreciation, depletion and amortization (Adjusted EBITDA)." The Company's management believes that Adjusted EBITDA presents a useful measure of our ability to service existing debt and incur additional debt based on ongoing operations. Adjusted EBITDA does not reflect mine closure or impairment costs, since those are not reflected in the operating income reviewed by management. See Note 5 , " Impairment Charges and Mine Closure Costs " for discussion of these costs. The Corporate, Other and Eliminations grouping includes these charges, as well as the change in fair value of coal derivatives and coal trading activities, net; corporate overhead; land management activities; other support functions; and the elimination of intercompany transactions. The asset amounts below represent an allocation of assets consistent with the basis used for the Company’s incentive compensation plans. The amounts in Corporate, Other and Eliminations represent primarily corporate assets (cash, receivables, investments, plant, property and equipment) as well as unassigned coal reserves, above-market acquired sales contracts and other unassigned assets. PRB APP All Other Corporate, Other and Eliminations Consolidated Year Ended December 31, 2015 Revenues $ 1,448,440 $ 834,606 $ 290,214 $ — $2,573,260 Adjusted EBITDA 258,300 82,837 17,044 (108,064 ) 250,117 Depreciation, depletion and amortization 176,257 156,273 40,768 6,047 379,345 Amortization of acquired sales contracts, net (4,158 ) (4,653 ) — — (8,811 ) Total assets 1,648,916 843,583 310,949 2,303,290 5,106,738 Capital expenditures 22,535 20,599 11,135 64,755 119,024 Year Ended December 31, 2014 Revenues $ 1,490,377 $ 1,108,358 $ 338,384 $ — $ 2,937,119 Adjusted EBITDA 198,074 110,693 56,612 (85,236 ) 280,143 Depreciation, depletion and amortization 168,522 205,732 40,125 4,369 418,748 Amortization of acquired sales contracts, net (3,961 ) (9,433 ) 207 — (13,187 ) Total assets 1,772,230 3,379,834 339,809 2,937,850 8,429,723 Capital expenditures 44,305 23,638 12,993 66,350 147,286 Year Ended December 31, 2013 Revenues $ 1,482,812 $ 1,145,801 $ 385,744 $ — $ 3,014,357 Adjusted EBITDA 206,910 88,883 94,948 (138,595 ) 252,146 Depreciation, depletion and amortization 171,324 202,952 45,741 6,425 426,442 Amortization of acquired sales contracts, net (3,656 ) (10,364 ) 4,563 — (9,457 ) Total assets 1,841,835 3,971,764 402,922 2,773,672 8,990,193 Capital expenditures 9,784 167,759 23,122 96,319 296,984 A reconciliation of segment losses to consolidated loss from continuing operations before income taxes follows: Year Ended December 31, 2015 2014 2013 Adjusted EBITDA $ 250,117 $ 280,143 $ 252,146 Depreciation, depletion and amortization (379,345 ) (418,748 ) (426,442 ) Amortization of acquired sales contracts, net 8,811 13,187 9,457 Asset impairment costs (2,628,303 ) (24,113 ) (220,879 ) Goodwill impairment — — (265,423 ) Losses from disposed operations resulting from Patriot Coal bankruptcy (116,343 ) — — Settlement of UMWA legal claims — — (12,000 ) Interest expense, net (393,549 ) (383,188 ) (374,664 ) Nonoperating expense (27,910 ) — (42,921 ) Loss from continuing operations before income taxes $ (3,286,522 ) $ (532,719 ) $ (1,080,726 )

Quarterly Selected Financial Da

Quarterly Selected Financial Data (unaudited)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Quarterly Selected Financial Data (unaudited)	Quarterly Selected Financial Data (unaudited) Year Ended December 31, 2015 March 31 June 30 September 30 December 31 (a) (a) (a) (a) (In thousands, except per share data) Revenues $ 677,005 $ 644,462 $ 688,544 563,249 Gross profit (loss) $ 14,256 $ (16,507 ) $ 47,275 (44,964 ) Asset impairment and mine closure costs $ — $ 19,146 $ 2,120,292 488,865 Loss from operations $ (19,712 ) $ (69,546 ) $ (2,236,772 ) $ (539,033 ) Net loss $ (113,195 ) $ (168,103 ) $ (1,999,476 ) $ (632,368 ) Diluted loss per common share $ (5.32 ) $ (7.93 ) $ (93.91 ) $ (29.70 ) Year Ended December 31, 2014 March 31 June 30 September 30 December 31 (a) (a) (b) (a) (b) (a) (b) (In thousands, except per share data) Revenues $ 735,971 $ 713,776 $ 742,180 $ 745,192 Gross profit (loss) $ (49,842 ) $ (6,350 ) $ (5,851 ) $ 32,264 Asset impairment and mine closure costs $ — $ 1,512 $ 5,060 $ 17,541 Loss from operations $ (73,123 ) $ (35,805 ) $ (35,300 ) $ (5,303 ) Net loss $ (124,140 ) $ (96,860 ) $ (97,218 ) $ (240,135 ) Diluted loss per common share $ (5.85 ) $ (4.57 ) $ (4.58 ) $ (11.31 ) (a) Challenging coal markets resulted in impairment charges relating to mining and other operations, investments in equity method subsidiaries and prepaid mining royalties in 2015 and 2014. See further discussion in Note 5 , " Impairment Charges and Mine Closure Costs " and Note 10 , " Equity Method Investments and Membership Interests in Joint Ventures ." (b) The Company determined that it would not realize the benefit from federal and state net operating losses it generated in 2014, based on projections of future taxable income, and as a result, recorded a valuation allowance against net operating losses of $23.8. million , $18.3 million , $15.8 million and $807.2 million in the second, third and fourth quarters of 2014, respectively.

Supplemental Consolidating Fina

Supplemental Consolidating Financial Information	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Supplemental Consolidating Financial Information	Supplemental Consolidating Financial Information Pursuant to the indentures governing Arch Coal, Inc.’s senior notes, certain wholly-owned subsidiaries of the Company have fully and unconditionally guaranteed the senior notes on a joint and several basis. The following tables present consolidating financial information for (i) the Company, (ii) the issuer of the senior notes, (iii) the guarantors under the senior notes, and (iv) the entities which are not guarantors under the senior notes (Arch Receivable Company, LLC and the Company’s subsidiaries outside the United States): Condensed Consolidating Statements of Operations and Comprehensive Income Year Ended December 31, 2015 Parent/Issuer Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated (In thousands) Revenues $ — $ 2,573,260 $ — $ — $ 2,573,260 Costs, expenses and other Cost of sales (exclusive of items shown separately below) 22,378 2,186,804 — (2,749 ) 2,206,433 Depreciation, depletion and amortization 3,775 375,568 2 — 379,345 Amortization of acquired sales contracts, net — (8,811 ) — — (8,811 ) Change in fair value of coal derivatives and coal trading activities, net — (1,583 ) — — (1,583 ) Asset impairment and mine closure costs 15,437 2,612,866 — — 2,628,303 Losses from disposed operations resulting from Patriot Coal bankruptcy 116,343 — — — 116,343 Selling, general and administrative expenses 69,384 25,737 5,725 (2,063 ) 98,783 Other operating expense (income), net 5,869 13,021 (4,192 ) 4,812 19,510 233,186 5,203,602 1,535 — 5,438,323 Loss from investment in subsidiaries (2,574,565 ) — — 2,574,565 — Loss from operations (2,807,751 ) (2,630,342 ) (1,535 ) 2,574,565 (2,865,063 ) Interest expense, net Interest expense (478,432 ) (26,284 ) (4,916 ) 111,653 (397,979 ) Interest and investment income 27,510 82,881 5,692 (111,653 ) 4,430 (450,922 ) 56,597 776 — (393,549 ) Net loss resulting from early retirement of debt and debt restructuring (27,910 ) — — — (27,910 ) Loss from continuing operations before income taxes (3,286,583 ) (2,573,745 ) (759 ) 2,574,565 (3,286,522 ) Provision for (benefit from) income taxes (373,441 ) — 61 — (373,380 ) Net loss (2,913,142 ) (2,573,745 ) (820 ) 2,574,565 (2,913,142 ) Total comprehensive loss $ (2,918,198 ) $ (2,579,601 ) $ (820 ) $ 2,580,421 $ (2,918,198 ) Condensed Consolidating Statements of Operations and Comprehensive Income Year Ended December 31, 2014 Parent/Issuer Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated (In thousands) Revenues $ — $ 2,937,119 $ — $ — $ 2,937,119 Costs, expenses and other Cost of sales (exclusive of items shown separately below) 3,016 2,566,572 — (3,395 ) 2,566,193 Depreciation, depletion and amortization 5,154 413,559 35 — 418,748 Amortization of acquired sales contracts, net — (13,187 ) — — (13,187 ) Change in fair value of coal derivatives and coal trading activities, net — (3,686 ) — — (3,686 ) Asset impairment and mine closure costs 3,642 20,471 — — 24,113 Selling, general and administrative expenses 79,902 29,739 6,626 (2,044 ) 114,223 Other operating income, net (4,480 ) (15,726 ) (4,987 ) 5,439 (19,754 ) 87,234 2,997,742 1,674 — 3,086,650 Loss from investment in subsidiaries (13,085 ) — — 13,085 — Loss from operations (100,319 ) (60,623 ) (1,674 ) 13,085 (149,531 ) Interest expense, net Interest expense (463,823 ) (26,137 ) (4,259 ) 103,273 (390,946 ) Interest and investment income 31,389 74,511 5,131 (103,273 ) 7,758 (432,434 ) 48,374 872 — (383,188 ) Loss from continuing operations before income taxes (532,753 ) (12,249 ) (802 ) 13,085 (532,719 ) Provision for (benefit from) income taxes 25,600 — 34 — 25,634 Net loss (558,353 ) (12,249 ) (836 ) 13,085 (558,353 ) Total comprehensive loss $ (592,804 ) $ (34,439 ) $ (836 ) $ 35,275 $ (592,804 ) Condensed Consolidating Statements of Operations and Comprehensive Income Year Ended December 31, 2013 Parent/Issuer Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated (In thousands) Revenues $ — $ 3,014,357 $ — $ — $ 3,014,357 Costs, expenses and other — Cost of sales (exclusive of items shown separately below) 9,117 2,657,583 — (3,564 ) 2,663,136 Depreciation, depletion and amortization 5,949 420,458 35 — 426,442 Amortization of acquired sales contracts, net — (9,457 ) — — (9,457 ) Change in fair value of coal derivatives and coal trading activities, net — 7,845 — — 7,845 Asset impairment and mine closure costs 78,150 142,729 — — 220,879 Goodwill impairment — 265,423 — — 265,423 Selling, general and administrative expenses 88,820 39,825 7,038 (2,235 ) 133,448 Other operating income, net 4,209 (34,856 ) (5,370 ) 5,799 (30,218 ) 186,245 3,489,550 1,703 — 3,677,498 Loss from investment in subsidiaries (328,889 ) — — 328,889 — Income (loss) from operations (515,134 ) (475,193 ) (1,703 ) 328,889 (663,141 ) Interest expense, net Interest expense (449,614 ) (24,747 ) (4,214 ) 97,308 (381,267 ) Interest and investment income 30,285 68,248 5,378 (97,308 ) 6,603 (419,329 ) 43,501 1,164 — (374,664 ) Other non-operating expense Net loss resulting from early retirement of debt (42,921 ) — — — (42,921 ) Loss from continuing operations before income taxes (977,384 ) (431,692 ) (539 ) 328,889 (1,080,726 ) Provision for (benefit from) income taxes (335,552 ) — 54 — (335,498 ) Loss from continuing operations (641,832 ) (431,692 ) (593 ) 328,889 (745,228 ) Income from discontinued operations, net of tax — 103,396 — — 103,396 Net Loss (641,832 ) (328,296 ) (593 ) 328,889 (641,832 ) Total comprehensive income (loss) $ (587,633 ) $ (304,278 ) $ (593 ) $ 304,871 $ (587,633 ) Condensed Consolidating Balance Sheets December 31, 2015 Parent/Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated (In thousands) Assets Cash and cash equivalents $ 337,646 $ 100,428 $ 12,707 $ — $ 450,781 Short term investments 200,192 — — — 200,192 Restricted cash — — 97,542 — 97,542 Receivables 12,463 3,153 124,581 (4,430 ) 135,767 Inventories — 196,720 — — 196,720 Other 83,017 38,794 969 — 122,780 Total current assets 633,318 339,095 235,799 (4,430 ) 1,203,782 Property, plant and equipment, net 7,747 3,610,869 — 413 3,619,029 Investment in subsidiaries 4,887,905 — — (4,887,905 ) — Intercompany receivables — 2,253,312 — (2,253,312 ) — Note receivable from Arch Western 675,000 — — (675,000 ) — Other 39,302 243,806 819 — 283,927 Total assets $ 6,243,272 $ 6,447,082 $ 236,618 $ (7,820,234 ) $ 5,106,738 Liabilities and Stockholders’ Equity (Deficit) Accounts payable $ 8,495 $ 119,633 $ 3 $ — $ 128,131 Accrued expenses and other current liabilities 162,268 170,575 1,037 (4,430 ) 329,450 Current maturities of debt 5,096,460 10,750 — — 5,107,210 Total current liabilities 5,267,223 300,958 1,040 (4,430 ) 5,564,791 Long-term debt — 30,953 — — 30,953 Intercompany payables 2,043,308 — 210,005 (2,253,313 ) — Note payable to Arch Coal — 675,000 — (675,000 ) — Asset retirement obligations 1,005 395,654 — — 396,659 Accrued pension benefits 12,390 14,983 — — 27,373 Accrued postretirement benefits other than pension 79,826 19,984 — — 99,810 Accrued workers’ compensation 24,247 88,023 — — 112,270 Deferred income taxes — — — — — Other noncurrent liabilities 59,976 58,847 348 — 119,171 Total liabilities 7,487,975 1,584,402 211,393 (2,932,743 ) 6,351,027 Stockholders’ equity (deficit) (1,244,703 ) 4,862,680 25,225 (4,887,491 ) (1,244,289 ) Total liabilities and stockholders’ equity (deficit) $ 6,243,272 $ 6,447,082 $ 236,618 $ (7,820,234 ) $ 5,106,738 Condensed Consolidating Balance Sheets December 31, 2014 Parent/Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated (In thousands) Assets Cash and cash equivalents $ 572,185 $ 150,358 $ 11,688 $ — $ 734,231 Short term investments 248,954 — — — 248,954 Restricted cash — — 5,678 — 5,678 Receivables 9,656 15,933 211,043 (4,615 ) 232,017 Inventories — 190,253 — — 190,253 Other 89,211 41,455 952 — 131,618 Total current assets 920,006 397,999 229,361 (4,615 ) 1,542,751 Property, plant and equipment, net 10,470 6,442,623 2 363 6,453,458 Investment in subsidiaries 7,464,221 — — (7,464,221 ) — Intercompany receivables 2,021,110 — (2,021,110 ) — Note receivable from Arch Western 675,000 — — (675,000 ) — Other 131,884 300,058 1,572 — 433,514 Total assets $ 9,201,581 $ 9,161,790 $ 230,935 $ (10,164,583 ) $ 8,429,723 Liabilities and Stockholders’ Equity Accounts payable $ 23,394 $ 156,664 $ 55 $ — $ 180,113 Accrued expenses and other current liabilities 85,899 220,017 1,095 (4,615 ) 302,396 Current maturities of debt 27,625 9,260 — — 36,885 Total current liabilities 136,918 385,941 1,150 (4,615 ) 519,394 Long-term debt 5,084,839 38,646 — 5,123,485 Intercompany payables 1,817,755 — 203,355 (2,021,110 ) — Note payable to Arch Coal — 675,000 — (675,000 ) — Asset retirement obligations 981 397,915 — — 398,896 Accrued pension benefits 5,967 10,293 — — 16,260 Accrued postretirement benefits other than pension 4,430 28,238 — — 32,668 Accrued workers’ compensation 9,172 85,119 — — 94,291 Deferred income taxes 422,809 — — — 422,809 Other noncurrent liabilities 50,919 102,461 386 — 153,766 Total liabilities 7,533,790 1,723,613 204,891 (2,700,725 ) 6,761,569 Stockholders’ equity 1,667,791 7,438,177 26,044 (7,463,858 ) 1,668,154 Total liabilities and stockholders’ equity $ 9,201,581 $ 9,161,790 $ 230,935 $ (10,164,583 ) $ 8,429,723 Condensed Consolidating Statements of Cash Flows Year Ended December 31, 2015 Parent/Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated (In thousands) Cash provided by (used in) operating activities $ (445,136 ) $ 314,535 $ 86,234 $ — $ (44,367 ) Investing Activities Capital expenditures (1,108 ) (117,916 ) — — (119,024 ) Additions to prepaid royalties — (5,871 ) — — (5,871 ) Proceeds from disposals and divestitures — 2,191 — — 2,191 Purchases of short term investments (246,735 ) — — — (246,735 ) Proceeds from sales of short term investments 290,205 — — — 290,205 Proceeds from sales of equity investments and securities — 2,259 — — 2,259 Withdrawals (deposits) of restricted cash — — (91,864 ) — (91,864 ) Investments in and advances to affiliates (913 ) (10,589 ) — — (11,502 ) Cash provided by (used in) investing activities 41,449 (129,926 ) (91,864 ) — (180,341 ) Financing Activities Payments on term loan (19,500 ) — — — (19,500 ) Net payments on other debt (2,692 ) (8,640 ) — — (11,332 ) Expenses related to debt restructuring (27,910 ) — — — (27,910 ) Transactions with affiliates, net 219,250 (225,899 ) 6,649 — — Cash provided by (used in) financing activities 169,148 (234,539 ) 6,649 — (58,742 ) Increase (decrease) in cash and cash equivalents (234,539 ) (49,930 ) 1,019 — (283,450 ) Cash and cash equivalents, beginning of period 572,185 150,358 11,688 — 734,231 Cash and cash equivalents, end of period $ 337,646 $ 100,428 $ 12,707 $ — $ 450,781 Condensed Consolidating Statements of Cash Flows Year Ended December 31, 2014 Parent/Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated (In thousands) Cash provided by (used in) operating activities $ (324,688 ) $ 305,048 $ (13,942 ) $ — $ (33,582 ) Investing Activities Capital expenditures (2,700 ) (144,586 ) — — (147,286 ) Additions to prepaid royalties — (7,317 ) — — (7,317 ) Proceeds from disposals and divestitures 57,625 4,733 — — 62,358 Purchases of short term investments (211,929 ) — — — (211,929 ) Proceeds from sales of short term investments 205,611 — — — 205,611 Proceeds from sales of investments in equity securities 9,464 — — — 9,464 Withdrawals (deposits) of restricted cash — — (5,678 ) — (5,678 ) Investments in and advances to affiliates (2,541 ) (14,116 ) — — (16,657 ) Cash provided by (used in) investing activities 55,530 (161,286 ) (5,678 ) — (111,434 ) Financing Activities Payments on term loan (19,500 ) — — — (19,500 ) Net payments on other debt (1,258 ) (4,437 ) — — (5,695 ) Debt financing costs (2,219 ) — (2,300 ) — (4,519 ) Dividends paid (2,123 ) — — — (2,123 ) Other (15 ) — — — (15 ) Transactions with affiliates, net 67,125 (89,385 ) 22,260 — — Cash provided by (used in) financing activities 42,010 (93,822 ) 19,960 — (31,852 ) Increase (decrease) in cash and cash equivalents (227,148 ) 49,940 340 — (176,868 ) Cash and cash equivalents, beginning of period 799,333 100,418 11,348 — 911,099 Cash and cash equivalents, end of period $ 572,185 $ 150,358 $ 11,688 $ — $ 734,231 Condensed Consolidating Statements of Cash Flows Year Ended December 31, 2013 Parent/Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated (In thousands) Cash provided by (used in) operating activities $ (632,060 ) $ 637,193 $ 50,609 $ — $ 55,742 Investing Activities Capital expenditures (3,320 ) (293,664 ) — — (296,984 ) Proceeds from disposals and divestitures — 433,453 — — 433,453 Proceeds from sales-leaseback transaction — 34,919 — — 34,919 Investments in and advances to affiliates (5,451 ) (10,321 ) — 512 (15,260 ) Purchases of short term investments (213,726 ) — — — (213,726 ) Proceeds from sales of short term investments 194,537 — — — 194,537 Additions to prepaid royalties — (14,947 ) — — (14,947 ) Change in restricted cash 3,453 — — — 3,453 Cash provided by (used in) investing activities (24,507 ) 149,440 — 512 125,445 Financing Activities Contributions from parent — 512 — (512 ) — Proceeds from term loan and senior notes 644,000 — — — 644,000 Payments to retire debt (628,660 ) — — — (628,660 ) Payments on term loan (17,250 ) — — — (17,250 ) Net payments on other debt (6,324 ) (512 ) — — (6,836 ) Debt financing costs (19,864 ) — (625 ) — (20,489 ) Dividends paid (25,475 ) — — — (25,475 ) Transactions with affiliates, net 838,160 (786,683 ) (51,477 ) — — Cash provided by (used in) financing activities 784,587 (786,683 ) (52,102 ) (512 ) (54,710 ) Increase in cash and cash equivalents 128,020 (50 ) (1,493 ) — 126,477 Cash and cash equivalents, beginning of period 671,313 100,468 12,841 — 784,622 Cash and cash equivalents, end of period $ 799,333 $ 100,418 $ 11,348 $ — $ 911,099

Valuation and Qualifying Accoun

Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2015
Valuation and Qualifying Accounts [Abstract]
Valuation and Qualifying Accounts	Valuation and Qualifying Accounts Additions (Reductions) Balance at Charged to Charged to Balance at Beginning of Costs and Other End of Year Expenses Accounts Deductions (a) Year (In thousands) Year ended December 31, 2015 Reserves deducted from asset accounts: Accounts receivable and other receivables $ 159 $ 7,683 $ — $ — $ 7,842 Current assets — supplies and inventory 6,625 431 — (b) 1,065 5,991 Deferred income taxes 270,251 860,847 — — 1,131,098 Year ended December 31, 2014 Reserves deducted from asset accounts: Accounts receivable and other receivables $ 775 $ — $ — $ 616 $ 159 Current assets — supplies and inventory 8,446 580 (76 ) (b) 2,325 6,625 Deferred income taxes 43,322 226,929 — — 270,251 Year ended December 31, 2013 Reserves deducted from asset accounts: Accounts receivable and other receivables $ 1,043 $ 346 $ — $ 614 $ 775 Current assets — supplies and inventory 12,589 503 (2,274 ) 2,372 $ 8,446 Deferred income taxes 34,663 8,659 — — $ 43,322 (a) Reserves utilized, unless otherwise indicated. (b) Disposition of subsidiaries

Accounting Policies (Policies)

Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Consolidation Policy	The accompanying consolidated financial statements include the accounts of Arch Coal, Inc. and its subsidiaries and controlled entities (the “Company”). The Company’s primary business is the production of thermal and metallurgical coal from surface and underground mines located throughout the United States, for sale to utility, industrial and steel producers both in the United States and around the world. The Company currently operates mining complexes in West Virginia, Kentucky, Maryland, Virginia, Illinois, Wyoming and Colorado. All subsidiaries are wholly-owned. Intercompany transactions and accounts have been eliminated in consolidation.
Accounting Pronouncements	Accounting Pronouncements There are no accounting pronouncements whose adoption had, or is expected to have, a material impact on the Company's consolidated financial statements.
Accounting Estimates	Accounting Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and revenues and expenses in the accompanying consolidated financial statements and the disclosure of contingent assets and liabilities. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents are stated at cost. Cash equivalents consist of highly-liquid investments with an original maturity of three months or less when purchased.
Restricted cash	Restricted cash Restricted cash represents cash collateral supporting letters of credit issued under the Company's accounts receivable securitization program.
Accounts Receivable	Accounts Receivable Accounts receivable are recorded at amounts that are expected to be collected, based on past collection history, the economic environment and specified risks identified in the receivables portfolio.
Inventories	Inventories Coal and supplies inventories are valued at the lower of average cost or market. Coal inventory costs include labor, supplies, equipment costs, transportation costs incurred prior to the transfer of title to customers and operating overhead. The costs of removing overburden, called stripping costs, incurred during the production phase of the mine are considered variable production costs and are included in the cost of the coal extracted during the period the stripping costs are incurred.
Investments and Membership Interests in Joint Ventures	Investments and Membership Interests in Joint Ventures Investments and membership interests in joint ventures are accounted for under the equity method of accounting if the Company has the ability to exercise significant influence, but not control, over the entity. The Company's share of the entity's income or loss is reflected in " Other operating expense (income), net " in the consolidated statements of operations. Information about investment activity is provided in Note 10 , " Equity Method Investments and Membership Interests in Joint Ventures ". Investments in debt securities and marketable equity securities that do not qualify for equity method accounting are classified as available-for-sale and are recorded at their fair values. Unrealized gains and losses on these investments are recorded in other comprehensive income or loss. A decline in the value of an investment that is considered other-than-temporary would be recognized in operating expenses.
Acquired Sales Contracts	Acquired Sales Contracts Coal supply agreements (sales contracts) acquired in a business combination are capitalized at their fair value and amortized over the tons of coal shipped during the term of the contract. The fair value of a sales contract is determined by discounting the cash flows attributable to the difference between the contract price and the prevailing forward prices for the tons under contract at the date of acquisition. See Note 11 , " Acquired Sales Contracts " for further information related to the Company's acquired sales contracts.
Exploration Costs	Exploration Costs Costs to acquire permits for exploration activities are capitalized. Drilling and other costs related to locating coal deposits and evaluating the economic viability of such deposits are expensed as incurred.
Prepaid Royalties	Prepaid Royalties Leased mineral rights are often acquired through royalty payments. When royalty payments represent prepayments recoupable against royalties owed on future revenues from the underlying coal, they are recorded as a prepaid asset, with amounts expected to be recouped within one year classified as current. When coal from these leases is sold, the royalties owed are recouped against the prepayment and charged to cost of sales. An impairment charge is recognized for prepaid royalties that are not expected to be recouped.
Property, Plant and Equipment	Property, Plant and Equipment Plant and Equipment Plant and equipment are recorded at cost. Interest costs incurred during the construction period for major asset additions are capitalized. We did not capitalize any interest costs during the years ended December 31, 2015 and 2014 respectively. Expenditures that extend the useful lives of existing plant and equipment or increase the productivity of the asset are capitalized. The cost of maintenance and repairs that do not extend the useful life or increase the productivity of the asset is expensed as incurred. Preparation plants and loadouts are depreciated using the units-of-production method over the estimated recoverable reserves, subject to a minimum level of depreciation. Other plant and equipment are depreciated principally using the straight-line method over the estimated useful lives of the assets, limited by the remaining life of the mine. The useful lives of mining equipment, including longwalls, draglines and shovels, range from 5 to 32 years. The useful lives of buildings and leasehold improvements generally range from 10 to 30 years. Deferred Mine Development Costs of developing new mines or significantly expanding the capacity of existing mines are capitalized and amortized using the units-of-production method over the estimated recoverable reserves that are associated with the property being benefited. Costs may include construction permits and licenses; mine design; construction of access roads, shafts, slopes and main entries; and removing overburden to access reserves in a new pit. Additionally, deferred mine development includes the asset cost associated with asset retirement obligations. Coal Lands and Mineral Rights Rights to coal reserves may be acquired directly through governmental or private entities. A significant portion of the Company's coal reserves are controlled through leasing arrangements. Lease agreements are generally long-term in nature (original terms range from 10 to 50 years), and substantially all of the leases contain provisions that allow for automatic extension of the lease term providing certain requirements are met. The net book value of the Company's coal interests was $2.4 billion and $4.7 billion at December 31, 2015 and 2014 , respectively. Payments to acquire royalty lease agreements and lease bonus payments are capitalized as a cost of the underlying mineral reserves and depleted over the life of proven and probable reserves. Coal lease rights are depleted using the units-of-production method, and the rights are assumed to have no residual value. Future lease bonus payments total $60.0 million in 2016 . Depreciation, depletion and amortization. The depreciation, depletion and amortization related to long-lived assets is reflected in the statement of operations as a separate line item. No depreciation, depletion or amortization is included in any other operating cost categories. Impairment If facts and circumstances suggest that the carrying value of a long-lived asset or asset group may not be recoverable, the asset or asset group is reviewed for potential impairment. If this review indicates that the carrying amount of the asset will not be recoverable through projected undiscounted cash flows generated by the asset and its related asset group over its remaining life, then an impairment loss is recognized by reducing the carrying value of the asset to its fair value. The Company may, under certain circumstances, idle mining operations in response to market conditions or other factors. Because an idling is not a permanent closure, it is not considered an automatic indicator of impairment. See additional discussion in Note 5 , " Impairment Charges and Mine Closure Costs ."
Goodwill	Goodwill In a business combination, goodwill represents the excess of the purchase price over the fair value assigned to the net tangible and identifiable intangible assets acquired. The Company tests goodwill for impairment annually as of the beginning of the fourth quarter, or when circumstances indicate a possible impairment may exist. If the results of the testing indicate that the carrying amount of a reporting unit exceeds the fair value of the reporting unit, the fair value of goodwill must be calculated. An impairment loss generally would be recognized when the carrying amount of goodwill exceeds the implied fair value of goodwill, determined by subtracting the fair value of the other assets and liabilities associated with the reporting unit from the total fair value of the reporting unit. The fair value of a reporting unit is determined using a discounted cash flow ("DCF") technique. A number of significant assumptions and estimates are involved in the application of the DCF analysis to forecast operating cash flows, including the discount rate, projections of production volumes, quality and costs to produce; projections of sales volumes by market (e.g., thermal versus metallurgical); and projections of market prices. See additional discussion in Note 6 , " Goodwill ."
Deferred Financing Costs	Deferred Financing Costs The Company capitalizes costs incurred in connection with new borrowings, the establishment or enhancement of credit facilities and the 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 interest method. The unamortized balance of deferred financing costs was $112.9 million and $89.1 million at December 31, 2015 and 2014 , respectively.
Revenue Recognition	Revenue Recognition Revenues include sales to customers of coal produced at Company operations and coal purchased from third parties. The Company recognizes revenue at the time risk of loss passes to the customer at contracted amounts. Transportation costs are included in cost of sales and amounts billed by the Company to its customers for transportation are included in revenues.
Other Operating Expense (Income), net	Other Operating Expense (Income), net Other operating expense (income), net in the accompanying consolidated statements of operations reflects income and expense from sources other than physical coal sales, including: bookouts, or the practice of offsetting purchase and sale contracts for shipping convenience purposes; contract settlements; liquidated damage charges related to unused terminal and port capacity; royalties earned from properties leased to third parties; income from equity investments (Note 10 ); gains and losses from divestitures and dispositions of assets (Note 3 ); and realized gains and losses on derivatives that do not qualify for hedge accounting and are not held for trading purposes (Note 12 ).
Asset Retirement Obligations	Asset Retirement Obligations The Company's legal obligations associated with the retirement of long-lived assets are recognized at fair value at the time the obligations are incurred. Accretion expense is recognized through the expected settlement date of the obligation. Obligations are incurred at the time development of a mine commences for underground and surface mines or construction begins for support facilities, refuse areas and slurry ponds. The obligation's fair value is determined using a discounted cash flow technique and is based upon permit requirements and various estimates and assumptions that would be used by market participants, including estimates of disturbed acreage, reclamation costs and assumptions regarding equipment productivity. Upon initial recognition of a liability, a corresponding amount is capitalized as part of the carrying value of the related long-lived asset. The Company reviews its asset retirement obligation at least annually and makes necessary adjustments for permit changes as granted by state authorities and for revisions of estimates of the amount and timing of costs. For ongoing operations, adjustments to the liability result in an adjustment to the corresponding asset. For idle operations, adjustments to the liability are recognized as income or expense in the period the adjustment is recorded. Any difference between the recorded obligation and the actual cost of reclamation is recorded in profit or loss in the period the obligation is settled. See additional discussion in Note 16 , " Asset Retirement Obligations ."
Loss Contingencies	Loss Contingencies The Company accrues for cost related to contingencies when a loss is probable and the amount is reasonably determinable. Disclosure of contingencies is included in the financial statements when it is at least reasonably possible that a material loss or an additional material loss in excess of amounts already accrued may be incurred. The amount accrued represents the Company's best estimate of the loss, or, if no best estimate within a range of outcomes exists, the minimum amount in the range.
Derivative Instruments	Derivative Instruments The Company generally utilizes derivative instruments to manage exposures to commodity prices. Additionally, the Company may hold certain coal derivative instruments for trading purposes. Derivative financial instruments are recognized in the balance sheet at fair value. Certain coal contracts may meet the definition of a derivative instrument, but because they provide for the physical purchase or sale of coal in quantities expected to be used or sold by the Company over a reasonable period in the normal course of business, they are not recognized on the balance sheet. Certain derivative instruments are designated as the hedge instrument in a hedging relationship. In a fair value hedge, the Company hedges the risk of changes in the fair value of a firm commitment, typically a fixed-price coal sales contract. Changes in both the hedged firm commitment and the fair value of a derivative used as a hedge instrument in a fair value hedge are recorded in earnings. In a cash flow hedge, the Company hedges the risk of changes in future cash flows related to a forecasted purchase or sale. Changes in the fair value of the derivative instrument used as a hedge instrument in a cash flow hedge are recorded in other comprehensive income or loss. Amounts in other comprehensive income or loss are reclassified to earnings when the hedged transaction affects earnings and are classified in a manner consistent with the transaction being hedged. The Company formally documents the relationships between hedging instruments and the respective hedged items, as well as its risk management objectives for hedge transactions. The Company evaluates the effectiveness of its hedging relationships both at the hedge's inception and on an ongoing basis. Any ineffective portion of the change in fair value of a derivative instrument used as a hedge instrument in a fair value or cash flow hedge is recognized immediately in earnings. The ineffective portion is based on the extent to which exact offset is not achieved between the change in fair value of the hedge instrument and the cumulative change in expected future cash flows on the hedged transaction from inception of the hedge in a cash flow hedge or the change in the fair value. Ineffectiveness was insignificant for the years ended December 31, 2015, 2014 and 2013. See Note 12 , "Derivatives" for further disclosures related to the Company's derivative instruments.
Fair Value	Fair Value Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly hypothetical 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. See Note 17 , "Fair Value Measurements" for further disclosures related to the Company's recurring fair value estimates.
Income Taxes	Income Taxes Deferred income taxes are provided for temporary differences arising from differences between the financial statement 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 that a deferred tax asset will not be realized. Management reassesses the ability to realize its deferred tax assets annually in the fourth quarter or when circumstances indicate that the ability to realize deferred tax assets has changed. In determining the need for a valuation allowance, the Company considers projected realization of tax benefits based on expected levels of future taxable income, available tax planning strategies and the reversal of temporary differences. Benefits from tax positions that are uncertain are not recognized unless the Company concludes that it is more likely than not that the position would be sustained in a dispute with taxing authorities, should the dispute be taken to the court of last resort. The Company would measure any such benefit at the largest amount of benefit that is greater than 50 percent likely of being realized upon settlement with taxing authorities. See Note 15 , "Taxes" for further disclosures about income taxes.
Benefit Plans	Benefit Plans The Company has non-contributory defined benefit pension plans covering most of its salaried and hourly employees. On January 1, 2015 the Company's cash balance and excess pension plans were amended to freeze new service credits for any new or active employee. The Company also currently provides certain postretirement medical and life insurance coverage for eligible employees. The cost of providing these benefits are determined on an actuarial basis and accrued over the employee's period of active service. The Company recognizes the overfunded or underfunded status of these plans as determined on an actuarial basis on the balance sheet and the changes in the funded status are recognized in other comprehensive income. See Note 21 , " Employee Benefit Plans " for additional disclosures relating to these obligations.
Stock-Based Compensation	Stock-Based Compensation The compensation cost of all stock-based awards is determined based on the grant-date fair value of the award, and is recognized over the requisite service period. The grant-date fair value of option awards is determined using a Black-Scholes option pricing model. Compensation cost for an award with performance conditions is accrued if it is probable that the conditions will be met. See further discussion in Note 19 , " Stock-Based Compensation and Other Incentive Plans ."
Accounting Standards Issued	Accounting Standards Issued In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers. ASU 2014-09 is a comprehensive revenue recognition standard that will supersede nearly all existing revenue recognition guidance under current U.S. GAAP and replace it with a principle based approach for determining revenue recognition. ASU 2014-09 will require that companies recognize revenue based on the value of transferred goods or services as they occur in the contract. The ASU also will require 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 obtain or fulfill a contract. ASU 2014-09 is effective for interim and annual periods beginning after December 15, 2017. Early adoption is permitted only in annual reporting periods beginning after December 15, 2016, including interim periods therein. Entities will be able to transition to the standard either retrospectively or as a cumulative-effect adjustment as of the date of adoption. The Company is in the process of evaluating the impact of ASU 2014-09 on the Company’s financial statements and disclosures. 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." ASU 2014-15 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 update provides guidance to an organization's management, with principles and definitions that are intended to reduce diversity in the timing and content of disclosures that are commonly provided by organizations today in the financial statement footnotes. The amendments are effective for the Company's fiscal year and interim periods within those years beginning after November 1, 2017. Early application is permitted. The Company is in the process of evaluating the impact of ASU 2014-15 on the Company’s financial statements and disclosures. In April 2015, the Financial Accounting Standards Board ("FASB") issued the Accounting Standards Update No. 2015-03 ("ASU 2015-03"), Simplifying the Presentation of Debt Issuance Costs. ASU 2015-03 requires debt issuance costs related to recognized debt liability to be presented in the balance sheet as a direct deduction from the carrying amount of the liability, consistent with debt discounts. Amendments in the update are effective retrospectively for fiscal years and interim periods within those years, beginning after December 15, 2015, with early adoption permitted. Upon adoption of this guidance, the current financial statement classification of debt issuance costs will change from total assets to long-term debt on our Consolidated Balance Sheets. In August 2015, the FASB issued ASU 2015-15, " Interest - Imputation of Interest (Subtopic 835-30) - Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements ". On April 7, 2015, the FASB issued ASU 2015-03, Interest-Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs, which requires entities to present debt issuance costs related to a recognized debt liability as a direct deduction from the carrying amount of that debt liability. Given the absence of authoritative guidance within ASU 2015-03 for debt issuance costs related to line-of-credit arrangements, the SEC staff stated that they would not object to an entity deferring and presenting debt issuance costs as an asset and subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. ASU 2015-15 adds these SEC comments to the "S" section of the Codification. The adoption of this standard is not expected to have a material impact on the Company's consolidated financial statements. In May 2015, the FASB issued ASU No. 2015-07 “Fair Value Measurement (Topic 820), Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or its Equivalent)” . This ASU eliminates the requirement to categorize within the fair value hierarchy investments who fair values are measured at net asset value (NAV) using the practical expedient in ASC 820. Instead entities will have to disclose the fair values of such investments so that financial statement users can reconcile amounts reported in the fair value hierarchy table to the amounts reported in the balance sheet. ASU 2015-07 is effective for public business entities in fiscal years beginning after 15 December 2015 and interim periods within those years. Early adoption is permitted and guidance will be applied retrospectively. The Company is currently evaluating the impact the adoption of ASU 2015-07 on the Company’s financial statements and disclosures. In July 2015, the FASB issued Accounting Standards Update 2015-11, Simplifying the Measurement of Inventory, which requires that inventory within the scope of ASU 2015-11 be measured at the lower of cost and net realizable value. Inventory measured using last-in, first-out (LIFO) and the retail inventory method are not impacted by the new guidance. ASU 2015-11 applies to all other inventory, which includes inventory that is measured using first-in, first-out (FIFO) or average cost. An entity should measure inventory within the scope of ASU 2015-11 at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. ASU 2015-11 is effective for public business entities in fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU 2015-11 on the Company’s financial statements and disclosures. On November 20, 2015, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2015-17, Balance Sheet Classification of Deferred Taxes, requiring all deferred tax assets and liabilities, and any related valuation allowance, to be classified as noncurrent on the balance sheet. The classification change for all deferred taxes as noncurrent simplifies entities’ processes as it eliminates the need to separately identify the net current and net noncurrent deferred tax asset or liability in each jurisdiction and allocate valuation allowances. The Company is in the process of evaluating the impact of ASU 2015-07 on the Company’s financial statements and disclosures.

Divestitures (Tables)

Divestitures (Tables)	12 Months Ended
	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	The following table summarizes the results of discontinued operations through the date of disposition: Year Ended December 31, 2013 Total Revenues $ 219,002 Income from discontinued operations before income taxes $ 32,167 Gain on sale 120,321 Less: income tax expense 49,092 Income from discontinued operations, including gain on sale - net of tax $ 103,396 Basic earnings per common share from discontinued operations $ 4.87 Diluted earnings per common share from discontinued operations $ 4.87

Accumulated Other Comprehensi41

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following items are included in accumulated other comprehensive income (loss): Pension, Postretirement Accumulated and Other Post- Other Derivative Employment Available-for- Comprehensive Instruments Benefits Sale Securities Income (Loss) (In thousands) Balance at January 1, 2014 $ 565 $ 31,112 $ 6,015 $ 37,692 Unrealized gains 3,677 (22,516 ) (5,727 ) (24,566 ) Amounts reclassified from accumulated other comprehensive income (loss) (1,692 ) (5,736 ) (2,457 ) (9,885 ) Balance at December 31, 2014 2,550 2,860 (2,169 ) 3,241 Unrealized gains (losses) 3,903 (8,723 ) (3,333 ) (8,153 ) Amounts reclassified from accumulated other comprehensive income (loss) (6,128 ) 5,142 4,083 3,097 Balance at December 31, 2015 $ 325 $ (721 ) $ (1,419 ) $ (1,815 )
Schedule of comprehensive income reclassifications	The following amounts were reclassified out of accumulated other comprehensive income (loss) during the years ended December 31, 2015 and 2014 , respectively: Details about accumulated other comprehensive income components Reclassifications Line Item in the Consolidated Statement of Operations 2015 2014 (in thousands) Derivative instruments $ 9,575 $ 2,643 Revenues (3,447 ) (951 ) Provision for (benefit from) income taxes $ 6,128 $ 1,692 Net of tax Pension, postretirement and other post-employment benefits Amortization of prior service credits $ 8,335 1 $ 11,760 Amortization of net actuarial gains (losses) (16,369 ) 1 (2,797 ) (8,034 ) 8,963 Total before tax 2,892 (3,227 ) Provision for (benefit from) income taxes $ (5,142 ) $ 5,736 Net of tax Available-for-sale securities $ (6,391 ) 2 $ 3,838 Interest and investment income 2,308 (1,381 ) Provision for (benefit from) income taxes $ (4,083 ) $ 2,457 Net of tax 1 Production-related benefits and workers' compensation costs are included in costs to produce coal. 2 The gains and losses on sales of available-for-sale-securities are determined on a specific identification basis.

Impairment Charges and Mine C42

Impairment Charges and Mine Closure Costs (Tables)	12 Months Ended
	Dec. 31, 2015
Impairment Charges and Mine Closure Costs [Abstract]
Restructuring and Related Costs	The following table summarizes the amounts reflected on the line " Asset impairment and mine closure costs " in the consolidated statements of operations: Year Ended December 31, Description 2015 2014 2013 (In thousands) Coal lands and mineral rights $ 2,210,488 $ — $ 79,094 Plant and equipment 199,107 1,512 36,296 Deferred development 159,474 — 13,451 Prepaid royalties 41,990 15,356 1,104 Equity investments 21,325 — 28,947 Notes receivable — — 49,203 Inventories 66 — 12,765 Other (4,147 ) 7,245 19 Total $ 2,628,303 $ 24,113 $ 220,879

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	Changes in the carrying value of goodwill for the three years ended December 31, 2015 are as follows: (In thousands) Balance at January 1, 2013 $ 265,423 Impairment (265,423 ) Balance at December 31, 2013 $ —

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2015
Inventory Disclosure [Abstract]
Inventories	Inventories consist of the following: December 31, 2015 2014 (In thousands) Coal $ 85,043 $ 71,901 Repair parts and supplies 111,677 118,352 $ 196,720 $ 190,253

Investments in Available-for-45

Investments in Available-for-Sale Securities (Tables)	12 Months Ended
	Dec. 31, 2015
Available-for-sale Securities [Abstract]
Available-for-sale Securities	The Company's investments in available-for-sale marketable securities are as follows: December 31, 2015 Balance Sheet Gross Gross Classification Unrealized Unrealized Fair Short-Term Other Cost Basis Gains Losses Value Investments Assets (In thousands) Available-for-sale: U.S. government and agency securities $ 10,007 $ — $ (12 ) $ 9,995 $ 9,995 Corporate notes and bonds 190,496 — (299 ) 190,197 190,197 — Equity securities 3,938 668 (2,888 ) 1,718 — 1,718 Total Investments $ 204,441 $ 668 $ (3,199 ) $ 201,910 $ 200,192 $ 1,718 December 31, 2014 Balance Sheet Gross Gross Classification Unrealized Unrealized Fair Short-Term Other Cost Basis Gains Losses Value Investments Assets (In thousands) Available-for-sale: Corporate notes and bonds $ 253,590 $ — $ (4,636 ) $ 248,954 $ 248,954 $ — Equity securities 3,910 4,125 (2,890 ) 5,145 — 5,145 Total Investments $ 257,500 $ 4,125 $ (7,526 ) $ 254,099 $ 248,954 $ 5,145

Equity Method Investments and46

Equity Method Investments and Membership Interests in Joint Ventures (Tables)	12 Months Ended
	Dec. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Schedule Of Equity Method Investments	Below are the equity method investments reflected in the consolidated balance sheets: Investee Knight Hawk DTA Millennium Tongue River DKRW Tenaska Other Total Balance at January 1, 2013 $ 149,063 $ 15,462 $ 32,214 $ 14,697 $ 15,515 $ 15,264 $ — $ 242,215 Advances to (distributions from) affiliates, net (13,536 ) 3,644 6,476 4,004 — — 200 788 Equity in comprehensive income (loss) 17,279 (4,969 ) (2,796 ) (282 ) (1,832 ) — — 7,400 Impairment of equity investment — — — — (13,683 ) (15,264 ) — (28,947 ) Balance at December 31, 2013 152,806 14,137 35,894 18,419 — — 200 221,456 Advances to (distributions from) affiliates, net (12,603 ) 3,774 6,742 2,541 — — 3,600 4,054 Equity in comprehensive income (loss) 18,274 (4,173 ) (2,413 ) (220 ) — — (1,136 ) 10,332 Balance at December 31, 2014 158,477 13,738 40,223 20,740 — — 2,664 235,842 Advances to (distributions from) affiliates, net (29,862 ) 3,207 7,052 913 — — 330 (18,360 ) Equity in comprehensive income (loss) 22,977 (3,706 ) (9,686 ) (328 ) — — (1,278 ) 7,979 Impairment of equity investment — — — (21,325 ) — — — (21,325 ) Sale of equity investment — — — — — — (2,259 ) $ (2,259 ) Balance at December 31, 2015 $ 151,592 $ 13,239 $ 37,589 $ — $ — $ — $ (543 ) $ 201,877

Acquired Sales Contracts (Table

Acquired Sales Contracts (Tables)	12 Months Ended
	Dec. 31, 2015
Acquired Sales Contracts [Abstract]
Schedule of Acquired Sales Contracts	The acquired sales contracts reflected in the consolidated balance sheets are as follows: December 31, 2015 December 31, 2014 Assets Liabilities Net Total Assets Liabilities Net Total (In thousands) (In thousands) Acquired fair value $ 131,299 $ 166,697 $ 131,299 $ 166,697 Accumulated amortization (130,839 ) (151,354 ) (130,363 ) (134,988 ) Total $ 460 $ 15,343 $ (14,883 ) $ 936 $ 31,709 $ (30,773 ) Balance Sheet classification: Other current $ 460 $ 3,852 $ 462 $ 12,453 Other noncurrent $ — $ 11,491 $ 474 $ 19,256

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Price Risk Derivatives	At December 31, 2015 , the Company held derivatives for risk management purposes that are expected to settle in the following years: (Tons in thousands) 2016 2017 Total Coal sales 480 — 480 Coal purchases 255 — 255
Disclosure Of Fair Value Of Derivatives	The fair value and location of derivatives reflected in the accompanying consolidated balance sheets are as follows: December 31, 2015 December 31, 2014 Fair Value of Derivatives Asset Liability Asset Liability (In thousands) Derivative Derivative Derivative Derivative Derivatives Designated as Hedging Instruments Coal $ 4 $ (20 ) $ 6,535 $ (2,492 ) Derivatives Not Designated as Hedging Instruments Heating oil -- diesel purchases 1,017 — 300 — Coal held for trading purposes, exchange traded swaps and futures 110,653 (104,814 ) 96,898 (93,272 ) Coal -- risk management 3,912 (1,947 ) 8,510 (3,688 ) Natural gas 494 (247 ) — — Total 116,076 (107,008 ) 105,708 (96,960 ) Total derivatives 116,080 (107,028 ) 112,243 (99,452 ) Effect of counterparty netting (107,028 ) 107,028 (98,686 ) 98,686 Net derivatives as classified in the balance sheets $ 9,052 $ — $ 9,052 $ 13,557 $ (766 ) $ 12,791 December 31, 2015 2014 Net derivatives as reflected on the balance sheets Heating oil Other current assets $ 1,017 $ 300 Coal Coal derivative assets 8,035 13,257 Accrued expenses and other current liabilities — (766 ) $ 9,052 $ 12,791
Effects Of Derivatives On Measures Of Financial Performance	The effects of derivatives on measures of financial performance are as follows: Derivatives used in Cash Flow Hedging Relationships (in thousands) For the year ended December 31, Gain (Loss) Recognized in Other Comprehensive Income (Effective Portion) Gains (Losses) Reclassified from Other Comprehensive Income into Income 2015 2014 2013 2015 2014 2013 Coal sales (1) $ 12,816 $ 10,842 (338 ) $ 18,635 $ 5,336 $ 3,664 Coal purchases (2) (6,718 ) (5,097 ) 526 (9,060 ) (2,693 ) (683 ) $ 6,098 $ 5,745 $ 188 $ 9,575 $ 2,643 $ 2,981 No ineffectiveness or amounts excluded from effectiveness testing relating to the Company’s cash flow hedging relationships were recognized in the results of operations in the years ended December 31, 2015 , 2014 and 2013 . Derivatives Not Designated as Hedging Instruments (in thousands) For the year ended December 31, Gain (Loss) Recognized 2015 2014 2013 Coal — unrealized (3) $ (3,883 ) $ 430 $ (12,700 ) Coal — realized (4) $ 3,236 $ 5,956 $ 32,534 Heating oil — diesel purchases (4) $ (8,294 ) $ (7,848 ) $ (9,791 ) Heating oil — fuel surcharges (4) $ — $ (405 ) $ (947 ) Natural gas $ 878 $ — $ — Foreign currency $ (887 ) $ — $ — Location in statement of operations: (1) — Revenues (2) — Cost of sales (3) — Change in fair value of coal derivatives and coal trading activities, net (4) — Other operating income, net

Accrued Expenses and Other Cu49

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
Accrued Expenses and Other Current Liabilities [Abstract]
Schedule of Accrued Liabilities	Accrued expenses and other current liabilities consist of the following: December 31, 2015 2014 (In thousands) Payroll and employee benefits $ 58,423 $ 73,362 Taxes other than income taxes 104,755 114,598 Interest 119,785 30,384 Acquired sales contracts 3,852 12,453 Workers’ compensation 16,875 16,714 Asset retirement obligations 13,795 19,222 Other 11,965 35,663 $ 329,450 $ 302,396

Debt and Financing Arrangemen50

Debt and Financing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Debt	December 31, 2015 2014 (In thousands) Term loan due 2018 ($1.9 billion and $1.93 billion face value, respectively) $ 1,875,429 $ 1,890,846 7.00% senior notes due 2019 at par 1,000,000 1,000,000 8.00% senior secured notes due 2019 at par 350,000 350,000 9.875% senior notes ($375.0 million face value) due 2019 365,600 363,493 7.25% senior notes due 2020 at par 500,000 500,000 7.25% senior notes due 2021 at par 1,000,000 1,000,000 Other 47,134 56,031 5,138,163 5,160,370 Less current maturities of debt 5,107,210 36,885 Long-term debt $ 30,953 $ 5,123,485
Schedule of Maturities of Long-term Debt	Year 2016 $ 35,674 2017 30,484 2018 1,858,567 2019 1,731,317 2020 501,642 Thereafter 1,000,574 $ 5,158,258

Taxes (Tables)

Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	Significant components of the provision for (benefit from) income taxes are as follows: Year Ended December 31 2015 2014 2013 (In thousands) Current: Federal $ — $ — $ — State 3 25 (647 ) Total current 3 25 (647 ) Deferred: Federal (329,393 ) 18,535 (318,956 ) State (43,990 ) 7,074 (15,895 ) Total deferred (373,383 ) 25,609 (334,851 ) $ (373,380 ) $ 25,634 $ (335,498 )
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of the statutory federal income tax provision (benefit) at the statutory rate to the actual provision for (benefit from) income taxes follows: Year Ended December 31 2015 2014 2013 (In thousands) Income tax provision (benefit) at statutory rate $ (1,150,283 ) $ (186,452 ) $ (378,463 ) Percentage depletion allowance (19,035 ) (12,692 ) (15,796 ) Goodwill — — 70,301 State taxes, net of effect of federal taxes (76,445 ) (3,903 ) (25,265 ) Change in valuation allowance 865,146 226,929 8,659 Other, net 7,237 1,752 5,066 $ (373,380 ) $ 25,634 $ (335,498 )
Schedule of Deferred Tax Assets and Liabilities	Significant components of the Company's deferred tax assets and liabilities that result from carryforwards and temporary differences between the financial statement basis and tax basis of assets and liabilities are summarized as follows: December 31, 2015 2014 (In thousands) Deferred tax assets: Net operating loss carryforwards $ 1,086,332 $ 871,848 Alternative minimum tax credit carryforwards 120,994 127,169 Reclamation and mine closure 121,276 114,430 Goodwill 38,671 50,072 Workers' compensation 42,835 38,924 Share based compensation 22,612 30,283 Acquired sales contracts 17,466 26,833 Retiree benefit plans 16,996 22,913 Contract obligations — 15,693 Advance royalties 18,751 — Losses from disposed operations resulting from Patriot Coal bankruptcy 39,287 — Other, primarily accrued liabilities 45,303 64,503 Gross deferred tax assets 1,570,523 1,362,668 Valuation allowance (1,135,399 ) (270,251 ) Total deferred tax assets 435,124 1,092,417 Deferred tax liabilities: Plant and equipment 389,169 1,354,396 Deferred development 41,047 95,129 Investment in tax partnerships — 7,377 Other 4,706 5,533 Total deferred tax liabilities 434,922 1,462,435 Net deferred (asset) liability (202 ) 370,018
Summary of Income Tax Contingencies	A reconciliation of the beginning and ending amounts of gross unrecognized tax benefits follows: (In thousands) Balance at January 1, 2013 $ 31,150 Additions based on tax positions related to the current year 1,199 Additions for tax positions of prior years 688 Reductions as a result of lapses in the statute of limitations (1,248 ) Balance at December 31, 2013 31,789 Additions based on tax positions related to the current year 2,920 Balance at December 31, 2014 34,709 Additions for tax positions of the current year 4,168 Balance at December 31, 2015 $ 38,877

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2015
Asset Retirement Obligation [Abstract]
Schedule of Change in Asset Retirement Obligation	The following table describes the changes to the Company's asset retirement obligation liability: Year Ended December 31, 2015 2014 (In thousands) Balance at January 1 (including current portion) $ 418,118 $ 427,653 Accretion expense 33,680 32,909 Obligations of divested operations (334 ) (30,684 ) Adjustments to the liability from changes in estimates (28,570 ) 627 Liabilities settled (12,440 ) (12,387 ) Balance at December 31 $ 410,454 $ 418,118 Current portion included in accrued expenses (13,795 ) (19,222 ) Noncurrent liability $ 396,659 $ 398,896

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Summary Of Financial Assets And Liabilities Accounted For At Fair Value	The table below sets forth, by level, the Company’s financial assets and liabilities that are recorded at fair value in the accompanying consolidated balance sheet: Fair Value at December 31, 2015 Total Level 1 Level 2 Level 3 (In thousands) Assets: Investments in marketable securities $ 201,910 $ 11,713 $ 190,197 $ — Derivatives 9,052 5,597 1,023 2,432 Total assets $ 210,962 $ 17,310 $ 191,220 $ 2,432 Liabilities: Derivatives $ — $ — $ — $ — Fair Value at December 31, 2014 Total Level 1 Level 2 Level 3 (In thousands) Assets: Investments in marketable securities $ 254,099 $ 5,145 $ 248,954 $ — Derivatives 13,557 9,026 1,491 3,040 Total assets $ 267,656 $ 14,171 $ 250,445 $ 3,040 Liabilities: Derivatives $ 766 $ — $ 766 $ —
Summary Of Change In The Fair Values Of Financial Instruments Categorized As Level 3	The following table summarizes the change in the fair values of financial instruments categorized as level 3. Year Ended December 31, 2015 2014 (In thousands) Balance, beginning of period $ 3,040 $ 4,946 Realized and unrealized losses recognized in earnings, net (8,602 ) (6,572 ) Included in other comprehensive income (1,341 ) — Purchases 13,541 5,288 Issuances (4,046 ) (622 ) Settlements (160 ) — Ending balance $ 2,432 $ 3,040

Stock-Based Compensation and 54

Stock-Based Compensation and Other Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Share-based Compensation [Abstract]
Schedule of Share-based Compensation, Stock Options, Activity	Information regarding stock option activity under the Incentive Plan follows for the year ended December 31, 2015 : Weighted Average Aggregate Average Common Exercise Intrinsic Remaining Shares Price Value Life (In thousands) (years) Options outstanding at January 1 682 $ 198.41 Canceled (17 ) $ 151.72 Expired (10 ) $ 300.62 Options outstanding at December 31 655 $ 198.15 $ — 4.6 Options exercisable at December 31 488 $ 213.00 — 4.4 Unvested options at December 31 167
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	Weighted average assumptions used in the Black-Scholes option pricing model for granted options follow: Year Ended December 31, 2013 Weighted average grant-date fair value per share of options granted $ 23.70 Assumptions (weighted average): Risk-free interest rate 0.65% Expected dividend yield 2.30% Expected volatility 66.7% Expected life (in years) 4.5
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	Information regarding restricted stock and restricted stock unit activity and weighted average grant-date fair value follows for the year ended December 31, 2015 : Restricted Stock Restricted Stock Units Weighted Average Weighted Average Common Grant-Date Common Grant-Date Shares Fair Value Shares Fair Value (In thousands) (In thousands) Outstanding at January 1 2 $ 134.42 307 $ 60.53 Granted — — 169 12.84 Vested (2 ) 134.42 (66 ) 104.90 Canceled — — (21 ) 35.81 Outstanding at December 31 — — 389 33.69

Workers' Compensation Expense (

Workers' Compensation Expense (Tables)	12 Months Ended
	Dec. 31, 2015
Workers' Compensation Expense [Abstract]
Workers' compensation expense	The following table details the components of workers’ compensation expense: Year Ended December 31, 2015 2014 2013 (In thousands) Total occupational disease $ 15,199 $ 4,432 $ 6,137 Traumatic injury claims and assessments 16,781 19,924 21,089 Total workers’ compensation expense $ 31,980 $ 24,356 $ 27,226
Workers' compensation liabilities	Summarized below is information about the amounts recognized in the accompanying consolidated balance sheets for workers' compensation benefits: December 31, 2015 2014 (In thousands) Occupational disease costs $ 90,836 $ 72,749 Traumatic and other workers' compensation claims 38,309 38,256 Total obligations 129,145 111,005 Less amount included in accrued expenses 16,875 16,714 Noncurrent obligations $ 112,270 $ 94,291

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Pension and Other Postretirement Benefit Expense [Abstract]
Pension Benefit Costs	Summaries of the changes in the benefit obligations, plan assets and funded status of the plans are as follows: Other Postretirement Pension Benefits Benefits 2015 2014 2015 2014 (In thousands) CHANGE IN BENEFIT OBLIGATIONS Benefit obligations at January 1 $ 353,736 $ 355,468 $ 36,098 $ 42,531 Service cost 9 21,478 866 1,649 Interest cost 14,604 17,070 1,904 1,841 Re-entry of former Magnum employees — — 85,843 — Plan amendments — (23 ) — — Curtailments — (25,787 ) — — Benefits paid (61,955 ) (53,974 ) (3,646 ) (3,431 ) Other-primarily actuarial loss (gain) (5,102 ) 39,504 (17,605 ) (6,492 ) Benefit obligations at December 31 $ 301,292 $ 353,736 $ 103,460 $ 36,098 CHANGE IN PLAN ASSETS Value of plan assets at January 1 $ 336,709 $ 347,952 $ — $ — Actual return on plan assets (1,679 ) 36,130 — — Employer contributions 424 6,601 3,646 3,431 Benefits paid (61,955 ) (53,974 ) (3,646 ) (3,431 ) Value of plan assets at December 31 $ 273,499 $ 336,709 $ — $ — Accrued benefit cost $ (27,793 ) $ (17,027 ) $ (103,460 ) $ (36,098 ) ITEMS NOT YET RECOGNIZED AS A COMPONENT OF NET PERIODIC BENEFIT COST Prior service credit (cost) $ — $ — $ 26,944 $ 21,972 Accumulated gain (loss) (16,769 ) (11,332 ) 11,313 9,125 $ (16,769 ) $ (11,332 ) $ 38,257 $ 31,097 BALANCE SHEET AMOUNTS Current liability $ (420 ) $ (767 ) $ (3,650 ) $ (3,430 ) Noncurrent liability $ (27,373 ) $ (16,260 ) $ (99,810 ) $ (32,668 ) $ (27,793 ) $ (17,027 ) $ (103,460 ) $ (36,098 )
Other Postretirement Benefit Costs	The following table details the components of pension and postretirement benefit costs (credits): Pension Benefits Other Postretirement Benefits Year Ended December 31, Year Ended December 31, 2015 2014 2013 2015 2014 2013 (In thousands) Service cost $ 9 $ 21,478 $ 27,065 $ 866 $ 1,649 $ 2,027 Interest cost 14,604 17,070 16,207 1,904 1,841 1,739 Curtailments — (25,368 ) 47 — — (5,444 ) Settlements 2,656 646 — — — — Expected return on plan assets (20,367 ) (23,756 ) (23,761 ) — — — Amortization of prior service credits — (257 ) (204 ) (8,335 ) (10,003 ) (10,621 ) Amortization of other actuarial losses 8,850 3,128 14,616 (2,109 ) (761 ) (252 ) Net benefit cost (credit) $ 5,752 $ (7,059 ) $ 33,970 $ (7,674 ) $ (7,274 ) $ (12,551 )
Schedule of Assumptions Used	The following table provides the weighted average assumptions used to determine the actuarial present value of projected benefit obligations at December 31 of the respective years. Pension Benefits Other Postretirement Benefits 2015 2014 2015 2014 Discount rate 4.59% 4.15% 4.57% 3.91% Rate of compensation increase N/A N/A N/A N/A The following table provides the weighted average assumptions used to determine net periodic benefit cost for the respective years ended December 31. Pension Benefits Other Postretirement Benefits 2015 2014 2013 2015 2014 2013 Discount rate 4.15% 5.08/ 4.23/ 4.14% 4.13/ 5.05% 3.91% 4.58% 3.64/ 4.58% Rate of compensation increase N/A N/A 3.39% N/A N/A N/A N/A Expected return on plan assets 7.00% 7.75% 7.75% N/A N/A N/A N/A
Schedule of Allocation of Plan Assets	The Company's pension plan assets at December 31, 2015 and 2014 , respectively, are categorized below according to the fair value hierarchy as defined in Note 17 , " Fair Value Measurements ": Total Level 1 Level 2 Level 3 2015 2014 2015 2014 2015 2014 2015 2014 (In thousands) Equity Securities: (A) U.S. small-cap $ 11,640 $ 16,512 $ 11,640 $ 16,512 $ — $ — $ — $ — U.S. mid-cap 28,524 46,481 10,979 17,301 17,545 29,180 — — U.S. large-cap 67,244 89,008 33,249 43,181 33,995 45,827 — — Non-U.S. 18,785 25,905 — — 18,785 25,905 — — Fixed income securities: — — — — — — — — U.S. government securities (B) 18,844 13,708 18,183 12,988 661 720 — — Non-U.S. government securities (C) 766 1,599 — — 766 1,599 — — U.S. government asset and mortgage backed securities (D) 1,056 830 — — 1,056 830 — — Corporate fixed income (E) 39,939 22,702 — — 39,939 22,702 — — State and local government securities (F) 5,725 8,005 — — 5,725 8,005 — — Other fixed income (G) 57,209 83,735 — — 57,209 83,735 — — Short-term investments (H) 3,898 6,818 — — 3,898 6,818 — — Other investments (I) 19,869 21,406 — — 1,234 3,336 18,635 18,070 Total $ 273,499 $ 336,709 $ 74,051 $ 89,982 $ 180,813 $ 228,657 $ 18,635 $ 18,070 (A) Equity securities includes investments in 1) common stock, 2) preferred stock and 3) mutual funds. Investments in common and preferred stocks are valued using quoted market prices multiplied by the number of shares owned. Investments in mutual funds are valued at the net asset value per share multiplied by the number of shares held as of the measurement date and are traded on listed exchanges. (B) U.S. government securities includes agency and treasury debt. These investments are valued using dealer quotes in an active market. (C) Non-U.S. government securities includes debt securities issued by foreign governments and are valued utilizing a price spread basis valuation technique with observable sources from investment dealers and research vendors. (D) U.S. government asset and mortgage backed securities includes government-backed mortgage funds which are valued utilizing an income approach that includes various valuation techniques and sources such as discounted cash flows models, benchmark yields and securities, reported trades, issuer trades and/or other applicable data. (E) Corporate fixed income is primarily comprised of corporate bonds and certain corporate asset-backed securities that are denominated in the U.S. dollar and are investment-grade securities. These investments are valued using dealer quotes. (F) State and local government securities include different U.S. state and local municipal bonds and asset backed securities, these investments are valued utilizing a market approach that includes various valuation techniques and sources such as value generation models, broker quotes, benchmark yields and securities, reported trades, issuer trades and/or other applicable data. (G) Other fixed income investments are actively managed fixed income vehicles that are valued at the net asset value per share multiplied by the number of shares held as of the measurement date. (H) Short-term investments include governmental agency funds, government repurchase agreements, commingled funds, and pooled funds and mutual funds. Governmental agency funds are valued utilizing an option adjusted spread valuation technique and sources such as interest rate generation processes, benchmark yields and broker quotes. Investments in governmental repurchase agreements, commingled funds and pooled funds and mutual funds are valued at the net asset value per share multiplied by the number of shares held as of the measurement date. (I) Other investments includes cash, forward contracts, derivative instruments, credit default swaps, interest rate swaps and mutual funds. Investments in interest rate swaps are valued utilizing a market approach that includes various valuation techniques and sources such as value generation models, broker quotes in active and non-active markets, benchmark yields and securities, reported trades, issuer trades and/or other applicable data. Forward contracts and derivative instruments are valued at their exchange listed price or broker quote in an active market. The mutual funds are valued at the net asset value per share multiplied by the number of shares held as of the measurement date and are traded on listed exchanges.
Schedule of Expected Benefit Payments	The following represents expected future benefit payments from the plan, which reflect expected future service, as appropriate: Other Pension Postretirement Benefits Benefits (In thousands) 2016 $ 19,164 $ 8,356 2017 20,320 8,341 2018 21,833 8,344 2019 21,341 8,281 2020 21,461 8,245 Next 5 years 106,953 38,178 $ 211,072 $ 79,745

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2015
Leases [Abstract]
Operating Leases of Lessee Disclosure	Minimum payments due in future years under these agreements in effect at December 31, 2015 are as follows: Operating Leases Royalties (In thousands) 2016 $ 20,857 $ 8,947 2017 17,277 13,991 2018 6,412 13,097 2019 3,448 12,295 2020 2,151 11,996 Thereafter 9,807 103,771 $ 59,952 $ 164,097

Risk Concentrations (Tables)

Risk Concentrations (Tables)	12 Months Ended
	Dec. 31, 2015
Risks Concentrations [Abstract]
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	The Company's foreign revenues by geographical location are as follows: Year Ended December 31, 2015 2014 2013 (In thousands) Europe $ 170,314 $ 277,565 $ 371,363 Asia 96,523 156,057 160,404 North America 40,315 78,445 80,322 Central and South America 55,323 20,496 55,493 Brokered Sales 32,848 79,354 154,442 Total $ 395,323 $ 611,917 $ 822,024

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Schedule Of Operating Segment Results	The asset amounts below represent an allocation of assets consistent with the basis used for the Company’s incentive compensation plans. The amounts in Corporate, Other and Eliminations represent primarily corporate assets (cash, receivables, investments, plant, property and equipment) as well as unassigned coal reserves, above-market acquired sales contracts and other unassigned assets. PRB APP All Other Corporate, Other and Eliminations Consolidated Year Ended December 31, 2015 Revenues $ 1,448,440 $ 834,606 $ 290,214 $ — $2,573,260 Adjusted EBITDA 258,300 82,837 17,044 (108,064 ) 250,117 Depreciation, depletion and amortization 176,257 156,273 40,768 6,047 379,345 Amortization of acquired sales contracts, net (4,158 ) (4,653 ) — — (8,811 ) Total assets 1,648,916 843,583 310,949 2,303,290 5,106,738 Capital expenditures 22,535 20,599 11,135 64,755 119,024 Year Ended December 31, 2014 Revenues $ 1,490,377 $ 1,108,358 $ 338,384 $ — $ 2,937,119 Adjusted EBITDA 198,074 110,693 56,612 (85,236 ) 280,143 Depreciation, depletion and amortization 168,522 205,732 40,125 4,369 418,748 Amortization of acquired sales contracts, net (3,961 ) (9,433 ) 207 — (13,187 ) Total assets 1,772,230 3,379,834 339,809 2,937,850 8,429,723 Capital expenditures 44,305 23,638 12,993 66,350 147,286 Year Ended December 31, 2013 Revenues $ 1,482,812 $ 1,145,801 $ 385,744 $ — $ 3,014,357 Adjusted EBITDA 206,910 88,883 94,948 (138,595 ) 252,146 Depreciation, depletion and amortization 171,324 202,952 45,741 6,425 426,442 Amortization of acquired sales contracts, net (3,656 ) (10,364 ) 4,563 — (9,457 ) Total assets 1,841,835 3,971,764 402,922 2,773,672 8,990,193 Capital expenditures 9,784 167,759 23,122 96,319 296,984
Reconciliation Statement Of Segment Income From Operations To Consolidated Income Before Income Taxes	A reconciliation of segment losses to consolidated loss from continuing operations before income taxes follows: Year Ended December 31, 2015 2014 2013 Adjusted EBITDA $ 250,117 $ 280,143 $ 252,146 Depreciation, depletion and amortization (379,345 ) (418,748 ) (426,442 ) Amortization of acquired sales contracts, net 8,811 13,187 9,457 Asset impairment costs (2,628,303 ) (24,113 ) (220,879 ) Goodwill impairment — — (265,423 ) Losses from disposed operations resulting from Patriot Coal bankruptcy (116,343 ) — — Settlement of UMWA legal claims — — (12,000 ) Interest expense, net (393,549 ) (383,188 ) (374,664 ) Nonoperating expense (27,910 ) — (42,921 ) Loss from continuing operations before income taxes $ (3,286,522 ) $ (532,719 ) $ (1,080,726 )

Quarterly Selected Financial 60

Quarterly Selected Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	Year Ended December 31, 2015 March 31 June 30 September 30 December 31 (a) (a) (a) (a) (In thousands, except per share data) Revenues $ 677,005 $ 644,462 $ 688,544 563,249 Gross profit (loss) $ 14,256 $ (16,507 ) $ 47,275 (44,964 ) Asset impairment and mine closure costs $ — $ 19,146 $ 2,120,292 488,865 Loss from operations $ (19,712 ) $ (69,546 ) $ (2,236,772 ) $ (539,033 ) Net loss $ (113,195 ) $ (168,103 ) $ (1,999,476 ) $ (632,368 ) Diluted loss per common share $ (5.32 ) $ (7.93 ) $ (93.91 ) $ (29.70 ) Year Ended December 31, 2014 March 31 June 30 September 30 December 31 (a) (a) (b) (a) (b) (a) (b) (In thousands, except per share data) Revenues $ 735,971 $ 713,776 $ 742,180 $ 745,192 Gross profit (loss) $ (49,842 ) $ (6,350 ) $ (5,851 ) $ 32,264 Asset impairment and mine closure costs $ — $ 1,512 $ 5,060 $ 17,541 Loss from operations $ (73,123 ) $ (35,805 ) $ (35,300 ) $ (5,303 ) Net loss $ (124,140 ) $ (96,860 ) $ (97,218 ) $ (240,135 ) Diluted loss per common share $ (5.85 ) $ (4.57 ) $ (4.58 ) $ (11.31 ) (a) Challenging coal markets resulted in impairment charges relating to mining and other operations, investments in equity method subsidiaries and prepaid mining royalties in 2015 and 2014. See further discussion in Note 5 , " Impairment Charges and Mine Closure Costs " and Note 10 , " Equity Method Investments and Membership Interests in Joint Ventures ." (b) The Company determined that it would not realize the benefit from federal and state net operating losses it generated in 2014, based on projections of future taxable income, and as a result, recorded a valuation allowance against net operating losses of $23.8. million , $18.3 million , $15.8 million and $807.2 million in the second, third and fourth quarters of 2014, respectively.

Supplemental Consolidating Fi61

Supplemental Consolidating Financial Information (Tables)	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of Condensed Consolidating Statements of Income	Condensed Consolidating Statements of Operations and Comprehensive Income Year Ended December 31, 2015 Parent/Issuer Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated (In thousands) Revenues $ — $ 2,573,260 $ — $ — $ 2,573,260 Costs, expenses and other Cost of sales (exclusive of items shown separately below) 22,378 2,186,804 — (2,749 ) 2,206,433 Depreciation, depletion and amortization 3,775 375,568 2 — 379,345 Amortization of acquired sales contracts, net — (8,811 ) — — (8,811 ) Change in fair value of coal derivatives and coal trading activities, net — (1,583 ) — — (1,583 ) Asset impairment and mine closure costs 15,437 2,612,866 — — 2,628,303 Losses from disposed operations resulting from Patriot Coal bankruptcy 116,343 — — — 116,343 Selling, general and administrative expenses 69,384 25,737 5,725 (2,063 ) 98,783 Other operating expense (income), net 5,869 13,021 (4,192 ) 4,812 19,510 233,186 5,203,602 1,535 — 5,438,323 Loss from investment in subsidiaries (2,574,565 ) — — 2,574,565 — Loss from operations (2,807,751 ) (2,630,342 ) (1,535 ) 2,574,565 (2,865,063 ) Interest expense, net Interest expense (478,432 ) (26,284 ) (4,916 ) 111,653 (397,979 ) Interest and investment income 27,510 82,881 5,692 (111,653 ) 4,430 (450,922 ) 56,597 776 — (393,549 ) Net loss resulting from early retirement of debt and debt restructuring (27,910 ) — — — (27,910 ) Loss from continuing operations before income taxes (3,286,583 ) (2,573,745 ) (759 ) 2,574,565 (3,286,522 ) Provision for (benefit from) income taxes (373,441 ) — 61 — (373,380 ) Net loss (2,913,142 ) (2,573,745 ) (820 ) 2,574,565 (2,913,142 ) Total comprehensive loss $ (2,918,198 ) $ (2,579,601 ) $ (820 ) $ 2,580,421 $ (2,918,198 ) Condensed Consolidating Statements of Operations and Comprehensive Income Year Ended December 31, 2014 Parent/Issuer Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated (In thousands) Revenues $ — $ 2,937,119 $ — $ — $ 2,937,119 Costs, expenses and other Cost of sales (exclusive of items shown separately below) 3,016 2,566,572 — (3,395 ) 2,566,193 Depreciation, depletion and amortization 5,154 413,559 35 — 418,748 Amortization of acquired sales contracts, net — (13,187 ) — — (13,187 ) Change in fair value of coal derivatives and coal trading activities, net — (3,686 ) — — (3,686 ) Asset impairment and mine closure costs 3,642 20,471 — — 24,113 Selling, general and administrative expenses 79,902 29,739 6,626 (2,044 ) 114,223 Other operating income, net (4,480 ) (15,726 ) (4,987 ) 5,439 (19,754 ) 87,234 2,997,742 1,674 — 3,086,650 Loss from investment in subsidiaries (13,085 ) — — 13,085 — Loss from operations (100,319 ) (60,623 ) (1,674 ) 13,085 (149,531 ) Interest expense, net Interest expense (463,823 ) (26,137 ) (4,259 ) 103,273 (390,946 ) Interest and investment income 31,389 74,511 5,131 (103,273 ) 7,758 (432,434 ) 48,374 872 — (383,188 ) Loss from continuing operations before income taxes (532,753 ) (12,249 ) (802 ) 13,085 (532,719 ) Provision for (benefit from) income taxes 25,600 — 34 — 25,634 Net loss (558,353 ) (12,249 ) (836 ) 13,085 (558,353 ) Total comprehensive loss $ (592,804 ) $ (34,439 ) $ (836 ) $ 35,275 $ (592,804 ) Condensed Consolidating Statements of Operations and Comprehensive Income Year Ended December 31, 2013 Parent/Issuer Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations Consolidated (In thousands) Revenues $ — $ 3,014,357 $ — $ — $ 3,014,357 Costs, expenses and other — Cost of sales (exclusive of items shown separately below) 9,117 2,657,583 — (3,564 ) 2,663,136 Depreciation, depletion and amortization 5,949 420,458 35 — 426,442 Amortization of acquired sales contracts, net — (9,457 ) — — (9,457 ) Change in fair value of coal derivatives and coal trading activities, net — 7,845 — — 7,845 Asset impairment and mine closure costs 78,150 142,729 — — 220,879 Goodwill impairment — 265,423 — — 265,423 Selling, general and administrative expenses 88,820 39,825 7,038 (2,235 ) 133,448 Other operating income, net 4,209 (34,856 ) (5,370 ) 5,799 (30,218 ) 186,245 3,489,550 1,703 — 3,677,498 Loss from investment in subsidiaries (328,889 ) — — 328,889 — Income (loss) from operations (515,134 ) (475,193 ) (1,703 ) 328,889 (663,141 ) Interest expense, net Interest expense (449,614 ) (24,747 ) (4,214 ) 97,308 (381,267 ) Interest and investment income 30,285 68,248 5,378 (97,308 ) 6,603 (419,329 ) 43,501 1,164 — (374,664 ) Other non-operating expense Net loss resulting from early retirement of debt (42,921 ) — — — (42,921 ) Loss from continuing operations before income taxes (977,384 ) (431,692 ) (539 ) 328,889 (1,080,726 ) Provision for (benefit from) income taxes (335,552 ) — 54 — (335,498 ) Loss from continuing operations (641,832 ) (431,692 ) (593 ) 328,889 (745,228 ) Income from discontinued operations, net of tax — 103,396 — — 103,396 Net Loss (641,832 ) (328,296 ) (593 ) 328,889 (641,832 ) Total comprehensive income (loss) $ (587,633 ) $ (304,278 ) $ (593 ) $ 304,871 $ (587,633 )
Schedule of Condensed Consolidating Balance Sheets	Condensed Consolidating Balance Sheets December 31, 2015 Parent/Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated (In thousands) Assets Cash and cash equivalents $ 337,646 $ 100,428 $ 12,707 $ — $ 450,781 Short term investments 200,192 — — — 200,192 Restricted cash — — 97,542 — 97,542 Receivables 12,463 3,153 124,581 (4,430 ) 135,767 Inventories — 196,720 — — 196,720 Other 83,017 38,794 969 — 122,780 Total current assets 633,318 339,095 235,799 (4,430 ) 1,203,782 Property, plant and equipment, net 7,747 3,610,869 — 413 3,619,029 Investment in subsidiaries 4,887,905 — — (4,887,905 ) — Intercompany receivables — 2,253,312 — (2,253,312 ) — Note receivable from Arch Western 675,000 — — (675,000 ) — Other 39,302 243,806 819 — 283,927 Total assets $ 6,243,272 $ 6,447,082 $ 236,618 $ (7,820,234 ) $ 5,106,738 Liabilities and Stockholders’ Equity (Deficit) Accounts payable $ 8,495 $ 119,633 $ 3 $ — $ 128,131 Accrued expenses and other current liabilities 162,268 170,575 1,037 (4,430 ) 329,450 Current maturities of debt 5,096,460 10,750 — — 5,107,210 Total current liabilities 5,267,223 300,958 1,040 (4,430 ) 5,564,791 Long-term debt — 30,953 — — 30,953 Intercompany payables 2,043,308 — 210,005 (2,253,313 ) — Note payable to Arch Coal — 675,000 — (675,000 ) — Asset retirement obligations 1,005 395,654 — — 396,659 Accrued pension benefits 12,390 14,983 — — 27,373 Accrued postretirement benefits other than pension 79,826 19,984 — — 99,810 Accrued workers’ compensation 24,247 88,023 — — 112,270 Deferred income taxes — — — — — Other noncurrent liabilities 59,976 58,847 348 — 119,171 Total liabilities 7,487,975 1,584,402 211,393 (2,932,743 ) 6,351,027 Stockholders’ equity (deficit) (1,244,703 ) 4,862,680 25,225 (4,887,491 ) (1,244,289 ) Total liabilities and stockholders’ equity (deficit) $ 6,243,272 $ 6,447,082 $ 236,618 $ (7,820,234 ) $ 5,106,738 Condensed Consolidating Balance Sheets December 31, 2014 Parent/Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated (In thousands) Assets Cash and cash equivalents $ 572,185 $ 150,358 $ 11,688 $ — $ 734,231 Short term investments 248,954 — — — 248,954 Restricted cash — — 5,678 — 5,678 Receivables 9,656 15,933 211,043 (4,615 ) 232,017 Inventories — 190,253 — — 190,253 Other 89,211 41,455 952 — 131,618 Total current assets 920,006 397,999 229,361 (4,615 ) 1,542,751 Property, plant and equipment, net 10,470 6,442,623 2 363 6,453,458 Investment in subsidiaries 7,464,221 — — (7,464,221 ) — Intercompany receivables 2,021,110 — (2,021,110 ) — Note receivable from Arch Western 675,000 — — (675,000 ) — Other 131,884 300,058 1,572 — 433,514 Total assets $ 9,201,581 $ 9,161,790 $ 230,935 $ (10,164,583 ) $ 8,429,723 Liabilities and Stockholders’ Equity Accounts payable $ 23,394 $ 156,664 $ 55 $ — $ 180,113 Accrued expenses and other current liabilities 85,899 220,017 1,095 (4,615 ) 302,396 Current maturities of debt 27,625 9,260 — — 36,885 Total current liabilities 136,918 385,941 1,150 (4,615 ) 519,394 Long-term debt 5,084,839 38,646 — 5,123,485 Intercompany payables 1,817,755 — 203,355 (2,021,110 ) — Note payable to Arch Coal — 675,000 — (675,000 ) — Asset retirement obligations 981 397,915 — — 398,896 Accrued pension benefits 5,967 10,293 — — 16,260 Accrued postretirement benefits other than pension 4,430 28,238 — — 32,668 Accrued workers’ compensation 9,172 85,119 — — 94,291 Deferred income taxes 422,809 — — — 422,809 Other noncurrent liabilities 50,919 102,461 386 — 153,766 Total liabilities 7,533,790 1,723,613 204,891 (2,700,725 ) 6,761,569 Stockholders’ equity 1,667,791 7,438,177 26,044 (7,463,858 ) 1,668,154 Total liabilities and stockholders’ equity $ 9,201,581 $ 9,161,790 $ 230,935 $ (10,164,583 ) $ 8,429,723
Schedule of Condensed Consolidating Statements of Cash Flows	Condensed Consolidating Statements of Cash Flows Year Ended December 31, 2015 Parent/Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated (In thousands) Cash provided by (used in) operating activities $ (445,136 ) $ 314,535 $ 86,234 $ — $ (44,367 ) Investing Activities Capital expenditures (1,108 ) (117,916 ) — — (119,024 ) Additions to prepaid royalties — (5,871 ) — — (5,871 ) Proceeds from disposals and divestitures — 2,191 — — 2,191 Purchases of short term investments (246,735 ) — — — (246,735 ) Proceeds from sales of short term investments 290,205 — — — 290,205 Proceeds from sales of equity investments and securities — 2,259 — — 2,259 Withdrawals (deposits) of restricted cash — — (91,864 ) — (91,864 ) Investments in and advances to affiliates (913 ) (10,589 ) — — (11,502 ) Cash provided by (used in) investing activities 41,449 (129,926 ) (91,864 ) — (180,341 ) Financing Activities Payments on term loan (19,500 ) — — — (19,500 ) Net payments on other debt (2,692 ) (8,640 ) — — (11,332 ) Expenses related to debt restructuring (27,910 ) — — — (27,910 ) Transactions with affiliates, net 219,250 (225,899 ) 6,649 — — Cash provided by (used in) financing activities 169,148 (234,539 ) 6,649 — (58,742 ) Increase (decrease) in cash and cash equivalents (234,539 ) (49,930 ) 1,019 — (283,450 ) Cash and cash equivalents, beginning of period 572,185 150,358 11,688 — 734,231 Cash and cash equivalents, end of period $ 337,646 $ 100,428 $ 12,707 $ — $ 450,781 Condensed Consolidating Statements of Cash Flows Year Ended December 31, 2014 Parent/Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated (In thousands) Cash provided by (used in) operating activities $ (324,688 ) $ 305,048 $ (13,942 ) $ — $ (33,582 ) Investing Activities Capital expenditures (2,700 ) (144,586 ) — — (147,286 ) Additions to prepaid royalties — (7,317 ) — — (7,317 ) Proceeds from disposals and divestitures 57,625 4,733 — — 62,358 Purchases of short term investments (211,929 ) — — — (211,929 ) Proceeds from sales of short term investments 205,611 — — — 205,611 Proceeds from sales of investments in equity securities 9,464 — — — 9,464 Withdrawals (deposits) of restricted cash — — (5,678 ) — (5,678 ) Investments in and advances to affiliates (2,541 ) (14,116 ) — — (16,657 ) Cash provided by (used in) investing activities 55,530 (161,286 ) (5,678 ) — (111,434 ) Financing Activities Payments on term loan (19,500 ) — — — (19,500 ) Net payments on other debt (1,258 ) (4,437 ) — — (5,695 ) Debt financing costs (2,219 ) — (2,300 ) — (4,519 ) Dividends paid (2,123 ) — — — (2,123 ) Other (15 ) — — — (15 ) Transactions with affiliates, net 67,125 (89,385 ) 22,260 — — Cash provided by (used in) financing activities 42,010 (93,822 ) 19,960 — (31,852 ) Increase (decrease) in cash and cash equivalents (227,148 ) 49,940 340 — (176,868 ) Cash and cash equivalents, beginning of period 799,333 100,418 11,348 — 911,099 Cash and cash equivalents, end of period $ 572,185 $ 150,358 $ 11,688 $ — $ 734,231 Condensed Consolidating Statements of Cash Flows Year Ended December 31, 2013 Parent/Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated (In thousands) Cash provided by (used in) operating activities $ (632,060 ) $ 637,193 $ 50,609 $ — $ 55,742 Investing Activities Capital expenditures (3,320 ) (293,664 ) — — (296,984 ) Proceeds from disposals and divestitures — 433,453 — — 433,453 Proceeds from sales-leaseback transaction — 34,919 — — 34,919 Investments in and advances to affiliates (5,451 ) (10,321 ) — 512 (15,260 ) Purchases of short term investments (213,726 ) — — — (213,726 ) Proceeds from sales of short term investments 194,537 — — — 194,537 Additions to prepaid royalties — (14,947 ) — — (14,947 ) Change in restricted cash 3,453 — — — 3,453 Cash provided by (used in) investing activities (24,507 ) 149,440 — 512 125,445 Financing Activities Contributions from parent — 512 — (512 ) — Proceeds from term loan and senior notes 644,000 — — — 644,000 Payments to retire debt (628,660 ) — — — (628,660 ) Payments on term loan (17,250 ) — — — (17,250 ) Net payments on other debt (6,324 ) (512 ) — — (6,836 ) Debt financing costs (19,864 ) — (625 ) — (20,489 ) Dividends paid (25,475 ) — — — (25,475 ) Transactions with affiliates, net 838,160 (786,683 ) (51,477 ) — — Cash provided by (used in) financing activities 784,587 (786,683 ) (52,102 ) (512 ) (54,710 ) Increase in cash and cash equivalents 128,020 (50 ) (1,493 ) — 126,477 Cash and cash equivalents, beginning of period 671,313 100,468 12,841 — 784,622 Cash and cash equivalents, end of period $ 799,333 $ 100,418 $ 11,348 $ — $ 911,099

Basis of Presentation (Narrativ

Basis of Presentation (Narrative) (Details)	Aug. 04, 2015	Dec. 31, 2015
Debt Instrument [Line Items]
Reverse stock split conversion ratio	0.1
7.00% Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Senior notes interest rate		7.00%
9.875% Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Senior notes interest rate		9.875%
8.00% Senior Secured Notes due 2019 [Member]
Debt Instrument [Line Items]
Senior notes interest rate		8.00%
7.25% Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Senior notes interest rate		7.25%
7.25% Senior Notes Due 2021 [Member]
Debt Instrument [Line Items]
Senior notes interest rate		7.25%

Accounting Policies (Narrative)

Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Statutory Accounting Practices
Mineral rights	$ 2,400,000	$ 4,700,000
Future lease bonus payments	94,600
Deferred finance costs, net	112,918	89,100
Deferred finance costs, current	$ 65,600	$ 25,500
Exploration and Production Equipment [Member] | Minimum [Member]
Statutory Accounting Practices
Estimated useful life	5 years
Exploration and Production Equipment [Member] | Maximum [Member]
Statutory Accounting Practices
Estimated useful life	32 years
Building and Building Improvements [Member] | Minimum [Member]
Statutory Accounting Practices
Estimated useful life	10 years
Building and Building Improvements [Member] | Maximum [Member]
Statutory Accounting Practices
Estimated useful life	30 years
Mining Properties and Mineral Rights [Member] | Minimum [Member]
Statutory Accounting Practices
Term of contract	10 years
Mining Properties and Mineral Rights [Member] | Maximum [Member]
Statutory Accounting Practices
Term of contract	50 years
Capital Addition Purchase Commitments [Member]
Statutory Accounting Practices
Future lease bonus payments	$ 60,000

Divestitures (Schedule of Resul

Divestitures (Schedule of Results of Discontinued Operations) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Discontinued Operations and Disposal Groups [Abstract]
Total Revenues			$ 219,002
Income from discontinued operations before income taxes			32,167
Gain on sale	$ 2,270	$ 27,512	120,321
Less: income tax expense			49,092
Income from discontinued operations, including gain on sale - net of tax	$ 0	$ 0	$ 103,396
Basic earnings per common share from discontinued operations (in dollars per share)			$ 4.87
Diluted earnings per common share from discontinued operations (in dollars per share)			$ 4.87

Divestitures (Narrative) (Detai

Divestitures (Narrative) (Details) $ in Millions	Jun. 27, 2013mining_complex	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Discontinued Operations and Disposal Groups [Abstract]
Number of longwall mining complexes | mining_complex	2
Proceeds from disposals and divestitures		$ 46.7	$ 422.7
Pre-tax gain on divestiture		$ 17.8

Accumulated Other Comprehensi66

Accumulated Other Comprehensive Income (Loss) (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprenhensive Income (Loss) [Roll Forward]
Balance at	$ 3,241	$ 37,692
Unrealized gains (losses)	(8,153)	(24,566)
Amounts reclassified from accumulated other comprehensive income (loss)	3,097	(9,885)
Balance at	(1,815)	3,241
Derivative Instruments [Member]
Accumulated Other Comprenhensive Income (Loss) [Roll Forward]
Balance at	2,550	565
Unrealized gains (losses)	3,903	3,677
Amounts reclassified from accumulated other comprehensive income (loss)	(6,128)	(1,692)
Balance at	325	2,550
Pension, Postretirement and Other Post-Employment Benefits [Member]
Accumulated Other Comprenhensive Income (Loss) [Roll Forward]
Balance at	2,860	31,112
Unrealized gains (losses)	(8,723)	(22,516)
Amounts reclassified from accumulated other comprehensive income (loss)	5,142	(5,736)
Balance at	(721)	2,860
Available-for-Sale Securities [Member]
Accumulated Other Comprenhensive Income (Loss) [Roll Forward]
Balance at	(2,169)	6,015
Unrealized gains (losses)	(3,333)	(5,727)
Amounts reclassified from accumulated other comprehensive income (loss)	4,083	(2,457)
Balance at	$ (1,419)	$ (2,169)

Accumulated Other Comprehensi67

Accumulated Other Comprehensive Income (Loss) (Schedule of Reclassifications) (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
Accumulated Other Comprehensive Income (Loss) [Line Items]
Revenues	$ 563,249	$ 688,544	$ 644,462	$ 677,005	$ 745,192	$ 742,180	$ 713,776	$ 735,971	$ 2,573,260	$ 2,937,119	$ 3,014,357
Loss from continuing operations before income taxes									(3,286,522)	(532,719)	(1,080,726)
Provision for (benefit from) income taxes									373,380	(25,634)	335,498
Net loss	$ (632,368)	$ (1,999,476)	$ (168,103)	$ (113,195)	$ (240,135)	$ (97,218)	$ (96,860)	$ (124,140)	(2,913,142)	(558,353)	$ (641,832)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax									(3,097)	9,885
Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax									6,128	1,692
Pension, Postretirement and Other Post-Employment Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax									(5,142)	5,736
Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax									(4,083)	2,457
Reclassification out of accumulated other comprehensive income [Member] | Derivative Instruments [Member] | Commodity Contract [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Revenues									9,575	2,643
Provision for (benefit from) income taxes									(3,447)	(951)
Net loss									6,128	1,692
Reclassification out of accumulated other comprehensive income [Member] | Pension, Postretirement and Other Post-Employment Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of prior service credits									8,335	11,760
Amortization of net actuarial gains (losses)									(16,369)	(2,797)
Loss from continuing operations before income taxes									(8,034)	8,963
Provision for (benefit from) income taxes									2,892	(3,227)
Net loss									(5,142)	5,736
Reclassification out of accumulated other comprehensive income [Member] | Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and investment income									(6,391)	3,838
Provision for (benefit from) income taxes									2,308	(1,381)
Net loss									$ (4,083)	$ 2,457

Impairment Charges and Mine C68

Impairment Charges and Mine Closure Costs (Details) - USD ($) $ in Thousands	3 Months Ended									6 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	Sep. 30, 2013	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Impaired Long-Lived Assets Held and Used [Line Items]
Asset impairment and mine closure costs	$ 488,865	$ 2,120,292	$ 19,146	$ 0	$ 17,541	$ 5,060	$ 1,512	$ 0		$ 2,600,000	$ 2,628,303	$ 24,113	$ 220,879
Prepaid royalties											41,990	15,356	1,104
Impairment charge of higher-cost mining complex			5,600
Restructuring charges											5,100
Plant and equipment									$ 142,800		199,107	1,512	$ 36,296
Fair value of assets									$ 71,300
Royalty Agreements [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Prepaid royalties			$ 12,200
Impairment charge					$ 15,400							$ 48,000
APP [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Asset impairment and mine closure costs											2,200,000
Other Segments [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Asset impairment and mine closure costs											$ 400,000

Impairment Charges and Mine C69

Impairment Charges and Mine Closure Costs (Summary Asset Impairments and Mine Closure Costs) (Details) - USD ($) $ in Thousands	3 Months Ended									6 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	Sep. 30, 2013	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Impairment Charges and Mine Closure Costs [Abstract]
Coal lands and mineral rights											$ 2,210,488	$ 0	$ 79,094
Plant and equipment									$ 142,800		199,107	1,512	36,296
Deferred development											159,474	0	13,451
Prepaid royalties											41,990	15,356	1,104
Equity investments											21,325	0	28,947
Notes receivable											0	0	49,203
Inventories											66	0	12,765
Other											(4,147)	7,245	19
Asset impairment and mine closure costs	$ 488,865	$ 2,120,292	$ 19,146	$ 0	$ 17,541	$ 5,060	$ 1,512	$ 0		$ 2,600,000	$ 2,628,303	$ 24,113	$ 220,879

Goodwill (Narrative) (Details)

Goodwill (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Line Items]
Goodwill impairment	$ 0	$ 0	$ 265,423
APP [Member]
Goodwill [Line Items]
Goodwill impairment		$ 265,400

Goodwill (Schedule of Goodwill)

Goodwill (Schedule of Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Roll Forward]
Balance		$ 0	$ 265,423
Goodwill impairment	$ 0	$ 0	(265,423)
Balance			$ 0

Losses from disposed operatio72

Losses from disposed operations resulting from Patriot Coal Bankruptcy (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Losses related to previously disposed off operations			$ (17.8)
Discontinued Operations, Held-for-sale or Disposed of by Sale [Member] | Magnum [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Losses related to previously disposed off operations		$ 149.3	$ 116.3
Adjustment to prior period gain (loss) on disposal	$ 33

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Coal	$ 85,043	$ 71,901
Repair parts and supplies	111,677	118,352
Inventories	196,720	190,253
Inventories
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for slow-moving and obsolete inventories	$ 6,000	$ 6,600

Investments in Available-for-74

Investments in Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	$ 204,441	$ 257,500
Gross Unrealized Gains	668	4,125
Gross Unrealized Losses	(3,199)	(7,526)
Fair Value	201,910	254,099
Total Investments	200,192	248,954
Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Corporate notes and bonds	190,197	248,954
Total Investments	200,192	248,954
Other Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Equity Securities, Fair Value	1,718	5,145
US Government and Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	10,007
Gross Unrealized Gains	0
Gross Unrealized Losses	(12)
Fair Value	9,995
US Government and Agency Securities [Member] | Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Corporate notes and bonds	9,995
Corporate Notes and Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt Securities, Amortized Cost Basis	190,496	253,590
Debt Securities, Gross Unrealized Gains	0	0
Debt Securities, Gross Unrealized Losses	(299)	(4,636)
Debt Securities, Fair Value	190,197	248,954
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Equity Securities, Amortized Cost Basis	3,938	3,910
Equity Securities, Gross Unrealized Gains	668	4,125
Equity Securities, Gross Unrealized Losses	(2,888)	(2,890)
Equity Securities, Fair Value	$ 1,718	$ 5,145

Investments in Available-for-75

Investments in Available-for-Sale Securities (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Available-for-sale Securities [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 184.6	$ 163
Available-for-sale Securities, Continuous Unrealized Loss Position, Greater than Twelve Months, Fair Value	$ 15.8	$ 86.1

Equity Method Investments and76

Equity Method Investments and Membership Interests in Joint Ventures (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Sep. 30, 2015	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Investments in and Advances to Affiliates, at Fair Value, Period Increase (Decrease)				$ (18,360)	$ 4,054	$ 788
Impairment of equity investment				$ (21,325)	0	(28,947)
Provision for Loan, Lease, and Other Losses			$ (5,200)
Knight Hawk [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage				49.00%
Investments in and Advances to Affiliates, at Fair Value, Period Increase (Decrease)				$ (29,862)	(12,603)	(13,536)
Impairment of equity investment				$ 0		0
DTA [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage				21.875%
Investments in and Advances to Affiliates, at Fair Value, Period Increase (Decrease)				$ 3,207	3,774	3,644
Impairment of equity investment						0
Millennium [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage				38.00%
Investments in and Advances to Affiliates, at Fair Value, Period Increase (Decrease)				$ 7,052	6,742	6,476
Impairment of equity investment				$ 0
Tongue River [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage				35.00%
Investments in and Advances to Affiliates, at Fair Value, Period Increase (Decrease)				$ 913	$ 2,541	4,004
Impairment of equity investment	$ (21,300)			$ (21,325)		0
DKRW [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage				24.00%
Other than Temporary Impairment Losses, Investments		$ 57,700
Investments in and Advances to Affiliates, at Fair Value, Period Increase (Decrease)				$ 0
Impairment of equity investment		13,700				(13,683)
Provision for Loan, Lease, and Other Losses		$ (44,000)
Tenaska [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage			35.00%
Other than Temporary Impairment Losses, Investments			$ 20,500
Impairment of equity investment			$ 15,300	0		$ (15,264)
Equity Method Investee [Member]
Schedule of Equity Method Investments [Line Items]
Future development costs, maximum limit				$ 58,500

Equity Method Investments and77

Equity Method Investments and Membership Interests in Joint Ventures (Schedule of Equity Method Investments) (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Sep. 30, 2015	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]
Beginning Balance				$ 235,842	$ 221,456	$ 242,215
Advances to (distributions from) affiliates, net				(18,360)	4,054	788
Equity in comprehensive income (loss)				7,979	10,332	7,400
Impairment of equity investment				(21,325)	0	(28,947)
Sale of equity investment				(2,259)
Ending Balance				201,877	235,842	221,456
Knight Hawk [Member]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]
Beginning Balance				158,477	152,806	149,063
Advances to (distributions from) affiliates, net				(29,862)	(12,603)	(13,536)
Equity in comprehensive income (loss)				22,977	18,274	17,279
Impairment of equity investment				0		0
Ending Balance				151,592	158,477	152,806
DTA [Member]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]
Beginning Balance				13,738	14,137	15,462
Advances to (distributions from) affiliates, net				3,207	3,774	3,644
Equity in comprehensive income (loss)				(3,706)	(4,173)	(4,969)
Impairment of equity investment						0
Ending Balance				13,239	13,738	14,137
Millennium [Member]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]
Beginning Balance				40,223	35,894	32,214
Advances to (distributions from) affiliates, net				7,052	6,742	6,476
Equity in comprehensive income (loss)				(9,686)	(2,413)	(2,796)
Impairment of equity investment				0
Ending Balance				37,589	40,223	35,894
Tongue River [Member]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]
Beginning Balance				20,740	18,419	14,697
Advances to (distributions from) affiliates, net				913	2,541	4,004
Equity in comprehensive income (loss)				(328)	(220)	(282)
Impairment of equity investment	$ (21,300)			(21,325)		0
Ending Balance				0	20,740	18,419
DKRW [Member]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]
Beginning Balance						15,515
Advances to (distributions from) affiliates, net				0
Equity in comprehensive income (loss)						(1,832)
Impairment of equity investment		$ 13,700				(13,683)
Tenaska [Member]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]
Beginning Balance						15,264
Impairment of equity investment			$ 15,300	0		(15,264)
Ending Balance				0
Other Affiliates [Member]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]
Beginning Balance				2,664	200
Advances to (distributions from) affiliates, net				330	3,600	200
Equity in comprehensive income (loss)				(1,278)	(1,136)
Impairment of equity investment				0		0
Sale of equity investment				(2,259)
Ending Balance				$ (543)	$ 2,664	$ 200

Acquired Sales Contracts (Narra

Acquired Sales Contracts (Narrative) (Details) $ in Millions	Dec. 31, 2015USD ($)
Acquired Sales Contracts [Abstract]
2,016	$ 3.3
2,017	3.7
2,018	3.7
2,019	3.7
2,020	$ 0.3

Acquired Sales Contracts (Sched

Acquired Sales Contracts (Schedule of Acquired Sales Contracts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Acquired Finite-Lived Intangible Assets And Liabilities By Major Class [Line Items]
Prepaid royalties	$ 41,990	$ 15,356	$ 1,104
Acquired fair value, Assets	131,299	131,299
Acquired fair value, Liabilities	166,697	166,697
Accumulated amortization, Asset	(130,839)	(130,363)
Accumulated amortization, Liabilities	(151,354)	(134,988)
Total, Assets	460	936
Total, Liabilities	15,343	31,709
Net total, Liabilities	(14,883)	(30,773)
Coal Supply Agreement, Liabilities	3,852	12,453
Other Current Assets [Member]
Acquired Finite-Lived Intangible Assets And Liabilities By Major Class [Line Items]
Coal supply agreement, Assets	460	462
Accrued Liabilities [Member]
Acquired Finite-Lived Intangible Assets And Liabilities By Major Class [Line Items]
Coal Supply Agreement, Liabilities	3,852	12,453
Other Assets [Member]
Acquired Finite-Lived Intangible Assets And Liabilities By Major Class [Line Items]
Coal supply agreement, Assets	0	474
Other Noncurrent Liabilities [Member]
Acquired Finite-Lived Intangible Assets And Liabilities By Major Class [Line Items]
Coal Supply Agreement, Liabilities	$ 11,491	$ 19,256

Derivatives (Narrative) (Detail

Derivatives (Narrative) (Details) $ in Thousands, gal in Millions	12 Months Ended
	Dec. 31, 2015USD ($)gal$ / option	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Derivative [Line Items]
Right to reclaim cash collateral, asset	$ 107,028	$ 98,686
Right to reclaim cash collateral, liability	107,028	98,686
Net unrealized and realized gains (losses) related to trading portfolio	5,700	3,200	$ 4,900
Year One [Member]
Derivative [Line Items]
Value of trading portfolio realized	$ 5,800
Diesel Purchases [Member] | Heating Oil [Member]
Derivative [Line Items]
Quantities under derivative contracts | gal	56
Average strike price (in dollars per option) | $ / option	1.98
Diesel Purchases [Member] | Minimum [Member]
Derivative [Line Items]
Gallons of diesel fuel purchased annually | gal	50
Diesel Purchases [Member] | Maximum [Member]
Derivative [Line Items]
Gallons of diesel fuel purchased annually | gal	58
Other Current Liabilities [Member]
Derivative [Line Items]
Right to reclaim cash collateral, liability	$ 2,400	2,400
Other Current Assets [Member]
Derivative [Line Items]
Right to reclaim cash collateral, asset	$ 1,700	$ 1,700

Derivatives (Schedule of Price

Derivatives (Schedule of Price Risk Derivatives) (Details) T in Thousands	Dec. 31, 2015T
Coal Sales [Member]
Derivative [Line Items]
Derivatives Held	480
Coal Purchases [Member]
Derivative [Line Items]
Derivatives Held	255
Year One [Member] | Coal Sales [Member]
Derivative [Line Items]
Derivatives Held	480
Year One [Member] | Coal Purchases [Member]
Derivative [Line Items]
Derivatives Held	255
Year Two [Member] | Coal Sales [Member]
Derivative [Line Items]
Derivatives Held	0
Year Two [Member] | Coal Purchases [Member]
Derivative [Line Items]
Derivatives Held	0

Derivatives (Disclosure of Fair

Derivatives (Disclosure of Fair Value of Derivatives) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Derivative [Line Items]
Derivative Assets	$ 116,080	$ 112,243
Derivative Liabilities	(107,028)	(99,452)
Effect of counterparty netting in derivative assets	(107,028)	(98,686)
Effect of counterparty netting in derivative liabilities	107,028	98,686
Net derivative assets as classified in the balance sheet	9,052	13,557
Net derivative liabilities as classified in the balance sheet	0	(766)
Net derivatives as classified in the balance sheet	9,052	12,791
Designated as Hedging Instrument [Member] | Coal [Member]
Derivative [Line Items]
Derivative Assets	4	6,535
Derivative Liabilities	(20)	(2,492)
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Assets	116,076	105,708
Derivative Liabilities	(107,008)	(96,960)
Not Designated as Hedging Instrument [Member] | Heating Oil-Diesel Purchases [Member]
Derivative [Line Items]
Derivative Assets	1,017	300
Not Designated as Hedging Instrument [Member] | Coal Held for Trading Purposes [Member]
Derivative [Line Items]
Derivative Assets	110,653	96,898
Derivative Liabilities	(104,814)	(93,272)
Not Designated as Hedging Instrument [Member] | Coal [Member]
Derivative [Line Items]
Derivative Assets	3,912	8,510
Derivative Liabilities	(1,947)	(3,688)
Not Designated as Hedging Instrument [Member] | Natural Gas [Member]
Derivative [Line Items]
Derivative Assets	494	0
Derivative Liabilities	$ (247)	$ 0

Derivatives (Net Derivatives as

Derivatives (Net Derivatives as Reflected on the Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Net derivatives as classified in the balance sheet	$ 9,052	$ 12,791
Other Current Assets [Member] | Heating Oil [Member]
Derivatives, Fair Value [Line Items]
Net derivatives as classified in the balance sheet	1,017	300
Coal Derivative Assets [Member] | Coal [Member]
Derivatives, Fair Value [Line Items]
Net derivatives as classified in the balance sheet	8,035	13,257
Coal Derivative Liabilities [Member] | Coal [Member]
Derivatives, Fair Value [Line Items]
Net derivatives as classified in the balance sheet	$ 0	$ (766)

Derivatives (Effects of Derivat

Derivatives (Effects of Derivatives on Measures of Financial Performance) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI (Effective Portion)	$ 6,098	$ 5,745	$ 188
Gains (Losses) Reclassified from OCI into Income (Effective Portion)	(9,575)	(2,643)	(2,981)
Coal Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI (Effective Portion)	12,816	10,842	(338)
Gains (Losses) Reclassified from OCI into Income (Effective Portion)	(18,635)	(5,336)	(3,664)
Coal Purchases [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI (Effective Portion)	(6,718)	(5,097)	526
Gains (Losses) Reclassified from OCI into Income (Effective Portion)	(9,060)	(2,693)	(683)
Coal [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives	(3,883)	430	(12,700)
Coal derivative settlements, non-hedging	3,236	5,956	32,534
Heating Oil-Diesel Purchases [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gains (Losses)	(8,294)	(7,848)	(9,791)
Heating Oil-Fuel Surchages [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gains (Losses)	0	$ (405)	(947)
Natural Gas [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gains (Losses)	878		0
Foreign Currency [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gains (Losses)	$ (887)		$ 0

Accrued Expenses and Other Cu85

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 15, 2015	Dec. 31, 2014
Accrued Expenses and Other Current Liabilities [Abstract]
Payroll and employee benefits	$ 58,423		$ 73,362
Taxes other than income taxes	104,755		114,598
Interest	119,785	$ 90,000	30,384
Acquired sales contracts	3,852		12,453
Workers’ compensation	16,875		16,714
Asset retirement obligations	13,795		19,222
Other	11,965		35,663
Accrued Liabilities, Current	$ 329,450		$ 302,396

Accrued Expenses and Other Cu86

Accrued Expenses and Other Current Liabilities (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 15, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Grace period	30 days
Interest	$ 119,785	$ 90,000	$ 30,384
9.875% Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Senior notes interest rate	9.875%
7.00% Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Senior notes interest rate	7.00%
7.25% Senior Notes Due 2021 [Member]
Debt Instrument [Line Items]
Senior notes interest rate	7.25%

Debt and Financing Arrangemen87

Debt and Financing Arrangements (Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Other	$ 47,134	$ 56,031
Total	5,138,163	5,160,370
Current maturities of debt	5,107,210	36,885
Long-term debt	30,953	5,123,485
Loans Payable [Member]
Debt Instrument [Line Items]
Term loan due 2018 ($1.9 billion and $1.93 billion face value, respectively)	1,875,429	1,890,846
7.00% Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Senior notes	1,000,000	1,000,000
8.00% Senior Secured Notes due 2019 [Member]
Debt Instrument [Line Items]
Senior notes	350,000	350,000
9.875% Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Senior notes	365,600	363,493
7.25% Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Senior notes	500,000	500,000
7.25% Senior Notes Due 2021 [Member]
Debt Instrument [Line Items]
Senior notes	$ 1,000,000	$ 1,000,000

Debt and Financing Arrangemen88

Debt and Financing Arrangements (Narrative) (Details) - USD ($) $ in Thousands	Nov. 06, 2015	Dec. 17, 2013	Nov. 21, 2012	May. 12, 2012	Sep. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	May. 16, 2012	Jun. 14, 2011
Debt Instrument [Line Items]
Payments to retire debt		$ 628,700				$ 0	$ 300	$ 628,660
Principal amount of debt						5,158,258
Proceeds from term loan						0	0	294,000
Net loss resulting from early retirement of debt and debt restructuring		41,000				27,910	0	42,921
2,016						35,674
2,017						30,484
2,018						1,858,567
2,019						1,731,317
2,020						501,642
Thereafter						1,000,574
Payments of financing costs						0	4,519	$ 20,489
Professional Fees						$ 24,200
8.00% Senior Secured Notes due 2019 [Member]
Debt Instrument [Line Items]
Senior notes interest rate						8.00%
Senior notes						$ 350,000	350,000
Principal amount of debt		350,000
8.00% Senior Secured Notes due 2019 [Member] | Redeemable between January 15, 2016 and January 14, 2017 [Member]
Debt Instrument [Line Items]
Call premium						104.00%
8.00% Senior Secured Notes due 2019 [Member] | Redeemable between January 15, 2017 and January 14, 2018 [Member]
Debt Instrument [Line Items]
Call premium						102.00%
8.00% Senior Secured Notes due 2019 [Member] | Redeemable on or after January 15, 2018 [Member]
Debt Instrument [Line Items]
Call premium						100.00%
Line of Credit [Member]
Debt Instrument [Line Items]
Write off of deferred debt issuance cost						$ 3,700
Term Loan Due 2018 [Member]
Debt Instrument [Line Items]
Basis of variable spread (in percentage)						5.00%
Proceeds from term loan			$ 250,000	$ 1,400,000
Discount (premium) (percent)						1.00%
Payments on term loan		4,875			$ 3,500	$ 4,125
Balloon payment		1,800,000
Stated interest rate						1.25%
Loans Payable [Member]
Debt Instrument [Line Items]
Principal amount of debt		$ 300,000				$ 1,900,000	1,930,000
Discounted percentage of face amount		98.00%
9.875% Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Senior notes interest rate						9.875%
Senior notes						$ 365,600	363,493
Principal amount of debt						$ 375,000
Discount (premium) (percent)						95.934%
9.875% Senior Notes Due 2019 [Member] | Redeemable between December 15, 2016 and December 14, 2017 [Member]
Debt Instrument [Line Items]
Call premium						104.938%
9.875% Senior Notes Due 2019 [Member] | Redeemable between December 15, 2017 and December 14, 2018 [Member]
Debt Instrument [Line Items]
Call premium						102.469%
9.875% Senior Notes Due 2019 [Member] | On or after December 15, 2018 [Member]
Debt Instrument [Line Items]
Call premium						100.00%
7.25% Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Senior notes interest rate						7.25%
Senior notes						$ 500,000	500,000
Principal amount of debt						$ 500,000
7.25% Senior Notes Due October 10, 2020 [Member] | Redeemable between October 1, 2015 and September 30, 2016 [Member]
Debt Instrument [Line Items]
Call premium						103.625%
7.25% Senior Notes Due October 10, 2020 [Member] | Redeemable between October 1, 2016 and September 30, 2017 [Member]
Debt Instrument [Line Items]
Call premium						102.417%
7.25% Senior Notes Due October 10, 2020 [Member] | Redeemable between October 1, 2017 and September 30, 2018 [Member]
Debt Instrument [Line Items]
Call premium						101.208%
7.25% Senior Notes Due October 10, 2020 [Member] | Redeemable on or after October 1, 2018 [Member]
Debt Instrument [Line Items]
Call premium						100.00%
7.00% Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Principal amount of debt											$ 1,000,000
7.00% Senior Notes Due 2019 [Member] | Redeemable between June 15, 2015 and June 14, 2016 [Member]
Debt Instrument [Line Items]
Call premium						103.50%
7.00% Senior Notes Due 2019 [Member] | Redeemable between June 15, 2016 and June 14, 2017 [Member]
Debt Instrument [Line Items]
Call premium						101.75%
7.00% Senior Notes Due 2019 [Member] | June 15, 2017 and Beyond [Member]
Debt Instrument [Line Items]
Call premium						100.00%
7.00% Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Senior notes interest rate						7.00%
Senior notes						$ 1,000,000	1,000,000
7.25% Senior Notes Due 2021 [Member]
Debt Instrument [Line Items]
Senior notes interest rate						7.25%
Senior notes						$ 1,000,000	$ 1,000,000
7.25% Senior Notes Due 2021 [Member]
Debt Instrument [Line Items]
Principal amount of debt											$ 1,000,000
7.25% Senior Notes Due 2021 [Member] | Redeemable between June 15, 2016 and June 14, 2017 [Member]
Debt Instrument [Line Items]
Call premium						103.625%
7.25% Senior Notes Due 2021 [Member] | Redeemable between June 15, 2017 and June 14, 2018 [Member]
Debt Instrument [Line Items]
Call premium						102.417%
7.25% Senior Notes Due 2021 [Member] | Redeemable between June 15, 2018 and June 14, 2019 [Member]
Debt Instrument [Line Items]
Call premium						101.208%
7.25% Senior Notes Due 2021 [Member] | June 15, 2019 and Beyond [Member]
Debt Instrument [Line Items]
Call premium						100.00%
Secured Debt [Member] | 6.75% Senior Notes Due 2013 [Member]
Debt Instrument [Line Items]
Principal amount of debt										$ 450,000
Unsecured Debt [Member] | 8.75% senior unsecured notes [Member]
Debt Instrument [Line Items]
Principal amount of debt		$ 600,000
Revolving Credit Facility [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Termination notice period	5 days
Borrowings outstanding									$ 0

Taxes (Schedule of Components o

Taxes (Schedule of Components of Income Tax) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current:
Federal	$ 0	$ 0	$ 0
State	3	25	(647)
Total current	3	25	(647)
Deferred:
Federal	(329,393)	18,535	(318,956)
State	(43,990)	7,074	(15,895)
Total deferred	(373,383)	25,609	(334,851)
Provision for (benefit from) income taxes	$ (373,380)	$ 25,634	$ (335,498)

Taxes (Schedule of Effective In

Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Income tax provision (benefit) at statutory rate	$ (1,150,283)	$ (186,452)	$ (378,463)
Percentage depletion allowance	(19,035)	(12,692)	(15,796)
Goodwill	0	0	70,301
State taxes, net of effect of federal taxes	(76,445)	(3,903)	(25,265)
Change in valuation allowance	865,146	226,929	8,659
Other, net	7,237	1,752	5,066
Provision for (benefit from) income taxes	$ (373,380)	$ 25,634	$ (335,498)

Taxes (Schedule of Deferred Tax

Taxes (Schedule of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 1,086,332	$ 871,848
Alternative minimum tax credit carryforwards	120,994	127,169
Reclamation and mine closure	121,276	114,430
Goodwill	38,671	50,072
Workers' compensation	42,835	38,924
Share based compensation	22,612	30,283
Acquired sales contracts	17,466	26,833
Retiree benefit plans	16,996	22,913
Contract obligations	0	15,693
Advance royalties	18,751	0
Losses from disposed operations resulting from Patriot Coal bankruptcy	39,287	0
Other, primarily accrued liabilities	45,303	64,503
Gross deferred tax assets	1,570,523	1,362,668
Valuation allowance	(1,135,399)	(270,251)
Total deferred tax assets	435,124	1,092,417
Plant and equipment	389,169	1,354,396
Deferred development	41,047	95,129
Investment in tax partnerships	0	7,377
Other	4,706	5,533
Total deferred tax liabilities	434,922	1,462,435
Net deferred (asset) liability		$ 370,018
Net deferred (asset) liability	$ (202)

Taxes (Schedule of Gross Unreco

Taxes (Schedule of Gross Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning Balance	$ 34,709	$ 31,789	$ 31,150
Additions based on tax positions related to the current year	4,168	2,920	1,199
Additions for tax positions of prior years			688
Reductions as a result of lapses in the statute of limitations	0		(1,248)
Ending Balance	$ 38,877	$ 34,709	$ 31,789

Taxes (Narrative) (Details)

Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Stock options and other equity based compensation, tax expense (benefit)					$ 6,700	$ 1,600	$ 1,500
Operating loss carryforwards					3,000,000
Alternative minimum tax credit carryforwards	$ 127,169				120,994	127,169
Increase (decrease) in valuation allowance	807,200	$ 15,800	$ 18,300	$ 23,800	865,100	226,900	8,700
Interest and penalties accrued related to unrecognized tax benefits	$ 1,500				1,700	$ 1,500
Reductions as a result of lapses in the statute of limitations					$ 0		$ 1,248

Asset Retirement Obligations (N

Asset Retirement Obligations (Narrative) (Details) $ in Millions	Dec. 31, 2015USD ($)
asset retirement obligations [Line Items]
Letters of credit outstanding	$ 11.2
Asset retirement obligations [Member]
asset retirement obligations [Line Items]
Self-bonding obligations	485.5
Asset retirement obligations [Member]
asset retirement obligations [Line Items]
Surety bonds outstanding	$ 155.3

Asset Retirement Obligations (S

Asset Retirement Obligations (Schedule of Asset Retirement Obligations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	$ 418,118	$ 427,653
Accretion expense	33,680	32,909
Obligations incurred or acquired	(334)	(30,684)
Adjustments to the liability from changes in estimates	(28,570)	627
Liabilities settled	(12,440)	(12,387)
Ending Balance	410,454	418,118
Current portion included in accrued expenses	(13,795)	(19,222)
Noncurrent liability	$ 396,659	$ 398,896

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of senior notes and other long-term debt, including amounts classified as current	$ 937.1	$ 2,700
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net unrealized losses related to level 3 financial instruments	$ 2.7

Fair Value Measurements (Summar

Fair Value Measurements (Summary of Financial Assets and Liabilities Accounted for at Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets:
Investments in marketable securities	$ 201,910	$ 254,099
Derivatives	9,052	13,557
Total assets	210,962	267,656
Liabilities:
Derivatives	0	766
Level 1 [Member]
Assets:
Investments in marketable securities	11,713	5,145
Derivatives	5,597	9,026
Total assets	17,310	14,171
Level 2 [Member]
Assets:
Investments in marketable securities	190,197	248,954
Derivatives	1,023	1,491
Total assets	191,220	250,445
Liabilities:
Derivatives	0	766
Level 3 [Member]
Assets:
Derivatives	2,432	3,040
Total assets	2,432	3,040
Liabilities:
Derivatives	$ 0	$ 0

Fair Value Measurements (Summ98

Fair Value Measurements (Summary of Change in the Fair Values of Financial Instruments Categorized as Level 3) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 3,040	$ 4,946
Realized and unrealized losses recognized in earnings, net	(8,602)	(6,572)
Included in other comprehensive income	(1,341)	0
Purchases	13,541	5,288
Issuances	(4,046)	(622)
Settlements	(160)	0
Ending balance	$ 2,432	$ 3,040

Capital Stock (Narrative) (Deta

Capital Stock (Narrative) (Details)	Aug. 04, 2015	Dec. 31, 2015shares
Capital Stock [Abstract]
Reverse stock split conversion ratio	0.1
Stock repurchase authorized number		1,400,000
Outstanding shares available for repurchase		1,092,580

Stock-Based Compensation and100

Stock-Based Compensation and Other Incentive Plans (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for incentive plan	3.1
Number of shares available for grant	1
Unvested options weighted average grant date fair value (in dollars per share)	$ 35.47
Options vested in period fair value	$ 3.8	$ 8.7	$ 8.9
Stock options compensation expense	1.4	3.2	6.7
Unrecognized compensation cost	0.2
Share-based compensation expense	$ 5.9	5.6	5
Participants maximum deferred amount in base salaries percentage	85.00%
Participants maximum deferred amount in annual incentive awards percentage	100.00%
Participants maximum deferred stock awards percentage	100.00%
Net cash surrender values	$ 14.3	37.6
Deferred compensation plan liability	19.5	35.1
Net income (expense) related to deferred compensation plan	$ (0.9)	1.6	2.6
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
long term incentive plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period	3 years
Compensation expense	$ 7.9	10.1	$ 9.1
Amounts unpaid under long term incentive plan	$ 17.8	$ 21.1

Stock-Based Compensation and101

Stock-Based Compensation and Other Incentive Plans (Schedule of Stock Option Activity Under Incentive Plan) (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)$ / sharesshares
Common Shares
Options outstanding at beginning of period	682
Cancelled, Common Shares	(17)
Expired, Common Shares	(10)
Options outstanding at end of period	655
Weighted Average Exercise Price
Options outstanding at beginning of period (in dollars per share) | $ / shares	$ 198.41
Canceled (in dollars per share) | $ / shares	151.72
Expired (in dollars per share) | $ / shares	300.62
Options outstanding at end of period (in dollars per share) | $ / shares	$ 198.15
Options exercisable at period end	488
Options exercisable at end of period weighted average exercise price (in dollars per share) | $ / shares	$ 213
Options outstanding at end of period aggregate intrinsic value | $	$ 0
Options exercisable at end of period aggregate intrinsic value | $	$ 0
Options outstanding at end of period average remaining life	4 years 7 months 6 days
Options exercisable at end of period average remaining life	4 years 4 months 24 days
Unvested options at end of period	167

Stock-Based Compensation and102

Stock-Based Compensation and Other Incentive Plans (Schedule of Weighted Average Assumptions Used in Option Pricing) (Details)	12 Months Ended
	Dec. 31, 2015$ / shares
Share-based Compensation [Abstract]
Weighted average grant-date fair value per share of options granted (in dollars per share)	$ 23.70
Option, weighted average risk free rate	0.65%
Option, weighted average dividend yield	2.30%
Option, weighted average volatility	66.70%
Expected life of options (Years)	4 years 6 months

Stock-Based Compensation and103

Stock-Based Compensation and Other Incentive Plans (Restricted Stock and Restricted Stock Unit Activity and Weighted Average Grant-Date Fair Value) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2015$ / sharesshares
Restricted Stock [Member]
Restricted Stock Common Shares
Outstanding at beginning of period | shares	2
Granted | shares	0
Vested | shares	(2)
Canceled | shares	0
Outstanding at end of period | shares	0
Weighted Average Grant Date Fair Value
Outstanding weighted average grant date fair value at beginning of period | $ / shares	$ 134.42
Granted (in dollars per share) | $ / shares	0
Vested (in dollars per share) | $ / shares	$ 134.42
Canceled (in dollars per share) | $ / shares	0
Outstanding weighted average grant date fair value at end of period | $ / shares	$ 0
Restricted Stock Units (RSUs) [Member]
Restricted Stock Common Shares
Outstanding at beginning of period | shares	307
Granted | shares	169
Vested | shares	(66)
Canceled | shares	(21)
Outstanding at end of period | shares	389
Weighted Average Grant Date Fair Value
Outstanding weighted average grant date fair value at beginning of period | $ / shares	$ 60.53
Granted (in dollars per share) | $ / shares	12.84
Vested (in dollars per share) | $ / shares	$ 104.90
Canceled (in dollars per share) | $ / shares	35.81
Outstanding weighted average grant date fair value at end of period | $ / shares	$ 33.69

Workers' Compensation Expens104

Workers' Compensation Expense (Worker's Compensation Expense) (Details) - Workers' Compensation [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accrued Workers' Compensation [Line Items]
Total net benefit	$ 15,199	$ 4,432	$ 6,137
Traumatic injury claims and assessments	16,781	19,924	21,089
Total workers’ compensation expense	31,980	$ 24,356	$ 27,226
Surety bonds and letters of credit outstanding	$ 148,200

Workers' Compensation Expens105

Workers' Compensation Expense (Schedule of Amounts Recognized in Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Workers' Compensation [Line Items]
Total obligations	$ 129,145	$ 111,005
Less amount included in accrued expenses	16,875	16,714
Noncurrent obligations	112,270	94,291
Occupational Disease [Member]
Accrued Workers' Compensation [Line Items]
Occupational disease costs	90,836	72,749
Workers' Compensation [Member]
Accrued Workers' Compensation [Line Items]
Occupational disease costs	$ 38,309	$ 38,256

Employee Benefit Plans (Narrati

Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation of pension plans	$ 301.3	$ 353.7
Health care cost trend rate assumed	7.10%
Ultimate trend rate	4.50%
Effect of one percentage point increase on postretirement benefit obligation	$ 9.4
Effect of one percentage point increase on postretirement benefit cost	0.1
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Amount invested by plan	$ 16
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations (percent)	60.00%
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations (percent)	40.00%
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of net gains (losses)	$ (3)
Pension Contributions	0.5
Other postretirement benefits payments	20.5	$ 22.9	$ 25.1
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Amortization of net gains (losses)	2.3
Amortization of net prior service cost	$ 10.7

Employee Benefit Plans (Schedul

Employee Benefit Plans (Schedule of Defined Benefit Plans Disclosures) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Value of Plan Assets at beginning of year	$ 336,709
Value of Plan Assets at end of year		$ 336,709
Pension Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligations at beginning of year	353,736	355,468
Service cost	9	21,478	$ 27,065
Interest cost	14,604	17,070	16,207
Re-entry of former Magnum employees	0	0
Plan amendments	0	(23)
Curtailments	0	(25,787)
Benefits paid	(61,955)	(53,974)
Other-primarily actuarial loss (gain)	(5,102)	39,504
Benefit Obligations at end of year	301,292	353,736	355,468
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Value of Plan Assets at beginning of year	336,709	347,952
Actual return on plan assets	(1,679)	36,130
Employer contributions	424	6,601
Benefits paid	(61,955)	(53,974)
Value of Plan Assets at end of year	273,499	336,709	347,952
Accrued benefit cost	(27,793)	(17,027)
Prior service credit (cost)	0	0
Accumulated gain (loss)	16,769	11,332
Total not yet recognized as a component of net periodic benefit cost	(16,769)	(11,332)
Current liability	(420)	(767)
Noncurrent liability	(27,373)	(16,260)
Pension and Other Postretirement Defined Benefit Plans, Liabilities	(27,793)	(17,027)
Other Postretirement Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligations at beginning of year	36,098	42,531
Service cost	866	1,649	2,027
Interest cost	1,904	1,841	1,739
Re-entry of former Magnum employees	85,843	0
Plan amendments	0	0
Curtailments	0	0
Benefits paid	(3,646)	(3,431)
Other-primarily actuarial loss (gain)	(17,605)	(6,492)
Benefit Obligations at end of year	103,460	36,098	42,531
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Value of Plan Assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	3,646	3,431
Benefits paid	(3,646)	(3,431)
Value of Plan Assets at end of year	0	0	$ 0
Accrued benefit cost	(103,460)	(36,098)
Prior service credit (cost)	26,944	21,972
Accumulated gain (loss)	(11,313)	(9,125)
Total not yet recognized as a component of net periodic benefit cost	38,257	31,097
Current liability	(3,650)	(3,430)
Noncurrent liability	(99,810)	(32,668)
Pension and Other Postretirement Defined Benefit Plans, Liabilities	$ (103,460)	$ (36,098)

Employee Benefit Plans (Sche108

Employee Benefit Plans (Schedule of Net Benefit Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 9	$ 21,478	$ 27,065
Interest cost	14,604	17,070	16,207
Curtailments	0	(25,368)	47
Settlements	2,656	646	0
Expected return on plan assets	(20,367)	(23,756)	(23,761)
Amortization of prior service credits	0	(257)	(204)
Amortization of other actuarial losses	8,850	3,128	14,616
Total net benefit	5,752	(7,059)	33,970
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	866	1,649	2,027
Interest cost	1,904	1,841	1,739
Curtailments		0	(5,444)
Settlements	0	0	0
Expected return on plan assets	0	0	0
Amortization of prior service credits	(8,335)	(10,003)	(10,621)
Amortization of other actuarial losses	(2,109)	(761)	(252)
Total net benefit	$ (7,674)	$ (7,274)	$ (12,551)

Employee Benefit Plans (Sche109

Employee Benefit Plans (Schedule of Assumptions Used to Calculate Benefit Obligations) (Details)	Dec. 31, 2015	Dec. 31, 2014
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.59%	4.15%
Other Postretirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.57%	3.91%

Employee Benefit Plans (Sche110

Employee Benefit Plans (Schedule of Assumptions Used) (Details)	3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013	Jun. 30, 2014	Sep. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.14%	4.23%	5.05%	5.08%	4.13%	4.15%
Rate of compensation increase								3.39%
Expected return on plan assets						7.00%	7.75%	7.75%
Other Postretirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate			4.58%		3.64%	3.91%	4.58%

Employee Benefit Plans (Sche111

Employee Benefit Plans (Schedule of Allocation of Plan Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets		$ 336,709
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	$ 74,051	89,982
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	180,813	228,657
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	18,635	18,070
U.S. Small-Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	11,640	16,512
U.S. Small-Cap [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	11,640	16,512
U.S. Mid-Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	28,524	46,481
U.S. Mid-Cap [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	10,979	17,301
U.S. Mid-Cap [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	17,545	29,180
U.S. Large-Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	67,244	89,008
U.S. Large-Cap [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	33,249	43,181
U.S. Large-Cap [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	33,995	45,827
Non-U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	18,785	25,905
Non-U.S. [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	18,785	25,905
U.S. Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	18,844	13,708
U.S. Government Securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	18,183	12,988
U.S. Government Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	661	720
Non-U.S. Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	766	1,599
Non-U.S. Government Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	766	1,599
U.S. governement asset and mortgage backed securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	1,056	830
U.S. governement asset and mortgage backed securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	1,056	830
Corporate fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	39,939	22,702
Corporate fixed income [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	39,939	22,702
State and Local Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	5,725	8,005
State and Local Government Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	5,725	8,005
Other fixed income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	57,209	83,735
Other fixed income [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	57,209	83,735
Short-term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	3,898	6,818
Short-term Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	3,898	6,818
Other Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	19,869	21,406
Other Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	1,234	3,336
Other Investments [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan assets	$ 18,635	$ 18,070

Employee Benefit Plans (Summary

Employee Benefit Plans (Summary of Estimated Future Benefit Payments) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2,016	$ 19,164
2,107	20,320
2,018	21,833
2,019	21,341
2,020	21,461
Thereafter	106,953
Total	211,072
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2,016	8,356
2,107	8,341
2,018	8,344
2,019	8,281
2,020	8,245
Thereafter	38,178
Total	$ 79,745

Loss Per Common Share (Narrativ

Loss Per Common Share (Narrative) (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive due to price [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of options to purchase common stock	1	0.8	0.8

Leases (Narrative) (Details)

Leases (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
lease payments [Line Items]
Capital Lease Obligations	$ 40	$ 46
Rental expense	28.4	42.1	$ 42.1
Royalty expense	227.7	$ 242.5	$ 261.1
lease [Member]
lease payments [Line Items]
Surety bonds outstanding	$ 49.4

Leases (Schedule of Lease Minim

Leases (Schedule of Lease Minimum Payments) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Property Subject to Operating Lease [Member]
lease payments [Line Items]
2,016	$ 20,857
2,017	17,277
2,018	6,412
2,019	3,448
2,020	2,151
Thereafter	9,807
Operating Leases, Future Minimum Payments Due	59,952
Royalty Agreements [Member]
lease payments [Line Items]
2,016	8,947
2,017	13,991
2,018	13,097
2,019	12,295
2,020	11,996
Thereafter	103,771
Operating Leases, Future Minimum Payments Due	$ 164,097

Risk Concentrations (Narrative)

Risk Concentrations (Narrative) (Details) $ in Thousands, T in Millions	12 Months Ended
	Dec. 31, 2015USD ($)T	Dec. 31, 2014USD ($)
Concentration Risk [Line Items]
Receivables	$ 135,767	$ 232,017
Trade accounts receivable (net of allowance for doubtful accounts of $7.8 million and $0.2 million, respectively)	$ 117,405	211,506
Tons of coal sold | T	127.6
Percentage of tons sold under long term contract	68.00%
Long term contracts percentage of company revenue	55.00%
Long-term contracts, life term, minimum	1 year
Long-term contracts, life term, maximum	5 years
Electric Utilities [Member]
Concentration Risk [Line Items]
Receivables	$ 83,800	$ 134,700
Percentage of total trade accounts receivable	72.00%	64.00%
Domestic And Foreign Steel Producers [Member]
Concentration Risk [Line Items]
Trade accounts receivable (net of allowance for doubtful accounts of $7.8 million and $0.2 million, respectively)	$ 32,800	$ 76,000
Trade receivables, percentage	28.00%	36.00%

Risk Concentrations (Schedule o

Risk Concentrations (Schedule of Foreign Revenues) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
foreign revenue [Line Items]
Sales to customers in foreign countries	$ 395,323	$ 611,917	$ 822,024
Europe [Member]
foreign revenue [Line Items]
Sales to customers in foreign countries	170,314	277,565	371,363
Asia [Member]
foreign revenue [Line Items]
Sales to customers in foreign countries	96,523	156,057	160,404
North America [Member]
foreign revenue [Line Items]
Sales to customers in foreign countries	40,315	78,445	80,322
Central and South America [Member]
foreign revenue [Line Items]
Sales to customers in foreign countries	55,323	20,496	55,493
Brokered Sales [Member]
foreign revenue [Line Items]
Sales to customers in foreign countries	$ 32,848	$ 79,354	$ 154,442

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	Apr. 06, 2015	Feb. 16, 2015	Aug. 25, 2011	May. 02, 2011	Apr. 30, 2015	Jul. 31, 2013	Feb. 01, 2011	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Aug. 13, 2007
Loss Contingencies [Line Items]
Purchase replacement coal											$ 100
Litigation settlement		$ 7.5	$ 104.1	$ 104.1
Past damages				13.8
Future damages				$ 90.3
Payments for legal settlements					$ 2.8
Amount accrued								$ 2.8	$ 22.3
Amount accrued current portion								2.8	10.1
2,016								94.6
2,017								25.4
2,018								10.6
2,019								11.3
2,020								11.6
Thereafter								11.1
Transportation capacity agreements								$ 52.9	$ 36.5	$ 12
Minimum [Member]
Loss Contingencies [Line Items]
Aggregate amount of past and future damages							$ 228
Maximum [Member]
Loss Contingencies [Line Items]
Aggregate amount of past and future damages							$ 377
Subsidiaries [Member]
Loss Contingencies [Line Items]
Litigation settlement	$ 15
Judicial Ruling [Member]
Loss Contingencies [Line Items]
Payments for legal settlements						$ 15.6

Subsequent Events (Details)

Subsequent Events (Details) T in Millions	Jan. 21, 2016USD ($)factordraw	Jan. 10, 2016USD ($)	Dec. 31, 2015USD ($)T
Subsequent Event [Line Items]
Account receivable securitization, program fees (percentage)			2.65%
Subsequent Event [Member]
Subsequent Event [Line Items]
Holder's of first lien term loan, percentage		50.00%
Stock outstanding, subject to dilution, percentage		100.00%
Reduction to long term debt		$ 4,500,000,000
Securitized account receivable	$ 200,000,000
Number of factors required to determine cost of advance backstopping a letter of credit issued under the securitization facility | factor	2
DIP, amount arranged	$ 275,000,000
DIP, amount arranged, number of withdrawals allowed | draw	2
DIP, amount arranged, period of availability (in months)	6 months
DIP, carve-out for claims	$ 75,000,000
DIP, financial maintenance covenant, prior to entry of final order	300,000,000
DIP, financial maintenance covenant, following the entry of final order	500,000,000
DIP, customary prepayments, proceeds from sale or disposition of non-ordinary course asset	50,000,000
DIP, Customary Prepayments, Proceeds from Sale or Disposition of Non-Ordinary Course Asset, Individual Sale, Maximum	7,500,000
DIP, Customary prepayments, proceeds from any casualty event	$ 50,000,000
Base Rate [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Basis of variable spread (in percentage)	8.00%
LLIBOR [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Basis of variable spread (in percentage)	9.00%
7.00% Senior Notes Due 2019 [Member]
Subsequent Event [Line Items]
Senior notes interest rate			7.00%
9.875% Senior Notes Due 2019 [Member]
Subsequent Event [Line Items]
Senior notes interest rate			9.875%
8.00% Senior Secured Notes due 2019 [Member]
Subsequent Event [Line Items]
Senior notes interest rate			8.00%
7.25% Senior Notes Due 2020 [Member]
Subsequent Event [Line Items]
Senior notes interest rate			7.25%
7.25% Senior Notes Due 2021 [Member]
Subsequent Event [Line Items]
Senior notes interest rate			7.25%
Amount to be settled in cash			$ 326,500,000
Interest Rate Floor [Member] | LLIBOR [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Basis of variable spread (in percentage)	1.00%
Kentucky [Member]
Subsequent Event [Line Items]
Net book value of idled facility			$ 66,800,000
Amount of reserves (tons) | T			22

Segment Information (Schedule o

Segment Information (Schedule of Operating Segment Results) (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
Segment Reporting Information [Line Items]
Revenues	$ 563,249	$ 688,544	$ 644,462	$ 677,005	$ 745,192	$ 742,180	$ 713,776	$ 735,971	$ 2,573,260	$ 2,937,119	$ 3,014,357
Adjusted EBITDA									250,117	280,143	252,146
Depreciation, depletion and amortization									379,345	418,748	426,442
Amortization of acquired sales contracts, net									(8,811)	(13,187)	(9,457)
Total assets	5,106,738				8,429,723				5,106,738	8,429,723	8,990,193
Capital expenditures									119,024	147,286	296,984
Operating Segments [Member] | PRB [Member]
Segment Reporting Information [Line Items]
Revenues									1,448,440	1,490,377	1,482,812
Adjusted EBITDA									258,300	198,074	206,910
Depreciation, depletion and amortization									176,257	168,522	171,324
Amortization of acquired sales contracts, net									(4,158)	(3,961)	(3,656)
Total assets	1,648,916				1,772,230				1,648,916	1,772,230	1,841,835
Capital expenditures									22,535	44,305	9,784
Operating Segments [Member] | APP [Member]
Segment Reporting Information [Line Items]
Revenues									834,606	1,108,358	1,145,801
Adjusted EBITDA									82,837	110,693	88,883
Depreciation, depletion and amortization									156,273	205,732	202,952
Amortization of acquired sales contracts, net									(4,653)	(9,433)	(10,364)
Total assets	843,583				3,379,834				843,583	3,379,834	3,971,764
Capital expenditures									20,599	23,638	167,759
Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Revenues									290,214	338,384	385,744
Adjusted EBITDA									17,044	56,612	94,948
Depreciation, depletion and amortization									40,768	40,125	45,741
Amortization of acquired sales contracts, net									0	207	4,563
Total assets	310,949				339,809				310,949	339,809	402,922
Capital expenditures									11,135	12,993	23,122
Corporate, Other and Elimination
Segment Reporting Information [Line Items]
Adjusted EBITDA									(108,064)	(85,236)	(138,595)
Depreciation, depletion and amortization									6,047	4,369	6,425
Amortization of acquired sales contracts, net									0	0	0
Total assets	$ 2,303,290				$ 2,937,850				2,303,290	2,937,850	2,773,672
Capital expenditures									$ 64,755	$ 66,350	$ 96,319

Segment Information (Reconcilia

Segment Information (Reconciliation of Segment Income from Operations to Consolidated Income Before Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended								6 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, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting [Abstract]
Adjusted EBITDA										$ 250,117	$ 280,143	$ 252,146
Depreciation, depletion and amortization										(379,345)	(418,748)	(426,442)
Amortization of acquired sales contracts, net										8,811	13,187	9,457
Asset impairment costs	$ (488,865)	$ (2,120,292)	$ (19,146)	$ 0	$ (17,541)	$ (5,060)	$ (1,512)	$ 0	$ (2,600,000)	(2,628,303)	(24,113)	(220,879)
Goodwill impairment										0	0	(265,423)
Losses from disposed operations resulting from Patriot Coal bankruptcy										(116,343)	0	0
Settlement of UMWA legal claims										0	0	(12,000)
Interest expense, net										(393,549)	(383,188)	(374,664)
Nonoperating expense										(27,910)	0	(42,921)
Loss from continuing operations before income taxes										$ (3,286,522)	$ (532,719)	$ (1,080,726)

Quarterly Selected Financial122

Quarterly Selected Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								6 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, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 563,249	$ 688,544	$ 644,462	$ 677,005	$ 745,192	$ 742,180	$ 713,776	$ 735,971		$ 2,573,260	$ 2,937,119	$ 3,014,357
Gross profit (loss)	(44,964)	47,275	(16,507)	14,256	32,264	(5,851)	(6,350)	(49,842)
Asset impairment and mine closure costs	488,865	2,120,292	19,146	0	17,541	5,060	1,512	0	$ 2,600,000	2,628,303	24,113	220,879
Loss from operations	(539,033)	(2,236,772)	(69,546)	(19,712)	(5,303)	(35,300)	(35,805)	(73,123)		(2,865,063)	(149,531)	(663,141)
Net loss	$ (632,368)	$ (1,999,476)	$ (168,103)	$ (113,195)	$ (240,135)	$ (97,218)	$ (96,860)	$ (124,140)		(2,913,142)	(558,353)	(641,832)
Diluted loss per common share (in dollars per share)	$ (29.70)	$ (93.91)	$ (7.93)	$ (5.32)	$ (11.31)	$ (4.58)	$ (4.57)	$ (5.85)
Increase (decrease) in valuation allowance					$ 807,200	$ 15,800	$ 18,300	$ 23,800		$ 865,100	$ 226,900	$ 8,700

Supplemental Consolidating F123

Supplemental Consolidating Financial Information (Schedule of Consolidating Statements of Operations) (Details) - USD ($) $ in Thousands	Dec. 17, 2013	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, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Income Statements, Captions [Line Items]
Revenues		$ 563,249	$ 688,544	$ 644,462	$ 677,005	$ 745,192	$ 742,180	$ 713,776	$ 735,971		$ 2,573,260	$ 2,937,119	$ 3,014,357
Costs, expenses and other
Cost of sales (exclusive of items shown separately below)											2,206,433	2,566,193	2,663,136
Depreciation, depletion and amortization											379,345	418,748	426,442
Amortization of acquired sales contracts, net											(8,811)	(13,187)	(9,457)
Change in fair value of coal derivatives and coal trading activities, net											(1,583)	(3,686)	7,845
Asset impairment and mine closure costs		488,865	2,120,292	19,146	0	17,541	5,060	1,512	0	$ 2,600,000	2,628,303	24,113	220,879
Losses from disposed operations resulting from Patriot Coal bankruptcy											116,343	0	0
Goodwill impairment											0	0	265,423
Selling, general and administrative expenses											98,783	114,223	133,448
Other operating expense (income), net											19,510	(19,754)	(30,218)
Total operating expenses											5,438,323	3,086,650	3,677,498
Loss from investment in subsidiaries											0	0	0
Loss from operations		(539,033)	(2,236,772)	(69,546)	(19,712)	(5,303)	(35,300)	(35,805)	(73,123)		(2,865,063)	(149,531)	(663,141)
Interest expense, net
Interest expense											(397,979)	(390,946)	(381,267)
Interest and investment income											4,430	7,758	6,603
Interest expense, net											(393,549)	(383,188)	(374,664)
Other Nonoperating Income (Expense) [Abstract]
Net loss resulting from early retirement of debt and debt restructuring	$ 41,000										27,910	0	42,921
Loss from continuing operations before income taxes											(3,286,522)	(532,719)	(1,080,726)
Provision for (benefit from) income taxes											373,380	(25,634)	335,498
Loss from continuing operations											(2,913,142)	(558,353)	(745,228)
Income from discontinued operations, including gain on sale - net of tax											0	0	(103,396)
Net loss		$ (632,368)	$ (1,999,476)	$ (168,103)	$ (113,195)	$ (240,135)	$ (97,218)	$ (96,860)	$ (124,140)		(2,913,142)	(558,353)	(641,832)
Total comprehensive income (loss)											(2,918,198)	(592,804)	(587,633)
Parent/Issuer [Member]
Condensed Income Statements, Captions [Line Items]
Revenues											0	0	0
Costs, expenses and other
Cost of sales (exclusive of items shown separately below)											22,378	3,016	9,117
Depreciation, depletion and amortization											3,775	5,154	5,949
Amortization of acquired sales contracts, net											0	0	0
Change in fair value of coal derivatives and coal trading activities, net											0	0	0
Asset impairment and mine closure costs											15,437	3,642	78,150
Losses from disposed operations resulting from Patriot Coal bankruptcy											116,343
Goodwill impairment													0
Selling, general and administrative expenses											69,384	79,902	88,820
Other operating expense (income), net											5,869	(4,480)	4,209
Total operating expenses											233,186	87,234	186,245
Loss from investment in subsidiaries											(2,574,565)	(13,085)	(328,889)
Loss from operations											(2,807,751)	(100,319)	(515,134)
Interest expense, net
Interest expense											(478,432)	(463,823)	(449,614)
Interest and investment income											27,510	31,389	30,285
Interest expense, net											(450,922)	(432,434)	(419,329)
Other Nonoperating Income (Expense) [Abstract]
Net loss resulting from early retirement of debt and debt restructuring											27,910		42,921
Loss from continuing operations before income taxes											(3,286,583)	(532,753)	(977,384)
Provision for (benefit from) income taxes											373,441	(25,600)	335,552
Loss from continuing operations													(641,832)
Income from discontinued operations, including gain on sale - net of tax													0
Net loss											(2,913,142)	(558,353)	(641,832)
Total comprehensive income (loss)											(2,918,198)	(592,804)	(587,633)
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Revenues											2,573,260	2,937,119	3,014,357
Costs, expenses and other
Cost of sales (exclusive of items shown separately below)											2,186,804	2,566,572	2,657,583
Depreciation, depletion and amortization											375,568	413,559	420,458
Amortization of acquired sales contracts, net											(8,811)	(13,187)	(9,457)
Change in fair value of coal derivatives and coal trading activities, net											(1,583)	(3,686)	7,845
Asset impairment and mine closure costs											2,612,866	20,471	142,729
Losses from disposed operations resulting from Patriot Coal bankruptcy											0
Goodwill impairment													265,423
Selling, general and administrative expenses											25,737	29,739	39,825
Other operating expense (income), net											13,021	(15,726)	(34,856)
Total operating expenses											5,203,602	2,997,742	3,489,550
Loss from investment in subsidiaries											0	0	0
Loss from operations											(2,630,342)	(60,623)	(475,193)
Interest expense, net
Interest expense											(26,284)	(26,137)	(24,747)
Interest and investment income											82,881	74,511	68,248
Interest expense, net											56,597	48,374	43,501
Other Nonoperating Income (Expense) [Abstract]
Net loss resulting from early retirement of debt and debt restructuring											0		0
Loss from continuing operations before income taxes											(2,573,745)	(12,249)	(431,692)
Provision for (benefit from) income taxes											0	0	0
Loss from continuing operations													(431,692)
Income from discontinued operations, including gain on sale - net of tax													(103,396)
Net loss											(2,573,745)	(12,249)	(328,296)
Total comprehensive income (loss)											(2,579,601)	(34,439)	(304,278)
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Revenues											0	0	0
Costs, expenses and other
Cost of sales (exclusive of items shown separately below)											0	0	0
Depreciation, depletion and amortization											2	35	35
Amortization of acquired sales contracts, net											0	0	0
Change in fair value of coal derivatives and coal trading activities, net											0	0	0
Asset impairment and mine closure costs											0	0	0
Losses from disposed operations resulting from Patriot Coal bankruptcy											0
Goodwill impairment													0
Selling, general and administrative expenses											5,725	6,626	7,038
Other operating expense (income), net											(4,192)	(4,987)	(5,370)
Total operating expenses											1,535	1,674	1,703
Loss from investment in subsidiaries											0	0	0
Loss from operations											(1,535)	(1,674)	(1,703)
Interest expense, net
Interest expense											(4,916)	(4,259)	(4,214)
Interest and investment income											5,692	5,131	5,378
Interest expense, net											776	872	1,164
Other Nonoperating Income (Expense) [Abstract]
Net loss resulting from early retirement of debt and debt restructuring											0		0
Loss from continuing operations before income taxes											(759)	(802)	(539)
Provision for (benefit from) income taxes											(61)	(34)	(54)
Loss from continuing operations													(593)
Income from discontinued operations, including gain on sale - net of tax													0
Net loss											(820)	(836)	(593)
Total comprehensive income (loss)											(820)	(836)	(593)
Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Revenues											0	0	0
Costs, expenses and other
Cost of sales (exclusive of items shown separately below)											(2,749)	(3,395)	(3,564)
Depreciation, depletion and amortization											0	0	0
Amortization of acquired sales contracts, net											0	0	0
Change in fair value of coal derivatives and coal trading activities, net											0	0	0
Asset impairment and mine closure costs											0	0	0
Losses from disposed operations resulting from Patriot Coal bankruptcy											0
Goodwill impairment													0
Selling, general and administrative expenses											(2,063)	(2,044)	(2,235)
Other operating expense (income), net											4,812	5,439	5,799
Total operating expenses											0	0	0
Loss from investment in subsidiaries											2,574,565	13,085	328,889
Loss from operations											2,574,565	13,085	328,889
Interest expense, net
Interest expense											111,653	103,273	97,308
Interest and investment income											(111,653)	(103,273)	(97,308)
Interest expense, net											0	0	0
Other Nonoperating Income (Expense) [Abstract]
Net loss resulting from early retirement of debt and debt restructuring											0		0
Loss from continuing operations before income taxes											2,574,565	13,085	328,889
Provision for (benefit from) income taxes											0	0	0
Loss from continuing operations													328,889
Income from discontinued operations, including gain on sale - net of tax													0
Net loss											2,574,565	13,085	328,889
Total comprehensive income (loss)											$ 2,580,421	$ 35,275	$ 304,871

Supplemental Consolidating F124

Supplemental Consolidating Financial Information (Schedule of Consolidating Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets
Cash and cash equivalents	$ 450,781	$ 734,231	$ 911,099	$ 784,622
Short term investments	200,192	248,954
Restricted cash	97,542	5,678
Receivables	135,767	232,017
Inventories	196,720	190,253
Other	122,780	131,618
Total current assets	1,203,782	1,542,751
Property, plant and equipment, net	3,619,029	6,453,458
Investment in subsidiaries	0	0
Intercompany receivables	0	0
Note receivable from Arch Western	0	0
Other assets	283,927	433,514
Total assets	5,106,738	8,429,723	8,990,193
Liabilities and Stockholders’ Equity
Accounts payable	128,131	180,113
Accrued expenses and other current liabilities	329,450	302,396
Current maturities of debt	5,107,210	36,885
Total current liabilities	5,564,791	519,394
Long-term debt	30,953	5,123,485
Intercompany payables	0	0
Note payable to Arch Coal	0	0
Asset retirement obligations	396,659	398,896
Accrued pension benefits	27,373	16,260
Accrued postretirement benefits other than pension	99,810	32,668
Accrued workers’ compensation	112,270	94,291
Deferred income taxes	0	422,809
Other noncurrent liabilities	119,171	153,766
Total liabilities	6,351,027	6,761,569
Total stockholders’ equity (deficit)	(1,244,289)	1,668,154	2,253,249	2,854,567
Total liabilities and stockholders’ equity (deficit)	5,106,738	8,429,723
Parent/Issuer [Member]
Assets
Cash and cash equivalents	337,646	572,185	799,333	671,313
Short term investments	200,192	248,954
Restricted cash	0	0
Receivables	12,463	9,656
Inventories	0	0
Other	83,017	89,211
Total current assets	633,318	920,006
Property, plant and equipment, net	7,747	10,470
Investment in subsidiaries	4,887,905	$ 7,464,221
Intercompany receivables	0
Note receivable from Arch Western	675,000	$ 675,000
Other assets	39,302	131,884
Total assets	6,243,272	9,201,581
Liabilities and Stockholders’ Equity
Accounts payable	8,495	23,394
Accrued expenses and other current liabilities	162,268	85,899
Current maturities of debt	5,096,460	27,625
Total current liabilities	5,267,223	136,918
Long-term debt	0	5,084,839
Intercompany payables	2,043,308	1,817,755
Note payable to Arch Coal	0	0
Asset retirement obligations	1,005	981
Accrued pension benefits	12,390	5,967
Accrued postretirement benefits other than pension	79,826	4,430
Accrued workers’ compensation	24,247	9,172
Deferred income taxes	0	422,809
Other noncurrent liabilities	59,976	50,919
Total liabilities	7,487,975	7,533,790
Total stockholders’ equity (deficit)	(1,244,703)	1,667,791
Total liabilities and stockholders’ equity (deficit)	6,243,272	9,201,581
Guarantor Subsidiaries [Member]
Assets
Cash and cash equivalents	100,428	150,358	100,418	100,468
Short term investments	0	0
Restricted cash	0	0
Receivables	3,153	15,933
Inventories	196,720	190,253
Other	38,794	41,455
Total current assets	339,095	397,999
Property, plant and equipment, net	3,610,869	6,442,623
Investment in subsidiaries	0	0
Intercompany receivables	2,253,312	2,021,110
Note receivable from Arch Western	0	0
Other assets	243,806	300,058
Total assets	6,447,082	9,161,790
Liabilities and Stockholders’ Equity
Accounts payable	119,633	156,664
Accrued expenses and other current liabilities	170,575	220,017
Current maturities of debt	10,750	9,260
Total current liabilities	300,958	385,941
Long-term debt	30,953	38,646
Intercompany payables	0	0
Note payable to Arch Coal	675,000	675,000
Asset retirement obligations	395,654	397,915
Accrued pension benefits	14,983	10,293
Accrued postretirement benefits other than pension	19,984	28,238
Accrued workers’ compensation	88,023	85,119
Deferred income taxes	0	0
Other noncurrent liabilities	58,847	102,461
Total liabilities	1,584,402	1,723,613
Total stockholders’ equity (deficit)	4,862,680	7,438,177
Total liabilities and stockholders’ equity (deficit)	6,447,082	9,161,790
Non-Guarantor Subsidiaries [Member]
Assets
Cash and cash equivalents	12,707	11,688	11,348	12,841
Short term investments	0	0
Restricted cash	97,542	5,678
Receivables	124,581	211,043
Inventories	0
Other	969	952
Total current assets	235,799	229,361
Property, plant and equipment, net	0	2
Investment in subsidiaries	0	0
Intercompany receivables	0	0
Note receivable from Arch Western	0	0
Other assets	819	1,572
Total assets	236,618	230,935
Liabilities and Stockholders’ Equity
Accounts payable	3	55
Accrued expenses and other current liabilities	1,037	1,095
Current maturities of debt	0	0
Total current liabilities	1,040	1,150
Long-term debt	0	0
Intercompany payables	210,005	203,355
Note payable to Arch Coal	0	0
Asset retirement obligations	0	0
Accrued pension benefits	0	0
Accrued postretirement benefits other than pension	0	0
Accrued workers’ compensation	0	0
Deferred income taxes	0	0
Other noncurrent liabilities	348	386
Total liabilities	211,393	204,891
Total stockholders’ equity (deficit)	25,225	26,044
Total liabilities and stockholders’ equity (deficit)	236,618	230,935
Eliminations [Member]
Assets
Cash and cash equivalents	0	0	$ 0	$ 0
Short term investments	0	0
Restricted cash	0	0
Receivables	(4,430)	(4,615)
Inventories	0	0
Other	0	0
Total current assets	(4,430)	(4,615)
Property, plant and equipment, net	413	363
Investment in subsidiaries	(4,887,905)	(7,464,221)
Intercompany receivables	(2,253,312)	(2,021,110)
Note receivable from Arch Western	(675,000)	(675,000)
Other assets	0	0
Total assets	(7,820,234)	(10,164,583)
Liabilities and Stockholders’ Equity
Accounts payable	0	0
Accrued expenses and other current liabilities	(4,430)	(4,615)
Current maturities of debt	0	0
Total current liabilities	(4,430)	$ (4,615)
Long-term debt	0
Intercompany payables	(2,253,313)	$ (2,021,110)
Note payable to Arch Coal	(675,000)	(675,000)
Asset retirement obligations	0	0
Accrued pension benefits	0	0
Accrued postretirement benefits other than pension	0	0
Accrued workers’ compensation	0	0
Deferred income taxes	0	0
Other noncurrent liabilities	0	0
Total liabilities	(2,932,743)	(2,700,725)
Total stockholders’ equity (deficit)	(4,887,491)	(7,463,858)
Total liabilities and stockholders’ equity (deficit)	$ (7,820,234)	$ (10,164,583)

Supplemental Consolidating F125

Supplemental Consolidating Financial Information (Schedule of Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash provided by (used in) operating activities	$ (44,367)	$ (33,582)	$ 55,742
Investing Activities
Capital expenditures	(119,024)	(147,286)	(296,984)
Additions to prepaid royalties	(5,871)	(7,317)	(14,947)
Proceeds from disposals and divestitures	2,191	62,358	433,453
Proceeds from sale-leaseback transactions	0	0	34,919
Purchases of short term investments	(246,735)	(211,929)	(213,726)
Proceeds from sales of short term investments	290,205	205,611	194,537
Proceeds from sale of investments in equity investments and securities	2,259	9,464	0
Withdrawals (deposits) of restricted cash	(91,864)	(5,678)	3,453
Investments in and advances to affiliates, net	(11,502)	(16,657)	(15,260)
Cash provided by (used in) investing activities	(180,341)	(111,434)	125,445
Financing Activities
Contributions from parent			0
Proceeds from term loan and senior notes			644,000
Payments to retire debt			(628,660)
Payments on term loan	(19,500)	(19,500)	(17,250)
Net payments on other debt	(11,332)	(5,695)	(6,836)
Debt financing costs	0	(4,519)	(20,489)
Dividends paid	0	(2,123)	(25,475)
Other	0	(15)	0
Expenses related to debt restructuring	(27,910)	0	0
Transactions with affiliates, net	0	0	0
Cash used in financing activities	(58,742)	(31,852)	(54,710)
Increase (decrease) in cash and cash equivalents	(283,450)	(176,868)	126,477
Cash and cash equivalents, beginning of period	734,231	911,099	784,622
Cash and cash equivalents, end of period	450,781	734,231	911,099
Parent/Issuer [Member]
Cash provided by (used in) operating activities	(445,136)	(324,688)	(632,060)
Investing Activities
Capital expenditures	(1,108)	(2,700)	(3,320)
Additions to prepaid royalties	0	0	0
Proceeds from disposals and divestitures	0	57,625	0
Proceeds from sale-leaseback transactions			0
Purchases of short term investments	(246,735)	(211,929)	(213,726)
Proceeds from sales of short term investments	290,205	205,611	194,537
Proceeds from sale of investments in equity investments and securities	0	9,464
Withdrawals (deposits) of restricted cash	0	0	3,453
Investments in and advances to affiliates, net	(913)	(2,541)	(5,451)
Cash provided by (used in) investing activities	41,449	55,530	(24,507)
Financing Activities
Contributions from parent			0
Proceeds from term loan and senior notes			644,000
Payments to retire debt			(628,660)
Payments on term loan	(19,500)	(19,500)	(17,250)
Net payments on other debt	(2,692)	(1,258)	(6,324)
Debt financing costs		(2,219)	(19,864)
Dividends paid		(2,123)	(25,475)
Other		(15)
Expenses related to debt restructuring	(27,910)
Transactions with affiliates, net	219,250	67,125	838,160
Cash used in financing activities	169,148	42,010	784,587
Increase (decrease) in cash and cash equivalents	(234,539)	(227,148)	128,020
Cash and cash equivalents, beginning of period	572,185	799,333	671,313
Cash and cash equivalents, end of period	337,646	572,185	799,333
Guarantor Subsidiaries [Member]
Cash provided by (used in) operating activities	314,535	305,048	637,193
Investing Activities
Capital expenditures	(117,916)	(144,586)	(293,664)
Additions to prepaid royalties	(5,871)	(7,317)	(14,947)
Proceeds from disposals and divestitures	2,191	4,733	433,453
Proceeds from sale-leaseback transactions			34,919
Purchases of short term investments	0	0	0
Proceeds from sales of short term investments	0	0
Proceeds from sale of investments in equity investments and securities	2,259	0
Withdrawals (deposits) of restricted cash	0	0	0
Investments in and advances to affiliates, net	(10,589)	(14,116)	(10,321)
Cash provided by (used in) investing activities	(129,926)	(161,286)	149,440
Financing Activities
Contributions from parent			512
Proceeds from term loan and senior notes			0
Payments to retire debt			0
Payments on term loan	0	0	0
Net payments on other debt	(8,640)	(4,437)	(512)
Debt financing costs		0	0
Dividends paid		0	0
Other		0
Expenses related to debt restructuring	0
Transactions with affiliates, net	(225,899)	(89,385)	(786,683)
Cash used in financing activities	(234,539)	(93,822)	(786,683)
Increase (decrease) in cash and cash equivalents	(49,930)	49,940	(50)
Cash and cash equivalents, beginning of period	150,358	100,418	100,468
Cash and cash equivalents, end of period	100,428	150,358	100,418
Non-Guarantor Subsidiaries [Member]
Cash provided by (used in) operating activities	86,234	(13,942)	50,609
Investing Activities
Capital expenditures	0	0	0
Additions to prepaid royalties	0	0	0
Proceeds from disposals and divestitures	0	0	0
Proceeds from sale-leaseback transactions			0
Purchases of short term investments		0	0
Proceeds from sales of short term investments	0	0	0
Proceeds from sale of investments in equity investments and securities	0	0
Withdrawals (deposits) of restricted cash	(91,864)	(5,678)	0
Investments in and advances to affiliates, net	0		0
Cash provided by (used in) investing activities	(91,864)	(5,678)	0
Financing Activities
Contributions from parent			0
Proceeds from term loan and senior notes			0
Payments to retire debt			0
Payments on term loan	0	0	0
Net payments on other debt	0	0	0
Debt financing costs		(2,300)	(625)
Expenses related to debt restructuring	0
Transactions with affiliates, net	6,649	22,260	(51,477)
Cash used in financing activities	6,649	19,960	(52,102)
Increase (decrease) in cash and cash equivalents	1,019	340	(1,493)
Cash and cash equivalents, beginning of period	11,688	11,348	12,841
Cash and cash equivalents, end of period	12,707	11,688	11,348
Eliminations [Member]
Cash provided by (used in) operating activities	0	0
Investing Activities
Capital expenditures	0	0	0
Additions to prepaid royalties	0	0	0
Proceeds from disposals and divestitures	0	0	0
Proceeds from sale-leaseback transactions			0
Purchases of short term investments	0	0	0
Proceeds from sales of short term investments	0	0	0
Proceeds from sale of investments in equity investments and securities	0	0
Withdrawals (deposits) of restricted cash	0	0	0
Investments in and advances to affiliates, net	0		512
Cash provided by (used in) investing activities	0	0	512
Financing Activities
Contributions from parent			(512)
Proceeds from term loan and senior notes			0
Payments to retire debt			0
Payments on term loan	0	0	0
Net payments on other debt	0	0	0
Debt financing costs		0	0
Dividends paid		0	0
Other		0
Expenses related to debt restructuring	0
Transactions with affiliates, net	0	0	0
Cash used in financing activities	0	0	(512)
Increase (decrease) in cash and cash equivalents	0	0	0
Cash and cash equivalents, beginning of period	0	0	0
Cash and cash equivalents, end of period	$ 0	$ 0	$ 0

Valuation and Qualifying Acc126

Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other assets — other notes and accounts receivable
Reserves deducted from asset accounts:
Balance at Beginning of Year	$ 159	$ 775	$ 1,043
Additions (Reductions) Charged to Costs and Expenses	7,683	0	346
Charged to Other Accounts	0	0	0
Deductions	0	616	614
Balance at End of Year	7,842	159	775
Current assets — supplies and inventory
Reserves deducted from asset accounts:
Balance at Beginning of Year	6,625	8,446	12,589
Additions (Reductions) Charged to Costs and Expenses	431	580	503
Charged to Other Accounts	0	(76)	(2,274)
Deductions	1,065	2,325	2,372
Balance at End of Year	5,991	6,625	8,446
Deferred income taxes
Reserves deducted from asset accounts:
Balance at Beginning of Year	270,251	43,322	34,663
Additions (Reductions) Charged to Costs and Expenses	860,847	226,929	8,659
Charged to Other Accounts	0	0	0
Deductions	0	0	0
Balance at End of Year	$ 1,131,098	$ 270,251	$ 43,322