Alpha Natural Resources 10-Q 8 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Document And Entity Information	'	'
Entity Registrant Name	'Alpha Natural Resources, Inc.	'
Entity Central Index Key	'0001301063	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	220,955,822

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues:	'	'	'	'
Coal revenues	$1,028,847	$1,455,702	$3,292,412	$4,660,541
Freight and handling revenues	135,931	154,450	448,316	597,157
Other revenues	26,316	23,657	119,080	158,833
Total revenues	1,191,094	1,633,809	3,859,808	5,416,531
Costs and expenses:	'	'	'	'
Cost of coal sales (exclusive of items shown separately below)	988,995	1,259,174	3,082,330	4,080,964
Freight and handling costs	135,931	154,450	448,316	597,157
Other expenses	120,698	13,357	155,479	43,194
Depreciation, depletion and amortization	196,292	238,894	650,021	797,516
Amortization of acquired intangibles, net	2,748	-11,682	908	-64,480
Selling, general and administrative expenses (exclusive of depreciation, depletion and amortization shown separately above)	38,899	49,604	120,664	160,626
Asset impairment and restructuring	2,017	13,676	24,358	1,028,610
Goodwill impairment	253,102	0	253,102	1,525,332
Total costs and expenses	1,738,682	1,717,473	4,735,178	8,168,919
Income (loss) from operations	-547,588	-83,664	-875,370	-2,752,388
Other income (expense):	'	'	'	'
Interest expense	-62,233	-47,345	-182,587	-139,313
Interest income	1,008	1,328	3,133	3,749
Loss on early extinguishment of debt	158	0	-33,039	0
Miscellaneous expense, net	7,277	353	24,131	1,619
Total other expense, net	-53,790	-45,664	-188,362	-133,945
Income (loss) before income taxes	-601,378	-129,328	-1,063,732	-2,886,333
Income tax (expense) benefit	143,137	83,182	309,022	576,765
Net income (loss)	($458,241)	($46,146)	($754,710)	($2,309,568)
Basic loss per common share	($2.07)	($0.21)	($3.42)	($10.49)
Diluted loss per common share	($2.07)	($0.21)	($3.42)	($10.49)
Weighted average shares - basic	220,960,449	220,417,448	220,850,020	220,167,198
Weighted average shares - diluted	220,960,449	220,417,448	220,850,020	220,167,198

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net loss	($458,241)	($46,146)	($754,710)	($2,309,568)
Other comprehensive income (loss), net of tax:	'	'	'	'
Adjustments to and amortization of employee benefit costs, net of income tax of $(40,203) and $46,349, and $(30,028) and $52,490 for the three and nine months ended September 30, 2012 and 2011, respectively	100,753	52,136	109,931	35,127
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent	-946	12,824	-3,998	5,486
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	300	59	-41	-5
Total other comprehensive loss, net of tax	100,107	65,019	105,892	40,608
Total comprehensive loss	($358,134)	$18,873	($648,818)	($2,268,960)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]	'	'	'	'
Amortization of employee benefit costs, income tax	($76,795)	($40,203)	($81,081)	($30,028)
Change in fair value of cash flow hedges, income tax	787	-7,672	2,575	-3,292
Change in fair value of marketable securities income tax	($173)	($35)	$27	$3

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$668,102	$730,723
Trade accounts receivable, net	299,950	418,166
Inventories, net	333,111	398,060
Prepaid expenses and other current assets	826,320	786,273
Total current assets	2,127,483	2,333,222
Property, equipment and mine development costs (net of accumulated depreciation and amortization of $1,752,754 and $1,355,937, respectively)	1,897,685	2,219,016
Owned and leased mineral rights and land (net of accumulated depletion of $839,833 and $522,207 respectively)	7,194,116	7,428,192
Goodwill, net	308,651	567,665
Other acquired intangibles (net of accumulated amortization of $630,518 and $551,584, respectively)	177,345	228,552
Other non-current assets	391,725	313,159
Total assets	12,097,005	13,089,806
Current liabilities:	'	'
Current portion of long-term debt	29,016	95,015
Trade accounts payable	224,893	255,191
Accrued expenses and other current liabilities	1,002,415	872,402
Total current liabilities	1,256,324	1,222,608
Long-term debt	3,344,736	3,291,037
Pension and postretirement medical benefit obligations	1,005,163	1,195,187
Asset retirement obligations	813,443	763,482
Deferred income taxes	790,529	971,001
Other non-current liabilities	514,120	678,676
Total liabilities	7,724,315	8,121,991
Commitments and Contingencies	'	'
Stockholders' Equity	'	'
Preferred stock - par value $0.01	0	0
Common stock - par value $0.01	2,328	2,322
Additional paid-in capital	8,130,733	8,075,694
Accumulated other comprehensive income (loss)	-60,706	-166,598
Treasury stock, at cost	-271,654	-270,302
Accumulated deficit	-3,428,011	-2,673,301
Total stockholders' equity	4,372,690	4,967,815
Total liabilities and stockholders' equity	$12,097,005	$13,089,806

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data in Millions, unless otherwise specified
Property, equipment and mine development costs, accumulated depreciation and amortization	$2,242,382	$1,910,058
Owned and leased mineral rights, accumulated depletion (in dollars)	1,100,281	908,416
Other acquired intangibles, accumulated amortization (in dollars)	$404,597	$655,047
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	400	400
Common stock, shares issued	232.8	232.2
Common stock, shares outstanding	220.9	220.6
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	10	10
Preferred stock, shares issued	0	0
Treasury stock, at cost	11.9	11.6

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating activities:	'	'
Net loss	($754,710)	($2,309,568)
Adjustments to reconcile net loss to net cash provided by operating activities:	'	'
Depreciation, depletion, accretion and amortization	733,282	878,924
Amortization of acquired intangibles, net	908	-64,480
Mark-to-market adjustments for derivatives	1,312	-12,820
Share-based Compensation	18,360	3,945
Goodwill impairment	253,102	1,525,332
Asset impairment and restructuring	24,358	1,028,610
Employee benefit plans, net	43,352	56,033
Loss on early extinguishment of debt	33,039	0
Deferred income taxes	-306,488	-577,744
Other, net	-16,020	-16,271
Changes in operating assets and liabilities:	'	'
Trade accounts receivable, net	118,216	186,737
Inventories, net	61,116	34,826
Prepaid expenses and other current assets	30,728	170,642
Other non-current assets	7,052	-729
Trade accounts payable	-28,332	-195,607
Accrued expenses and other current liabilities	152,816	-342,838
Pension and postretirement medical benefit obligations	-36,647	-35,667
Asset retirement obligations	-31,519	-37,611
Other non-current liabilities	-125,346	13,933
Net cash provided by operating activities	178,579	305,647
Investing activities:	'	'
Capital expenditures	-163,129	-332,592
Acquisition of mineral rights under federal lease	0	-53,501
Purchase of equity-method investments	0	-10,100
Purchases of marketable securities	-738,800	-419,275
Sales of marketable securities	680,452	307,137
Other, net	7,075	7,420
Net cash used in investing activities	-214,402	-500,911
Financing activities:	'	'
Principal repayments of long-term debt	-951,894	-30,000
Principal repayments of capital lease obligations	-12,604	-3,862
Proceeds from borrowings on long-term debt	964,369	0
Debt issuance costs	-24,317	-6,737
Common stock repurchases	-1,352	-6,985
Other	-1,000	-830
Net cash (used in) provided by financing activities	-26,798	-48,414
Net increase (decrease) in cash and cash equivalents	-62,621	-243,678
Cash and cash equivalents at beginning of period	730,723	585,882
Cash and cash equivalents at end of period	$668,102	$342,204

Business_and_Basis_of_Presenta

Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Business and Basis of Presentation	'
	Business and Basis of Presentation
	Business
	Alpha Natural Resources, Inc. and its consolidated subsidiaries (the “Company” and “Alpha”) are primarily engaged in the business of extracting, processing and marketing steam and metallurgical coal from surface and deep mines, and mainly sell to electric utilities, steel and coke producers, and industrial customers. The Company, through its subsidiaries, is also involved in marketing coal produced by others to supplement its own production and, through blending, provides its customers with coal qualities differing from those available from its own production.
	Basis of Presentation
	The accompanying interim condensed consolidated financial statements of the Company are unaudited and prepared in accordance with the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for Form 10-Q. Such rules and regulations allow the omission of certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America as long as the financial statements are not misleading. In the opinion of management, these interim condensed consolidated financial statements reflect all normal and recurring adjustments necessary for a fair presentation of the results for the periods presented. Results of operations for the three and nine months ended September 30, 2013 are not necessarily indicative of the results to be expected for the year ending December 31, 2013 or any other period. These interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements of the Company included in its Annual Report on Form 10-K for the year ended December 31, 2012, filed March 1, 2013.
	The Company’s condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America. The preparation of the Company’s condensed consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant items subject to such estimates and assumptions include inventories; mineral reserves; allowance for non-recoupable advanced mining royalties; asset impairments; reclamation obligations; pensions, postemployment, postretirement medical and other employee benefit obligations; useful lives for depreciation, reserves for workers’ compensation and black lung claims; current and deferred income taxes; reserves for contingencies and litigation and fair value of financial instruments. Estimates are based on facts and circumstances believed to be reasonable at the time; however, actual results could differ from those estimates.
	New Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2013-11, Presentation of Unrecognized Tax Benefits (“ASU 2013-11”). The standard requires an entity to present an unrecognized tax benefit as a reduction of a deferred tax asset for a net operating loss (NOL) carryforward, or similar tax loss or tax credit carryforward, rather than as a liability when the uncertain tax position would reduce the NOL or other carryforward under the tax law of the applicable jurisdiction and the entity intends to use the deferred tax asset for that purpose. ASU 2013-11 is effective for public entities with fiscal periods beginning after December 15, 2013. The Company is already in compliance with this standard.

Asset_Impairment_and_Restructu

Asset Impairment and Restructuring	9 Months Ended
	Sep. 30, 2013
Asset Impairment and Restructuring [Abstract]	'
Asset Impairment and Restructuring	'
	Asset Impairment and Restructuring
	In connection with plans announced to curtail mining operations and the associated company actions, the Company recorded severance expenses of $(266) and $12,781 and professional fees and other expenses of $393 and $9,687 for the three and nine months ended September 30, 2013, respectively. Additionally, during the three months ended September 30, 2013, the Company tested certain of its long-lived asset groups for impairment due primarily to a longer than expected recovery in the metallurgical coal markets and lower production and shipment levels compared with previous estimates and recorded asset impairment charges totaling $1,890 related to mineral reserves in an asset group in its All Other segment.
	During the second quarter of 2012, the Company recorded asset impairment charges totaling $990,923, of which $985,346 was recorded for asset groups in its Eastern Coal Operations segment and $5,577 was recorded for an asset group in the Company’s All Other segment. The asset impairment charges reduced the carrying values of mineral reserves by $714,580, property, plant and equipment by $271,827, and other acquired intangibles by $4,516. Additionally, the Company also recorded severance expenses of $7,495 and $22,931, professional fees and other expenses of $5,462 and $7,493, and reserved $719 and $7,263 for advanced royalties and deposits which may not be recoverable for the three and nine months ended September 30, 2012, respectively.

Goodwill_net_Goodwill_net_Note

Goodwill, net Goodwill, net (Notes)	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Intangible Assets Disclosure [Text Block]	'
	Goodwill, Net
	In connection with the testing of certain of its long-lived assets for impairment (see Note 2), the Company also performed interim goodwill impairment tests during the three months ended September 30, 2013 and during the nine months ended September 30, 2012 and recorded goodwill impairment charges of $253,102 and $1,525,332, respectively, to reduce the carrying value of goodwill to its implied fair value for one reporting unit in its Eastern Coal Operations segment during the three months ended September 30, 2013 and for nine reporting units in its Eastern Coal Operations segment and one reporting unit in its Western Coal Operations segment for the nine months ended September 30, 2012, respectively. Additionally, during the nine months ended September 30, 2013, the Company disposed of $5,912 of goodwill in connection with the contribution of certain assets included in its All Other segment to a joint venture.
	The valuation methodology utilized to estimate the fair value of the Company’s reporting units was based on both a market and income approach and is within the range of fair values yielded under each approach. The income approach was based on a discounted cash flow methodology in which expected future net cash flows were discounted to present value, using an appropriate after-tax weighted average cost of capital. The market approach was based on a guideline company and similar transaction approach. Under the guideline company approach, certain operating metrics from a selected group of publicly traded guideline companies that have similar operations to the Company’s reporting units were used to estimate the fair value of the reporting units. Under the similar transaction approach, recent merger and acquisition transactions for companies that have similar operations to the Company’s reporting units were used to estimate the fair value of the Company’s reporting units.
		Balance as of December 31, 2012			Acquisitions		Impairments/Disposals			Balance as of September 30, 2013
	Goodwill:
	Eastern operations	$	3,024,308		$	—	$	—		$	3,024,308
	Western operations	53,308			—		—			53,308
	All other	5,912			—		—			5,912
	Total goodwill	$	3,083,528		$	—	$	—		$	3,083,528
	Accumulated impairment losses:
	Eastern operations	$	(2,462,555	)	$	—	$	(253,102	)	$	(2,715,657	)
	Western operations	(53,308		)	—		—			(53,308		)
	All other	—			—		(5,912		)	(5,912		)
	Total accumulated impairment losses	$	(2,515,863	)	$	—	$	(259,014	)	$	(2,774,877	)
	Goodwill, net:
	Eastern operations	$	561,753		$	—	$	(253,102	)	$	308,651
	Western operations	—			—		—			—
	All other	5,912			—		(5,912		)	—
	Total goodwill, net	$	567,665		$	—	$	(259,014	)	$	308,651
		Balance as of December 31, 2011			Acquisitions		Impairments			Balance as of December 31, 2012
	Goodwill:
	Eastern operations	$	3,024,308		$	—	$	—		$	3,024,308
	Western operations	53,308			—		—			53,308
	All other	5,912			—		—			5,912
	Total goodwill	$	3,083,528		$	—	$	—		$	3,083,528
	Accumulated impairment losses:
	Eastern operations	$	(802,337	)	$	—	$	(1,660,218	)	$	(2,462,555	)
	Western operations	—			—		(53,308		)	(53,308		)
	All other	—			—		—			—
	Total accumulated impairment losses	$	(802,337	)	$	—	$	(1,713,526	)	$	(2,515,863	)
	Goodwill, net:
	Eastern operations	$	2,221,971		$	—	$	(1,660,218	)	$	561,753
	Western operations	53,308			—		(53,308		)	—
	All other	5,912			—		—			5,912
	Total goodwill, net	$	2,281,191		$	—	$	(1,713,526	)	$	567,665

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income [Abstract]	'
Accumulated Other Comprehensive Income (Loss)	'
	Accumulated Other Comprehensive Income (Loss)
	The following table summarizes the changes to accumulated other comprehensive income (loss) during the nine months ended September 30, 2013:
		Balance as of December 31, 2012			Other comprehensive			Amounts reclassified			Balance
					income (loss) before reclassifications			from accumulated other comprehensive income (loss)			30-Sep-13
	Employee benefit costs	$	(171,394	)	$	108,985		$	946		$	(61,463	)
	Cash flow hedges	4,755			(972		)	(3,026		)	757
	Available-for-sale marketable securities	41			(103		)	62			—
		$	(166,598	)	$	107,910		$	(2,018	)	$	(60,706	)
	The following table summarizes the amounts reclassified from accumulated other comprehensive income (loss) and the statement of operations line items affected by the reclassification during the three and nine months ended September 30, 2013:
	Details about accumulated other comprehensive income (loss) components	Amounts reclassified from accumulated other comprehensive income (loss)						Affected line item in the Condensed Consolidated Statements of Operations
		Three Months Ended September 30, 2013			Nine Months Ended September 30, 2013
	Employee benefit costs:
	Amortization of actuarial loss	$	777		$	4,363		(1)
	Amortization of prior service credit	(955		)	(2,864		)	(1)
	Other	—			58			(1)
	Total before income tax	(178		)	1,557
	Tax benefit (expense)	73			(611		)	Income tax benefit
	Total, net of tax	$	(105	)	$	946
	Cash flow hedges:
	Commodity swaps-coal	$	(1,514	)	$	(3,304	)	Coal revenues
	Commodity swaps-diesel fuel	(220		)	82			Cost of coal sales
	Commodity swaps-natural gas	—			(1,866		)	Other revenues
	Commodity options-natural gas	—			113			Other revenues
	Total before income tax	(1,734		)	(4,975		)
	Tax benefit	788			1,949			Income tax benefit
	Total, net of tax	$	(946	)	$	(3,026	)
	Available-for-sale marketable securities:
	Unrealized gains and losses	$	123		$	103		Interest income
	Tax expense	(45		)	(41		)	Income tax benefit
	Total, net of tax	$	78		$	62
	(1) These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit costs for pension, other postretirement benefit plans and black lung. See Note 14.

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	Earnings Per Share
	The number of shares used to calculate basic earnings per common share is based on the weighted average number of the Company’s outstanding common shares during the respective periods. The number of shares used to calculate diluted earnings per common share is based on the number of common shares used to calculate basic earnings per share plus the dilutive effect of stock options and other stock-based instruments held by the Company’s employees and directors during each period, the Company’s outstanding 3.75% convertible senior notes due 2017 (the “3.75% Convertible Notes”), 2.375% convertible senior notes due 2015 (the “2.375% Convertible Notes”), and 3.25% convertible senior notes due 2015 issued by Alpha Appalachia Holdings, Inc. (the “3.25% Convertible Notes”). As of September 30, 2013 and September 30, 2012, the 2.375% Convertible Notes and the 3.25% Convertible Notes were not convertible. As of September 30, 2013, the 3.75% Convertible Notes were not convertible. The 3.75% Convertible Notes, 2.375% Convertible Notes and 3.25% Convertible Notes become dilutive for earnings per common share calculations under certain circumstances and in specified periods. The shares that would be issued to settle the conversion spread are included in the diluted earnings per share calculation when the conversion option is in the money. In periods of net loss, the number of shares used to calculate diluted earnings per share is the same as basic earnings per share.

Inventories_net

Inventories, net	9 Months Ended
	Sep. 30, 2013
Inventory Disclosure [Abstract]	'
Inventories, net	'
	Inventories, net
	Inventories, net consisted of the following:
		September 30,		December 31,
		2013		2012
	Raw coal	$	38,737	$	58,382
	Saleable coal	199,460		233,550
	Materials, supplies and other, net	94,914		106,128
	Total inventories, net	$	333,111	$	398,060

Marketable_Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'
Marketable Securities	'
	Marketable Securities
	Short-term marketable securities, included in prepaid expenses and other current assets, consisted of the following:
		September 30, 2013
				Unrealized
		Cost		Gain		Loss			Fair value
	Short-term marketable securities:
	U.S. treasury and agency securities(a)	$	97,085	$	14	$	(2	)	$	97,097
	Corporate debt securities(a)	253,639		29		(44		)	253,624
	Total short-term marketable securities	$	350,724	$	43	$	(46	)	$	350,721
		December 31, 2012
				Unrealized
		Cost		Gain		Loss			Fair value
	Short-term marketable securities:
	U.S. treasury and agency securities(a)	$	85,537	$	32	$	(1	)	$	85,568
	Corporate debt securities(a)	211,852		75		(43		)	211,884
	Total short-term marketable securities	$	297,389	$	107	$	(44	)	$	297,452
	(a)	Unrealized gains and losses are recorded as a component of stockholders’ equity.
	Long-term marketable securities, with maturity dates between one and two years, included in other non-current assets, consisted of the following:
		September 30, 2013
				Unrealized
		Cost		Gain		Loss			Fair value
	Long-term marketable securities:
	Corporate debt securities(a)	$	2,250	$	—	$	—		$	2,250
	Mutual funds held in Rabbi Trust(b)	7,277		3,111		(1,558		)	8,830
	Total long-term marketable securities	$	9,527	$	3,111	$	(1,558	)	$	11,080
		December 31, 2012
				Unrealized
		Cost		Gain		Loss			Fair value
	Long-term marketable securities:
	Corporate debt securities(a)	$	754	$	1	$	—		$	755
	Mutual funds held in rabbi trust(b)	7,544		2,084		(1,495		)	8,133
	Total long-term marketable securities	$	8,298	$	2,085	$	(1,495	)	$	8,888
	(a)	Unrealized gains and losses are recorded as a component of stockholders’ equity.
	(b)	Unrealized gains and losses are recorded in current period earnings.

Property_Equipment_and_Mine_De

Property, Equipment and Mine Development Costs	9 Months Ended
	Sep. 30, 2013
Property, Plant and Equipment [Abstract]	'
Property, Equipment and Mine Development Costs	'
	Property, Equipment and Mine Development Costs
	Property, equipment and mine development costs consisted of the following:
		September 30, 2013		December 31, 2012
	Plant and mining equipment	$	3,720,138	$	3,688,516
	Mine development	294,813		304,765
	Office equipment, software and other	65,288		89,510
	Construction in progress	59,828		46,283
	Total property, equipment and mine development costs	4,140,067		4,129,074
	Less accumulated depreciation and amortization	2,242,382		1,910,058
	Total property, equipment and mine development costs, net	$	1,897,685	$	2,219,016

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Long-Term Debt	'
	Long-Term Debt
	Long-term debt consisted of the following:
		September 30,			December 31, 2012
		2013
	6.25% senior notes due 2021	$	700,000		$	700,000
	6.00% senior notes due 2019	800,000			800,000
	9.75% senior notes due 2018	500,000			500,000
	Term loan due 2020	621,875			—
	Term loan due 2016	—			540,000
	3.75% convertible senior notes due 2017	345,000			—
	3.25% convertible senior notes due 2015	305,275			536,162
	2.375% convertible senior notes due 2015	102,697			287,500
	Other	81,234			86,203
	Debt discount	(82,329		)	(63,813		)
	Total long-term debt	3,373,752			3,386,052
	Less current portion	(29,016		)	(95,015		)
	Long-term debt, net of current portion	$	3,344,736		$	3,291,037
	Fourth Amended and Restated Credit Agreement
	On May 22, 2013, the Company entered into a Fourth Amended and Restated Credit Agreement (the “Fourth Amended and Restated Credit Agreement”) with the lenders party thereto, the issuing banks party thereto, Citicorp North America, Inc., as administrative agent and as collateral agent, and all other parties thereto from time to time, which amended and restated the Company’s Third Amended and Restated Credit Agreement, dated as of May 19, 2011, as amended June 26, 2012 (the “Existing Credit Agreement”).
	The Fourth Amended and Restated Credit Agreement includes a new $625,000 senior secured term loan B facility (the “Term Loan Facility”), which matures on May 22, 2020, amortizes in quarterly installments at a rate of 1.0% per year and bears an interest rate at the Company’s option of either LIBOR plus a margin of 2.75% (subject to a LIBOR floor of 0.75%) or an Alternate Base Rate (ABR) plus a margin of 1.75% (subject to an ABR floor of 1.75%). The proceeds of the Term Loan Facility were used to repay the entire $525,000 aggregate principal amount of the Company’s outstanding obligations under its existing term loan A facility under the Existing Credit Agreement, which would have matured on June 30, 2016, with the balance used to pay fees and expenses and for general corporate purposes. The Company recorded a loss on early extinguishment of debt of $9,044, primarily related to fees incurred in the transactions that were not capitalizable and the write off of certain outstanding deferred fees.
	The principal changes to the Existing Credit Agreement effected by the Fourth Amended and Restated Credit Agreement include increasing the existing senior secured revolving facility from $1,000,000 to $1,100,000 through its maturity date of June 30, 2016 and modifying the financial covenants by:
	•	modifying the interest coverage ratio covenant from 2.25 to 1.50 through 2013, from 2.50 to 1.50 during 2014 and from 2.50 to 2.00 from 2015 through the maturity date of the revolving credit facility. Subsequently, on October 2, 2013, the Company entered into an amendment to the Fourth Amended and Restated Credit Agreement (the “Credit Agreement”) which eliminated the interest coverage ratio through the end of 2014 and reduced the interest coverage ratio from 2.00 to 1.25 during 2015 and from 2.00 to 1.50 during the first two quarters of 2016;
	•eliminating the leverage ratio covenant;
	•	extending the applicability of the senior secured leverage ratio of 2.50 through the maturity date of the revolving credit facility; and
	•reducing the minimum liquidity covenant, which applies until December 31, 2014, from $500,000 to $300,000;
	Additionally, the terms of the Credit Agreement (i) further restrict the ability of the Company and its subsidiaries to make investments, loans and acquisitions, incur additional indebtedness, and pay dividends on its capital stock or redeem, repurchase or retire its capital stock; and (ii) require the Company to provide additional collateral to secure the obligations under the Credit Agreement, consisting of receivables previously securing the Second Amended and Restated Receivables Purchase Agreement.
	Termination of Account Receivable Securitization Facility
	Simultaneously with its entry into the Fourth Amended and Restated Credit Agreement, the Company also terminated the Second Amended and Restated Receivables Purchase Agreement, dated as of October 19, 2011 (as amended from time to time, the “A/R Facility”), by and among ANR Receivables Funding, LLC, as seller, Alpha Natural Resources, LLC, as servicer, PNC Bank, National Association, as administrator and LC Bank (as defined therein), and the other parties thereto from time to time. The A/R Facility provided for the issuance of letters of credit in a maximum aggregate amount of $275,000. All previously outstanding letters of credit under the A/R Facility were transferred to the Credit Agreement and were deemed to be issued thereunder. The Company recorded a loss on early extinguishment of debt of $1,358 in connection with the termination, primarily related to the write off of outstanding deferred fees.
	3.75% Convertible Senior Notes due 2017
	On May 13, 2013, the Company issued $345,000 principal amount of 3.75% Convertible Notes. The 3.75% Convertible Notes bear interest at a rate of 3.75% per annum, payable semi-annually in arrears on June 15 and December 15 of each year, and will mature on December 15, 2017.
	The proceeds from the 3.75% Convertible Notes, together with cash on hand, were used to repurchase $225,787 of the Company’s outstanding 3.25% Convertible Notes and $181,403 of the Company’s outstanding 2.375% Convertible Notes. The Company recorded a loss on early extinguishment of debt of $22,795, primarily related to the write off of outstanding debt discounts.
	The Company separately accounts for the liability and equity components of the 3.75% Convertible Notes in a manner reflective of its’ nonconvertible debt borrowing rate. The related deferred loan costs and discount are being amortized and accreted, respectively, over the four-year term of the 3.75% Convertible Notes, and provide for an effective interest rate of 8.49%. As of September 30, 2013, the carrying amount of the debt component was $287,337, and the unamortized debt discount was $57,663. As of September 30, 2013, the carrying amount of the equity component was $61,949.
	The 3.75% Convertible Notes are the Company’s senior unsecured obligations and rank equally with all of its existing and future senior unsecured indebtedness. The 3.75% Convertible Notes are guaranteed on a senior unsecured basis by each of our current and future wholly owned domestic subsidiaries that guarantee the Company’s obligations under its 9.75% senior notes due 2018. The 3.75% Convertible Notes are effectively subordinated to all of the Company’s existing and future secured indebtedness and all existing and future liabilities of its non-guarantor subsidiaries, including trade payables.
	The 3.75% Convertible Notes are convertible in certain circumstances and in specified periods at an initial conversion rate of 99.0589 shares of common stock per $1 of principal amount of notes, subject to adjustment upon the occurrence of certain events set forth in the fourth supplemental indenture (the “Fourth Supplemental Indenture”) to the indenture dated June 1, 2011 (the “Base Indenture” and, together with the Fourth Supplemental Indenture, the “3.75% Convertible Notes Indenture”) governing the 3.75% Convertible Notes, equivalent to an initial conversion price of approximately $10.10 per share of common stock. Upon conversion, the notes may be settled, at the Company’s election, in cash, shares of our common stock or a combination thereof. The Company intends to settle conversions, if any, using a combination of cash and shares.
	The 3.75% Convertible Notes Indenture contains customary terms and covenants, including that upon certain events of default occurring and continuing, either the trustee, Union Bank of California, or the holders of not less than 25% in aggregate principal amount of the 3.75% Convertible Notes then outstanding may declare the principal of the 3.75% Convertible Notes and any accrued and unpaid interest thereon immediately due and payable. In the case of certain events of bankruptcy, insolvency or reorganization relating to the Company, the principal amount of the 3.75% Convertible Notes together with any accrued and unpaid interest thereon will automatically become due and be immediately payable.
	The 3.75% Convertible Notes were not convertible as of September 30, 2013 and, as a result, have been classified as long-term debt as of that date.
	Repurchases of 2.375% and 3.25% Convertible Senior Notes due 2015
	On August 22, 2013, the Company repurchased approximately $3,400 of its outstanding 2.375% Convertible Notes and approximately $5,100 of its outstanding 3.25% Convertible Notes and recorded a gain on early extinguishment of debt of $158.

Asset_Retirement_Obligations

Asset Retirement Obligations	9 Months Ended
	Sep. 30, 2013
Asset Retirement Obligation Disclosure [Abstract]	'
Asset Retirement Obligations	'
	Asset Retirement Obligations
	The following table summarizes the changes in asset retirement obligations for the nine months ended September 30, 2013:
	Total asset retirement obligations at December 31, 2012	$	856,701
	Accretion for the period	45,304
	Revisions in estimated cash flows	(269		)
	Expenditures for the period	(31,519		)
	Total asset retirement obligations at September 30, 2013	$	870,217
	Less current portion	(56,774		)
	Long-term portion	$	813,443

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments and Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments and Fair Value Measurements	'
	Fair Value of Financial Instruments and Fair Value Measurements
	The estimated fair values of financial instruments are determined based on relevant market information. These estimates involve uncertainty and cannot be determined with precision.
	The carrying amounts for cash and cash equivalents, trade accounts receivable, net, prepaid expenses and other current assets, trade accounts payable, and accrued expenses and other current liabilities approximate fair value due to the short maturity of these instruments.
	The following tables set forth by level, within the fair value hierarchy, the Company’s long-term debt at fair value as of September 30, 2013 and December 31, 2012, respectively.
		September 30, 2013
		Carrying			Total Fair		Quoted Prices			Significant		Significant
		Amount			Value		in Active			Other		Unobservable
							Markets			Observable		Inputs
							(Level 1)			Inputs		(Level 3)
										(Level 2)
	6.25% senior notes due 2021	$	700,000		$	570,500	$	570,500		$	—	$	—
	6.00% senior notes due 2019	800,000			666,000		666,000			—		—
	9.75% senior notes due 2018(4)	496,214			511,875		511,875			—		—
	Term loan due 2020(5)	618,911			608,480		—			608,480		—
	3.75% convertible senior notes due 2017(6)	287,337			337,376		337,376			—		—
	3.25% convertible senior notes due 2015(2)	296,942			285,432		285,432			—		—
	2.375% convertible senior notes due 2015(3)	93,114			95,303		95,303			—		—
	Total long-term debt	$	3,292,518		$	3,074,966	$	2,466,486		$	608,480	$	—
		December 31, 2012
		Carrying			Total Fair		Quoted Prices			Significant		Significant
		Amount			Value		in Active			Other		Unobservable
							Markets			Observable		Inputs
							(Level 1)			Inputs		(Level 3)
										(Level 2)
	6.25% senior notes due 2021	$	700,000		$	649,110	$	649,110		$	—	$	—
	6.00% senior notes due 2019	800,000			755,600		755,600			—		—
	9.75% senior notes due 2018(4)	495,161			540,125		540,125			—		—
	Term loan due 2016(1)	539,481			537,316		—			537,316		—
	3.25% convertible senior notes due 2015(2)	515,901			513,375		513,375			—		—
	2.375% convertible senior notes due 2015(3)	249,306			268,094		268,094			—		—
	Total long-term debt	$	3,299,849		$	3,263,620	$	2,726,304		$	537,316	$	—
	(1)	Net of debt discount of $519 as of December 31, 2012.
	(2)	Net of debt discount of $8,332 and $20,261 as of September 30, 2013 and December 31, 2012, respectively.
	(3)	Net of debt discount of $9,584 and $38,194 as of September 30, 2013 and December 31, 2012, respectively.
	(4)	Net of debt discount of $3,786 and $4,839 as of September 30, 2013 and December 31, 2012, respectively.
	(5)	Net of debt discount of $2,964 as of September 30, 2013.
	(6)	Net of debt discount of $57,663 as of September 30, 2013.
	The following tables set forth by level, within the fair value hierarchy, the Company’s financial and non-financial assets and liabilities that were accounted for at fair value on a recurring and non-recurring basis as of September 30, 2013 and December 31, 2012, respectively. Financial and non-financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the determination of fair value for assets and liabilities and their placement within the fair value hierarchy levels.
		September 30, 2013
		Total Fair			Quoted Prices		Significant			Significant
		Value			in Active		Other			Unobservable
					Markets		Observable			Inputs
					(Level 1)		Inputs			(Level 3)
							(Level 2)
	Financial assets (liabilities):
	U.S. treasury and agency securities	$	97,097		$	97,097	$	—		$	—
	Mutual funds held in Rabbi Trust	$	8,830		$	8,830	$	—		$	—
	Corporate debt securities	$	255,874		$	—	$	255,874		$	—
	Forward coal sales	$	9,004		$	—	$	9,004		$	—
	Commodity swaps	$	6,118		$	—	$	6,118		$	—
		December 31, 2012
		Total Fair			Quoted Prices		Significant			Significant
		Value			in Active		Other			Unobservable
					Markets		Observable			Inputs
					(Level 1)		Inputs			(Level 3)
							(Level 2)
	Financial assets (liabilities):
	U.S. treasury and agency securities	$	85,568		$	85,568	$	—		$	—
	Mutual funds held in Rabbi Trust	$	8,133		$	8,133	$	—		$	—
	Corporate debt securities	$	212,639		$	—	$	212,639		$	—
	Forward coal sales	$	15,359		$	—	$	15,359		$	—
	Forward coal purchases	$	(4	)	$	—	$	(4	)	$	—
	Commodity swaps	$	7,080		$	—	$	7,080		$	—
Commodity options	$	138		$	—	$	138		$	—
The following methods and assumptions were used to estimate the fair values of the assets and liabilities in the tables above.
Level 1 Fair Value Measurements
U.S. Treasury and Agency Securities and Mutual Funds Held in Rabbi Trust - The fair value is based on observable market data.
6.25% senior notes due 2021, 6.00% senior notes due 2019, 9.75% senior notes due 2018 (collectively, the “Senior Notes”), 3.75% Convertible Notes, 2.375% Convertible Notes, and 3.25% Convertible Notes - The fair value is based on observable market data.
Level 2 Fair Value Measurements
Corporate Debt Securities - The fair values of the Company’s corporate debt securities are obtained from a third-party pricing service provider. The fair values provided by the pricing service provider are estimated using pricing models, where the inputs to those models are based on observable market inputs including credit spreads and broker-dealer quotes, among other inputs. The Company classifies the prices obtained from the pricing services within Level 2 of the fair value hierarchy because the underlying inputs are directly observable from active markets. However, the pricing models used entail a certain amount of subjectivity and therefore differing judgments in how the underlying inputs are modeled could result in different estimates of fair value.
Forward Coal Purchases and Sales - The fair values of the forward coal purchase and sale contracts were estimated using discounted cash flow calculations based upon actual contract prices and forward commodity price curves. The curves were obtained from independent pricing services reflecting broker market quotes. The fair values are adjusted for counter-party credit risk, when applicable.
Commodity Swaps - The fair values of commodity swaps are estimated using valuation models which include assumptions about commodity prices based on those observed in the underlying markets. The fair values are adjusted for counter-party credit risk, when applicable.
Commodity Options - The fair values of the commodity options were estimated using an option pricing model that incorporates data on the historical volatility of the underlying commodity, the strike price and notional amount of the option, the current market price of the option and a risk free interest rate. The fair values are adjusted for counter-party credit risk, when applicable.
Term Loans due 2016 and 2020 - The fair values of the term loans due 2016 and 2020 were estimated based on market rates of interest offered for debt of similar maturities.

Derivative_Financial_Instrumen

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Financial Instruments	'
	12)    Derivative Financial Instruments
	Forward Contracts
	The Company manages price risk for coal sales and purchases through the use of coal supply agreements. The Company evaluates each of its coal sales and coal purchase forward contracts to determine whether they meet the definition of a derivative and if so, whether they qualify for the normal purchase normal sale (“NPNS”) exception. For those contracts that do meet the definition of a derivative, certain contracts also qualify for the NPNS exception based on management’s intent and ability to physically deliver or take physical delivery of the coal. Contracts that meet the definition of a derivative and do not qualify for the NPNS exception are accounted for at fair value and, accordingly, the Company includes the unrealized gains and losses in current period earnings or losses.
	Swap Agreements
	Commodity Swaps
	The Company uses diesel fuel in its production process and incurs significant expenses for its purchase. Diesel fuel expenses represented approximately 6% of cost of coal sales for the nine months ended September 30, 2013. The Company is subject to the risk of price volatility for this commodity and as a part of its risk management strategy, the Company enters into swap agreements with financial institutions to mitigate the risk of price volatility for diesel fuel. The terms of the swap agreements allow the Company to pay a fixed price and receive a floating price, which provides a fixed price per unit for the volume of purchases being hedged. As of September 30, 2013, the Company had swap agreements outstanding to hedge the variable cash flows related to 66% and 55% of anticipated diesel fuel usage for the remaining three months of 2013 and calendar year 2014, respectively. The average fixed price for these diesel fuel hedge swaps is $3.03 per gallon and $2.82 per gallon for the remaining three months of 2013 and calendar year 2014, respectively. All cash flows associated with derivative instruments are classified as operating cash flows in the Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2013 and 2012.
	The following tables present the fair values and location of the Company’s derivative instruments within the Condensed Consolidated Balance Sheets:
				Asset Derivatives
	Derivatives designated as	Statement of Financial Position Location		September 30,			December 31,
	cash flow hedging instruments			2013			2012
	Commodity swaps	Prepaid expenses and other current assets		$	—		$	6,484
	Commodity swaps	Other non-current assets		—			4,718
	Commodity options	Prepaid expenses and other current assets		—			138
				$	—		$	11,340
	Derivatives not designated as	Statement of Financial Position Location		September 30,			December 31,
	cash flow hedging instruments			2013			2012
	Commodity swaps	Prepaid expenses and other current assets		$	6,718		$	—
	Commodity swaps	Other non-current assets		1,714			—
	Forward coal sales	Prepaid expenses and other current assets		8,876			15,359
	Forward coal sales	Other non-current assets		128			—
				$	17,436		$	15,359
	Total asset derivatives			$	17,436		$	26,699
				Liability Derivatives
	Derivatives designated as	Statement of Financial Position Location		September 30,			December 31,
	cash flow hedging instruments			2013			2012
	Commodity swaps	Accrued expenses and other current liabilities		$	—		$	2,457
	Commodity swaps	Other non-current liabilities		—			972
				$	—		$	3,429
	Derivatives not designated as	Statement of Financial Position Location		September 30,			December 31,
	cash flow hedging instruments			2013			2012
	Commodity swaps	Other non-current liabilities		$	770		$	—
	Forward coal purchases	Accrued expenses and other current liabilities		—			4
	Commodity swaps	Accrued expenses and other current liabilities		1,544			693
				$	2,314		$	697
	Total liability derivatives			$	2,314		$	4,126
	The following tables present the gains and losses from derivative instruments for the nine months ended September 30, 2013 and 2012 and their location within the Condensed Consolidated Financial Statements:
	Derivatives designated as		Gain (loss) reclassified						Gain (loss) recorded
	cash flow hedging instruments		from accumulated other						in accumulated other
			comprehensive income (loss) to earnings						comprehensive income (loss)
			2013			2012			2013			2012
	Commodity swaps(1) (2) (3)		$	3,094		$	9,190		$	(909	)	$	14,715
	Commodity options(1) (2)		(68		)	—			(63		)	(39		)
			$	3,026		$	9,190		$	(972	)	$	14,676
	(1)	Amounts are recorded as a component of cost of coal sales in the Condensed Consolidated Statements of Operations.
	(2)	Net of tax.
	(3)	Ineffectiveness during the period was immaterial.
	Derivatives not designated as		Gain (loss) recorded in earnings
	cash flow hedging instruments		Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2013			2012			2013			2012
	Forward coal sales(1)		$	(5,149	)	$	(48,131	)	$	(6,354	)	$	5,424
	Forward coal purchases(1)		(4		)	16,723			4			7,391
	Commodity swaps(2)		5,340			625			5,038			377
	Interest rate swap(3)		—			(42		)	—			(372		)
			$	187		$	(30,825	)	$	(1,312	)	$	12,820
	(1)	Amounts are recorded as a component of other revenues in the Condensed Consolidated Statements of Operations.
	(2)	Amounts are recorded as a component of other expenses in the Condensed Consolidated Statements of Operations.
	(3)	Amounts are recorded as a component of interest expense in the Condensed Consolidated Statements of Operations.
	Unrealized losses recorded in accumulated other comprehensive income (loss) are generally reclassified to income or loss as the financial swaps settle and the Company purchases the underlying items that are being hedged. During the next twelve months, the Company expects to reclassify approximately $3,081, net of tax, to earnings.
	During the three months ended September 30, 2013, the Company elected to cease applying hedge accounting to outstanding commodity swaps. Changes in fair value of those derivative instruments are now recorded in earnings. Amounts previously recognized in accumulated other comprehensive income (loss) will be recognized in income when the underlying transactions are consummated.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	A reconciliation of the statutory federal income tax benefit at 35% to the actual income tax benefit is as follows:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Federal statutory income tax benefit	$	(210,482	)	$	(45,265	)	$	(372,306	)	$	(1,010,217	)
	Increases (reductions) in taxes due to:
	Percentage depletion allowance	(7,062		)	(28,255		)	(27,909		)	(61,157		)
	State taxes, net of federal tax impact	(9,151		)	(10,760		)	(19,190		)	(32,490		)
	State statutory tax rate change, net of federal tax impact	(2,524		)	—			(2,524		)	(6,397		)
	Non-deductible fines and penalties	1,253			1,085			12,472			2,909
	Non-deductible goodwill impairment	88,585			—			88,585			506,634
	Change in valuation allowance	(5,070		)	(2,048		)	2,614			20,706
	Other, net	1,314			2,061			9,236			3,247
	Income tax benefit	$	(143,137	)	$	(83,182	)	$	(309,022	)	$	(576,765	)

Employee_Benefit_Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2013
Compensation and Retirement Disclosure [Abstract]	'
Employee Benefit Plans	'
	Employee Benefit Plans
	The Company sponsors or participates in several benefit plans for its employees, including postretirement health care and life insurance, defined benefit and defined contribution pension plans, and provides black lung benefits.
	Components of Net Periodic Pension Costs
	The components of net periodic benefit costs (credits) are as follows:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Interest cost	$	8,220		$	7,952		$	22,673		$	24,148
	Expected return on plan assets	(10,001		)	(9,815		)	(28,145		)	(28,978		)
	Amortization of net actuarial loss	205			551			712			1,286
	Loss on settlement	—			—			58			—
	Net periodic benefit credits	$	(1,576	)	$	(1,312	)	$	(4,702	)	$	(3,544	)
	Components of Net Periodic Costs of Other Postretirement Benefit Plans
	The components of net periodic benefit costs are as follows:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Service cost	$	3,329		$	4,381		$	10,612		$	12,465
	Interest cost	10,183			10,748			29,799			32,923
	Amortization of prior service cost (credit)	(955		)	104			(2,864		)	313
	Amortization of net actuarial loss	410			1,749			2,871			3,653
	Net periodic benefit cost	$	12,967		$	16,982		$	40,418		$	49,354
	Components of Net Periodic Costs of Black Lung
	The components of net periodic benefit costs are as follows:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Service cost	$	657		$	2,080		$	2,076		$	6,034
	Interest cost	1,691			1,384			4,825			4,228
	Expected return on plan assets	(30		)	(12		)	(46		)	(39		)
	Amortization of net actuarial loss	162			—			780			—
	Net periodic benefit cost	$	2,480		$	3,452		$	7,635		$	10,223
	In connection with testing our goodwill for impairment during the three months ended September 30, 2013, the Company remeasured its obligations under its pension plans, other postretirement benefit plans and its black lung obligations. The discount rates for each plan were updated. The weighted average discount rate for all the plans was 4.59%. As a result, the Company decreased its liabilities for its pension plans, other postretirement benefit plans and black lung obligations by $60,267, $107,542 and $9,915, respectively, with an offset recorded in accumulated other comprehensive income (loss).

StockBased_Compensation_Awards

Stock-Based Compensation Awards	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation Awards	'
	Stock-Based Compensation Awards
	On May 22, 2013, the Board of Directors authorized an additional 3,600,000 shares of common stock for issuance under the 2012 LTIP Plan. The 2012 LTIP Plan is currently authorized for the issuance of awards of up to 10,000,000 shares of common stock, and as of September 30, 2013, 4,265,659 shares of common stock were available for grant under the plan.
	During the nine months ended September 30, 2013, the Company awarded certain of its executives and key employees 1,599,386 time-based restricted share units and 1,531,787 performance-based restricted share units under its existing stock plans. The time-based share units vest, subject to continued employment, ratably over three years or cliff vest after three years (with accelerated vesting upon a change of control and certain retirement scenarios). The performance-based share units cliff vest after three years, subject to continued employment and the satisfaction of the performance criteria (with accelerated vesting upon a change of control and certain retirement scenarios). The performance-based restricted share units awarded under the existing stock plans during the nine months ended September 30, 2013 have the potential to be distributed from 0% to 200% of the awarded amount, depending on the actual results versus the pre-established performance criteria over the three-year period.
	At September 30, 2013, the Company had two types of stock-based awards outstanding: restricted share units (both time-based and performance-based) and stock options. Stock-based compensation expense totaled $5,762 and $6,409 for the three months ended September 30, 2013 and 2012, respectively. Stock-based compensation expense totaled $18,360 and $3,945, for the nine months ended September 30, 2013 and 2012, respectively. For the three months ended September 30, 2013 and 2012, approximately 73% and 76%, respectively, of stock-based compensation expense is reported as selling, general and administrative expenses. For the nine months ended September 30, 2013 and 2012, approximately 77% and 15%, respectively, of stock-based compensation expense is reported as selling, general and administrative expenses. Approximately 27% and 24%, of stock-based compensation expense was recorded as cost of coal sales for the three months ended September 30, 2013 and 2012, respectively. Approximately 23% and 85%, of stock-based compensation expense was recorded as cost of coal sales for the nine months ended September 30, 2013 and 2012, respectively.
	The Company is authorized to repurchase common shares from employees (upon the election by the employee) to satisfy the employees’ minimum statutory tax withholdings upon the vesting of restricted stock and restricted share units (both time-based and performance-based).  Shares that are repurchased to satisfy the employees’ minimum statutory tax withholdings are recorded in treasury stock at cost, and these shares are not added back into the pool of shares available for grant of the respective plans. During the nine months ended September 30, 2013 and 2012, the Company repurchased 165,709 and 381,969, respectively, of common shares from employees at an average price paid per share of $8.16 and $18.29, respectively.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	(a) General
	Estimated losses from loss contingencies are accrued by a charge to income when information available indicates that it is probable that an asset has been impaired or a liability has been incurred and the amount of the loss can be reasonably estimated. If a loss contingency is not probable or reasonably estimable, disclosure of the loss contingency is made in the consolidated financial statements when it is at least reasonably possible that a loss may be incurred and that the loss could be material.
	(b) Commitments and Contingencies
	Commitments
	The Company leases coal mining and other equipment under long-term capital and operating leases with varying terms. In addition, the Company leases mineral interests and surface rights from land owners under various terms and royalty rates.
	The Company has obligations for a federal coal lease, which contains an estimated 222,000 tons of proven and probable coal reserves in the Powder River Basin. The annual installments in the period from 2013 through 2015 of $42,130 are due each November until the obligation is satisfied.
	Contingencies
	Extensive regulation of the impacts of mining on the environment and of maintaining workplace safety, and related litigation, has had or may have a significant effect on the Company’s costs of production and results of operations. Further regulations, legislation or litigation in these areas may also cause the Company’s sales or profitability to decline by increasing costs or by hindering the Company’s ability to continue mining at existing operations or to permit new operations.
	During the normal course of business, contract-related matters arise between the Company and its customers. When a loss related to such matters is considered probable and can reasonably be estimated, the Company records a liability. During the nine months ended September 30, 2013, the Company recorded a gain of $55,454 in other expenses in the condensed consolidated statement of operations related to the resolution of a contract-related matter.
	(c) Guarantees and Financial Instruments with Off-Balance Sheet Risk
	In the normal course of business, the Company is a party to certain guarantees and financial instruments with off-balance sheet risk, such as bank letters of credit, performance or surety bonds, and other guarantees and indemnities related to the obligations of affiliated entities which are not reflected in the Company’s Condensed Consolidated Balance Sheets. Management does not expect any material losses to result from these guarantees or other off-balance sheet financial instruments.
	Letters of Credit
	As of September 30, 2013, the Company had $150,621 of letters of credit outstanding under its senior secured revolving facility.
	(d) Legal Proceedings
	The Company’s legal proceedings range from cases brought by a single plaintiff to purported class actions. These legal proceedings, as well as governmental examinations, involve various business units and a variety of claims including, but not limited to, contract disputes, personal injury claims, property damage claims (including those resulting from blasting, trucking and flooding), environmental and safety issues, and employment matters. While some matters pending against the Company or its subsidiaries specify the damages claimed by the plaintiffs, many seek an unquantified amount of damages or are at very early stages of the legal process. Even when the amount of damages claimed against the Company or its subsidiaries is stated, (i) the claimed amount may be exaggerated or unsupported; (ii) the claim may be based on a novel legal theory or involve a large number of parties; (iii) there may be uncertainty as to the likelihood of a class being certified or the ultimate size of the class; (iv) there may be uncertainty as to the outcome of pending appeals or motions; and/or (v) there may be significant factual issues to be resolved. As a result, the Company may be unable to estimate a range of possible loss for matters that have not yet progressed sufficiently through discovery and development of important factual information and legal issues. Other matters have progressed sufficiently that the Company is able to estimate a range of possible loss. Accordingly, for those legal proceedings and governmental examinations disclosed below as to which a loss is reasonably possible in future periods and for which the Company is able to estimate a range of possible loss, the current estimated range is up to $350,000 in excess of the accrued liability (if any) related to those matters. This aggregate range represents the Company’s estimate of additional possible loss in excess of the accrued liability (if any) with respect to these matters and net of third party indemnification arrangements (if any, other than insurance) as described below related to those matters, based on currently available information, including any damages claimed by the plaintiffs, and is subject to significant judgment and a variety of assumptions and inherent uncertainties. For example, at the time of making an estimate, the Company may have only preliminary, incomplete, or inaccurate information about the facts underlying a claim; its assumptions about the future rulings of the court or other tribunal on significant issues, or the behavior and incentives of adverse parties, regulators, indemnitors or co-defendants, may prove to be wrong; and the outcomes it is attempting to predict are often not amenable to the use of statistical or other quantitative analytical tools. In addition, from time to time an outcome may occur that the Company had not accounted for in its estimate because it had considered that outcome to be remote. Furthermore, as noted above, the aggregate range does not include any matters for which the Company is not able to estimate a range of possible loss. Accordingly, the estimated aggregate range of possible loss does not represent the Company’s maximum loss exposure. The legal proceedings and governmental examinations underlying the estimated range will change from time to time, and actual results may vary significantly from the current estimate. The Company intends to defend these legal proceedings vigorously, litigating or settling cases where in the Company’s judgment it would be in the best interest of shareholders to do so.
	For purposes of FASB ASC Topic 450 (“ASC 450”), an event is “reasonably possible” if “the chance of the future event or events occurring is more than remote but less than likely” and an event is “remote” if “the chance of the future event or events occurring is slight.” ASC 450 requires accrual for a liability when it is (a) “probable that one or more future events will occur confirming the fact of loss” and (b) “the amount of loss can be reasonably estimated.” If a range of loss is estimated, the best estimate within the range is required to be accrued. If no amount within the range is a better estimate, the minimum amount of the range is required to be accrued.
	The Company evaluates, on a quarterly basis, developments in legal proceedings and governmental examinations that could cause an increase or decrease in the amount of the reserves previously recorded. Excluding fees paid to external legal counsel, the Company recognized expense, net of expected insurance recoveries, associated with litigation-related reserves of $116,552 and $7,893 during the three months ended September 30, 2013 and 2012, respectively.
	Federal Securities Class Actions
	Upper Big Branch (“UBB”) Purported Securities Class Action
	On April 29, 2010 and May 28, 2010, two purported class actions that were subsequently consolidated into one case were brought against, among others, Massey Energy Company (“Massey”), now the Company’s subsidiary Alpha Appalachia Holdings, Inc. (“Alpha Appalachia”), in the United States District Court for the Southern District of West Virginia in connection with alleged violations of the federal securities laws.  The lead plaintiffs allege, purportedly on behalf of a class of former Massey stockholders, that (i) Massey and certain former Massey directors and officers violated Section 10(b) of the Securities and Exchange Act of 1934, as amended, (the “Exchange Act”), and Rule 10b-5 thereunder by intentionally misleading the market about the safety of Massey’s operations and that (ii) Massey’s former officers violated Section 20(a) of the Exchange Act by virtue of their control over persons alleged to have committed violations of Section 10(b) of the Exchange Act.  The lead plaintiffs seek a determination that this action is a proper class action; certification as class representatives; an award of compensatory damages in an amount to be proven at trial, including interest thereon; and an award of reasonable costs and expenses, including counsel fees and expert fees.
	On February 16, 2011, the lead plaintiffs moved to partially lift the statutory discovery stay imposed under the Private Securities Litigation Reform Act of 1995.  On March 3, 2011, the United States moved to intervene and to stay discovery until the completion of criminal proceedings allegedly arising from the same facts that allegedly give rise to this action. On July 9, 2012, the court entered an order maintaining the stay of discovery until the earlier of either the completion of the United States’ criminal investigation of the UBB explosion or January 15, 2013. The court has extended the stay several times; most recently, on July 18, 2013, the court further extended the existing discovery stay until January 15, 2014.
	On April 25, 2011, the defendants moved to dismiss the operative complaint.  On March 27, 2012, the court denied the defendants’ motion to dismiss. On July 16, 2012, the Company filed its answer to the consolidated amended class action complaint.
	In early October 2013, the parties participated in mediation.  The parties have made significant progress toward reaching a tentative understanding to settle the case for $265,000. Additional material terms must still be negotiated.  If a definitive settlement is achieved and approved by the court, the settlement would result in the dismissal of the action.
	The Company expects insurance recoveries of approximately $70,000 to help cover the cost of the settlement. In connection with these developments, Alpha recorded an increase in its loss contingency accruals of approximately $115,000 during the three months ended September 30, 2013.  The Company plans to continue settlement discussions in an effort to resolve all outstanding issues, including the form of consideration.  Whether the Company can resolve those issues, and when, remains uncertain.
	Emerald Purported Securities Class Action
	On July 13, 2012, a purported class action brought on behalf of a putative class of former Massey stockholders was filed in Boone County, West Virginia Circuit Court. The complaint asserts claims under the Securities Act of 1933, as amended, against the Company and certain of its officers and current and former directors, and generally asserts that the defendants made false statements about the Company’s Emerald mine in its public filings associated with the acquisition of Massey by the Company (the “Massey Acquisition”). The plaintiff seeks, among other relief, an award of compensatory damages in an amount to be proven at trial.
	On August 16, 2012, the defendants removed the case to the United States District Court for the Southern District of West Virginia. On August 30, 2012, the plaintiff filed a motion to remand the case back to the Circuit Court of Boone County, West Virginia. On September 13, 2012, the defendants filed an opposition to the plaintiff’s motion to remand.
	The defendants filed a motion to dismiss the action on October 19, 2012, and the plaintiff filed an opposition to that motion on November 2, 2012. On November 5, 2012, the federal court remanded the case back to the Boone County Circuit Court (without ruling on the pending motion to dismiss). The plaintiff filed an amended complaint in the Boone County Circuit Court on February 6, 2013. The defendants filed motions to dismiss the amended complaint on March 22, 2013 and March 29, 2013, which motions are currently pending. The Boone County Circuit Court has set a preliminary trial date of June 24, 2014.
	UBB Explosion and Related Investigations and Litigation
	On April 5, 2010, before the Massey Acquisition by the Company, an explosion occurred at the UBB mine, resulting in the deaths of 29 miners.  The Federal Mine Safety and Health Administration (“MSHA”), the Office of Miner’s Health, Safety, and Training of the State of West Virginia (“State”), and the Governor’s Independent Investigation Panel (“GIIP”) initiated investigations into the cause of the UBB explosion and related issues.  Additionally, the United States Attorney for the Southern District of West Virginia (the “Office”) commenced a grand jury investigation.  The GIIP published its final report on May 19, 2011; MSHA released its final report on December 6, 2011; and the State released its final report on February 23, 2012.
	On December 6, 2011, the Company, the Office and the United States Department of Justice entered into a Non-Prosecution Agreement (the “Agreement”) resolving the criminal investigation against Massey and its affiliates relating to the UBB explosion and other health and safety related issues at Massey, and the Company also reached a comprehensive settlement with MSHA resolving outstanding civil citations, violations, and orders related to MSHA’s investigation arising from the UBB explosion and other non-UBB related matters involving legacy Massey entities prior to the Massey Acquisition. The Agreement does not resolve individual responsibilities related to the UBB explosion.
	Under the terms of the Agreement and MSHA settlement, the Company has agreed to pay outstanding MSHA fines, and has agreed to invest in additional measures designed to improve miner health and safety, provide restitution to the families of the fallen miners and two individuals injured in the UBB explosion, and create a charitable organization to research mine safety. The Company has further agreed to cooperate fully with all governmental agencies in all continuing investigations and prosecutions against any individuals that arise out of the UBB explosion and related conduct described in the Agreement until such investigations and prosecutions are concluded.
	The Company cannot predict the outcome of these investigations, including whether or not any individual will become subject to possible criminal and civil penalties or enforcement actions.  In order to accommodate these investigations, the UBB mine was initially idled. On April 20, 2012, the Company was authorized by regulatory authorities to close the UBB mine permanently, and on June 19, 2012, the sealing of the mine was completed.
	On June 28, 2012, sixteen individuals who claim to have been injured in the UBB explosion filed a petition in the United States District Court for the Southern District of West Virginia to amend or set aside the Agreement. On July 27, 2012, Alpha and Alpha Appalachia filed a motion to dismiss. The injury claims of those sixteen individuals were separately settled in August 2012, and on August 29, 2012, the court ordered that the action be dismissed and stricken from the docket.
	On October 19, 2012, the administrators for the estates of three miners who died in the UBB explosion filed an action against Alpha and Alpha Appalachia in the United States District Court for the Southern District of West Virginia claiming they are entitled to “criminal restitution” under the Agreement. On November 27, 2012, the defendants filed their motion to dismiss the complaint. The plaintiffs were subsequently granted leave to amend their complaint, which they filed on January 23, 2013, rendering the defendants’ previously filed motion to dismiss moot. On May 10, 2013, the court dismissed the amended complaint. On July 17, 2013, the plaintiffs filed another complaint seeking “criminal restitution” under the Agreement, which defendants moved to dismiss on August 16, 2013. The same plaintiffs filed their appeal of the May dismissal with the United States Court of Appeals for the Fourth Circuit on July 29, 2013. On October 18, 2013, the Court of Appeals dismissed the appeal for lack of jurisdiction. On October 30, 2013, the court granted defendants’ motion to dismiss the complaint filed on July 17, 2013 with prejudice.
	Wrongful Death and Personal Injury Suits
	Twenty of the twenty-nine families of the deceased miners filed wrongful death suits against Massey and certain of its subsidiaries in Boone County Circuit Court and Wyoming County Circuit Court. In addition, as of July 19, 2013, two seriously injured employees had filed personal injury claims against Massey and certain of its subsidiaries in Boone County Circuit Court seeking damages for physical injuries and/or alleged psychiatric injuries, and thirty-nine employees had filed lawsuits against Massey and certain of its subsidiaries in Boone County Circuit Court and Wyoming County Circuit Court alleging emotional distress or personal injuries due to their proximity to the explosion.  On April 19, 2012, the Company filed a motion to transfer the Wyoming County lawsuits to Boone County.
	On October 19, 2011, the Boone County Circuit Court ordered that the cases pending before it be mediated by a panel of three mediators. These mediations are, per order of the court, strictly confidential. The Company reached agreements to settle with all twenty-nine families of the deceased miners as well as the two employees who were seriously injured. The settlements reached with the families of the deceased miners have received court approval. The settlements relating to the two serious injuries did not require court approval.
	On May 4, 2012, the Boone County Circuit Court ordered that the remaining personal injury and emotional distress claims continue to be mediated through July 6, 2012. Until that date, a stay was in place for all remaining cases until further order from the court. The stay was lifted on July 6, 2012 but mediation was ordered to continue. On July 20, 2012, the stay was reinstated for discovery-related activities at the request of the United States Attorney and by agreement of the parties. On August 19, 2013, at the request of the United States Attorney, the stay was extended until the earlier of either the completion of the United States’ criminal investigation of the UBB explosion or January 15, 2014. Mediation efforts in August 2012 successfully resolved all but two of the personal injury and emotional distress claims. On June 26, 2013, the court granted the Company’s motion to dismiss in part, dismissing plaintiffs’ claims alleging the tort of outrage and negligent infliction of emotional distress. Two of plaintiffs’ claims remain pending. The Wyoming County lawsuits were settled and dismissed prior to the court ruling on the Company’s motion to transfer.
	On April 5, 2012, one of the families of the deceased miners filed a class action suit in Boone County Circuit Court, purportedly on behalf of the families that settled their claims prior to the mediation, alleging fraudulent inducement into a contract, naming as defendants Massey, the Company and certain of its subsidiaries, the Company’s CEO and the Company’s Board of Directors.
	On June 17, 2013 and August 29, 2013 two complaints were filed in Boone County Circuit Court alleging personal injury claims relating to the UBB explosion. The Company moved to dismiss both complaints on July 17, 2013 and October 16, 2013 respectively.
	Uniform Fraudulent Transfers Act Action
	On June 1, 2011, certain of the plaintiffs who filed wrongful death cases filed a complaint against Massey, Massey Coal Services, Inc., Performance Coal Company, and certain individuals in the Circuit Court of Boone County, West Virginia, alleging that the Massey Acquisition represented a fraudulent transfer intended to prevent plaintiffs from recovering damages in their wrongful death actions. Plaintiffs request that the court order defendants to post a bond of at least $500,000. Each plaintiff in this action has agreed to settle their wrongful death cases, as discussed above, and as part of those settlements, has also agreed to dismiss this action. On May 14, 2012, the court entered an order dismissing this case with prejudice.
	Derivative and Related Class Action Litigation
	UBB-Related Derivatives Actions
	A number of purported former Massey stockholders brought lawsuits derivatively, purportedly on behalf of Massey, in West Virginia and Delaware state courts, in connection with the April 5, 2010 explosion at the UBB mine and in connection with claims allegedly arising out of the Massey Acquisition. Certain of these former stockholders also initiated contempt proceedings in West Virginia state court in connection with alleged violations of the settlement of a previous derivative lawsuit. In addition, these and other purported former Massey stockholders have asserted class action claims allegedly arising out of the Massey Acquisition in Delaware and West Virginia state courts and Virginia federal court. These cases are summarized below.
	Delaware Chancery Court Suit
	In a case filed on April 23, 2010 in Delaware Chancery Court, In re Massey Energy Company Derivative and Class Action Litigation (“In re Massey”), a number of purported former Massey stockholders (the “Delaware Plaintiffs”) allege, purportedly on behalf of Massey, that certain former Massey directors and officers breached their fiduciary duties by failing to monitor and oversee Massey’s employees, allegedly resulting in fines against Massey and the explosion at UBB, and by wasting corporate assets by paying allegedly excessive and inflated amounts to former Massey Chairman and Chief Executive Officer Don L. Blankenship as part of his retirement package.  The Delaware Plaintiffs also allege, on behalf of a purported class of former Massey stockholders, that certain former Massey directors breached their fiduciary duties by agreeing to the Massey Acquisition.  The Delaware Plaintiffs allege that defendants breached their fiduciary duties by failing to secure the best price possible, by failing to secure any downside protection for the acquisition consideration, and by purportedly eliminating the possibility of a superior proposal by agreeing to a “no shop” provision and a termination fee.  In addition, the Delaware Plaintiffs allege that defendants agreed to the Massey Acquisition to eliminate the liability that defendants faced on the Delaware Plaintiffs’ derivative claims.  Finally, the Delaware Plaintiffs allege that defendants failed to fully disclose all material information necessary for Massey stockholders to cast an informed vote on the Massey Acquisition.
	The Delaware Plaintiffs also name the Company and Mountain Merger Sub, Inc. (“Merger Sub”), the Company’s wholly-owned subsidiary created for purposes of effecting the Massey Acquisition, which, at the effective time of the Massey Acquisition, was merged with and into Massey, as defendants. The Delaware Plaintiffs allege that the Company and Merger Sub aided and abetted the former Massey directors’ alleged breaches of fiduciary duty and agreed to orchestrate the Massey Acquisition for the purpose of eliminating the former Massey directors’ potential liability on the derivative claims. Two additional putative class actions were brought against Massey, certain former Massey directors and officers, the Company and Merger Sub in the Delaware Court of Chancery following the announcement of the Massey Acquisition, which were consolidated for all purposes with In re Massey on February 9, 2011 and February 24, 2011, respectively.
	The Delaware Plaintiffs seek an award against each defendant for restitution and/or compensatory damages, plus pre-judgment interest; an order establishing a litigation trust to preserve the derivative claims asserted in the complaint; and an award of costs, disbursements and reasonable allowances for fees incurred in this action. The Delaware Plaintiffs also sought to enjoin consummation of the Massey Acquisition.  The court denied their motion for a preliminary injunction on May 31, 2011.
	On June 10, 2011, Massey moved to dismiss the Delaware Plaintiffs’ derivative claims on the ground that the Delaware Plaintiffs, as former Massey stockholders, lacked the legal right to pursue those claims, and the Company and Alpha Appalachia Merger Sub moved to dismiss the purported class action claim against them for failure to state a claim upon which relief may be granted.  On June 10 and 13, 2011, certain former Massey director and officer defendants moved to dismiss the derivative claims and filed answers to the remaining direct claims.
	On September 14, 2011, the parties submitted a Stipulation Staying Proceedings, which stayed the matter until March 1, 2012, without prejudice to the parties’ right to seek an extension or a termination of the stay by application to the court.  The court approved the stipulation and entered the stay that same day.  The court has extended the stay several times; most recently, on July 29, 2013, the court further extended the existing discovery stay until the earlier of the completion of the United States’ criminal investigation of the UBB explosion or January 15, 2014.
	West Virginia State Court Derivative Suit
	In a case filed on April 15, 2010 in West Virginia state court, three purported former Massey stockholders (the “West Virginia Plaintiffs”) allege, purportedly on behalf of Massey, that certain former Massey directors and officers breached their fiduciary duties by failing to monitor and oversee Massey’s employees, allegedly resulting in fines against Massey and the explosion at UBB. The West Virginia Plaintiffs seek an award against each defendant and in favor of Massey for the amount of damages sustained by Massey as a result of defendants’ alleged breaches of fiduciary duty and an award to the West Virginia Plaintiffs of the costs and disbursements of the action, including reasonable attorneys’ fees, accountants’ and experts’ fees, costs, and expenses.
	On May 2, 2011, the West Virginia Plaintiffs moved for leave to amend their complaint to add Alpha and Merger Sub as additional defendants and to add claims allegedly arising out of the then-proposed Massey Acquisition. In their proposed amended complaint, the West Virginia Plaintiffs allege that certain former Massey directors breached their fiduciary duties by failing to obtain the highest price reasonably available for Massey and by failing to disclose material information to Massey’s then-stockholders in connection with the stockholder vote on the Massey Acquisition. The West Virginia Plaintiffs also allege that Massey, Merger Sub and the Company aided and abetted the former Massey directors’ breaches of fiduciary duty. The West Virginia Plaintiffs further allege that certain former Massey directors wasted corporate assets by failing to maintain sufficient internal controls over Massey’s safety and environmental reporting; failing to properly consider the interests of Massey and its stockholders, including the value of the derivative claims asserted by the West Virginia Plaintiffs in the Massey Acquisition; failing to conduct proper supervision; paying undeserved incentive compensation to certain Massey executive directors, particularly former Massey Chairman and CEO Don L. Blankenship during Massey’s alleged years of noncompliance with safety regulations and more recently as part of Blankenship’s retirement package; incurring millions of dollars in fines due to safety and environmental violations; and incurring potentially hundreds of millions of dollars of legal liability and/or legal costs to defend defendants’ allegedly unlawful actions. Finally, the West Virginia Plaintiffs’ proposed amended complaint alleges that certain former Massey directors were unjustly enriched by their compensation as directors.
	On May 25, 2011, the West Virginia Plaintiffs filed a petition with the West Virginia Supreme Court for a preliminary injunction against the consummation of the Massey Acquisition, which was denied on May 31, 2011.
	On June 24, 2011, the defendants moved to dismiss the West Virginia Plaintiffs’ original complaint on the grounds that plaintiffs, as former Massey stockholders, lacked the legal right to pursue those claims, or, alternatively, to stay this case in favor of In re Massey, described above.  Defendants also filed an opposition to the West Virginia Plaintiffs’ motion to amend.  On August 19, 2011, the West Virginia Plaintiffs filed a combined memorandum in opposition to defendants’ motion to dismiss or stay and in further support of their motion to amend.  On August 22, 2011, defendants filed a memorandum in further support of their motion to dismiss or stay and in further opposition to plaintiffs’ motion to amend.  On August 23, 2011, the court held a hearing on defendants’ motion to dismiss and plaintiffs’ motion to amend.  Without deciding the motions, the court requested the parties to submit competing proposed orders containing findings of fact and conclusions of law and proposed scheduling orders for the court’s consideration, which the parties did on September 9, 2011.  The motions remain pending.
	West Virginia State Court - Contempt Proceedings
	On April 16, 2010, Manville Personal Injury Settlement Trust (“Manville”), one of the West Virginia Plaintiffs, filed a petition in the Circuit Court of Kanawha County, West Virginia, requesting that the court initiate civil contempt proceedings against certain of the then-current members of Massey’s board of directors with respect to alleged violations of a settlement agreement.  In July 2007, Manville filed a complaint, purportedly on behalf of Massey, alleging that certain of Massey’s then directors and officers breached their fiduciary duties.  On May 20, 2008, the parties executed a stipulation of settlement, which the court subsequently approved.  The settlement provided for a release of all claims that were or could have been asserted on behalf of Massey in exchange for, among other things, certain corporate governance reforms and an agreement that the Massey board of directors would make a Corporate Social Responsibility Report to its stockholders on an annual basis that would include, among other things, a report on Massey’s environmental and worker safety compliance.  Manville alleges that Massey’s 2009 Corporate Social Responsibility Report did not contain a sufficient report on worker safety compliance.  On April 22, 2010, the court issued an order for a rule to show cause, initiating the contempt proceedings.
	On May 31, 2011, Manville, now joined by the other two West Virginia Plaintiffs, filed a new petition for civil contempt, requesting that the court initiate civil contempt proceedings against certain of the then-current members of Massey’s board of directors and certain then-current Massey officers in connection with certain additional alleged violations of the settlement.
	On June 22, 2011, the individual defendants that had been served with the new petition filed a motion to dismiss that petition, as well as the original April 16 petition, and also moved to vacate the 2008 order, in which the court approved the settlement, as against them.  On June 28, 2011, nominal defendant Alpha Appalachia joined in the individual defendants’ motions to dismiss and vacate.  On July 21, 2011, the court held a hearing on the defendants’ motions to dismiss and vacate.
	On September 29, 2011, the court granted the individual defendants’ motions to dismiss and vacate and ordered that the contempt proceedings be terminated in their entirety.  The plaintiffs appealed the dismissal of the contempt proceedings to the Supreme Court of Appeals of West Virginia. On September 12, 2013, the Supreme Court of Appeals of West Virginia affirmed the September 29, 2011 order granting defendants’ motion to dismiss the contempt petitions.
Mine Water Discharge Suits
On March 20, 2012, three environmental groups filed a citizen’s suit against two of the Company’s subsidiaries, Alex Energy, Inc. and Elk Run Coal Company, Inc., in federal court in the Southern District of West Virginia alleging violations of the terms of the subsidiaries’ water discharge permits. The plaintiffs seek a civil penalty as well as injunctive relief.
On April 16, 2012, three environmental groups filed a citizen’s suit in federal court in the Southern District of West Virginia against one of the Company’s subsidiaries, Boone East Development Company (“Boone East”), which owns land previously mined and reclaimed by other companies, alleging that Boone East is discharging pollutants without a permit. Plaintiffs have since voluntarily terminated this action.
On May 9, 2012, three environmental groups filed a citizen’s suit in federal court in the Southern District of West Virginia against two of the Company’s subsidiaries alleging violations of the terms of the subsidiaries’ water discharge permits. The plaintiffs seek a civil penalty as well as injunctive relief.
On May 15, 2012, the West Virginia Department of Environmental Protection filed a civil enforcement action against the Company’s subsidiary Riverside Energy Company, LLC, in McDowell County Circuit Court in West Virginia seeking civil penalties and injunctive relief based on alleged discharge of selenium in excess of permitted levels.
On July 16, 2012, three environmental groups filed a citizen’s suit in federal court in the Southern District of West Virginia against seven of the Company’s subsidiaries alleging violations of the terms of the subsidiaries’ water discharge permits. The plaintiffs seek a civil penalty as well as injunctive relief.
On December 31, 2012 and January 2, 2013, two separate environmental groups filed citizen’s suits in federal court in the Western District of Pennsylvania against Emerald Coal Resources, L.P., and other of the Company’s subsidiaries, alleging violations of the terms of the subsidiaries’ water discharge permits. The first of these cases has since been voluntarily dismissed by the plaintiffs. The plaintiffs in the remaining case seek a civil penalty as well as injunctive relief.
On March 27, 2013, the Company’s subsidiary Alex Energy, Inc. (“Alex”) was served with a complaint from the Sierra Club, and others, alleging improper discharges by Alex into Spruce Run and Road Fork of Robinson Creek in Nicholas County, West Virginia. Alex has appropriate permits for discharges into those tributaries, and the discharges discussed in the plaintiffs’ complaint are undertaken by Alex in compliance with its permits.
On April 10, 2013, the Company’s subsidiary Bandmill Coal Co. (“Bandmill”) was served with a complaint from the Sierra Club, and others, alleging discharges of selenium from the site of Bandmill’s former Tower Mountain surface mine into waters of the United States without a proper permit. The Tower Mountain site is closed, the property has been reclaimed and West Virginia regulators previously determined that Bandmill no longer needs a National Pollutant Discharge Elimination System (“NPDES”) permit for the Tower Mountain site at issue. Bandmill was also released from its obligations to monitor and treat water discharging from the site. Bandmill believes it has operated in compliance with all laws and regulations regarding discharges from the Tower Mountain site.
On July 23, 2013, the Company’s subsidiary, Alex Energy, Inc., was served with a complaint alleging that discharges from the PGM No. 1 surface mine into Hardway Branch of Twentymile Creek violated state water quality standards for selenium.
On July 29, 2013, the Company’s subsidiary, Pigeon Creek Processing Co. (“Pigeon Creek”), was notified by environmental groups that they intend to sue Pigeon Creek for discharging selenium from the Stonega impoundment area without the proper authorization in the NPDES permit.
On October 3, 2013, Bandmill was notified by environmental groups that they intend to sue Bandmill for alleged discharges from the Right Hand Fork Surface Mine in connection with state water quality standards for selenium.
The Company is currently in discussions with the EPA about addressing certain of these and other matters.
Nicewonder Litigation
In December 2004, prior to the Company’s acquisition of Nicewonder in October 2005, the Affiliated Construction Trades Foundation (“ACTF”), a division of the West Virginia State Building and Construction Trades Council, brought an action against the West Virginia Department of Transportation, Division of Highways (“WVDOH”) and Nicewonder Contracting, Inc. (“NCI”), which became the Company’s wholly-owned indirect subsidiary as a result of the Nicewonder acquisition, in the United States District Court in the Southern District of West Virginia. The plaintiff sought a declaration that the contract between NCI and the State of West Virginia related to NCI’s road construction project was illegal as a violation of applicable West Virginia and federal competitive bidding and prevailing wage laws and sought to enjoin performance of the contract, but did not seek monetary damages.
On September 30, 2009, the District Court issued an order that dismissed or denied for lack of standing all of the plaintiff’s claims under federal law and remanded the remaining state claims to the Circuit Court of Kanawha County, West Virginia for resolution.  On May 7, 2010, the Circuit Court of Kanawha County entered summary judgment in favor of NCI.  On June 22, 2011, the West Virginia Supreme Court of Appeals reversed the Circuit Court order granting summary judgment in favor of NCI, and remanded the case back to the Circuit Court for further proceedings. Following remand, ACTF filed a motion for summary judgment, which the Circuit Court denied on November 9, 2011.  ACTF challenged the order denying its summary judgment motion to the West Virginia Supreme Court of Appeals.
On June 21, 2012, the West Virginia Supreme Court of Appeals issued an opinion finding that ACTF has standing to pursue its claims and remanded the case back to the Circuit Court of Kanawha County, West Virginia for further proceedings. NCI’s portion of the highway project under the contract is complete.
The case is now pending in the Circuit Court of Kanawha County, West Virginia. A settlement between NCI and ACTF was agreed upon in early January 2013, prior to the scheduled trial date, January 14, 2013. The Company does not expect to incur any out-of-pocket expenditures in connection with the settlement. The trial proceeded among the remaining parties.
On February 7, 2013, the Company received notice of a purported class action lawsuit against NCI filed in the Circuit Court of Mingo County, West Virginia by a former NCI employee (the “NCI Employee Litigation”). The plaintiff in the NCI Employee Litigation is represented by the same attorney who represents the plaintiff in the ACTF litigation, and the complaint’s allegations raise issues similar to those in the ACTF litigation.
On February 26, 2013, the Circuit Court of Kanawha County ruled that the contract in dispute in the ACTF litigation, as well as the awarding and implementation of the contract were in violation of West Virginia law. The Company is reviewing the Court’s ruling and evaluating its implications in relation to the NCI Employee Litigation.  The Company believes that NCI has meritorious defenses to the claims asserted in the NCI Employee Litigation.
NCI filed its answer to the complaint in the NCI Employee Litigation on March 4, 2013.  On April 23, 2013, the Circuit Court of Kanawha County, West Virginia, granted NCI’s motion to transfer and entered an agreed order transferring the NCI Employee Litigation from the Circuit Court of Mingo County to the Circuit Court of Kanawha County.
Fluor Litigation
Alpha Appalachia and certain of its subsidiaries are also parties to a number of lawsuits and other legal proceedings related to certain non-coal businesses (the “Prior Business”) previously conducted by its former affiliate Fluor Corporation. These lawsuits include the Alexander-Pederson-Helig cases in which two of Alpha Appalachia’s subsidiaries, Appalachia Holding Company (“Appalachia Holding”) and DRIH Corporation (“DRIH”), were named defendants along with Fluor. In July 2011, those cases resulted in a jury award in the City of St. Louis Circuit Court in favor of the plaintiffs for $38,500 in compensatory and economic damages and $320,000 in punitive damages. The total aggregate judgment against Alpha Appalachia’s subsidiaries is $118,500.
Under the terms of the Distribution Agreement entered into by Alpha Appalachia and Fluor as of November 30, 2000 in connection with the spin-off of Fluor by Massey, Fluor agreed to indemnify Massey with respect to all such legal proceedings and assumed defense of the proceedings. Consistent with that agreement, in September 2011, Fluor submitted to the court a number of surety bonds covering the full amount of the judgments against Fluor and Alpha Appalachia’s subsidiaries in the Alexander-Pederson-Helig cases. On January 24, 2012, Fluor moved for a reduction in the surety bond amount pending appeal. The Missouri Court of Appeals granted Fluor’s motion on March 1, 2012 and reduced the amount of the surety bonds required to be submitted by the defendants collectively to $150,000, which Fluor has submitted on behalf of itself and Alpha Appalachia’s subsidiaries. The Company has recorded an indemnity receivable of $118,500 and has accrued a liability of $118,500, included in prepaid expenses and other current assets and accrued expenses and other current liabilities, respectively, in the condensed consolidated balance sheet at September 30, 2013. The appeal of the judgments in the Alexander-Pederson-Helig cases remains pending.
In connection with Fluor’s sale of the Prior Business to a group of purchasers (the “Rennert Entities”) in 1994, the Rennert Entities had agreed to indemnify Fluor and its affiliates for losses and liabilities arising from the Prior Business. In late 2010, the Rennert Entities settled with the plaintiffs in the Alexander-Pederson-Helig cases without indemnifying or obtaining a release for the benefit of Fluor and Alpha Appalachia’s subsidiaries.
In January 2012, the Rennert Entities filed suit against Fluor and two of Alpha Appalachia’s subsidiaries in the United States District Court for the Eastern District of Missouri seeking return of funds previously paid by the Rennert Entities to settle personal injury and property damage claims against Fluor and Alpha Appalachia’s subsidiaries allegedly arising out of the Prior Business and a declaration of non-liability for indemnification with respect to the Alexander-Pederson-Helig cases and any future claims or judgments against Fluor and Alpha Appalachia’s subsidiaries arising out of the Prior Business. Also in January 2012, Fluor filed suit against the Rennert Entities in Missouri state court alleging various breach of contract and tort claims and seeking a declaratory judgment regarding the Rennert Entities’ indemnification obligations to Fluor and Alpha Appalachia’s subsidiaries against claims arising out of the Prior Business. On February 21, 2012, Appalachia Holding and DRIH joined Fluor as plaintiffs in this suit. At the same time, Fluor, Appalachia Holding and DRIH moved to dismiss, or in the alternative, to stay the suit pending in federal court in Missouri in favor of the Missouri state court action. On June 21, 2012, Missouri federal court stayed the case before it in favor of the suit pending in the Missouri state court.
On April 4, 2012, the Rennert entities moved to dismiss the Missouri state court action. On July 13, 2012, the Missouri state court scheduled an expedited hearing on the Rennert entities’ pending motions to dismiss for August 15, 2012. On October 5, 2012, the court denied the Rennert entities’ motions to dismiss each of Fluor’s and Alpha Appalachia’s subsidiaries’ claims except for one claim for contribution, which the court dismissed. All defendants answered on October 25, 2012. Discovery has commenced and is ongoing.
Harman Litigation
In December 1997, Wellmore Coal Corporation (“Wellmore”), then a subsidiary of A. T. Massey Coal Company (“A. T. Massey”), which is now a subsidiary of the Company, declared force majeure under its coal supply agreement with Harman Mining Corporation (“Harman”) and reduced the amount of coal to be purchased from Harman.  In October 1998, Harman and several entities affiliated with it, as well as their ultimate sole shareholder (together “Harman plaintiffs”), sued A.T. Massey and five of its subsidiaries (the “Massey Defendants”) in the Circuit Court of Boone County, West Virginia, alleging that the Massey Defendants tortiously interfered with Wellmore’s agreement with Harman, causing Harman to go out of business.  In August 2002, the jury awarded the plaintiffs $50,000 in compensatory and punitive damages.
In October 2006, the Massey Defendants appealed the case to the Supreme Court of Appeals of West Virginia (“WV Supreme Court”).  In November 2007, the WV Supreme Court issued a 3-2 majority opinion reversing the judgment against the Massey Defendants and remanding the case to the Circuit Court of Boone County with directions to enter an order dismissing the case, with prejudice, in its entirety.  On motion by the Harman plaintiffs, the WV Supreme Court agreed to rehear the case but, in April 2008, it again reversed the judgment against the Massey Defendants and remanded the case with direction to enter an order dismissing the case, with prejudice, in its entirety.
In July 2008, the Harman plaintiffs petitioned the United States Supreme Court (the “U.S. Supreme Court”) to review the WV Supreme Court’s dismissal of their claims. In December 2008, the U.S. Supreme Court agreed to review the case based on the question of whether a justice of the WV Supreme Court should have recused himself from the appeal. The U.S. Supreme Court found that the justice should have recused himself and ruled in June 2009 that the matter should be reheard by the WV Supreme Court.
The WV Supreme Court heard oral arguments on the matter in September 2009, and in November 2009 reversed the lower court’s decision, ruling that all claims brought in connection with the parties dealings must be brought in Virginia.  The Harman plaintiffs subsequently requested that the WV Supreme Court reconsider its decision; the WV Supreme Court denied that request.
In November 2010, Harman plaintiffs re-filed their claims in the Circuit Court of Buchanan County, Virginia, this time solely against A.T. Massey, seeking compensatory damages of approximately $44,000, plus pre- and post-judgment interest and punitive damages. A. T. Massey filed a plea of res judicata, and in December 2011 the Buchanan County Circuit Court granted the plea and dismissed the Harman plaintiffs’ claims. The Harman plaintiffs appealed that decision to the Virginia Supreme Court, and on April 18, 2013, the Virginia Supreme Court reversed the decision of the Buchanan County Circuit Court, finding that res judicata did not bar the Harman plaintiffs’ claims. The matter was remanded to the Buchanan County Circuit Court for further proceedings, and that court has set a trial date in late April 2014.
Other Legal Proceedings
In addition to the matters disclosed above, the Company and its subsidiaries are involved in a number of legal proceedings and governmental examinations incident to its normal business activities.  While the Company cannot predict the outcome of these proceedings, the Company does not believe that any liability arising from these matters individually or in the aggregate should have a material impact upon its consolidated cash flows, results of operations or financial condition.

Segment_Information

Segment Information	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segment Information	'
	Segment Information
	The Company extracts, processes and markets steam and metallurgical coal from surface and deep mines for sale to electric utilities, steel and coke producers, and industrial customers. The Company operates only in the United States with mines in Northern and Central Appalachia and the Powder River Basin. The Company has two reportable segments: Western Coal Operations, which consists of two Powder River Basin surface mines as of September 30, 2013, and Eastern Coal Operations, which consists of 60 underground mines and 24 surface mines in Northern and Central Appalachia as of September 30, 2013, as well as coal brokerage activities.
	In addition to the two reportable segments, the All Other category includes an idled underground mine in Illinois; expenses associated with certain closed mines; Dry Systems Technologies; revenues and royalties from the sale of coalbed methane and natural gas extraction; equipment sales and repair operations; terminal services; the leasing of mineral rights; general corporate overhead and corporate assets and liabilities. The Company evaluates the performance of its segments based on EBITDA, which the Company defines as net income (loss) plus interest expense, income tax expense, amortization of acquired intangibles, net, and depreciation, depletion and amortization, less interest income and income tax benefit.
	Segment operating results and capital expenditures for the three months ended September 30, 2013 were as follows:
		Eastern			Western			All			Consolidated
		Coal			Coal			Other
		Operations			Operations
	Total revenues	$	1,050,495		$	128,151		$	12,448		$	1,191,094
	Depreciation, depletion, and amortization	$	175,767		$	13,686		$	6,839		$	196,292
	Amortization of acquired intangibles, net	$	3,434		$	(690	)	$	4		$	2,748
	EBITDA	$	(244,689	)	$	30,478		$	(126,902	)	$	(341,113	)
	Capital expenditures	$	54,725		$	1,047		$	351		$	56,123
	Segment operating results and capital expenditures for the three months ended September 30, 2012 were as follows:
		Eastern			Western			All			Consolidated
		Coal			Coal			Other
		Operations			Operations
	Total revenues	$	1,446,374		$	171,982		$	15,453		$	1,633,809
	Depreciation, depletion, and amortization	$	215,961		$	16,868		$	6,065		$	238,894
	Amortization of acquired intangibles, net	$	(15,940	)	$	3,480		$	778		$	(11,682	)
	EBITDA	$	123,544		$	42,305		$	(21,948	)	$	143,901
	Capital expenditures	$	80,695		$	4,150		$	2,503		$	87,348
	Acquisition of mineral rights under federal lease	$	—		$	17,393		$	—		$	17,393
	Segment operating results and capital expenditures for the nine months ended September 30, 2013 were as follows:
		Eastern			Western			All			Consolidated
		Coal			Coal			Other
		Operations			Operations
	Total revenues	$	3,451,903		$	369,377		$	38,528		$	3,859,808
	Depreciation, depletion, and amortization	$	586,486		$	40,863		$	22,672		$	650,021
	Amortization of acquired intangibles, net	$	2,561		$	(1,666	)	$	13		$	908
	EBITDA	$	(73,936	)	$	74,276		$	(233,689	)	$	(233,349	)
	Capital expenditures	$	156,934		$	4,149		$	2,046		$	163,129
	Segment operating results and capital expenditures for the nine months ended September 30, 2012 were as follows:
		Eastern			Western			All			Consolidated
		Coal			Coal			Other
		Operations			Operations
	Total revenues	$	4,899,430		$	459,320		$	57,781		$	5,416,531
	Depreciation, depletion, and amortization	$	730,894		$	47,284		$	19,338		$	797,516
	Amortization of acquired intangibles, net	$	(78,067	)	$	10,472		$	3,115		$	(64,480	)
	EBITDA	$	(1,978,561	)	$	25,616		$	(64,788	)	$	(2,017,733	)
	Capital expenditures	$	304,010		$	16,927		$	11,655		$	332,592
	Acquisition of mineral rights under federal lease	$	—		$	53,501		$	—		$	53,501
	The following table presents a reconciliation of EBITDA to net loss:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	EBITDA	$	(341,113	)	$	143,901		$	(233,349	)	$	(2,017,733	)
	Interest expense	(62,233		)	(47,345		)	(182,587		)	(139,313		)
	Interest income	1,008			1,328			3,133			3,749
	Income tax benefit	143,137			83,182			309,022			576,765
	Depreciation, depletion and amortization	(196,292		)	(238,894		)	(650,021		)	(797,516		)
	Amortization of acquired intangibles, net	(2,748		)	11,682			(908		)	64,480
	Net loss	$	(458,241	)	$	(46,146	)	$	(754,710	)	$	(2,309,568	)
	The following table presents total assets and goodwill as of September 30, 2013 and December 31, 2012:
		Total Assets						Goodwill
		September 30,			December 31,			September 30,			December 31,
		2013			2012			2013			2012
	Eastern Coal Operations	$	9,817,222		$	10,691,029		$	308,651		$	561,753
	Western Coal Operations	609,905			647,292			—			—
	All Other	1,669,878			1,751,485			—			5,912
	Total	$	12,097,005		$	13,089,806		$	308,651		$	567,665
	The Company markets produced, processed, and purchased coal to customers in the United States and in international markets. Export revenues totaled $517,872 and $1,716,565, or approximately 43% and 44%, respectively, of total revenues for the three and nine months ended September 30, 2013, respectively. Export revenues totaled $639,977 and $2,296,369, or approximately 39%, and 42%, respectively, of total revenues for the three and nine months ended September 30, 2012, respectively.

Supplemental_Guarantor_and_Non

Supplemental Guarantor and Non-Guarantor Financial Information	9 Months Ended
	Sep. 30, 2013
Supplemental Guarantor and Non-Guarantor Financial Information [Abstract]	'
Supplemental Guarantor and Non-Guarantor Financial Information	'
	(18)    Guarantor and Non-Guarantor Information
	The Company has issued Senior Notes and 3.75% Convertible Notes and may issue new registered debt securities (the “New Notes”) in the future that are and will be, respectively, fully and unconditionally guaranteed, jointly and severally, on a senior or subordinated unsecured basis by certain of the Company’s 100% owned subsidiaries (the “New Notes Guarantor Subsidiaries”). The Company’s Non-Guarantor Subsidiaries are comprised of ANR Receivables Funding, LLC, Alpha Coal India Private Limited, Gray Hawk Insurance Company and Rockridge Coal Company, which were not guarantors of the Senior Notes or the 3.75% Convertible Notes and would not be guarantors of the New Notes.
	As the Company’s parent company has no independent assets or operations, the guarantees are full and unconditional and joint and several, and the subsidiaries of the parent company other than the subsidiary guarantors are minor as of September 30, 2013, separate consolidated financial statements and other disclosures are not presented because management believes that such information would not be material to holders of the Senior Notes, the 3.75% Convertible Notes or any New Notes or related guarantees that may be issued by the Company.

Goodwill_net_Goodwill_net_Tabl

Goodwill, net Goodwill, net (Tables)	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Schedule of Goodwill [Table Text Block]	'
	ions to the Company’s reporting units were used to estimate the fair value of the Company’s reporting units.
		Balance as of December 31, 2012			Acquisitions		Impairments/Disposals			Balance as of September 30, 2013
	Goodwill:
	Eastern operations	$	3,024,308		$	—	$	—		$	3,024,308
	Western operations	53,308			—		—			53,308
	All other	5,912			—		—			5,912
	Total goodwill	$	3,083,528		$	—	$	—		$	3,083,528
	Accumulated impairment losses:
	Eastern operations	$	(2,462,555	)	$	—	$	(253,102	)	$	(2,715,657	)
	Western operations	(53,308		)	—		—			(53,308		)
	All other	—			—		(5,912		)	(5,912		)
	Total accumulated impairment losses	$	(2,515,863	)	$	—	$	(259,014	)	$	(2,774,877	)
	Goodwill, net:
	Eastern operations	$	561,753		$	—	$	(253,102	)	$	308,651
	Western operations	—			—		—			—
	All other	5,912			—		(5,912		)	—
	Total goodwill, net	$	567,665		$	—	$	(259,014	)	$	308,651
		Balance as of December 31, 2011			Acquisitions		Impairments			Balance as of December 31, 2012
	Goodwill:
	Eastern operations	$	3,024,308		$	—	$	—		$	3,024,308
	Western operations	53,308			—		—			53,308
	All other	5,912			—		—			5,912
	Total goodwill	$	3,083,528		$	—	$	—		$	3,083,528
	Accumulated impairment losses:
	Eastern operations	$	(802,337	)	$	—	$	(1,660,218	)	$	(2,462,555	)
	Western operations	—			—		(53,308		)	(53,308		)
	All other	—			—		—			—
	Total accumulated impairment losses	$	(802,337	)	$	—	$	(1,713,526	)	$	(2,515,863	)
	Goodwill, net:
	Eastern operations	$	2,221,971		$	—	$	(1,660,218	)	$	561,753
	Western operations	53,308			—		(53,308		)	—
	All other	5,912			—		—			5,912
	Total goodwill, net	$	2,281,191		$	—	$	(1,713,526	)	$	567,665

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income [Abstract]	'
Schedule of Accumulated Other Comprehensive Income (Loss)	'
	The following table summarizes the changes to accumulated other comprehensive income (loss) during the nine months ended September 30, 2013:
		Balance as of December 31, 2012			Other comprehensive			Amounts reclassified			Balance
					income (loss) before reclassifications			from accumulated other comprehensive income (loss)			30-Sep-13
	Employee benefit costs	$	(171,394	)	$	108,985		$	946		$	(61,463	)
	Cash flow hedges	4,755			(972		)	(3,026		)	757
	Available-for-sale marketable securities	41			(103		)	62			—
		$	(166,598	)	$	107,910		$	(2,018	)	$	(60,706	)
Reclassification out of Accumulated Other Comprehensive Income	'
	The following table summarizes the amounts reclassified from accumulated other comprehensive income (loss) and the statement of operations line items affected by the reclassification during the three and nine months ended September 30, 2013:
	Details about accumulated other comprehensive income (loss) components	Amounts reclassified from accumulated other comprehensive income (loss)						Affected line item in the Condensed Consolidated Statements of Operations
		Three Months Ended September 30, 2013			Nine Months Ended September 30, 2013
	Employee benefit costs:
	Amortization of actuarial loss	$	777		$	4,363		(1)
	Amortization of prior service credit	(955		)	(2,864		)	(1)
	Other	—			58			(1)
	Total before income tax	(178		)	1,557
	Tax benefit (expense)	73			(611		)	Income tax benefit
	Total, net of tax	$	(105	)	$	946
	Cash flow hedges:
	Commodity swaps-coal	$	(1,514	)	$	(3,304	)	Coal revenues
	Commodity swaps-diesel fuel	(220		)	82			Cost of coal sales
	Commodity swaps-natural gas	—			(1,866		)	Other revenues
	Commodity options-natural gas	—			113			Other revenues
	Total before income tax	(1,734		)	(4,975		)
	Tax benefit	788			1,949			Income tax benefit
	Total, net of tax	$	(946	)	$	(3,026	)
	Available-for-sale marketable securities:
	Unrealized gains and losses	$	123		$	103		Interest income
	Tax expense	(45		)	(41		)	Income tax benefit
	Total, net of tax	$	78		$	62
	(1) These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit costs for pension, other postretirement benefit plans and black lung. See Note 14.

Inventories_net_Tables

Inventories, net (Tables)	9 Months Ended
	Sep. 30, 2013
Inventory Disclosure [Abstract]	'
Schedule of inventories, net	'
	Inventories, net consisted of the following:
		September 30,		December 31,
		2013		2012
	Raw coal	$	38,737	$	58,382
	Saleable coal	199,460		233,550
	Materials, supplies and other, net	94,914		106,128
	Total inventories, net	$	333,111	$	398,060

Marketable_Securities_Tables

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2013
Investments, Debt and Equity Securities [Abstract]	'
Schedule of Available-for-sale Securities Long-Term Portion [Table Text Block]	'
	Long-term marketable securities, with maturity dates between one and two years, included in other non-current assets, consisted of the following:
		September 30, 2013
				Unrealized
		Cost		Gain		Loss			Fair value
	Long-term marketable securities:
	Corporate debt securities(a)	$	2,250	$	—	$	—		$	2,250
	Mutual funds held in Rabbi Trust(b)	7,277		3,111		(1,558		)	8,830
	Total long-term marketable securities	$	9,527	$	3,111	$	(1,558	)	$	11,080
		December 31, 2012
				Unrealized
		Cost		Gain		Loss			Fair value
	Long-term marketable securities:
	Corporate debt securities(a)	$	754	$	1	$	—		$	755
	Mutual funds held in rabbi trust(b)	7,544		2,084		(1,495		)	8,133
	Total long-term marketable securities	$	8,298	$	2,085	$	(1,495	)	$	8,888
	(a)	Unrealized gains and losses are recorded as a component of stockholders’ equity.
	(b)	Unrealized gains and losses are recorded in current period earnings.
Schedule of short-term marketable securities	'
	Short-term marketable securities, included in prepaid expenses and other current assets, consisted of the following:
		September 30, 2013
				Unrealized
		Cost		Gain		Loss			Fair value
	Short-term marketable securities:
	U.S. treasury and agency securities(a)	$	97,085	$	14	$	(2	)	$	97,097
	Corporate debt securities(a)	253,639		29		(44		)	253,624
	Total short-term marketable securities	$	350,724	$	43	$	(46	)	$	350,721
		December 31, 2012
				Unrealized
		Cost		Gain		Loss			Fair value
	Short-term marketable securities:
	U.S. treasury and agency securities(a)	$	85,537	$	32	$	(1	)	$	85,568
	Corporate debt securities(a)	211,852		75		(43		)	211,884
	Total short-term marketable securities	$	297,389	$	107	$	(44	)	$	297,452
	(a)	Unrealized gains and losses are recorded as a component of stockholders’ equity.

Property_Equipment_and_Mine_De1

Property, Equipment and Mine Development Costs (Tables)	9 Months Ended
	Sep. 30, 2013
Property, Plant and Equipment [Abstract]	'
Schedule of property, equipment and development costs	'
	Property, equipment and mine development costs consisted of the following:
		September 30, 2013		December 31, 2012
	Plant and mining equipment	$	3,720,138	$	3,688,516
	Mine development	294,813		304,765
	Office equipment, software and other	65,288		89,510
	Construction in progress	59,828		46,283
	Total property, equipment and mine development costs	4,140,067		4,129,074
	Less accumulated depreciation and amortization	2,242,382		1,910,058
	Total property, equipment and mine development costs, net	$	1,897,685	$	2,219,016

LongTerm_Debt_Tables

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Schedule of Long-term Debt	'
	Long-term debt consisted of the following:
		September 30,			December 31, 2012
		2013
	6.25% senior notes due 2021	$	700,000		$	700,000
	6.00% senior notes due 2019	800,000			800,000
	9.75% senior notes due 2018	500,000			500,000
	Term loan due 2020	621,875			—
	Term loan due 2016	—			540,000
	3.75% convertible senior notes due 2017	345,000			—
	3.25% convertible senior notes due 2015	305,275			536,162
	2.375% convertible senior notes due 2015	102,697			287,500
	Other	81,234			86,203
	Debt discount	(82,329		)	(63,813		)
	Total long-term debt	3,373,752			3,386,052
	Less current portion	(29,016		)	(95,015		)
	Long-term debt, net of current portion	$	3,344,736		$	3,291,037

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	9 Months Ended
	Sep. 30, 2013
Asset Retirement Obligation Disclosure [Abstract]	'
Schedule of changes in the asset retirement obligations	'
	The following table summarizes the changes in asset retirement obligations for the nine months ended September 30, 2013:
	Total asset retirement obligations at December 31, 2012	$	856,701
	Accretion for the period	45,304
	Revisions in estimated cash flows	(269		)
	Expenditures for the period	(31,519		)
	Total asset retirement obligations at September 30, 2013	$	870,217
	Less current portion	(56,774		)
	Long-term portion	$	813,443

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments and Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Schedule of fair values of financial instruments	'
		September 30, 2013
		Carrying			Total Fair		Quoted Prices			Significant		Significant
		Amount			Value		in Active			Other		Unobservable
							Markets			Observable		Inputs
							(Level 1)			Inputs		(Level 3)
										(Level 2)
	6.25% senior notes due 2021	$	700,000		$	570,500	$	570,500		$	—	$	—
	6.00% senior notes due 2019	800,000			666,000		666,000			—		—
	9.75% senior notes due 2018(4)	496,214			511,875		511,875			—		—
	Term loan due 2020(5)	618,911			608,480		—			608,480		—
	3.75% convertible senior notes due 2017(6)	287,337			337,376		337,376			—		—
	3.25% convertible senior notes due 2015(2)	296,942			285,432		285,432			—		—
	2.375% convertible senior notes due 2015(3)	93,114			95,303		95,303			—		—
	Total long-term debt	$	3,292,518		$	3,074,966	$	2,466,486		$	608,480	$	—
		December 31, 2012
		Carrying			Total Fair		Quoted Prices			Significant		Significant
		Amount			Value		in Active			Other		Unobservable
							Markets			Observable		Inputs
							(Level 1)			Inputs		(Level 3)
										(Level 2)
	6.25% senior notes due 2021	$	700,000		$	649,110	$	649,110		$	—	$	—
	6.00% senior notes due 2019	800,000			755,600		755,600			—		—
	9.75% senior notes due 2018(4)	495,161			540,125		540,125			—		—
	Term loan due 2016(1)	539,481			537,316		—			537,316		—
	3.25% convertible senior notes due 2015(2)	515,901			513,375		513,375			—		—
	2.375% convertible senior notes due 2015(3)	249,306			268,094		268,094			—		—
	Total long-term debt	$	3,299,849		$	3,263,620	$	2,726,304		$	537,316	$	—
	(1)	Net of debt discount of $519 as of December 31, 2012.
	(2)	Net of debt discount of $8,332 and $20,261 as of September 30, 2013 and December 31, 2012, respectively.
	(3)	Net of debt discount of $9,584 and $38,194 as of September 30, 2013 and December 31, 2012, respectively.
	(4)	Net of debt discount of $3,786 and $4,839 as of September 30, 2013 and December 31, 2012, respectively.
	(5)	Net of debt discount of $2,964 as of September 30, 2013.
	(6)	Net of debt discount of $57,663 as of September 30, 2013.
Schedule of fair value of assets and liabilities measured on recurring and nonrecurring basis	'
		September 30, 2013
		Total Fair			Quoted Prices		Significant			Significant
		Value			in Active		Other			Unobservable
					Markets		Observable			Inputs
					(Level 1)		Inputs			(Level 3)
							(Level 2)
	Financial assets (liabilities):
	U.S. treasury and agency securities	$	97,097		$	97,097	$	—		$	—
	Mutual funds held in Rabbi Trust	$	8,830		$	8,830	$	—		$	—
	Corporate debt securities	$	255,874		$	—	$	255,874		$	—
	Forward coal sales	$	9,004		$	—	$	9,004		$	—
	Commodity swaps	$	6,118		$	—	$	6,118		$	—
		December 31, 2012
		Total Fair			Quoted Prices		Significant			Significant
		Value			in Active		Other			Unobservable
					Markets		Observable			Inputs
					(Level 1)		Inputs			(Level 3)
							(Level 2)
	Financial assets (liabilities):
	U.S. treasury and agency securities	$	85,568		$	85,568	$	—		$	—
	Mutual funds held in Rabbi Trust	$	8,133		$	8,133	$	—		$	—
	Corporate debt securities	$	212,639		$	—	$	212,639		$	—
	Forward coal sales	$	15,359		$	—	$	15,359		$	—
	Forward coal purchases	$	(4	)	$	—	$	(4	)	$	—
	Commodity swaps	$	7,080		$	—	$	7,080		$	—
	Commodity options	$	138		$	—	$	138		$	—

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of derivative assets at fair value	'
	The following tables present the fair values and location of the Company’s derivative instruments within the Condensed Consolidated Balance Sheets:
				Asset Derivatives
	Derivatives designated as	Statement of Financial Position Location		September 30,			December 31,
	cash flow hedging instruments			2013			2012
	Commodity swaps	Prepaid expenses and other current assets		$	—		$	6,484
	Commodity swaps	Other non-current assets		—			4,718
	Commodity options	Prepaid expenses and other current assets		—			138
				$	—		$	11,340
	Derivatives not designated as	Statement of Financial Position Location		September 30,			December 31,
	cash flow hedging instruments			2013			2012
	Commodity swaps	Prepaid expenses and other current assets		$	6,718		$	—
	Commodity swaps	Other non-current assets		1,714			—
	Forward coal sales	Prepaid expenses and other current assets		8,876			15,359
	Forward coal sales	Other non-current assets		128			—
				$	17,436		$	15,359
	Total asset derivatives			$	17,436		$	26,699
Schedule of derivative liabilities at fair value	'
				Liability Derivatives
	Derivatives designated as	Statement of Financial Position Location		September 30,			December 31,
	cash flow hedging instruments			2013			2012
	Commodity swaps	Accrued expenses and other current liabilities		$	—		$	2,457
	Commodity swaps	Other non-current liabilities		—			972
				$	—		$	3,429
	Derivatives not designated as	Statement of Financial Position Location		September 30,			December 31,
	cash flow hedging instruments			2013			2012
	Commodity swaps	Other non-current liabilities		$	770		$	—
	Forward coal purchases	Accrued expenses and other current liabilities		—			4
	Commodity swaps	Accrued expenses and other current liabilities		1,544			693
				$	2,314		$	697
	Total liability derivatives			$	2,314		$	4,126
Gains and losses on derivatives designated as cash flow hedging instruments	'
	The following tables present the gains and losses from derivative instruments for the nine months ended September 30, 2013 and 2012 and their location within the Condensed Consolidated Financial Statements:
	Derivatives designated as		Gain (loss) reclassified						Gain (loss) recorded
	cash flow hedging instruments		from accumulated other						in accumulated other
			comprehensive income (loss) to earnings						comprehensive income (loss)
			2013			2012			2013			2012
	Commodity swaps(1) (2) (3)		$	3,094		$	9,190		$	(909	)	$	14,715
	Commodity options(1) (2)		(68		)	—			(63		)	(39		)
			$	3,026		$	9,190		$	(972	)	$	14,676
	(1)	Amounts are recorded as a component of cost of coal sales in the Condensed Consolidated Statements of Operations.
	(2)	Net of tax.
	(3)	Ineffectiveness during the period was immaterial.
Gains and losses on derivatives not designated as cash flow hedging instruments	'
	Derivatives not designated as		Gain (loss) recorded in earnings
	cash flow hedging instruments		Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2013			2012			2013			2012
	Forward coal sales(1)		$	(5,149	)	$	(48,131	)	$	(6,354	)	$	5,424
	Forward coal purchases(1)		(4		)	16,723			4			7,391
	Commodity swaps(2)		5,340			625			5,038			377
	Interest rate swap(3)		—			(42		)	—			(372		)
			$	187		$	(30,825	)	$	(1,312	)	$	12,820
	(1)	Amounts are recorded as a component of other revenues in the Condensed Consolidated Statements of Operations.
	(2)	Amounts are recorded as a component of other expenses in the Condensed Consolidated Statements of Operations.
	(3)	Amounts are recorded as a component of interest expense in the Condensed Consolidated Statements of Operations.

Income_Taxes_Tables

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Schedule of reconciliation of statutory federal income tax expense to income from continuing operations before income taxes and the actual income tax expense	'
	A reconciliation of the statutory federal income tax benefit at 35% to the actual income tax benefit is as follows:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Federal statutory income tax benefit	$	(210,482	)	$	(45,265	)	$	(372,306	)	$	(1,010,217	)
	Increases (reductions) in taxes due to:
	Percentage depletion allowance	(7,062		)	(28,255		)	(27,909		)	(61,157		)
	State taxes, net of federal tax impact	(9,151		)	(10,760		)	(19,190		)	(32,490		)
	State statutory tax rate change, net of federal tax impact	(2,524		)	—			(2,524		)	(6,397		)
	Non-deductible fines and penalties	1,253			1,085			12,472			2,909
	Non-deductible goodwill impairment	88,585			—			88,585			506,634
	Change in valuation allowance	(5,070		)	(2,048		)	2,614			20,706
	Other, net	1,314			2,061			9,236			3,247
	Income tax benefit	$	(143,137	)	$	(83,182	)	$	(309,022	)	$	(576,765	)

Employee_Benefit_Plans_Tables

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2013
Defined Benefit Pension Plans	'
Employee Benefit Plans	'
Schedule of components of the net periodic benefit costs (credits)	'
	The components of net periodic benefit costs (credits) are as follows:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Interest cost	$	8,220		$	7,952		$	22,673		$	24,148
	Expected return on plan assets	(10,001		)	(9,815		)	(28,145		)	(28,978		)
	Amortization of net actuarial loss	205			551			712			1,286
	Loss on settlement	—			—			58			—
	Net periodic benefit credits	$	(1,576	)	$	(1,312	)	$	(4,702	)	$	(3,544	)
Postretirement Health Care and Life Insurance Benefits	'
Employee Benefit Plans	'
Schedule of components of the net periodic benefit costs (credits)	'
	The components of net periodic benefit costs are as follows:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Service cost	$	3,329		$	4,381		$	10,612		$	12,465
	Interest cost	10,183			10,748			29,799			32,923
	Amortization of prior service cost (credit)	(955		)	104			(2,864		)	313
	Amortization of net actuarial loss	410			1,749			2,871			3,653
	Net periodic benefit cost	$	12,967		$	16,982		$	40,418		$	49,354
Workers' Compensation and Pneumoconiosis (Black lung)	'
Employee Benefit Plans	'
Schedule of components of the net periodic benefit costs (credits)	'
	The components of net periodic benefit costs are as follows:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Service cost	$	657		$	2,080		$	2,076		$	6,034
	Interest cost	1,691			1,384			4,825			4,228
	Expected return on plan assets	(30		)	(12		)	(46		)	(39		)
	Amortization of net actuarial loss	162			—			780			—
	Net periodic benefit cost	$	2,480		$	3,452		$	7,635		$	10,223

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Schedule of segment operating results and capital expenditures	'
	Segment operating results and capital expenditures for the three months ended September 30, 2013 were as follows:
		Eastern			Western			All			Consolidated
		Coal			Coal			Other
		Operations			Operations
	Total revenues	$	1,050,495		$	128,151		$	12,448		$	1,191,094
	Depreciation, depletion, and amortization	$	175,767		$	13,686		$	6,839		$	196,292
	Amortization of acquired intangibles, net	$	3,434		$	(690	)	$	4		$	2,748
	EBITDA	$	(244,689	)	$	30,478		$	(126,902	)	$	(341,113	)
	Capital expenditures	$	54,725		$	1,047		$	351		$	56,123
	Segment operating results and capital expenditures for the three months ended September 30, 2012 were as follows:
		Eastern			Western			All			Consolidated
		Coal			Coal			Other
		Operations			Operations
	Total revenues	$	1,446,374		$	171,982		$	15,453		$	1,633,809
	Depreciation, depletion, and amortization	$	215,961		$	16,868		$	6,065		$	238,894
	Amortization of acquired intangibles, net	$	(15,940	)	$	3,480		$	778		$	(11,682	)
	EBITDA	$	123,544		$	42,305		$	(21,948	)	$	143,901
	Capital expenditures	$	80,695		$	4,150		$	2,503		$	87,348
	Acquisition of mineral rights under federal lease	$	—		$	17,393		$	—		$	17,393
	Segment operating results and capital expenditures for the nine months ended September 30, 2013 were as follows:
		Eastern			Western			All			Consolidated
		Coal			Coal			Other
		Operations			Operations
	Total revenues	$	3,451,903		$	369,377		$	38,528		$	3,859,808
	Depreciation, depletion, and amortization	$	586,486		$	40,863		$	22,672		$	650,021
	Amortization of acquired intangibles, net	$	2,561		$	(1,666	)	$	13		$	908
	EBITDA	$	(73,936	)	$	74,276		$	(233,689	)	$	(233,349	)
	Capital expenditures	$	156,934		$	4,149		$	2,046		$	163,129
	Segment operating results and capital expenditures for the nine months ended September 30, 2012 were as follows:
		Eastern			Western			All			Consolidated
		Coal			Coal			Other
		Operations			Operations
	Total revenues	$	4,899,430		$	459,320		$	57,781		$	5,416,531
	Depreciation, depletion, and amortization	$	730,894		$	47,284		$	19,338		$	797,516
	Amortization of acquired intangibles, net	$	(78,067	)	$	10,472		$	3,115		$	(64,480	)
	EBITDA	$	(1,978,561	)	$	25,616		$	(64,788	)	$	(2,017,733	)
	Capital expenditures	$	304,010		$	16,927		$	11,655		$	332,592
	Acquisition of mineral rights under federal lease	$	—		$	53,501		$	—		$	53,501
Schedule of reconciliation of EBITDA to net income (loss)	'
	The following table presents a reconciliation of EBITDA to net loss:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	EBITDA	$	(341,113	)	$	143,901		$	(233,349	)	$	(2,017,733	)
	Interest expense	(62,233		)	(47,345		)	(182,587		)	(139,313		)
	Interest income	1,008			1,328			3,133			3,749
	Income tax benefit	143,137			83,182			309,022			576,765
	Depreciation, depletion and amortization	(196,292		)	(238,894		)	(650,021		)	(797,516		)
	Amortization of acquired intangibles, net	(2,748		)	11,682			(908		)	64,480
	Net loss	$	(458,241	)	$	(46,146	)	$	(754,710	)	$	(2,309,568	)
Schedule of Total Assets and Goodwill	'
	The following table presents total assets and goodwill as of September 30, 2013 and December 31, 2012:
		Total Assets						Goodwill
		September 30,			December 31,			September 30,			December 31,
		2013			2012			2013			2012
	Eastern Coal Operations	$	9,817,222		$	10,691,029		$	308,651		$	561,753
	Western Coal Operations	609,905			647,292			—			—
	All Other	1,669,878			1,751,485			—			5,912
	Total	$	12,097,005		$	13,089,806		$	308,651		$	567,665

Asset_Impairment_and_Restructu1

Asset Impairment and Restructuring (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Impaired Intangible Assets And Long-Lived Assets Held And Used [Line Items]	'	'	'	'
Severance Costs	($266)	$7,495	$12,781	$22,931
Restructuring - professional fees and other expenses	393	5,462	9,687	7,493
Asset Impairment Charges	1,890	990,923	'	990,923
Restructuring - reserve for advanced royalties and deposits	'	719	'	7,263
Mining Properties and Mineral Rights [Member]	'	'	'	'
Impaired Intangible Assets And Long-Lived Assets Held And Used [Line Items]	'	'	'	'
Impairment of Long-Lived Assets Held-for-use	'	714,580	'	714,580
Property, plant and equipment	'	'	'	'
Impaired Intangible Assets And Long-Lived Assets Held And Used [Line Items]	'	'	'	'
Impairment of Long-Lived Assets Held-for-use	'	271,827	'	271,827
Other Intangible Assets [Member]	'	'	'	'
Impaired Intangible Assets And Long-Lived Assets Held And Used [Line Items]	'	'	'	'
Impairment of Long-Lived Assets Held-for-use	'	4,516	'	4,516
Eastern Coal Operations [Member]	'	'	'	'
Impaired Intangible Assets And Long-Lived Assets Held And Used [Line Items]	'	'	'	'
Asset Impairment Charges	'	985,346	'	985,346
All Other Segments [Member]	'	'	'	'
Impaired Intangible Assets And Long-Lived Assets Held And Used [Line Items]	'	'	'	'
Asset Impairment Charges	'	$5,577	'	$5,577

Goodwill_net_Goodwill_net_Deta

Goodwill, net Goodwill, net (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Goodwill [Line Items]	'	'	'	'	'	'
Goodwill, Gross	$3,083,528	'	$3,083,528	'	$3,083,528	$3,083,528
Goodwill, Acquired During Period	'	'	0	'	0	'
Goodwill impairment	-253,102	0	-253,102	-1,525,332	-1,713,526	'
Goodwill, Impaired, Accumulated Impairment Loss	-2,774,877	'	-2,774,877	'	-2,515,863	-802,337
Goodwill, Period Increase (Decrease)	'	'	259,014	'	'	'
Goodwill	308,651	'	308,651	'	567,665	2,281,191
Eastern Coal Operations [Member]	'	'	'	'	'	'
Goodwill [Line Items]	'	'	'	'	'	'
Goodwill, Gross	3,024,308	'	3,024,308	'	3,024,308	3,024,308
Goodwill, Acquired During Period	'	'	0	'	0	'
Goodwill impairment	-253,102	'	-253,102	-1,525,332	-1,660,218	'
Goodwill, Impaired, Accumulated Impairment Loss	-2,715,657	'	-2,715,657	'	-2,462,555	-802,337
Goodwill	308,651	'	308,651	'	561,753	2,221,971
Western Coal Operations [Member]	'	'	'	'	'	'
Goodwill [Line Items]	'	'	'	'	'	'
Goodwill, Gross	53,308	'	53,308	'	53,308	53,308
Goodwill, Acquired During Period	'	'	0	'	0	'
Goodwill impairment	'	'	0	'	-53,308	'
Goodwill, Impaired, Accumulated Impairment Loss	-53,308	'	-53,308	'	-53,308	0
Goodwill	0	'	0	'	0	53,308
All Other Segments [Member]	'	'	'	'	'	'
Goodwill [Line Items]	'	'	'	'	'	'
Goodwill, Gross	5,912	'	5,912	'	5,912	5,912
Goodwill, Acquired During Period	'	'	0	'	0	'
Goodwill, Other Changes	'	'	-5,912	'	'	'
Goodwill impairment	'	'	'	'	0	'
Goodwill, Impaired, Accumulated Impairment Loss	-5,912	'	-5,912	'	0	0
Goodwill	$0	'	$0	'	$5,912	$5,912

Goodwill_net_Goodwill_net_Deta1

Goodwill, net Goodwill, net (Details 2) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Goodwill [Line Items]	'	'	'	'	'
Goodwill impairment	$253,102	$0	$253,102	$1,525,332	$1,713,526
Eastern Coal Operations [Member]	'	'	'	'	'
Goodwill [Line Items]	'	'	'	'	'
Goodwill impairment	$253,102	'	$253,102	$1,525,332	$1,660,218

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income - Changes to Accumulated Other Comprehensive Income (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Accumulated Other Comprehensive Income [Roll Forward]	'
Accumulated other comprehensive income (loss) - beginning balance	($166,598)
Other comprehensive income (loss) before reclassifications	107,910
Amounts reclassified from accumulated other comprehensive income (loss)	-2,018
Accumulated other comprehensive income (loss) - ending balance	-60,706
Employee benefit costs	'
Accumulated Other Comprehensive Income [Roll Forward]	'
Accumulated other comprehensive income (loss) - beginning balance	-171,394
Other comprehensive income (loss) before reclassifications	108,985
Amounts reclassified from accumulated other comprehensive income (loss)	946
Accumulated other comprehensive income (loss) - ending balance	-61,463
Cash flow hedges	'
Accumulated Other Comprehensive Income [Roll Forward]	'
Accumulated other comprehensive income (loss) - beginning balance	4,755
Other comprehensive income (loss) before reclassifications	-972
Amounts reclassified from accumulated other comprehensive income (loss)	-3,026
Accumulated other comprehensive income (loss) - ending balance	757
Available-for-sale marketable securities	'
Accumulated Other Comprehensive Income [Roll Forward]	'
Accumulated other comprehensive income (loss) - beginning balance	41
Other comprehensive income (loss) before reclassifications	-103
Amounts reclassified from accumulated other comprehensive income (loss)	62
Accumulated other comprehensive income (loss) - ending balance	$0

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income - Amounts Reclassified from Accumulated Other Comprehensive Income (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reclassification Out Of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Coal revenues	$1,028,847	$1,455,702	$3,292,412	$4,660,541
Cost of coal sales	-988,995	-1,259,174	-3,082,330	-4,080,964
Other revenues	26,316	23,657	119,080	158,833
Interest income	1,008	1,328	3,133	3,749
Income (loss) before income taxes	-601,378	-129,328	-1,063,732	-2,886,333
Income tax (expense) benefit	143,137	83,182	309,022	576,765
Net income (loss)	-458,241	-46,146	-754,710	-2,309,568
Amounts reclassifed from accumulated other comprehensive income (loss) | Employee benefit costs	'	'	'	'
Reclassification Out Of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Amortization of actuarial loss	777	'	4,363	'
Amortization of prior service credit	-955	'	-2,864	'
Other Comprehensive Income/(Loss), reclassification adjustment from AOCI, pension and other post retirement benefit plans, other, before tax	0	'	58	'
Income (loss) before income taxes	-178	'	1,557	'
Income tax (expense) benefit	73	'	-611	'
Net income (loss)	-105	'	946	'
Amounts reclassifed from accumulated other comprehensive income (loss) | Cash flow hedges	'	'	'	'
Reclassification Out Of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Income (loss) before income taxes	-1,734	'	-4,975	'
Income tax (expense) benefit	788	'	1,949	'
Net income (loss)	-946	'	-3,026	'
Amounts reclassifed from accumulated other comprehensive income (loss) | Cash flow hedges | Commodity swaps	'	'	'	'
Reclassification Out Of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Coal revenues	-1,514	'	-3,304	'
Cost of coal sales	-220	'	82	'
Other revenues	0	'	-1,866	'
Amounts reclassifed from accumulated other comprehensive income (loss) | Cash flow hedges | Commodity options	'	'	'	'
Reclassification Out Of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Other revenues	0	'	113	'
Amounts reclassifed from accumulated other comprehensive income (loss) | Available-for-sale marketable securities	'	'	'	'
Reclassification Out Of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Interest income	123	'	103	'
Income tax (expense) benefit	-45	'	-41	'
Net income (loss)	$78	'	$62	'

Earnings_Per_Share_Details

Earnings Per Share (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]	'	'	'	'
Weighted average shares - basic	220,960,449	220,417,448	220,850,020	220,167,198
Weighted average shares - diluted	220,960,449	220,417,448	220,850,020	220,167,198
anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain] | Convertible Debt [Member]	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	3.75%	'	3.75%	'
Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member] | Convertible Debt [Member]	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	2.38%	'	2.38%	'
Three Point Two Five Percent Convertible Senior Notes [Member] | Convertible Debt [Member]	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	3.25%	'	3.25%	'

Inventories_net_Details

Inventories, net (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Raw coal	$38,737	$58,382
Saleable coal	199,460	233,550
Materials, supplies and other, net	94,914	106,128
Total inventories, net	$333,111	$398,060

Marketable_Securities_Details

Marketable Securities (Details) (Prepaid Expenses and Other Current Assets [Member], USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Short-term marketable securities	'		'
Cost	$350,724		$297,389
Unrealized Gain	43		107
Unrealized Loss	-46		-44
Fair value	350,721		297,452
U.S. treasury and agency securities	'		'
Short-term marketable securities	'		'
Cost	97,085		85,537
Unrealized Gain	14	[1]	32	[1]
Unrealized Loss	-2	[1]	-1	[1]
Fair value	97,097		85,568
Corporate debt securities	'		'
Short-term marketable securities	'		'
Cost	253,639		211,852
Unrealized Gain	29	[1]	75	[1]
Unrealized Loss	-44	[1]	-43	[1]
Fair value	$253,624		$211,884
[1]	Unrealized gains and losses are recorded as a component of stockholdersb equity.

Marketable_Securities_Details_

Marketable Securities (Details 2) (USD $)

9 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Minimum

Maximum

Other non-current assets

Other non-current assets

Other non-current assets

Other non-current assets

Other non-current assets

Other non-current assets

Y

Y

Corporate debt securities

Corporate debt securities

Mutual funds held in rabbi trusts

Mutual funds held in rabbi trusts

Long-term marketable securities

'

'

'

'

'

'

'

'

Long-term marketable securities maturity period

1

2

'

'

'

'

'

'

Cost

'

'

$9,527

$8,298

$2,250

$754

$7,277

$7,544

Unrealized Gain

'

'

3,111

2,085

0

[1]

1

[1]

3,111

[2]

2,084

[2]

Unrealized Loss

'

'

-1,558

-1,495

0

[1]

0

[1]

-1,558

[2]

-1,495

[2]

Fair value

'

'

$11,080

$8,888

$2,250

$755

$8,830

$8,133

[1]

Unrealized gains and losses are recorded as a component of stockholdersb equity.

[2]

Unrealized gains and losses are recorded in current period earnings.

Property_Equipment_and_Mine_De2

Property, Equipment and Mine Development Costs (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Property, equipment, and mine development costs	'	'
Total property, equipment and mine development costs	$4,140,067	$4,129,074
Less accumulated depreciation and amortization	2,242,382	1,910,058
Total property, equipment and mine development costs, net	1,897,685	2,219,016
Plant and mining equipment	'	'
Property, equipment, and mine development costs	'	'
Total property, equipment and mine development costs	3,720,138	3,688,516
Mine development	'	'
Property, equipment, and mine development costs	'	'
Total property, equipment and mine development costs	294,813	304,765
Office equipment and software	'	'
Property, equipment, and mine development costs	'	'
Total property, equipment and mine development costs	65,288	89,510
Construction in progress	'	'
Property, equipment, and mine development costs	'	'
Total property, equipment and mine development costs	$59,828	$46,283

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Long-Term Debt	'	'
Debt Instrument, Unamortized Discount (Premium), Net	$82,329	$63,813
Total long-term debt	3,373,752	3,386,052
Less current portion	-29,016	-95,015
Long-term debt, net of current portion	3,344,736	3,291,037
Six Point Two Five Percent Senior Notes Due Twenty Twenty One [Member]	'	'
Long-Term Debt	'	'
Carrying amount of debt	700,000	700,000
Debt Instrument, Interest Rate, Stated Percentage	6.25%	'
Six Point Zero Zero Percent Senior Notes Due Twenty Nineteen [Member]	'	'
Long-Term Debt	'	'
Carrying amount of debt	800,000	800,000
Debt Instrument, Interest Rate, Stated Percentage	6.00%	'
Nine Point Seven Five Percent Senior Notes Due Twenty Eighteen [Member]	'	'
Long-Term Debt	'	'
Carrying amount of debt	500,000	500,000
Debt Instrument, Unamortized Discount (Premium), Net	3,786	4,839
Debt Instrument, Interest Rate, Stated Percentage	9.75%	'
anr_TermLoanDueTwentyTwenty [Member]	'	'
Long-Term Debt	'	'
Carrying amount of debt	621,875	0
Debt Instrument, Unamortized Discount (Premium), Net	2,964	'
Term Loan Due Twenty Sixteen [Member]	'	'
Long-Term Debt	'	'
Carrying amount of debt	0	540,000
Debt Instrument, Unamortized Discount (Premium), Net	'	519
anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]	'	'
Long-Term Debt	'	'
Debt Instrument, Unamortized Discount (Premium), Net	57,663	'
Total long-term debt	287,337	'
Three Point Two Five Percent Convertible Senior Notes [Member]	'	'
Long-Term Debt	'	'
Debt Instrument, Unamortized Discount (Premium), Net	8,332	20,261
Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]	'	'
Long-Term Debt	'	'
Debt Instrument, Unamortized Discount (Premium), Net	9,584	38,194
Other	'	'
Long-Term Debt	'	'
Carrying amount of debt	81,234	86,203
Convertible Debt [Member] | Six Point Two Five Percent Senior Notes Due Twenty Twenty One [Member]	'	'
Long-Term Debt	'	'
Debt Instrument, Interest Rate, Stated Percentage	6.25%	'
Convertible Debt [Member] | Six Point Zero Zero Percent Senior Notes Due Twenty Nineteen [Member]	'	'
Long-Term Debt	'	'
Debt Instrument, Interest Rate, Stated Percentage	6.00%	'
Convertible Debt [Member] | Nine Point Seven Five Percent Senior Notes Due Twenty Eighteen [Member]	'	'
Long-Term Debt	'	'
Debt Instrument, Interest Rate, Stated Percentage	9.75%	'
Convertible Debt [Member] | anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]	'	'
Long-Term Debt	'	'
Carrying amount of debt	345,000	0
Debt Instrument, Interest Rate, Stated Percentage	3.75%	'
Convertible Debt [Member] | Three Point Two Five Percent Convertible Senior Notes [Member]	'	'
Long-Term Debt	'	'
Carrying amount of debt	305,275	536,162
Debt Instrument, Interest Rate, Stated Percentage	3.25%	'
Convertible Debt [Member] | Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]	'	'
Long-Term Debt	'	'
Carrying amount of debt	$102,697	$287,500
Debt Instrument, Interest Rate, Stated Percentage	2.38%	'

LongTerm_Debt_LongTerm_Debt_De

Long-Term Debt Long-Term Debt (Details 2) (USD $)

0 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

0 Months Ended

22-May-13

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Sep. 30, 2013

22-May-13

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

22-May-13

Sep. 30, 2013

22-May-13

Sep. 30, 2013

13-May-13

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

13-May-13

Dec. 31, 2012

Sep. 30, 2013

13-May-13

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Aug. 22, 2013

Sep. 30, 2013

Aug. 22, 2013

Sep. 30, 2013

22-May-13

22-May-13

22-May-13

22-May-13

Oct. 02, 2013

22-May-13

Oct. 02, 2013

anr_TermLoanDueTwentyTwenty [Member]

anr_TermLoanDueTwentyTwenty [Member]

Term Loan Due Twenty Sixteen [Member]

Term Loan Due Twenty Sixteen [Member]

Senior Secured Revolving Credit Facility [Member]

Senior Secured Revolving Credit Facility [Member]

Accounts Receivable Securitization Facility

Accounts Receivable Securitization Facility

anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]

anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]

Nine Point Seven Five Percent Senior Notes Due Twenty Eighteen [Member]

Nine Point Seven Five Percent Senior Notes Due Twenty Eighteen [Member]

Three Point Two Five Percent Convertible Senior Notes [Member]

Three Point Two Five Percent Convertible Senior Notes [Member]

Three Point Two Five Percent Convertible Senior Notes [Member]

Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]

Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]

Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Convertible Debt [Member]

Libor [Member]

Base Rate [Member]

Remainder Of Fiscal Year [Member]

Next Fiscal Year [Member]

Next Fiscal Year (Year Two) [Member]

Next Fiscal Year (Year Two) [Member]

Next Fiscal Year (Year Three) [Member]

anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]

Nine Point Seven Five Percent Senior Notes Due Twenty Eighteen [Member]

Three Point Two Five Percent Convertible Senior Notes [Member]

Three Point Two Five Percent Convertible Senior Notes [Member]

Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]

Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]

2.375% and 3.25% Convertible Senior Notes [Member]

anr_TermLoanDueTwentyTwenty [Member]

anr_TermLoanDueTwentyTwenty [Member]

anr_TermLoanDueTwentyTwenty [Member]

anr_TermLoanDueTwentyTwenty [Member]

anr_TermLoanDueTwentyTwenty [Member]

anr_TermLoanDueTwentyTwenty [Member]

anr_TermLoanDueTwentyTwenty [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Maximum Borrowing Capacity

'

'

'

'

'

'

'

$625,000,000

'

'

$1,100,000,000

'

'

$275,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest Coverage Ratio Before Modification

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2.25

2.5

2

2.5

2

Interest Coverage Ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.5

1.5

1.25

2

1.5

Senior Secured Leverage Ratio

'

'

'

'

'

'

'

2.5

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Rate of Amortization of Quarterly Installments

'

'

'

'

'

'

'

1.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Basis Spread on Variable Rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2.75%

1.75%

'

'

'

'

'

Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.75%

1.75%

'

'

'

'

'

Letters of Credit Outstanding, Amount

'

'

'

'

'

'

'

'

'

'

150,621,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Minimum Liquidity Covenant, Amount Before Amendment

500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt, Gross

525,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loss on early extinguishment of debt

'

-158,000

0

33,039,000

0

'

'

'

-9,044,000

'

'

'

1,358,000

'

'

'

'

'

'

'

'

'

'

'

22,795,000

'

'

'

'

'

0

'

'

'

'

'

'

'

Line of Credit Facility Maximum Borrowing Capacity before Increase

'

'

'

'

'

'

'

'

'

'

'

1,000,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Minimum Liquidity Covenant, Amount

'

300,000,000

'

300,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Interest Rate, Stated Percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9.75%

'

'

'

'

'

'

'

3.75%

9.75%

3.25%

'

2.38%

'

'

'

'

'

'

'

'

'

Initial conversion price equivalent to initial conversion rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$10.10

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Minimum percentage of holders required to declare principal and any accrued and unpaid interest thereon immediately due and payable

'

'

'

'

'

'

'

'

'

'

'

'

'

'

25.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Conversion Ratio

'

'

'

'

'

'

'

'

'

'

'

'

'

'

99.0589

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument Principal Amount Per Share

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Effective Interest Rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8.49%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt and Capital Lease Obligations

'

3,373,752,000

'

3,373,752,000

'

3,386,052,000

'

'

'

'

'

'

'

'

287,337,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Unamortized Discount (Premium), Net

'

82,329,000

'

82,329,000

'

63,813,000

2,964,000

'

'

519,000

'

'

'

'

57,663,000

'

3,786,000

4,839,000

8,332,000

'

20,261,000

9,584,000

'

38,194,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Convertible, Carrying Amount of Equity Component

'

'

'

'

'

'

'

'

'

'

'

'

'

'

61,949,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Repurchased Face Amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

225,787,000

'

'

181,403,000

'

'

'

'

5,100,000

'

3,400,000

'

'

'

'

'

'

'

'

Debt Instrument, Face Amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$345,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Changes in the asset retirement obligations	'	'
Total asset retirement obligations at beginning of year	$856,701	'
Accretion for the period	45,304	'
Revisions in estimated cash flows	-269	'
Expenditures for the period	-31,519	'
Total asset retirement obligations at end of period	870,217	'
Less current portion	-56,774	'
Long-term portion	$813,443	$763,482

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments and Fair Value Measurements (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Fair value of financial instruments	'		'
Long-term debt	$3,344,736		$3,291,037
Debt Instrument, Unamortized Discount (Premium), Net	82,329		63,813
Six Point Two Five Percent Senior Notes Due Twenty Twenty One [Member]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Interest Rate, Stated Percentage	6.25%		'
Six Point Zero Zero Percent Senior Notes Due Twenty Nineteen [Member]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Interest Rate, Stated Percentage	6.00%		'
Nine Point Seven Five Percent Senior Notes Due Twenty Eighteen [Member]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Interest Rate, Stated Percentage	9.75%		'
Debt Instrument, Unamortized Discount (Premium), Net	3,786		4,839
anr_TermLoanDueTwentyTwenty [Member]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Unamortized Discount (Premium), Net	2,964		'
Term Loan Due Twenty Sixteen [Member]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Unamortized Discount (Premium), Net	'		519
anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Unamortized Discount (Premium), Net	57,663		'
Three Point Two Five Percent Convertible Senior Notes [Member]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Unamortized Discount (Premium), Net	8,332		20,261
Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Unamortized Discount (Premium), Net	9,584		38,194
Convertible Debt [Member] | Six Point Two Five Percent Senior Notes Due Twenty Twenty One [Member]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Interest Rate, Stated Percentage	6.25%		'
Convertible Debt [Member] | Six Point Zero Zero Percent Senior Notes Due Twenty Nineteen [Member]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Interest Rate, Stated Percentage	6.00%		'
Convertible Debt [Member] | Nine Point Seven Five Percent Senior Notes Due Twenty Eighteen [Member]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Interest Rate, Stated Percentage	9.75%		'
Convertible Debt [Member] | anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Interest Rate, Stated Percentage	3.75%		'
Convertible Debt [Member] | Three Point Two Five Percent Convertible Senior Notes [Member]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Interest Rate, Stated Percentage	3.25%		'
Convertible Debt [Member] | Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]	'		'
Fair value of financial instruments	'		'
Debt Instrument, Interest Rate, Stated Percentage	2.38%		'
Carrying Amount	'		'
Fair value of financial instruments	'		'
Long-term debt	3,292,518		3,299,849
Carrying Amount | Six Point Two Five Percent Senior Notes Due Twenty Twenty One [Member]	'		'
Fair value of financial instruments	'		'
Long-term debt	700,000		700,000
Carrying Amount | Six Point Zero Zero Percent Senior Notes Due Twenty Nineteen [Member]	'		'
Fair value of financial instruments	'		'
Long-term debt	800,000		800,000
Carrying Amount | Nine Point Seven Five Percent Senior Notes Due Twenty Eighteen [Member]	'		'
Fair value of financial instruments	'		'
Long-term debt	496,214		495,161	[1]
Carrying Amount | Term Loan Due Twenty Sixteen [Member]	'		'
Fair value of financial instruments	'		'
Long-term debt	618,911	[2]	539,481	[2]
Carrying Amount | Convertible Debt [Member] | anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]	'		'
Fair value of financial instruments	'		'
Long-term debt	287,337	[3]	'
Carrying Amount | Convertible Debt [Member] | Three Point Two Five Percent Convertible Senior Notes [Member]	'		'
Fair value of financial instruments	'		'
Long-term debt	296,942	[3]	515,901	[3]
Carrying Amount | Convertible Debt [Member] | Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]	'		'
Fair value of financial instruments	'		'
Long-term debt	93,114	[4]	249,306	[4]
Fair Value	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	3,074,966		3,263,620
Fair Value | Six Point Two Five Percent Senior Notes Due Twenty Twenty One [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	570,500		649,110
Fair Value | Six Point Zero Zero Percent Senior Notes Due Twenty Nineteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	666,000		755,600
Fair Value | Nine Point Seven Five Percent Senior Notes Due Twenty Eighteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	511,875		540,125	[1]
Fair Value | Term Loan Due Twenty Sixteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	608,480	[2]	537,316	[2]
Fair Value | Convertible Debt [Member] | anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	337,376	[2]	'
Fair Value | Convertible Debt [Member] | Three Point Two Five Percent Convertible Senior Notes [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	285,432	[3]	513,375	[3]
Fair Value | Convertible Debt [Member] | Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	95,303	[4]	268,094	[4]
Quoted Prices in Active Market for Identical Assets (Level 1) | Fair Value	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	2,466,486		2,726,304
Quoted Prices in Active Market for Identical Assets (Level 1) | Fair Value | Six Point Two Five Percent Senior Notes Due Twenty Twenty One [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	570,500		649,110
Quoted Prices in Active Market for Identical Assets (Level 1) | Fair Value | Six Point Zero Zero Percent Senior Notes Due Twenty Nineteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	666,000		755,600
Quoted Prices in Active Market for Identical Assets (Level 1) | Fair Value | Nine Point Seven Five Percent Senior Notes Due Twenty Eighteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	511,875		540,125	[1]
Quoted Prices in Active Market for Identical Assets (Level 1) | Fair Value | Term Loan Due Twenty Sixteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0	[2]	0	[2]
Quoted Prices in Active Market for Identical Assets (Level 1) | Fair Value | Convertible Debt [Member] | anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	337,376	[2]	'
Quoted Prices in Active Market for Identical Assets (Level 1) | Fair Value | Convertible Debt [Member] | Three Point Two Five Percent Convertible Senior Notes [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	285,432	[3]	513,375	[3]
Quoted Prices in Active Market for Identical Assets (Level 1) | Fair Value | Convertible Debt [Member] | Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	95,303	[4]	268,094	[4]
Significant Observable Inputs (Level 2) | Fair Value	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	608,480		537,316
Significant Observable Inputs (Level 2) | Fair Value | Six Point Two Five Percent Senior Notes Due Twenty Twenty One [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0		0
Significant Observable Inputs (Level 2) | Fair Value | Six Point Zero Zero Percent Senior Notes Due Twenty Nineteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0		0
Significant Observable Inputs (Level 2) | Fair Value | Nine Point Seven Five Percent Senior Notes Due Twenty Eighteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0		0	[1]
Significant Observable Inputs (Level 2) | Fair Value | Term Loan Due Twenty Sixteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	608,480	[2]	537,316	[2]
Significant Observable Inputs (Level 2) | Fair Value | Convertible Debt [Member] | anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0	[2]	'
Significant Observable Inputs (Level 2) | Fair Value | Convertible Debt [Member] | Three Point Two Five Percent Convertible Senior Notes [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0	[3]	0	[3]
Significant Observable Inputs (Level 2) | Fair Value | Convertible Debt [Member] | Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0	[4]	0	[4]
Fair Value, Inputs, Level 3 [Member] | Fair Value	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value | Six Point Two Five Percent Senior Notes Due Twenty Twenty One [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value | Six Point Zero Zero Percent Senior Notes Due Twenty Nineteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value | Nine Point Seven Five Percent Senior Notes Due Twenty Eighteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0		0	[1]
Fair Value, Inputs, Level 3 [Member] | Fair Value | Term Loan Due Twenty Sixteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0	[2]	0	[2]
Fair Value, Inputs, Level 3 [Member] | Fair Value | Convertible Debt [Member] | anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0	[2]	'
Fair Value, Inputs, Level 3 [Member] | Fair Value | Convertible Debt [Member] | Three Point Two Five Percent Convertible Senior Notes [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	0	[3]	0	[3]
Fair Value, Inputs, Level 3 [Member] | Fair Value | Convertible Debt [Member] | Two Point Three Seven Five Percent Convertible Senior Notes Due Twenty Fifteen [Member]	'		'
Fair value of financial instruments	'		'
Fair value of long-term debt	$0	[4]	$0	[4]
[1]	(4)B Net of debt discount of $3,786 and $4,839 as of SeptemberB 30, 2013 and DecemberB 31, 2012, respectively.
[2]	Net of debt discount of $519 as of DecemberB 31, 2012.
[3]	Net of debt discount of $8,332 and $20,261 as of SeptemberB 30, 2013 and DecemberB 31, 2012, respectively.
[4]	Net of debt discount of $9,584 and $38,194 as of SeptemberB 30, 2013 and DecemberB 31, 2012, respectively.

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments and Fair Value Measurements (Details 2) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Total Fair Value | Forward coal sales	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	$9,004	$15,359
Total Fair Value | Forward coal purchases	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, liabilities	'	-4
Total Fair Value | Commodity swaps	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	6,118	7,080
Total Fair Value | Commodity options	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	'	138
Total Fair Value | U.S. treasury and agency securities	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	97,097	85,568
Total Fair Value | Mutual funds held in rabbi trust	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	8,830	8,133
Total Fair Value | Corporate debt securities	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	255,874	212,639
Quoted Prices in Active Market for Identical Assets (Level 1) | Forward coal sales	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	0	0
Quoted Prices in Active Market for Identical Assets (Level 1) | Forward coal purchases	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, liabilities	'	0
Quoted Prices in Active Market for Identical Assets (Level 1) | Commodity swaps	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	0	0
Quoted Prices in Active Market for Identical Assets (Level 1) | Commodity options	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	'	0
Quoted Prices in Active Market for Identical Assets (Level 1) | U.S. treasury and agency securities	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	97,097	85,568
Quoted Prices in Active Market for Identical Assets (Level 1) | Mutual funds held in rabbi trust	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	8,830	8,133
Quoted Prices in Active Market for Identical Assets (Level 1) | Corporate debt securities	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	0	0
Significant Observable Inputs (Level 2) | Forward coal sales	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	9,004	15,359
Significant Observable Inputs (Level 2) | Forward coal purchases	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, liabilities	'	-4
Significant Observable Inputs (Level 2) | Commodity swaps	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	6,118	7,080
Significant Observable Inputs (Level 2) | Commodity options	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	'	138
Significant Observable Inputs (Level 2) | U.S. treasury and agency securities	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	0	0
Significant Observable Inputs (Level 2) | Mutual funds held in rabbi trust	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	0	0
Significant Observable Inputs (Level 2) | Corporate debt securities	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	255,874	212,639
Fair Value, Inputs, Level 3 [Member] | Forward coal sales	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	0	0
Fair Value, Inputs, Level 3 [Member] | Forward coal purchases	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, liabilities	'	0
Fair Value, Inputs, Level 3 [Member] | Commodity swaps	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	0	0
Fair Value, Inputs, Level 3 [Member] | Commodity options	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	'	0
Fair Value, Inputs, Level 3 [Member] | U.S. treasury and agency securities	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	0	0
Fair Value, Inputs, Level 3 [Member] | Mutual funds held in rabbi trust	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	0	0
Fair Value, Inputs, Level 3 [Member] | Corporate debt securities	'	'
Fair value of assets and liabilities measured on recurring and nonrecurring basis	'	'
Total fair value, assets	$0	$0

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Percentage of diesel fuel to cost of coal sales	6.00%
Derivative [Line Items]	'
Expected reclassification of gain (loss) on derivatives to earnings within the next twelve months	$3,081
Commodity swaps | Remainder Of Fiscal Year [Member]	'
Derivative [Line Items]	'
Hedging of cash flows related to anticipated diesel fuel usage, percentage	66.00%
Average fixed price per swap per gallon for diesel fuel hedges	3.03
Commodity swaps | Next Fiscal Year (Year Two) [Member]	'
Derivative [Line Items]	'
Hedging of cash flows related to anticipated diesel fuel usage, percentage	55.00%
Average fixed price per swap per gallon for diesel fuel hedges	2.82

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Details 2) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair value of derivative instruments	'	'
Total asset derivatives	$17,436	$26,699
Designated as cash flow hedging instruments	'	'
Fair value of derivative instruments	'	'
Total asset derivatives	0	11,340
Designated as cash flow hedging instruments | Commodity swaps | Prepaid Expenses and Other Current Assets [Member]	'	'
Fair value of derivative instruments	'	'
Total asset derivatives	0	6,484
Designated as cash flow hedging instruments | Commodity swaps | Other non-current assets	'	'
Fair value of derivative instruments	'	'
Total asset derivatives	0	4,718
Designated as cash flow hedging instruments | Commodity options | Prepaid Expenses and Other Current Assets [Member]	'	'
Fair value of derivative instruments	'	'
Total asset derivatives	0	138
Not designated as cash flow hedging instruments	'	'
Fair value of derivative instruments	'	'
Total asset derivatives	17,436	15,359
Not designated as cash flow hedging instruments | Commodity swaps | Prepaid Expenses and Other Current Assets [Member]	'	'
Fair value of derivative instruments	'	'
Total asset derivatives	6,718	'
Not designated as cash flow hedging instruments | Commodity swaps | Other non-current assets	'	'
Fair value of derivative instruments	'	'
Total asset derivatives	1,714	'
Not designated as cash flow hedging instruments | Forward coal sales | Prepaid Expenses and Other Current Assets [Member]	'	'
Fair value of derivative instruments	'	'
Total asset derivatives	8,876	15,359
Not designated as cash flow hedging instruments | Forward coal sales | Other non-current assets	'	'
Fair value of derivative instruments	'	'
Total asset derivatives	$128	$0

Derivative_Financial_Instrumen4

Derivative Financial Instruments (Details 3) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair value of derivative instruments	'	'
Total liability derivatives	$2,314	$4,126
Designated as cash flow hedging instruments	'	'
Fair value of derivative instruments	'	'
Total liability derivatives	0	3,429
Designated as cash flow hedging instruments | Commodity swaps | Accrued expenses and other current liabilities	'	'
Fair value of derivative instruments	'	'
Total liability derivatives	0	2,457
Designated as cash flow hedging instruments | Commodity swaps | Other non-current liabilities	'	'
Fair value of derivative instruments	'	'
Total liability derivatives	0	972
Not designated as cash flow hedging instruments	'	'
Fair value of derivative instruments	'	'
Total liability derivatives	2,314	697
Not designated as cash flow hedging instruments | Commodity swaps | Accrued expenses and other current liabilities	'	'
Fair value of derivative instruments	'	'
Total liability derivatives	1,544	693
Not designated as cash flow hedging instruments | Commodity swaps | Other non-current liabilities	'	'
Fair value of derivative instruments	'	'
Total liability derivatives	770	'
Not designated as cash flow hedging instruments | Forward coal purchases | Accrued expenses and other current liabilities	'	'
Fair value of derivative instruments	'	'
Total liability derivatives	$0	$4

Derivative_Financial_Instrumen5

Derivative Financial Instruments (Details 4) (Designated as cash flow hedging instruments, USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012
Gains and losses from derivative instruments	'		'
Gain (loss) reclassified from accumulated other comprehensive income (loss) to earnings	$3,026		$9,190
Gain (loss) recorded in accumulated other comprehensive income (loss)	-972		14,676
Commodity swaps	'		'
Gains and losses from derivative instruments	'		'
Gain (loss) reclassified from accumulated other comprehensive income (loss) to earnings	3,094	[1],[2],[3]	9,190	[1],[2],[3]
Gain (loss) recorded in accumulated other comprehensive income (loss)	-909	[1],[2],[3]	14,715	[1],[2],[3]
Commodity options	'		'
Gains and losses from derivative instruments	'		'
Gain (loss) reclassified from accumulated other comprehensive income (loss) to earnings	-68	[1],[2]	0	[1],[2]
Gain (loss) recorded in accumulated other comprehensive income (loss)	($63)	[1],[2]	($39)	[1],[2]
[1]	Amounts are recorded as a component of cost of coal sales in the Condensed Consolidated Statements of Operations.
[2]	Net of tax.
[3]	Ineffectiveness during the period was immaterial.

Derivative_Financial_Instrumen6

Derivative Financial Instruments (Details 5) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Gains and losses from derivative instruments	'		'		'		'
Gain (loss) recorded in earnings	$187		($30,825)		($1,312)		$12,820
Not designated as cash flow hedging instruments | Forward coal sales	'		'		'		'
Gains and losses from derivative instruments	'		'		'		'
Gain (loss) recorded in earnings	-5,149	[1]	-48,131	[1]	-6,354	[1]	5,424	[1]
Not designated as cash flow hedging instruments | Forward coal purchases	'		'		'		'
Gains and losses from derivative instruments	'		'		'		'
Gain (loss) recorded in earnings	-4	[1]	16,723	[1]	4	[1]	7,391	[1]
Not designated as cash flow hedging instruments | Commodity swaps	'		'		'		'
Gains and losses from derivative instruments	'		'		'		'
Gain (loss) recorded in earnings	5,340	[2]	625	[2]	5,038	[2]	377	[2]
Not designated as cash flow hedging instruments | Interest rate swap	'		'		'		'
Gains and losses from derivative instruments	'		'		'		'
Gain (loss) recorded in earnings	$0	[3]	($42)	[3]	$0	[3]	($372)	[3]
[1]	Amounts are recorded as a component of other revenues in the Condensed Consolidated Statements of Operations.
[2]	Amounts are recorded as a component of other expenses in the Condensed Consolidated Statements of Operations.
[3]	Amounts are recorded as a component of interest expense in the Condensed Consolidated Statements of Operations.

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Tax Disclosure [Abstract]	'	'	'	'
Statutory federal income tax rate	35.00%	35.00%	35.00%	35.00%
Reconciliation of statutory federal income tax expense to income from continuing operations before income taxes and the actual income tax expense	'	'	'	'
Federal statutory income tax expense (benefit)	($210,482)	($45,265)	($372,306)	($1,010,217)
Increases (reductions) in taxes due to:	'	'	'	'
Percentage depletion allowance	-7,062	-28,255	-27,909	-61,157
State taxes, net of federal tax impact	-9,151	-10,760	-19,190	-32,490
Income Tax Reconciliation, Change in Enacted Tax Rate	-2,524	0	-2,524	-6,397
Income Tax Reconciliation, Nondeductible Expense, Other	1,253	1,085	12,472	2,909
Income Tax Reconciliation, Nondeductible Expense, Impairment Losses	88,585	0	88,585	506,634
Change in valuation allowance	-5,070	-2,048	2,614	20,706
Other, net	1,314	2,061	9,236	3,247
Income tax expense (benefit)	($143,137)	($83,182)	($309,022)	($576,765)

Employee_Benefit_Plans_Details

Employee Benefit Plans (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Employee Benefit Plans	'	'	'	'
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.59%	'	4.59%	'
Company Administered Defined Benefit Pension Plans	'	'	'	'
Components of net periodic benefit cost	'	'	'	'
Interest cost	$8,220	$7,952	$22,673	$24,148
Expected return on plan assets	-10,001	-9,815	-28,145	-28,978
Amortization of net actuarial (gain) loss	205	551	712	1,286
Gain on settlement	0	0	58	0
Net periodic benefit cost (credit)	-1,576	-1,312	-4,702	-3,544
Defined Benefit Plan, Other Changes	60,267	'	'	'
Company Administered Postretirement Health Care and Life Insurance Benefits	'	'	'	'
Components of net periodic benefit cost	'	'	'	'
Service cost	3,329	4,381	10,612	12,465
Interest cost	10,183	10,748	29,799	32,923
Amortization of prior service cost (credit)	-955	104	-2,864	313
Amortization of net actuarial (gain) loss	410	1,749	2,871	3,653
Net periodic benefit cost (credit)	12,967	16,982	40,418	49,354
Defined Benefit Plan, Other Changes	107,542	'	'	'
Workers' Compensation and Pneumoconiosis (Black lung)	'	'	'	'
Components of net periodic benefit cost	'	'	'	'
Service cost	657	2,080	2,076	6,034
Interest cost	1,691	1,384	4,825	4,228
Expected return on plan assets	-30	-12	-46	-39
Amortization of net actuarial (gain) loss	162	0	780	0
Net periodic benefit cost (credit)	2,480	3,452	7,635	10,223
Defined Benefit Plan, Other Changes	$9,915	'	'	'

StockBased_Compensation_Awards1

Stock-Based Compensation Awards (Details)	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	22-May-13	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
	award	Time-based restricted share units	Performance-based restricted share units	Long-term Incentive Plan 2012 [Member]	Long-term Incentive Plan 2012 [Member]	Stock Plans	Stock Plans	Stock Plans	Stock Plans
						Time-based restricted share units	Performance-based restricted share units	Performance-based restricted share units	Performance-based restricted share units
								Minimum	Maximum
Share-based Compensation Arrangement	'	'	'	'	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	'	'	'	3,600,000	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	'	'	'	'	10,000,000	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	'	'	'	'	4,265,659	'	'	'	'
Number of shares issued	'	'	'	'	'	1,599,386	1,531,787	'	'
Vesting period	'	'3 years	'3 years	'	'	'3 years	'3 years	'	'
Percentage of targeted amount potentially distributed, depending on satisfaction of performance criteria	'	'	'	'	'	'	'	0.00%	200.00%
Number of types of awards	2	'	'	'	'	'	'	'	'

StockBased_Compensation_Awards2

Stock-Based Compensation Awards (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock-Based Compensation Awards	'	'	'	'
Allocated Share-based Compensation Expense	$5,762	$6,409	$18,360	$3,945
Number of common shares repurchased to satisfy employees' minimum statutory withholdings	'	'	165,709	381,969
Average price per share of the common stock repurchased	'	'	$8.16	$18.29
Selling, general and administrative expenses	'	'	'	'
Stock-Based Compensation Awards	'	'	'	'
Percentage of allocated stock-based compensation expense	73.00%	76.00%	77.00%	15.00%
Cost of coal sales	'	'	'	'
Stock-Based Compensation Awards	'	'	'	'
Percentage of allocated stock-based compensation expense	27.00%	24.00%	23.00%	85.00%

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)

0 Months Ended

1 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

1 Months Ended

9 Months Ended

0 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

0 Months Ended

1 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2012

Nov. 30, 2010

Aug. 31, 2002

Sep. 30, 2013

Mar. 31, 2013

Sep. 30, 2012

Sep. 30, 2013

Aug. 31, 2012

Sep. 30, 2013

Mar. 01, 2012

Jan. 31, 2012

Jul. 31, 2011

Sep. 30, 2013

Sep. 30, 2013

Oct. 19, 2012

Jun. 28, 2012

Apr. 30, 2010

Sep. 30, 2013

Nov. 01, 2012

Apr. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Jun. 01, 2011

31-May-11

Apr. 30, 2010

Apr. 16, 2010

Jan. 31, 2012

Sep. 30, 2013

Jul. 16, 2012

9-May-12

Apr. 16, 2012

Mar. 20, 2012

Jul. 31, 2011

Jul. 31, 2011

environmental_group

case

t

Alpha Appalachia Holdings, Inc. (Formerly Massey)

Alpha Appalachia Holdings, Inc. (Formerly Massey)

Alpha Appalachia Holdings, Inc. (Formerly Massey)

Alpha Appalachia Holdings, Inc. (Formerly Massey)

Federal Securities Class Action

Federal Securities Class Action

Damage From Explosion at Upper Big Branch Mine

Damage From Explosion at Upper Big Branch Mine

Damage From Explosion at Upper Big Branch Mine

Damage From Explosion at Upper Big Branch Mine

Wrongful Death and Personal Injury

Wrongful Death and Personal Injury

Wrongful Death and Personal Injury

Wrongful Death and Personal Injury

Uniform Fraudulent Transfers Act Action

Derivative Litigation and Related Class Action Litigation

Derivative Litigation and Related Class Action Litigation

Derivative Litigation and Related Class Action Litigation

Derivative Litigation and Related Class Action Litigation

Well Water Suit

Mine Water Discharge Suits

Mine Water Discharge Suits

Mine Water Discharge Suits

Mine Water Discharge Suits

Compensatory and Economic Damages

Punitive Damages

case

Subsidiary

Subsidiary

case

Miner

Employees

Miner

Injury

Alpha Appalachia Holdings, Inc. (Formerly Massey)

Alpha Appalachia Holdings, Inc. (Formerly Massey)

Alpha Appalachia Holdings, Inc. (Formerly Massey)

Alpha Appalachia Holdings, Inc. (Formerly Massey)

plaintiffs

plaintiffs

plaintiffs

Alpha Appalachia Holdings, Inc. (Formerly Massey)

Rawls Sales & Processing Co.

case

case

case

Subsidiary

Alpha Appalachia Holdings, Inc. (Formerly Massey)

Alpha Appalachia Holdings, Inc. (Formerly Massey)

Employees

Families

Employees

Mediator

Subsidiary

Subsidiary

Subsidiary

case

Families

Families

Loss Contingencies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Range of possible loss, portion not accrued

'

'

'

$350,000

'

'

$350,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proven And Probable Coal Reserves Under LBA

'

'

'

'

'

'

'

222,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Annual installments of lease payments

'

'

'

'

'

'

'

42,130

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

(Income) expense recognized in period

'

'

'

116,552

'

7,893

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of consolidated purported class actions

'

'

'

'

'

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of cases after consolidation of class actions

'

'

'

'

'

'

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of miners killed in explosion

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

29

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of miners injured in explosion

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of individuals who claim to have been injured and filed a petition to amend or set aside agreement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

16

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of miners whose estates have filed an action

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of families of the deceased miners filing wrongful death suits

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of families of deceased miners

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

29

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of seriously injured employees filing personal injury claims

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of employees who filed lawsuits against the Company's subsidiary alleging emotional distress or personal injuries

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

39

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of mediators on panel for mediation of cases

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3

'

'

'

'

'

'

'

'

'

'

'

'

The number of families of deceased miners with whom the Company has settled

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

29

'

'

'

'

'

'

'

'

'

'

'

'

'

The number of seriously injured employees with whom the Company has settled

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of serious injuries

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of unresolved personal injury and emotional distress claims

'

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of families of the deceased miners filing class action suits

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount of bond plaintiffs requested to be posted by entity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

500,000

'

'

'

'

'

'

'

'

'

'

'

Number of additional putative class actions

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Period of extension of the stay requested (in months)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'6 months

'

'

'

'

'

'

'

Number of plaintiffs

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

3

1

'

'

'

'

'

'

'

'

Number of years of medical monitoring sought in case

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'30 years

'

'

'

'

'

'

Number of environmental groups

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3

3

3

3

'

'

Number of subsidiaries allegedly discharging pollutants without a permit

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

'

'

'

Number of subsidiaries allegedly violating terms of water discharge permits

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7

2

'

2

'

'

Number of subsidiaries included in lawsuits

'

'

'

'

'

'

'

'

'

'

2

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Damages

'

'

'

'

'

'

'

'

118,500

'

'

'

'

265,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

38,500

320,000

Loss Contingency, Receivable

'

'

'

'

'

'

'

'

'

'

'

'

70,000

70,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loss Contingency Accrual, Period Increase (Decrease)

'

'

'

'

'

'

'

'

'

'

'

'

115,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount of guarantee exposure

'

'

'

'

'

'

'

'

'

150,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Indemnity receivable included in prepaid expenses and other current assets

'

'

'

'

'

'

'

'

118,500

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accrued liability included in accrued expenses and other current liabilities

'

'

'

'

'

'

'

'

118,500

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gain (loss) on contract-related matters

'

'

'

'

55,454

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Compensatory and Punitive Damages Awarded

'

'

50,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Compensatory Damages Sought by Plaintiff

'

$44,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Commitments_and_Contingencies_1

Commitments and Contingencies (Details 2) (Senior Secured Revolving Credit Facility [Member], USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Senior Secured Revolving Credit Facility [Member]	'
Statement	'
Letters of Credit Outstanding, Amount	$150,621

Segment_Information_Details

Segment Information (Details)	9 Months Ended
	Sep. 30, 2013
	segments
Segment Reporting [Abstract]	'
Number of reportable segments	2
Western Coal Operations	'
Segment Information	'
Number of surface mines	2
Eastern Coal Operations	'
Segment Information	'
Number of surface mines	24
Number of underground mines	60

Segment_Information_Details_2

Segment Information (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Information	'	'	'	'
Total revenues	$1,191,094	$1,633,809	$3,859,808	$5,416,531
Depreciation, depletion and amortization	196,292	238,894	650,021	797,516
Amortization of acquired intangibles, net	2,748	-11,682	908	-64,480
EBITDA	-341,113	143,901	-233,349	-2,017,733
Capital expenditures	56,123	87,348	163,129	332,592
Acquisition of mineral rights under federal lease	'	17,393	0	53,501
Eastern Coal Operations	'	'	'	'
Segment Information	'	'	'	'
Total revenues	1,050,495	1,446,374	3,451,903	4,899,430
Depreciation, depletion and amortization	175,767	215,961	586,486	730,894
Amortization of acquired intangibles, net	3,434	-15,940	2,561	-78,067
EBITDA	-244,689	123,544	-73,936	-1,978,561
Capital expenditures	54,725	80,695	156,934	304,010
Acquisition of mineral rights under federal lease	'	0	'	0
Western Coal Operations	'	'	'	'
Segment Information	'	'	'	'
Total revenues	128,151	171,982	369,377	459,320
Depreciation, depletion and amortization	13,686	16,868	40,863	47,284
Amortization of acquired intangibles, net	-690	3,480	-1,666	10,472
EBITDA	30,478	42,305	74,276	25,616
Capital expenditures	1,047	4,150	4,149	16,927
Acquisition of mineral rights under federal lease	'	17,393	'	53,501
All Other Segments [Member]	'	'	'	'
Segment Information	'	'	'	'
Total revenues	12,448	15,453	38,528	57,781
Depreciation, depletion and amortization	6,839	6,065	22,672	19,338
Amortization of acquired intangibles, net	4	778	13	3,115
EBITDA	-126,902	-21,948	-233,689	-64,788
Capital expenditures	351	2,503	2,046	11,655
Acquisition of mineral rights under federal lease	'	$0	'	$0

Segment_Information_Details_3

Segment Information (Details 3) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting [Abstract]	'	'	'	'
EBITDA	($341,113)	$143,901	($233,349)	($2,017,733)
Interest expense	-62,233	-47,345	-182,587	-139,313
Interest income	1,008	1,328	3,133	3,749
Income tax (expense) benefit	143,137	83,182	309,022	576,765
Depreciation, depletion and amortization	-196,292	-238,894	-650,021	-797,516
Amortization of acquired intangibles, net	-2,748	11,682	-908	64,480
Net income (loss)	($458,241)	($46,146)	($754,710)	($2,309,568)

Segment_Information_Details_4

Segment Information (Details 4) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Total assets and goodwill	'	'	'	'	'	'
Total assets	$12,097,005	'	$12,097,005	'	$13,089,806	'
Goodwill, net	308,651	'	308,651	'	567,665	2,281,191
Export coal revenues	517,872	639,977	1,716,565	2,296,369	'	'
Export coal revenues as a percentage of aggregate revenue	43.00%	39.00%	44.00%	42.00%	'	'
Eastern Coal Operations	'	'	'	'	'	'
Total assets and goodwill	'	'	'	'	'	'
Total assets	9,817,222	'	9,817,222	'	10,691,029	'
Goodwill, net	308,651	'	308,651	'	561,753	2,221,971
Western Coal Operations	'	'	'	'	'	'
Total assets and goodwill	'	'	'	'	'	'
Total assets	609,905	'	609,905	'	647,292	'
Goodwill, net	0	'	0	'	0	53,308
All Other Segments [Member]	'	'	'	'	'	'
Total assets and goodwill	'	'	'	'	'	'
Total assets	1,669,878	'	1,669,878	'	1,751,485	'
Goodwill, net	$0	'	$0	'	$5,912	$5,912

Supplemental_Guarantor_and_Non1

Supplemental Guarantor and Non-Guarantor Financial Information (Details) (Convertible Debt [Member], anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain])	Sep. 30, 2013
Convertible Debt [Member] | anr_ThreePointSevenFivePercentConvertibleSeniorNotesDueTwentySeventeenMember [Domain]	'
Debt Instrument, Interest Rate, Stated Percentage	3.75%