Alpha Metallurgical Resources (AMR) 10-Q 14 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 31, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	Contura Energy, Inc.
Entity Central Index Key	0001704715
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		18,214,094

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Coal revenues	$ 523,987	$ 443,005	$ 1,784,775	$ 1,446,538
Other revenues	1,877	4,866	6,409	12,583
Total revenues	525,864	447,871	1,791,184	1,459,121
Costs and expenses:
Cost of coal sales (exclusive of items shown separately below)	467,658	397,241	1,480,098	1,199,289
Depreciation, depletion and amortization	60,842	11,141	184,927	33,951
Accretion on asset retirement obligations	6,846	1,489	19,925	5,545
Amortization of acquired intangibles, net	2,314	1,158	(4,712)	12,468
Asset impairment	32	0	5,858	0
Selling, general and administrative expenses (exclusive of depreciation, depletion and amortization shown separately above)	17,387	12,382	53,121	43,490
Merger related costs	68	1,181	1,055	5,064
Total other operating (income) loss:
Mark-to-market adjustment for acquisition-related obligations	(3,238)	0	(288)	0
Other expenses (income)	166	(569)	(7,319)	(17,075)
Total costs and expenses	552,075	424,023	1,732,665	1,282,732
(Loss) income from operations	(26,211)	23,848	58,519	176,389
Other income (expense):
Interest expense	(18,847)	(8,554)	(50,079)	(26,538)
Interest income	1,763	507	5,584	829
Loss on modification and extinguishment of debt	0	0	(26,459)	0
Equity loss in affiliates	(1,845)	(1,624)	(4,804)	(2,857)
Miscellaneous loss, net	(1,523)	(154)	(2,912)	(737)
Total other expense, net	(20,452)	(9,825)	(78,670)	(29,303)
(Loss) income from continuing operations before income taxes	(46,663)	14,023	(20,151)	147,086
Income tax benefit (expense)	3,102	(12)	8,880	(133)
Net (loss) income from continuing operations	(43,561)	14,011	(11,271)	146,953
Discontinued operations:
Loss from discontinued operations before income taxes	(11,516)	(2,117)	(176,973)	(4,330)
Income tax (expense) benefit from discontinued operations	(13,455)	0	12,866	0
Loss from discontinued operations	(24,971)	(2,117)	(164,107)	(4,330)
Net (loss) income	$ (68,532)	$ 11,894	$ (175,378)	$ 142,623
Basic (loss) income per common share:
(Loss) income from continuing operations (in dollars per share)	$ (2.29)	$ 1.45	$ (0.59)	$ 15.30
Loss from discontinued operations (in dollars per share)	(1.31)	(0.22)	(8.63)	(0.45)
Net (loss) income (in dollars per share)	(3.60)	1.23	(9.22)	14.85
Diluted (loss) income per common share:
(Loss) income from continuing operations (in dollars per share)	(2.29)	1.35	(0.59)	14.23
Loss from discontinuing operations (in dollars per share)	(1.31)	(0.20)	(8.63)	(0.42)
Net (loss) income (in dollars per share)	$ (3.60)	$ 1.15	$ (9.22)	$ 13.81
Weighted average shares - basic (in shares)	19,025,462	9,633,164	19,014,974	9,602,860
Weighted average shares - diluted (in shares)	19,025,462	10,384,513	19,014,974	10,328,031

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Other Comprehensive Income [Abstract]
Net (loss) income	$ (68,532)	$ 11,894	$ (175,378)	$ 142,623
Employee benefit plans:
Amortization of and adjustments to employee benefit costs	(86)	39	1,340	(11)
Income tax expense	22	0	(350)	0
Total other comprehensive (loss) income, net of tax	(64)	39	990	(11)
Total comprehensive (loss) income	$ (68,596)	$ 11,933	$ (174,388)	$ 142,612

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 152,638	$ 233,599
Trade accounts receivable, net of allowance for doubtful accounts of $0 as of September 30, 2019 and December 31, 2018	259,931	292,617
Inventories, net	172,591	121,965
Prepaid expenses and other current assets	181,903	158,945
Current assets - discontinued operations	3,401	22,475
Total current assets	770,464	829,601
Property, plant, and equipment, net of accumulated depreciation and amortization of $274,704 and $106,766 as of September 30, 2019 and December 31, 2018	614,624	699,990
Owned and leased mineral rights, net of accumulated depletion and amortization of $23,877 and $11,390 as of September 30, 2019 and December 31, 2018	572,620	528,232
Goodwill	124,353	95,624
Other acquired intangibles, net of accumulated amortization of $39,820 and $20,267 as of September 30, 2019 and December 31, 2018	138,725	154,584
Long-term restricted cash	209,041	227,173
Deferred income taxes	50,516	27,179
Other non-current assets	189,545	183,675
Total assets	2,669,888	2,746,058
Current liabilities:
Current portion of long-term debt	28,982	42,743
Acquisition-related obligations - current	33,165	27,334
Trade accounts payable	98,607	114,568
Accrued expenses and other current liabilities	148,984	148,699
Current liabilities - discontinued operations	20,439	21,892
Total current liabilities	330,177	355,236
Long-term debt	563,846	545,269
Acquisition-related obligations - long-term	51,853	72,996
Workers’ compensation and black lung obligations	260,070	249,294
Pension obligations	176,389	180,802
Asset retirement obligations	223,156	203,694
Deferred income taxes	8,300	15,118
Other non-current liabilities	35,161	52,415
Non-current liabilities - discontinued operations	151,998	94
Total liabilities	1,800,950	1,674,918
Commitments and Contingencies (Note 18)
Stockholders’ Equity
Preferred stock - par value $0.01, 5.0 million shares authorized, none issued	0	0
Common stock - par value $0.01, 50.0 million shares authorized, 20.5 million issued and 18.2 million outstanding at September 30, 2019 and 20.2 million issued and 19.1 million outstanding at December 31, 2018	205	202
Additional paid-in capital	770,822	761,301
Accumulated other comprehensive loss	(22,140)	(23,130)
Treasury stock, at cost: 2.3 million shares at September 30, 2019 and 1.1 million shares at December 31, 2018	(107,700)	(70,362)
Retained earnings	227,751	403,129
Total stockholders’ equity	868,938	1,071,140
Total liabilities and stockholders’ equity	$ 2,669,888	$ 2,746,058

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - Parenthetical - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 0	$ 0
Property, plant and equipment, accumulated amortization, depreciation and amortization	274,704	106,766
Owned and lease mineral rights, accumulated depletion and amortization	23,877	11,390
Other acquired intangibles, accumulated amortization	$ 39,820	$ 20,267
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	20,500,000	20,200,000
Common stock, shares outstanding (in shares)	18,200,000	19,100,000
Treasury stock, shares at cost (in shares)	2,300,000	1,100,000

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities:
Net (loss) income	$ (175,378)	$ 142,623
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, depletion and amortization	330,840	33,951
Amortization of acquired intangibles, net	(4,712)	12,468
Accretion of acquisition-related obligations discount	4,367	4,165
Amortization of debt issuance costs and accretion of debt discount	10,446	2,264
Mark-to-market adjustment for acquisition-related obligations	(288)	0
Loss (gain) on disposal of assets	1,462	(17,103)
Gain on assets acquired in an exchange transaction	(9,083)	0
Loss on modification and extinguishment of debt	26,459	0
Asset impairment	23,020	0
Accretion on asset retirement obligations	24,906	5,545
Employee benefit plans, net	14,513	6,551
Deferred income taxes	(22,021)	0
Stock-based compensation	7,512	9,472
Equity loss in affiliates	4,804	2,857
Other, net	351	610
Changes in operating assets and liabilities	(99,620)	(27,087)
Net cash provided by operating activities	137,578	176,316
Investing activities:
Capital expenditures	(144,183)	(56,722)
Payments on disposal of assets	0	(10,250)
Proceeds on disposal of assets	1,170	647
Purchases of investment securities	(65,193)	0
Maturity of investment securities	50,775	0
Capital contributions to equity affiliates	(7,600)	(3,759)
Other, net	(2,548)	(1,455)
Net cash used in investing activities	(167,579)	(71,539)
Financing activities:
Proceeds from borrowings on debt	544,946	0
Principal repayments of debt	(551,405)	(6,323)
Principal repayments of notes payable	(14,054)	(3,094)
Principal repayments of financing lease obligations	(2,960)	(221)
Debt issuance costs	(6,104)	(466)
Common stock repurchases and related expenses	(35,485)	(4,839)
Other, net	952	70
Net cash used in financing activities	(64,110)	(14,873)
Net (decrease) increase in cash and cash equivalents and restricted cash	(94,111)	89,904
Cash and cash equivalents and restricted cash at beginning of period	477,246	193,960
Cash and cash equivalents and restricted cash at end of period	383,135	283,864
Reconciliation of Cash and Cash Equivalents and Restricted Cash
Total cash and cash equivalents and restricted cash shown in the Condensed Consolidated Statements of Cash Flows	$ 477,246	$ 193,960

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Treasury Stock at Cost	Retained Earnings
Beginning balance at Dec. 31, 2017	$ 92,648	$ 108	$ 40,616	$ (1,948)	$ (50,092)	$ 103,964
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	56,941					56,941
Other comprehensive (loss) income, net	37			37
Stock-based compensation and net issuance of common stock for share vesting	4,479		4,479
Common stock repurchases and related expenses	(4,835)				(4,835)
Ending balance at Mar. 31, 2018	149,270	108	45,095	(1,911)	(54,927)	160,905
Beginning balance at Dec. 31, 2017	92,648	108	40,616	(1,948)	(50,092)	103,964
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	142,623
Other comprehensive (loss) income, net	(11)
Ending balance at Sep. 30, 2018	239,212	108	49,407	(1,959)	(54,931)	246,587
Beginning balance at Mar. 31, 2018	149,270	108	45,095	(1,911)	(54,927)	160,905
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	73,788					73,788
Other comprehensive (loss) income, net	(87)			(87)
Stock-based compensation and net issuance of common stock for share vesting	2,114		2,114
Exercise of stock options	62		62
Warrant exercises	(1)		2		(3)
Ending balance at Jun. 30, 2018	225,146	108	47,273	(1,998)	(54,930)	234,693
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	11,894					11,894
Other comprehensive (loss) income, net	39			39
Stock-based compensation and net issuance of common stock for share vesting	2,127		2,127
Warrant exercises	6		7		(1)
Ending balance at Sep. 30, 2018	239,212	108	49,407	(1,959)	(54,931)	246,587
Beginning balance at Dec. 31, 2018	1,071,140	202	761,301	(23,130)	(70,362)	403,129
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	6,815					6,815
Other comprehensive (loss) income, net	177			177
Stock-based compensation and net issuance of common stock for share vesting	6,377		6,377
Exercise of stock options	306	1	305
Common stock repurchases and related expenses	(4,171)				(4,171)
Ending balance at Mar. 31, 2019	1,080,644	203	767,983	(22,953)	(74,533)	409,944
Beginning balance at Dec. 31, 2018	1,071,140	202	761,301	(23,130)	(70,362)	403,129
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(175,378)
Other comprehensive (loss) income, net	990
Ending balance at Sep. 30, 2019	868,938	205	770,822	(22,140)	(107,700)	227,751
Beginning balance at Mar. 31, 2019	1,080,644	203	767,983	(22,953)	(74,533)	409,944
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(113,661)					(113,661)
Other comprehensive (loss) income, net	877			877
Stock-based compensation and net issuance of common stock for share vesting	(545)		(545)
Exercise of stock options	590	1	589
Warrant exercises	19		19		0
Common stock repurchases and related expenses	(703)				(703)
Ending balance at Jun. 30, 2019	967,221	$ 204	768,046	(22,076)	(75,236)	296,283
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(68,532)					(68,532)
Other comprehensive (loss) income, net	(64)			(64)
Stock-based compensation and net issuance of common stock for share vesting (in shares)		1
Stock-based compensation and net issuance of common stock for share vesting	2,739		2,738
Exercise of stock options	38		38
Common stock repurchases and related expenses	(32,464)				(32,464)
Ending balance at Sep. 30, 2019	$ 868,938	$ 205	$ 770,822	$ (22,140)	$ (107,700)	$ 227,751

Business and Basis of Presentat

Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Basis of Presentation	Business and Basis of Presentation Basis of Presentation Together, the condensed consolidated statements of operations, comprehensive (loss) income, balance sheet, cash flows and stockholders’ equity for the Company are referred to as the “Condensed Consolidated Financial Statements.” The Condensed Consolidated Financial Statements are also referenced across periods as “Condensed Consolidated Balance Sheets,” “Condensed Consolidated Statements of Operations,” and “Condensed Consolidated Statements of Cash Flows.” The Condensed Consolidated Financial Statements include all wholly-owned subsidiaries’ results of operations for the three and nine months ended September 30, 2019 and 2018 . All significant intercompany transactions have been eliminated in consolidation. The accompanying interim Condensed Consolidated Financial Statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) and 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 the financial statements prepared in accordance with U.S. GAAP 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, 2019 are not necessarily indicative of the results to be expected for the year ending December 31, 2019 or any other period. These interim Condensed Consolidated Financial Statements should be read in conjunction with the Company’s Consolidated Financial Statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018. Reclassifications Accretion on asset retirement obligations has been reclassified in the prior year from cost of coal sales to a separate line item in the Condensed Consolidated Statements of Operations to conform to the current year presentation. Freight and handling costs has been reclassified in the prior year from a separate line item into cost of coal sales in the Condensed Consolidated Statements of Operations to conform to the current year presentation. Summary of Significant Accounting Policies Unrestricted and Restricted Investments: Amounts primarily consist of money market funds, other cash equivalents, certificates of deposit, corporate debt securities and U.S. treasury and agency securities classified as either trading securities or held-to-maturity securities. The trading securities are recorded initially at cost and adjusted to fair value at each reporting period. The trading securities’ unrealized gains and losses resulting from fair value adjustments are recorded in current period earnings or loss. The held-to-maturity securities are recorded at amortized cost with interest income recorded in current period earnings. Trading securities of $25,081 (unrestricted investments) and $2,275 (restricted investments) are recorded within Prepaid expenses and other current assets and Other non-current assets on the Company’s Condensed Consolidated Balance Sheets, respectively, as of September 30, 2019. Held-to-maturity securities of $16,374 and $29,137 (restricted investments) are recorded within Other non-current assets on the Company’s Condensed Consolidated Balance Sheets as of September 30, 2019 and December 31, 2018, respectively. New Accounting Pronouncements Leases: I n February 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2016-02 , Leases (“ASU 2016-02”) . ASU 2016-02, along with related amendments issued from 2017 to 2019 (collectively, the “New Leases Standard”), requires a lessee to recognize a right-of-use asset and a lease liability on the balance sheet. The Company adopted ASU 2016-02 effective January 1, 2019 and elected the option to not restate comparative periods in transition and also elected the hindsight practical expedient, which allows the Company to use hindsight when considering lessee options to extend or terminate leases when determining the lease term of lease arrangements for classification purposes, and the package of practical expedients for all leases within the standard, which permits the Company not to reassess its prior conclusions about lease identification, lease classification and initial direct costs. Additionally, the Company elected the transition practical expedient to continue to account for existing and expired land easements at transition as executory contracts. Only land easements entered into or modified after the effective date of Accounting Standards Codification (“ASC”) 842 are accounted for as leases by the Company. As a result of the adoption, the Company recorded operating lease right-of-use assets and lease liabilities on our Condensed Consolidated Balance Sheet. The following table summarizes the impact of the adoption of ASC 842 to the Company’s Condensed Consolidated Balance Sheet: Balance at December 31, 2018 (1) Adjustments Balance at January 1, 2019 Assets Balance Sheet Classification Operating lease right-of-use assets Other non-current assets $ — $ 11,845 $ 11,845 Financing lease assets Property, plant, and equipment, net 9,786 — 9,786 Total lease assets $ 9,786 $ 11,845 $ 21,631 Liabilities Balance Sheet Classification Operating lease liabilities - current Accrued expenses and other current liabilities $ — $ 3,624 $ 3,624 Financing lease liabilities - current Current portion of long-term debt 2,110 — 2,110 Operating lease liabilities - long-term Other non-current liabilities — 8,221 8,221 Financing lease liabilities - long-term Long-term debt 4,313 — 4,313 Total lease liabilities $ 6,423 $ 11,845 $ 18,268 (1) Balances do not include measurement-period adjustments recorded during the nine months ended September 30, 2019 . Refer to Note 2 for further details on measurement-period adjustments recorded during the period. The adoption of ASC 842 did not have an impact on our Condensed Consolidated Statements of Operations, Condensed Consolidated Statements of Comprehensive (Loss) Income, or Condensed Consolidated Statements of Cash Flows. Refer to Note 9 for further disclosure requirements under the new standard. Credit Losses: In June 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Credit Losses (“ASU 2016-13”). ASU 2016-13, along with related amendments and improvements issued in 2018 and 2019, replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable supportable information to inform credit loss estimates. Management anticipates adopting the standard in the first quarter of 2020, although a significant impact to the Company’s financial results is not expected. Stock Compensation : In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting (“ASU 2018-07”). The amendments in this update expand the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. The Company adopted ASU 2018-07 during the first quarter of 2019. The adoption of this ASU did not have a material impact on the Company's Condensed Consolidated Financial Statements and related disclosures.

Mergers and Acquisitions

Mergers and Acquisitions	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Mergers and Acquisitions	Mergers and Acquisitions A Merger with ANR, Inc. (“ANR”) and Alpha Natural Resources Holdings, Inc. (“Holdings”, and, together with ANR, the "Alpha Companies”) was completed on November 9, 2018 (the “Merger” or the “Alpha Merger”). Allocation of Purchase Price The finalized purchase price of $688,534 has been allocated to the net tangible and intangible assets of Alpha Companies as follows: Provisional as of December 31, 2018 Adjustments Final Cash and cash equivalents $ 29,939 $ — $ 29,939 Trade and other receivables 60,714 — 60,714 Inventories 85,635 — 85,635 Short-term restricted cash 10,592 — 10,592 Other current assets 38,495 10,087 48,582 Property, plant, and equipment 504,852 (33,930 ) 470,922 Owned and leased mineral rights 516,201 23,571 539,772 Other intangible assets 154,041 4,363 158,404 Long-term restricted cash 182,049 — 182,049 Long-term restricted investments 28,809 — 28,809 Other non-current assets 68,022 (3,353 ) 64,669 Total assets $ 1,679,349 $ 738 $ 1,680,087 Accounts payable $ 69,049 $ (2,504 ) $ 66,545 Accrued expenses and other current liabilities 76,774 2,491 79,265 Long-term debt, including current portion 144,832 3,626 148,458 Acquisition related obligations 74,346 5,738 80,084 Pension obligations 158,005 3,596 161,601 Asset retirement obligation, including current portion 163,636 12,718 176,354 Deferred income taxes, including current portion 134,924 (8,484 ) 126,440 Other intangible liabilities 57,219 — 57,219 Other non-current liabilities 207,654 12,286 219,940 Total liabilities $ 1,086,439 $ 29,467 $ 1,115,906 Goodwill $ 95,624 $ 28,729 $ 124,353 Allocation of purchase price $ 688,534 $ — $ 688,534 Prior to the finalization of the purchase price allocation, during the nine months ended September 30, 2019 , the Company recorded measurement-period adjustments to the provisional opening balance sheet as shown in the table above. Adjustments were made primarily to property, plant and equipment, owned and leased mineral rights, asset retirement obligations and certain actuarial liabilities. There were no material measurement-period adjustments impacting current-period earnings that would have been recorded in the previous reporting period if the adjustments to the provisional amounts had been recognized as of the acquisition date. In connection with the Merger, the Company originally recorded provisional goodwill of $95,624 , which represents the excess of the purchase price over the estimated fair value of tangible and intangible assets acquired, net of liabilities assumed. As a result of measurement-period adjustments recorded during the nine months ended September 30, 2019 , the provisional amount of goodwill increased by $28,729 resulting in final goodwill of $124,353 as of September 30, 2019 which has been allocated to the Company’s CAPP-Met reportable segment. The goodwill is attributed primarily to the following factors: (i) anticipated operating and administrative synergies, and (ii) deferred income taxes arising from the differences between the preliminary purchase price allocated to the assets and liabilities acquired based on fair value and the tax basis of these assets and liabilities. The goodwill is not deductible for tax purposes. The following table represents the intangible assets and the weighted-average amortization periods as of the acquisition date: Final Weighted-Average Amortization Period In Years ) Mining permits $ 157,555 12.30 Above-market coal supply agreements 849 1.03 Below-market coal supply agreements (57,219 ) 2.10 Total acquired intangibles $ 101,185 10.16 The Condensed Consolidated Statements of Operations include acquisition related expenses (on a pre-tax basis) of $68 and $1,181 in Merger related costs for the three months ended September 30, 2019 and 2018, respectively. The Condensed Consolidated Statements of Operations include acquisition related expenses (on a pre-tax basis) of $1,055 and $5,064 in Merger related costs for the nine months ended September 30, 2019 and 2018, respectively. Acquisition related expenses include professional fees related to legal, tax, advisory integration services and contract related matters. The following unaudited pro forma information has been prepared for illustrative purposes only and assumes the Merger occurred on January 1, 2017. The unaudited pro forma results have been prepared based on estimates and assumptions, which the Company believes are reasonable; however, they are not necessarily indicative of the consolidated results of operations had the Merger occurred on January 1, 2017, or of future results of operations. Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 As reported Pro forma As reported Pro forma Total revenues $ 447,871 $ 633,656 $ 1,459,121 $ 1,972,610 Income from continuing operations $ 14,011 $ 2,801 $ 146,953 $ 182,533 Basic income per common share: Income from continuing operations $ 1.45 $ 0.15 $ 15.30 $ 9.62 Diluted income per common share: Income from continuing operations $ 1.35 $ 0.14 $ 14.23 $ 9.26 Weighted average shares - basic 9,633,164 19,011,363 9,602,860 18,981,059 Weighted average shares - diluted 10,384,513 19,762,712 10,328,031 19,706,230 These amounts have been calculated after applying the Company's accounting policies and adjusting the results of ANR to reflect the additional depreciation, amortization, depletion, and cost of coal sales that would have been charged assuming the fair value adjustments to property, plant and equipment, as well as intangibles, asset retirement obligations, and inventory had been applied at January 1, 2017, together with the consequential tax effects. The pro forma results for the three and nine months ended September 30, 2018 include $1,181 and $5,064 , respectively, of merger-related costs primarily related to professional service fees.

Discontinued Operations

Discontinued Operations	9 Months Ended
	Sep. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations Discontinued operations consist of on-going activity related to the Company’s former Power River Basin (“PRB”) operations. On December 8, 2017, the Company closed a transaction (“PRB Transaction”) with Blackjewel L.L.C. (“Blackjewel” or the “Buyer”) to sell its Eagle Butte and Belle Ayr mines located in Wyoming. However, during the mine permit transfer period, the Company was required to maintain its existing reclamation bonds and related collateral. As of September 30, 2019, the Company had outstanding surety bonds with a total face amount of $227,410 to secure obligations and commitments related to its former PRB operations. To facilitate permit transfer to the Buyer, during 2018, the Company agreed to backstop a total of $44,800 of Blackjewel’s bonding obligations with respect to the Eagle Butte and Belle Ayr permits by entering into secondary general indemnification agreements and providing letters of credit totaling $18,800 to sureties as collateral for the Company’s indemnification obligations. Blackjewel agreed that, by June 30, 2019, it would enter into additional financial arrangements and cause each surety to release and return each letter of credit and cancel the Company’s general indemnification agreements. Indemnity bonds in the amount of $26,000 were issued by a third-party insurer in favor of the Company to insure Blackjewel’s performance obligations with respect to cancellation of the general indemnification agreements and return of the letters of credit. On July 1, 2019, prior to permit transfer, Blackjewel announced that it and certain affiliated entities had filed voluntary petitions for reorganization under Chapter 11 of the Bankruptcy Code in the U.S. Bankruptcy Court for the Southern District of West Virginia (the “Bankruptcy Court”), which are being jointly administered under the caption In re Blackjewel, L.L.C., Case No. 19-30289 (Bankr. S.D.W. Va.). On July 25, 2019, the Company announced that it would seek to serve as the stalking horse purchaser for certain assets offered for sale through Blackjewel’s bankruptcy proceedings. On August 6, 2019, the Bankruptcy Court verbally approved the Company’s purchase of the Eagle Butte and Belle Ayr mines in Wyoming and the Pax Surface Mine in West Virginia for $33,750 pending resolution of outstanding objections. In connection with the stalking horse agreement, the Company made a purchase deposit of $8,100 . On August 29, 2019, as a result of ongoing objections, the Bankruptcy Court entered an order approving the separate sale of the Pax Surface Mine to the Company for $6,150 (including $5,050 from the purchase deposit). On September 18, 2019, the Company announced that it had entered into an agreement which would allow a third-party to purchase the Eagle Butte and Belle Ayr mines from Blackjewel and assume associated reclamation obligations. Refer to Note 20 Subsequent Events. The major components of net loss from discontinued operations in the Condensed Consolidated Statements of Operations are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Revenues: Total revenues (1) $ 4 $ 139 $ 152 $ 1,254 Costs and expenses: Depreciation, depletion and amortization (2) $ — $ — $ 145,913 $ — Accretion on asset retirement obligations (3) $ 4,981 $ — $ 4,981 $ — Asset impairment (4) $ 694 $ — $ 17,162 $ — Selling, general and administrative expenses $ 4,666 $ 12 $ 4,673 $ 39 Other expenses $ 1,032 $ 1,078 $ 3,964 $ 3,453 Other non-major expense (income) items, net $ 147 $ 1,166 $ 432 $ 2,092 (1) Total revenues for the three and nine months ended September 30, 2019 and 2018 consisted entirely of other revenues. (2) The depreciation, depletion and amortization is related to an increase in the Company’s estimate of its asset retirement obligations with respect to the Eagle Butte and Belle Ayr mines as a result of Blackjewel’s bankruptcy filing. The Company remeasured its asset retirement obligations based on the expectation that the mining permits would not transfer to Blackjewel and Blackjewel would be unable to perform its contractual obligation to reclaim the properties. The increase in the asset retirement obligation was recorded to expense as the Company no longer owned the underlying mining assets. Refer to Note 20 Subsequent Events. (3) The accretion on asset retirement obligations is related to the asset retirement obligation as a result of the Blackjewel’s bankruptcy filing. Refer to the above disclosures for further details. (4) The asset impairment for the three and nine months ended September 30, 2019 is primarily related to the write-off of tax related indemnification receivables from Blackjewel. Refer to the disclosures below for further details. Refer to Note 6 for net loss per share information related to discontinued operations. The major components of asset and liabilities that are classified as discontinued operations in the Condensed Consolidated Balance Sheets are as follows: September 30, 2019 December 31, 2018 Assets: Prepaid expenses and other current assets $ 3,401 $ 22,475 Liabilities: Trade accounts payable, accrued expenses and other current liabilities (1) $ 20,439 $ 21,892 Asset retirement obligations (2) $ 151,902 $ — Other non-current liabilities $ 96 $ 94 (1) The liabilities are primarily comprised of taxes for which the Company is considered to be the primary obligor but for which the Buyer was contractually obligated to pay. During the three and nine months ended September 30, 2019 , the Company recorded an impairment charge for the offsetting indemnification receivable as a result of the Blackjewel bankruptcy filing. (2) Refer to discussion of asset retirement obligations in the table above. The major components of cash flows related to discontinued operations are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Other significant operating non-cash items related to discontinued operations: Depreciation, depletion and amortization $ — $ — $ 145,913 $ — Accretion on asset retirement obligations $ 4,981 $ — $ 4,981 $ —

Revenue

Revenue	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Disaggregation of Revenue from Contracts with Customers The following tables disaggregate the Company’s coal revenues by product category and by market to depict how the nature, amount, timing, and uncertainty of the Company’s coal revenues and cash flows are affected by economic factors: Three Months Ended September 30, 2019 Met Thermal Total Export coal revenues $ 248,628 $ 13,187 $ 261,815 Domestic coal revenues 137,146 125,026 262,172 Total coal revenues $ 385,774 $ 138,213 $ 523,987 Three Months Ended September 30, 2018 Met Thermal Total Export coal revenues $ 371,749 $ 12,848 $ 384,597 Domestic coal revenues 15,292 43,116 58,408 Total coal revenues $ 387,041 $ 55,964 $ 443,005 Nine Months Ended September 30, 2019 Met Thermal Total Export coal revenues $ 928,390 $ 39,569 $ 967,959 Domestic coal revenues 429,457 387,359 816,816 Total coal revenues $ 1,357,847 $ 426,928 $ 1,784,775 Nine Months Ended September 30, 2018 Met Thermal Total Export coal revenues $ 1,239,008 $ 28,634 $ 1,267,642 Domestic coal revenues 38,156 140,740 178,896 Total coal revenues $ 1,277,164 $ 169,374 $ 1,446,538 Performance Obligations The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied as of September 30, 2019 . Remainder of 2019 2020 2021 2022 2023 2024 Total Estimated coal revenues $ 64,916 $ 357,281 $ 196,240 $ 138,444 $ 130,267 $ 46,000 $ 933,148 Contract Balances During the nine months ended September 30, 2019 , the Company paid amounts under certain contracts related to the modification of contract terms. These payments were deferred and allocated to the remaining performance obligations after contract modification. The following table includes the opening and closing balances of contract assets from modifications with contracts with customers, which are included within prepaid expenses and other current assets on the Company’s Condensed Consolidated Balance Sheets: September 30, 2019 December 31, 2018 Contract assets (1) $ 985 $ 950 (1) Amounts primarily relate to payments made upon modification of coal contracts. Of the December 31, 2018 contract asset balance, $240 and $757 was recognized within coal revenues in the Company’s Condensed Consolidated Statements of Operations during the three and nine months ended September 30, 2019 , respectively. During the three and nine months ended September 30, 2018 , there were no contract balances as of December 31, 2017 recognized within the Company’s Condensed Consolidated Statements of Operations.

Accumulated Other Comprehensive

Accumulated Other Comprehensive (Loss) Income	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Accumulated Other Comprehensive (Loss) Income	Accumulated Other Comprehensive (Loss) Income The following tables summarize the changes to accumulated other comprehensive (loss) income during the nine months ended September 30, 2019 and 2018 : Balance January 1, 2019 Other comprehensive income (loss) before reclassifications Amounts reclassified from accumulated other comprehensive (loss) income Balance September 30, 2019 Employee benefit costs $ (23,130 ) $ 458 $ 532 $ (22,140 ) Balance January 1, 2018 Other comprehensive income (loss) before reclassifications Amounts reclassified from accumulated other comprehensive (loss) income Balance September 30, 2018 Employee benefit costs $ (1,948 ) $ (128 ) $ 117 $ (1,959 ) The following table summarizes the amounts reclassified from accumulated other comprehensive (loss) income and the Condensed Consolidated Statements of Operations line items affected by the reclassification during the three and nine months ended September 30, 2019 and 2018 : Details about accumulated other comprehensive (loss) income components Amounts reclassified from accumulated other comprehensive (loss) income Affected line item in the Condensed Consolidated Statements of Operations Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Employee benefit costs: Amortization of actuarial loss $ 258 $ 39 $ 719 $ 117 (1) Miscellaneous loss, net Income tax expense (67 ) — (187 ) — Income tax benefit (expense) Total, net of income tax $ 191 $ 39 $ 532 $ 117 (1) These accumulated other comprehensive (loss) income components are included in the computation of net periodic benefit costs for pension, black lung, life insurance and other employee benefit plans. Refer to Note 16 .

Net (Loss) Income Per Share

Net (Loss) Income Per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Net (Loss) Income Per Share	Net (Loss) Income Per Share The number of shares used to calculate basic net (loss) income per common share is based on the weighted average number of the Company’s outstanding common shares during the respective period. The number of shares used to calculate diluted net (loss) income per common share is based on the number of common shares used to calculate basic net (loss) income per share plus the dilutive effect of stock options and other stock-based instruments held by the Company’s employees and directors during the period, and the Company’s outstanding Series A warrants. The warrants become dilutive for net (loss) income per common share calculations when the market price of the Company’s common stock exceeds the exercise price. For the three months ended September 30, 2018 , there were no anti-dilutive stock options or other stock-based instruments. For the nine months ended September 30, 2018 , 86,347 stock options were excluded from the computation of dilutive net (loss) income per share because they would have been anti-dilutive. These potential shares could dilute net (loss) income per share in the future. In periods of net loss, the number of shares used to calculate diluted earnings per share is the same as basic earnings per share. The following table presents the net (loss) income per common share for the three and nine months ended September 30, 2019 and 2018 : Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Net (loss) income (Loss) income from continuing operations $ (43,561 ) $ 14,011 $ (11,271 ) $ 146,953 Loss from discontinued operations (24,971 ) (2,117 ) (164,107 ) (4,330 ) Net (loss) income $ (68,532 ) $ 11,894 $ (175,378 ) $ 142,623 Basic Weighted average common shares outstanding - basic 19,025,462 9,633,164 19,014,974 9,602,860 Basic (loss) income per common share: (Loss) income from continuing operations $ (2.29 ) $ 1.45 $ (0.59 ) $ 15.30 Loss from discontinued operations (1.31 ) (0.22 ) (8.63 ) (0.45 ) Net (loss) income $ (3.60 ) $ 1.23 $ (9.22 ) $ 14.85 Diluted Weighted average common shares outstanding - basic 19,025,462 9,633,164 19,014,974 9,602,860 Diluted effect of warrants — 304,243 — 270,611 Diluted effect of stock options — 260,653 — 265,794 Diluted effect of restricted share units, restricted stock shares and performance-based restricted share units — 186,453 — 188,766 Weighted average common shares outstanding - diluted 19,025,462 10,384,513 19,014,974 10,328,031 Diluted (loss) income per common share: (Loss) income from continuing operations $ (2.29 ) $ 1.35 $ (0.59 ) $ 14.23 Loss from discontinued operations (1.31 ) (0.20 ) (8.63 ) (0.42 ) Net (loss) income $ (3.60 ) $ 1.15 $ (9.22 ) $ 13.81

Inventories, Net

Inventories, Net	9 Months Ended
	Sep. 30, 2019
Inventory Disclosure [Abstract]
Inventories, Net	Inventories, net Inventories, net consisted of the following: September 30, 2019 December 31, 2018 Raw coal $ 31,924 $ 33,607 Saleable coal 115,290 63,767 Materials, supplies and other, net 25,377 24,591 Total inventories, net $ 172,591 $ 121,965

Goodwill and Acquired Intangibl

Goodwill and Acquired Intangibles	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Acquired Intangibles	Goodwill and Acquired Intangibles Goodwill In connection with the Merger, the Company recorded goodwill. Refer to Note 2 for information on goodwill. The Company performed an interim goodwill impairment test as of August 31, 2019 due to a decline in the Company’s market capitalization to amounts below book value combined with a decline in global metallurgical coal pricing during the period which indicated that the fair value of a CAPP Met segment reporting unit may have been below the carrying value. Following the testing, the Company concluded that the fair value of the reporting unit exceeded the carrying value and no amounts of goodwill were impaired. However, further deterioration or weakness in the global metallurgical coal market, as well as other factors that could result in adverse changes in the key assumptions described in our Annual Report on Form 10-K for the year ended December 31, 2018, could lead to a reduction in the fair value of the reporting unit. Accordingly, the Company’s goodwill may be at risk of impairment. Acquired Intangibles The Company has recognized assets for acquired above market-priced coal supply agreements and acquired mine permits and liabilities for acquired below market-priced coal supply agreements. The coal supply agreements were valued based on the present value of the difference between the expected net contractual cash flows based on the stated contract terms, and the estimated net contractual cash flows derived from applying forward market prices at the Merger or acquisition date for new contracts of similar terms and conditions. The acquired mine permits were valued based on the replacement cost and lost profits method as of the Merger date. The balances and respective balance sheet classifications of such assets and liabilities as of September 30, 2019 and December 31, 2018, net of accumulated amortization, are set forth in the following tables: September 30, 2019 Assets (1) Liabilities (2) Net Total Coal supply agreements, net $ 2,450 $ (8,978 ) $ (6,528 ) Acquired mine permits, net 136,275 — 136,275 Total $ 138,725 $ (8,978 ) $ 129,747 December 31, 2018 Assets (1) Liabilities (2) Net Total Coal supply agreements, net $ 4,687 $ (33,912 ) $ (29,225 ) Acquired mine permits, net 149,897 — 149,897 Total $ 154,584 $ (33,912 ) $ 120,672 (1) Included within other acquired intangibles, net of accumulated amortization on the Company’s Condensed Consolidated Balance Sheets. (2) Included within other non-current liabilities on the Company’s Condensed Consolidated Balance Sheets. The acquired mine permits are amortized over the estimated life of the associated mine. The coal supply agreement assets and liabilities are amortized over the actual number of tons shipped over the life of each contract. Amortization of mine permits acquired as a result of the Merger was $6,266 and $17,871 for the three and nine months ended September 30, 2019 which is reported within amortization of acquired intangibles, net in the Condensed Consolidated Statements of Operations. Amortization of above-market coal supply agreements was $1,473 and $1,158 , and amortization of below-market coal supply agreements was ($5,425) and $0 , resulting in a net (income) expense of ( $3,952 ) and $1,158 for the three months ended September 30, 2019 and 2018, respectively, which is reported within amortization of acquired intangibles, net in the Condensed Consolidated Statements of Operations. Amortization of above-market coal supply agreements was $2,351 and $12,468 , and amortization of below-market coal supply agreements was ( $24,934 ) and $0 , resulting in a net (income) expense of ( $22,583 ) and $12,468 for the nine months ended September 30, 2019 and 2018, respectively, which is reported within amortization of acquired intangibles, net in the Condensed Consolidated Statements of Operations.

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases	Leases Subsequent to the adoption of ASC 842, the Company recognizes right of use assets and lease liabilities on the balance sheet for all leases with a term longer than 12 months. The discount rates used to determine the present value of the lease assets and liabilities are based on the Company’s incremental borrowing rate at the lease commencement date and commensurate with the remaining lease term. As the rates implicit in most of the Company’s leases are not readily determinable, the Company uses a collateralized incremental borrowing rate based on the information available at the lease commencement date in determining the present value of future payments. The Company uses the portfolio approach and group leases by short-term and long-term categories, applying the corresponding incremental borrowing rates to these categories of leases. For leases with a term of 12 months or less, no right of use assets or liabilities are recognized on the balance sheet and the Company recognizes the lease expense on a straight-line basis over the lease term. Additionally, the Company recognizes variable lease payments as an expense in the period incurred. The Company’s lease population consists primarily of vehicle and heavy equipment leases and leases for office equipment. The Company’s building and land leases relate to corporate office space and certain site offices. The Company determines whether a contract contains a lease based on whether the Company obtains the right to control the use of specifically identifiable property, plant, and equipment for a period of time in exchange for consideration. For the nine months ended September 30, 2019 , the Company identified no instances requiring significant judgment in determining whether any contracts entered into during the period were or were not leases. Additionally, the Company had no material sublease agreements within the scope of ASC 842 or lease agreements for which the Company was the lessor for the nine months ended September 30, 2019 . Renewal options in the Company’s lease population primarily relate to month-to-month extensions on vehicle leases and are immaterial both individually and in the aggregate. The Company includes renewal options that are reasonably certain to be exercised in the measurement of lease liabilities. As of September 30, 2019 , the Company does not intend to exercise any termination options on existing leases. As of September 30, 2019 , the Company had the following right-of-use assets and lease liabilities within the Company’s Condensed Consolidated Balance Sheets: September 30, 2019 Assets Balance Sheet Classification Financing lease assets Property, plant, and equipment, net $ 10,779 Operating lease right-of-use assets Other non-current assets 9,325 Total lease assets $ 20,104 Liabilities Balance Sheet Classification Financing lease liabilities - current Current portion of long-term debt $ 3,146 Operating lease liabilities - current Accrued expenses and other current liabilities 2,079 Financing lease liabilities - long-term Long-term debt 5,206 Operating lease liabilities - long-term Other non-current liabilities 7,246 Total lease liabilities $ 17,677 Total lease costs and other lease information for the three and nine months ended September 30, 2019 included the following: Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Lease cost (1) Finance lease cost: Amortization of leased assets $ 1,143 $ 2,796 Interest on lease liabilities 108 366 Operating lease cost 732 2,062 Short-term lease cost 494 1,474 Total lease cost $ 2,477 $ 6,698 (1) The Company had no variable lease costs or sublease income for the nine months ended September 30, 2019 . Nine Months Ended September 30, 2019 Other information Cash paid for amounts included in the measurement of lease liabilities $ 6,862 Operating cash flows from finance leases $ 366 Operating cash flows from operating leases $ 3,536 Financing cash flows from finance leases $ 2,960 Right-of-use assets obtained in exchange for new finance lease liabilities $ 1,142 Lease Term and Discount Rate Weighted-average remaining lease term in months - finance leases 32.8 Weighted-average remaining lease term in months - operating leases 94.6 Weighted-average discount rate - finance leases 5.2 % Weighted-average discount rate - operating leases 10.9 % The Company has elected to show net instead of gross amounts for right-of-use assets and liabilities within its Condensed Consolidated Statements of Cash Flows. The following table summarizes the maturity of the Company’s lease liabilities on an undiscounted cash flow basis and a reconciliation to the lease liabilities recognized in the Company’s Condensed Consolidated Balance Sheet as of September 30, 2019 : Finance Leases Operating Leases Lease cost Remainder of 2019 $ 884 $ 785 2020 3,500 2,580 2021 2,864 1,961 2022 1,607 1,654 2023 97 1,193 Thereafter — 6,283 Total future minimum lease payments $ 8,952 $ 14,456 Imputed interest (600 ) (5,131 ) Present value of future minimum lease payments $ 8,352 $ 9,325 As of September 30, 2019 , the Company had no leases with future commencement dates that will create significant rights or obligations for the Company.
Leases	Leases Subsequent to the adoption of ASC 842, the Company recognizes right of use assets and lease liabilities on the balance sheet for all leases with a term longer than 12 months. The discount rates used to determine the present value of the lease assets and liabilities are based on the Company’s incremental borrowing rate at the lease commencement date and commensurate with the remaining lease term. As the rates implicit in most of the Company’s leases are not readily determinable, the Company uses a collateralized incremental borrowing rate based on the information available at the lease commencement date in determining the present value of future payments. The Company uses the portfolio approach and group leases by short-term and long-term categories, applying the corresponding incremental borrowing rates to these categories of leases. For leases with a term of 12 months or less, no right of use assets or liabilities are recognized on the balance sheet and the Company recognizes the lease expense on a straight-line basis over the lease term. Additionally, the Company recognizes variable lease payments as an expense in the period incurred. The Company’s lease population consists primarily of vehicle and heavy equipment leases and leases for office equipment. The Company’s building and land leases relate to corporate office space and certain site offices. The Company determines whether a contract contains a lease based on whether the Company obtains the right to control the use of specifically identifiable property, plant, and equipment for a period of time in exchange for consideration. For the nine months ended September 30, 2019 , the Company identified no instances requiring significant judgment in determining whether any contracts entered into during the period were or were not leases. Additionally, the Company had no material sublease agreements within the scope of ASC 842 or lease agreements for which the Company was the lessor for the nine months ended September 30, 2019 . Renewal options in the Company’s lease population primarily relate to month-to-month extensions on vehicle leases and are immaterial both individually and in the aggregate. The Company includes renewal options that are reasonably certain to be exercised in the measurement of lease liabilities. As of September 30, 2019 , the Company does not intend to exercise any termination options on existing leases. As of September 30, 2019 , the Company had the following right-of-use assets and lease liabilities within the Company’s Condensed Consolidated Balance Sheets: September 30, 2019 Assets Balance Sheet Classification Financing lease assets Property, plant, and equipment, net $ 10,779 Operating lease right-of-use assets Other non-current assets 9,325 Total lease assets $ 20,104 Liabilities Balance Sheet Classification Financing lease liabilities - current Current portion of long-term debt $ 3,146 Operating lease liabilities - current Accrued expenses and other current liabilities 2,079 Financing lease liabilities - long-term Long-term debt 5,206 Operating lease liabilities - long-term Other non-current liabilities 7,246 Total lease liabilities $ 17,677 Total lease costs and other lease information for the three and nine months ended September 30, 2019 included the following: Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Lease cost (1) Finance lease cost: Amortization of leased assets $ 1,143 $ 2,796 Interest on lease liabilities 108 366 Operating lease cost 732 2,062 Short-term lease cost 494 1,474 Total lease cost $ 2,477 $ 6,698 (1) The Company had no variable lease costs or sublease income for the nine months ended September 30, 2019 . Nine Months Ended September 30, 2019 Other information Cash paid for amounts included in the measurement of lease liabilities $ 6,862 Operating cash flows from finance leases $ 366 Operating cash flows from operating leases $ 3,536 Financing cash flows from finance leases $ 2,960 Right-of-use assets obtained in exchange for new finance lease liabilities $ 1,142 Lease Term and Discount Rate Weighted-average remaining lease term in months - finance leases 32.8 Weighted-average remaining lease term in months - operating leases 94.6 Weighted-average discount rate - finance leases 5.2 % Weighted-average discount rate - operating leases 10.9 % The Company has elected to show net instead of gross amounts for right-of-use assets and liabilities within its Condensed Consolidated Statements of Cash Flows. The following table summarizes the maturity of the Company’s lease liabilities on an undiscounted cash flow basis and a reconciliation to the lease liabilities recognized in the Company’s Condensed Consolidated Balance Sheet as of September 30, 2019 : Finance Leases Operating Leases Lease cost Remainder of 2019 $ 884 $ 785 2020 3,500 2,580 2021 2,864 1,961 2022 1,607 1,654 2023 97 1,193 Thereafter — 6,283 Total future minimum lease payments $ 8,952 $ 14,456 Imputed interest (600 ) (5,131 ) Present value of future minimum lease payments $ 8,352 $ 9,325 As of September 30, 2019 , the Company had no leases with future commencement dates that will create significant rights or obligations for the Company.

Stock Repurchases

Stock Repurchases	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Stock Repurchases	Stock Repurchases During the three months ended June 30, 2019, the Company’s Board of Directors adopted a capital return program that permits the Company to return to stockholders up to an aggregate amount of $250,000 of capital. The capital return program does not have a fixed expiration date, and returns of capital may take the form of share repurchases, dividends or a combination thereof. Any share repurchases may be made from time to time through open market transactions, block trades, privately negotiated transactions, tender offers, or otherwise. Any returns of capital under the program will be at the discretion of the Company’s Board of Directors and are subject to market and business conditions, levels of available liquidity, the Company’s cash needs, restrictions under agreements or obligations, legal or regulatory requirements or restrictions, and other relevant factors. On August 29, 2019, the Company announced that its Board of Directors had approved a stock repurchase plan (the “Company Repurchase Plan”) to acquire up to $100,000 in the aggregate of the Company’s common stock at prices as set forth in such plan over a specified period, in accordance with the guidelines specified in Rule 10b-18 and Rule 10b5-1 of the Securities Exchange Act of 1934. As of September 30, 2019 , the Company had repurchased an aggregate of 529,303 shares of common stock under the Company Repurchase Plan for an aggregate purchase price of $15,969 (comprised of $15,953 of share repurchases and $16 of related fees) for an average price paid for share of $30.17 . As of October 1, 2019, the Company suspended the Company Repurchase Plan. Additionally, on September 12, 2019, the Company entered into a common stock repurchase agreement with Whitebox Multi-Strategy Partners, L.P., Whitebox Asymmetric Partners, L.P., Whitebox Credit Partners, L.P. and Whitebox Institutional Partners, L.P. (the “Stockholders”). Pursuant to terms of the common stock repurchase agreement, the Company repurchased an aggregate of 500,000 shares of common stock from the Stockholders at $32.99 per share for an aggregate purchase price of $16,495 .

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt consisted of the following: September 30, 2019 December 31, 2018 Term Loan Credit Facility - due November 2025 $ — $ 550,000 Term Loan Credit Facility - due June 2024 560,395 — LCC Note Payable 45,000 62,500 LCC Water Treatment Obligation 10,625 11,875 Other 9,755 8,395 Debt discount and issuance costs (32,947 ) (44,758 ) Total long-term debt 592,828 588,012 Less current portion (28,982 ) (42,743 ) Long-term debt, net of current portion $ 563,846 $ 545,269 Term Loan Credit Facility - due June 2024 On June 14, 2019, the Company entered into a Credit Agreement with Cantor Fitzgerald Securities, as administrative agent and collateral agent, and the other lenders party thereto (as defined therein) that provides for a senior secured term loan facility in the aggregate principal amount of $561,800 with a maturity date of June 14, 2024 (the “Term Loan Credit Facility”). Principal repayments equal to approximately $1,405 are due each March, June, September and December (commencing with September 30, 2019) with the final principal repayment installment repaid on the maturity date and in an amount equal to the aggregate principal amount outstanding on such date. The Term Loan Credit Facility bears an interest rate per annum based on the character of the loan (defined as either “Base Rate Loan” or “Eurocurrency Rate Loan”) plus an applicable rate of 6.00% for Base Rate Loans and 7.00% for Eurocurrency Rate Loans on or prior to the second anniversary of the Closing Date and 7.00% or 8.00% thereafter (the “Applicable Rate”). Interest accrued on each Base Rate Loan is payable in arrears on the last business day of each March, June, September and December and the maturity date. Interest accrued on each Eurocurrency Rate Loan is payable in arrears on the last day of each interest period as defined therein. As of September 30, 2019 , the borrowings made under the Term Loan Credit Facility were comprised of Eurocurrency Rate Loans with an interest rate of 9.03% , calculated as the eurocurrency rate during the period plus an applicable rate of 7.00% . As of September 30, 2019 , the carrying value of the Term Loan Credit Facility was $538,395 with $5,618 classified as current, within the Condensed Consolidated Balance Sheets. As of December 31, 2018, the carrying value of the term loan credit facility under the Amended and Restated Credit Agreement dated November 9, 2018 was $521,667 with $20,625 classified as current, within the Condensed Consolidated Balance Sheets. The Term Loan Credit Facility was provided primarily by certain of the Company’s existing shareholders (related parties) as of the agreement date. As such, the Company analyzed various factors of the transaction and concluded the Term Loan Credit Facility was issued at a reasonable market rate and therefore considered to be an arm’s length transaction. The Company used the proceeds from the Term Loan Credit Facility to repay the outstanding principal balance of $543,125 under the Amended and Restated Credit Agreement dated November 9, 2018 and fees related to such refinancing. The Company recorded a loss on modification of debt of $255 , primarily related to modification fees paid under the refinance, and a loss on extinguishment of debt of $26,204 , primarily related to the write-off of outstanding debt discounts and unamortized debt issuance costs under the Amended and Restated Credit Agreement dated November 9, 2018, which are recorded in loss on modification and extinguishment of debt within the Condensed Consolidated Statements of Operations. All obligations under the Term Loan Credit Facility are substantially guaranteed by the Company’s existing wholly owned domestic subsidiaries, and are required to be guaranteed by the Company’s future wholly owned domestic subsidiaries. Certain obligations under the Term Loan Facility are secured by a senior lien, subject to certain exceptions (including the ABL Priority Collateral described below), by substantially all of the Company’s assets and the assets of the Company’s subsidiary guarantors (“Term Loan Priority Collateral”), in each case subject to exceptions. The obligations under the Term Loan Credit Facility are also secured by a junior lien, again subject to certain exceptions, against the ABL Priority Collateral. The Term Loan Facility contains negative and affirmative covenants including certain financial covenants that are more flexible than the covenants on the Amended and Restated Credit Agreement dated November 9, 2018. The Company was in compliance with all covenants under this agreement as of September 30, 2019 . Amended and Restated Asset-Based Revolving Credit Agreement As of September 30, 2019 , the Company had no borrowings and $48,634 letters of credit outstanding under the senior secured asset-based revolving credit facility (the “ABL Facility”). The Amended and Restated Asset-Based Revolving Credit Agreement, as amended, and related documents contain negative and affirmative covenants including certain financial covenants. The Company was in compliance with all covenants under these agreements as of September 30, 2019 . LCC Note Payable The Lexington Coal Company (“LCC”) Note Payable has no stated interest rate and an imputed interest rate of 12.45% . The carrying value of the LCC Note Payable was $36,483 and $49,361 , with $17,500 and $17,500 reported within the current portion of long-term debt as of September 30, 2019 and December 31, 2018, respectively. LCC Water Treatment Stipulation The LCC Water Treatment Stipulation has no stated interest rate and an imputed interest rate of 13.12% . The carrying value of the LCC Water Treatment Stipulation was $8,196 and $8,589 , with $2,500 and $1,875 reported within the current portion of long-term debt as of September 30, 2019 and December 31, 2018, respectively. Finance Leases The Company entered into financing leases for certain property and other equipment during 2019 and 2018 . The Company’s liability for financing leases was $8,352 and $6,423 , with $3,146 and $2,110 reported within the current portion of long-term debt as of September 30, 2019 and December 31, 2018 , respectively. Financing leases are included in the other line item in the table above. Refer to Note 9 for additional information on leases.

Acquisition-Related Obligations

Acquisition-Related Obligations	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Acquisition-Related Obligations	Acquisition-Related Obligations Acquisition-related obligations consisted of the following: September 30, 2019 December 31, 2018 Contingent Revenue Obligation $ 55,703 $ 59,880 Environmental Settlement Obligations 16,305 19,306 Reclamation Funding Liability 12,000 22,000 Retiree Committee VEBA Funding Settlement Liability 1,000 3,500 UMWA Funds Settlement Liability 6,000 6,000 Discount (5,990 ) (10,356 ) Total acquisition-related obligations - long-term 85,018 100,330 Less current portion (33,165 ) (27,334 ) Acquisition-related obligations, net of current portion $ 51,853 $ 72,996 Contingent Revenue Obligation As of September 30, 2019 and December 31, 2018 the carrying value of the Contingent Revenue Obligation was $55,703 and $59,880 , with $14,764 and $9,459 classified as current, respectively, classified as an acquisition-related obligation in the Condensed Consolidated Balance Sheets. Refer to Note 14 for further disclosures related to the fair value assignment and methods used. During the second quarter of 2019, the Company paid $9,627 pursuant to terms of the Contingent Revenue Obligation. Environmental Settlement Obligations As of September 30, 2019 and December 31, 2018, the carrying value of the Environmental Settlement Obligations was $13,168 and $14,768 , net of discounts of $3,137 and $4,538 , with $5,124 and $3,375 classified as current, respectively, all of which was classified as an acquisition-related obligation in the Condensed Consolidated Balance Sheets. Reclamation Funding Agreement As of September 30, 2019 and December 31, 2018, the carrying value of the Funding of Restricted Cash Reclamation liability was $10,321 and $18,106 , net of discounts of $1,679 and $3,894 , with $10,321 and $10,000 classified as current, respectively, all of which was classified as an acquisition-related obligation in the Condensed Consolidated Balance Sheets.

Asset Retirement Obligations

Asset Retirement Obligations	9 Months Ended
	Sep. 30, 2019
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, 2019 : Total asset retirement obligations at December 31, 2018 $ 228,448 Measurement-period adjustments (1) 12,718 Accretion for the period 19,911 Sites added during the period 5,113 Revisions in estimated cash flows (43 ) Expenditures for the period (18,626 ) Total asset retirement obligations at September 30, 2019 247,521 Less current portion (24,365 ) Long-term portion $ 223,156 (1) Refer to Note 2 for additional information on the Merger and related measurement-period adjustments recorded during the nine months ended September 30, 2019 . Refer to Note 3 for detail on the $151,902 of asset retirement obligations as September 30, 2019 within discontinued operations due to the Blackjewel Chapter 11 bankruptcy filing. Additionally, refer to Note 20 for further developments within subsequent event disclosures.

Fair Value of Financial Instrum

Fair Value of Financial Instruments and Fair Value Measurements	9 Months Ended
	Sep. 30, 2019
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, short-term and long-term restricted cash, short-term and long-term deposits, trade accounts payable, and accrued expenses and other current liabilities approximate fair value as of September 30, 2019 and December 31, 2018 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, 2019 and December 31, 2018 : September 30, 2019 Carrying Amount (1) Total Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Term Loan Credit Facility - due June 2024 $ 538,395 $ 546,386 $ 546,386 $ — $ — LCC Note Payable 36,483 36,517 — — 36,517 LCC Water Treatment Obligation 8,196 8,284 — — 8,284 Total long-term debt $ 583,074 $ 591,187 $ 546,386 $ — $ 44,801 December 31, 2018 Carrying Amount (1) Total Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Term Loan Credit Facility - due November 2025 $ 521,667 $ 540,375 $ 540,375 $ — $ — LCC Note Payable 49,361 50,606 — — 50,606 LCC Water Treatment Obligation 8,589 8,827 — — 8,827 Total long-term debt $ 579,617 $ 599,808 $ 540,375 $ — $ 59,433 (1) Net of debt discounts and debt issuance costs. The following tables set forth by level, within the fair value hierarchy, the Company’s acquisition-related obligations at fair value as of September 30, 2019 and December 31, 2018 : September 30, 2019 Carrying Amount (1) Total Fair Quoted Prices Significant Other Significant Retiree Committee VEBA Funding $ 956 $ 969 $ — $ — $ 969 UMWA Funds Settlement Liability 4,870 5,134 — — 5,134 Reclamation Funding Liability 10,321 10,814 — — 10,814 Environmental Settlement Obligations 13,168 13,188 — — 13,188 Total acquisition-related obligations $ 29,315 $ 30,105 $ — $ — $ 30,105 December 31, 2018 Carrying Amount (1) Total Fair Quoted Prices Significant Other Significant Retiree Committee VEBA Funding $ 3,337 $ 3,391 $ — $ — $ 3,391 UMWA Funds Settlement Liability 4,239 4,729 — — 4,729 Reclamation Funding Liability 18,106 19,362 — — 19,362 Environmental Settlement Obligations 14,768 14,936 — — 14,936 Total acquisition-related obligations $ 40,450 $ 42,418 $ — $ — $ 42,418 (1) Net of discounts. The following table sets 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 basis as of September 30, 2019 and December 31, 2018 . 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, 2019 Total Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Contingent Revenue Obligation $ 55,703 $ — $ — $ 55,703 Trading securities $ 27,356 $ 1,624 $ 25,732 $ — December 31, 2018 Total Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Contingent Revenue Obligation $ 59,880 $ — $ — $ 59,880 The following table is a reconciliation of the financial and non-financial assets and liabilities that were accounted for at fair value on a recurring basis and that were categorized within Level 3 of the fair value hierarchy: December 31, 2018 Payments Measurement Period Adjustments (1) Loss Recognized in Earnings Transfer In (Out) of Level 3 Fair Value Hierarchy September 30, 2019 Contingent Revenue Obligation $ 59,880 $ (9,627 ) $ 5,738 $ (288 ) $ — $ 55,703 (1) Refer to Note 2 for additional information on the Merger and related measurement-period adjustments recorded during the nine months ended September 30, 2019 . 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 Term Loan Credit Facility - due June 2024 and Term Loan Credit Facility - due November 2025 - The fair value is based on observable market data. Trading Securities - Includes money market funds and other cash equivalents. The fair value is based on observable market data. Level 2 Fair Value Measurements Trading Securities - Includes certificates of deposit, corporate debt securities and U.S. treasury and agency securities. The fair values of the Company’s trading securities are obtained from a third-party pricing service provider. The fair values provided by the pricing service provider 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. Level 3 Fair Value Measurements LCC Note Payable, LCC Water Treatment Obligation, Retiree Committee VEBA Funding Settlement Liability, UMWA Funds Settlement Liability, Environmental Settlement Obligations and Reclamation Funding Liability - Observable transactions are not available to aid in determining the fair value of these items. Therefore, the fair value was derived by using the expected present value approach in which estimated cash flows are discounted using a risk-free interest rate adjusted for market risk. Contingent Revenue Obligation - The fair value of the contingent revenue obligation was estimated using a Black-Scholes pricing model and is marked to market at each reporting period with changes in value reflected in earnings. The inputs included in the Black-Scholes pricing model are the Company's forecasted future revenue, the stated royalty rate, the remaining periods in the obligation; annual risk-free interest rate based on the US Constant Maturity Treasury Curve and annualized volatility. The annualized volatility was calculated by observing volatilities for comparable companies with adjustments for the Company's size and leverage. Acquisition accounting - The Company accounts for business combinations under the acquisition method of accounting. The total cost of acquisitions is allocated to the underlying identifiable net tangible and intangible assets based on their respective estimated fair values. Determining the fair value of assets acquired and liabilities assumed requires management’s judgment, the utilization of independent valuation experts and often involves the use of significant estimates and assumptions with respect to the timing and amounts of future cash inflows and outflows, discount rates, market prices and asset lives, among other items. A combination of income, market and cost approaches are used for the valuation where appropriate, depending on the assets or liabilities being valued. The valuation inputs in these models and analyses give consideration to market participant assumptions.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the nine months ended September 30, 2019 , the Company recorded income tax benefit of $8,880 on a loss from continuing operations before income taxes of $20,151 . The income tax benefit differs from the expected statutory amount primarily due to the permanent impact of percentage depletion deductions and the permanent impact of stock-based compensation deductions, partially offset by an increase in the valuation allowance. As of September 30, 2019, the Company anticipates that no current federal income tax liability will be generated in 2019. For the nine months ended September 30, 2018, the Company recorded income tax expense of $133 on income from continuing operations before income taxes of $147,086 . The income tax expense differs from the expected statutory amount primarily due to the permanent impact of percentage depletion deductions and the reduction in the valuation allowance, partially offset by the impact of state income taxes, net of federal tax impact. During the nine months ended September 30, 2019 , the Company recorded an increase of $31,984 to its deferred tax asset valuation allowance, which consists of a $1,213 increase recorded to continuing operations and a $30,771 increase recorded to discontinued operations. The Company currently is relying primarily on the reversal of taxable temporary differences, along with consideration of taxable income via carryback to prior years and tax planning strategies, to support the realization of deferred tax assets. For each reporting period, the Company updates its assessment regarding the realizability of its deferred tax assets, including scheduling the reversal of its deferred tax assets and liabilities, to determine the amount of valuation allowance needed. Scheduling the reversal of deferred tax asset and liability balances requires judgment and estimation. The Company believes the deferred tax liabilities relied upon as future taxable income in its assessment will reverse in the same period and jurisdiction and are of the same character as the temporary differences giving rise to the deferred tax assets that will be realized. The valuation allowance recorded represents the portion of deferred tax assets for which the Company is unable to support realization through the methods described above.

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2019
Compensation Related Costs [Abstract]
Employee Benefit Plans	Employee Benefit Plans The Company provides several types of benefits for its employees, including postemployment life insurance, defined benefit and defined contribution pension plans, and workers’ compensation and black lung benefits. The Company does not participate in any multi-employer plans. The components of net periodic (benefit) expense other than the service cost component for pension, black lung, and life insurance benefits are included in the line item miscellaneous loss, net in the Condensed Consolidated Statements of Operations. Pension The following table details the components of the net periodic (benefit) expense for pension obligations: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 Interest cost $ 6,636 $ 19,929 Expected return on plan assets (7,011 ) (21,032 ) Amortization of net actuarial loss 199 597 Net periodic benefit $ (176 ) $ (506 ) As the Company assumed these pension obligations in connection with the Merger, there was no net periodic (benefit) expense for the three and nine months ended September 30, 2018 . Black Lung The following table details the components of the net periodic (benefit) expense for black lung obligations: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Service cost $ 751 $ 194 $ 1,558 $ 582 Interest cost 1,567 174 3,386 521 Expected return on plan assets (17 ) — (49 ) — Amortization of net actuarial loss 72 50 162 150 Net periodic expense $ 2,373 $ 418 $ 5,057 $ 1,253 Life Insurance Benefits The following table details the components of the net periodic (benefit) expense for life insurance benefit obligations: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Interest cost $ 106 $ 97 $ 318 $ 291 Amortization of net actuarial gain (26 ) (11 ) (78 ) (33 ) Net periodic expense $ 80 $ 86 $ 240 $ 258 Defined Contribution and Profit Sharing Plans The Company sponsors defined contribution plans to assist its eligible employees in providing for retirement. Generally, under the terms of these plans, employees make voluntary contributions through payroll deductions and the Company makes matching and/or discretionary contributions, as defined by each plan. The Company’s total contributions to these plans for the three months ended September 30, 2019 and 2018 was $4,158 and $1,661 , respectively. The Company’s total contributions to these plans for the nine months ended September 30, 2019 and 2018 was $23,461 and $8,647 , respectively. Self-Insured Medical Plan The Company is self-insured for health insurance coverage for all of its active employees. Estimated liabilities for health and medical claims are recorded based on the Company’s historical experience and include a component for incurred but not paid claims. During the three months ended September 30, 2019 and 2018 , the Company incurred total expenses of $20,976 and $8,468 , respectively, which primarily includes claims processed and an estimate for claims incurred but not paid. During the nine months ended September 30, 2019 and 2018 , the Company incurred total expenses of $58,873 and $22,496 , respectively, which primarily includes claims processed and an estimate for claims incurred but not paid.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2019
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions On June 14, 2019, the Company entered into a Credit Agreement which provides for the Term Loan Credit Facility as provided by a group of existing shareholders as of the agreement date. Refer to Note 11 for additional disclosures. On July 19, 2019, in connection with Blackjewel’s bankruptcy filing, the U.S. Bankruptcy Court approved debtor-in-possession (“DIP”) financing of $2,900 with DIP lenders, Highbridge Capital Management, LLC and Whitebox Advisors LLC, which are existing shareholders of the Company. The Company entered into an arrangement on July 19, 2019 to purchase the obligations under the DIP financing at the request of the lenders thereunder pursuant to certain terms and conditions. Refer to Note 20 for further developments within subsequent event disclosures. On September 12, 2019, the Company entered into a common stock repurchase agreement with Whitebox Multi-Strategy Partners, L.P., Whitebox Asymmetric Partners, L.P., Whitebox Credit Partners, L.P. and Whitebox Institutional Partners, L.P., which are existing shareholders of the Company. Refer to Note 10 for additional disclosures. There were no other material related party transactions for the nine months ended September 30, 2019 .

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
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 Condensed 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 financing and operating leases with varying terms. Refer to Note 9 for further information on leases. In addition, the Company leases mineral interests and surface rights from land owners under various terms and royalty rates. Coal royalty expense was $21,868 and $5,439 for the three months ended September 30, 2019 and 2018. Coal royalty expense was $73,119 and $19,182 for the nine months ended September 30, 2019 and 2018. Minimum royalty obligations under coal leases total $2,124 , $14,656 , $13,725 , $11,830 , $10,810 , and $13,441 for the remainder of 2019, 2020, 2021, 2022, 2023, and after 2023, respectively. Other Commitments The Company has obligations under certain coal purchase agreements that contain minimum quantities to be purchased in the remainder of 2019 and 2020 totaling an estimated $98,936 and $30,466 , respectively, which includes an estimated $29,181 in the remainder of 2019 related to contractually committed variable priced tons from vendors with historical performance resulting in less than 20% of the committed tonnage being delivered. The Company has obligations under certain coal transportation agreements that contain minimum quantities to be shipped in 2020 totaling $21,967 . The Company also has obligations under certain equipment purchase agreements that contain minimum quantities to be purchased in the remainder of 2019, 2020, and 2022 totaling $26,638 , $11,014 , and $279 , respectively. Contingencies Extensive regulation of the impacts of mining on the environment and of maintaining workplace safety has had and is expected to continue to 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. Per terms of the Back-to-Back Coal Supply Agreements, the Company is required to purchase and sell coal in the remainder of 2019 and 2020 totaling $6,823 and $9,175 , respectively. For the three months ended September 30, 2019 and 2018, the Company purchased and sold 14 and 877 tons, respectively, totaling $148 and $9,785 , respectively, under the Back-to-Back Coal Supply Agreements. For the nine months ended September 30, 2019 and 2018, the Company purchased and sold 735 and 5,527 tons, respectively, totaling $7,890 and $60,124 , respectively, under the Back-to-Back Coal Supply Agreements. In October 2018, the State of Wyoming Department of Revenue invoiced Blackjewel for approximately $7,800 in severance taxes owed by Blackjewel in connection with the Wyoming properties it previously acquired from the Company. In connection with this invoice, the Department purported to assert liens over Contura Coal West, LLC, one of the Company’s subsidiaries. On October 28, 2018, Blackjewel entered into a payment plan agreement with the State of Wyoming Department of Revenue to address the severance taxes owed by Blackjewel. On July 1, 2019, Blackjewel announced a Chapter 11 bankruptcy filing. In connection with Blackjewel’s bankruptcy filing and the subsequent closing of the Eagle Specialty Materials Transaction (refer to Note 20 Subsequent Events), the Company paid $13,500 to Campbell County, Wyoming for accrued ad valorem back taxes for 2018 and was released from all claims related thereto. The State of Wyoming Department of Revenue also released the Company of any outstanding claims related to state tax obligations arising from or related to the Belle Ayr and Eagle Butte mines for any period through and including the closing date of the transaction. Future Federal Income Tax Refunds As of September 30, 2019 , the Company has recorded $68,774 of federal income tax receivable and $68,774 of federal deferred tax asset related to AMT Credits. In addition, the Company has recorded a non-current federal income tax receivable of $43,770 related to an NOL carryback claim. Because the federal government was a creditor in the Alpha Natural Resources, Inc. (“Predecessor Alpha”) bankruptcy proceedings, it is possible that the federal government could withhold some or all of the tax refund attributable to the NOL carryback claim and the refundable AMT Credits and assert a right to setoff the tax refund and refundable credits against its prepetition bankruptcy claims. (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. However, the underlying liabilities that they secure, such as asset retirement obligations, workers’ compensation liabilities, and royalty obligations, are reflected in the Company’s Condensed Consolidated Balance Sheets. The Company is required to provide financial assurance in order to perform the post-mining reclamation required by its mining permits, pay its federal production royalties, pay workers’ compensation claims under workers’ compensation laws in various states, pay federal black lung benefits, and perform certain other obligations. In order to provide the required financial assurance, the Company generally uses surety bonds for post-mining reclamation and workers’ compensation obligations. The Company can also use bank letters of credit to collateralize certain obligations. As of September 30, 2019 , the Company had outstanding surety bonds with a total face amount of $570,365 to secure various obligations and commitments, including $227,410 related to the PRB. To secure the Company’s reclamation-related obligations, the Company currently has $117,104 of collateral supporting these obligations. The Company expects to have approximately $9,000 cash collateral, comprised of long-term restricted cash and long-term deposits, returned related to the release of its surety bonds related to the PRB. Refer to Note 20 for further developments within subsequent event disclosures. Amounts included in restricted cash represent cash deposits that are restricted as to withdrawal as required by certain agreements entered into by the Company and provide collateral in the amounts of $95,724 , $31,231 , $89,993 , $1,160 , and $2,832 as of September 30, 2019 for securing the Company’s obligations under certain worker’s compensation, black lung, reclamation-related obligations, general liabilities, and financial guarantees, respectively, which have been written on the Company’s behalf. Additionally, the Company has $9,557 of short-term restricted cash held in escrow related to the Company’s contingent revenue obligation. Refer to Note 12 for further information regarding the contingent revenue obligation. The Company’s restricted cash is primarily invested in interest bearing accounts. This restricted cash is classified as both short-term and long-term on the Company’s Condensed Consolidated Balance Sheets. Amounts included in restricted investments consist of certificates of deposit, corporate bonds, and U.S. treasury bills that are restricted as to withdrawal as required by certain agreements entered into by the Company and provide collateral in the amounts of $3,091 and $15,558 as of September 30, 2019 for securing the Company’s obligations under certain worker’s compensation and reclamation-related obligations, respectively, which have been written on the Company’s behalf. These restricted investments are classified as long-term on the Company’s Condensed Consolidated Balance Sheets. Deposits represent cash deposits held at third parties as required by certain agreements entered into by the Company to provide cash collateral. At September 30, 2019 , the Company had cash collateral in the form of deposits in the amounts of $11,552 and $1,903 to secure the Company’s obligations under reclamation-related obligations and various other operating agreements, respectively. Additionally, the Company held a $3,050 purchase deposit. Refer to Note 20 . These deposits are classified as both short-term and long-term on the Company’s Condensed Consolidated Balance Sheets. As of September 30, 2019 , the Company had real property collateralizing $26,749 of reclamation bonds. Refer to Note 20 for further developments within subsequent event disclosures. The Company meets frequently with its surety providers and has discussions with certain providers regarding the extent of and the terms of their participation in the program. These discussions may cause the Company to shift surety bonds between providers or to alter the terms of their participation in our program. To the extent that surety bonds become unavailable or the Company’s surety bond providers require additional collateral, the Company would seek to secure its obligations with letters of credit, cash deposits or other suitable forms of collateral. The Company’s failure to maintain, or inability to acquire, surety bonds or to provide a suitable alternative would have a material adverse effect on its liquidity. These failures could result from a variety of factors including lack of availability, higher cost or unfavorable market terms of new surety bonds, and the exercise by third-party surety bond issuers of their right to refuse to renew the surety. Letters of Credit As of September 30, 2019 , the Company had $48,634 letters of credit outstanding under the Amended and Restated Asset-Based Revolving Credit Agreement. Additionally, as of September 30, 2019 , the Company had $102,990 letters of credit outstanding under the Amended and Restated Letter of Credit Agreement dated November 9, 2018 between ANR, Inc. and Citibank, N.A. and $613 letters of credit outstanding under the Credit and Security Agreement dated June 30, 2017, and related amendments, between ANR, Inc. and First Tennessee Bank National Association. (d) Legal Proceedings The Company is party to legal proceedings from time to time. These proceedings, as well as governmental examinations, could 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, securities-related matters and employment matters. While some legal matters may specify the damages claimed by the plaintiffs, many seek an unquantified amount of damages. 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, if such legal matters arise in the future, 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. The Company records accruals based on an estimate of the ultimate outcome of these matters, but these estimates can be difficult to determine and involve significant judgment.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment Information	Segment Information The Company extracts, processes and markets met and thermal coal from surface and deep mines for sale to steel and coke producers, industrial customers, and electric utilities. The Company conducts mining operations only in the United States with mines in Central and Northern Appalachia. As of September 30, 2019 , the Company has three reportable segments: CAPP - Met, CAPP - Thermal, and NAPP. CAPP - Met consists of eight active mines and two preparation plants in Virginia, seventeen active mines and six preparation plants in West Virginia, as well as expenses associated with certain idled/closed mines. CAPP - Thermal consists of five active mines and three preparation plants in West Virginia, as well as expenses associated with certain idled/closed mines. NAPP consists of one active mine in Pennsylvania and one preparation plant, as well as expenses associated with one closed mine. Prior to the third quarter of 2019, the Company had four reportable segments: CAPP - Met, CAPP - Thermal, NAPP, and Trading and Logistics. As a result of the changes in key operating personnel during the third quarter of 2019 including changes to the Company’s Chief Operating Decision Maker (“CODM”), the Company was required to re-evaluate its previous conclusions with respect to its segment reporting during the period. To conform to the current period reportable segments presentation, the prior periods have been restated to reflect the change in reportable segments. Prior to the Merger, the Company had three reportable segments: CAPP, NAPP, and Trading and Logistics. In addition to the three reportable segments, the All Other category includes general corporate overhead and corporate assets and liabilities and the elimination of certain intercompany activity. The operating results of these reportable segments are regularly reviewed by the CODM, who is the Chief Executive Officer of the Company. Segment operating results and capital expenditures for the three months ended September 30, 2019 were as follows: Three Months Ended September 30, 2019 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Total revenues $ 373,356 $ 80,432 $ 71,446 $ 630 $ 525,864 Depreciation, depletion, and amortization $ 38,212 $ 13,972 $ 6,241 $ 2,417 $ 60,842 Amortization of acquired intangibles, net $ 4,765 $ (3,359 ) $ 908 $ — $ 2,314 Adjusted EBITDA $ 58,796 $ 1,954 $ (4,152 ) $ (16,575 ) $ 40,023 Capital expenditures $ 47,316 $ 5,706 $ 7,114 $ 165 $ 60,301 Segment operating results and capital expenditures for the three months ended September 30, 2018 were as follows: Three Months Ended September 30, 2018 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Total revenues $ 378,259 $ — $ 68,950 $ 662 $ 447,871 Depreciation, depletion, and amortization $ 5,658 $ — $ 5,298 $ 185 $ 11,141 Amortization of acquired intangibles, net $ — $ — $ 1,158 $ — $ 1,158 Adjusted EBITDA $ 47,897 $ — $ 972 $ (10,063 ) $ 38,806 Capital expenditures $ 7,984 $ — $ 10,270 $ 119 $ 18,373 Segment operating results and capital expenditures for the nine months ended September 30, 2019 were as follows: Nine Months Ended September 30, 2019 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Total revenues $ 1,340,684 $ 225,698 $ 222,750 $ 2,052 $ 1,791,184 Depreciation, depletion, and amortization $ 113,714 $ 44,586 $ 19,390 $ 7,237 $ 184,927 Amortization of acquired intangibles, net $ 5,816 $ (12,142 ) $ 1,614 $ — $ (4,712 ) Adjusted EBITDA $ 283,483 $ 8,704 $ 21,900 $ (49,930 ) $ 264,157 Capital expenditures $ 105,008 $ 13,365 $ 23,317 $ 2,493 $ 144,183 Segment operating results and capital expenditures for the nine months ended September 30, 2018 were as follows: Nine Months Ended September 30, 2018 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Total revenues $ 1,240,516 $ — $ 215,710 $ 2,895 $ 1,459,121 Depreciation, depletion, and amortization $ 17,636 $ — $ 15,761 $ 554 $ 33,951 Amortization of acquired intangibles, net $ — $ — $ 12,468 $ — $ 12,468 Adjusted EBITDA $ 235,151 $ — $ 19,161 $ (30,386 ) $ 223,926 Capital expenditures $ 23,829 $ — $ 32,611 $ 282 $ 56,722 The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for the three months ended September 30, 2019 : Three Months Ended September 30, 2019 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Net income (loss) from continuing operations $ 13,033 $ (11,338 ) $ (12,304 ) $ (32,952 ) $ (43,561 ) Interest expense 84 6 1 18,756 18,847 Interest income (4 ) — (15 ) (1,744 ) (1,763 ) Income tax benefit — — — (3,102 ) (3,102 ) Depreciation, depletion and amortization 38,212 13,972 6,241 2,417 60,842 Merger related costs — — — 68 68 Non-cash stock compensation expense 348 3 — 2,387 2,738 Mark-to-market adjustment - acquisition-related obligations — — — (3,238 ) (3,238 ) Accretion on asset retirement obligations 2,326 2,670 1,017 833 6,846 Asset impairment 32 — — — 32 Amortization of acquired intangibles, net 4,765 (3,359 ) 908 — 2,314 Adjusted EBITDA $ 58,796 $ 1,954 $ (4,152 ) $ (16,575 ) $ 40,023 The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for the three months ended September 30, 2018 : Three Months Ended September 30, 2018 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Net income (loss) from continuing operations $ 41,694 $ — $ (5,923 ) $ (21,760 ) $ 14,011 Interest expense 4 — (490 ) 9,040 8,554 Interest income (7 ) — (12 ) (488 ) (507 ) Income tax expense — — — 12 12 Depreciation, depletion and amortization 5,658 — 5,298 185 11,141 Merger related costs — — — 1,181 1,181 Non-cash stock compensation expense — — — 1,885 1,885 Gain on settlement of acquisition-related obligations — — — (118 ) (118 ) Accretion on asset retirement obligations 548 — 941 — 1,489 Amortization of acquired intangibles, net — — 1,158 — 1,158 Adjusted EBITDA $ 47,897 $ — $ 972 $ (10,063 ) $ 38,806 The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for the nine months ended September 30, 2019 : Nine Months Ended September 30, 2019 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Net income (loss) from continuing operations $ 154,020 $ (34,675 ) $ (2,118 ) $ (128,498 ) $ (11,271 ) Interest expense 306 16 2 49,755 50,079 Interest income (12 ) — (38 ) (5,534 ) (5,584 ) Income tax benefit — — — (8,880 ) (8,880 ) Depreciation, depletion and amortization 113,714 44,586 19,390 7,237 184,927 Merger related costs — — — 1,055 1,055 Non-cash stock compensation expense 1,127 60 — 6,276 7,463 Mark-to-market adjustment - acquisition-related obligations — — — (288 ) (288 ) Accretion on asset retirement obligations 6,986 7,401 3,050 2,488 19,925 Loss on modification and extinguishment of debt — — — 26,459 26,459 Asset impairment (1) 5,858 — — — 5,858 Cost impact of coal inventory fair value adjustment (2) 4,751 3,458 — — 8,209 Gain on assets acquired in an exchange transaction (3) (9,083 ) — — — (9,083 ) Amortization of acquired intangibles, net 5,816 (12,142 ) 1,614 — (4,712 ) Adjusted EBITDA $ 283,483 $ 8,704 $ 21,900 $ (49,930 ) $ 264,157 (1) Asset impairment primarily related to the write-off of prepaid purchased coal from Blackjewel as a result of Blackjewel’s Chapter 11 bankruptcy filing on July 1, 2019. Refer to Note 20 for further developments within subsequent event disclosures. (2) The cost impact of the coal inventory fair value adjustment as a result of the Alpha Merger was completed during the three months ended June 30, 2019. (3) During the nine months ended September 30, 2019 , the Company entered into an exchange transaction which primarily included the release of the PRB overriding royalty interest owed to the Company in exchange for met coal reserves which resulted in a gain of $9,083 . The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for the nine months ended September 30, 2018 : Nine Months Ended September 30, 2018 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Net income (loss) from continuing operations $ 230,898 $ — $ (11,028 ) $ (72,917 ) $ 146,953 Interest expense 316 — (839 ) 27,061 26,538 Interest income (35 ) — (24 ) (770 ) (829 ) Income tax expense — — — 133 133 Depreciation, depletion and amortization 17,636 — 15,761 554 33,951 Merger related costs — — — 5,064 5,064 Management restructuring costs (1) — — — 2,659 2,659 Non-cash stock compensation expense — — — 8,240 8,240 Gain on settlement of acquisition-related obligations — — — (410 ) (410 ) Gain on sale of disposal group (2) (16,386 ) — — — (16,386 ) Accretion on asset retirement obligations 2,722 — 2,823 — 5,545 Amortization of acquired intangibles, net — — 12,468 — 12,468 Adjusted EBITDA $ 235,151 $ — $ 19,161 $ (30,386 ) $ 223,926 (1) Management restructuring costs are related to severance expense associated with senior management changes in the nine months ended September 30, 2018 . (2) During the fourth quarter of 2017, the Company entered into an asset purchase agreement to sell a disposal group (comprised of property, plant and equipment and associated asset retirement obligations) within the CAPP - Met segment. From the date the Company entered into the asset purchase agreement through the transaction close date, the property, plant and equipment and associated asset retirement obligations were classified as held for sale in amounts representing the fair value of the disposal group. Upon permit transfer, the transaction closed on April 2, 2018. The Company paid $10,000 in connection with the transaction, which was paid into escrow on March 27, 2018 and transferred to the buyer at the transaction close date, and expects to pay a series of additional cash payments in the aggregate amount of $1,500 , per the terms stated in the agreement, and recorded a gain on sale of $16,386 within other expenses (income) within the Condensed Consolidated Statements of Operations. No asset information has been provided for these reportable segments as the CODM does not regularly review asset information by reportable segment. The Company markets produced, processed and purchased coal to customers in the United States and in international markets, primarily India, Brazil, Netherlands, Turkey, and France. Export coal revenues were the following: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Total coal revenues $ 523,987 $ 443,005 $ 1,784,775 $ 1,446,538 Export coal revenues (1) $ 261,815 $ 384,597 $ 967,959 $ 1,267,642 Export coal revenues as % of total coal revenues 50 % 87 % 54 % 88 % (1) The amounts for the three months ended September 30, 2018 include $62,929 , $58,402 , and $56,519 of export coal revenues from external customers in India, Turkey, and Brazil, respectively, recorded within the CAPP - Met and NAPP segments. The amounts for the nine months ended September 30, 2019 include $228,754 of export coal revenues from external customers in India, recorded within the CAPP - Met, CAPP - Thermal, and NAPP segments. The amounts for the nine months ended September 30, 2018 include $352,344 and $218,486 of export coal revenues from external customers in India and Brazil, respectively, recorded within the CAPP - Met and NAPP segments. Revenue is tracked within the Company’s accounting records based on the product destination. The Company sold 440 and 1,705 tons of coal purchased from third parties, excluding tons sold related to the Back-to-Back Coal Supply Agreements, for the three months ended September 30, 2019 and 2018, respectively, representing approximately 8% and 44% , respectively, of total coal sales volume during such periods. The Company sold 1,815 and 4,938 tons of coal purchased from third parties, excluding tons sold related to the Back-to-Back Coal Supply Agreements, for the nine months ended September 30, 2019 and 2018, respectively, representing approximately 10% and 41% , respectively, of total coal sales volume during such periods. The Company purchased 1,156 and 3,451 tons of this coal from Alpha during the three and nine months ended September 30, 2018 . Additionally, one of the Company’s customers had an outstanding balance in excess of 10% of the total accounts receivable balance as of September 30, 2019 , and two of the Company’s customers had outstanding balances each in excess of 10% of the total accounts receivable balance as of December 31, 2018.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Closing of Transaction With Eagle Specialty Materials Related To Powder River Basin mines On October 2, 2019, the Bankruptcy Court approved the sale by Blackjewel of the Belle Ayr and Eagle Butte mines (the “Western Mines” or “Western Assets”) to Eagle Specialty Materials (“ESM”), an affiliate of FM Coal, LLC (“FM Coal”). The closing of the ESM acquisition occurred on October 18, 2019. As disclosed in Note 3 , the Company was the former owner of the Western Assets. As the mine permit transfer process relating to the Company’s sale of the Western Assets to Blackjewel had not been completed prior to Blackjewel’s filing for Chapter 11 bankruptcy protection, the Company remains the permitholder in good standing for both mines and maintained surety bonding to cover related reclamation and other obligations. As of September 30, 2019, the Company’s asset retirement obligation with respect to the Western Assets totaled $151,902 . In connection with ESM’s acquisition of the Western Assets from Blackjewel, on October 18, 2019, Contura and ESM finalized an agreement (the “ESM Transaction”) which provided, among other items, for the eventual transfer of the Western Asset permits from Contura to ESM and the assumption by ESM of the related reclamation obligations. In connection with the closing of the ESM Transaction, the surety bonding previously maintained by the Company for the benefit of the Wyoming Department of Environmental Quality (“DEQ”) was released and has been replaced with substitute surety bonds arranged for by ESM in the amount of approximately $238,000 . In accordance with separate agreements with ESM’s surety providers, the Company has no liability with respect to the substitute surety bonds. In addition, pursuant to an agreement with ESM, FM Coal and the United States Department of Interior’s Office of Surface Mining, Reclamation and Enforcement (“OSM”), OSM has agreed that the Company would not be linked to any future bond forfeiture related to the mines nor any Surface Mining Control and Reclamation Act of 1977 violations by ESM prior to permit transfer. ESM is expected to operate the mines during the permit transfer process and has agreed to use commercially reasonable efforts to cause the permits to be transferred as promptly as possible. As Blackjewel’s surety bonds were also released in connection with the transaction, the Company’s $44,800 backstop of Blackjewel’s bonding program and $18,800 supporting letters of credit are in the process of being released. Pursuant to the terms of the ESM Transaction, the Company agreed to pay ESM $90,000 ( $81,300 at closing and an additional $8,700 into escrow pursuant to terms to be mutually agreed upon between the parties). In addition, the Company agreed to finalize the conveyance of certain Wyoming real property to ESM upon release of such property as collateral by the DEQ, waive its rights to the remaining $3,050 purchase deposit provided to Blackjewel in connection with the stalking horse agreement and pay certain Blackjewel DIP lenders $3,008 of principal and interest pursuant to an existing agreement. Refer to Note 17 . ESM agreed to indemnify the Company and its affiliates against all reclamation liabilities related to the Western Assets and against claims by the federal government, the State of Wyoming or Campbell County, Wyoming for royalties, ad valorem taxes and other amounts relating to the Western Assets for the period beginning on December 8, 2017. Prior to the transfer of the Western Asset permits to ESM, the Company will continue to have potential risk with respect to the related reclamation obligations. However, given (i) the release of the Company’s bonding obligations described above and the posting of substitute bonds by ESM, (ii) the agreement with ESM’s surety providers that release the Company from liability with respect to the substitute bonds or the obligations secured thereby, (iii) the terms of the OSM agreement, (iv) the terms on which ESM is authorized to operate pursuant to the permits and (v) the ESM indemnity with respect to the reclamation obligations, the Company expects the remaining risk to be low. As a result, following the closing of the ESM Transaction and payment of amounts to ESM, the Company’s remaining reclamation obligation will be reduced to zero. The Company will closely monitor the permit transfer process and periodically re-assess its reclamation obligations as required. The Company expects to have approximately $9,000 of cash collateral returned related to the release of its surety bonds. Additionally, in connection with the closing of the ESM Transaction, the Company paid $13,500 to Campbell County, Wyoming for accrued ad valorem back taxes for 2018 and was released from all claims related thereto. Pursuant to an agreement with ESM, the State of Wyoming Department of Revenue and Blackjewel, the State of Wyoming Department of Revenue released the Company of any outstanding claims related to state tax obligations arising from or related to the Western Mines for any period through and including the closing date of the transaction.

Business and Basis of Present_2

Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation Together, the condensed consolidated statements of operations, comprehensive (loss) income, balance sheet, cash flows and stockholders’ equity for the Company are referred to as the “Condensed Consolidated Financial Statements.” The Condensed Consolidated Financial Statements are also referenced across periods as “Condensed Consolidated Balance Sheets,” “Condensed Consolidated Statements of Operations,” and “Condensed Consolidated Statements of Cash Flows.” The Condensed Consolidated Financial Statements include all wholly-owned subsidiaries’ results of operations for the three and nine months ended September 30, 2019 and 2018 . All significant intercompany transactions have been eliminated in consolidation. The accompanying interim Condensed Consolidated Financial Statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) and 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 the financial statements prepared in accordance with U.S. GAAP 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, 2019 are not necessarily indicative of the results to be expected for the year ending December 31, 2019 or any other period. These interim Condensed Consolidated Financial Statements should be read in conjunction with the Company’s Consolidated Financial Statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018.
Reclassifications	Reclassifications Accretion on asset retirement obligations has been reclassified in the prior year from cost of coal sales to a separate line item in the Condensed Consolidated Statements of Operations to conform to the current year presentation. Freight and handling costs has been reclassified in the prior year from a separate line item into cost of coal sales in the Condensed Consolidated Statements of Operations to conform to the current year presentation.
Unrestricted and Restricted Investments	Unrestricted and Restricted Investments: Amounts primarily consist of money market funds, other cash equivalents, certificates of deposit, corporate debt securities and U.S. treasury and agency securities classified as either trading securities or held-to-maturity securities. The trading securities are recorded initially at cost and adjusted to fair value at each reporting period. The trading securities’ unrealized gains and losses resulting from fair value adjustments are recorded in current period earnings or loss. The held-to-maturity securities are recorded at amortized cost with interest income recorded in current period earnings.
New Accounting Pronouncements	New Accounting Pronouncements Leases: I n February 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2016-02 , Leases (“ASU 2016-02”) . ASU 2016-02, along with related amendments issued from 2017 to 2019 (collectively, the “New Leases Standard”), requires a lessee to recognize a right-of-use asset and a lease liability on the balance sheet. The Company adopted ASU 2016-02 effective January 1, 2019 and elected the option to not restate comparative periods in transition and also elected the hindsight practical expedient, which allows the Company to use hindsight when considering lessee options to extend or terminate leases when determining the lease term of lease arrangements for classification purposes, and the package of practical expedients for all leases within the standard, which permits the Company not to reassess its prior conclusions about lease identification, lease classification and initial direct costs. Additionally, the Company elected the transition practical expedient to continue to account for existing and expired land easements at transition as executory contracts. Only land easements entered into or modified after the effective date of Accounting Standards Codification (“ASC”) 842 are accounted for as leases by the Company. As a result of the adoption, the Company recorded operating lease right-of-use assets and lease liabilities on our Condensed Consolidated Balance Sheet. The following table summarizes the impact of the adoption of ASC 842 to the Company’s Condensed Consolidated Balance Sheet: Balance at December 31, 2018 (1) Adjustments Balance at January 1, 2019 Assets Balance Sheet Classification Operating lease right-of-use assets Other non-current assets $ — $ 11,845 $ 11,845 Financing lease assets Property, plant, and equipment, net 9,786 — 9,786 Total lease assets $ 9,786 $ 11,845 $ 21,631 Liabilities Balance Sheet Classification Operating lease liabilities - current Accrued expenses and other current liabilities $ — $ 3,624 $ 3,624 Financing lease liabilities - current Current portion of long-term debt 2,110 — 2,110 Operating lease liabilities - long-term Other non-current liabilities — 8,221 8,221 Financing lease liabilities - long-term Long-term debt 4,313 — 4,313 Total lease liabilities $ 6,423 $ 11,845 $ 18,268 (1) Balances do not include measurement-period adjustments recorded during the nine months ended September 30, 2019 . Refer to Note 2 for further details on measurement-period adjustments recorded during the period. The adoption of ASC 842 did not have an impact on our Condensed Consolidated Statements of Operations, Condensed Consolidated Statements of Comprehensive (Loss) Income, or Condensed Consolidated Statements of Cash Flows. Refer to Note 9 for further disclosure requirements under the new standard. Credit Losses: In June 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Credit Losses (“ASU 2016-13”). ASU 2016-13, along with related amendments and improvements issued in 2018 and 2019, replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable supportable information to inform credit loss estimates. Management anticipates adopting the standard in the first quarter of 2020, although a significant impact to the Company’s financial results is not expected. Stock Compensation : In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting (“ASU 2018-07”). The amendments in this update expand the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. The Company adopted ASU 2018-07 during the first quarter of 2019. The adoption of this ASU did not have a material impact on the Company's Condensed Consolidated Financial Statements and related disclosures.

Business and Basis of Present_3

Business and Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of New Accounting Pronouncements	The following table summarizes the impact of the adoption of ASC 842 to the Company’s Condensed Consolidated Balance Sheet: Balance at December 31, 2018 (1) Adjustments Balance at January 1, 2019 Assets Balance Sheet Classification Operating lease right-of-use assets Other non-current assets $ — $ 11,845 $ 11,845 Financing lease assets Property, plant, and equipment, net 9,786 — 9,786 Total lease assets $ 9,786 $ 11,845 $ 21,631 Liabilities Balance Sheet Classification Operating lease liabilities - current Accrued expenses and other current liabilities $ — $ 3,624 $ 3,624 Financing lease liabilities - current Current portion of long-term debt 2,110 — 2,110 Operating lease liabilities - long-term Other non-current liabilities — 8,221 8,221 Financing lease liabilities - long-term Long-term debt 4,313 — 4,313 Total lease liabilities $ 6,423 $ 11,845 $ 18,268 (1) Balances do not include measurement-period adjustments recorded during the nine months ended September 30, 2019 . Refer to Note 2 for further details on measurement-period adjustments recorded during the period.

Mergers and Acquisitions (Table

Mergers and Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Schedule of Acquired Intangible Assets and Liabilities	The finalized purchase price of $688,534 has been allocated to the net tangible and intangible assets of Alpha Companies as follows: Provisional as of December 31, 2018 Adjustments Final Cash and cash equivalents $ 29,939 $ — $ 29,939 Trade and other receivables 60,714 — 60,714 Inventories 85,635 — 85,635 Short-term restricted cash 10,592 — 10,592 Other current assets 38,495 10,087 48,582 Property, plant, and equipment 504,852 (33,930 ) 470,922 Owned and leased mineral rights 516,201 23,571 539,772 Other intangible assets 154,041 4,363 158,404 Long-term restricted cash 182,049 — 182,049 Long-term restricted investments 28,809 — 28,809 Other non-current assets 68,022 (3,353 ) 64,669 Total assets $ 1,679,349 $ 738 $ 1,680,087 Accounts payable $ 69,049 $ (2,504 ) $ 66,545 Accrued expenses and other current liabilities 76,774 2,491 79,265 Long-term debt, including current portion 144,832 3,626 148,458 Acquisition related obligations 74,346 5,738 80,084 Pension obligations 158,005 3,596 161,601 Asset retirement obligation, including current portion 163,636 12,718 176,354 Deferred income taxes, including current portion 134,924 (8,484 ) 126,440 Other intangible liabilities 57,219 — 57,219 Other non-current liabilities 207,654 12,286 219,940 Total liabilities $ 1,086,439 $ 29,467 $ 1,115,906 Goodwill $ 95,624 $ 28,729 $ 124,353 Allocation of purchase price $ 688,534 $ — $ 688,534
Schedule of Intangible Assets and Weighted-Average Amortization	The following table represents the intangible assets and the weighted-average amortization periods as of the acquisition date: Final Weighted-Average Amortization Period In Years ) Mining permits $ 157,555 12.30 Above-market coal supply agreements 849 1.03 Below-market coal supply agreements (57,219 ) 2.10 Total acquired intangibles $ 101,185 10.16
Business Acquisition, Pro Forma Information	The following unaudited pro forma information has been prepared for illustrative purposes only and assumes the Merger occurred on January 1, 2017. The unaudited pro forma results have been prepared based on estimates and assumptions, which the Company believes are reasonable; however, they are not necessarily indicative of the consolidated results of operations had the Merger occurred on January 1, 2017, or of future results of operations. Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 As reported Pro forma As reported Pro forma Total revenues $ 447,871 $ 633,656 $ 1,459,121 $ 1,972,610 Income from continuing operations $ 14,011 $ 2,801 $ 146,953 $ 182,533 Basic income per common share: Income from continuing operations $ 1.45 $ 0.15 $ 15.30 $ 9.62 Diluted income per common share: Income from continuing operations $ 1.35 $ 0.14 $ 14.23 $ 9.26 Weighted average shares - basic 9,633,164 19,011,363 9,602,860 18,981,059 Weighted average shares - diluted 10,384,513 19,762,712 10,328,031 19,706,230

Discontinued Operations (Tables

Discontinued Operations (Tables)	9 Months Ended
	Sep. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	The major components of net loss from discontinued operations in the Condensed Consolidated Statements of Operations are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Revenues: Total revenues (1) $ 4 $ 139 $ 152 $ 1,254 Costs and expenses: Depreciation, depletion and amortization (2) $ — $ — $ 145,913 $ — Accretion on asset retirement obligations (3) $ 4,981 $ — $ 4,981 $ — Asset impairment (4) $ 694 $ — $ 17,162 $ — Selling, general and administrative expenses $ 4,666 $ 12 $ 4,673 $ 39 Other expenses $ 1,032 $ 1,078 $ 3,964 $ 3,453 Other non-major expense (income) items, net $ 147 $ 1,166 $ 432 $ 2,092 (1) Total revenues for the three and nine months ended September 30, 2019 and 2018 consisted entirely of other revenues. (2) The depreciation, depletion and amortization is related to an increase in the Company’s estimate of its asset retirement obligations with respect to the Eagle Butte and Belle Ayr mines as a result of Blackjewel’s bankruptcy filing. The Company remeasured its asset retirement obligations based on the expectation that the mining permits would not transfer to Blackjewel and Blackjewel would be unable to perform its contractual obligation to reclaim the properties. The increase in the asset retirement obligation was recorded to expense as the Company no longer owned the underlying mining assets. Refer to Note 20 Subsequent Events. (3) The accretion on asset retirement obligations is related to the asset retirement obligation as a result of the Blackjewel’s bankruptcy filing. Refer to the above disclosures for further details. (4) The asset impairment for the three and nine months ended September 30, 2019 is primarily related to the write-off of tax related indemnification receivables from Blackjewel. Refer to the disclosures below for further details. The major components of asset and liabilities that are classified as discontinued operations in the Condensed Consolidated Balance Sheets are as follows: September 30, 2019 December 31, 2018 Assets: Prepaid expenses and other current assets $ 3,401 $ 22,475 Liabilities: Trade accounts payable, accrued expenses and other current liabilities (1) $ 20,439 $ 21,892 Asset retirement obligations (2) $ 151,902 $ — Other non-current liabilities $ 96 $ 94 (1) The liabilities are primarily comprised of taxes for which the Company is considered to be the primary obligor but for which the Buyer was contractually obligated to pay. During the three and nine months ended September 30, 2019 , the Company recorded an impairment charge for the offsetting indemnification receivable as a result of the Blackjewel bankruptcy filing. (2) Refer to discussion of asset retirement obligations in the table above. The major components of cash flows related to discontinued operations are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Other significant operating non-cash items related to discontinued operations: Depreciation, depletion and amortization $ — $ — $ 145,913 $ — Accretion on asset retirement obligations $ 4,981 $ — $ 4,981 $ —

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables disaggregate the Company’s coal revenues by product category and by market to depict how the nature, amount, timing, and uncertainty of the Company’s coal revenues and cash flows are affected by economic factors: Three Months Ended September 30, 2019 Met Thermal Total Export coal revenues $ 248,628 $ 13,187 $ 261,815 Domestic coal revenues 137,146 125,026 262,172 Total coal revenues $ 385,774 $ 138,213 $ 523,987 Three Months Ended September 30, 2018 Met Thermal Total Export coal revenues $ 371,749 $ 12,848 $ 384,597 Domestic coal revenues 15,292 43,116 58,408 Total coal revenues $ 387,041 $ 55,964 $ 443,005 Nine Months Ended September 30, 2019 Met Thermal Total Export coal revenues $ 928,390 $ 39,569 $ 967,959 Domestic coal revenues 429,457 387,359 816,816 Total coal revenues $ 1,357,847 $ 426,928 $ 1,784,775 Nine Months Ended September 30, 2018 Met Thermal Total Export coal revenues $ 1,239,008 $ 28,634 $ 1,267,642 Domestic coal revenues 38,156 140,740 178,896 Total coal revenues $ 1,277,164 $ 169,374 $ 1,446,538
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied as of September 30, 2019 . Remainder of 2019 2020 2021 2022 2023 2024 Total Estimated coal revenues $ 64,916 $ 357,281 $ 196,240 $ 138,444 $ 130,267 $ 46,000 $ 933,148
Contract with Customer, Liability	The following table includes the opening and closing balances of contract assets from modifications with contracts with customers, which are included within prepaid expenses and other current assets on the Company’s Condensed Consolidated Balance Sheets: September 30, 2019 December 31, 2018 Contract assets (1) $ 985 $ 950 (1) Amounts primarily relate to payments made upon modification of coal contracts.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive (Loss) Income (Tables)	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following tables summarize the changes to accumulated other comprehensive (loss) income during the nine months ended September 30, 2019 and 2018 : Balance January 1, 2019 Other comprehensive income (loss) before reclassifications Amounts reclassified from accumulated other comprehensive (loss) income Balance September 30, 2019 Employee benefit costs $ (23,130 ) $ 458 $ 532 $ (22,140 ) Balance January 1, 2018 Other comprehensive income (loss) before reclassifications Amounts reclassified from accumulated other comprehensive (loss) income Balance September 30, 2018 Employee benefit costs $ (1,948 ) $ (128 ) $ 117 $ (1,959 ) The following table summarizes the amounts reclassified from accumulated other comprehensive (loss) income and the Condensed Consolidated Statements of Operations line items affected by the reclassification during the three and nine months ended September 30, 2019 and 2018 : Details about accumulated other comprehensive (loss) income components Amounts reclassified from accumulated other comprehensive (loss) income Affected line item in the Condensed Consolidated Statements of Operations Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Employee benefit costs: Amortization of actuarial loss $ 258 $ 39 $ 719 $ 117 (1) Miscellaneous loss, net Income tax expense (67 ) — (187 ) — Income tax benefit (expense) Total, net of income tax $ 191 $ 39 $ 532 $ 117 (1) These accumulated other comprehensive (loss) income components are included in the computation of net periodic benefit costs for pension, black lung, life insurance and other employee benefit plans. Refer to Note 16 .

Net (Loss) Income Per Share (Ta

Net (Loss) Income Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table presents the net (loss) income per common share for the three and nine months ended September 30, 2019 and 2018 : Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Net (loss) income (Loss) income from continuing operations $ (43,561 ) $ 14,011 $ (11,271 ) $ 146,953 Loss from discontinued operations (24,971 ) (2,117 ) (164,107 ) (4,330 ) Net (loss) income $ (68,532 ) $ 11,894 $ (175,378 ) $ 142,623 Basic Weighted average common shares outstanding - basic 19,025,462 9,633,164 19,014,974 9,602,860 Basic (loss) income per common share: (Loss) income from continuing operations $ (2.29 ) $ 1.45 $ (0.59 ) $ 15.30 Loss from discontinued operations (1.31 ) (0.22 ) (8.63 ) (0.45 ) Net (loss) income $ (3.60 ) $ 1.23 $ (9.22 ) $ 14.85 Diluted Weighted average common shares outstanding - basic 19,025,462 9,633,164 19,014,974 9,602,860 Diluted effect of warrants — 304,243 — 270,611 Diluted effect of stock options — 260,653 — 265,794 Diluted effect of restricted share units, restricted stock shares and performance-based restricted share units — 186,453 — 188,766 Weighted average common shares outstanding - diluted 19,025,462 10,384,513 19,014,974 10,328,031 Diluted (loss) income per common share: (Loss) income from continuing operations $ (2.29 ) $ 1.35 $ (0.59 ) $ 14.23 Loss from discontinued operations (1.31 ) (0.20 ) (8.63 ) (0.42 ) Net (loss) income $ (3.60 ) $ 1.15 $ (9.22 ) $ 13.81

Inventories, Net (Tables)

Inventories, Net (Tables)	9 Months Ended
	Sep. 30, 2019
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventories, net consisted of the following: September 30, 2019 December 31, 2018 Raw coal $ 31,924 $ 33,607 Saleable coal 115,290 63,767 Materials, supplies and other, net 25,377 24,591 Total inventories, net $ 172,591 $ 121,965

Goodwill and Acquired Intangi_2

Goodwill and Acquired Intangibles (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangibles	The balances and respective balance sheet classifications of such assets and liabilities as of September 30, 2019 and December 31, 2018, net of accumulated amortization, are set forth in the following tables: September 30, 2019 Assets (1) Liabilities (2) Net Total Coal supply agreements, net $ 2,450 $ (8,978 ) $ (6,528 ) Acquired mine permits, net 136,275 — 136,275 Total $ 138,725 $ (8,978 ) $ 129,747 December 31, 2018 Assets (1) Liabilities (2) Net Total Coal supply agreements, net $ 4,687 $ (33,912 ) $ (29,225 ) Acquired mine permits, net 149,897 — 149,897 Total $ 154,584 $ (33,912 ) $ 120,672 (1) Included within other acquired intangibles, net of accumulated amortization on the Company’s Condensed Consolidated Balance Sheets. (2) Included within other non-current liabilities on the Company’s Condensed Consolidated Balance Sheets.

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Right-of-use Assets and Lease Liabilities	As of September 30, 2019 , the Company had the following right-of-use assets and lease liabilities within the Company’s Condensed Consolidated Balance Sheets: September 30, 2019 Assets Balance Sheet Classification Financing lease assets Property, plant, and equipment, net $ 10,779 Operating lease right-of-use assets Other non-current assets 9,325 Total lease assets $ 20,104 Liabilities Balance Sheet Classification Financing lease liabilities - current Current portion of long-term debt $ 3,146 Operating lease liabilities - current Accrued expenses and other current liabilities 2,079 Financing lease liabilities - long-term Long-term debt 5,206 Operating lease liabilities - long-term Other non-current liabilities 7,246 Total lease liabilities $ 17,677
Lease Costs and Other Information	Total lease costs and other lease information for the three and nine months ended September 30, 2019 included the following: Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Lease cost (1) Finance lease cost: Amortization of leased assets $ 1,143 $ 2,796 Interest on lease liabilities 108 366 Operating lease cost 732 2,062 Short-term lease cost 494 1,474 Total lease cost $ 2,477 $ 6,698 (1) The Company had no variable lease costs or sublease income for the nine months ended September 30, 2019 . Nine Months Ended September 30, 2019 Other information Cash paid for amounts included in the measurement of lease liabilities $ 6,862 Operating cash flows from finance leases $ 366 Operating cash flows from operating leases $ 3,536 Financing cash flows from finance leases $ 2,960 Right-of-use assets obtained in exchange for new finance lease liabilities $ 1,142 Lease Term and Discount Rate Weighted-average remaining lease term in months - finance leases 32.8 Weighted-average remaining lease term in months - operating leases 94.6 Weighted-average discount rate - finance leases 5.2 % Weighted-average discount rate - operating leases 10.9 %
Operating Lease Maturity	The following table summarizes the maturity of the Company’s lease liabilities on an undiscounted cash flow basis and a reconciliation to the lease liabilities recognized in the Company’s Condensed Consolidated Balance Sheet as of September 30, 2019 : Finance Leases Operating Leases Lease cost Remainder of 2019 $ 884 $ 785 2020 3,500 2,580 2021 2,864 1,961 2022 1,607 1,654 2023 97 1,193 Thereafter — 6,283 Total future minimum lease payments $ 8,952 $ 14,456 Imputed interest (600 ) (5,131 ) Present value of future minimum lease payments $ 8,352 $ 9,325
Finance Lease Maturity	The following table summarizes the maturity of the Company’s lease liabilities on an undiscounted cash flow basis and a reconciliation to the lease liabilities recognized in the Company’s Condensed Consolidated Balance Sheet as of September 30, 2019 : Finance Leases Operating Leases Lease cost Remainder of 2019 $ 884 $ 785 2020 3,500 2,580 2021 2,864 1,961 2022 1,607 1,654 2023 97 1,193 Thereafter — 6,283 Total future minimum lease payments $ 8,952 $ 14,456 Imputed interest (600 ) (5,131 ) Present value of future minimum lease payments $ 8,352 $ 9,325

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	Long-term debt consisted of the following: September 30, 2019 December 31, 2018 Term Loan Credit Facility - due November 2025 $ — $ 550,000 Term Loan Credit Facility - due June 2024 560,395 — LCC Note Payable 45,000 62,500 LCC Water Treatment Obligation 10,625 11,875 Other 9,755 8,395 Debt discount and issuance costs (32,947 ) (44,758 ) Total long-term debt 592,828 588,012 Less current portion (28,982 ) (42,743 ) Long-term debt, net of current portion $ 563,846 $ 545,269

Acquisition-Related Obligatio_2

Acquisition-Related Obligations (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Schedule of Acquisition-Related Obligations	Acquisition-related obligations consisted of the following: September 30, 2019 December 31, 2018 Contingent Revenue Obligation $ 55,703 $ 59,880 Environmental Settlement Obligations 16,305 19,306 Reclamation Funding Liability 12,000 22,000 Retiree Committee VEBA Funding Settlement Liability 1,000 3,500 UMWA Funds Settlement Liability 6,000 6,000 Discount (5,990 ) (10,356 ) Total acquisition-related obligations - long-term 85,018 100,330 Less current portion (33,165 ) (27,334 ) Acquisition-related obligations, net of current portion $ 51,853 $ 72,996

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	9 Months Ended
	Sep. 30, 2019
Asset Retirement Obligation Disclosure [Abstract]
Summary of Changes in Asset Retirement Obligations	The following table summarizes the changes in asset retirement obligations for the nine months ended September 30, 2019 : Total asset retirement obligations at December 31, 2018 $ 228,448 Measurement-period adjustments (1) 12,718 Accretion for the period 19,911 Sites added during the period 5,113 Revisions in estimated cash flows (43 ) Expenditures for the period (18,626 ) Total asset retirement obligations at September 30, 2019 247,521 Less current portion (24,365 ) Long-term portion $ 223,156 (1) Refer to Note 2 for additional information on the Merger and related measurement-period adjustments recorded during the nine months ended September 30, 2019 .

Fair Value of Financial Instr_2

Fair Value of Financial Instruments and Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements, Nonrecurring	The following tables set forth by level, within the fair value hierarchy, the Company’s acquisition-related obligations at fair value as of September 30, 2019 and December 31, 2018 : September 30, 2019 Carrying Amount (1) Total Fair Quoted Prices Significant Other Significant Retiree Committee VEBA Funding $ 956 $ 969 $ — $ — $ 969 UMWA Funds Settlement Liability 4,870 5,134 — — 5,134 Reclamation Funding Liability 10,321 10,814 — — 10,814 Environmental Settlement Obligations 13,168 13,188 — — 13,188 Total acquisition-related obligations $ 29,315 $ 30,105 $ — $ — $ 30,105 December 31, 2018 Carrying Amount (1) Total Fair Quoted Prices Significant Other Significant Retiree Committee VEBA Funding $ 3,337 $ 3,391 $ — $ — $ 3,391 UMWA Funds Settlement Liability 4,239 4,729 — — 4,729 Reclamation Funding Liability 18,106 19,362 — — 19,362 Environmental Settlement Obligations 14,768 14,936 — — 14,936 Total acquisition-related obligations $ 40,450 $ 42,418 $ — $ — $ 42,418 (1) Net of discounts. 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, 2019 and December 31, 2018 : September 30, 2019 Carrying Amount (1) Total Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Term Loan Credit Facility - due June 2024 $ 538,395 $ 546,386 $ 546,386 $ — $ — LCC Note Payable 36,483 36,517 — — 36,517 LCC Water Treatment Obligation 8,196 8,284 — — 8,284 Total long-term debt $ 583,074 $ 591,187 $ 546,386 $ — $ 44,801 December 31, 2018 Carrying Amount (1) Total Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Term Loan Credit Facility - due November 2025 $ 521,667 $ 540,375 $ 540,375 $ — $ — LCC Note Payable 49,361 50,606 — — 50,606 LCC Water Treatment Obligation 8,589 8,827 — — 8,827 Total long-term debt $ 579,617 $ 599,808 $ 540,375 $ — $ 59,433 (1) Net of debt discounts and debt issuance costs.
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table sets 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 basis as of September 30, 2019 and December 31, 2018 . 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, 2019 Total Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Contingent Revenue Obligation $ 55,703 $ — $ — $ 55,703 Trading securities $ 27,356 $ 1,624 $ 25,732 $ — December 31, 2018 Total Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Contingent Revenue Obligation $ 59,880 $ — $ — $ 59,880 The following table is a reconciliation of the financial and non-financial assets and liabilities that were accounted for at fair value on a recurring basis and that were categorized within Level 3 of the fair value hierarchy: December 31, 2018 Payments Measurement Period Adjustments (1) Loss Recognized in Earnings Transfer In (Out) of Level 3 Fair Value Hierarchy September 30, 2019 Contingent Revenue Obligation $ 59,880 $ (9,627 ) $ 5,738 $ (288 ) $ — $ 55,703 (1) Refer to Note 2 for additional information on the Merger and related measurement-period adjustments recorded during the nine months ended September 30, 2019 .

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2019
Compensation Related Costs [Abstract]
Schedule of Net Periodic Benefit Cost	The following table details the components of the net periodic (benefit) expense for black lung obligations: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Service cost $ 751 $ 194 $ 1,558 $ 582 Interest cost 1,567 174 3,386 521 Expected return on plan assets (17 ) — (49 ) — Amortization of net actuarial loss 72 50 162 150 Net periodic expense $ 2,373 $ 418 $ 5,057 $ 1,253 The following table details the components of the net periodic (benefit) expense for life insurance benefit obligations: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Interest cost $ 106 $ 97 $ 318 $ 291 Amortization of net actuarial gain (26 ) (11 ) (78 ) (33 ) Net periodic expense $ 80 $ 86 $ 240 $ 258 The following table details the components of the net periodic (benefit) expense for pension obligations: Three Months Ended September 30, Nine Months Ended September 30, 2019 2019 Interest cost $ 6,636 $ 19,929 Expected return on plan assets (7,011 ) (21,032 ) Amortization of net actuarial loss 199 597 Net periodic benefit $ (176 ) $ (506 )

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Schedule of Segment Operating Results and Capital Expenditures	Segment operating results and capital expenditures for the three months ended September 30, 2019 were as follows: Three Months Ended September 30, 2019 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Total revenues $ 373,356 $ 80,432 $ 71,446 $ 630 $ 525,864 Depreciation, depletion, and amortization $ 38,212 $ 13,972 $ 6,241 $ 2,417 $ 60,842 Amortization of acquired intangibles, net $ 4,765 $ (3,359 ) $ 908 $ — $ 2,314 Adjusted EBITDA $ 58,796 $ 1,954 $ (4,152 ) $ (16,575 ) $ 40,023 Capital expenditures $ 47,316 $ 5,706 $ 7,114 $ 165 $ 60,301 Segment operating results and capital expenditures for the three months ended September 30, 2018 were as follows: Three Months Ended September 30, 2018 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Total revenues $ 378,259 $ — $ 68,950 $ 662 $ 447,871 Depreciation, depletion, and amortization $ 5,658 $ — $ 5,298 $ 185 $ 11,141 Amortization of acquired intangibles, net $ — $ — $ 1,158 $ — $ 1,158 Adjusted EBITDA $ 47,897 $ — $ 972 $ (10,063 ) $ 38,806 Capital expenditures $ 7,984 $ — $ 10,270 $ 119 $ 18,373 Segment operating results and capital expenditures for the nine months ended September 30, 2019 were as follows: Nine Months Ended September 30, 2019 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Total revenues $ 1,340,684 $ 225,698 $ 222,750 $ 2,052 $ 1,791,184 Depreciation, depletion, and amortization $ 113,714 $ 44,586 $ 19,390 $ 7,237 $ 184,927 Amortization of acquired intangibles, net $ 5,816 $ (12,142 ) $ 1,614 $ — $ (4,712 ) Adjusted EBITDA $ 283,483 $ 8,704 $ 21,900 $ (49,930 ) $ 264,157 Capital expenditures $ 105,008 $ 13,365 $ 23,317 $ 2,493 $ 144,183 Segment operating results and capital expenditures for the nine months ended September 30, 2018 were as follows: Nine Months Ended September 30, 2018 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Total revenues $ 1,240,516 $ — $ 215,710 $ 2,895 $ 1,459,121 Depreciation, depletion, and amortization $ 17,636 $ — $ 15,761 $ 554 $ 33,951 Amortization of acquired intangibles, net $ — $ — $ 12,468 $ — $ 12,468 Adjusted EBITDA $ 235,151 $ — $ 19,161 $ (30,386 ) $ 223,926 Capital expenditures $ 23,829 $ — $ 32,611 $ 282 $ 56,722 The Company markets produced, processed and purchased coal to customers in the United States and in international markets, primarily India, Brazil, Netherlands, Turkey, and France. Export coal revenues were the following: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Total coal revenues $ 523,987 $ 443,005 $ 1,784,775 $ 1,446,538 Export coal revenues (1) $ 261,815 $ 384,597 $ 967,959 $ 1,267,642 Export coal revenues as % of total coal revenues 50 % 87 % 54 % 88 % (1) The amounts for the three months ended September 30, 2018 include $62,929 , $58,402 , and $56,519 of export coal revenues from external customers in India, Turkey, and Brazil, respectively, recorded within the CAPP - Met and NAPP segments. The amounts for the nine months ended September 30, 2019 include $228,754 of export coal revenues from external customers in India, recorded within the CAPP - Met, CAPP - Thermal, and NAPP segments. The amounts for the nine months ended September 30, 2018 include $352,344 and $218,486 of export coal revenues from external customers in India and Brazil, respectively, recorded within the CAPP - Met and NAPP segments. Revenue is tracked within the Company’s accounting records based on the product destination.
Reconciliation of Net Income (Loss) to Adjusted EBITDA	The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for the three months ended September 30, 2019 : Three Months Ended September 30, 2019 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Net income (loss) from continuing operations $ 13,033 $ (11,338 ) $ (12,304 ) $ (32,952 ) $ (43,561 ) Interest expense 84 6 1 18,756 18,847 Interest income (4 ) — (15 ) (1,744 ) (1,763 ) Income tax benefit — — — (3,102 ) (3,102 ) Depreciation, depletion and amortization 38,212 13,972 6,241 2,417 60,842 Merger related costs — — — 68 68 Non-cash stock compensation expense 348 3 — 2,387 2,738 Mark-to-market adjustment - acquisition-related obligations — — — (3,238 ) (3,238 ) Accretion on asset retirement obligations 2,326 2,670 1,017 833 6,846 Asset impairment 32 — — — 32 Amortization of acquired intangibles, net 4,765 (3,359 ) 908 — 2,314 Adjusted EBITDA $ 58,796 $ 1,954 $ (4,152 ) $ (16,575 ) $ 40,023 The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for the three months ended September 30, 2018 : Three Months Ended September 30, 2018 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Net income (loss) from continuing operations $ 41,694 $ — $ (5,923 ) $ (21,760 ) $ 14,011 Interest expense 4 — (490 ) 9,040 8,554 Interest income (7 ) — (12 ) (488 ) (507 ) Income tax expense — — — 12 12 Depreciation, depletion and amortization 5,658 — 5,298 185 11,141 Merger related costs — — — 1,181 1,181 Non-cash stock compensation expense — — — 1,885 1,885 Gain on settlement of acquisition-related obligations — — — (118 ) (118 ) Accretion on asset retirement obligations 548 — 941 — 1,489 Amortization of acquired intangibles, net — — 1,158 — 1,158 Adjusted EBITDA $ 47,897 $ — $ 972 $ (10,063 ) $ 38,806 The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for the nine months ended September 30, 2019 : Nine Months Ended September 30, 2019 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Net income (loss) from continuing operations $ 154,020 $ (34,675 ) $ (2,118 ) $ (128,498 ) $ (11,271 ) Interest expense 306 16 2 49,755 50,079 Interest income (12 ) — (38 ) (5,534 ) (5,584 ) Income tax benefit — — — (8,880 ) (8,880 ) Depreciation, depletion and amortization 113,714 44,586 19,390 7,237 184,927 Merger related costs — — — 1,055 1,055 Non-cash stock compensation expense 1,127 60 — 6,276 7,463 Mark-to-market adjustment - acquisition-related obligations — — — (288 ) (288 ) Accretion on asset retirement obligations 6,986 7,401 3,050 2,488 19,925 Loss on modification and extinguishment of debt — — — 26,459 26,459 Asset impairment (1) 5,858 — — — 5,858 Cost impact of coal inventory fair value adjustment (2) 4,751 3,458 — — 8,209 Gain on assets acquired in an exchange transaction (3) (9,083 ) — — — (9,083 ) Amortization of acquired intangibles, net 5,816 (12,142 ) 1,614 — (4,712 ) Adjusted EBITDA $ 283,483 $ 8,704 $ 21,900 $ (49,930 ) $ 264,157 (1) Asset impairment primarily related to the write-off of prepaid purchased coal from Blackjewel as a result of Blackjewel’s Chapter 11 bankruptcy filing on July 1, 2019. Refer to Note 20 for further developments within subsequent event disclosures. (2) The cost impact of the coal inventory fair value adjustment as a result of the Alpha Merger was completed during the three months ended June 30, 2019. (3) During the nine months ended September 30, 2019 , the Company entered into an exchange transaction which primarily included the release of the PRB overriding royalty interest owed to the Company in exchange for met coal reserves which resulted in a gain of $9,083 . The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for the nine months ended September 30, 2018 : Nine Months Ended September 30, 2018 CAPP - Met CAPP - Thermal NAPP All Other Consolidated Net income (loss) from continuing operations $ 230,898 $ — $ (11,028 ) $ (72,917 ) $ 146,953 Interest expense 316 — (839 ) 27,061 26,538 Interest income (35 ) — (24 ) (770 ) (829 ) Income tax expense — — — 133 133 Depreciation, depletion and amortization 17,636 — 15,761 554 33,951 Merger related costs — — — 5,064 5,064 Management restructuring costs (1) — — — 2,659 2,659 Non-cash stock compensation expense — — — 8,240 8,240 Gain on settlement of acquisition-related obligations — — — (410 ) (410 ) Gain on sale of disposal group (2) (16,386 ) — — — (16,386 ) Accretion on asset retirement obligations 2,722 — 2,823 — 5,545 Amortization of acquired intangibles, net — — 12,468 — 12,468 Adjusted EBITDA $ 235,151 $ — $ 19,161 $ (30,386 ) $ 223,926 (1) Management restructuring costs are related to severance expense associated with senior management changes in the nine months ended September 30, 2018 . (2) During the fourth quarter of 2017, the Company entered into an asset purchase agreement to sell a disposal group (comprised of property, plant and equipment and associated asset retirement obligations) within the CAPP - Met segment. From the date the Company entered into the asset purchase agreement through the transaction close date, the property, plant and equipment and associated asset retirement obligations were classified as held for sale in amounts representing the fair value of the disposal group. Upon permit transfer, the transaction closed on April 2, 2018. The Company paid $10,000 in connection with the transaction, which was paid into escrow on March 27, 2018 and transferred to the buyer at the transaction close date, and expects to pay a series of additional cash payments in the aggregate amount of $1,500 , per the terms stated in the agreement, and recorded a gain on sale of $16,386 within other expenses (income) within the Condensed Consolidated Statements of Operations.

Business and Basis of Present_4

Business and Basis of Presentation - ASC 842 (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 9,325	$ 11,845
Financing lease assets			$ 9,786
Financing lease assets	10,779	9,786
Total lease assets	20,104	21,631
Operating lease liabilities - current	2,079	3,624
Financing lease liabilities - current			2,110
Financing lease liabilities - current	3,146	2,110
Operating lease liabilities - long-term	7,246	8,221
Financing lease liabilities - long-term			4,313
Financing lease liabilities - long-term	5,206	4,313
Total lease liabilities			$ 6,423
Total lease liabilities	$ 17,677	18,268
Adjustments | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		11,845
Financing lease assets		0
Total lease assets		11,845
Operating lease liabilities - current		3,624
Financing lease liabilities - current		0
Operating lease liabilities - long-term		8,221
Financing lease liabilities - long-term		0
Total lease liabilities		$ 11,845

Business and Basis of Present_5

Business and Basis of Presentation - Unrestricted and Restricted Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Trading securities, unrestricted	$ 25,081
Trading securities, restricted	2,275
Held-to-maturity securities	$ 16,374	$ 29,137

Mergers and Acquisitions - Narr

Mergers and Acquisitions - Narrative (Details) - USD ($) $ in Thousands	Nov. 09, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Business Acquisition [Line Items]
Provisional goodwill		$ 124,353		$ 124,353		$ 95,624
(Loss) income from continuing operations		(43,561)	$ 14,011	(11,271)	$ 146,953
Alpha Companies
Business Acquisition [Line Items]
Preliminary purchase price allocation	$ 688,534
Provisional goodwill		124,353		124,353		$ 95,624
Measurement-period adjustments on provisional goodwill				28,729
Acquisition Costs | Alpha Companies
Business Acquisition [Line Items]
(Loss) income from continuing operations		$ 68	1,181	$ 1,055	5,064
Merger-related Costs | Alpha Companies
Business Acquisition [Line Items]
(Loss) income from continuing operations			$ 1,181		$ 5,064

Mergers and Acquisitions - Prel

Mergers and Acquisitions - Preliminary Purchase Price Allocation (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 124,353	$ 95,624
Alpha Companies
Business Acquisition [Line Items]
Cash and cash equivalents	29,939	29,939
Cash and cash equivalents	0
Trade and other receivables	60,714	60,714
Trade and other receivables	0
Inventories	85,635	85,635
Inventories	0
Short-term restricted cash	10,592	10,592
Short-term restricted cash	0
Other current assets	48,582	38,495
Other current assets	10,087
Property, plant, and equipment	470,922	504,852
Property, plant, and equipment	(33,930)
Owned and leased mineral rights	539,772	516,201
Owned and leased mineral rights	23,571
Other intangible assets	158,404	154,041
Other intangible assets	4,363
Long-term restricted cash	182,049	182,049
Long-term restricted cash	0
Long-term restricted investments	28,809	28,809
Long-term restricted investments	0
Other non-current assets	64,669	68,022
Other non-current assets	(3,353)
Total assets	1,680,087	1,679,349
Total assets	738
Accounts payable	66,545	69,049
Accounts payable	(2,504)
Accrued expenses and other current liabilities	79,265	76,774
Accrued expenses and other current liabilities	2,491
Long-term debt, including current portion	148,458	144,832
Long-term debt, including current portion	3,626
Acquisition related obligations	80,084	74,346
Acquisition related obligations	5,738
Pension obligations	161,601	158,005
Pension obligations	3,596
Asset retirement obligation, including current portion	176,354	163,636
Asset retirement obligation, including current portion	12,718
Deferred income taxes, including current portion	126,440	134,924
Deferred income taxes, including current portion	(8,484)
Other intangible liabilities	57,219	57,219
Other intangible liabilities	0
Other non-current liabilities	219,940	207,654
Other non-current liabilities	12,286
Total liabilities	1,115,906	1,086,439
Total liabilities	29,467
Goodwill	124,353	95,624
Goodwill	28,729
Allocation of purchase price	688,534	$ 688,534
Allocation of purchase price	$ 0

Mergers and Acquisitions - Inta

Mergers and Acquisitions - Intangible Assets Acquired (Details) - Alpha Companies $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Business Acquisition [Line Items]
Total acquired intangibles	$ 101,185
Total acquired intangibles, weighted-average amortization period	10 years 1 month 28 days
Mining permits
Business Acquisition [Line Items]
Total acquired intangible assets	$ 157,555
Total acquired intangible assets, weighted-average amortization period	12 years 3 months 18 days
Coal supply agreements, net
Business Acquisition [Line Items]
Total acquired intangible assets	$ 849
Total acquired intangible assets, weighted-average amortization period	1 year 11 days
Coal supply agreements, net
Business Acquisition [Line Items]
Below-market coal supply agreements	$ (57,219)
Below-market coal supply agreements, weighted-average amortization period	2 years 1 month 6 days

Mergers and Acquisitions - Pro

Mergers and Acquisitions - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Combinations [Abstract]
Total revenues, As reported	$ 525,864	$ 447,871	$ 1,791,184	$ 1,459,121
Total revenues, Pro forma		633,656		1,972,610
Income from continuing operations, As reported	$ (43,561)	14,011	$ (11,271)	146,953
Income from continuing operations, Pro forma		$ 2,801		$ 182,533
Basic income per common share, As reported (in dollars per share)	$ (2.29)	$ 1.45	$ (0.59)	$ 15.30
Basic income per common share, Pro forma (in dollars per share)		0.15		9.62
Diluted income per common share, As reported (in dollars per share)	$ (2.29)	1.35	$ (0.59)	14.23
Diluted income per common share, Pro forma (in dollars per share)		$ 0.14		$ 9.26
Weighted average shares - basic (in shares)	19,025,462	9,633,164	19,014,974	9,602,860
Weighted average shares - basic, Pro forma (in shares)		19,011,363		18,981,059
Weighted average shares - diluted, As reported (in shares)	19,025,462	10,384,513	19,014,974	10,328,031
Weighted average shares - diluted, Pro forma (in shares)		19,762,712		19,706,230

Discontinued Operations - Narra

Discontinued Operations - Narrative (Details) - USD ($) $ in Thousands	Aug. 29, 2019	Aug. 06, 2019	Sep. 30, 2019	Dec. 31, 2018
Guarantor Obligations [Line Items]
Performance guarantee issued to company				$ 26,000
Reclamation-related obligations
Guarantor Obligations [Line Items]
Guarantees			$ 570,365
Backstop obligation
Guarantor Obligations [Line Items]
Guarantees				44,800
Letter of credit
Guarantor Obligations [Line Items]
Guarantees				$ 18,800
PRB Transaction | Discontinued Operations, Disposed of by Sale | Reclamation-related obligations
Guarantor Obligations [Line Items]
Guarantees			$ 227,410
Eagle Butte and Belle Ayr Mines | Blackjewel and Other Relevant Parties
Guarantor Obligations [Line Items]
Purchase of mines		$ 33,750
Deposit for purchase of mines		$ 8,100
Pax Surface Mine | Blackjewel and Other Relevant Parties
Guarantor Obligations [Line Items]
Purchase of mines	$ 6,150
Deposit for purchase of mines	$ 5,050

Discontinued Operations - Major

Discontinued Operations - Major Components of Net Income (Loss) (Details) - PRB Transaction - Discontinued Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Total revenues	$ 4	$ 139	$ 152	$ 1,254
Costs and expenses:
Depreciation, depletion and amortization	0	0	145,913	0
Accretion on asset retirement obligations	4,981	0	4,981	0
Asset impairment	694	0	17,162	0
Selling, general and administrative expenses	4,666	12	4,673	39
Other expenses	1,032	1,078	3,964	3,453
Other non-major expense (income) items, net	$ 147	$ 1,166	$ 432	$ 2,092

Discontinued Operations - Maj_2

Discontinued Operations - Major Components of Asset and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Trade accounts payable, accrued expenses and other current liabilities (1)
Asset retirement obligations	$ 151,902
PRB Transaction | Discontinued Operations
Assets:
Prepaid expenses and other current assets	3,401	$ 22,475
Trade accounts payable, accrued expenses and other current liabilities (1)
Trade accounts payable, accrued expenses and other current liabilities	20,439	21,892
Asset retirement obligations	151,902	0
Other non-current liabilities	$ 96	$ 94

Discontinued Operations - Maj_3

Discontinued Operations - Major Components of Cash Flows (Details) - PRB Transaction - Discontinued Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Depreciation, depletion and amortization	$ 0	$ 0	$ 145,913	$ 0
Accretion on asset retirement obligations	$ 4,981	$ 0	$ 4,981	$ 0

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 523,987	$ 443,005	$ 1,784,775	$ 1,446,538
Coal
Disaggregation of Revenue [Line Items]
Revenues	523,987	443,005	1,784,775	1,446,538
Met
Disaggregation of Revenue [Line Items]
Revenues	385,774	387,041	1,357,847	1,277,164
Thermal
Disaggregation of Revenue [Line Items]
Revenues	138,213	55,964	426,928	169,374
Export coal revenues
Disaggregation of Revenue [Line Items]
Revenues	261,815	384,597	967,959	1,267,642
Export coal revenues | Coal
Disaggregation of Revenue [Line Items]
Revenues	261,815	384,597	967,959	1,267,642
Export coal revenues | Met
Disaggregation of Revenue [Line Items]
Revenues	248,628	371,749	928,390	1,239,008
Export coal revenues | Thermal
Disaggregation of Revenue [Line Items]
Revenues	13,187	12,848	39,569	28,634
Domestic coal revenues | Coal
Disaggregation of Revenue [Line Items]
Revenues	262,172	58,408	816,816	178,896
Domestic coal revenues | Met
Disaggregation of Revenue [Line Items]
Revenues	137,146	15,292	429,457	38,156
Domestic coal revenues | Thermal
Disaggregation of Revenue [Line Items]
Revenues	$ 125,026	$ 43,116	$ 387,359	$ 140,740

Revenue - Performance Obligatio

Revenue - Performance Obligations (Details) $ in Thousands	Sep. 30, 2019USD ($)
Revenue from Contract with Customer [Abstract]
Estimated coal revenues	$ 933,148
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue from Contract with Customer [Abstract]
Estimated coal revenues	$ 64,916
Disaggregation of Revenue [Line Items]
Revenue, remaining performance obligation, period	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue from Contract with Customer [Abstract]
Estimated coal revenues	$ 357,281
Disaggregation of Revenue [Line Items]
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue from Contract with Customer [Abstract]
Estimated coal revenues	$ 196,240
Disaggregation of Revenue [Line Items]
Revenue, remaining performance obligation, period	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue from Contract with Customer [Abstract]
Estimated coal revenues	$ 138,444
Disaggregation of Revenue [Line Items]
Revenue, remaining performance obligation, period	3 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue from Contract with Customer [Abstract]
Estimated coal revenues	$ 130,267
Disaggregation of Revenue [Line Items]
Revenue, remaining performance obligation, period	4 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue from Contract with Customer [Abstract]
Estimated coal revenues	$ 46,000
Disaggregation of Revenue [Line Items]
Revenue, remaining performance obligation, period	5 years

Revenue - Contract Balances (De

Revenue - Contract Balances (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Contract asset	$ 985	$ 950

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Contract asset balance recognized within revenues	$ 240,000	$ 0	$ 757,000	$ 0

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive (Loss) Income - Changes to Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 1,071,140	$ 92,648
Ending balance	868,938	239,212
Employee benefit costs
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(23,130)	(1,948)
Other comprehensive income (loss) before reclassifications	458	(128)
Amounts reclassified from accumulated other comprehensive (loss) income	532	117
Ending balance	$ (22,140)	$ (1,959)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive (Loss) Income - Summary of Amounts Reclassified (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Employee benefit costs:
Miscellaneous loss, net	$ (1,523)			$ (154)			$ (2,912)	$ (737)
Income tax benefit (expense)	3,102			(12)			8,880	(133)
Net (loss) income	(68,532)	$ (113,661)	$ 6,815	11,894	$ 73,788	$ 56,941	(175,378)	142,623
Amounts reclassified from accumulated other comprehensive (loss) income | Employee benefit costs
Employee benefit costs:
Miscellaneous loss, net	258			39			719	117
Income tax benefit (expense)	(67)			0			(187)	0
Net (loss) income	$ 191			$ 39			$ 532	$ 117

Net (Loss) Income Per Share - N

Net (Loss) Income Per Share - Narrative (Details) - shares	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Stock options or other stock-based instruments
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0
Stock option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)		86,347

Net (Loss) Income Per Share - S

Net (Loss) Income Per Share - Schedule of Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Net (loss) income
(Loss) income from continuing operations	$ (43,561)			$ 14,011			$ (11,271)	$ 146,953
Loss from discontinued operations	(24,971)			(2,117)			(164,107)	(4,330)
Net (loss) income	$ (68,532)	$ (113,661)	$ 6,815	$ 11,894	$ 73,788	$ 56,941	$ (175,378)	$ 142,623
Basic
Weighted average common shares outstanding - basic (in shares)	19,025,462			9,633,164			19,014,974	9,602,860
Basic (loss) income per common share:
(Loss) income from continuing operations (in dollars per share)	$ (2.29)			$ 1.45			$ (0.59)	$ 15.30
Loss from discontinued operations (in dollars per share)	(1.31)			(0.22)			(8.63)	(0.45)
Net (loss) income (in dollars per share)	$ (3.60)			$ 1.23			$ (9.22)	$ 14.85
Diluted
Weighted average common shares outstanding - basic (in shares)	19,025,462			9,633,164			19,014,974	9,602,860
Diluted effect of warrants (in shares)	0			304,243			0	270,611
Weighted average common shares outstanding - diluted (in shares)	19,025,462			10,384,513			19,014,974	10,328,031
Diluted (loss) income per common share:
(Loss) income from continuing operations (in dollars per share)	$ (2.29)			$ 1.35			$ (0.59)	$ 14.23
Loss from discontinuing operations (in dollars per share)	(1.31)			(0.20)			(8.63)	(0.42)
Net (loss) income (in dollars per share)	$ (3.60)			$ 1.15			$ (9.22)	$ 13.81
Diluted effect of stock options
Diluted
Dilutive effect of share-based payment awards (in shares)	0			260,653			0	265,794
Diluted effect of restricted share units, restricted stock shares and performance-based restricted share units
Diluted
Dilutive effect of share-based payment awards (in shares)	0			186,453			0	188,766

Inventories, Net (Details)

Inventories, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Inventory [Line Items]
Total inventories, net	$ 172,591	$ 121,965
Coal
Inventory [Line Items]
Raw coal	31,924	33,607
Saleable coal	115,290	63,767
Materials, supplies and other, net
Inventory [Line Items]
Materials, supplies and other, net	$ 25,377	$ 24,591

Goodwill and Acquired Intangi_3

Goodwill and Acquired Intangibles (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Assets	$ 138,725	$ 154,584
Liabilities	(8,978)	(33,912)
Net Total	129,747	120,672
Coal supply agreements, net
Finite-Lived Intangible Assets [Line Items]
Assets	2,450	4,687
Mining permits
Finite-Lived Intangible Assets [Line Items]
Assets	136,275	149,897
Coal supply agreements, net
Finite-Lived Intangible Assets [Line Items]
Liabilities	(8,978)	(33,912)
Mining permits
Finite-Lived Intangible Assets [Line Items]
Liabilities	0	0
Coal supply agreements, net
Finite-Lived Intangible Assets [Line Items]
Net Total	(6,528)	(29,225)
Mining permits
Finite-Lived Intangible Assets [Line Items]
Net Total	$ 136,275	$ 149,897

Goodwill and Acquired Intangi_4

Goodwill and Acquired Intangibles - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangibles, net	$ 2,314	$ 1,158	$ (4,712)	$ 12,468
Acquired mine permits, net
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	6,266		17,871
Coal supply agreements, net
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	1,473	1,158	2,351	12,468
Coal supply agreements, net
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible liabilities	5,425	0	24,934	0
Coal supply agreements, net
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangibles, net	$ 3,952	$ 1,158	$ 22,583	$ 12,468

Leases - Right-of-use Assets an

Leases - Right-of-use Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
Assets
Financing lease assets	$ 10,779	$ 9,786
Operating lease right-of-use assets	9,325	11,845
Total lease assets	20,104	21,631
Liabilities
Financing lease liabilities - current	3,146	2,110
Operating lease liabilities - current	2,079	3,624
Financing lease liabilities - long-term	5,206	4,313
Operating lease liabilities - long-term	7,246	8,221
Total lease liabilities	$ 17,677	$ 18,268

Leases - Lease Costs and Other

Leases - Lease Costs and Other Information (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)
Finance lease cost:
Amortization of leased assets	$ 1,143,000	$ 2,796,000
Interest on lease liabilities	108,000	366,000
Operating lease cost	732,000	2,062,000
Short-term lease cost	494,000	1,474,000
Total lease cost	$ 2,477,000	6,698,000
Variable lease income		0
Sublease income		0
Other information
Cash paid for amounts included in the measurement of lease liabilities		6,862,000
Operating cash flows from finance leases		366,000
Operating cash flows from operating leases		3,536,000
Financing cash flows from finance leases		2,960,000
Right-of-use assets obtained in exchange for new finance lease liabilities		$ 1,142,000
Lease Term and Discount Rate
Weighted-average remaining lease term in months - finance leases	2 years 8 months 24 days	2 years 8 months 24 days
Weighted-average remaining lease term in months - operating leases	7 years 10 months 18 days	7 years 10 months 18 days
Weighted-average discount rate - finance leases	5.20%	5.20%
Weighted-average discount rate - operating leases	10.90%	10.90%

Leases - Maturities of Lease Li

Leases - Maturities of Lease Liabilities (Details) $ in Thousands	Sep. 30, 2019USD ($)
Finance Leases
Remainder of 2019	$ 884
2020	3,500
2021	2,864
2022	1,607
2023	97
Thereafter	0
Total future minimum lease payments	8,952
Imputed interest	(600)
Present value of future minimum lease payments	8,352
Operating Leases
Remainder of 2019	785
2020	2,580
2021	1,961
2022	1,654
2023	1,193
Thereafter	6,283
Total future minimum lease payments	14,456
Imputed interest	(5,131)
Present value of future minimum lease payments	$ 9,325

Stock Repurchases (Details)

Stock Repurchases (Details) - USD ($)	Sep. 12, 2019	Sep. 30, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Mar. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Shares repurchased, net			$ 32,464,000	$ 703,000	$ 4,171,000	$ 4,835,000
Common Stock | Capital Return Program
Equity, Class of Treasury Stock [Line Items]
Authorized share repurchases				$ 250,000,000
Common Stock | Company Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Authorized share repurchases		$ 100,000,000	$ 100,000,000
Shares repurchased (in shares)		529,303
Shares repurchased, net		$ 15,969,000
Shares repurchased, gross		15,953,000
Fees related to stock repurchase		$ 16,000
Share repurchase price (in USD per share)		$ 30.17
Shareholders | Common Stock | Stockholders Common Stock Repurchase Agreement
Equity, Class of Treasury Stock [Line Items]
Shares repurchased (in shares)	500,000
Shares repurchased, net	$ 16,495,000
Share repurchase price (in USD per share)	$ 32.99

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Debt discount and issuance costs	$ (32,947)	$ (44,758)
Total long-term debt	592,828	588,012
Less current portion	(28,982)	(42,743)
Long-term debt, net of current portion	563,846	545,269
Term Loan Credit Facility | Term Loan Credit Facility - due November 2025
Debt Instrument [Line Items]
Long-term debt, gross	0	550,000
Term Loan Credit Facility | Term Loan Credit Facility - due June 2024
Debt Instrument [Line Items]
Long-term debt, gross	560,395	0
Total long-term debt	538,395	521,667
Note Payable | LCC Note Payable
Debt Instrument [Line Items]
Long-term debt, gross	45,000	62,500
Note Payable | LCC Water Treatment Obligation
Debt Instrument [Line Items]
Long-term debt, gross	10,625	11,875
Other
Debt Instrument [Line Items]
Long-term debt, gross	$ 9,755	$ 8,395

Long-Term Debt - Narrative (Det

Long-Term Debt - Narrative (Details) - USD ($)	Jun. 14, 2019	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term debt		$ 592,828,000		$ 588,012,000
Current portion of long-term debt		28,982,000		42,743,000
Finance leases		8,352,000
Capital leases				6,423,000
Finance leases - current		3,146,000	$ 2,110,000
Capital leases - current				2,110,000
Term Loan Credit Facility | Term Loan Credit Facility - due June 2024
Debt Instrument [Line Items]
Aggregate amount of debt	$ 561,800,000
Principal payments due in March, June, September and December	1,405,000
Long-term debt		538,395,000		521,667,000
Current portion of long-term debt		5,618,000		20,625,000
Repayments of debt	543,125,000
Loss on modification of debt	255,000
Loss on modification and extinguishment of debt	$ 26,204,000
Term Loan Credit Facility | Term Loan Credit Facility - due June 2024 | Eurocurrency
Debt Instrument [Line Items]
Variable interest rate	7.00%
Interest rate at period end	9.03%
Note Payable | LCC Note Payable
Debt Instrument [Line Items]
Current portion of long-term debt		17,500,000		17,500,000
Outstanding borrowings		$ 36,483,000		49,361,000
Stated interest rate		0.00%
Imputed interest rate		12.45%
Note Payable | LCC Water Treatment Obligation
Debt Instrument [Line Items]
Current portion of long-term debt		$ 2,500,000		1,875,000
Outstanding borrowings		$ 8,196,000		$ 8,589,000
Stated interest rate		0.00%
Imputed interest rate		13.12%
Revolving Credit Facility | Line of Credit | Asset-Based Revolving Credit Facility
Debt Instrument [Line Items]
Outstanding borrowings		$ 0
Letters of credit outstanding		$ 48,634,000
Interest Rate Period One | Term Loan Credit Facility | Term Loan Credit Facility - due June 2024 | Base Rate
Debt Instrument [Line Items]
Variable interest rate	6.00%
Interest Rate Period One | Term Loan Credit Facility | Term Loan Credit Facility - due June 2024 | Eurocurrency
Debt Instrument [Line Items]
Variable interest rate	7.00%
Interest Rate Period Two | Term Loan Credit Facility | Term Loan Credit Facility - due June 2024 | Eurocurrency | Minimum
Debt Instrument [Line Items]
Variable interest rate	7.00%
Interest Rate Period Two | Term Loan Credit Facility | Term Loan Credit Facility - due June 2024 | Eurocurrency | Maximum
Debt Instrument [Line Items]
Variable interest rate	8.00%

Acquisition-Related Obligatio_3

Acquisition-Related Obligations (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Option, Quantitative Disclosures [Line Items]
Discount	$ (5,990)	$ (10,356)
Total acquisition-related obligations - long-term	85,018	100,330
Less current portion	(33,165)	(27,334)
Acquisition-related obligations, net of current portion	51,853	72,996
Contingent Revenue Obligation
Fair Value, Option, Quantitative Disclosures [Line Items]
Total acquisition-related obligations - long-term, gross	55,703	59,880
Total acquisition-related obligations - long-term	55,703	59,880
Less current portion	(14,764)	(9,459)
Environmental Settlement Obligations
Fair Value, Option, Quantitative Disclosures [Line Items]
Total acquisition-related obligations - long-term, gross	16,305	19,306
Discount	(3,137)	(4,538)
Total acquisition-related obligations - long-term	13,168	14,768
Less current portion	(5,124)	(3,375)
Reclamation Funding Liability
Fair Value, Option, Quantitative Disclosures [Line Items]
Total acquisition-related obligations - long-term, gross	12,000	22,000
Discount	(1,679)	(3,894)
Total acquisition-related obligations - long-term	10,321	18,106
Less current portion	(10,321)	(10,000)
Retiree Committee VEBA Funding Settlement Liability
Fair Value, Option, Quantitative Disclosures [Line Items]
Total acquisition-related obligations - long-term, gross	1,000	3,500
UMWA Funds Settlement Liability
Fair Value, Option, Quantitative Disclosures [Line Items]
Total acquisition-related obligations - long-term, gross	$ 6,000	$ 6,000

Acquisition-Related Obligatio_4

Acquisition-Related Obligations - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Business Acquisition, Contingent Consideration [Line Items]
Acquisition related obligations		$ 85,018	$ 100,330
Acquisition related obligations, current		33,165	27,334
Discount		5,990	10,356
Contingent Revenue Obligation
Business Acquisition, Contingent Consideration [Line Items]
Acquisition related obligations		55,703	59,880
Acquisition related obligations, current		14,764	9,459
Payments for acquisition-related obligations	$ 9,627
Environmental Settlement Obligations
Business Acquisition, Contingent Consideration [Line Items]
Acquisition related obligations		13,168	14,768
Acquisition related obligations, current		5,124	3,375
Discount		3,137	4,538
Reclamation Funding Liability
Business Acquisition, Contingent Consideration [Line Items]
Acquisition related obligations		10,321	18,106
Acquisition related obligations, current		10,321	10,000
Discount		$ 1,679	$ 3,894

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Total asset retirement obligations at December 31, 2018	$ 228,448
Measurement-period adjustments	12,718
Accretion for the period	19,911
Sites added during the period	5,113
Revisions in estimated cash flows	(43)
Expenditures for the period	(18,626)
Total asset retirement obligations at September 30, 2019	247,521
Less current portion	(24,365)
Long-term portion	223,156	$ 203,694
Asset retirement obligations	$ 151,902

Fair Value of Financial Instr_3

Fair Value of Financial Instruments and Fair Value Measurements - Summary of Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	$ 583,074	$ 579,617
Carrying Amount | Term Loan Agreement | Term Loan Credit Facility - due June 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	538,395
Carrying Amount | Term Loan Agreement | Term Loan Credit Facility - due November 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt		521,667
Carrying Amount | Note Payable | LCC Note Payable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	36,483	49,361
Carrying Amount | Note Payable | LCC Water Treatment Obligation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	8,196	8,589
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	44,801	59,433
Fair Value, Measurements, Nonrecurring | Total Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	591,187	599,808
Fair Value, Measurements, Nonrecurring | Total Fair Value | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	546,386	540,375
Fair Value, Measurements, Nonrecurring | Total Fair Value | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Term Loan Agreement | Term Loan Credit Facility - due June 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	546,386
Fair Value, Measurements, Nonrecurring | Total Fair Value | Term Loan Agreement | Term Loan Credit Facility - due June 2024 | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	546,386
Fair Value, Measurements, Nonrecurring | Total Fair Value | Term Loan Agreement | Term Loan Credit Facility - due June 2024 | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Term Loan Agreement | Term Loan Credit Facility - due June 2024 | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Term Loan Agreement | Term Loan Credit Facility - due November 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt		540,375
Fair Value, Measurements, Nonrecurring | Total Fair Value | Term Loan Agreement | Term Loan Credit Facility - due November 2025 | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt		540,375
Fair Value, Measurements, Nonrecurring | Total Fair Value | Term Loan Agreement | Term Loan Credit Facility - due November 2025 | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt		0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Term Loan Agreement | Term Loan Credit Facility - due November 2025 | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt		0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Note Payable | LCC Note Payable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	36,517	50,606
Fair Value, Measurements, Nonrecurring | Total Fair Value | Note Payable | LCC Note Payable | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Note Payable | LCC Note Payable | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Note Payable | LCC Note Payable | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	36,517	50,606
Fair Value, Measurements, Nonrecurring | Total Fair Value | Note Payable | LCC Water Treatment Obligation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	8,284	8,827
Fair Value, Measurements, Nonrecurring | Total Fair Value | Note Payable | LCC Water Treatment Obligation | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Note Payable | LCC Water Treatment Obligation | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Note Payable | LCC Water Treatment Obligation | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total long term debt	$ 8,284	$ 8,827

Fair Value of Financial Instr_4

Fair Value of Financial Instruments and Fair Value Measurements - Acquisition-related Obligations at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	$ 29,315	$ 40,450
Carrying Amount | Retiree Committee VEBA Funding Settlement Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	956	3,337
Carrying Amount | UMWA Funds Settlement Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	4,870	4,239
Carrying Amount | Reclamation Funding Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	10,321	18,106
Carrying Amount | Environmental Settlement Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	13,168	14,768
Fair Value, Measurements, Nonrecurring | Total Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	30,105	42,418
Fair Value, Measurements, Nonrecurring | Total Fair Value | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	30,105	42,418
Fair Value, Measurements, Nonrecurring | Total Fair Value | Retiree Committee VEBA Funding Settlement Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	969	3,391
Fair Value, Measurements, Nonrecurring | Total Fair Value | Retiree Committee VEBA Funding Settlement Liability | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Retiree Committee VEBA Funding Settlement Liability | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Retiree Committee VEBA Funding Settlement Liability | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	969	3,391
Fair Value, Measurements, Nonrecurring | Total Fair Value | UMWA Funds Settlement Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	5,134	4,729
Fair Value, Measurements, Nonrecurring | Total Fair Value | UMWA Funds Settlement Liability | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | UMWA Funds Settlement Liability | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | UMWA Funds Settlement Liability | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	5,134	4,729
Fair Value, Measurements, Nonrecurring | Total Fair Value | Reclamation Funding Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	10,814	19,362
Fair Value, Measurements, Nonrecurring | Total Fair Value | Reclamation Funding Liability | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Reclamation Funding Liability | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Reclamation Funding Liability | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	10,814	19,362
Fair Value, Measurements, Nonrecurring | Total Fair Value | Environmental Settlement Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	13,188	14,936
Fair Value, Measurements, Nonrecurring | Total Fair Value | Environmental Settlement Obligations | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Environmental Settlement Obligations | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value | Environmental Settlement Obligations | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Fair Value	$ 13,188	$ 14,936

Fair Value of Financial Instr_5

Fair Value of Financial Instruments and Fair Value Measurements - Schedule of Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Contingent Revenue Obligation	$ 55,703	$ 59,880
Trading securities	27,356
Quoted Prices in Active Markets (Level 1)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Contingent Revenue Obligation	0	0
Trading securities	1,624
Significant Other Observable Inputs (Level 2)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Contingent Revenue Obligation	0	0
Trading securities	25,732
Significant Unobservable Inputs (Level 3)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Contingent Revenue Obligation	55,703	$ 59,880
Trading securities	$ 0

Fair Value of Financial Instr_6

Fair Value of Financial Instruments and Fair Value Measurements - Level 3 of the Fair Value Hierarchy (Details) - Significant Unobservable Inputs (Level 3) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning balance	$ 59,880
Payments	(9,627)
Measurement Period Adjustments	5,738
Loss Recognized in Earnings	(288)
Transfer In (Out) of Level 3 Fair Value Hierarchy	0
Ending balance	$ 55,703

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax [Line Items]
Income tax benefit (expense)	$ 3,102	$ (12)	$ 8,880	$ (133)
Income (loss) from continuing operations before income taxes	$ (46,663)	$ 14,023	(20,151)	$ 147,086
Increase (decrease) in deferred tax asset valuation allowance			31,984
Continuing Operations
Income Tax [Line Items]
Increase (decrease) in deferred tax asset valuation allowance			1,213
Discontinued Operations
Income Tax [Line Items]
Increase (decrease) in deferred tax asset valuation allowance			$ 30,771

Employee Benefit Plans - Sched

Employee Benefit Plans - Schedule of Components of Net Periodic Benefit Cost (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	$ 6,636,000		$ 19,929,000
Expected return on plan assets	(7,011,000)		(21,032,000)
Amortization of net actuarial loss (gain)	199,000		597,000
Net periodic expense	(176,000)	$ 0	(506,000)	$ 0
Black Lung
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	751,000	194,000	1,558,000	582,000
Interest cost	1,567,000	174,000	3,386,000	521,000
Expected return on plan assets	(17,000)	0	(49,000)	0
Amortization of net actuarial loss (gain)	72,000	50,000	162,000	150,000
Net periodic expense	2,373,000	418,000	5,057,000	1,253,000
Life Insurance Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	106,000	97,000	318,000	291,000
Amortization of net actuarial loss (gain)	(26,000)	(11,000)	(78,000)	(33,000)
Net periodic expense	$ 80,000	$ 86,000	$ 240,000	$ 258,000

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to defined contribution and profit sharing plans	$ 4,158,000	$ 1,661,000	$ 23,461,000	$ 8,647,000
Expense for self-insured medical plan	20,976,000	8,468,000	58,873,000	22,496,000
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic (benefit) expense	$ (176,000)	$ 0	$ (506,000)	$ 0

Related Party Transactions - Na

Related Party Transactions - Narrative (Details) $ in Thousands	Jul. 19, 2019USD ($)
Affiliated Entity | Grant of Put Option with Debtor in Possession Lenders
Related Party Transaction [Line Items]
Related party transaction amount	$ 2,900

Commitments and Contingencies (

Commitments and Contingencies (Details) T in Thousands	Oct. 18, 2019USD ($)	Sep. 30, 2019USD ($)T	Sep. 30, 2018USD ($)T	Sep. 30, 2019USD ($)T	Sep. 30, 2018USD ($)T	Oct. 31, 2018USD ($)
Long-term Purchase Commitment [Line Items]
Coal royalty expense		$ 21,868,000	$ 5,439,000	$ 73,119,000	$ 19,182,000
Income tax receivable		68,774,000		68,774,000
Deferred tax asset		68,774,000		68,774,000
Income tax receivable related to NOL carryback claim		43,770,000		43,770,000
Short-term restricted cash		21,456,000	$ 8,853,000	21,456,000	$ 8,853,000
Term Loan Credit Facility - due November 2025 | Line of Credit | Revolving Credit Facility
Long-term Purchase Commitment [Line Items]
Letters of credit outstanding		48,634,000		48,634,000
ANR, Inc. and Citibank, N.A. Credit Agreement | Line of Credit | Letter of Credit
Long-term Purchase Commitment [Line Items]
Letters of credit outstanding		102,990,000		102,990,000
Credit and Security Agreement | Line of Credit | Revolving Credit Facility
Long-term Purchase Commitment [Line Items]
Letters of credit outstanding		613,000		613,000
Worker's compensation
Long-term Purchase Commitment [Line Items]
Restricted cash		95,724,000		95,724,000
Restricted Investments		3,091,000		3,091,000
Black lung
Long-term Purchase Commitment [Line Items]
Restricted cash		31,231,000		31,231,000
Reclamation-related obligations
Long-term Purchase Commitment [Line Items]
Restricted cash		89,993,000		89,993,000
Restricted Investments		15,558,000		15,558,000
Deposits		11,552,000		11,552,000
Real property collateralized		26,749,000		26,749,000
General liability
Long-term Purchase Commitment [Line Items]
Restricted cash		1,160,000		1,160,000
Financial guarantees
Long-term Purchase Commitment [Line Items]
Restricted cash		2,832,000		2,832,000
Contingent revenue obligation
Long-term Purchase Commitment [Line Items]
Short-term restricted cash		9,557,000		9,557,000
Other operating agreements
Long-term Purchase Commitment [Line Items]
Deposits		1,903,000		1,903,000
Reclamation-related obligations
Long-term Purchase Commitment [Line Items]
Guarantees		570,365,000		570,365,000
Collateral supporting guarantees		117,104,000		117,104,000
Reclamation-related obligations | Discontinued Operations, Disposed of by Sale | PRB Transaction
Long-term Purchase Commitment [Line Items]
Guarantees		227,410,000		227,410,000
Reclamation-related obligations | Discontinued Operations, Disposed of by Sale | Eagle Butte and Belle Ayr Mines
Long-term Purchase Commitment [Line Items]
Collateral supporting guarantees		9,000,000		9,000,000
Blackjewel L.L.C
Long-term Purchase Commitment [Line Items]
Severance taxes invoiced						$ 7,800,000
Coal
Long-term Purchase Commitment [Line Items]
Minimum royalty obligations, 2019		2,124,000		2,124,000
Minimum obligations, 2020		14,656,000		14,656,000
Minimum royalty obligations, 2021		13,725,000		13,725,000
Minimum royalty obligations, 2022		11,830,000		11,830,000
Minimum royalty obligations, 2023		10,810,000		10,810,000
Minimum royalty obligations, after 2023		13,441,000		13,441,000
Shipping
Long-term Purchase Commitment [Line Items]
Minimum obligations, 2020		21,967,000		21,967,000
Coal purchase agreements
Long-term Purchase Commitment [Line Items]
Minimum quantities to be purchased, remainder of fiscal year		98,936,000		98,936,000
Minimum quantities to be purchased, second year		30,466,000		30,466,000
Coal purchase agreements, vendors with historical performance less than 20%
Long-term Purchase Commitment [Line Items]
Minimum quantities to be purchased, remainder of fiscal year		29,181,000		29,181,000
Equipment purchase agreements
Long-term Purchase Commitment [Line Items]
Minimum quantities to be purchased, remainder of fiscal year		26,638,000		26,638,000
Minimum quantities to be purchased, second year		11,014,000		11,014,000
Minimum quantities to be purchased, third year		279,000		279,000
Back-to-Back Coal Supply Agreements
Long-term Purchase Commitment [Line Items]
Minimum quantities to be purchased and sold, 2019		6,823,000		6,823,000
Minimum quantities to be purchased and sold, second year		$ 9,175,000		$ 9,175,000
Purchased and sold, tons | T		14	877	735	5,527
Purchased and sold		$ 148,000	$ 9,785,000	$ 7,890,000	$ 60,124,000
Eagle Specialty Materials, LLC | Subsequent Event
Long-term Purchase Commitment [Line Items]
Back taxes paid	$ 13,500,000
Eagle Specialty Materials, LLC | Subsequent Event | Reclamation-related obligations
Long-term Purchase Commitment [Line Items]
Guarantees	0
Collateral supporting guarantees	$ 9,000,000
Blackjewel and Other Relevant Parties
Long-term Purchase Commitment [Line Items]
Deposits		$ 3,050,000		$ 3,050,000

Segment Information - Schedule

Segment Information - Schedule of Operating Results and Capital Expenditures (Details) $ in Thousands	Jun. 30, 2019segment	Nov. 08, 2018segment	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)segmentplantmine	Sep. 30, 2018USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	4	3			3
Total revenues			$ 525,864	$ 447,871	$ 1,791,184	$ 1,459,121
Depreciation, depletion and amortization			60,842	11,141	184,927	33,951
Amortization of acquired intangibles, net			2,314	1,158	(4,712)	12,468
Adjusted EBITDA			40,023	38,806	264,157	223,926
Capital expenditures			60,301	18,373	$ 144,183	56,722
CAPP - Met | Virginia
Segment Reporting Information [Line Items]
Number of active mines | mine					8
Number of preparation plants | plant					2
CAPP - Met | West Virginia
Segment Reporting Information [Line Items]
Number of active mines | mine					17
Number of preparation plants | plant					6
CAPP - Thermal | West Virginia
Segment Reporting Information [Line Items]
Number of active mines | mine					5
Number of preparation plants | plant					3
NAPP | Pennsylvania
Segment Reporting Information [Line Items]
Number of active mines | mine					1
Number of preparation plants | plant					1
Number of closed mines | mine					1
Operating Segments | CAPP - Met
Segment Reporting Information [Line Items]
Total revenues			373,356	378,259	$ 1,340,684	1,240,516
Depreciation, depletion and amortization			38,212	5,658	113,714	17,636
Amortization of acquired intangibles, net			4,765	0	5,816	0
Adjusted EBITDA			58,796	47,897	283,483	235,151
Capital expenditures			47,316	7,984	105,008	23,829
Operating Segments | CAPP - Thermal
Segment Reporting Information [Line Items]
Total revenues			80,432	0	225,698	0
Depreciation, depletion and amortization			13,972	0	44,586	0
Amortization of acquired intangibles, net			(3,359)	0	(12,142)	0
Adjusted EBITDA			1,954	0	8,704	0
Capital expenditures			5,706	0	13,365	0
Operating Segments | NAPP
Segment Reporting Information [Line Items]
Total revenues			71,446	68,950	222,750	215,710
Depreciation, depletion and amortization			6,241	5,298	19,390	15,761
Amortization of acquired intangibles, net			908	1,158	1,614	12,468
Adjusted EBITDA			(4,152)	972	21,900	19,161
Capital expenditures			7,114	10,270	23,317	32,611
All Other
Segment Reporting Information [Line Items]
Total revenues			630	662	2,052	2,895
Depreciation, depletion and amortization			2,417	185	7,237	554
Amortization of acquired intangibles, net			0	0	0	0
Adjusted EBITDA			(16,575)	(10,063)	(49,930)	(30,386)
Capital expenditures			$ 165	$ 119	$ 2,493	$ 282

Segment Information - Reconcili

Segment Information - Reconciliation of Net Income (Loss) to Adjusted EBITDA (Details) - USD ($) $ in Thousands	Apr. 02, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net (loss) income from continuing operations		$ (43,561)	$ 14,011	$ (11,271)	$ 146,953
Interest expense		18,847	8,554	50,079	26,538
Interest income		(1,763)	(507)	(5,584)	(829)
Income tax benefit (expense)		(3,102)	12	(8,880)	133
Depreciation, depletion and amortization		60,842	11,141	184,927	33,951
Merger related costs		68	1,181	1,055	5,064
Management restructuring costs					2,659
Non-cash stock compensation expense		2,738	1,885	7,463	8,240
Mark-to-market adjustment for acquisition-related obligations		(3,238)	0	(288)	0
Gain on settlement of acquisition-related obligations			(118)		(410)
Gain on sale of disposal group					(16,386)
Accretion on asset retirement obligations		6,846	1,489	19,925	5,545
Loss on modification and extinguishment of debt		0	0	26,459	0
Asset impairment		32	0	5,858	0
Cost impact of coal inventory fair value adjustment				8,209
Gain on assets acquired in an exchange transaction				(9,083)	0
Amortization of acquired intangibles, net		2,314	1,158	(4,712)	12,468
Adjusted EBITDA		40,023	38,806	264,157	223,926
Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Gain on assets acquired in an exchange transaction				(9,083)
Operating Segments | CAPP - Met
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net (loss) income from continuing operations		13,033	41,694	154,020	230,898
Interest expense		84	4	306	316
Interest income		(4)	(7)	(12)	(35)
Income tax benefit (expense)		0	0	0	0
Depreciation, depletion and amortization		38,212	5,658	113,714	17,636
Merger related costs		0	0	0	0
Management restructuring costs					0
Non-cash stock compensation expense		348	0	1,127	0
Mark-to-market adjustment for acquisition-related obligations		0		0
Gain on settlement of acquisition-related obligations			0		0
Gain on sale of disposal group					(16,386)
Accretion on asset retirement obligations		2,326	548	6,986	2,722
Loss on modification and extinguishment of debt				0
Asset impairment		32		5,858
Cost impact of coal inventory fair value adjustment				4,751
Gain on assets acquired in an exchange transaction				(9,083)
Amortization of acquired intangibles, net		4,765	0	5,816	0
Adjusted EBITDA		58,796	47,897	283,483	235,151
Operating Segments | CAPP - Thermal
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net (loss) income from continuing operations		(11,338)	0	(34,675)	0
Interest expense		6	0	16	0
Interest income		0	0	0	0
Income tax benefit (expense)		0	0	0	0
Depreciation, depletion and amortization		13,972	0	44,586	0
Merger related costs		0	0	0	0
Management restructuring costs					0
Non-cash stock compensation expense		3	0	60	0
Mark-to-market adjustment for acquisition-related obligations		0		0
Gain on settlement of acquisition-related obligations			0		0
Gain on sale of disposal group					0
Accretion on asset retirement obligations		2,670	0	7,401	0
Loss on modification and extinguishment of debt				0
Asset impairment		0		0
Cost impact of coal inventory fair value adjustment				3,458
Gain on assets acquired in an exchange transaction				0
Amortization of acquired intangibles, net		(3,359)	0	(12,142)	0
Adjusted EBITDA		1,954	0	8,704	0
Operating Segments | NAPP
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net (loss) income from continuing operations		(12,304)	(5,923)	(2,118)	(11,028)
Interest expense		1	(490)	2	(839)
Interest income		(15)	(12)	(38)	(24)
Income tax benefit (expense)		0	0	0	0
Depreciation, depletion and amortization		6,241	5,298	19,390	15,761
Merger related costs		0	0	0	0
Management restructuring costs					0
Non-cash stock compensation expense		0	0	0	0
Mark-to-market adjustment for acquisition-related obligations		0		0
Gain on settlement of acquisition-related obligations			0		0
Gain on sale of disposal group					0
Accretion on asset retirement obligations		1,017	941	3,050	2,823
Loss on modification and extinguishment of debt				0
Asset impairment		0		0
Cost impact of coal inventory fair value adjustment				0
Gain on assets acquired in an exchange transaction				0
Amortization of acquired intangibles, net		908	1,158	1,614	12,468
Adjusted EBITDA		(4,152)	972	21,900	19,161
All Other
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net (loss) income from continuing operations		(32,952)	(21,760)	(128,498)	(72,917)
Interest expense		18,756	9,040	49,755	27,061
Interest income		(1,744)	(488)	(5,534)	(770)
Income tax benefit (expense)		(3,102)	12	(8,880)	133
Depreciation, depletion and amortization		2,417	185	7,237	554
Merger related costs		68	1,181	1,055	5,064
Management restructuring costs					2,659
Non-cash stock compensation expense		2,387	1,885	6,276	8,240
Mark-to-market adjustment for acquisition-related obligations		(3,238)		(288)
Gain on settlement of acquisition-related obligations			(118)		(410)
Gain on sale of disposal group					0
Accretion on asset retirement obligations		833	0	2,488	0
Loss on modification and extinguishment of debt				26,459
Asset impairment		0		0
Cost impact of coal inventory fair value adjustment				0
Gain on assets acquired in an exchange transaction				0
Amortization of acquired intangibles, net		0	0	0	0
Adjusted EBITDA		$ (16,575)	$ (10,063)	$ (49,930)	$ (30,386)
Disposal Group, Disposed of by Sale, Not Discontinued Operations | CAPP-Met Segment Disposal Group | Operating Segments | CAPP - Met
Segment Reporting, Other Significant Reconciling Item [Line Items]
Gain on sale of disposal group	$ (16,386)
Cash paid for disposal	10,000
Expected future cash payment from disposal	$ 1,500

Segment Information - Revenue f

Segment Information - Revenue from External Customers (Details) T in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)customerT	Sep. 30, 2018USD ($)T	Sep. 30, 2019USD ($)customerT	Sep. 30, 2018USD ($)T	Dec. 31, 2018customer
Revenues from External Customers and Long-Lived Assets [Line Items]
Coal revenues	$ 523,987	$ 443,005	$ 1,784,775	$ 1,446,538
Coal purchased from third parties excluding coal sold under Back-to-Back Coal Supply Agreements | T	440	1,705	1,815	4,938
Product Supplied By Third Party Concentration Risk | Coal Purchased From Third Parties Sold
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage	8.00%	44.00%	10.00%	41.00%
Credit Concentration Risk | Accounts Receivable
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of customers | customer	1		1		2
Export coal revenues
Revenues from External Customers and Long-Lived Assets [Line Items]
Coal revenues	$ 261,815	$ 384,597	$ 967,959	$ 1,267,642
Export coal revenues | Geographic Concentration Risk | Revenues
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk percentage	50.00%	87.00%	54.00%	88.00%
India
Revenues from External Customers and Long-Lived Assets [Line Items]
Coal revenues		$ 62,929	$ 228,754	$ 352,344
Turkey
Revenues from External Customers and Long-Lived Assets [Line Items]
Coal revenues		58,402
Brazil
Revenues from External Customers and Long-Lived Assets [Line Items]
Coal revenues		$ 56,519		$ 218,486
Alpha
Revenues from External Customers and Long-Lived Assets [Line Items]
Coal purchased from third parties excluding coal sold under Back-to-Back Coal Supply Agreements | T		1,156		3,451

Subsequent Events (Details)

Subsequent Events (Details) - USD ($)	Oct. 18, 2019	Sep. 30, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Asset retirement obligation		$ 247,521,000	$ 228,448,000
Reclamation-related obligations
Subsequent Event [Line Items]
Guarantees		570,365,000
Collateral supporting guarantees		117,104,000
Backstop obligation
Subsequent Event [Line Items]
Guarantees			44,800,000
Backstop obligation | Subsequent Event
Subsequent Event [Line Items]
Guarantees	$ 44,800,000
Letter of credit
Subsequent Event [Line Items]
Guarantees			$ 18,800,000
Letter of credit | Subsequent Event
Subsequent Event [Line Items]
Guarantees	18,800,000
Eagle Specialty Materials, LLC | Reclamation-related obligations | Subsequent Event
Subsequent Event [Line Items]
Guarantees	238,000,000
Eagle Specialty Materials, LLC | Subsequent Event
Subsequent Event [Line Items]
Payments for transaction	90,000,000
Payment for transaction, paid at closing	81,300,000
Payment for transaction, paid at closing	8,700,000
Purchase deposit waived	3,050,000
Principal and interest paid	3,008,000
Back taxes paid	13,500,000
Eagle Specialty Materials, LLC | Reclamation-related obligations | Subsequent Event
Subsequent Event [Line Items]
Guarantees	0
Collateral supporting guarantees	$ 9,000,000
Eagle Butte and Belle Ayr Mines
Subsequent Event [Line Items]
Asset retirement obligation		$ 151,902,000