Arch Resources (ARCH) 10-Q 24 Jul 19 2019 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 22, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	1-13105
Entity Registrant Name	Arch Coal Inc
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	43-0921172
Entity Address, Address Line One	One CityPlace Drive
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	St. Louis
Entity Address, State or Province	MO
Entity Address, Postal Zip Code	63141
City Area Code	314
Local Phone Number	994-2700
Title of 12(b) Security	Common stock, $.01 par value
Trading Symbol	ARCH
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Bankruptcy Proceedings, Reporting Current	true
Entity Common Stock, Shares Outstanding		16,262,045
Entity Central Index Key	0001037676
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2

Condensed Consolidated Income S

Condensed Consolidated Income Statements - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Revenues	$ 570,222	$ 592,349	$ 1,125,405	$ 1,167,644
Costs, expenses and other operating
Cost of sales (exclusive of items shown separately below)	451,088	474,388	889,559	929,168
Depreciation, depletion and amortization	26,524	30,549	51,797	60,252
Accretion on asset retirement obligations	5,137	6,993	10,274	13,985
Amortization of sales contracts, net	11	3,248	76	6,299
Change in fair value of coal derivatives and coal trading activities, net	(8,400)	15,138	(21,381)	11,724
Selling, general and administrative expenses	25,209	24,756	49,298	50,704
Costs related to proposed joint venture with Peabody Energy	3,018	0	3,018	0
Loss on sale of Lone Mountain Processing, LLC	(4,304)	0	(4,304)	0
Other operating income, net	(3,239)	(7,318)	(4,889)	(14,250)
Costs, expenses and other operating	503,652	547,754	982,056	1,057,882
Income from operations	66,570	44,595	143,349	109,762
Interest expense, net
Interest expense	(4,375)	(5,050)	(8,807)	(10,445)
Interest and investment income	2,088	1,552	4,231	2,825
Interest expense, net	(2,287)	(3,498)	(4,576)	(7,620)
Income before nonoperating expenses	64,283	41,097	138,773	102,142
Nonoperating (expenses) income
Non-service related pension and postretirement benefit (costs) credits	(1,336)	68	(3,102)	(1,235)
Net loss resulting from early retirement of debt and debt restructuring	0	(485)	0	(485)
Reorganization items, net	(16)	(740)	71	(1,041)
Nonoperating expenses	(1,352)	(1,157)	(3,031)	(2,761)
Income before income taxes	62,931	39,940	135,742	99,381
Provision for (benefit from) income taxes	91	(3,366)	161	(3,910)
Net income	$ 62,840	$ 43,306	$ 135,581	$ 103,291
Net income per common share
Basic earnings per common share (in dollars per share)	$ 3.80	$ 2.15	$ 7.97	$ 5.03
Diluted earnings per common share (in dollars per share)	$ 3.53	$ 2.06	$ 7.45	$ 4.81
Weighted average shares outstanding
Basic weighted average shares outstanding (in shares)	16,543	20,156	17,018	20,529
Diluted weighted average shares outstanding (in shares)	17,781	21,036	18,190	21,456
Dividends declared per common share (in dollars per share)	$ 0.45	$ 0.40	$ 0.90	$ 0.80

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net income	$ 62,840	$ 43,306	$ 135,581	$ 103,291
Derivative instruments
Comprehensive income (loss) before tax	(2,778)	(12,293)	(61)	(5,736)
Income tax benefit (provision)	0	0	0	0
Other comprehensive income (loss), derivative instruments, net of tax	(2,778)	(12,293)	(61)	(5,736)
Pension, postretirement and other post-employment benefits
Comprehensive income (loss) before tax	2,902	3,653	2,902	3,653
Income tax benefit (provision)	0	0	0	0
Other comprehensive income (loss), pension, postretirement and other post-employment benefits, net of tax	2,902	3,653	2,902	3,653
Available-for-sale securities
Comprehensive income (loss) before tax	274	177	651	(481)
Income tax benefit (provision)	0	0	0	0
Other comprehensive income (loss), available-for-sale securities, net of tax	274	177	651	(481)
Total other comprehensive income (loss)	398	(8,463)	3,492	(2,564)
Total comprehensive income	$ 63,238	$ 34,843	$ 139,073	$ 100,727

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 232,429	$ 264,937
Short term investments	162,656	162,797
Trade accounts receivable	182,824	200,904
Other receivables	32,950	48,926
Inventories	172,841	125,470
Other current assets	56,993	75,749
Total current assets	840,693	878,783
Property, plant and equipment, net	870,889	834,828
Other assets
Equity investments	106,072	104,676
Other noncurrent assets	71,876	68,773
Total other assets	177,948	173,449
Total assets	1,889,530	1,887,060
Current Liabilities
Accounts payable	138,735	128,024
Accrued expenses and other current liabilities	162,741	183,514
Current maturities of debt	13,068	17,797
Total current liabilities	314,544	329,335
Long-term debt	295,263	300,186
Asset retirement obligations	236,317	230,304
Accrued pension benefits	11,649	16,147
Accrued postretirement benefits other than pension	79,992	83,163
Accrued workers’ compensation	173,621	174,303
Other noncurrent liabilities	80,194	48,801
Total liabilities	1,191,580	1,182,239
Stockholders' equity
Common stock, $0.01 par value, authorized 300,000 shares, issued 25,047 shares at June 30, 2019 and December 31, 2018, respectively	250	250
Paid-in capital	728,996	717,492
Retained earnings	647,440	527,666
Treasury stock, 8,785 shares and 7,216 shares at June 30, 2019 and December 31, 2018, respectively, at cost	(725,524)	(583,883)
Accumulated other comprehensive income	46,788	43,296
Total stockholders’ equity	697,950	704,821
Total liabilities and stockholders’ equity	$ 1,889,530	$ 1,887,060

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	25,047,000	25,047,000
Treasury stock, shares (in shares)	8,785,000	7,216,000

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating activities
Net income	$ 135,581	$ 103,291
Adjustments to reconcile to cash provided by operating activities:
Depreciation, depletion and amortization	51,797	60,252
Accretion on asset retirement obligations	10,274	13,985
Amortization of sales contracts, net	76	6,299
Deferred income taxes	13,385	8,730
Employee stock-based compensation expense	11,473	7,992
(Gains) losses on disposals and divestitures, net	(1,415)	131
Net loss resulting from early retirement of debt and debt restructuring	0	485
Amortization relating to financing activities	1,826	2,170
Changes in:
Receivables	17,871	(20,212)
Inventories	(47,370)	(28,245)
Accounts payable, accrued expenses and other current liabilities	4,497	(11,879)
Income taxes, net	24,575	11,560
Other	3,336	(9,563)
Cash provided by operating activities	225,906	144,996
Investing activities
Capital expenditures	(87,854)	(30,049)
Minimum royalty payments	(1,125)	(124)
Proceeds from disposals and divestitures	1,591	56
Purchases of short term investments	(89,454)	(110,359)
Proceeds from sales of short term investments	90,424	105,150
Investments in and advances to affiliates, net	(3,275)	0
Cash used in investing activities	(89,693)	(35,326)
Financing activities
Payments on term loan due 2024	(1,500)	(1,500)
Net payments on other debt	(8,845)	(7,307)
Debt financing costs	0	(529)
Net loss resulting from early retirement of debt and debt restructuring	0	(50)
Dividends paid	(15,264)	(16,333)
Purchases of treasury stock	(143,142)	(115,973)
Other	30	10
Cash used in financing activities	(168,721)	(141,682)
Decrease in cash and cash equivalents, including restricted cash	(32,508)	(32,012)
Cash and cash equivalents, including restricted cash, beginning of period	264,937	273,602
Cash and cash equivalents, including restricted cash, end of period	232,429	241,590
Cash and cash equivalents, including restricted cash, end of period
Cash and cash equivalents, including restricted cash, end of period	$ 264,937	$ 273,602

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Paid-in Capital	Retained Earnings	Treasury Stock, at cost	Accumulated Other Comprehensive Income
Beginning Balance at Dec. 31, 2017	$ 665,865	$ 250	$ 700,125	$ 247,232	$ (302,109)	$ 20,367
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common shares	(8,553)			(8,553)
Total comprehensive income	65,884			59,985		5,899
Employee stock-based compensation	3,845		3,845
Purchase of common stock under share repurchase program	(38,589)				(38,589)
Warrants exercised	10		10
Ending Balance at Mar. 31, 2018	688,462	250	703,980	298,664	(340,698)	26,266
Beginning Balance at Dec. 31, 2017	665,865	250	700,125	247,232	(302,109)	20,367
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income	100,727
Ending Balance at Jun. 30, 2018	640,948	250	708,127	333,753	(418,985)	17,803
Beginning Balance at Mar. 31, 2018	688,462	250	703,980	298,664	(340,698)	26,266
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common shares	(8,217)			(8,217)
Total comprehensive income	34,843			43,306		(8,463)
Employee stock-based compensation	4,147		4,147
Purchase of common stock under share repurchase program	(78,287)				(78,287)
Ending Balance at Jun. 30, 2018	640,948	250	708,127	333,753	(418,985)	17,803
Beginning Balance at Dec. 31, 2018	704,821	250	717,492	527,666	(583,883)	43,296
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common shares	(8,111)			(8,111)
Total comprehensive income	75,835			72,741		3,094
Employee stock-based compensation	5,651		5,651
Purchase of common stock under share repurchase program	(78,249)				(78,249)
Ending Balance at Mar. 31, 2019	699,947	250	723,143	592,296	(662,132)	46,390
Beginning Balance at Dec. 31, 2018	704,821	250	717,492	527,666	(583,883)	43,296
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income	139,073
Ending Balance at Jun. 30, 2019	697,950	250	728,996	647,440	(725,524)	46,788
Beginning Balance at Mar. 31, 2019	699,947	250	723,143	592,296	(662,132)	46,390
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common shares	(7,696)			(7,696)
Total comprehensive income	63,238			62,840		398
Employee stock-based compensation	5,822		5,822
Purchase of common stock under share repurchase program	(63,392)				(63,392)
Warrants exercised	31		31
Ending Balance at Jun. 30, 2019	$ 697,950	$ 250	$ 728,996	$ 647,440	$ (725,524)	$ 46,788

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity (Deficit) (Parenthetical) - $ / shares shares in Thousands	3 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018
Statement of Stockholders' Equity [Abstract]
Dividends declared per common share (in dollars per share)	$ 0.45	$ 0.45	$ 0.40	$ 0.40
Purchase of shares of common stock under share repurchase program (in shares)	697,255	872,317	960,105	407,091

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of Arch Coal, Inc. (“Arch Coal”) and its subsidiaries (the “Company”). Unless the context indicates otherwise, the terms “Arch” and the “Company” are used interchangeably in this Quarterly Report on Form 10-Q. The Company’s primary business is the production of thermal and metallurgical coal from surface and underground mines located throughout the United States, for sale to utility, industrial and steel producers both in the United States and around the world. The Company currently operates mining complexes in West Virginia, Illinois, Wyoming and Colorado. All subsidiaries are wholly-owned. Intercompany transactions and accounts have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial reporting and U.S. Securities and Exchange Commission regulations. In the opinion of management, all adjustments, consisting of normal, recurring accruals considered necessary for a fair presentation, have been included. Results of operations for the three and six months ended June 30, 2019 are not necessarily indicative of results to be expected for the year ending December 31, 2019 . These financial statements should be read in conjunction with the audited financial statements and related notes as of and for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission.

Accounting Policies

Accounting Policies	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Accounting Policies	Accounting Policies Recently Adopted Accounting Guidance In February 2016, the FASB established Topic 842, Leases, by issuing ASU No. 2016-02, “Leases” which requires lessees to recognize leases on-balance sheet and disclose key information about leasing arrangements. The ASU was subsequently amended by ASU 2018-01, “Land Easements Practical Expedient for Transition to Topic 842;” ASU 2018-10, “Codification Improvements to Topic 842, Leases;” and ASU 2018-11, “Targeted Improvements.” The new standard establishes a right-of-use (“ROU”) model that requires a lessee to recognize an ROU asset and lease liability on the balance sheet for all leases with a term longer than 12 months. The standard also requires a lessee to recognize a single lease cost, calculated so that the cost of the lease is allocated over the term of the lease, on a generally straight line basis. Leases of mineral reserves and related land leases have been exempted from the standard. 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 “package of practical expedients” 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 made an election to not separate lease and non-lease components for all leases, and will not use hindsight. Finally, the Company will continue its current policy for accounting for land easements as executory contracts. The adoption of the standard had no impact on the Company’s consolidated income statement or statement of cash flows. In April 2017, the FASB issued ASU No. 2017-08, “Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities.” The new guidance shortens the amortization period for the premium on certain purchased callable debt securities to the earliest call date. The new guidance does not change the accounting for purchased callable debt securities held at a discount. The Company adopted ASU 2017-08 effective January 1, 2019 with no impact on the Company’s financial statements. In August 2017, the FASB issued ASU No. 2017-12, “Targeted Improvements to Accounting for Hedging Activities.” The new guidance provides targeted improvements to the accounting for hedging activities to better align an entity’s risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedging results. The Company adopted ASU 2017-12 effective January 1, 2019 with no impact on the Company’s financial statements. In February 2018, the FASB issued ASU 2018-02, “Income Statement-Reporting Comprehensive Income (Topic 220) Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” ASU 2018-02 provides an option to reclassify stranded tax effects within accumulated other comprehensive income to retained earnings due to the change in the U.S. federal tax rate in the Tax Cuts and Jobs Act of 2017. The Company adopted ASU 2018-02 effective January 1, 2019 with no impact on the Company’s financial statements. In June 2018, the FASB issued ASU 2018-07, “Compensation-Stock Compensation (Topic 718), Improvements to Non-employee Share-Based Payment Accounting.” ASU 2018-07 aligns the measurement and classification guidance for share-based payments to non-employees with the guidance for share-based payments to employees. The Company adopted ASU 2018-07 effective January 1, 2019 with no impact on the Company’s financial statements. In October 2018, the FASB issued ASU 2018-16, “Derivatives and Hedging (Topic 815), Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate of Hedge Accounting Purposes.” The Company adopted ASU 2018-16 effective January 1, 2019 with no impact on the Company’s financial statements.

Joint Venture with Peabody Ener

Joint Venture with Peabody Energy	6 Months Ended
	Jun. 30, 2019
Equity Method Investments and Joint Ventures [Abstract]
Joint Venture with Peabody Energy	Joint Venture with Peabody Energy On June 18, 2019, Arch Coal, Inc. (“Arch”), entered into a definitive implementation agreement (the “Implementation Agreement”) with Peabody Energy Corporation (“Peabody”), to establish a joint venture that will combine the respective Powder River Basin and Colorado mining operations of Arch and Peabody. Pursuant to the terms of the Implementation Agreement, Arch will hold a 33.5% economic interest, and Peabody will hold a 66.5% economic interest in the joint venture. At the closing, certain of the respective subsidiaries of Arch and Peabody will enter into an Amended and Restated Limited Liability Company Agreement (the “LLC Agreement”) in substantially the form attached as an exhibit to the Implementation Agreement. Under the terms of the LLC Agreement, the governance of the joint venture will be overseen by the joint venture’s board of managers, which will initially be comprised of three representatives appointed by Peabody and two representatives appointed by Arch. Decisions of the board of managers will be determined by a majority vote subject to certain specified matters set forth in the LLC Agreement that will require a supermajority vote. Peabody, or one of its affiliates, will initially be appointed as the operator of the joint venture and will manage the day-to-day operations of the joint venture, subject to the supervision of the joint venture’s board of managers. Formation of the joint venture is subject to customary closing conditions, including the termination or expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, the receipt of certain other required regulatory approvals and the absence of injunctions or other legal restraints preventing the formation of the joint venture. The obligation of Arch to consummate the transaction is also conditioned upon (a) Arch having obtained consents or refinanced all outstanding indebtedness under Arch’s senior secured term loan facility, Arch’s inventory based revolving credit facility and Arch’s existing accounts receivable securitization facility and (b) Arch having either obtained an exemptive order from the U.S. Securities and Exchange Commission (the “SEC”) or other exemptive determination under the Investment Company Act of 1940 (the “1940 Act”). The obligation of Peabody to consummate the transaction is also conditioned upon Peabody having obtained consents or refinanced all outstanding indebtedness under Peabody’s existing senior secured credit facility, the indenture governing Peabody’s 6.000% Notes due 2022 and 6.375% Notes due 2025 and Peabody’s existing receivables securitization facility. Formation of the joint venture does not require approval of the respective stockholders of either Arch or Peabody. The Implementation Agreement contains customary representations, warranties and covenants, including an obligation for each of Arch and Peabody to use its best efforts to take all actions necessary to obtain required regulatory approvals, subject to the limitations set forth in the Implementation Agreement. The Implementation Agreement may be terminated by mutual written agreement of Arch and Peabody and by either Arch or Peabody if, among other things, the closing has not occurred on or prior to December 18, 2020, except that (a) the right to terminate will not be available to a party whose failure to perform any of its obligations under the Implementation Agreement has been a principal cause of or resulted in the failure of the closing to occur on or prior to such date and (b) the right to terminate will not be available to Arch until June 18, 2021 if all closing conditions have been satisfied other than the receipt by Arch of an exemptive order (or other determination) under the 1940 Act. Additionally, if the closing has not occurred on or prior to June 18, 2020 and all required regulatory approvals have not been obtained, the Implementation Agreement may be terminated by either Arch or Peabody no later than June 29, 2020 following written notice and the payment by the terminating party to the non-terminating party of a termination fee of $40 million ; provided, however, that the non-terminating party may elect to extend the Implementation Agreement until September 18, 2020. If the non-terminating party exercises this option to extend, the termination fee payable to the non-terminating party by the terminating party if the closing does not occur on or prior to September 18, 2020 will be reduced to $25 million . Except as set forth above, neither party will be required to pay a termination fee if the Implementation Agreement is terminated. If all closing conditions have been satisfied other than the receipt by Arch of an exemptive order (or other determination) under the 1940 Act, Arch will reimburse Peabody for regulatory transaction expenses.

Loss on Sale of Lone Mountain P

Loss on Sale of Lone Mountain Processing, LLC	6 Months Ended
	Jun. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
Loss on Sale of Lone Mountain Processing, Inc	Loss on Sale of Lone Mountain Processing, LLC On September 14, 2017, the Company sold Lone Mountain Processing, LLC and two idled mining companies, Cumberland River Coal LLC and Powell Mountain Energy LLC to Revelation Energy LLC, add recorded a gain on the transaction in that year of $21.3 million . Under the terms of the purchase agreement, Revelation assumed certain traumatic workers compensation claims and pneumoconiosis (occupational disease) benefits. On July 1, 2019, Blackjewel LLC and four affiliates, including Revelation Energy LLC filed for Chapter 11 bankruptcy. As a result of the bankruptcy, the Company has recorded a $4.3 million charge for these claims.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	6 Months Ended
	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income The following items are included in accumulated other comprehensive income (“AOCI”): Pension, Postretirement and Other Accumulated Post- Other Derivative Employment Available-for- Comprehensive Instruments Benefits Sale Securities Income (In thousands) Balance at December 31, 2018 $ 3,328 $ 40,311 $ (343 ) $ 43,296 Unrealized gains 3,072 3,331 666 7,069 Amounts reclassified from AOCI (3,133 ) (429 ) (15 ) (3,577 ) Balance at June 30, 2019 $ 3,267 $ 43,213 $ 308 $ 46,788 The following amounts were reclassified out of AOCI: Three Months Ended June 30, Six Months Ended June 30, Details About AOCI Components 2019 2018 2019 2018 Line Item in the Condensed Consolidated Statement of Operations (In thousands) Coal hedges $ 1,743 $ — $ 2,104 $ — Revenues Interest rate hedges 514 348 1,029 488 Interest expense — — — — Provision for (benefit from) income taxes $ 2,257 $ 348 $ 3,133 $ 488 Net of tax Pension, postretirement and other post-employment benefits Pension settlement 429 1,371 429 1,371 Non-service related pension and postretirement benefit (costs) credits — — — — Provision for (benefit from) income taxes $ 429 $ 1,371 $ 429 $ 1,371 Net of tax Available-for-sale securities $ 15 $ 16 $ 15 $ 16 Interest and investment income — — — — Provision for (benefit from) income taxes $ 15 $ 16 $ 15 $ 16 Net of tax

Inventories

Inventories	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consist of the following: June 30, December 31, 2019 2018 (In thousands) Coal $ 83,432 $ 40,982 Repair parts and supplies 89,409 84,488 $ 172,841 $ 125,470 The repair parts and supplies are stated net of an allowance for slow-moving and obsolete inventories of $1.4 million at June 30, 2019 and $0.6 million at December 31, 2018 .

Investments in Available-for-Sa

Investments in Available-for-Sale Securities	6 Months Ended
	Jun. 30, 2019
Debt Securities, Available-for-sale [Abstract]
Investments in Available-for-Sale Securities	Investments in Available-for-Sale Securities The Company has invested in marketable debt securities, primarily highly liquid U.S. Treasury securities and investment grade corporate bonds. These investments are held in the custody of a major financial institution. These securities are classified as available-for-sale securities and, accordingly, the unrealized gains and losses are recorded through other comprehensive income. The Company’s investments in available-for-sale marketable securities are as follows: June 30, 2019 Balance Sheet Classification Gross Unrealized Fair Short-Term Other Cost Basis Gains Losses Value Investments Assets (In thousands) Available-for-sale: U.S. government and agency securities $ 58,283 $ 94 $ — $ 58,377 $ 58,377 $ — Corporate notes and bonds 104,066 247 (34 ) 104,279 104,279 — Total Investments $ 162,349 $ 341 $ (34 ) $ 162,656 $ 162,656 $ — December 31, 2018 Balance Sheet Classification Gross Unrealized Fair Short-Term Other Cost Basis Gains Losses Value Investments Assets (In thousands) Available-for-sale: U.S. government and agency securities $ 100,003 $ 11 $ (126 ) $ 99,888 $ 99,888 $ — Corporate notes and bonds 63,137 4 (232 ) 62,909 62,909 — Total Investments $ 163,140 $ 15 $ (358 ) $ 162,797 $ 162,797 $ — The aggregate fair value of investments with unrealized losses that were owned for less than a year was $25.2 million and $115.2 million at June 30, 2019 and December 31, 2018 , respectively. The aggregate fair value of investments with unrealized losses that were owned for over a year was $0.0 million and $32.4 million at June 30, 2019 and December 31, 2018 , respectively. The unrealized losses in the Company’s portfolio at June 30, 2019 are the result of normal market fluctuations. The Company does not currently intend to sell these investments before recovery of their amortized cost base. The debt securities outstanding at June 30, 2019 have maturity dates ranging from the third quarter of 2019 through the fourth quarter of 2020 . The Company classifies its investments as current based on the nature of the investments and their availability to provide cash for use in current operations.

Derivatives

Derivatives	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives Interest rate risk management The Company has entered into interest rate swaps to reduce the variability of cash outflows associated with interest payments on its variable rate term loan. These swaps have been designated as cash flow hedges. For additional information on these arrangements, see Note 10 , “ Debt and Financing Arrangements ,” in the Condensed Consolidated Financial Statements. Diesel fuel price risk management The Company is exposed to price risk with respect to diesel fuel purchased for use in its operations. The Company anticipates purchasing approximately 40 to 47 million gallons of diesel fuel for use in its operations annually. To protect the Company’s cash flows from increases in the price of diesel fuel for its operations, the Company uses forward physical diesel purchase contracts, purchased heating oil call options and New York Mercantile Exchange (“NYMEX”) gulf coast diesel swaps and options. At June 30, 2019 , the Company had protected the price on the majority of its expected diesel fuel purchases for the remainder of 2019 with approximately 10 million gallons of heating oil call options with an average strike price of $2.34 per gallon and 12 million gallons of NYMEX gulf coast diesel swaps at an average price of approximately $1.91 per gallon. Additionally, the Company has protected approximately 22% of its expected 2020 purchases using gulf coast diesel call options with an average strike price of $2.30 per gallon. At June 30, 2019 , the Company had outstanding heating oil call options and NYMEX gulf coast swaps and options of approximately 32 million gallons for the purpose of managing the price risk associated with future diesel purchases. These positions are not designated as hedges for accounting purposes, and therefore, changes in the fair value are recorded immediately to earnings. Coal price risk management positions The Company may sell or purchase forward contracts, swaps and options in the over-the-counter coal market in order to manage its exposure to coal prices. The Company has exposure to the risk of fluctuating coal prices related to forecasted, index-priced sales or purchases of coal or to the risk of changes in the fair value of a fixed price physical sales contract. Certain derivative contracts may be designated as hedges of these risks. At June 30, 2019 , the Company held derivatives for risk management purposes that are expected to settle in the following years: (Tons in thousands) 2019 2020 Total Coal sales 1,540 489 2,029 Coal purchases 772 225 997 The Company has also entered into a minimal quantity of natural gas put options to protect the Company from decreases in natural gas prices, which could impact thermal coal demand. These options are not designated as hedges. Coal trading positions The Company may sell or purchase forward contracts, swaps and options in the over-the-counter coal market for trading purposes. The Company is exposed to the risk of changes in coal prices on the value of its coal trading portfolio. The estimated future realization of the value of the trading portfolio is $0.6 million of losses during the remainder of 2019 and $0.5 million of losses during 2020 . Tabular derivatives disclosures The Company has master netting agreements with all of its counterparties which allow for the settlement of contracts in an asset position with contracts in a liability position in the event of default or termination. Such netting arrangements reduce the Company’s credit exposure related to these counterparties. For classification purposes, the Company records the net fair value of all the positions with a given counterparty as a net asset or liability in the Condensed Consolidated Balance Sheets. The amounts shown in the table below represent the fair value position of individual contracts, and not the net position presented in the accompanying Condensed Consolidated Balance Sheets. The fair value and location of derivatives reflected in the accompanying Condensed Consolidated Balance Sheets are as follows: June 30, 2019 December 31, 2018 Fair Value of Derivatives Asset Liability Asset Liability (In thousands) Derivative Derivative Derivative Derivative Derivatives Designated as Hedging Instruments Coal $ 7,728 $ (637 ) $ 2,342 $ (805 ) Derivatives Not Designated as Hedging Instruments Heating oil -- diesel purchases 923 (650 ) 532 — Coal -- held for trading purposes 45,685 (46,807 ) 10,329 (10,701 ) Coal -- risk management 33,804 (25,150 ) 5,672 (19,579 ) Natural gas — — 4 (4 ) Total $ 80,412 $ (72,607 ) $ 16,537 $ (30,284 ) Total derivatives $ 88,140 $ (73,244 ) $ 18,879 $ (31,089 ) Effect of counterparty netting (72,594 ) 72,594 (17,801 ) 17,801 Net derivatives as classified in the balance sheets $ 15,546 $ (650 ) $ 14,896 $ 1,078 $ (13,288 ) $ (12,210 ) June 30, 2019 December 31, 2018 Net derivatives as reflected on the balance sheets (in thousands) Heating oil and coal Other current assets $ 15,546 $ 1,078 Coal Accrued expenses and other current liabilities (650 ) (13,288 ) $ 14,896 $ (12,210 ) The Company had a current asset representing cash collateral posted to a margin account for derivative positions primarily related to coal derivatives of $2.1 million and $24.7 million at June 30, 2019 and December 31, 2018 , respectively. These amounts are not included with the derivatives presented in the table above and are included in “other current assets” in the accompanying Condensed Consolidated Balance Sheets. The effects of derivatives on measures of financial performance are as follows: Derivatives used in Cash Flow Hedging Relationships (in thousands) Three Months Ended June 30, Gain (Loss) Recognized in Other Comprehensive Income Gains (Losses) Reclassified from Other Comprehensive Income into Income 2019 2018 2019 2018 Coal sales (1) $ 4,010 $ (15,462 ) $ 1,743 $ — Coal purchases (2) (340 ) 2,705 — — Totals $ 3,670 $ (12,757 ) $ 1,743 $ — No ineffectiveness or amounts excluded from effectiveness testing relating to the Company’s cash flow hedging relationships were recognized in the results of operations in the three month periods ended June 30, 2019 and 2018 . Derivatives Not Designated as Hedging Instruments (in thousands) Three Months Ended June 30, Gain (Loss) Recognized 2019 2018 Coal trading — realized and unrealized (3) $ (718 ) $ 384 Coal risk management — unrealized (3) 9,137 (15,505 ) Natural gas trading— realized and unrealized (3) (19 ) (17 ) Change in fair value of coal derivatives and coal trading activities, net total $ 8,400 $ (15,138 ) Coal risk management— realized (4) $ (881 ) $ (1,649 ) Heating oil — diesel purchases (4) $ (1,369 ) $ 3,657 ____________________________________________________________ Location in statement of operations: (1) — Revenues (2) — Cost of sales (3) — Change in fair value of coal derivatives and coal trading activities, net (4) — Other operating (income) expense, net Derivatives used in Cash Flow Hedging Relationships (in thousands) Six Months Ended June 30, Gain (Loss) Recognized in Other Comprehensive Income Gains (Losses) Reclassified from Other Comprehensive Income into Income 2019 2018 2019 2018 Coal sales (1) $ 9,247 $ (10,231 ) $ 2,787 $ — Coal purchases (2) (906 ) 2,163 (686 ) — Totals $ 8,341 $ (8,068 ) $ 2,101 $ — No ineffectiveness or amounts excluded from effectiveness testing relating to the Company’s cash flow hedging relationships were recognized in the results of operations in the six month periods ended June 30, 2019 and 2018 . Derivatives Not Designated as Hedging Instruments (in thousands) Six Months Ended June 30, Gain (Loss) Recognized 2019 2018 Coal trading — realized and unrealized (3) $ (1,101 ) $ 942 Coal risk management — unrealized (3) 22,562 (12,630 ) Natural gas trading— realized and unrealized (3) (80 ) (36 ) Change in fair value of coal derivatives and coal trading activities, net total $ 21,381 $ (11,724 ) Coal risk management— realized (4) $ (5,292 ) $ (2,680 ) Heating oil — diesel purchases (4) $ (732 ) $ 3,675 ____________________________________________________________ Location in statement of operations: (1) — Revenues (2) — Cost of sales (3) — Change in fair value of coal derivatives and coal trading activities, net (4) — Other operating (income) expense, net Based on fair values at June 30, 2019 , amounts on derivative contracts designated as hedge instruments in cash flow hedges to be reclassified from other comprehensive income into earnings during the next twelve months are gains of approximately $5.9 million

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	6 Months Ended
	Jun. 30, 2019
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following: June 30, December 31, 2019 2018 (In thousands) Payroll and employee benefits $ 49,418 $ 57,166 Taxes other than income taxes 72,502 75,017 Interest 221 156 Acquired sales contracts 319 570 Workers’ compensation 18,108 20,044 Asset retirement obligations 12,297 13,113 Other 9,876 17,448 $ 162,741 $ 183,514

Debt and Financing Arrangements

Debt and Financing Arrangements	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Debt and Financing Arrangements	Debt and Financing Arrangements June 30, December 31, 2019 2018 (In thousands) Term loan due 2024 ($293.3 million face value) $ 292,224 $ 293,626 Other 21,669 30,449 Debt issuance costs (5,562 ) (6,092 ) 308,331 317,983 Less: current maturities of debt 13,068 17,797 Long-term debt $ 295,263 $ 300,186 Term Loan Facility In 2017, the Company entered into a senior secured term loan credit agreement (the “Credit Agreement”) in an aggregate principal amount of $300 million (the “Term Loan Debt Facility”) with Credit Suisse AG, Cayman Islands Branch, as administrative agent and collateral agent, and the other financial institutions from time to time party thereto (collectively, the “Lenders”). The Term Loan Debt Facility was issued at 99.50% of the face amount and will mature on March 7, 2024. The term loans provided under the Term Loan Debt Facility (the “Term Loans”) are subject to quarterly principal amortization payments in an amount equal to $750,000 . During 2018, the Company entered into the Second Amendment (the “Second Amendment”) to its Credit Agreement. The Second Amendment reduced the interest rate on its Term Loan Debt Facility to, at the option of Arch Coal, either (i) the London interbank offered rate (“LIBOR”) plus an applicable margin of 2.75% , subject to a 1.00% LIBOR floor, or (ii) a base rate plus an applicable margin of 1.75% . The LIBOR floor remains at 1.00% . There is no change to the maturities as a result of the Second Amendment. The Term Loan Debt Facility is guaranteed by all existing and future wholly owned domestic subsidiaries of the Company (collectively, the “Subsidiary Guarantors” and, together with Arch Coal, the “Loan Parties”), subject to customary exceptions, and is secured by first priority security interests on substantially all assets of the Loan Parties, including 100% of the voting equity interests of directly owned domestic subsidiaries and 65% of the voting equity interests of directly owned foreign subsidiaries, subject to customary exceptions. The Company has the right to prepay Term Loans at any time, and from time to time, in whole or in part without premium or penalty, upon written notice, except that any prepayment of Term Loans that bear interest at the LIBOR Rate other than at the end of the applicable interest periods therefor shall be made with reimbursement for any funding losses and redeployment costs of the Lenders resulting therefrom. The Term Loan Debt Facility is subject to certain usual and customary mandatory prepayment events, including 100% of net cash proceeds of (i) debt issuances (other than debt permitted to be incurred under the terms of the Term Loan Debt Facility) and (ii) non-ordinary course asset sales or dispositions, subject to customary thresholds, exceptions and reinvestment rights. The Term Loan Debt Facility contains customary affirmative covenants and representations. The Term Loan Debt Facility also contains customary negative covenants, which, among other things, and subject to certain exceptions, include restrictions on (i) indebtedness, (ii) liens, (iii) liquidations, mergers, consolidations and acquisitions, (iv) disposition of assets or subsidiaries, (v) affiliate transactions, (vi) creation or ownership of certain subsidiaries, partnerships and joint ventures, (vii) continuation of or change in business, (viii) restricted payments, (ix) prepayment of subordinated and junior lien indebtedness, (x) restrictions in agreements on dividends, intercompany loans and granting liens on the collateral, (xi) loans and investments, (xii) sale and leaseback transactions, (xiii) changes in organizational documents and fiscal year and (xiv) transactions with respect to bonding subsidiaries. The Term Loan Debt Facility does not contain any financial maintenance covenants. The Term Loan Debt Facility contains customary events of default, subject to customary thresholds and exceptions, including, among other things, (i) nonpayment of principal and nonpayment of interest and fees, (ii) a material inaccuracy of a representation or warranty at the time made, (iii) a failure to comply with any covenant, subject to customary grace periods in the case of certain affirmative covenants, (iv) cross-events of default to indebtedness of at least $50 million , (v) cross-events of default to surety, reclamation or similar bonds securing obligations with an aggregate face amount of at least $50 million , (vi) uninsured judgments in excess of $50 million , (vii) any loan document shall cease to be a legal, valid and binding agreement, (viii) uninsured losses or proceedings against assets with a value in excess of $50 million , (ix) certain ERISA events, (x) a change of control or (xi) bankruptcy or insolvency proceedings relating to the Company or any material subsidiary of the Company. Accounts Receivable Securitization Facility In 2018, the Company extended and amended its existing trade accounts receivable securitization facility provided to Arch Receivable Company, LLC, a special-purpose entity that is a wholly owned subsidiary of Arch Coal (“Arch Receivable”) (the “Extended Securitization Facility”), which supports the issuance of letters of credit and requests for cash advances. The amendment to the Extended Securitization Facility maintained the $160 million borrowing capacity and extended the maturity date to the date that is three years after the Securitization Facility Closing Date. Additionally, the amendment provided the Company the opportunity to use credit insurance to increase the pool of eligible receivables for borrowing. Pursuant to the Extended Securitization Facility, Arch Receivable also agreed to a revised schedule of fees payable to the administrator and the providers of the Extended Securitization Facility. The Extended Securitization Facility will terminate at the earliest of (i) three years from the Securitization Facility Closing Date, (ii) if the Liquidity (defined in the Extended Securitization Facility and consistent with the definition in the Inventory Facility) is less than $175 million for a period of 60 consecutive days, the date that is the 364 th day after the first day of such 60 consecutive day period, and (iii) the occurrence of certain predefined events substantially consistent with the existing transaction documents. Under the Extended Securitization Facility, Arch Receivable, Arch Coal and certain of Arch Coal’s subsidiaries party to the Extended Securitization Facility have granted to the administrator of the Extended Securitization Facility a first priority security interest in eligible trade accounts receivable generated by such parties from the sale of coal and all proceeds thereof. As of June 30, 2019 , letters of credit totaling $15.7 million were outstanding under the facility with $86.5 million available for borrowings. Inventory-Based Revolving Credit Facility In 2017, the Company and certain subsidiaries of Arch Coal entered into a senior secured inventory-based revolving credit facility in an aggregate principal amount of $40 million (the “Inventory Facility”) with Regions Bank (“Regions”) as administrative agent and collateral agent, as lender and swingline lender (in such capacities, the “Lender”) and as letter of credit issuer. Availability under the Inventory Facility is subject to a borrowing base consisting of (i) 85% of the net orderly liquidation value of eligible coal inventory, (ii) the lesser of (x) 85% of the net orderly liquidation value of eligible parts and supplies inventory and (y) 35% of the amount determined pursuant to clause (i), and (iii) 100% of Arch Coal’s Eligible Cash (defined in the Inventory Facility), subject to reduction for reserves imposed by Regions. In 2018, the Company and certain subsidiaries of Arch Coal amended and extended the Inventory Facility by increasing the facility size by $10 million , bringing the total aggregate amount available to $50 million , subject to borrowing base calculations described above. The commitments under the Inventory Facility will terminate on the date that is the earliest to occur of (i) the date, if any, that is 364 days following the first day that Liquidity (defined in the Inventory Facility and consistent with the definition in the Extended Securitization Facility (as defined below)) is less than $250 million for a period of 60 consecutive days and (ii) the date, if any, that is 60 days following the maturity, termination or repayment in full of the Extended Securitization Facility. Revolving loan borrowings under the Inventory Facility bear interest at a per annum rate equal to, at the option of Arch Coal, either the base rate or the London interbank offered rate plus, in each case, a margin ranging from 2.00% to 2.50% (in the case of LIBOR loans) and 1.00% to 1.50% (in the case of base rate loans) determined using a Liquidity-based grid. Letters of credit under the Inventory Facility are subject to a fee in an amount equal to the applicable margin for LIBOR loans, plus customary fronting and issuance fees. All existing and future direct and indirect domestic subsidiaries of Arch Coal, subject to customary exceptions, will either constitute co-borrowers under or guarantors of the Inventory Facility (collectively with Arch Coal, the “Loan Parties”). The Inventory Facility is secured by first priority security interests in the ABL Priority Collateral (defined in the Inventory Facility) of the Loan Parties and second priority security interests in substantially all other assets of the Loan Parties, subject to customary exceptions (including an exception for the collateral that secures the Extended Securitization Facility). Arch Coal has the right to prepay borrowings under the Inventory Facility at any time and from time to time in whole or in part without premium or penalty, upon written notice, except that any prepayment of such borrowings that bear interest at the LIBOR rate other than at the end of the applicable interest periods therefore shall be made with reimbursement for any funding losses and redeployment costs of the Lender resulting therefrom. The Inventory Facility is subject to certain usual and customary mandatory prepayment events, including non-ordinary course asset sales or dispositions, subject to customary thresholds, exceptions (including exceptions for required prepayments under Arch Coal’s term loan facility) and reinvestment rights. The Inventory Facility contains certain customary affirmative and negative covenants; events of default, subject to customary thresholds and exceptions; and representations, including certain cash management and reporting requirements that are customary for asset-based credit facilities. The Inventory Facility also includes a requirement to maintain Liquidity equal to or exceeding $175 million at all times. As of June 30, 2019 , letters of credit totaling $35.6 million were outstanding under the facility with $14.4 million available for borrowings. Interest Rate Swaps The Company has entered into a series of interest rate swaps to fix a portion of the LIBOR interest rate within the term loan. The interest rate swaps qualify for cash flow hedge accounting treatment and as such, the change in the fair value of the interest rate swaps is recorded on the Company’s Condensed Consolidated Balance Sheet as an asset or liability with the effective portion of the gains or losses reported as a component of accumulated other comprehensive income and the ineffective portion reported in earnings. As interest payments are made on the term loan, amounts in accumulated other comprehensive income will be reclassified into earnings through interest expense to reflect a net interest on the term loan equal to the effective yield of the fixed rate of the swap plus 2.75% which is the spread on the revised LIBOR term loan. In the event that an interest rate swap is terminated prior to maturity, gains or losses in accumulated other comprehensive income will remain deferred and be reclassified into earnings in the periods which the hedged forecasted transaction affects earnings. Below is a summary of the Company’s outstanding interest rate swap agreements designated as hedges as of June 30, 2019 : Notional Amount (in millions) Effective Date Fixed Rate Receive Rate Expiration Date $250.0 June 28, 2019 2.025% 1-month LIBOR June 30, 2020 $200.0 June 30, 2020 2.249% 1-month LIBOR June 30, 2021 $100.0 June 30, 2021 2.315% 1-month LIBOR June 30, 2023 The fair value of the interest rate swaps at June 30, 2019 is a liability of $2.6 million which is recorded within Other noncurrent liabilities with the offset to accumulated other comprehensive income on the Company’s Condensed Consolidated Balance Sheet. The Company realized $0.5 million and $1.0 million of gains during the three and six months ended June 30, 2019 related to settlements of the interest rate swaps which was recorded to interest expense on the Company’s Condensed Consolidated Income Statements. The interest rate swaps are classified as level 2 within the fair value hierarchy.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes A reconciliation of the statutory federal income tax provision at the statutory rate to the actual provision for (benefit from) income taxes follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 (In thousands) Income tax provision at statutory rate $ 13,216 $ 8,387 $ 28,506 $ 20,870 Percentage depletion allowance (3,457 ) (2,488 ) (7,764 ) (7,095 ) State taxes, net of effect of federal taxes 831 583 1,843 1,337 Change in valuation allowance (11,292 ) (7,317 ) (23,805 ) (17,956 ) Current expense associated with uncertain tax positions 844 792 1,437 2,181 Other, net (51 ) (3,323 ) (56 ) (3,247 ) Provision for (benefit from) income taxes $ 91 $ (3,366 ) $ 161 $ (3,910 )

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The hierarchy of fair value measurements assigns a level to fair value measurements based on the inputs used in the respective valuation techniques. The levels of the hierarchy, as defined below, give the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. · Level 1 is defined as observable inputs such as quoted prices in active markets for identical assets. Level 1 assets include U.S. Treasury securities, and coal swaps and futures that are submitted for clearing on the New York Mercantile Exchange. · Level 2 is defined as observable inputs other than Level 1 prices. These include quoted prices for similar assets or liabilities in an active market, quoted prices for identical assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. The Company’s level 2 assets and liabilities include U.S. government agency securities, coal commodity contracts and interest rate swaps with fair values derived from quoted prices in over-the-counter markets or from prices received from direct broker quotes. · Level 3 is defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. These include the Company’s commodity option contracts (coal, natural gas and heating oil) valued using modeling techniques, such as Black-Scholes, that require the use of inputs, particularly volatility, that are rarely observable. Changes in the unobservable inputs would not have a significant impact on the reported Level 3 fair values at June 30, 2019 . The table below sets forth, by level, the Company’s financial assets and liabilities that are recorded at fair value in the accompanying Condensed Consolidated Balance Sheet: June 30, 2019 Total Level 1 Level 2 Level 3 (In thousands) Assets: Investments in marketable securities $ 162,656 $ 58,377 $ 104,279 $ — Derivatives 15,378 13,883 740 755 Total assets $ 178,034 $ 72,260 $ 105,019 $ 755 Liabilities: Derivatives $ 3,048 $ — $ 3,048 $ — The Company’s contracts with its counterparties allow for the settlement of contracts in an asset position with contracts in a liability position in the event of default or termination. For classification purposes, the Company records the net fair value of all the positions with these counterparties as a net asset or liability. Each level in the table above displays the underlying contracts according to their classification in the accompanying Condensed Consolidated Balance Sheet, based on this counterparty netting. The following table summarizes the change in the fair values of financial instruments categorized as Level 3. Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 (In thousands) Balance, beginning of period $ 851 $ 532 Realized and unrealized gains recognized in earnings, net (398 ) (542 ) Purchases 537 1,000 Issuances — — Settlements (235 ) (235 ) Ending balance $ 755 $ 755 Net unrealized losses of $1.4 million and $1.1 million were recognized in the Condensed Consolidated Income Statements within Other operating income, net during the three and six months ended June 30, 2019 , respectively, related to Level 3 financial instruments held on June 30, 2019 . Fair Value of Long-Term Debt At June 30, 2019 and December 31, 2018 , the fair value of the Company’s debt, including amounts classified as current, was $314.6 million and $318.6 million , respectively. Fair values are based upon observed prices in an active market, when available, or from valuation models using market information, which fall into Level 2 in the fair value hierarchy.

Earnings per Common Share

Earnings per Common Share	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Earnings per Common Share	Earnings per Common Share The Company computes basic net income per share using the weighted average number of common shares outstanding during the period. Diluted net income per share is computed using the weighted average number of common shares and the effect of potentially dilutive securities outstanding during the period. Potentially dilutive securities may consist of warrants, restricted stock units or other contingently issuable shares. The dilutive effect of outstanding warrants, restricted stock units and other contingently issuable shares is reflected in diluted earnings per share by application of the treasury stock method. The following table provides the basis for basic and diluted earnings per share by reconciling the denominators of the computations: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 (In thousands) Weighted average shares outstanding: Basic weighted average shares outstanding 16,543 20,156 17,018 20,529 Effect of dilutive securities 1,238 880 1,172 927 Diluted weighted average shares outstanding 17,781 21,036 18,190 21,456

Workers Compensation Expense

Workers Compensation Expense	6 Months Ended
	Jun. 30, 2019
Compensation Related Costs [Abstract]
Workers Compensation Expense	Workers Compensation Expense The Company is liable under the Federal Mine Safety and Health Act of 1969, as subsequently amended, to provide for pneumoconiosis (occupational disease) benefits to eligible employees, former employees and dependents. The Company currently provides for federal claims principally through a self-insurance program. The Company is also liable under various state workers’ compensation statutes for occupational disease benefits. The occupational disease benefit obligation represents the present value of the actuarially computed present and future liabilities for such benefits over the employees’ applicable years of service. In addition, the Company is liable for workers’ compensation benefits for traumatic injuries which are calculated using actuarially-based loss rates, loss development factors and discounted based on a risk free rate. Traumatic workers’ compensation claims are insured with varying retentions/deductibles, or through state-sponsored workers’ compensation programs. Workers’ compensation expense consists of the following components: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 (In thousands) Self-insured occupational disease benefits: Service cost $ 1,669 $ 1,860 $ 3,338 $ 3,720 Interest cost (1) 1,354 1,194 2,708 2,389 Total occupational disease $ 3,023 $ 3,054 $ 6,046 $ 6,109 Traumatic injury claims and assessments 2,410 2,188 4,554 5,199 Total workers’ compensation expense $ 5,433 $ 5,242 $ 10,600 $ 11,308

Employee Benefit Plans

Employee Benefit Plans	6 Months Ended
	Jun. 30, 2019
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Employee Benefit Plans	Employee Benefit Plans The following table details the components of pension benefit costs (credits): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 (In thousands) Interest cost (1) $ 2,259 $ 2,270 $ 4,517 $ 4,541 Expected return on plan assets (1) (2,724 ) (3,080 ) (5,447 ) (6,161 ) Pension settlement (1) (429 ) (1,371 ) (429 ) (1,371 ) Net benefit credit $ (894 ) $ (2,181 ) $ (1,359 ) $ (2,991 ) The following table details the components of other postretirement benefit costs: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 (In thousands) Service cost $ 120 $ 139 $ 240 $ 279 Interest cost (1) 877 919 1,753 1,837 Net benefit cost $ 997 $ 1,058 $ 1,993 $ 2,116

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company accrues for costs related to contingencies when a loss is probable and the amount is reasonably determinable. Disclosure of contingencies is included in the financial statements when it is at least reasonably possible that a material loss or an additional material loss in excess of amounts already accrued may be incurred. In addition, the Company is a party to numerous other claims and lawsuits with respect to various matters. The ultimate resolution of any such legal matter could result in outcomes which may be materially different from amounts the Company has accrued for such matters. The Company believes it has recorded adequate reserves for these matters.

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Segment Information	Segment Information The Company’s reportable business segments are based on two distinct lines of business, metallurgical and thermal, and may include a number of mine complexes. The Company manages its coal sales by market, not by individual mining complex. Geology, coal transportation routes to customers, and regulatory environments also have a significant impact on the Company’s marketing and operations management. Mining operations are evaluated based on Adjusted EBITDA, per-ton cash operating costs (defined as including all mining costs except depreciation, depletion, amortization, accretion on asset retirement obligations, and pass-through transportation expenses), and on other non-financial measures, such as safety and environmental performance. Adjusted EBITDA is not a measure of financial performance in accordance with generally accepted accounting principles, and items excluded from Adjusted EBITDA are significant in understanding and assessing the Company’s financial condition. Therefore, Adjusted EBITDA should not be considered in isolation, nor as an alternative to net income, income from operations, cash flows from operations or as a measure of our profitability, liquidity or performance under generally accepted accounting principles. The Company uses Adjusted EBITDA to measure the operating performance of its segments and allocate resources to the segments. Furthermore, analogous measures are used by industry analysts and investors to evaluate the Company’s operating performance. Investors should be aware that the Company’s presentation of Adjusted EBITDA may not be comparable to similarly titled measures used by other companies. The Company reports its results of operations primarily through the following reportable segments: Powder River Basin (PRB) segment containing the Company’s primary thermal operations in Wyoming; the Metallurgical (MET) segment, containing the Company’s metallurgical operations in West Virginia, and the Other Thermal segment containing the Company’s supplementary thermal operations in Colorado, Illinois, and West Virginia. Operating segment results for the three and six months ended June 30, 2019 and 2018 , are presented below. The Company measures its segments based on “adjusted earnings before interest, taxes, depreciation, depletion, amortization, accretion on asset retirements obligations, and nonoperating expenses (Adjusted EBITDA).” Adjusted EBITDA does not reflect mine closure or impairment costs, since those are not reflected in the operating income reviewed by management. The Corporate, Other and Eliminations grouping includes these charges, as well as the change in fair value of coal derivatives and coal trading activities, net; corporate overhead; land management activities; other support functions; and the elimination of intercompany transactions. PRB MET Other Thermal Corporate, Other and Eliminations Consolidated (in thousands) Three Months Ended June 30, 2019 Revenues $ 210,149 $ 261,245 $ 98,205 $ 623 $ 570,222 Adjusted EBITDA 14,696 101,936 10,922 (21,990 ) 105,564 Depreciation, depletion and amortization 4,880 17,343 3,689 612 26,524 Accretion on asset retirement obligation 3,135 531 603 868 5,137 Total assets 236,527 605,657 136,899 910,447 1,889,530 Capital expenditures 13,209 31,150 3,211 1,138 48,708 Three Months Ended June 30, 2018 Revenues $ 229,878 $ 259,032 $ 99,814 $ 3,625 $ 592,349 Adjusted EBITDA 26,491 86,657 11,842 (39,605 ) 85,385 Depreciation, depletion and amortization 8,304 18,018 3,701 526 30,549 Accretion on asset retirement obligation 4,885 469 565 1,074 6,993 Total assets 379,613 551,012 134,319 884,469 1,949,413 Capital expenditures 3,065 11,899 2,559 3,073 20,596 Six Months Ended June 30, 2019 Revenues $ 422,878 $ 514,507 $ 184,183 $ 3,837 $ 1,125,405 Adjusted EBITDA 35,279 193,470 17,041 (32,972 ) 212,818 Depreciation, depletion and amortization 9,745 33,725 7,124 1,203 51,797 Accretion on asset retirement obligation 6,271 1,061 1,207 1,735 10,274 Total assets 236,527 605,657 136,899 910,447 1,889,530 Capital expenditures 13,623 62,374 9,461 2,396 87,854 Six Months Ended June 30, 2018 Revenues $ 475,306 $ 497,379 $ 191,334 $ 3,625 $ 1,167,644 Adjusted EBITDA 53,993 170,399 27,510 (61,604 ) 190,298 Depreciation, depletion and amortization 16,727 35,003 7,536 986 60,252 Accretion on asset retirement obligation 9,771 937 1,130 2,147 13,985 Total assets 379,613 551,012 134,319 884,469 1,949,413 Capital expenditures 3,763 17,728 3,765 4,793 30,049 A reconciliation of net income to adjusted EBITDA follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 (In thousands) Net income $ 62,840 $ 43,306 $ 135,581 $ 103,291 Provision for (benefit from) income taxes 91 (3,366 ) 161 (3,910 ) Interest expense, net 2,287 3,498 4,576 7,620 Depreciation, depletion and amortization 26,524 30,549 51,797 60,252 Accretion on asset retirement obligations 5,137 6,993 10,274 13,985 Amortization of sales contracts, net 11 3,248 76 6,299 Loss on sale of Lone Mountain Processing, LLC 4,304 — 4,304 — Net loss resulting from early retirement of debt and debt restructuring — 485 — 485 Non-service related pension and postretirement benefit costs 1,336 (68 ) 3,102 1,235 Reorganization items, net 16 740 (71 ) 1,041 Costs associated with proposed joint venture with Peabody Energy 3,018 — 3,018 — Adjusted EBITDA $ 105,564 $ 85,385 $ 212,818 $ 190,298

Revenue Recognition

Revenue Recognition	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition ASC 606-10-50-5 requires that entities disclose disaggregated revenue information in categories (such as type of good or service, geography, market, type of contract, etc.) that depict how the nature, amount, timing, and uncertainty of revenue and cash flow are affected by economic factors. ASC 606-10-55-89 explains that the extent to which an entity’s revenue is disaggregated depends on the facts and circumstances that pertain to the entity’s contracts with customers and that some entities may need to use more than one type of category to meet the objective for disaggregating revenue. In general, the Company’s business segmentation is aligned according to the nature and economic characteristics of its coal and customer relationships and provides meaningful disaggregation of each segment’s results. The company has further disaggregated revenue between North America and Seaborne revenues which depicts the pricing and contract differences between the two. North America revenue is characterized by contracts with a term of one year or longer and typically the pricing is fixed; whereas Seaborne revenue generally is derived by spot or short term contracts with an indexed based pricing mechanism. PRB MET Other Thermal Corporate, Other and Eliminations Consolidated (in thousands) Three Months Ended June 30, 2019 North America revenues $ 210,149 $ 54,896 $ 47,885 $ 623 $ 313,553 Seaborne revenues — 206,349 50,320 — 256,669 Total revenues $ 210,149 $ 261,245 $ 98,205 $ 623 $ 570,222 Three Months Ended June 30, 2018 North America revenues $ 229,035 $ 38,323 $ 40,547 $ 3,625 $ 311,530 Seaborne revenues 843 220,709 59,267 — 280,819 Total revenues $ 229,878 $ 259,032 $ 99,814 $ 3,625 $ 592,349 Six Months Ended June 30, 2019 North America revenues $ 422,878 $ 99,562 $ 94,414 $ 3,837 $ 620,691 Seaborne revenues — 414,945 89,769 — 504,714 Total revenues $ 422,878 $ 514,507 $ 184,183 $ 3,837 $ 1,125,405 Six Months Ended June 30, 2018 North America revenues $ 473,395 $ 68,001 $ 84,214 $ 3,625 $ 629,235 Seaborne revenues 1,911 429,378 107,120 — 538,409 Total revenues $ 475,306 $ 497,379 $ 191,334 $ 3,625 $ 1,167,644 As of June 30, 2019 , the Company has outstanding performance obligations for the remainder of 2019 of 38.9 million tons of fixed price contracts and 4.9 million tons of variable price contracts. Additionally, the Company has outstanding performance obligations beyond 2019 of approximately 64.3 million tons of fixed price contracts and 5.7 million tons of variable price contracts.

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases	Leases The Company has operating leases for mining equipment, office equipment and office space with remaining lease terms ranging from less than 1 year to approximately 8 years . Some of these leases include both lease and non-lease components which are accounted for as a single lease component as the Company has elected the practical expedient to combine these components for all leases. As most of the leases do not provide an implicit rate, the Company calculated the right-of-use assets and lease liabilities using its’ secured incremental borrowing rate at the lease commencement date. The Company currently does not have any finance leases outstanding. Information related to leases was as follows: Three Months Ended June 30, 2019 (In thousands) Operating lease information: Operating lease cost $ 916 Operating cash flows from operating leases 869 Weighted average remaining lease term in years 5.45 Weighted average discount rate 5.5 % Future minimum lease payments under non-cancellable leases as of June 30, 2019 were as follows: Year Amount (In thousands) 2019 $ 2,101 2020 3,616 2021 3,367 2022 3,292 2023 3,261 Thereafter 11,153 Total minimum lease payments $ 26,790 Less imputed interest (5,012 ) Total operating lease liability $ 21,778 As reflected on balance sheet: Accrued expenses and other current liabilities $ 2,909 Other noncurrent liabilities 18,869 Total operating lease liability $ 21,778 At June 30, 2019 , the Company had a $21.1 million right-of-use operating lease asset recorded within “Other noncurrent assets” on the Condensed Consolidated Balance Sheet.

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial reporting and U.S. Securities and Exchange Commission regulations. In the opinion of management, all adjustments, consisting of normal, recurring accruals considered necessary for a fair presentation, have been included. Results of operations for the three and six months ended June 30, 2019 are not necessarily indicative of results to be expected for the year ending December 31, 2019 . These financial statements should be read in conjunction with the audited financial statements and related notes as of and for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission.
Recently Adopted Accounting Guidance	Recently Adopted Accounting Guidance In February 2016, the FASB established Topic 842, Leases, by issuing ASU No. 2016-02, “Leases” which requires lessees to recognize leases on-balance sheet and disclose key information about leasing arrangements. The ASU was subsequently amended by ASU 2018-01, “Land Easements Practical Expedient for Transition to Topic 842;” ASU 2018-10, “Codification Improvements to Topic 842, Leases;” and ASU 2018-11, “Targeted Improvements.” The new standard establishes a right-of-use (“ROU”) model that requires a lessee to recognize an ROU asset and lease liability on the balance sheet for all leases with a term longer than 12 months. The standard also requires a lessee to recognize a single lease cost, calculated so that the cost of the lease is allocated over the term of the lease, on a generally straight line basis. Leases of mineral reserves and related land leases have been exempted from the standard. 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 “package of practical expedients” 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 made an election to not separate lease and non-lease components for all leases, and will not use hindsight. Finally, the Company will continue its current policy for accounting for land easements as executory contracts. The adoption of the standard had no impact on the Company’s consolidated income statement or statement of cash flows. In April 2017, the FASB issued ASU No. 2017-08, “Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities.” The new guidance shortens the amortization period for the premium on certain purchased callable debt securities to the earliest call date. The new guidance does not change the accounting for purchased callable debt securities held at a discount. The Company adopted ASU 2017-08 effective January 1, 2019 with no impact on the Company’s financial statements. In August 2017, the FASB issued ASU No. 2017-12, “Targeted Improvements to Accounting for Hedging Activities.” The new guidance provides targeted improvements to the accounting for hedging activities to better align an entity’s risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedging results. The Company adopted ASU 2017-12 effective January 1, 2019 with no impact on the Company’s financial statements. In February 2018, the FASB issued ASU 2018-02, “Income Statement-Reporting Comprehensive Income (Topic 220) Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” ASU 2018-02 provides an option to reclassify stranded tax effects within accumulated other comprehensive income to retained earnings due to the change in the U.S. federal tax rate in the Tax Cuts and Jobs Act of 2017. The Company adopted ASU 2018-02 effective January 1, 2019 with no impact on the Company’s financial statements. In June 2018, the FASB issued ASU 2018-07, “Compensation-Stock Compensation (Topic 718), Improvements to Non-employee Share-Based Payment Accounting.” ASU 2018-07 aligns the measurement and classification guidance for share-based payments to non-employees with the guidance for share-based payments to employees. The Company adopted ASU 2018-07 effective January 1, 2019 with no impact on the Company’s financial statements. In October 2018, the FASB issued ASU 2018-16, “Derivatives and Hedging (Topic 815), Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate of Hedge Accounting Purposes.” The Company adopted ASU 2018-16 effective January 1, 2019 with no impact on the Company’s financial statements.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following items are included in accumulated other comprehensive income (“AOCI”): Pension, Postretirement and Other Accumulated Post- Other Derivative Employment Available-for- Comprehensive Instruments Benefits Sale Securities Income (In thousands) Balance at December 31, 2018 $ 3,328 $ 40,311 $ (343 ) $ 43,296 Unrealized gains 3,072 3,331 666 7,069 Amounts reclassified from AOCI (3,133 ) (429 ) (15 ) (3,577 ) Balance at June 30, 2019 $ 3,267 $ 43,213 $ 308 $ 46,788
Schedule of Comprehensive Income Reclassifications	The following amounts were reclassified out of AOCI: Three Months Ended June 30, Six Months Ended June 30, Details About AOCI Components 2019 2018 2019 2018 Line Item in the Condensed Consolidated Statement of Operations (In thousands) Coal hedges $ 1,743 $ — $ 2,104 $ — Revenues Interest rate hedges 514 348 1,029 488 Interest expense — — — — Provision for (benefit from) income taxes $ 2,257 $ 348 $ 3,133 $ 488 Net of tax Pension, postretirement and other post-employment benefits Pension settlement 429 1,371 429 1,371 Non-service related pension and postretirement benefit (costs) credits — — — — Provision for (benefit from) income taxes $ 429 $ 1,371 $ 429 $ 1,371 Net of tax Available-for-sale securities $ 15 $ 16 $ 15 $ 16 Interest and investment income — — — — Provision for (benefit from) income taxes $ 15 $ 16 $ 15 $ 16 Net of tax

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Inventories	Inventories consist of the following: June 30, December 31, 2019 2018 (In thousands) Coal $ 83,432 $ 40,982 Repair parts and supplies 89,409 84,488 $ 172,841 $ 125,470

Investments in Available-for-_2

Investments in Available-for-Sale Securities (Tables)	6 Months Ended
	Jun. 30, 2019
Debt Securities, Available-for-sale [Abstract]
Available-for-sale Securities	The Company’s investments in available-for-sale marketable securities are as follows: June 30, 2019 Balance Sheet Classification Gross Unrealized Fair Short-Term Other Cost Basis Gains Losses Value Investments Assets (In thousands) Available-for-sale: U.S. government and agency securities $ 58,283 $ 94 $ — $ 58,377 $ 58,377 $ — Corporate notes and bonds 104,066 247 (34 ) 104,279 104,279 — Total Investments $ 162,349 $ 341 $ (34 ) $ 162,656 $ 162,656 $ — December 31, 2018 Balance Sheet Classification Gross Unrealized Fair Short-Term Other Cost Basis Gains Losses Value Investments Assets (In thousands) Available-for-sale: U.S. government and agency securities $ 100,003 $ 11 $ (126 ) $ 99,888 $ 99,888 $ — Corporate notes and bonds 63,137 4 (232 ) 62,909 62,909 — Total Investments $ 163,140 $ 15 $ (358 ) $ 162,797 $ 162,797 $ —

Derivatives (Tables)

Derivatives (Tables)	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Price Risk Derivatives	At June 30, 2019 , the Company held derivatives for risk management purposes that are expected to settle in the following years: (Tons in thousands) 2019 2020 Total Coal sales 1,540 489 2,029 Coal purchases 772 225 997
Disclosure of Fair Value of Derivatives	The fair value and location of derivatives reflected in the accompanying Condensed Consolidated Balance Sheets are as follows: June 30, 2019 December 31, 2018 Fair Value of Derivatives Asset Liability Asset Liability (In thousands) Derivative Derivative Derivative Derivative Derivatives Designated as Hedging Instruments Coal $ 7,728 $ (637 ) $ 2,342 $ (805 ) Derivatives Not Designated as Hedging Instruments Heating oil -- diesel purchases 923 (650 ) 532 — Coal -- held for trading purposes 45,685 (46,807 ) 10,329 (10,701 ) Coal -- risk management 33,804 (25,150 ) 5,672 (19,579 ) Natural gas — — 4 (4 ) Total $ 80,412 $ (72,607 ) $ 16,537 $ (30,284 ) Total derivatives $ 88,140 $ (73,244 ) $ 18,879 $ (31,089 ) Effect of counterparty netting (72,594 ) 72,594 (17,801 ) 17,801 Net derivatives as classified in the balance sheets $ 15,546 $ (650 ) $ 14,896 $ 1,078 $ (13,288 ) $ (12,210 ) June 30, 2019 December 31, 2018 Net derivatives as reflected on the balance sheets (in thousands) Heating oil and coal Other current assets $ 15,546 $ 1,078 Coal Accrued expenses and other current liabilities (650 ) (13,288 ) $ 14,896 $ (12,210 )
Effects of Derivatives on Measures of Financial Performance	The effects of derivatives on measures of financial performance are as follows: Derivatives used in Cash Flow Hedging Relationships (in thousands) Three Months Ended June 30, Gain (Loss) Recognized in Other Comprehensive Income Gains (Losses) Reclassified from Other Comprehensive Income into Income 2019 2018 2019 2018 Coal sales (1) $ 4,010 $ (15,462 ) $ 1,743 $ — Coal purchases (2) (340 ) 2,705 — — Totals $ 3,670 $ (12,757 ) $ 1,743 $ — Derivatives Not Designated as Hedging Instruments (in thousands) Three Months Ended June 30, Gain (Loss) Recognized 2019 2018 Coal trading — realized and unrealized (3) $ (718 ) $ 384 Coal risk management — unrealized (3) 9,137 (15,505 ) Natural gas trading— realized and unrealized (3) (19 ) (17 ) Change in fair value of coal derivatives and coal trading activities, net total $ 8,400 $ (15,138 ) Coal risk management— realized (4) $ (881 ) $ (1,649 ) Heating oil — diesel purchases (4) $ (1,369 ) $ 3,657 ____________________________________________________________ Location in statement of operations: (1) — Revenues (2) — Cost of sales (3) — Change in fair value of coal derivatives and coal trading activities, net (4) — Other operating (income) expense, net Derivatives used in Cash Flow Hedging Relationships (in thousands) Six Months Ended June 30, Gain (Loss) Recognized in Other Comprehensive Income Gains (Losses) Reclassified from Other Comprehensive Income into Income 2019 2018 2019 2018 Coal sales (1) $ 9,247 $ (10,231 ) $ 2,787 $ — Coal purchases (2) (906 ) 2,163 (686 ) — Totals $ 8,341 $ (8,068 ) $ 2,101 $ — Derivatives Not Designated as Hedging Instruments (in thousands) Six Months Ended June 30, Gain (Loss) Recognized 2019 2018 Coal trading — realized and unrealized (3) $ (1,101 ) $ 942 Coal risk management — unrealized (3) 22,562 (12,630 ) Natural gas trading— realized and unrealized (3) (80 ) (36 ) Change in fair value of coal derivatives and coal trading activities, net total $ 21,381 $ (11,724 ) Coal risk management— realized (4) $ (5,292 ) $ (2,680 ) Heating oil — diesel purchases (4) $ (732 ) $ 3,675 ____________________________________________________________ Location in statement of operations: (1) — Revenues (2) — Cost of sales (3) — Change in fair value of coal derivatives and coal trading activities, net (4) — Other operating (income) expense, net

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	6 Months Ended
	Jun. 30, 2019
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following: June 30, December 31, 2019 2018 (In thousands) Payroll and employee benefits $ 49,418 $ 57,166 Taxes other than income taxes 72,502 75,017 Interest 221 156 Acquired sales contracts 319 570 Workers’ compensation 18,108 20,044 Asset retirement obligations 12,297 13,113 Other 9,876 17,448 $ 162,741 $ 183,514

Debt and Financing Arrangemen_2

Debt and Financing Arrangements (Tables)	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Debt	June 30, December 31, 2019 2018 (In thousands) Term loan due 2024 ($293.3 million face value) $ 292,224 $ 293,626 Other 21,669 30,449 Debt issuance costs (5,562 ) (6,092 ) 308,331 317,983 Less: current maturities of debt 13,068 17,797 Long-term debt $ 295,263 $ 300,186
Schedule of Interest Rate Derivatives	Below is a summary of the Company’s outstanding interest rate swap agreements designated as hedges as of June 30, 2019 : Notional Amount (in millions) Effective Date Fixed Rate Receive Rate Expiration Date $250.0 June 28, 2019 2.025% 1-month LIBOR June 30, 2020 $200.0 June 30, 2020 2.249% 1-month LIBOR June 30, 2021 $100.0 June 30, 2021 2.315% 1-month LIBOR June 30, 2023

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	A reconciliation of the statutory federal income tax provision at the statutory rate to the actual provision for (benefit from) income taxes follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 (In thousands) Income tax provision at statutory rate $ 13,216 $ 8,387 $ 28,506 $ 20,870 Percentage depletion allowance (3,457 ) (2,488 ) (7,764 ) (7,095 ) State taxes, net of effect of federal taxes 831 583 1,843 1,337 Change in valuation allowance (11,292 ) (7,317 ) (23,805 ) (17,956 ) Current expense associated with uncertain tax positions 844 792 1,437 2,181 Other, net (51 ) (3,323 ) (56 ) (3,247 ) Provision for (benefit from) income taxes $ 91 $ (3,366 ) $ 161 $ (3,910 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Summary of Financial Assets and Liabilities Accounted for at Fair Value	The table below sets forth, by level, the Company’s financial assets and liabilities that are recorded at fair value in the accompanying Condensed Consolidated Balance Sheet: June 30, 2019 Total Level 1 Level 2 Level 3 (In thousands) Assets: Investments in marketable securities $ 162,656 $ 58,377 $ 104,279 $ — Derivatives 15,378 13,883 740 755 Total assets $ 178,034 $ 72,260 $ 105,019 $ 755 Liabilities: Derivatives $ 3,048 $ — $ 3,048 $ —
Summary of Change in the Fair Values of Financial Instruments Categorized as Level 3	The following table summarizes the change in the fair values of financial instruments categorized as Level 3. Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 (In thousands) Balance, beginning of period $ 851 $ 532 Realized and unrealized gains recognized in earnings, net (398 ) (542 ) Purchases 537 1,000 Issuances — — Settlements (235 ) (235 ) Ending balance $ 755 $ 755

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Schedule of Weighted Average Number of Shares	The following table provides the basis for basic and diluted earnings per share by reconciling the denominators of the computations: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 (In thousands) Weighted average shares outstanding: Basic weighted average shares outstanding 16,543 20,156 17,018 20,529 Effect of dilutive securities 1,238 880 1,172 927 Diluted weighted average shares outstanding 17,781 21,036 18,190 21,456

Workers Compensation Expense (T

Workers Compensation Expense (Tables)	6 Months Ended
	Jun. 30, 2019
Compensation Related Costs [Abstract]
Workers' compensation expense	Workers’ compensation expense consists of the following components: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 (In thousands) Self-insured occupational disease benefits: Service cost $ 1,669 $ 1,860 $ 3,338 $ 3,720 Interest cost (1) 1,354 1,194 2,708 2,389 Total occupational disease $ 3,023 $ 3,054 $ 6,046 $ 6,109 Traumatic injury claims and assessments 2,410 2,188 4,554 5,199 Total workers’ compensation expense $ 5,433 $ 5,242 $ 10,600 $ 11,308 (1) In accordance with the adoption of ASU 2017-07, “Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” these costs are recorded within Nonoperating expenses in the Condensed Consolidated Income Statements on the line item “Non-service related pension and postretirement benefit costs.”

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	6 Months Ended
	Jun. 30, 2019
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Pension Benefit Costs	The following table details the components of pension benefit costs (credits): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 (In thousands) Interest cost (1) $ 2,259 $ 2,270 $ 4,517 $ 4,541 Expected return on plan assets (1) (2,724 ) (3,080 ) (5,447 ) (6,161 ) Pension settlement (1) (429 ) (1,371 ) (429 ) (1,371 ) Net benefit credit $ (894 ) $ (2,181 ) $ (1,359 ) $ (2,991 ) The following table details the components of other postretirement benefit costs: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 (In thousands) Service cost $ 120 $ 139 $ 240 $ 279 Interest cost (1) 877 919 1,753 1,837 Net benefit cost $ 997 $ 1,058 $ 1,993 $ 2,116

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Schedule of Operating Segment Results	PRB MET Other Thermal Corporate, Other and Eliminations Consolidated (in thousands) Three Months Ended June 30, 2019 Revenues $ 210,149 $ 261,245 $ 98,205 $ 623 $ 570,222 Adjusted EBITDA 14,696 101,936 10,922 (21,990 ) 105,564 Depreciation, depletion and amortization 4,880 17,343 3,689 612 26,524 Accretion on asset retirement obligation 3,135 531 603 868 5,137 Total assets 236,527 605,657 136,899 910,447 1,889,530 Capital expenditures 13,209 31,150 3,211 1,138 48,708 Three Months Ended June 30, 2018 Revenues $ 229,878 $ 259,032 $ 99,814 $ 3,625 $ 592,349 Adjusted EBITDA 26,491 86,657 11,842 (39,605 ) 85,385 Depreciation, depletion and amortization 8,304 18,018 3,701 526 30,549 Accretion on asset retirement obligation 4,885 469 565 1,074 6,993 Total assets 379,613 551,012 134,319 884,469 1,949,413 Capital expenditures 3,065 11,899 2,559 3,073 20,596 Six Months Ended June 30, 2019 Revenues $ 422,878 $ 514,507 $ 184,183 $ 3,837 $ 1,125,405 Adjusted EBITDA 35,279 193,470 17,041 (32,972 ) 212,818 Depreciation, depletion and amortization 9,745 33,725 7,124 1,203 51,797 Accretion on asset retirement obligation 6,271 1,061 1,207 1,735 10,274 Total assets 236,527 605,657 136,899 910,447 1,889,530 Capital expenditures 13,623 62,374 9,461 2,396 87,854 Six Months Ended June 30, 2018 Revenues $ 475,306 $ 497,379 $ 191,334 $ 3,625 $ 1,167,644 Adjusted EBITDA 53,993 170,399 27,510 (61,604 ) 190,298 Depreciation, depletion and amortization 16,727 35,003 7,536 986 60,252 Accretion on asset retirement obligation 9,771 937 1,130 2,147 13,985 Total assets 379,613 551,012 134,319 884,469 1,949,413 Capital expenditures 3,763 17,728 3,765 4,793 30,049
Reconciliation Statement of Segment Income from Operations to Consolidated Income Before Income Taxes	A reconciliation of net income to adjusted EBITDA follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 (In thousands) Net income $ 62,840 $ 43,306 $ 135,581 $ 103,291 Provision for (benefit from) income taxes 91 (3,366 ) 161 (3,910 ) Interest expense, net 2,287 3,498 4,576 7,620 Depreciation, depletion and amortization 26,524 30,549 51,797 60,252 Accretion on asset retirement obligations 5,137 6,993 10,274 13,985 Amortization of sales contracts, net 11 3,248 76 6,299 Loss on sale of Lone Mountain Processing, LLC 4,304 — 4,304 — Net loss resulting from early retirement of debt and debt restructuring — 485 — 485 Non-service related pension and postretirement benefit costs 1,336 (68 ) 3,102 1,235 Reorganization items, net 16 740 (71 ) 1,041 Costs associated with proposed joint venture with Peabody Energy 3,018 — 3,018 — Adjusted EBITDA $ 105,564 $ 85,385 $ 212,818 $ 190,298

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Schedule of effects of revenue recognition	PRB MET Other Thermal Corporate, Other and Eliminations Consolidated (in thousands) Three Months Ended June 30, 2019 North America revenues $ 210,149 $ 54,896 $ 47,885 $ 623 $ 313,553 Seaborne revenues — 206,349 50,320 — 256,669 Total revenues $ 210,149 $ 261,245 $ 98,205 $ 623 $ 570,222 Three Months Ended June 30, 2018 North America revenues $ 229,035 $ 38,323 $ 40,547 $ 3,625 $ 311,530 Seaborne revenues 843 220,709 59,267 — 280,819 Total revenues $ 229,878 $ 259,032 $ 99,814 $ 3,625 $ 592,349 Six Months Ended June 30, 2019 North America revenues $ 422,878 $ 99,562 $ 94,414 $ 3,837 $ 620,691 Seaborne revenues — 414,945 89,769 — 504,714 Total revenues $ 422,878 $ 514,507 $ 184,183 $ 3,837 $ 1,125,405 Six Months Ended June 30, 2018 North America revenues $ 473,395 $ 68,001 $ 84,214 $ 3,625 $ 629,235 Seaborne revenues 1,911 429,378 107,120 — 538,409 Total revenues $ 475,306 $ 497,379 $ 191,334 $ 3,625 $ 1,167,644

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Information related to leases	Information related to leases was as follows: Three Months Ended June 30, 2019 (In thousands) Operating lease information: Operating lease cost $ 916 Operating cash flows from operating leases 869 Weighted average remaining lease term in years 5.45 Weighted average discount rate 5.5 %
Schedule of future minimum lease payments	Future minimum lease payments under non-cancellable leases as of June 30, 2019 were as follows: Year Amount (In thousands) 2019 $ 2,101 2020 3,616 2021 3,367 2022 3,292 2023 3,261 Thereafter 11,153 Total minimum lease payments $ 26,790 Less imputed interest (5,012 ) Total operating lease liability $ 21,778 As reflected on balance sheet: Accrued expenses and other current liabilities $ 2,909 Other noncurrent liabilities 18,869 Total operating lease liability $ 21,778

Joint Venture with Peabody En_2

Joint Venture with Peabody Energy (Details)	Jun. 18, 2019USD ($)
Peabody Energy Corporation | Senior Notes | Senior Notes Due 2022
Schedule of Equity Method Investments [Line Items]
Debt instrument stated interest rate	6.00%
Peabody Energy Corporation | Senior Notes | Senior Notes Due 2025
Schedule of Equity Method Investments [Line Items]
Debt instrument stated interest rate	6.375%
Implementation Agreement
Schedule of Equity Method Investments [Line Items]
Economic interest held	33.50%
Termination fee payable to non-terminating party	$ 40,000,000
Reduction in contract termination fee payable to non-terminating party	$ 25,000,000
Implementation Agreement | Peabody Energy Corporation
Schedule of Equity Method Investments [Line Items]
Economic interest held	66.50%

Loss on Sale of Lone Mountain_2

Loss on Sale of Lone Mountain Processing, LLC (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on sale of Lone Mountain Processing, LLC	$ (4,304)	$ 0	$ (4,304)	$ 0
Lone Mountain Processing Inc and 2 idled mining companies | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on sale of Lone Mountain Processing, LLC			$ (4,300)		$ 21,300

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Accumulated Other Comprenhensive Income (Loss) [Roll Forward]
Beginning Balance	$ 704,821
Unrealized gains	7,069
Amounts reclassified from AOCI	(3,577)
Ending Balance	697,950
Accumulated Other Comprehensive Income
Accumulated Other Comprenhensive Income (Loss) [Roll Forward]
Beginning Balance	43,296
Ending Balance	46,788
Derivative instruments
Accumulated Other Comprenhensive Income (Loss) [Roll Forward]
Beginning Balance	3,328
Unrealized gains	3,072
Amounts reclassified from AOCI	(3,133)
Ending Balance	3,267
Pension, postretirement and other post-employment benefits
Accumulated Other Comprenhensive Income (Loss) [Roll Forward]
Beginning Balance	40,311
Unrealized gains	3,331
Amounts reclassified from AOCI	(429)
Ending Balance	43,213
Available-for-sale securities
Accumulated Other Comprenhensive Income (Loss) [Roll Forward]
Beginning Balance	(343)
Unrealized gains	666
Amounts reclassified from AOCI	(15)
Ending Balance	$ 308

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Schedule of Reclassifications) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Revenues	$ 570,222	$ 592,349	$ 1,125,405	$ 1,167,644
Interest expense	(4,375)	(5,050)	(8,807)	(10,445)
Provision for (benefit from) income taxes	(91)	3,366	(161)	3,910
Interest and investment income	2,088	1,552	4,231	2,825
Net income	62,840	43,306	135,581	103,291
Reclassification out of Accumulated Other Comprehensive Income | Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Revenues	1,743	0	2,104	0
Interest expense	514	348	1,029	488
Provision for (benefit from) income taxes	0	0	0	0
Net income	2,257	348	3,133	488
Reclassification out of Accumulated Other Comprehensive Income | Pension, postretirement and other post-employment benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Provision for (benefit from) income taxes	0	0	0	0
Non-service related pension and postretirement benefit (costs) credits	429	1,371	429	1,371
Net income	429	1,371	429	1,371
Reclassification out of Accumulated Other Comprehensive Income | Available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Provision for (benefit from) income taxes	0	0	0	0
Interest and investment income	15	16	15	16
Net income	$ 15	$ 16	$ 15	$ 16

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Coal	$ 83,432	$ 40,982
Repair parts and supplies	89,409	84,488
Inventories	172,841	125,470
Allowance for slow-moving and obsolete inventories	$ 1,400	$ 600

Investments in Available-for-_3

Investments in Available-for-Sale Securities (Schedule of Investments) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Cost Basis	$ 162,349	$ 163,140
Available-for-sale, Gains	341	15
Available-for-sale, Losses	(34)	(358)
Available-for-sale, Fair Value	162,656	162,797
Available-for-sale, Short-Term Investments	162,656	162,797
Short-term Investments
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Short-Term Investments	162,656	162,797
Other Assets
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Other Assets	0	0
U.S. government and agency securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Cost Basis	58,283	100,003
Available-for-sale, Gains	94	11
Available-for-sale, Losses	0	(126)
Available-for-sale, Fair Value	58,377	99,888
U.S. government and agency securities | Short-term Investments
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Short-Term Investments	58,377	99,888
U.S. government and agency securities | Other Assets
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Other Assets	0	0
Corporate notes and bonds
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Cost Basis	104,066	63,137
Available-for-sale, Gains	247	4
Available-for-sale, Losses	(34)	(232)
Available-for-sale, Fair Value	104,279	62,909
Corporate notes and bonds | Short-term Investments
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Short-Term Investments	104,279	62,909
Corporate notes and bonds | Other Assets
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Other Assets	$ 0	$ 0

Investments in Available-for-_4

Investments in Available-for-Sale Securities (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Abstract]
Unrealized losses owned for less than 12 months	$ 25.2	$ 115.2
Unrealized losses owed for over a year	$ 0	$ 32.4

Derivatives (Narrative) (Detail

Derivatives (Narrative) (Details) gal in Millions, $ in Millions	6 Months Ended		12 Months Ended
	Dec. 31, 2019USD ($)	Jun. 30, 2019USD ($)$ / optiongal	Dec. 31, 2020USD ($)	Jun. 30, 2020$ / option	Dec. 31, 2018USD ($)
Derivative [Line Items]
Current asset representing cash collateral posted | $		$ 2.1			$ 24.7
Derivative contracts expected to be reclassified from OCI into earnings | $		$ 5.9
Not Designated as Hedging Instrument | Heating Oil
Derivative [Line Items]
Quantities under derivative contracts (in gallons)		10
Derivative, average price risk option strike price (in usd per gallon) | $ / option		2.34
Percent of expected requirements covered		22.00%
Not Designated as Hedging Instrument | Diesel Purchases | Minimum
Derivative [Line Items]
Diesel fuel purchased annually (in gallons)		40
Not Designated as Hedging Instrument | Diesel Purchases | Maximum
Derivative [Line Items]
Diesel fuel purchased annually (in gallons)		47
Scenario, Forecast
Derivative [Line Items]
Value of trading portfolio realized - gains (losses) | $	$ (0.6)		$ (0.5)
Scenario, Forecast | Not Designated as Hedging Instrument | Heating Oil
Derivative [Line Items]
Derivative, average price risk option strike price (in usd per gallon) | $ / option				2.30
NYMEX | Not Designated as Hedging Instrument | Diesel Purchases
Derivative [Line Items]
Quantities under derivative contracts (in gallons)		12
Derivative, average price risk option strike price (in usd per gallon) | $ / option		1.91
NYMEX | Not Designated as Hedging Instrument | Diesel Purchases | Heating Oil
Derivative [Line Items]
Quantities under derivative contracts (in gallons)		32

Derivatives (Schedule of Price

Derivatives (Schedule of Price Risk Derivatives) (Details) T in Thousands	6 Months Ended
	Jun. 30, 2019T
Coal sales
Derivative [Line Items]
Derivatives held (in tons)	2,029
Coal purchases
Derivative [Line Items]
Derivatives held (in tons)	997
2019 | Coal sales
Derivative [Line Items]
Derivatives held (in tons)	1,540
2019 | Coal purchases
Derivative [Line Items]
Derivatives held (in tons)	772
2020 | Coal sales
Derivative [Line Items]
Derivatives held (in tons)	489
2020 | Coal purchases
Derivative [Line Items]
Derivatives held (in tons)	225

Derivatives (Disclosure Of Fair

Derivatives (Disclosure Of Fair Value Of Derivatives) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Derivative Assets	$ 88,140	$ 18,879
Derivative Liabilities	(73,244)	(31,089)
Effect of counterparty netting in derivative assets	(72,594)	(17,801)
Effect of counterparty netting in derivative liabilities	72,594	17,801
Derivative Asset	15,546	1,078
Derivative Liability	(650)	(13,288)
Net derivatives as classified in the balance sheets	14,896	(12,210)
Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets	80,412	16,537
Derivative Liabilities	(72,607)	(30,284)
Not Designated as Hedging Instrument | Coal Contract
Derivative [Line Items]
Derivative Assets	45,685	10,329
Derivative Liabilities	(46,807)	(10,701)
Coal Contract | Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets	7,728	2,342
Derivative Liabilities	(637)	(805)
Coal Contract | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets	33,804	5,672
Derivative Liabilities	(25,150)	(19,579)
Heating oil — diesel purchases | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets	923	532
Derivative Liabilities	(650)	0
Natural gas | Not Designated as Hedging Instrument
Derivative [Line Items]
Derivative Assets	0	4
Derivative Liabilities	$ 0	$ (4)

Derivatives (Net Derivatives As

Derivatives (Net Derivatives As Reflected On The Balance Sheets) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Net derivatives as classified in the balance sheet	$ 14,896	$ (12,210)
Accrued expenses and other current liabilities
Derivatives, Fair Value [Line Items]
Net derivatives as classified in the balance sheet	(650)	(13,288)
Heating oil and coal | Other current assets
Derivatives, Fair Value [Line Items]
Net derivatives as classified in the balance sheet	$ 15,546	$ 1,078

Derivatives (Effects Of Derivat

Derivatives (Effects Of Derivatives On Measures Of Financial Performance) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of coal derivatives and coal trading activities, net	$ 8,400	$ (15,138)	$ 21,381	$ (11,724)
Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income	3,670	(12,757)	8,341	(8,068)
Gains (Losses) Reclassified from Other Comprehensive Income into Income	1,743		2,101
Designated as Hedging Instrument | Coal sales | Coal Contract | Coal sales
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income	4,010	(15,462)	9,247	(10,231)
Gains (Losses) Reclassified from Other Comprehensive Income into Income	1,743	0	2,787	0
Designated as Hedging Instrument | Coal purchases | Coal Contract | Coal purchases
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Other Comprehensive Income	(340)	2,705	(906)	2,163
Gains (Losses) Reclassified from Other Comprehensive Income into Income	0		(686)
Not Designated as Hedging Instrument | Coal Contract | Coal and natural gas realized and unrealized
Derivative Instruments, Gain (Loss) [Line Items]
Realized and Unrealized Gain (Loss) on Derivatives	(718)	384	(1,101)	942
Unrealized Gain (Loss) on Derivatives	9,137	(15,505)	22,562	(12,630)
Not Designated as Hedging Instrument | Coal Contract | Other operating (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain (Loss) on Derivatives	(881)	(1,649)	(5,292)	(2,680)
Not Designated as Hedging Instrument | Natural gas | Coal and natural gas realized and unrealized
Derivative Instruments, Gain (Loss) [Line Items]
Realized and Unrealized Gain (Loss) on Derivatives	(19)	(17)	(80)	(36)
Not Designated as Hedging Instrument | Heating oil — diesel purchases | Other operating (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Heating oil realized and unrealized gains and losses	$ (1,369)	$ 3,657	$ (732)	$ 3,675

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Payroll and employee benefits	$ 49,418	$ 57,166
Taxes other than income taxes	72,502	75,017
Interest	221	156
Acquired sales contracts	319	570
Workers’ compensation	18,108	20,044
Asset retirement obligations	12,297	13,113
Other	9,876	17,448
Accrued expenses and other current liabilities	$ 162,741	$ 183,514

Debt and Financing Arrangemen_3

Debt and Financing Arrangements (Long term Debt) (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018	Mar. 07, 2017
Debt Instrument [Line Items]
Term loan	$ 292,224,000	$ 293,626,000
Other	21,669,000	30,449,000
Debt issuance costs	(5,562,000)	(6,092,000)
Total	308,331,000	317,983,000
Less: current maturities of debt	13,068,000	17,797,000
Long-term debt	295,263,000	$ 300,186,000
Senior Notes | New Term Loan Debt Facility
Debt Instrument [Line Items]
Debt instrument, face amount	$ 293,300,000		$ 300,000,000

Debt and Financing Arrangemen_4

Debt and Financing Arrangements (Narrative) (Details) - USD ($)	Aug. 27, 2018	Apr. 27, 2018	Apr. 03, 2018	Apr. 27, 2017	Mar. 07, 2017	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Line of Credit Facility [Line Items]
Fair value of derivative assets						$ 88,140,000	$ 88,140,000	$ 18,879,000
Interest Rate Swap
Line of Credit Facility [Line Items]
Interest rate swaps settlements gains						500,000	1,000,000
Other Noncurrent Assets | Interest Rate Swap
Line of Credit Facility [Line Items]
Fair value of derivative assets						(2,600,000)	(2,600,000)
Senior Notes | New Term Loan Debt Facility
Line of Credit Facility [Line Items]
Net cash proceeds of from debt issuances and other non-ordinary sales or dispositions (percent)					100.00%
Default to indebtedness					$ 50,000,000
Default to surety, reclamation or similar bond					50,000,000
Default to uninsured judgment					50,000,000
Uninsured losses or proceedings against					50,000,000
Senior Notes | New Term Loan Debt Facility | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate			2.75%
Basis spread on variable rate, floor			1.00%
Senior Notes | New Term Loan Debt Facility | Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate			1.75%
New Term Loan Debt Facility | Senior Notes
Line of Credit Facility [Line Items]
Debt instrument, face amount					$ 300,000,000	$ 293,300,000	293,300,000
Percentage of face amount					99.50%
Quarterly amortization payments					$ 750,000
Amount of voting equity interests of domestic subsidiaries guaranteed (percent)					100.00%
Amount of voting equity interests of foreign owned subsidiaries guaranteed (percent)					65.00%
New Term Loan Debt Facility | Senior Notes | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate						2.75%
Line of Credit | Secured Debt | Regions Bank
Line of Credit Facility [Line Items]
Maximum borrowing capacity								50,000,000
Facility size, increase								$ 10,000,000
Line of Credit | Secured Debt | Accounts Receivable Securitization Facility | Arch Receivable Company, LLC
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 160,000,000
Maturity date	3 years	3 years
Current borrowing capacity						$ 86,500,000	86,500,000
Covenant minimum amount				$ 175,000,000
Liquidity threshold, consecutive days		60 days
Liquidity threshold		364 days
Liquidity threshold, expiration period		60 days
Letters of credit outstanding						15,700,000	15,700,000
Line of Credit | Secured Debt | Inventory-Based Revolving Credit Facility | Regions Bank
Line of Credit Facility [Line Items]
Debt instrument, face amount				40,000,000
Covenant minimum amount				$ 175,000,000
Liquidity threshold, consecutive days		60 days
Liquidity threshold		364 days
Liquidity threshold, expiration period		60 days
Letters of credit outstanding						35,600,000	35,600,000
Percentage of coal inventory borrowing base				85.00%
Percentage of parts and supplies inventory borrowing base				85.00%
Percentage of clause borrowing base				35.00%
Percent of eligible cash				100.00%
Covenant amount (less than)				$ 250,000,000
Additional availability for borrowings						$ 14,400,000	$ 14,400,000
Line of Credit | Secured Debt | Inventory-Based Revolving Credit Facility | LIBOR | Regions Bank | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate				2.00%
Line of Credit | Secured Debt | Inventory-Based Revolving Credit Facility | LIBOR | Regions Bank | Maximum
Line of Credit Facility [Line Items]
Percentage of clause borrowing base				2.50%
Line of Credit | Secured Debt | Inventory-Based Revolving Credit Facility | Base Rate | Regions Bank | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate				1.00%
Line of Credit | Secured Debt | Inventory-Based Revolving Credit Facility | Base Rate | Regions Bank | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate				1.50%

Debt and Financing Arrangemen_5

Debt and Financing Arrangements (Interest rate derivatives) (Details) $ in Millions	Jun. 30, 2019USD ($)
Interest rate swap, effective 2019
Debt Instrument [Line Items]
Notional Amount	$ 250
Fixed Rate	2.025%
Interest rate swap, effective 2020
Debt Instrument [Line Items]
Notional Amount	$ 200
Fixed Rate	2.249%
Interest rate swap, effective 2021
Debt Instrument [Line Items]
Notional Amount	$ 100
Fixed Rate	2.315%

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income tax provision at statutory rate	$ 13,216	$ 8,387	$ 28,506	$ 20,870
Percentage depletion allowance	(3,457)	(2,488)	(7,764)	(7,095)
State taxes, net of effect of federal taxes	831	583	1,843	1,337
Change in valuation allowance	(11,292)	(7,317)	(23,805)	(17,956)
Current expense associated with uncertain tax positions	844	792	1,437	2,181
Other, net	(51)	(3,323)	(56)	(3,247)
Provision for (benefit from) income taxes	$ 91	$ (3,366)	$ 161	$ (3,910)

Fair Value Measurements (Summar

Fair Value Measurements (Summary Of Financial Assets And Liabilities Accounted For At Fair Value) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Assets:
Investments in marketable securities	$ 162,656	$ 162,797
Liabilities:
Derivatives	650	$ 13,288
Interest Rate Swap
Assets:
Investments in marketable securities	162,656
Derivatives	15,378
Total assets	178,034
Liabilities:
Derivatives	3,048
Interest Rate Swap | Level 1
Assets:
Investments in marketable securities	58,377
Derivatives	13,883
Total assets	72,260
Liabilities:
Derivatives	0
Interest Rate Swap | Level 2
Assets:
Investments in marketable securities	104,279
Derivatives	740
Total assets	105,019
Liabilities:
Derivatives	3,048
Interest Rate Swap | Level 3
Assets:
Investments in marketable securities	0
Derivatives	755
Total assets	755
Liabilities:
Derivatives	$ 0

Fair Value Measurements (Summ_2

Fair Value Measurements (Summary Of Change In The Fair Values Of Financial Instruments Categorized As Level 3) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 851	$ 532
Realized and unrealized gains recognized in earnings, net	(398)	(542)
Purchases	537	1,000
Issuances	0	0
Settlements	(235)	(235)
Ending balance	$ 755	$ 755

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of senior notes and other long-term debt, including amounts classified as current	$ 314.6	$ 314.6	$ 318.6
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net unrealized gains (losses) related to level 3 financial instruments	$ (1.4)	$ (1.1)

Earnings per Common Share (Deta

Earnings per Common Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Weighted average shares outstanding:
Basic weighted average shares outstanding (in shares)	16,543	20,156	17,018	20,529
Effect of dilutive securities (in shares)	1,238	880	1,172	927
Diluted weighted average shares outstanding (in shares)	17,781	21,036	18,190	21,456

Workers Compensation Expense (D

Workers Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Occupational disease
Accrued Workers Compensation [Line Items]
Service cost	$ 1,669	$ 1,860	$ 3,338	$ 3,720
Interest cost	1,354	1,194	2,708	2,389
Net benefit credit	3,023	3,054	6,046	6,109
Traumatic injury claims and assessments
Accrued Workers Compensation [Line Items]
Traumatic injury claims and assessments	2,410	2,188	4,554	5,199
Total workers’ compensation expense
Accrued Workers Compensation [Line Items]
Total workers’ compensation expense	$ 5,433	$ 5,242	$ 10,600	$ 11,308

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined benefit pension plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 2,259	$ 2,270	$ 4,517	$ 4,541
Expected return on plan assets	(2,724)	(3,080)	(5,447)	(6,161)
Pension settlement	(429)	(1,371)	(429)	(1,371)
Net benefit credit	(894)	(2,181)	(1,359)	(2,991)
Other postretirement benefits plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	120	139	240	279
Interest cost	877	919	1,753	1,837
Net benefit credit	$ 997	$ 1,058	$ 1,993	$ 2,116

Segment Information (Schedule O

Segment Information (Schedule Of Operating Segment Results) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)Segment	Jun. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Segment Reporting [Abstract]
Number of reportable segments | Segment			2
Segment Reporting Information [Line Items]
Revenues	$ 570,222	$ 592,349	$ 1,125,405	$ 1,167,644
Adjusted EBITDA	105,564	85,385	212,818	190,298
Depreciation, depletion and amortization	26,524	30,549	51,797	60,252
Accretion on asset retirement obligations	5,137	6,993	10,274	13,985
Total assets	1,889,530	1,949,413	1,889,530	1,949,413	$ 1,887,060
Capital expenditures	48,708	20,596	87,854	30,049
Operating Segments | PRB
Segment Reporting Information [Line Items]
Revenues	210,149	229,878	422,878	475,306
Adjusted EBITDA	14,696	26,491	35,279	53,993
Depreciation, depletion and amortization	4,880	8,304	9,745	16,727
Accretion on asset retirement obligations	3,135	4,885	6,271	9,771
Total assets	236,527	379,613	236,527	379,613
Capital expenditures	13,209	3,065	13,623	3,763
Operating Segments | MET
Segment Reporting Information [Line Items]
Revenues	261,245	259,032	514,507	497,379
Adjusted EBITDA	101,936	86,657	193,470	170,399
Depreciation, depletion and amortization	17,343	18,018	33,725	35,003
Accretion on asset retirement obligations	531	469	1,061	937
Total assets	605,657	551,012	605,657	551,012
Capital expenditures	31,150	11,899	62,374	17,728
Operating Segments | Other Thermal
Segment Reporting Information [Line Items]
Revenues	98,205	99,814	184,183	191,334
Adjusted EBITDA	10,922	11,842	17,041	27,510
Depreciation, depletion and amortization	3,689	3,701	7,124	7,536
Accretion on asset retirement obligations	603	565	1,207	1,130
Total assets	136,899	134,319	136,899	134,319
Capital expenditures	3,211	2,559	9,461	3,765
Corporate, Other and Eliminations
Segment Reporting Information [Line Items]
Revenues	623	3,625	3,837	3,625
Adjusted EBITDA	(21,990)	(39,605)	(32,972)	(61,604)
Depreciation, depletion and amortization	612	526	1,203	986
Accretion on asset retirement obligations	868	1,074	1,735	2,147
Total assets	910,447	884,469	910,447	884,469
Capital expenditures	$ 1,138	$ 3,073	$ 2,396	$ 4,793

Segment Information (Reconcilia

Segment Information (Reconciliation Segment Income To Consolidated Income Before Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting [Abstract]
Net income	$ 62,840	$ 43,306	$ 135,581	$ 103,291
Provision for (benefit from) income taxes	91	(3,366)	161	(3,910)
Interest expense, net	2,287	3,498	4,576	7,620
Depreciation, depletion and amortization	26,524	30,549	51,797	60,252
Accretion on asset retirement obligations	5,137	6,993	10,274	13,985
Amortization of sales contracts, net	11	3,248	76	6,299
Loss on sale of Lone Mountain Processing, Inc.	4,304	0	4,304	0
Net loss resulting from early retirement of debt and debt restructuring	0	485	0	485
Non-service related pension and postretirement benefit costs	1,336	(68)	3,102	1,235
Reorganization items, net	16	740	(71)	1,041
Costs associated with proposed joint venture with Peabody Energy, Inc.	3,018	0	3,018	0
Adjusted EBITDA	$ 105,564	$ 85,385	$ 212,818	$ 190,298

Revenue Recognition (Disaggrega

Revenue Recognition (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 570,222	$ 592,349	$ 1,125,405	$ 1,167,644
Corporate, Other and Eliminations
Disaggregation of Revenue [Line Items]
Revenues	623	3,625	3,837	3,625
North America revenues
Disaggregation of Revenue [Line Items]
Revenues	313,553	311,530	620,691	629,235
North America revenues | Corporate, Other and Eliminations
Disaggregation of Revenue [Line Items]
Revenues	623	3,625	3,837	3,625
Seaborne revenues
Disaggregation of Revenue [Line Items]
Revenues	256,669	280,819	504,714	538,409
Seaborne revenues | Corporate, Other and Eliminations
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
PRB | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	210,149	229,878	422,878	475,306
PRB | North America revenues | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	210,149	229,035	422,878	473,395
PRB | Seaborne revenues | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	0	843	0	1,911
MET | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	261,245	259,032	514,507	497,379
MET | North America revenues | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	54,896	38,323	99,562	68,001
MET | Seaborne revenues | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	206,349	220,709	414,945	429,378
Other Thermal | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	98,205	99,814	184,183	191,334
Other Thermal | North America revenues | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	47,885	40,547	94,414	84,214
Other Thermal | Seaborne revenues | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	$ 50,320	$ 59,267	$ 89,769	$ 107,120

Revenue Recognition (Narrative)

Revenue Recognition (Narrative) (Details) T in Millions	Jun. 30, 2019T
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations, fixed price contracts (in tons)	38.9
Remaining performance obligations, variable price contracts (in tons)	4.9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations, fixed price contracts (in tons)	64.3
Remaining performance obligations, variable price contracts (in tons)	5.7

Leases (Narrative) (Details)

Leases (Narrative) (Details) $ in Millions	Jun. 30, 2019USD ($)
Lessee, Lease, Description [Line Items]
Right-of-use operating lease asset	$ 21.1
Minimum
Lessee, Lease, Description [Line Items]
Operating lease, remaining lease terms	1 year
Maximum
Lessee, Lease, Description [Line Items]
Operating lease, remaining lease terms	8 years

Leases (Information Related to

Leases (Information Related to Leases) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Operating lease information:
Operating lease cost	$ 916
Operating cash flows from operating leases	$ 869
Weighted average remaining lease term in years	5 years 5 months 12 days
Weighted average discount rate	5.50%

Leases (Future Minimum Lease Pa

Leases (Future Minimum Lease Payments) (Details) $ in Thousands	Jun. 30, 2019USD ($)
Leases [Abstract]
2019	$ 2,101
2020	3,616
2021	3,367
2022	3,292
2023	3,261
Thereafter	11,153
Total minimum lease payments	26,790
Less imputed interest	(5,012)
Total operating lease liability	21,778
As reflected on balance sheet:
Accrued expenses and other current liabilities	2,909
Other noncurrent liabilities	18,869
Total operating lease liability	$ 21,778

Uncategorized Items - aci-20190

Label	Element	Value
Restricted Cash and Cash Equivalents, Current	us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue	$ 0
Restricted Cash and Cash Equivalents, Current	us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue	$ 0