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