Acquisition-Related Obligations (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Schedule of Acquisition-Related Obligations

Acquisition-related obligations consisted of the following:

	December 31,
	2019			2018
Contingent Revenue Obligation	$	52,427		$	59,880
Environmental Settlement Obligations	16,305			19,306
Reclamation Funding Liability	12,000			22,000
Retiree Committee VEBA Funding Settlement Liability	—			3,500
UMWA Funds Settlement Liability	4,000			6,000
Discount	(4,834		)	(10,356		)
Total acquisition-related obligations	79,898			100,330
Less current portion	(33,639		)	(27,334		)
Acquisition-related obligations, net of current portion	$	46,259		$	72,996