Note 10 - Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2020

Notes Tables

Property, Plant and Equipment [Table Text Block]

	December 31,
	2020		2019
Plant and Equipment	$	3,134,149	$	3,028,514
Coal Properties and Surface Lands		874,567		872,909
Airshafts		452,976		437,003
Mine Development		354,691		342,706
Advance Mining Royalties		327,313		327,048
Total Property, Plant and Equipment		5,143,696		5,008,180
Less: Accumulated Depreciation, Depletion and Amortization		3,094,634		2,916,015
Total Property, Plant and Equipment - Net	$	2,049,062	$	2,092,165