Note 14 - Properties, Plants, Equipment and Mineral Interests, and Lease Commitments (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

Property, Plant and Equipment [Table Text Block]

	December 31,
	2021		2020
			Revised
Mining properties, including asset retirement obligations	$	818,582	$	818,819
Development costs		549,666		526,714
Plants and equipment		1,446,183		1,410,209
Land		34,931		32,983
Mineral interests		972,754		969,589
Construction in progress		86,903		66,090
		3,909,019		3,824,404
Less accumulated depreciation, depletion and amortization		1,598,209		1,446,330
Net carrying value	$	2,310,810	$	2,378,074