Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 181,494	$ 129,830
Accounts receivable:
Trade	41,311	27,864
Other, net	9,334	11,329
Inventories:
Concentrates, doré, and stockpiled ore	43,814	57,936
Materials and supplies	39,148	38,608
Derivatives assets	5,879	3,470
Other current assets	10,198	15,644
Total current assets	331,178	284,681
Investments	11,083	15,148
Restricted cash	1,053	1,053
Properties, plants, equipment and mineral interests, net	2,305,359	2,345,219
Operating lease right-of-use assets	8,902	10,628
Deferred income taxes	5,090	2,912
Derivatives assets	4,852	4,558
Other non-current assets	3,721	3,525
Total assets	2,671,238	2,667,724
Current liabilities:
Accounts payable and accrued liabilities	62,183	68,516
Accrued payroll and related benefits	24,270	31,807
Accrued taxes	4,838	8,349
Finance leases	6,223	6,491
Operating leases	2,540	3,008
Accrued interest	14,480	14,157
Derivatives liabilities	6,757	11,737
Other current liabilities	116	138
Accrued reclamation and closure costs	7,994	5,582
Total current liabilities	129,401	149,785
Finance leases	8,905	9,274
Operating leases	6,368	7,634
Accrued reclamation and closure costs	112,651	110,466
Long-term debt	508,611	507,242
Deferred tax liability	143,181	144,330
Pension liability	30,237	44,144
Derivatives liabilities	7,104	18
Other non-current liabilities	4,098	4,346
Total liabilities	950,556	977,239
Commitments and contingencies (Notes 4, 7, 8, and 10)
Preferred stock, 5,000,000 shares authorized: Series B preferred stock, $0.25 par value, 157,816 shares issued and outstanding, liquidation preference — $7,891	39	39
Common stock, 25 cent par value, 750,000,000 authorized shares; issued June 30, 2021 — 544,217,951 shares and December 31, 2020 — 538,487,415 shares	136,065	134,629
Capital surplus	2,024,645	2,003,576
Accumulated deficit	(382,609)	(391,374)
Accumulated other comprehensive loss	(29,437)	(32,889)
Less treasury stock, at cost; June 30, 2021 — 7,395,295 shares and December 31, 2020 — 6,821,044 shares issued and held in treasury	(28,021)	(23,496)
Total stockholders’ equity	1,720,682	1,690,485
Total liabilities and stockholders’ equity	$ 2,671,238	$ 2,667,724