Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities:
Net income (loss)	$ 19,756	$ (31,213)
Non-cash elements included in net income (loss):
Depreciation, depletion and amortization	98,121	84,185
Write-down to stockpile inventory	6,431	0
Gain on sale of investments	(1,158)	0
Unrealized loss (gain) on investments	4,256	(5,431)
Provision for reclamation and closure costs	6,183	3,093
Stock compensation	3,302	2,428
Deferred income taxes	(8,562)	(5,165)
Amortization of loan origination fees and loss on extinguishment of debt	918	2,624
Loss on derivative contracts	2,116	11,188
Foreign exchange loss (gain)	4,455	(3,725)
Foundation grant	0	1,970
Other non-cash items, net	153	573
Change in assets and liabilities:
Accounts receivable	(9,432)	(6,050)
Inventories	5,719	(4,580)
Other current and non-current assets	4,125	(924)
Accounts payable and accrued liabilities	(6,489)	(15,415)
Accrued payroll and related benefits	(5,351)	5,418
Accrued taxes	(999)	3,912
Accrued reclamation and closure costs and other non-current liabilities	696	(435)
Cash provided by operating activities	124,240	42,453
Investing activities:
Additions to properties, plants, equipment and mineral interests	(53,311)	(30,689)
Proceeds from disposition of properties, plants and equipment	131	200
Purchases of investments	0	(637)
Net cash used in investing activities	53,180	31,126
Financing activities:
Acquisition of treasury shares	(4,525)	(2,745)
Dividends paid to common stockholders	(10,715)	(2,622)
Dividends paid to preferred stockholders	(276)	(276)
Credit facility fees paid	(82)	(551)
Borrowings on debt	0	679,500
Repayments of debt	0	(666,500)
Repayments of finance leases	(3,770)	(2,840)
Net cash (used in) provided by financing activities	(19,368)	3,966
Effect of exchange rates on cash	(28)	(1,794)
Net increase in cash, cash equivalents and restricted cash and cash equivalents	51,664	13,499
Cash, cash equivalents and restricted cash and cash equivalents at beginning of period	130,883	63,477
Cash, cash equivalents and restricted cash and cash equivalents at end of period	182,547	76,976
Supplemental disclosure of cash flow information:
Cash paid for interest	18,499	15,837
Cash paid for income and mining taxes	9,469	5,345
Significant non-cash investing and financing activities:
Addition of finance lease obligations and right-of-use assets	3,120	3,100
Payment of accrued compensation in stock	0	5,095
Accounts receivable for proceeds on exchange of investments	$ 1,832	$ 0