CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income	$ (3,121)	$ 882
Adjustments to reconcile net income to net cash from operating activities:
Deferred income taxes	(4,650)	895
Depreciation and amortization	7,535	3,763
Stock-based compensation	470	336
Other operating adjustments	1,780	(128)
Changes in operating assets and liabilities:
Accounts receivable	4,320	(2,771)
Inventories	(3,495)	(6,324)
Prepaid expenses and other current assets	175	221
Other non-current assets	921	40
Accounts payable and other accrued liabilities	(802)	3,222
Mining royalty and income taxes payable, net	1,844	(784)
Net cash provided by operating activities	4,977	(648)
Cash flows from investing activities:
Capital expenditures	(6,929)	(8,786)
Other investing activities	1	1
Net cash used in investing activities	(6,928)	(8,785)
Cash flows from financing activities:
Proceeds from the exercise of stock options		98
Proceeds from issuance of stock	10,350	10,806
Dividends paid	(657)	(303)
Repayment of loans payable	(216)	(187)
Repayment of finance leases	(109)	(101)
Net cash provided by (used in) financing activities	9,368	10,313
Effect of exchange rate changes on cash and cash equivalents	(127)	(115)
Net increase (decrease) in cash and cash equivalents	7,290	765
Cash and cash equivalents at beginning of period	11,076	7,762
Cash and cash equivalents at end of period	18,366	8,527
Supplemental Cash Flow Information
Interest expense paid	32	42
Income and mining taxes paid	197	209
Non-cash investing activities:
Change in capital expenditures in accounts payable	(950)	2,303
Change in estimate for asset retirement costs	$ 435	462
Equipment purchased through loan payable		$ 330