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Note 9 - Shareholders' Equity (Details Textual) |  |  | 1 Months Ended | 3 Months Ended | 9 Months Ended | 31 Months Ended | 77 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Nov. 06, 2018 USD ($) $ / shares | Jul. 20, 2018 $ / shares shares | Mar. 31, 2018 USD ($) shares | Sep. 30, 2018 $ / shares $ / item shares | Aug. 31, 2018 USD ($) shares | Sep. 30, 2017 $ / shares shares | Sep. 30, 2018 USD ($) $ / shares $ / item shares | Sep. 30, 2017 USD ($) $ / shares shares | Sep. 30, 2018 USD ($) $ / item shares | Sep. 30, 2018 $ / shares $ / item shares | Feb. 23, 2016 USD ($) | May 08, 2012 shares
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period |  |  | 1,237,369 |  |  |  |  |  |  |  |  |
Allocated Share-based Compensation Expense, Total | $ |  |  | $ 4,900,000 |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Measurement Period Used to Value Performance-based Awards |  |  |  |  | 3 years |  |  |  |  |  |  |
Shares Paid for Tax Withholding for Share Based Compensation |  |  |  |  |  |  | 697,341 | 588,240 |  |  |  |
Payments Related to Tax Withholding for Share-based Compensation | $ |  |  |  |  |  |  | $ 2,700,000 | $ 3,000,000 |  |  |  |
Treasury Stock Acquired, Average Cost Per Share | $ / shares |  |  |  |  |  |  | $ 3.86 | $ 5.09 |  |  |  |
Common Stock, Dividends, Per Share, Declared | $ / shares |  |  |  | $ 0.0025 |  | $ 0.0025 | $ 0.0075 | $ 0.0075 |  |  |  |
Average Realized Silver Price | $ / item |  |  |  |  |  |  | 14.68 |  |  |  |  |
Average Realized Silver Price, Minimum Dividend, Threshold | $ / item |  |  |  | 30 |  |  | 30 |  | 30 | 30 |  |
Stock Issued During Period, Shares, New Issues |  |  |  |  |  |  | 1,025,911 |  | 5,634,758 |  |  |
Stock Issued During Period, Value, New Issues | $ |  |  |  |  |  |  | $ 3,100,000 |  | $ 20,800,000 |  |  |
Payments for Brokerage Fees | $ |  |  |  |  |  |  | $ 100,000 |  | $ 500,000 |  |  |
Class of Warrant or Right, Outstanding |  |  |  |  |  | 0 |  | 0 |  |  |  |
Klondex Mines Ltd [Member] |  |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues |  | 75,276,176 |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares |  | $ 8.02 |  |  |  |  |  |  |  |  |  |
Warrants in Connection with Klondex Mines Acquisition [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Issued During Period |  | 4,136,000 |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right |  | 1 |  |  |  |  |  |  |  |  |  |
Warrants in Connection with Klondex Mines Acquisition Expiring April 2032 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Outstanding |  | 2,068,000 |  |  |  |  |  |  |  |  |  |
Warrants in Connection with Klondex Mines Acquisition Expiring February 2029 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Outstanding |  | 2,068,000 |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares |  | $ 1.57 |  |  |  |  |  |  |  |  |  |
Common Stock Repurchase Program [Member] |  |  |  |  |  |  |  |  |  |  |  |
Treasury Stock Acquired, Average Cost Per Share | $ / shares |  |  |  |  |  |  |  |  |  | $ 3.99 |  |
Stock Repurchase Program, Number of Shares Authorized to be Repurchased |  |  |  |  |  |  |  |  |  |  |  | 20,000,000
Cumulative Stock Repurchased |  |  |  | 934,100 |  |  | 934,100 |  | 934,100 | 934,100 |  |
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased |  |  |  | 19,100,000 |  |  | 19,100,000 |  | 19,100,000 | 19,100,000 |  |
Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |
Common Stock, Dividends, Per Share, Declared | $ / shares | $ 0.0025 |  |  |  |  |  |  |  |  |  |  |
Dividends, Common Stock, Total | $ | $ 1.20 |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Member] | Common Stock Repurchase Program [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share Price | $ / shares | $ 2.49 |  |  |  |  |  |  |  |  |  |  |
Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |
Common Stock, Dividends, Per Share, Declared | $ / shares |  |  |  |  |  |  | $ 0.01 |  |  |  |  |
Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |
Common Stock, Aggregate Offering Price | $ |  |  |  |  |  |  |  |  |  |  | $ 75,000,000 |
Restricted Stock Units (RSUs) [Member] |  |  |  |  |  |  |  |  |  |  |  |
Allocated Share-based Compensation Expense, Total | $ |  |  |  |  | $ 7,000,000 |  |  |  |  |  |  |
Restricted Stock Units RSUs, Vesting In June 2019, June 2020, and June 2021 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period |  |  |  |  | 1,854,054 |  |  |  |  |  |  |
Restricted Stock Units RSUs, Vesting In June 2019, June 2020, and June 2021 [Member] | Share-based Compensation Award, Tranche One [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage |  |  |  |  | 33.00% |  |  |  |  |  |  |
Restricted Stock Units RSUs, Vesting In June 2019, June 2020, and June 2021 [Member] | Share-based Compensation Award, Tranche Two [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage |  |  |  |  | 33.00% |  |  |  |  |  |  |
Restricted Stock Units RSUs, Vesting In June 2019, June 2020, and June 2021 [Member] | Share-based Compensation Award, Tranche Three [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage |  |  |  |  | 33.00% |  |  |  |  |  |  |
Restricted Stock Units RSUs, Vesting in June 2019 and June 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period |  |  |  |  | 96,604 |  |  |  |  |  |  |
Restricted Stock Units RSUs, Vesting in June 2019 and June 2020 [Member] | Share-based Compensation Award, Tranche One [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage |  |  |  |  | 50.00% |  |  |  |  |  |  |
Restricted Stock Units RSUs, Vesting in June 2019 and June 2020 [Member] | Share-based Compensation Award, Tranche Two [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage |  |  |  |  | 50.00% |  |  |  |  |  |  |
Restricted Stock Units RSUs, Vesting in June 2019 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period |  |  |  |  | 28,721 |  |  |  |  |  |  |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options | $ |  |  |  |  | $ 2,500,000 |  |  |  |  |  |  |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition |  |  |  |  | 1 year |  |  |  |  |  |  |
Restricted Stock Units (RSUs) Vesting in June 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options | $ |  |  |  |  | $ 2,400,000 |  |  |  |  |  |  |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition |  |  |  |  | 2 years |  |  |  |  |  |  |
Restricted Stock Units (RSUs) Vesting in June 2021 [Member] |  |  |  |  |  |  |  |  |  |  |  |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options | $ |  |  |  |  | $ 2,200,000 |  |  |  |  |  |  |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition |  |  |  |  | 3 years |  |  |  |  |  |  |
Performance Shares [Member] |  |  |  |  |  |  |  |  |  |  |  |
Allocated Share-based Compensation Expense, Total | $ |  |  |  |  |  |  | $ 4,700,000 | $ 4,900,000 |  |  |  |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition |  |  |  |  | 2 years 180 days |  |  |  |  |  |  |

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- Definition The minimum average realized silver price per ounce that must be met for the silver-price-linked component of dividends to be declared. + References No definition available. + Details
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- Definition Measurement period used to value performance-based share awards. The value of the awards will be based on the ranking of the market performance of common stock relative to the performance of the common stock of a group of peer companies. + References No definition available. + Details
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- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5047-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition Number of securities into which each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares. + References No definition available. + Details
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- Definition Number of warrants or rights outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
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- Definition Aggregate dividends declared during the period for each share of common stock outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
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- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The amount of cash paid for brokerage fees during the current period. This element is intended to represent the brokerage fees paid by and between financial industry participants. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3536-108585 + Details
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- Definition Amount of cash outflow to satisfy an employee's income tax withholding obligation as part of a net-share settlement of a share-based award. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 25 -Paragraph 19A -URI http://asc.fasb.org/extlink&oid=107668666&loc=SL79513924-113897 + Details
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition Number of share instruments newly issued under a share-based compensation plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition Price of a single share of a number of saleable stocks of a company. + References No definition available. + Details
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- Definition Percentage of vesting of share-based compensation awards. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer. + References No definition available. + Details
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