Employee Stock Compensation Plans	9 Months Ended
Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Employee Stock Compensation Plans	8. Employee Stock Compensation Plans On June 18, 2013, Solitario’s shareholders approved the 2013 Solitario Exploration & Royalty Corp. Omnibus Stock and Incentive Plan (the “2013 Plan”). Under the terms of the 2013 Plan, a total of 1,750,000 shares of Solitario common stock were originally reserved for awards to directors, officers, employees and consultants. On June 29, 2017, Solitario shareholders approved an amendment to the 2013 Plan, which increased the number of shares of common stock available for issuance under the 2013 Plan from 1,750,000 to 5,750,000. Awards granted under the 2013 Plan may take the form of stock options, stock appreciation rights, restricted stock, and restricted stock units. The terms and conditions of the awards are pursuant to the 2013 Plan and are granted by the Board of Directors or a committee appointed by the Board of Directors. As of September 30, 2018, and December 31, 2017, there were options outstanding that are exercisable to acquire an aggregate of 4,025,228 and 1,928,428 shares of Solitario common stock, respectively. These options have exercise prices between $0.62 per share and $1.96 per share. Of these, as of September 30, 2018, 1,425,228 options are Replacement Options granted in connection with the Acquisition. During the nine months ended September 30, 2018, 357,200 Replacement Options with an exercise price of $2.24 per share expired unexercised. During the nine months ended September 30, 2018, Solitario granted options exercisable to acquire 100,000 shares of common stock to a consultant, with an exercise price of $0.62 per share, having a term of eleven months and having a grant date fair value of $12,000 based upon a Black-Scholes model with a 66% volatility and a 1% risk-free interest rate. During the three months ended September 30, 2017, Solitario granted options to acquire 2,500,000 shares of common stock, including 2,300,000 Conditional Options (described below). During the nine months ended September 30, 2017, Solitario granted options to acquire a total of 4,282,428 shares of common stock, including 1,782,428 Replacement Options. There were no exercises of options under the 2013 Plan during the three and nine months ended September 30, 2018 and 2017. During the three and nine months ended September 30, 2018, Solitario recorded non-cash stock option compensation expense of $68,000 and $510,000, respectively. Solitario recorded $23,000 of non-cash stock option compensation expense during the three and nine months ended September 30, 2017. On September 1, 2017, the Board of Directors granted, subject to shareholder approval at the next meeting of shareholders, 2,300,000 stock options under the 2013 Plan to officers and members of the Board of Directors (the “Conditional Options”). The Conditional Options were approved by Solitario’s shareholders at Solitario’s annual meeting on June 19, 2018. The Conditional Options have a five-year life, an exercise price of $0.77 per share, and a grant date fair value of $970,000, based upon a Black-Scholes model with a volatility of 64%, and a risk-free interest rate of 1.70%. The Conditional Options vest on the schedule of 25% on date of approval of the grant (June 19, 2018) and 25% on each of the next three anniversary dates of the date of grant (September 1, 2018, 2019 and 2020).

Employee Stock Compensation Plans

9 Months Ended

Sep. 30, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

8. Employee Stock Compensation Plans

On June 18, 2013, Solitario’s shareholders approved the 2013 Solitario Exploration & Royalty Corp. Omnibus Stock and Incentive Plan (the “2013 Plan”). Under the terms of the 2013 Plan, a total of 1,750,000 shares of Solitario common stock were originally reserved for awards to directors, officers, employees and consultants. On June 29, 2017, Solitario shareholders approved an amendment to the 2013 Plan, which increased the number of shares of common stock available for issuance under the 2013 Plan from 1,750,000 to 5,750,000. Awards granted under the 2013 Plan may take the form of stock options, stock appreciation rights, restricted stock, and restricted stock units. The terms and conditions of the awards are pursuant to the 2013 Plan and are granted by the Board of Directors or a committee appointed by the Board of Directors.

As of September 30, 2018, and December 31, 2017, there were options outstanding that are exercisable to acquire an aggregate of 4,025,228 and 1,928,428 shares of Solitario common stock, respectively. These options have exercise prices between $0.62 per share and $1.96 per share. Of these, as of September 30, 2018, 1,425,228 options are Replacement Options granted in connection with the Acquisition. During the nine months ended September 30, 2018, 357,200 Replacement Options with an exercise price of $2.24 per share expired unexercised. During the nine months ended September 30, 2018, Solitario granted options exercisable to acquire 100,000 shares of common stock to a consultant, with an exercise price of $0.62 per share, having a term of eleven months and having a grant date fair value of $12,000 based upon a Black-Scholes model with a 66% volatility and a 1% risk-free interest rate. During the three months ended September 30, 2017, Solitario granted options to acquire 2,500,000 shares of common stock, including 2,300,000 Conditional Options (described below). During the nine months ended September 30, 2017, Solitario granted options to acquire a total of 4,282,428 shares of common stock, including 1,782,428 Replacement Options. There were no exercises of options under the 2013 Plan during the three and nine months ended September 30, 2018 and 2017. During the three and nine months ended September 30, 2018, Solitario recorded non-cash stock option compensation expense of $68,000 and $510,000, respectively. Solitario recorded $23,000 of non-cash stock option compensation expense during the three and nine months ended September 30, 2017.

On September 1, 2017, the Board of Directors granted, subject to shareholder approval at the next meeting of shareholders, 2,300,000 stock options under the 2013 Plan to officers and members of the Board of Directors (the “Conditional Options”). The Conditional Options were approved by Solitario’s shareholders at Solitario’s annual meeting on June 19, 2018. The Conditional Options have a five-year life, an exercise price of $0.77 per share, and a grant date fair value of $970,000, based upon a Black-Scholes model with a volatility of 64%, and a risk-free interest rate of 1.70%. The Conditional Options vest on the schedule of 25% on date of approval of the grant (June 19, 2018) and 25% on each of the next three anniversary dates of the date of grant (September 1, 2018, 2019 and 2020).