Stockholders' Equity	9 Months Ended
Sep. 30, 2018
Stockholders' Equity [Abstract]
Stockholders' Equity	Note 9 - Stockholders’ Equity Authorized and Issued Capital Stock Effective March 15, 2017, and pursuant to a reverse stock split approved by the stockholders and Board of Directors, each 20 shares of issued and outstanding common stock became one share of common stock and no fractional shares were issued. References to the number of shares and price per share give retroactive effect to the reverse stock split for all periods presented. As of September 30, 2018, we had 35.0 million shares of common stock authorized with a par value of $0.01 per share, of which approximately 7.7 million were issued and outstanding, and 1.0 million shares of preferred stock authorized with a par value of $0.01 per share. On April 6, 2018, the Company entered into a preferred stock purchase agreement with Yorktown for a private placement of 50,000 shares of the Preferred Stock for $5.0 million. During the nine months ended September 30, 2018, the increase in our issued and outstanding common stock is primarily due to (a) Yorktown’s exercise of the California Warrant (see note 3), resulting in the issuance of approximately 1.5 million shares of our common stock in exchange for Class A Units in Carbon California representing approximately 46.96% of the then outstanding Class A Units, in addition to (b) restricted stock and restricted performance units that vested during the year. Carbon Stock Incentive Plans We have two stock plans, the Carbon 2011 Stock Incentive Plan and the Carbon 2015 Stock Incentive Plan (collectively the “Carbon Plans”). The Carbon Plans were approved by our shareholders and in the aggregate provide for the issuance of approximately 1.1 million shares of common stock to our officers, directors, employees or consultants eligible to receive the awards under the Carbon Plans. The Carbon Plans provide for the granting of incentive stock options, non-qualified stock options, restricted stock awards, performance awards and phantom stock awards, or a combination of the foregoing, as to employees, officers, directors or consultants, provided that only employees may be granted incentive stock options and directors may only be granted restricted stock awards and phantom stock awards. Restricted Stock As of September 30, 2018, approximately 649,000 shares of restricted stock have been granted under the terms of the Carbon Plans. Restricted stock awards for employees vest ratably over a three-year service period or cliff vest at the end of a three-year service period. For non-employee directors, the awards vest upon the earlier of a change in control of us or the date their membership on the Board of Directors is terminated other than for cause. We recognize compensation expense for these restricted stock grants based on the grant date fair value of the shares, amortized ratably over three years for employee awards (based on the required service period for vesting) and seven years for non-employee director awards (based on a market survey of the average tenure of directors among U.S. public companies). For restricted stock granted between 2014 and 2017, we recognized compensation expense based on the grant date fair value of the shares, utilizing an enterprise value approach, using valuation metrics primarily based on multiples of cash flow from operations, production and reserves. For restricted stock and performance units granted in 2013 and 2018, we utilized the closing price of our stock on the date of grant to recognize compensation expense. During the nine months ended September 30, 2018, approximately 59,000 restricted stock units vested. Compensation costs recognized for these restricted stock grants were approximately $189,000 and $537,000 for the three and nine months ended September 30, 2018, respectively. For the three and nine months ended September 30, 2017, we recognized compensation expense of approximately $160,000 and $513,000, respectively. As of September 30, 2018, there was approximately $1.6 million unrecognized compensation costs related to these restricted stock grants which we expect to be recognized over the next 6.5 years. In 2018 we utilized the traded value of our common stock on the date of grant instead of the enterprise value to record compensation expense related to new equity grants. Due to the price received for our Preferred Stock, we believe the closing price of our common stock is now a better representation of the fair value of our common stock, instead of the enterprise value used to record compensation expense related to new equity grants. Restricted Performance Units As of September 30, 2018, approximately 597,000 shares of performance units have been granted under the terms of the Carbon Plans. Performance units represent a contractual right to receive one share of our common stock subject to the terms and conditions of the agreements, including the achievement of certain performance measures relative to a defined peer group or the growth of certain performance measures over a defined period of time as well as, in some cases, continued service requirements. We account for the performance units granted during 2014 through 2018 at their fair value determined at the date of grant, which were $11.80, $8.00, $5.40, $7.20 and $9.80 per share, respectively. The final measurement of compensation cost will be based on the number of performance units that ultimately vest. At September 30, 2018, we estimated that none of the performance units granted in 2016-2018 would vest, and, accordingly, no compensation cost has been recorded for these performance units. During 2016, we estimated that it was probable that the performance units granted in 2014 and 2015 would vest and therefore compensation costs of approximately $135,000 and $239,000 related to these performance units were recognized for the nine months ended September 30, 2018 and 2017, respectively. As of September 30, 2018, compensation costs related to the performance units granted in 2014 and 2015 have been fully recognized. As of September 30, 2018, if change in control and other performance provisions pursuant to the terms and conditions of these award agreements are met in full, the estimated unrecognized compensation cost related to the performance units granted in 2012 and 2016 through 2018 would be approximately $3.3 million. *Preferred Stock* Series B Convertible Preferred Stock – Related Party In connection with the closing of the Seneca Acquisition, we raised $5.0 million through the issuance of 50,000 shares of Preferred Stock to Yorktown. The Preferred Stock converts into common stock at the election of the holder or will automatically convert into shares of our common stock upon completion of a qualifying equity financing event. The number of shares of common stock issuable upon conversion is dependent upon the price per share of common stock issued in connection with any such qualifying equity financing but has a floor conversion price equal to $8.00 per share. The conversion ratio at which the Preferred Stock will convert into common stock is equal to an amount per share of $100 plus all accrued but unpaid dividends payable in respect thereof divided by the greater of (i) $8.00 per share or (ii) the price that is 15% less than the lowest price per share of shares sold to the public in the next equity financing. Using the floor of $8.00 per share would yield 12.5 shares of common stock for every unit of Preferred Stock. The conversion price will be proportionately increased or decreased to reflect changes to the outstanding shares of common stock, such as the result of a combination, reclassification, subdivision, stock split, stock dividend or other similar transaction involving the common stock. Additionally, after the third anniversary of the issuance of the Preferred Stock, we have the option to redeem the shares for cash. The Preferred Stock accrues cash dividends at a rate of six percent (6%) of the initial issue price of $100 per share per annum. The holders of the Preferred Stock are entitled to the same number of votes of common stock that such share of Preferred Stock would represent on an as converted basis. The holders of the Preferred Stock receive liquidation preference based on the initial issue price of $100 per share plus any accrued dividends over common stock holders and the holders of any junior ranking stock. As of September 30, 2018, we accrued $147,000 of dividends. We apply the guidance in ASC 480 “Distinguishing Liabilities from Equity” when determining the classification and measurement of the Preferred Stock. The Preferred Stock does not feature any redemption rights within the holders’ control or conditional redemption features not within our control as of September 30, 2018. Accordingly, the Preferred Stock is presented as a component of consolidated stockholders’ equity. We have evaluated the Preferred Stock in accordance with ASC 815, “Derivatives and Hedging”, including consideration of embedded derivatives requiring bifurcation. The issuance of the Preferred Stock could generate a beneficial conversion feature (“BCF”), which arises when a debt or equity security is issued with an embedded conversion option that is beneficial to the investor or in the money at inception because the conversion option has an effective strike price that is less than the market price of the underlying stock at the commitment date. Based on the conversion terms and the price at the commitment date, we determined that a BCF was required to be recorded related to the voluntary conversion option by the holder as of September 30, 2018. We recorded the BCF as a reduction of retained earnings and an increase to APIC of $1.1 million, which is based on the difference between the floor price of $8.00 and our stock price as of the commitment date multiplied by the number of shares to be issued. We are also required to evaluate a contingent BCF for the automatic conversion feature, but in accordance with ASC 470, “Debt”, we will not record the effect of the BCF until the contingency is resolved. As of September 30, 2018, we have a BCF of approximately $1.1 million.

Note 9 - Stockholders’ Equity

Authorized and Issued Capital Stock

Effective March 15, 2017, and pursuant to a reverse stock split approved by the stockholders and Board of Directors, each 20 shares of issued and outstanding common stock became one share of common stock and no fractional shares were issued. References to the number of shares and price per share give retroactive effect to the reverse stock split for all periods presented.

As of September 30, 2018, we had 35.0 million shares of common stock authorized with a par value of $0.01 per share, of which approximately 7.7 million were issued and outstanding, and 1.0 million shares of preferred stock authorized with a par value of $0.01 per share. On April 6, 2018, the Company entered into a preferred stock purchase agreement with Yorktown for a private placement of 50,000 shares of the Preferred Stock for $5.0 million. During the nine months ended September 30, 2018, the increase in our issued and outstanding common stock is primarily due to (a) Yorktown’s exercise of the California Warrant (see note 3), resulting in the issuance of approximately 1.5 million shares of our common stock in exchange for Class A Units in Carbon California representing approximately 46.96% of the then outstanding Class A Units, in addition to (b) restricted stock and restricted performance units that vested during the year.

Carbon Stock Incentive Plans

We have two stock plans, the Carbon 2011 Stock Incentive Plan and the Carbon 2015 Stock Incentive Plan (collectively the “Carbon Plans”). The Carbon Plans were approved by our shareholders and in the aggregate provide for the issuance of approximately 1.1 million shares of common stock to our officers, directors, employees or consultants eligible to receive the awards under the Carbon Plans.

The Carbon Plans provide for the granting of incentive stock options, non-qualified stock options, restricted stock awards, performance awards and phantom stock awards, or a combination of the foregoing, as to employees, officers, directors or consultants, provided that only employees may be granted incentive stock options and directors may only be granted restricted stock awards and phantom stock awards.

Restricted Stock

As of September 30, 2018, approximately 649,000 shares of restricted stock have been granted under the terms of the Carbon Plans. Restricted stock awards for employees vest ratably over a three-year service period or cliff vest at the end of a three-year service period. For non-employee directors, the awards vest upon the earlier of a change in control of us or the date their membership on the Board of Directors is terminated other than for cause. We recognize compensation expense for these restricted stock grants based on the grant date fair value of the shares, amortized ratably over three years for employee awards (based on the required service period for vesting) and seven years for non-employee director awards (based on a market survey of the average tenure of directors among U.S. public companies). For restricted stock granted between 2014 and 2017, we recognized compensation expense based on the grant date fair value of the shares, utilizing an enterprise value approach, using valuation metrics primarily based on multiples of cash flow from operations, production and reserves. For restricted stock and performance units granted in 2013 and 2018, we utilized the closing price of our stock on the date of grant to recognize compensation expense. During the nine months ended September 30, 2018, approximately 59,000 restricted stock units vested.

Compensation costs recognized for these restricted stock grants were approximately $189,000 and $537,000 for the three and nine months ended September 30, 2018, respectively. For the three and nine months ended September 30, 2017, we recognized compensation expense of approximately $160,000 and $513,000, respectively. As of September 30, 2018, there was approximately $1.6 million unrecognized compensation costs related to these restricted stock grants which we expect to be recognized over the next 6.5 years. In 2018 we utilized the traded value of our common stock on the date of grant instead of the enterprise value to record compensation expense related to new equity grants. Due to the price received for our Preferred Stock, we believe the closing price of our common stock is now a better representation of the fair value of our common stock, instead of the enterprise value used to record compensation expense related to new equity grants.

Restricted Performance Units

As of September 30, 2018, approximately 597,000 shares of performance units have been granted under the terms of the Carbon Plans. Performance units represent a contractual right to receive one share of our common stock subject to the terms and conditions of the agreements, including the achievement of certain performance measures relative to a defined peer group or the growth of certain performance measures over a defined period of time as well as, in some cases, continued service requirements.

We account for the performance units granted during 2014 through 2018 at their fair value determined at the date of grant, which were $11.80, $8.00, $5.40, $7.20 and $9.80 per share, respectively. The final measurement of compensation cost will be based on the number of performance units that ultimately vest. At September 30, 2018, we estimated that none of the performance units granted in 2016-2018 would vest, and, accordingly, no compensation cost has been recorded for these performance units. During 2016, we estimated that it was probable that the performance units granted in 2014 and 2015 would vest and therefore compensation costs of approximately $135,000 and $239,000 related to these performance units were recognized for the nine months ended September 30, 2018 and 2017, respectively. As of September 30, 2018, compensation costs related to the performance units granted in 2014 and 2015 have been fully recognized. As of September 30, 2018, if change in control and other performance provisions pursuant to the terms and conditions of these award agreements are met in full, the estimated unrecognized compensation cost related to the performance units granted in 2012 and 2016 through 2018 would be approximately $3.3 million.

Preferred Stock

Series B Convertible Preferred Stock – Related Party

In connection with the closing of the Seneca Acquisition, we raised $5.0 million through the issuance of 50,000 shares of Preferred Stock to Yorktown. The Preferred Stock converts into common stock at the election of the holder or will automatically convert into shares of our common stock upon completion of a qualifying equity financing event. The number of shares of common stock issuable upon conversion is dependent upon the price per share of common stock issued in connection with any such qualifying equity financing but has a floor conversion price equal to $8.00 per share. The conversion ratio at which the Preferred Stock will convert into common stock is equal to an amount per share of $100 plus all accrued but unpaid dividends payable in respect thereof divided by the greater of (i) $8.00 per share or (ii) the price that is 15% less than the lowest price per share of shares sold to the public in the next equity financing. Using the floor of $8.00 per share would yield 12.5 shares of common stock for every unit of Preferred Stock. The conversion price will be proportionately increased or decreased to reflect changes to the outstanding shares of common stock, such as the result of a combination, reclassification, subdivision, stock split, stock dividend or other similar transaction involving the common stock. Additionally, after the third anniversary of the issuance of the Preferred Stock, we have the option to redeem the shares for cash.

The Preferred Stock accrues cash dividends at a rate of six percent (6%) of the initial issue price of $100 per share per annum. The holders of the Preferred Stock are entitled to the same number of votes of common stock that such share of Preferred Stock would represent on an as converted basis. The holders of the Preferred Stock receive liquidation preference based on the initial issue price of $100 per share plus any accrued dividends over common stock holders and the holders of any junior ranking stock. As of September 30, 2018, we accrued $147,000 of dividends.

We apply the guidance in ASC 480 “Distinguishing Liabilities from Equity” when determining the classification and measurement of the Preferred Stock. The Preferred Stock does not feature any redemption rights within the holders’ control or conditional redemption features not within our control as of September 30, 2018. Accordingly, the Preferred Stock is presented as a component of consolidated stockholders’ equity.

We have evaluated the Preferred Stock in accordance with ASC 815, “Derivatives and Hedging”, including consideration of embedded derivatives requiring bifurcation. The issuance of the Preferred Stock could generate a beneficial conversion feature (“BCF”), which arises when a debt or equity security is issued with an embedded conversion option that is beneficial to the investor or in the money at inception because the conversion option has an effective strike price that is less than the market price of the underlying stock at the commitment date. Based on the conversion terms and the price at the commitment date, we determined that a BCF was required to be recorded related to the voluntary conversion option by the holder as of September 30, 2018. We recorded the BCF as a reduction of retained earnings and an increase to APIC of $1.1 million, which is based on the difference between the floor price of $8.00 and our stock price as of the commitment date multiplied by the number of shares to be issued. We are also required to evaluate a contingent BCF for the automatic conversion feature, but in accordance with ASC 470, “Debt”, we will not record the effect of the BCF until the contingency is resolved. As of September 30, 2018, we have a BCF of approximately $1.1 million.