Stock Acquisition Rights, Stock Options and Warrants | 11. Stock Acquisition Rights, Stock Options and Warrants The Company established the 2014 Stock Plan (the “2014 Stock Plan”) to attract, retain and reward individuals who contribute to the achievement of the Company’s goals and objectives. This 2014 Stock Plan superseded previous stock plans although under such previous plans, 23,550 stock option shares were outstanding and vested as of September 30, 2019. The Company’s board of directors has reserved 3,805,223 shares of common stock for issuance under its 2014 Stock Plan as of September 30, 2019, of which 821,333 shares are available for future issuance. The number of shares will continue to automatically increase each January 1 through January 1, 2024 by an amount equal to the lesser of (i) 5% of the number of shares of common stock issued and outstanding on the immediately preceding December 31 or (ii) a lesser amount determined by the board of directors. Effective January 1, 2019, the board of directors elected to increase the shares authorized under the 2014 Stock Plan by 293,528 shares which represented 2% of the of the common stock issued and outstanding as of December 31, 2018.  Restricted Stock and Restricted Stock Units A summary of non-vested restricted stock activity for the six months ended September 30, 2019 is as follows:     Weighted  Average  Restricted Grant Day  Stock Fair Value  Non-vested restricted stock outstanding at March 31, 2019 279,212 $ 28.71  Granted 165,315 42.28  Forfeited (2,163) (22.85)  Vested (86,274) (28.41)  Non-vested restricted stock outstanding at September 30, 2019 356,090 $ 35.12  The Company recognizes compensation expense for restricted stock on a straight-line basis over the explicit vesting period. Vested restricted stock units are settled and issuable upon the earlier of the date the employee ceases to be an employee of the Company or a date certain in the future. Stock compensation expense related to restricted stock was approximately $1.0 million and $2.0 million for the three and six months ended September 30 , 2019 , respectively. Stock compensation expense related to restricted stock was approximately $1.4 million and $2.6 million for the three and six months ended September 30 , 2018 , respectively. In June 2018, the FASB issued ASU No. 2018-07, Compensation – Stock Compensation (Topic 718) – Improvements to Nonemployee Share-based Payment Accounting . ASU 2018-07 addresses several aspects of the accounting for nonemployee share-based payment transactions, including share-based payment transactions for acquiring goods and services from nonemployees. ASU 2018-07 is effective for the Company’s fiscal year 2020 beginning April 1, 2019. As a result of adopting the ASU on April 1, 2019, the Company reduced its accumulated deficit by $14,000 relating to restricted stock. Stock compensation expense for restricted stock is accounted for in general and administrative expense in the Company’s Consolidated Statement of Operations. At September 30, 2019, there was $10.5 million of unvested compensation expense for restricted stock, which is expected to be recognized over a weighted average period of 3.12 years. Performance Stock Units During the three and six months ended September 30, 2019, the Company did not award any performance stock units under the 2014 Stock Plan. Outstanding performance stock units represent the number of shares of the Company’s common stock that the recipient would receive upon the Company’s attainment of the applicable performance goals. The units will vest in full upon attainment, prior to January 13, 2020, of (A) a Final Order from the FCC providing for the creation and allocation of licenses for spectrum in the 900 MHz band consisting of paired blocks of contiguous spectrum, each containing at least 3 MHz of contiguous spectrum, authorized for broadband wireless communications uses and (B) the lack of objection by the Company's board of directors to the terms and conditions (including, but not limited to, the rebanding, clearing and relocation procedures, license assignment and award mechanisms, and technical and operational rules) set forth or referenced in the Final Order. These awards do not forfeit. A summary of the performance stock unit activity for the six months ended September 30, 2019 is as follows:     Weighted  Average  Performance Grant Day  Stock Fair Value  Performance stock outstanding at March 31, 2019 109,138 $ 23.80  Granted — —  Forfeited — —  Vested — —  Performance stock outstanding at September 30, 2019 109,138 $ 23.80 For the three and six months ended September 30 , 2019 and 2018, there was no stock compensation expense recognized for the performance units. At September 30, 2019, there was approximately $2.6 million of unvested compensation expense related to the outstanding performance stock units. Stock Options A summary of stock option activity for the six months ended September 30, 2019 is as follows:    Options Weighted Average Exercise Price  Options outstanding at March 31, 2019 1,923,634 $ 23.64  Options granted — —  Options exercised (89,323) (21.49)  Options forfeited/expired (9,875) (48.14)  Options outstanding at September 30, 2019 1,824,436 $ 23.61 There were no options granted for the three and six months ended September 30, 2019. Performance Stock Options A summary of the performance stock options as of September 30, 2019 is as follows:     Performance Options Weighted Average Exercise Price  Performance Options outstanding at March 31, 2019 179,945 $ 25.83  Performance Options granted — —  Performance Options exercised — —  Performance Options forfeited/expired — —  Performance Options outstanding at September 30, 2019 179,945 $ 25.83  The performance options will vest in full immediately upon attainment of the performance goals. Performance is based upon the Company’s achievement, prior to January 13, 2020, of (A) a Final Order from the FCC providing for the creation and allocation of licenses for spectrum in the 900 MHz band consisting of paired blocks of contiguous spectrum, each containing at least 3 MHz of contiguous spectrum, authorized for broadband wireless communications uses and (B) the lack of objection by the Company's Board of Directors to the terms and conditions (including, but not limited to, the rebanding, clearing and relocation procedures, license assignment and award mechanisms, and technical and operational rules) set forth or referenced in the Final Order. Stock compensation expense related to the amortization of the fair value of stock options (other than the performance stock options) issued was approximately $0.4 million and $1.0 million for the three and six months ended September 30, 2019 . For the three and six months ended September 30, 2018, the comparable stock compensation expense was approximately $2.1 million and $4.8 million, respectively, which included $1.1 million of expense related to the consulting and transition agreements and $2.1 million of expense related to the modification of option grants held by the Company’s former c hief e xecutive o fficer and p resident. The stock compensation expense is included in general and administrative expense in the accompanying Consolidated Statement of Operations. In June 2018, the FASB issued ASU No. 2018-07, Compensation – Stock Compensation (Topic 718) – Improvements to Nonemployee Share-based Payment Accounting . ASU 2018-07 addresses several aspects of the accounting for nonemployee share-based payment transactions, including share-based payment transactions for acquiring goods and services from nonemployees. ASU 2018-07 is effective for the Company’s fiscal year 2020 beginning April 1, 2019. As a result of adopting the ASU on April 1, 2019, the Company reduced its accumulated deficit by $174,000 relating to stock options. As of September 30, 2019 , there was approximately $3.1 million of unrecognized compensation cost related to non-vested stock options granted under the Company’s stock option plans , of which $2.0 million pertains to the non-performance based stock options which is expected to be recognized over a weighted-average period of 2.2 years. Motorola Investment On September 15, 2014, Motorola invested $10.0 million to purchase 500,000 Class B Units of the Company’s subsidiary, PDV Spectrum Holding Company, LLC (at a price equal to $20.00 per unit). The Company owns 100% of the Class A Units in this subsidiary. Motorola has the right at any time to convert its 500,000 Class B Units into 500,000 shares of the Company’s common stock. The Company also has the right to force Motorola’s conversion of these Class B Units into shares of its common stock at its election. Motorola is not entitled to any assets, profits or distributions from the operations of the subsidiary. In addition, Motorola’s conversion ratio from Class B Units to shares of the Company’s common stock is fixed on a one -for-one basis, and is not dependent on the performance or valuation of either the Company or the subsidiary. The Class B Units have no redemption or call provisions and can only be converted into shares of the Company’s common stock. Management has determined that this investment does not meet the criteria for temporary equity or non-controlling interest due to the limited rights that Motorola has as a holder of Class B Units, and accordingly has presented this investment as part of its permanent equity within Additional Paid-in Capital in the accompanying consolidated financial statements. |