Stock-Based Compensation

3 Months Ended

Jun. 30, 2018

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

The Company accounts for its stock-based compensation at fair value. The following table summarizes stock-based compensation expense by financial statement line item for the three months ended June 30, 2018 and 2017 (in thousands):



	Three months ended June 30,
	2018		2017
Cost of revenues	$	40	$	36
Research and development	51		49
Selling, general and administrative	694		669
Total	$	785	$	754

The Company issued 34,480 shares of immediately vested common stock and 276,000 shares of restricted stock awards during the three months ended June 30, 2018, and issued 33,487 shares of immediately vested common stock during the three months ended June 30, 2017. These restricted stock awards generally vest over 2-3 years. Awards for restricted stock include both time-based and performance-based awards. For options and awards that vest upon the passage of time, expense is being recorded over the vesting period. Performance-based awards are expensed over the requisite service period based on probability of achievement. In addition, the Company issued 16,667 restricted stock units under the 2007 Stock Incentive Plan during the three months ended June 30, 2017, each of which represents the right to receive one share of common stock in connection with a severance agreement entered into with one of the Company's former executive officers. These restricted stock units vested and were settled in shares of common stock on the eighth day after receipt of an irrevocable release.

The estimated fair value of the Company’s stock-based awards, less expected annual forfeitures, is amortized over the awards’ service period. The total unrecognized compensation cost for unvested outstanding stock options was $0.2 million at June 30, 2018. This expense will be recognized over a weighted average expense period of approximately 0.7 years. The total unrecognized compensation cost for unvested outstanding restricted stock was $3.5 million at June 30, 2018. This expense will be recognized over a weighted-average expense period of approximately 2.1 years.

The Company did not grant any stock options during the three months ended June 30, 2018 or 2017.