Stock Compensation	9 Months Ended
Sep. 30, 2020
Stock Compensation [Abstract]
Stock Compensation	11. Stock compensation Under various share-based compensation plans, PSB grants non-qualified options to purchase the Company’s common shares at a price not less than fair value on the date of grant, as well as RSUs, to certain directors, officers and key employees. The service period for stock options and RSUs begins when (i) the Company and the recipient reach a mutual understanding of the key terms of the award, (ii) the award has been authorized, (iii) the recipient is affected by changes in the market price of our stock and (iv) it is probable that any performance conditions will be met, and ends when the stock options or RSUs vest. We account for forfeitures of share-based payments as they occur by reversing previously amortized share-based compensation expense with respect to grants that are forfeited in the period the employee terminates employment. We amortize the fair value of awards starting at the beginning of the service period as compensation expense. For awards that are earned solely upon the passage of time and continued service, the entire cost of the award is amortized on a straight-line basis over the service period. For awards with performance conditions, the individual cost of each vesting is amortized separately over each individual service period (the “accelerated attribution” method). In August 2020, the Company announced that Maria Hawthorne was retiring from her role as President and Chief Executive Officer (“CEO”) effective September 1, 2020 and would continue to serve as a Director of the Company. Due to Ms. Hawthorne’s continued service as a Director of the Company, her unvested stock option and restricted stock units will continue to vest on their original vesting schedule in accordance with the Company’s 2012 Equity and Performance-Based Incentive Compensation Plan and related award agreements. For financial reporting purposes, the end of the service periods for these stock option and restricted stock unit grants have changed from the various respective vesting dates to September 1, 2020, the date of her retirement as President and CEO. Accordingly, all remaining stock compensation expense for Ms. Hawthorne, which totaled $1.7 million, was amortized and included in general and administrative expense during the three and nine months ended September 30, 2020. Stock Options Stock options expire 10 years after the grant date and the exercise price is equal to the closing trading price of our common shares on the grant date. Stock option holders cannot require the Company to settle their award in cash. We use the Black-Scholes option valuation model to estimate the fair value of our stock options on the date of grant. For the three and nine months ended September 30, 2020, we recorded $0.1 million and $0.3 million, respectively, in compensation expense related to stock options as compared to $0.1 million and $0.2 million for the same periods in 2019, respectively. During the nine months ended September 30, 2020, 18,000 stock options were granted, 4,136 options were exercised and no options were forfeited. A total of 171,694 and 157,830 options were outstanding at September 30, 2020 and December 31, 2019, respectively. Restricted Stock Units RSUs granted prior to 2016 are subject to a six-year vesting, with 20% vesting after year two, and 20% vesting after each of the next four years. RSUs granted during and subsequent to 2016 are subject to a five-year vesting at the rate of 20% per year. The grantee receives dividends for each outstanding RSU equal to the per share dividend received by common shareholders. We expense any dividends previously paid upon forfeiture of the related RSU. Upon vesting, the grantee receives common shares equal to the number of vested RSUs, less common shares withheld in exchange for tax withholdings made by the Company to satisfy the grantee’s statutory tax liabilities arising from the vesting. The fair value of our RSUs is determined based upon the applicable closing trading price of our common shares on the date of grant. In March 2020, the Compensation Committee of the Board approved an annual performance-based equity incentive plan (“2020 Incentive Program”). Under the Program, certain employees will be eligible to receive RSUs subject to the Company’s achievement of pre-established performance metrics based on growth in (i) net asset value per share, and (ii) Total Shareholder Value, each as computed pursuant to the terms of the 2020 Incentive Program. In the event the pre-established targets are achieved, eligible employees will receive the target award, except that the Compensation Committee of the Board may adjust the actual award to 75% to 125% of the target award based on the their assessment of whether certain strategic and operational goals were accomplished in the performance period. RSUs related to the 2020 Incentive Program will be awarded on or around March 1 of the subsequent year. RSUs awarded under the 2020 Incentive Program will vest in five equal installments, with the first installment vesting on the award date. RSU holders will earn dividend equivalent rights during the vesting period. During the three and nine months ended September 30, 2020, management determined that it was not probable that the targets under the 2020 Incentive Program would be met due to the negative impact of the COVID-19 pandemic, and, as such, the Company did not record stock compensation expense related to the 2020 Incentive Program. For the three and nine months ended September 30, 2020, respectively, we recorded $2.2 million and $3.5 million in compensation expense related to RSUs as compared to $0.8 million and $2.5 million for the same periods in 2019. During the nine months ended September 30, 2020, 100 RSUs were granted, 70,576 RSUs vested and 1,920 RSUs were forfeited. Tax withholdings totaling $4.1 million were made on behalf of employees in exchange for 28,877 common shares withheld upon vesting for the nine months ended September 30, 2020 resulting in the issuance of 41,699 common shares. Tax withholdings totaling $6.1 million were made on behalf of employees in exchange for 38,961 common shares withheld upon vesting for the nine months ended September 30, 2019 resulting in the issuance of 53,859 common shares. A total of 78,452 and 150,848 RSUs were outstanding at September 30, 2020 and December 31, 2019, respectively. In July 2019, the Company amended the Retirement Plan for Non-Employee Directors (the “Director Retirement Plan”), to increase the maximum shares issued upon retirement for each year served as a director from 8,000 shares to 10,000 shares of common stock. The Company recognizes compensation expense with regard to grants to be issued in the future under the Director Retirement Plan over the requisite service period. For the three and nine months ended September 30, 2020, respectively, we recorded $0.2 million and $0.6 million in compensation expense related to these shares as compared to $1.2 million and $1.3 million for the same periods in 2019. In April 2019, we issued 8,000 shares of common stock to a director upon retirement with an aggregate fair value of $1.2 million. Compensation expense for these shares was previously expensed. No director retirement shares were issued during the nine months ended September 30, 2020.

11. Stock compensation

Under various share-based compensation plans, PSB grants non-qualified options to purchase the Company’s common shares at a price not less than fair value on the date of grant, as well as RSUs, to certain directors, officers and key employees.

The service period for stock options and RSUs begins when (i) the Company and the recipient reach a mutual understanding of the key terms of the award, (ii) the award has been authorized, (iii) the recipient is affected by changes in the market price of our stock and (iv) it is probable that any performance conditions will be met, and ends when the stock options or RSUs vest.

We account for forfeitures of share-based payments as they occur by reversing previously amortized share-based compensation expense with respect to grants that are forfeited in the period the employee terminates employment.

We amortize the fair value of awards starting at the beginning of the service period as compensation expense. For awards that are earned solely upon the passage of time and continued service, the entire cost of the award is amortized on a straight-line basis over the service period. For awards with performance conditions, the individual cost of each vesting is amortized separately over each individual service period (the “accelerated attribution” method).

In August 2020, the Company announced that Maria Hawthorne was retiring from her role as President and Chief Executive Officer (“CEO”) effective September 1, 2020 and would continue to serve as a Director of the Company. Due to Ms. Hawthorne’s continued service as a Director of the Company, her unvested stock option and restricted stock units will continue to vest on their original vesting schedule in accordance with the Company’s 2012 Equity and Performance-Based Incentive Compensation Plan and related award agreements. For financial reporting purposes, the end of the service periods for these stock option and restricted stock unit grants have changed from the various respective vesting dates to September 1, 2020, the date of her retirement as President and CEO. Accordingly, all remaining stock compensation expense for Ms. Hawthorne, which totaled $1.7 million, was amortized and included in general and administrative expense during the three and nine months ended September 30, 2020.

Stock Options

Stock options expire 10 years after the grant date and the exercise price is equal to the closing trading price of our common shares on the grant date. Stock option holders cannot require the Company to settle their award in cash. We use the Black-Scholes option valuation model to estimate the fair value of our stock options on the date of grant.

For the three and nine months ended September 30, 2020, we recorded $0.1 million and $0.3 million, respectively, in compensation expense related to stock options as compared to $0.1 million and $0.2 million for the same periods in 2019, respectively.

During the nine months ended September 30, 2020, 18,000 stock options were granted, 4,136 options were exercised and no options were forfeited. A total of 171,694 and 157,830 options were outstanding at September 30, 2020 and December 31, 2019, respectively.

Restricted Stock Units

RSUs granted prior to 2016 are subject to a six-year vesting, with 20% vesting after year two, and 20% vesting after each of the next four years. RSUs granted during and subsequent to 2016 are subject to a five-year vesting at the rate of 20% per year. The grantee receives dividends for each outstanding RSU equal to the per share dividend received by common shareholders. We expense any dividends previously paid upon forfeiture of the related RSU. Upon vesting, the grantee receives common shares equal to the number of vested RSUs, less common shares withheld in exchange for tax withholdings made by the Company to satisfy the grantee’s statutory tax liabilities arising from the vesting. The fair value of our RSUs is determined based upon the applicable closing trading price of our common shares on the date of grant.

In March 2020, the Compensation Committee of the Board approved an annual performance-based equity incentive plan (“2020 Incentive Program”). Under the Program, certain employees will be eligible to receive RSUs subject to the Company’s achievement of pre-established performance metrics based on growth in (i) net asset value per share, and (ii) Total Shareholder Value, each as computed pursuant to the terms of the 2020 Incentive Program. In the event the pre-established targets are achieved, eligible employees will receive the target award, except that the Compensation Committee of the Board may adjust the actual award to 75% to 125% of the target award based on the their assessment of whether certain strategic and operational goals were accomplished in the performance period. RSUs related to the 2020 Incentive Program will be awarded on or around March 1 of the subsequent year. RSUs awarded under the 2020 Incentive Program will vest in five equal installments, with the first installment vesting on the award date. RSU holders will earn dividend equivalent rights during the vesting period.

During the three and nine months ended September 30, 2020, management determined that it was not probable that the targets under the 2020 Incentive Program would be met due to the negative impact of the COVID-19 pandemic, and, as such, the Company did not record stock compensation expense related to the 2020 Incentive Program.

For the three and nine months ended September 30, 2020, respectively, we recorded $2.2 million and $3.5 million in compensation expense related to RSUs as compared to $0.8 million and $2.5 million for the same periods in 2019.

During the nine months ended September 30, 2020, 100 RSUs were granted, 70,576 RSUs vested and 1,920 RSUs were forfeited. Tax withholdings totaling $4.1 million were made on behalf of employees in exchange for 28,877 common shares withheld upon vesting for the nine months ended September 30, 2020 resulting in the issuance of 41,699 common shares. Tax withholdings totaling $6.1 million were made on behalf of employees in exchange for 38,961 common shares withheld upon vesting for the nine months ended September 30, 2019 resulting in the issuance of 53,859 common shares. A total of 78,452 and 150,848 RSUs were outstanding at September 30, 2020 and December 31, 2019, respectively.

In July 2019, the Company amended the Retirement Plan for Non-Employee Directors (the “Director Retirement Plan”), to increase the maximum shares issued upon retirement for each year served as a director from 8,000 shares to 10,000 shares of common stock. The Company recognizes compensation expense with regard to grants to be issued in the future under the Director Retirement Plan over the requisite service period. For the three and nine months ended September 30, 2020, respectively, we recorded $0.2 million and $0.6 million in compensation expense related to these shares as compared to $1.2 million and $1.3 million for the same periods in 2019.

In April 2019, we issued 8,000 shares of common stock to a director upon retirement with an aggregate fair value of $1.2 million. Compensation expense for these shares was previously expensed. No director retirement shares were issued during the nine months ended September 30, 2020.