Stock-based compensation

6 Months Ended

Jun. 30, 2020

Share-based Payment Arrangement [Abstract]

Restricted Stock Units

The Company grants restricted stock units under compensation arrangements for the benefit of employees, executive officers, and directors. Restricted stock unit grants are subject to time-based vesting. The total number of restricted stock units granted represents the maximum number of restricted stock units eligible to vest based upon the service conditions set forth in the grant agreements.

The following table summarizes information about vested and unvested restricted stock units as of the dates indicated:


	Six Months Ended June 30,
	2020				2019
	Restricted Stock Units Outstanding	Weighted Average Grant Date Fair Value		Restricted Stock Units Outstanding	Weighted Average Grant Date Fair Value
Balance at beginning of period	826,263	$	23.76	1,140,215	$	21.96
Grants	132,605	33.92		165,761	34.03
Released and distributed (vested)	(132,203)	32.52		(195,755)	25.62
Forfeited/expired	(14,826)	34.24		(9,581)	24.72
Balance at end of period	811,839	$	24.84	1,100,640	$	25.53

The total fair value of restricted stock units vested and released was $1,048 and $4,299 for the three and six months ended June 30, 2020, respectively, and $482 and $5,015 for the three and six months ended June 30, 2019, respectively.

The compensation cost related to stock grants and vesting of restricted stock units was $2,015 and $3,817 for the three and six months ended June 30, 2020, respectively, and $2,147 and $3,785 for the three and six months ended June 30, 2019, respectively. This included $231 and $378 paid to Company independent directors during the three and six months ended June 30, 2020, respectively, and $179 and $351 during the three and six months ended June 30, 2019, respectively, related to independent director grants and compensation elected to be settled in stock.

As of June 30, 2020 and December 31, 2019, there were $10,810 and $11,499, respectively, of total unrecognized compensation cost related to unvested restricted stock units which is expected to be recognized over a weighted-average period of 2.21 years and 2.00 years, respectively. At June 30, 2020 and December 31, 2019, there were $452 and $375, respectively, accrued in other liabilities related to dividends declared to be paid upon vesting and distribution of the underlying RSUs.

Performance Based Restricted Stock Units:

During 2020, the Company began awarding performance-based restricted stock units ("PSUs") to executives and other officers and employees. Under the terms of the award, the number of units that will vest and convert to shares of common stock will be based on the extent to which the Company achieves specified performance criteria during the fixed three-year performance period. The number of shares issued upon vesting will range from 0% to 200% of the PSUs granted. The PSUs vest at the end of a three-year period based on average adjusted return on tangible equity as reported, adjusted for unusual gains/losses, merger expenses, and other items as approved by the compensation committee of the Company's board of directors. Compensation expense for the PSUs will be estimated each period based on the fair value of the stock at the grant date and the most probable outcome of the performance condition, adjusted for the passage of time within the vesting period of the awards.

The Company granted 53,147 shares of performance based restricted stock units and recorded compensation cost of $335 and $416 during the three and six months ended June 30, 2020, respectively. As of June 30, 2020, the Company determined the probability of meeting the performance criteria, and recorded compensation cost associated with a 181% vesting, when factoring in the conversion of PSUs to shares of common stock. As of June 30, 2020, maximum unrecognized compensation cost related to the nonvested PSUs was $3,067, and the remaining performance period over which the cost could be recognized was 2.64 years.

Employee Stock Purchase Plan:

The Company maintains an employee stock purchase plan (“ESPP”) under which employees, through payroll deductions, are able to purchase shares of Company common stock. The purchase price is 95% of the lower of the market price on the first or last day of the offering period. The maximum number of shares issuable during any offering period is 200,000 shares and a participant may not purchase more than 725 shares during any offering period (and, in any event, no more than $25 worth of common stock in any calendar year). There were no shares issued under the ESPP during the three months ended June 30, 2020 and 2019, respectively. During the six months ended June 30, 2020 and 2019, there were 12,145 and 10,613 shares of common stock issued under the ESPP, respectively. As of June 30, 2020 and December 31, 2019, there were 2,397,040 and 2,409,185 shares available for issuance under the ESPP, respectively.