STOCKHOLDERS' EQUITY

9 Months Ended

Sep. 30, 2019

Recent Developments

In the nine months ended September 30, 2019, we completed a public issuance of 3,565 shares of our Class A common stock at a public offering price of $29.50 per share. The offering resulted in net proceeds to us of $100,446, after deducting underwriting discounts and commissions and offering expenses. The net proceeds from the offering were and are to be used for general corporate purposes, including potential acquisitions or development of new operations or assets with the goal of complementing or expanding our business, working capital and capital expenditures.

In the three and nine months ended September 30, 2019, we completed the unregistered sale of 59 shares of our Class A common stock at a price of $44.15 per share. The sale resulted in net proceeds to us of $2,618. The shares were previously held in escrow according to the terms of our acquisition of WSI and released to us for liquidation to offset costs associated with the environmental remediation of the WSI's Potsdam, New York site. We recorded a $2,618 reduction of goodwill in line with business combination standards in place at the time the shares held in escrow were issued. See Note 9, Commitments and Contingencies for additional disclosure.

Stock Based Compensation

Shares Available For Issuance

In the fiscal year ended December 31, 2016, we adopted the 2016 Incentive Plan (“2016 Plan”). Under the 2016 Plan, we may grant awards up to an aggregate amount of shares equal to the sum of: (i) 2,250 shares of Class A common stock (subject to adjustment in the event of stock splits and other similar events), plus (ii) such additional number of shares of Class A common stock (up to 2,723 shares) as is equal to the sum of the number of shares of Class A common stock that remained available for grant under the 2006 Stock Incentive Plan (“2006 Plan”) immediately prior to the expiration of the 2006 Plan and the number of shares of Class A common stock subject to awards granted under the 2006 Plan that expire, terminate or are otherwise surrendered, canceled, forfeited or repurchased by us. As of September 30, 2019, there were 1,399 Class A common stock equivalents available for future grant under the 2016 Plan.

Stock Options

Stock options are granted at a price equal to the prevailing fair value of our Class A common stock at the date of grant. Generally, stock options granted have a term not to exceed ten years and vest over a one year to four year period from the date of grant.

The fair value of each stock option granted is estimated using a Black-Scholes option-pricing model, which requires extensive use of accounting judgment and financial estimation, including estimates of the expected term stock option holders will retain their vested stock options before exercising them and the estimated volatility of our Class A common stock price over the expected term.

A summary of stock option activity follows:


	Stock Options (1)	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (years)	Aggregate Intrinsic Value
Outstanding, December 31, 2018	669	$	6.37
Granted	—	$	—
Exercised	(571)	$	5.88
Forfeited	—	$	—
Outstanding, September 30, 2019	98	$	9.20	6.1	$	3,311
Exercisable, September 30, 2019	98	$	9.20	6.1	$	3,311

Stock-based compensation expense for stock options was $0 and $0 during the three and nine months ended September 30, 2019, respectively, as compared to $127 and $377 during the three and nine months ended September 30, 2018, respectively.

During the three and nine months ended September 30, 2019, the aggregate intrinsic value of stock options exercised was $7,741 and $19,475, respectively.

Other Stock Awards

Restricted stock awards, restricted stock units and performance stock units, with the exception of market-based performance stock units, are granted at a price equal to the fair value of our Class A common stock at the date of grant. The fair value of each market-based performance stock unit is estimated using a Monte Carlo pricing model, which requires extensive use of accounting judgment and financial estimation, including the estimated share price appreciation plus the value of dividends of our Class A common stock as compared to the Russell 2000 Index over the requisite service period.

Generally, restricted stock awards granted to non-employee directors vest incrementally over a three year period beginning on the first anniversary of the date of grant. Restricted stock units granted to non-employee directors typically vest in full on the first anniversary of the grant date. Restricted stock units granted to employees vest incrementally over an identified service period beginning on the grant date based on continued employment. Performance stock units granted to employees, including market-based performance stock units, vest at a future date following the grant date and are based on the attainment of performance targets and market achievements, as applicable.

A summary of restricted stock, restricted stock unit and performance stock unit activity follows:


	Restricted Stock, Restricted Stock Units, and Performance Stock Units (1)	Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term (years)	Aggregate Intrinsic Value
Outstanding, December 31, 2018	686	$	15.56
Granted	163	$	37.14
Class A Common Stock Vested	(217)	$	12.19
Forfeited	(7)	$	20.48
Outstanding, September 30, 2019	625	$	22.36	1.1	$	12,866
Unvested, September 30, 2019	950	$	21.90	1.0	$	19,998

(1)Market-based performance stock unit grants are included at the 100% attainment level. Attainment of the maximum performance targets and market achievements would result in the issuance of an additional 325 shares of Class A common stock currently included in unvested.

Stock-based compensation expense related to restricted stock, restricted stock units and performance stock units was $1,858 and $5,084 during the three and nine months ended September 30, 2019, respectively, as compared to $2,007 and $5,883 during the three and nine months ended September 30, 2018, respectively.

During the three and nine months ended September 30, 2019, the total fair value of other stock awards vested was $43 and $7,764, respectively.

As of September 30, 2019, total unrecognized stock-based compensation expense related to outstanding restricted stock and restricted stock units was $3,852, which will be recognized over a weighted average period of 1.4 years. As of September 30, 2019, maximum unrecognized stock-based compensation expense related to outstanding performance stock units, assuming the attainment of maximum performance targets, was $6,009 to be recognized over a weighted average period of 0.9 years.

We also recorded $40 and $134 of stock-based compensation expense related to our Amended and Restated 1997 Employee Stock Purchase Plan during the three and nine months ended September 30, 2019, respectively, as compared to $34 and $106 during the three and nine months ended September 30, 2018, respectively.

Accumulated Other Comprehensive Loss

A summary of the changes in the balances of each component of accumulated other comprehensive loss, net of tax follows:



	Interest Rate Swaps
Balance, December 31, 2018	$	(1,308)

Other comprehensive loss before reclassifications	(5,479)
Amounts reclassified from accumulated other comprehensive loss	216
Income tax provision related to items of other comprehensive loss	—
Net current-period other comprehensive loss	(5,263)
Balance, September 30, 2019	$	(6,571)

A summary of reclassifications out of accumulated other comprehensive loss, net of tax follows:


	Three Months Ended September 30,						Nine Months Ended September 30,
	2019		2018		2019		2018
Details About Accumulated Other Comprehensive Loss Components	Amounts Reclassified Out of Accumulated Other Comprehensive Loss									Affected Line Item in the Consolidated Statements of Operations
Interest rate swaps	$	147	$	156	$	216	$	247	Interest expense
	147		156		216		247		Income before income taxes
	—		—		—		—		Provision (benefit) for income taxes
	$	147	$	156	$	216	$	247	Net income