Stock-Based Compensation Plans (Tables)

3 Months Ended

Mar. 31, 2021

Share-based Payment Arrangement, Noncash Expense [Abstract]

Schedule of components of stock compensation expense

The components of stock-based compensation expense were as follows:

	Three months ended March 31,
	2021		2020
	(in thousands)
2007 Stock Incentive Plan	$	685	$	1,025
2018 Stock Incentive Plan	1,999		1,060
Employee Stock Purchase Plan	78		32
Total Stock Compensation Expense	$	2,762	$	2,117

Summary of restricted stock activity

The following table summarizes restricted stock activity under the 2007 and 2018 Plans during the three months ended March 31, 2021:

	Shares
Balance as of December 31, 2020	581,715
Shares granted	—
Shares forfeited	—
Shares vested	(4,333)
Balance as of March 31, 2021	577,382