Stock-Based Compensation Expense (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Share-based Payment Arrangement, Option, Activity

The following table summarizes changes in outstanding stock options during the twelve months ended December 31, 2020 and 2019, as well as stock options that are vested and expected to vest and stock options exercisable as of December 31, 2020 and 2019: 

	Options Outstanding
	Outstanding Stock Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands) (2)
Outstanding as of December 31, 2018	581,124	$	25.47	4.4	$	—
Granted	—	—			—
Exercised	—	—			—
Forfeited and canceled	(23,826)	25.70			—
Outstanding as of December 31, 2019	557,298	$	25.46	3.4	$	—
Exercisable as of December 31, 2019	180,424	$	24.97
Outstanding as of December 31, 2019	557,298	$	25.46	3.4	$	—
Granted	347,800	$	12.89		—
Exercised	—	—			—
Forfeited and canceled	(133,984)	$	24.52		—
Outstanding as of December 31, 2020	771,114	$	20.00	3.4	$	253
Exercisable as of December 31, 2020	271,103	$	25.22
(2) Amounts represent the difference between the exercise price and the fair value of common stock at each year end for all the "in-the-money" options outstanding based on the fair value per share of common stock as of each respective fiscal year end.

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The per-share fair value of each stock option with service conditions only granted in 2020 was determined on the grant date using the Black-Scholes option pricing model with the following assumptions:

	Grant date
	2/13/2020		3/23/2020
Expected term (in years)	3.75		3.75
Risk-free interest rate	1.5	%	1.3	%
Expected volatility	46.9	%	68.2	%
Expected dividend yield	0	%	0	%

Schedule of Nonvested Restricted Stock Units Activity

The following table summarizes the activities for our RSUs for the years ended December 31, 2020 and 2019 and the related weighted-average grant date fair value:

	Number of RSUs	Weighted-Average Grant Date Fair Value
Nonvested as of December 31, 2018	477,968	$	15.00
Granted	248,155	14.16
Vested	(239,053)	15.22
Forfeited	(12,352)	14.84
Nonvested as of December 31, 2019	474,718	$	14.46
Granted	341,327	10.20
Vested	(212,193)	10.67
Forfeited	(230,721)	14.24
Nonvested as of December 31, 2020	373,131	$	12.65

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award

The total stock-based compensation expense included in "Corporate expenses" in the accompanying Consolidated Statements of Operations was as follows (dollars in thousands):

    

	Year Ended December 31, 2020		Year Ended December 31, 2019
Stock option grants	$	1,044	$	1,326
Restricted stock unit grants	2,293		3,975
Total expense	$	3,337	$	5,301