Stock-Based Compensation Expense (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Share-based Payment Arrangement, Shares/Units Available For Grant

Shares available for grant as of December 31, 2019 and the activity during the year ended December 31, 2019 are as follows:



	Total
Balance as of December 31, 2018	1,041,068
Restricted stock units granted ⁽¹⁾	(248,155	)
Options granted	—
Options forfeited	23,826
Options expired	—
Restricted stock units forfeited ⁽¹⁾	12,352
Balance as of December 31, 2019	829,091

(1) Includes time-based and performance-based RSUs

Share-based Payment Arrangement, Option, Activity

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



	Options Outstanding
	Outstanding Stock Options		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value ⁽²⁾
Outstanding as of December 31, 2018	581,124		$	25.47	4.4	$	—
Granted	—		—			—
Exercised	—		—			—
Forfeited	(23,826	)	$	25.70		—
Expired	—		—			—
Outstanding as of December 31, 2019	557,298		$	25.46	3.4	$	—
Exercisable as of December 31, 2019	180,424		$	24.97
Vested and expected to vest as of December 31, 2019	557,298		$	25.46	3.4	$	—

⁽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.

The following table summarizes changes in outstanding options and the related weighted-average exercise price per share for the period from June 4, 2018 to December 31, 2018:



	Options Outstanding
	Outstanding Stock Options	Weighted-Average Exercise Price
Outstanding as of June 4, 2018	—	$	—
Granted	581,124	25.47
Exercised	—	—
Forfeited	—	—
Expired	—	—
Outstanding as of December 31, 2018	581,124	$	25.47
Exercisable as of December 31, 2018	14,180	$	18.75
Vested and expected to vest as of December 31, 2018	581,124	$	25.47

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

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



	Period from June 4, 2018 through December 31, 2018
Expected term (in years)	5.0
Risk-free interest rate	2.44	%
Expected volatility	75	%
Expected dividend yield	0	%

Schedule of Nonvested Restricted Stock Units Activity

The following table summarizes the activities for our RSUs for the year ended December 31, 2019 and the period June 4, 2018 through December 31, 2018 and the related weighted-average grant date fair value:



	Number of RSUs		Weighted-Average Grant Date Fair Value
Nonvested as of June 4, 2018	—		$	—
Granted	600,031		15.00
Vested	(122,063	)	15.00
Forfeited	—		—
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
Expected to vest as of December 31, 2019	474,718		$	14.46

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 for the year ended December 31, 2019, and period from June 4, 2018 through December 31, 2018 was as follows (dollars in thousands):



	Year Ended December 31, 2019		Period from June 4, 2018 through December 31, 2018
Stock option grants	$	1,326	$	853
Restricted stock unit grants	3,975		2,551
Total expense	$	5,301	$	3,404