Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

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

The following table sets forth the weighted-average stock option fair values and assumptions:

	Years Ended December 31,
	2020			2019			2018
Weighted-average fair value	$	6.97		$	10.24		$	15.43
Dividend yield	—			—			—
Volatility	52.06		%	39.37		%	47.39		%
Risk-free interest rate	0.30		%	1.68		%	2.47		%
Expected life (in years)	4.82			4.47			4.03

Schedule of Stock Option Activity

The following tables reflect changes in the Company's outstanding stock-based compensation awards for the years ended December 31, 2020 and 2019:

	2020
	Number of Stock Option Awards	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)	Aggregate Intrinsic Value
Outstanding stock option awards at January 1	5,875,829	$	9.29	8.15	$	42,433,615
Granted	872,003	11.90		9.87	1,393,499
Exercises (net cash settled)	(130,017)	3.68		5.74	896,335
Exercises (issuance of shares)	(2,143,317)	3.69		5.77	15,510,765
Forfeitures/expirations	(196,338)	13.22		8.64	(146,415)
Outstanding stock option awards as of December 31, 2020	4,278,160	$	11.20	8.36	$	9,855,005
Options exercisable as of December 31	992,061	$	4.28	5.81	$	9,151,100

	2019
	Number of Stock Option Awards	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)	Aggregate Intrinsic Value
Outstanding stock option awards at January 1	6,069,907	$	3.87	6.79	$	90,463,239
Granted	2,555,109	16.20		9.88	—
Exercises (net cash settled, see Tender Offer below)	(2,326,019)	3.69		6.75	33,901,447
Exercises (issuance of shares)	(111,660)	3.92		6.78	1,420,239
Forfeitures/expirations	(311,508)	4.18		6.81	3,745,889
Outstanding stock option awards at December 31, 2019	5,875,829	$	9.29	8.15	$	42,433,615
Options exercisable as of December 31	2,341,193	$	3.80	6.78	$	29,029,972

Schedule of Stock-Based Compensation Expense

The following table sets forth stock-based compensation (benefit) expense, including the effects of gains and losses from change in fair value recognized by the Company in the following line items in the Company's consolidated statements of operations during the periods presented (in thousands):

	Years Ended December 31,
	2020		2019		2018
Cost of services	$	(72)	$	381	$	4,156
Sales and marketing	266		1,649		4,276
General and administrative	(3,089)		12,089		31,172
Stock-based compensation (benefit) expense	$	(2,895)	$	14,119	$	39,604