Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

Summary Components of Stock-Based Compensation Expense

The following table summarizes the components of stock-based compensation expense in the Consolidated Statements of Operations for the years ended December 31, 2018, 2017 and 2016:

	Years Ended December 31,
	2018		2017		2016
Cost of services	$	666	$	525	$	559
Cost of product sales		162		78		44
Selling, general and administrative		6,065		4,706		4,082
Product development		1,017		364		338
Total	$	7,910	$	5,673	$	5,023

Time-Based Stock Appreciation Rights [Member]

Summary of Stock Appreciation Rights

A summary of the Company’s time-based Stock Appreciation Rights (“SARs”) for the year ended December 31, 2018 is as follows:

	Number of Shares			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (years)		Aggregate Intrinsic Value
Outstanding at January 1, 2018		2,564,394		$	5.38
Granted		—			—
Exercised		(345,300	)		4.93
Forfeited or expired		(20,000	)		8.58
Outstanding at December 31, 2018		2,199,094		$	5.36		3.69	$	5,514
Exercisable at December 31, 2018		2,139,094		$	5.41		3.56	$	5,867
Vested and expected to vest at December 31, 2018		2,199,094		$	5.36		3.69	$	5,514

Performance-Based Stock Appreciation Rights [Member]

Summary of Stock Appreciation Rights

A summary of the Company’s performance-based SARs for the year ended December 31, 2018 is as follows:

	Number of Shares			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term  (years)		Aggregate Intrinsic Value
Outstanding at January 1, 2018		504,473		$	5.80
Granted		—			—
Exercised		(186,187	)		2.74
Forfeited or expired		(84,790	)		11.00
Outstanding at December 31, 2018		233,496		$	6.02		4.62	$	1,418
Exercisable at December 31, 2018		233,496		$	6.02		4.62	$	1,418
Vested and expected to vest at December 31, 2018		233,496		$	6.02		4.62	$	1,418

Fair Value of Stock Appreciation Rights Estimated

The fair value of each time-based and performance-based SAR award is estimated on the date of grant using the Black-Scholes option pricing model with the assumptions described below. For the period indicated, the expected volatility was based on the Company’s historical volatility over the expected terms of the SAR awards. Estimated forfeitures were based on voluntary and involuntary termination behavior, as well as an analysis of actual forfeitures. The risk-free interest rate was based on the U.S. Treasury yield curve at the time of the grant over the expected term of the SAR grants. The Company did not grant time-based or performance-based SARs during the years ended December 31, 2018 and 2016.

	Year Ended December 31,
	2018	2017		2016
Risk-free interest rate	None	2.10%		None
Expected life (years)	None		6.0	None
Estimated volatility factor	None	59.85%		None
Expected dividends	None	None		None

Time-Based Restricted Stock Units [Member]

Summary of Restricted Stock Units

A summary of the Company’s time-based Restricted Stock Units (“RSUs”) for the year ended December 31, 2018 is as follows:

	Shares			Weighted-Average Grant Date Fair Value
Balance at January 1, 2018		818,480		$	9.95
Granted		606,249			9.44
Vested		(432,189	)		9.32
Forfeited or expired		(72,516	)		10.46
Balance at December 31, 2018		920,024		$	9.60

Performance-Based Restricted Stock Units [Member]

Summary of Restricted Stock Units

A summary of the Company’s performance-based RSUs for the year ended December 31, 2018 is as follows:

	Shares			Weighted-Average Grant Date Fair Value
Balance at January 1, 2018		444,734		$	9.48
Granted		387,748			9.15
Vested		(168,068	)		9.16
Forfeited or expired		(50,809	)		9.41
Balance at December 31, 2018		613,605		$	9.44

Market Performance Units [Member]

Fair Value of Stock Appreciation Rights Estimated

As the MPUs contain both performance and service conditions, they have been treated as a series of three separate awards, or tranches, for purposes of recognizing stock-based compensation expense. The Company recognizes stock-based compensation expense on a tranche-by-tranche basis over the requisite service period for that specific tranche. The Company estimated the fair value of the MPUs using a Monte Carlo simulation model based on the following assumptions:

	Years Ended December 31,
	2018	2017	2016
Risk-free interest rate	2.46% to 2.63%	1.76% to 1.98%	0.85% to 1.47%
Estimated volatility factor	29.0%to32.0%	27.0%to31.0%	33.0%to36.0%
Expected dividends	None	None	None