Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Schedule of stock-based compensation

	Years Ended December 31,
	2019		2018		2017
Stock-based compensation expense	$	7,327	$	9,703	$	12,549

Disclosure of compensation related costs

Changes in the unvested RSU’s during the years ended December 31, 2019, 2018 and 2017 were as follows:

	2019			2018			2017
		Weighted-			Weighted-			Weighted-
		Average			Average			Average
		Grant			Grant			Grant
	Shares	Value		Shares	Value		Shares	Value
RSUs outstanding at beginning of period	352	$	58.17	386	$	51.06	354	$	29.60
RSUs granted	380		52.24	245		64.48	252		63.63
RSUs vested	(155)		50.95	(207)		54.94	(211)		30.62
RSUs forfeited	(43)		51.82	(72)		50.79	(9)		33.91
RSUs outstanding at end of period	534	$	56.56	352	$	58.17	386	$	51.06

Schedule of shares authorized under stock option plans, by exercise price range

The following table summarizes information about the stock options outstanding at December 31, 2019:

	Options Outstanding				Options Exercisable
		Weighted-Average	Weighted-			Weighted-
	Number	Remaining	Average		Number	Average
Range of Exercise Prices	Outstanding	Contractual Life	Exercise Price		Exercisable	Exercise Price
9.51 - 13.85	23	1.42 years	$	12.00	23	$	12.00
14.21 - 16.25	20	0.72 years		15.06	20		15.06
18.77 - 18.77	43	4.75 years		18.77	43		18.77
26.32 - 26.32	99	5.10 years		26.32	99		26.32
9.51 - 26.32	185	4.09 years	$	21.56	185	$	21.56

Employee Stock [Member]

Schedule of valuation assumptions

The fair value of each purchase right granted under the ESPP was estimated on the date of grant using the Black-Scholes-Merton option pricing model with the following assumptions:

	2019		2018		2017
Risk-free interest rates	1.62% - 2.31	%	2.10% - 2.56	%	1.07% - 1.45	%
Expected dividend yield rates	—	%	—	%	—	%
Expected term	0.5 years		0.5 years		0.5 years
Expected volatility	41.3	%	38.0	%	33.3	%

Time Based [Member]

Schedule of stock options roll forward

Changes in our outstanding stock options during the years ended December 31, 2019, 2018 and 2017 were as follows:

	2019			2018			2017
		Weighted-			Weighted-			Weighted-
		Average			Average			Average
		Exercise			Exercise			Exercise
	Shares	Price		Shares	Price		Shares	Price
Options outstanding at beginning of period	230	$	20.73	317	$	18.97	474	$	17.47
Options exercised	(42)		17.73	(83)		14.41	(152)		14.32
Options forfeited	—		—	—		—	(2)		26.32
Options expired	(3)		9.91	(4)		11.97	(3)		11.09
Options outstanding at end of period	185	$	21.56	230	$	20.73	317	$	18.97
Options vested during the year	—			2			9

Schedule of restricted stock and restricted stock units activity

	Options Outstanding				Options Exercisable
		Weighted-Average	Weighted-			Weighted-
	Number	Remaining	Average		Number	Average
Range of Exercise Prices	Outstanding	Contractual Life	Exercise Price		Exercisable	Exercise Price
9.51 - 13.85	23	1.42 years	$	12.00	23	$	12.00
14.21 - 16.25	20	0.72 years		15.06	20		15.06
18.77 - 18.77	43	4.75 years		18.77	43		18.77
26.32 - 26.32	99	5.10 years		26.32	99		26.32
9.51 - 26.32	185	4.09 years	$	21.56	185	$	21.56