STOCK-BASED COMPENSATION (Tables)

3 Months Ended

Mar. 31, 2020

Share-based Payment Arrangement [Abstract]

Components of Stock-Based Compensation Expenses

The following table summarizes the components of stock-based compensation expense recognized in the Company’s condensed consolidated statements of income and comprehensive income for the periods indicated:

	Three Months Ended   March 31,
	2020		2019
Cost of revenues (exclusive of depreciation and amortization)	$	3,984	$	12,781
Selling, general and administrative expenses	7,897		9,075
Total	$	11,881	$	21,856

Stock Options Activity

Stock option activity under the Company’s plans is set forth below:

	Number of Options		Weighted Average Exercise Price		Aggregate Intrinsic Value		Weighted Average Remaining Contractual Term (in years)
Options outstanding at January 1, 2020	3,322,930		$	50.85
Options granted	144,724		$	175.22
Options exercised	(217,475	)	$	32.84
Options forfeited/cancelled	(7,489	)	$	121.05
Options outstanding at March 31, 2020	3,242,690		$	57.45	$	415,750	4.8
Options vested and exercisable at March 31, 2020	2,856,545		$	45.67	$	399,900	4.3
Options expected to vest at March 31, 2020	352,278		$	143.52	$	14,845	8.8

Service-based Awards Activity

The table below summarizes activity related to the Company’s equity-classified and liability-classified service-based awards for the three months ended March 31, 2020:

	Equity-Classified  Restricted Stock			Equity-Classified Equity-Settled Restricted Stock Units				Liability-Classified Cash-Settled Restricted Stock Units
	Number of Shares	Weighted Average Grant Date Fair Value Per Share		Number of Shares		Weighted Average Grant Date Fair Value Per Share		Number of Shares		Weighted Average Grant Date Fair Value Per Share
Unvested service-based awards outstanding at January 1, 2020	9,791	$	162.96	758,785		$	122.48	242,288		$	105.40
Awards granted	—	$	—	235,231		$	178.79	56,061		$	181.59
Awards vested	—	$	—	(273,904	)	$	104.26	(111,966	)	$	90.08
Awards forfeited/cancelled	—	$	—	(11,838	)	$	128.62	(1,365	)	$	111.01
Unvested service-based awards outstanding at March 31, 2020	9,791	$	162.96	708,274		$	148.13	185,018		$	137.72

Performance-based Awards Activity

The table below summarizes activity related to the Company’s equity-classified performance-based awards for the three months ended March 31, 2020:

	Equity-Classified Equity-Settled Restricted Stock			Equity-Classified Equity-Settled Restricted Stock Units
	Number of Shares	Weighted Average Grant Date Fair Value Per Share		Number of Shares	Weighted Average Grant Date Fair Value Per Share
Unvested performance-based awards outstanding at January 1, 2020	9,393	$	165.87	—	$	—
Awards granted	—	$	—	24,836	$	177.81
Unvested performance-based awards outstanding at March 31, 2020	9,393	$	165.87	24,836	$	177.81