STOCK-BASED COMPENSATION (Tables)

9 Months Ended

Sep. 30, 2020

STOCK-BASED COMPENSATION

Schedule of weighted-average assumptions used to estimate the fair value of options granted

	Three-Months Ended September 30,			Nine-Months Ended September 30,
	2020*	2019		2020		2019
Dividend yield	—	0.0	%	0.0	%	0.0	%
Expected volatility	—	30.2	%	30.5	%	30.2	%
Risk-free interest rate	—	1.4	%	0.7	%	2.4	%
Expected term	—	5.8	years	5.8	years	6.0	years

*No options were granted during the three-months ended September 30, 2020.

Summary of activities with respect to its stock option plans

				Weighted-
		Weighted-		Average
		Average		Remaining
	Number of	Exercise		Contractual	Aggregate
	Shares (in	Price Per		Term (In	Intrinsic
Options	thousands)	Share		years)	Value
Outstanding at January 1, 2020	14,941	$	42.88	6.3	$	308,884
Granted 01/01/20 - 03/31/20	1,027	$	62.45
Granted 04/01/20 - 06/30/20	—	$	—
Granted 07/01/20 - 09/30/20	—	$	—
Exercised	(1,711)	$	38.30
Cancelled or forfeited	(53)	$	52.91
Outstanding at September 30, 2020	14,204	$	44.81	6.0	$	502,732
Vested and expected to vest in the future at September 30, 2020	13,594	$	44.23	5.9	$	488,969
Exercisable at September 30, 2020	8,174	$	36.97	4.7	$	353,333

No options were granted during the three-months ended September 30, 2020. The weighted-average grant-date fair value of options granted during the three-months ended September 30, 2019 was $18.32 per share. The weighted-average grant-date fair value of options granted during the nine-months ended September 30, 2020 and 2019 was $18.78 per share and $20.24 per share, respectively.

Summary of activities with respect to non-vested restricted stock units

		Weighted
	Number of	Average
	Shares (in	Grant-Date
	thousands)	Fair Value
Non-vested at January 1, 2020	825	$	57.62
Granted 01/01/20 - 03/31/201	392	$	62.39
Granted 04/01/20 - 06/30/20	17	$	71.72
Granted 07/01/20 - 09/30/20	1	$	71.76
Vested	(287)	$	55.65
Forfeited/cancelled	(2)	$	59.67
Non-vested at September 30, 2020	946	$	60.46