SHARE-BASED AWARDS AND STOCK OPTIONS

9 Months Ended

Sep. 30, 2020

Share-based Payment Arrangement [Abstract]

The following table summarizes share-based compensation expense and the related income tax benefit recognized for our share-based awards and stock options:


	Three Months Ended				Nine Months Ended
	September 30, 2020		September 30, 2019		September 30, 2020		September 30, 2019

	(in thousands)

Share-based compensation expense	$	42,276	$	27,877	$	105,081	$	55,791
Income tax benefit	$	9,123	$	4,396	$	23,338	$	10,633

Share-Based Awards

The following table summarizes the changes in unvested restricted stock and performance awards for the nine months ended September 30, 2020:


	Shares	Weighted-Average Grant-Date Fair Value

	(in thousands)

Unvested at December 31, 2019	1,844	$149.96
Granted	601	185.71
Vested	(652)	119.62
Forfeited	(51)	169.02
Unvested at September 30, 2020	1,742	$173.10

The total fair value of restricted stock and performance awards vested during the nine months ended September 30, 2020 and September 30, 2019 was $77.9 million and $35.3 million, respectively.

For restricted stock and performance awards, we recognized compensation expense of $38.9 million and $20.2 million during the three months ended September 30, 2020 and 2019, respectively, and $94.9 million and $45.0 million during the nine months ended September 30, 2020 and 2019, respectively. As of September 30, 2020, there were $187.7 million of unrecognized compensation expense related to unvested restricted stock and performance awards that we expect to recognize over a weighted-average period of 2.1 years.

Stock Options

The following table summarizes stock option activity for the nine months ended September 30, 2020:


	Options	Weighted-Average Exercise Price	Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value

	(in thousands)		(years)	(in millions)

Outstanding at December 31, 2019	1,755	$74.06	6.5	$190.3
Granted	124	200.42
Forfeited	(2)	113.48
Exercised	(506)	60.18
Outstanding at September 30, 2020	1,371	$90.64	6.4	$122.0

Options vested and exercisable at September 30, 2020	974	$69.50	5.6	$105.3

We recognized compensation expense for stock options of $2.4 million and $7.0 million during the three months ended September 30, 2020 and 2019, respectively, and $6.5 million and $8.6 million for the nine months ended September 30, 2020 and 2019, respectively. The aggregate intrinsic value of stock options exercised during the nine months ended September 30, 2020 and 2019 was $69.8 million and $22.9 million, respectively. As of September 30, 2020, we had $10.5 million of unrecognized compensation expense related to unvested stock options that we expect to recognize over a weighted-average period of 1.8 years.

The weighted-average grant-date fair value of stock options granted during the nine months ended September 30, 2020 and 2019 was $54.85 and $39.60, respectively. Fair value was estimated on the date of grant using the Black-Scholes valuation model with the following weighted-average assumptions:


	Nine Months Ended
	September 30, 2020	September 30, 2019

Risk-free interest rate	1.24%	1.72%
Expected volatility	30%	31%
Dividend yield	0.39%	0.04%
Expected term (years)	5	5

The risk-free interest rate was based on the yield of a zero coupon U.S. Treasury security with a maturity equal to the expected life of the option from the date of the grant. Our assumption on expected volatility was based on our historical volatility. The dividend yield assumption was determined using our average stock price over the preceding year and the annualized amount of our most current quarterly dividend per share. We based our assumptions on the expected term of the options on our analysis of the historical exercise patterns of the options and our assumption on the future exercise pattern of options.