Stock-Based Compensation

3 Months Ended

Feb. 29, 2020

Share-based Payment Arrangement [Abstract]

Stock-Based Compensation

Stock-Based Compensation

Stock Options. We estimate the grant-date fair value of stock options using the Black-Scholes option-pricing model. The following table summarizes stock option transactions for the three months ended February 29, 2020:

	Options		Weighted Average Exercise Price
Options outstanding at beginning of period	4,163,481		$	13.00
Granted	—		—
Exercised	(698,372	)	11.78
Cancelled	(6,000	)	45.16
Options outstanding at end of period	3,459,109		$	13.20
Options exercisable at end of period	3,459,109		$	13.20

We have not granted any new stock option awards since 2016. As of February 29, 2020, stock options outstanding and stock options exercisable each had a weighted average remaining contractual life of 4.4 years. At February 29, 2020, there was no unrecognized compensation expense related to stock option awards as all of these awards were fully vested. For the three-month period ended February 29, 2020, there was no stock-based compensation expense associated with stock options. For the three months ended February 28, 2019, stock-based compensation expense associated with stock options was nominal. Stock options outstanding and stock options exercisable each had an aggregate intrinsic value of $67.1 million at February 29, 2020. (The intrinsic value of a stock option is the amount by which the market value of a share of the underlying common stock exceeds the exercise price of the stock option.)

Other Stock-Based Awards. From time to time, we grant restricted stock and PSUs to various employees as a compensation benefit. We recognized total compensation expense of $5.0 million and $4.1 million for the three months ended February 29, 2020 and February 28, 2019, respectively, related to restricted stock and PSUs.