Stock-Based Compensation

6 Months Ended

May 31, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation

Stock-Based Compensation

We measure and recognize compensation expense associated with our grant of equity-based awards in accordance with Accounting Standards Codification Topic No. 718, “Compensation — Stock Compensation” (“ASC 718”). ASC 718 requires that companies measure and recognize compensation expense at an amount equal to the fair value of share-based payments granted under compensation arrangements over the vesting period.

Stock Options. In accordance with ASC 718, we estimate the grant-date fair value of stock options using the Black-Scholes option-pricing model, which takes into account assumptions regarding an expected dividend yield, a risk-free interest rate, an expected volatility factor for the market price of our common stock and an expected term of the stock options. The following table summarizes stock option transactions for the six months ended May 31, 2013:

	Options		Weighted Average Exercise Price
Options outstanding at beginning of period	10,105,546		$	21.27
Granted	—		—
Exercised	(112,586	)	13.47
Cancelled	—		—
Options outstanding at end of period	9,992,960		$	21.36
Options exercisable at end of period	8,431,121		$	23.88

As of May 31, 2013, the weighted average remaining contractual life of stock options outstanding and stock options exercisable was 5.8 years and 5.4 years, respectively. There was $.9 million of total unrecognized compensation expense related to unvested stock option awards as of May 31, 2013. For the three months ended May 31, 2013 and 2012, stock-based compensation expense associated with stock options totaled $.4 million and $1.2 million, respectively. For the six months ended May 31, 2013 and 2012, stock-based compensation expense associated with stock options totaled $.8 million and $2.4 million, respectively. The aggregate intrinsic value of stock options outstanding was $56.6 million at May 31, 2013. The aggregate intrinsic value of stock options exercisable was $34.0 million at May 31, 2013. (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, performance-based restricted stock units (each a “PSU”) and phantom shares to various employees. We recognized total compensation expense of $.7 million for the three months ended May 31, 2013 and $.4 million for the three months ended May 31, 2012 related to restricted stock, PSUs and phantom shares. We recognized total compensation expense of $1.3 million for the six months ended May 31, 2013 and $.8 million for the six months ended May 31, 2012 related to these stock-based awards.