Common Stock and Stock-Based Compensation (Tables)

12 Months Ended

May 31, 2019

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan

The following table summarizes the Company's total stock-based compensation expense recognized in Cost of sales or Operating overhead expense, as applicable:



	YEAR ENDED MAY 31,
(Dollars in millions)	2019		2018		2017
Stock options⁽¹⁾	$	207	$	149	$	145
ESPPs	40		34		36
Restricted stock	78		35		34
TOTAL STOCK-BASED COMPENSATION EXPENSE	$	325	$	218	$	215


(1)	Expense for stock options includes the expense associated with stock appreciation rights. Accelerated stock option expense is recorded for employees meeting certain retirement eligibility requirements. Accelerated stock option expense was $41 million, $18 million and $14 million for the years ended May 31, 2019, 2018 and 2017, respectively.

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The weighted average assumptions used to estimate these fair values were as follows:



	YEAR ENDED MAY 31,
	2019		2018		2017
Dividend yield	1.0	%	1.2	%	1.1	%
Expected volatility	26.6	%	16.4	%	17.4	%
Weighted average expected life (in years)	6.0		6.0		6.0
Risk-free interest rate	2.8	%	2.0	%	1.3	%

Schedule of Share-based Compensation, Stock Options, Activity

The following summarizes the stock option transactions under the plan discussed above:



	SHARES⁽¹⁾		WEIGHTED AVERAGE OPTION PRICE
	(In millions)
Options outstanding as of May 31, 2018	93.2		$	40.73
Exercised	(18.2	)	29.70
Forfeited	(1.8	)	66.66
Granted	18.1		81.79
Options outstanding as of May 31, 2019	91.3		$	50.59


(1)	Includes stock appreciation rights transactions.

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity

The following summarizes the restricted stock and restricted stock unit activity under the plan discussed above:



	SHARES		WEIGHTED AVERAGE GRANT DATE FAIR VALUE
	(In millions)
Nonvested as of May 31, 2018	2.8		$	59.14
Vested	(0.6	)	59.01
Forfeited	(0.3	)	66.24
Granted	2.5		80.95
Nonvested as of May 31, 2019	4.4		$	70.93