XML 53 R41.htm IDEA: XBRL DOCUMENT v3.20.4
Stock-Based Compensation - Weighted Average Assumptions Used to Estimate Fair Values (Detail) - USD ($)
$ / shares in Units, $ in Millions
6 Months Ended
Nov. 30, 2020
Nov. 30, 2019
Stock options    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Weighted average fair value per share of the options granted (in dollars per share) $ 26.75 $ 18.46
Dividend yield 0.90% 1.00%
Expected volatility 27.30% 23.00%
Weighted average expected life 6 years 6 years
Risk-free interest rate 0.40% 1.50%
Stock Incentive Plan | Stock options    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Unrecognized compensation costs from stock options $ 589  
Unrecognized compensation costs from stock options, net of estimated forfeitures, to be recognized as operating overhead expense over a weighted average period (in years) 2 years 8 months 12 days  
Class B Common Stock | Stock Incentive Plan    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Minimum term of market traded options for estimates of expected volatility 1 year