Consolidated Condensed Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock and Paid-In Capital	Retained Earnings	Other Accumulated Comprehensive Income (Loss)	Treasury Stock
Balance (shares) at May. 31, 2020		186,793			83,378
Balance at May. 31, 2020	$ 3,235,202	$ 1,274,210	$ 7,296,509	$ (153,380)	$ (5,182,137)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	300,005		300,005
Comprehensive income (loss), net of tax	37,430			37,430
Stock-based compensation	29,055	$ 29,055
Vesting of stock-based compensation awards (shares)		568
Stock options exercised, net of shares surrendered (in shares)		795
Stock options exercised, net of shares surrendered	72,123	$ 72,123
Repurchase of common stock (shares)					(230)
Repurchase of common stock	(69,011)				$ (69,011)
Balance (shares) at Aug. 31, 2020		188,156			83,608
Balance at Aug. 31, 2020	3,604,804	$ 1,375,388	7,596,514	(115,950)	$ (5,251,148)
Balance (shares) at May. 31, 2021		189,071			85,010
Balance at May. 31, 2021	3,687,847	$ 1,516,202	7,877,015	30,888	$ (5,736,258)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	331,179		331,179
Comprehensive income (loss), net of tax	(61,154)			(61,154)
Dividends	(98,826)		(98,826)
Stock-based compensation	36,496	$ 36,496
Vesting of stock-based compensation awards (shares)		493
Stock options exercised, net of shares surrendered (in shares)		564
Stock options exercised, net of shares surrendered	72,896	$ 72,896
Repurchase of common stock (shares)					(1,788)
Repurchase of common stock	(659,235)				$ (659,235)
Balance (shares) at Aug. 31, 2021		190,128			86,798
Balance at Aug. 31, 2021	$ 3,309,203	$ 1,625,594	$ 8,109,368	$ (30,266)	$ (6,395,493)