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, 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	584,862
Comprehensive income (loss), net of tax	55,973
Balance (shares) at Nov. 30, 2020		188,601			83,615
Balance at Nov. 30, 2020	3,597,960	$ 1,439,342	7,509,544	(97,407)	$ (5,253,519)
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)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	284,857		284,857
Comprehensive income (loss), net of tax	18,543			18,543
Dividends	(371,827)		(371,827)
Stock-based compensation	28,547	$ 28,547
Vesting of stock-based compensation awards (shares)		21
Stock options exercised, net of shares surrendered (in shares)		424
Stock options exercised, net of shares surrendered	$ 35,407	$ 35,407
Repurchase of common stock (shares)	0				(7)
Repurchase of common stock	$ (2,371)				$ (2,371)
Balance (shares) at Nov. 30, 2020		188,601			83,615
Balance at Nov. 30, 2020	3,597,960	$ 1,439,342	7,509,544	(97,407)	$ (5,253,519)
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)
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	625,848
Comprehensive income (loss), net of tax	(58,146)
Balance (shares) at Nov. 30, 2021		190,476			86,811
Balance at Nov. 30, 2021	3,563,127	$ 1,686,293	8,305,076	(27,258)	$ (6,400,984)
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)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	294,669		294,669
Comprehensive income (loss), net of tax	3,008			3,008
Dividends	(98,961)		(98,961)
Stock-based compensation	24,397	$ 24,397
Vesting of stock-based compensation awards (shares)		31
Stock options exercised, net of shares surrendered (in shares)		317
Stock options exercised, net of shares surrendered	$ 36,302	$ 36,302
Repurchase of common stock (shares)	0				(13)
Repurchase of common stock	$ (5,491)				$ (5,491)
Balance (shares) at Nov. 30, 2021		190,476			86,811
Balance at Nov. 30, 2021	$ 3,563,127	$ 1,686,293	$ 8,305,076	$ (27,258)	$ (6,400,984)