Earnings per Share - Summary of Buyback Activity by Program (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	May 31, 2019	May 31, 2018	May 31, 2017
Equity, Class of Treasury Stock [Line Items]
Purchase Price	$ 1,016,300	$ 127,319	$ 20,724
Share Repurchase Programs
Equity, Class of Treasury Stock [Line Items]
Shares	4,803	518	39
Avg. Price per Share (in dollars per share)	$ 198.53	$ 173.51	$ 94.09
Purchase Price	$ 953,445	$ 89,997	$ 3,691
August 4, 2015
Equity, Class of Treasury Stock [Line Items]
Shares	0	0	39
Avg. Price per Share (in dollars per share)	$ 0.00	$ 0.00	$ 94.09
Purchase Price	$ 0	$ 0	$ 3,691
August 2, 2016
Equity, Class of Treasury Stock [Line Items]
Shares	2,130	518	0
Avg. Price per Share (in dollars per share)	$ 192.55	$ 173.51	$ 0.00
Purchase Price	$ 410,003	$ 89,997	$ 0
October 30, 2018
Equity, Class of Treasury Stock [Line Items]
Shares	2,673	0	0
Avg. Price per Share (in dollars per share)	$ 203.30	$ 0.00	$ 0.00
Purchase Price	$ 543,442	$ 0	$ 0