Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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Balance Type:	debit
Period Type:	duration

Stock Repurchase Program - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2018	Nov. 30, 2017	Nov. 30, 2018	Nov. 30, 2017	May 31, 2021
Stock Repurchase Programs [Line Items]
Authorization of stock repurchase program			Jan. 08, 2008
Shares repurchased	1,144,952	0	1,248,398	0
Shares repurchased, value	$ 74,998		$ 81,992
Repurchase of common stock price per shares	$ 65.50		$ 65.68
Scenario Forecast
Stock Repurchase Programs [Line Items]
Capital to be returned to stockholders through dividends and share repurchases					$ 1,500,000