Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Feb. 28, 2017	Feb. 28, 2017	May 31, 2017	May 31, 2009	Feb. 28, 2018
Goodwill And Intangible Assets [Line Items]
Impairment charges related to carrying value of goodwill and other intangible assets	$ 4,900	$ 193,198
Goodwill impairment loss			$ 140,500
Impairment losses for other intangible assets			52,600
Accumulated impairment losses	155,400	155,400			$ 156,300
Other intangible asset accumulated impairment losses, gross	$ 53,200	$ 53,200			$ 53,600
Industrial Segment
Goodwill And Intangible Assets [Line Items]
Accumulated impairment losses				$ 14,900
Intangible asset impairment loss				$ 600
Formulae
Goodwill And Intangible Assets [Line Items]
Impairment losses for other intangible assets			15,300
Customer-related Intangibles
Goodwill And Intangible Assets [Line Items]
Impairment losses for other intangible assets			30,100
Other Intangibles
Goodwill And Intangible Assets [Line Items]
Impairment losses for other intangible assets			200
Indefinite-lived Trademarks
Goodwill And Intangible Assets [Line Items]
Impairment losses for other intangible assets			$ 7,000