Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended
	Aug. 31, 2019	Jun. 01, 2019
Significant Accounting Policies [Line Items]
Products and services, payment terms	30 to 60 days
Operating lease right of use asset	$ 1,726,000	$ 2,000,000.0
Operating lease liability	1,737,000	$ 2,000,000.0
Operating lease payments	247,000
Right of use assets in exchange of lease liability	$ 0
Minimum
Significant Accounting Policies [Line Items]
Marketable securities, maturity period	91 days
Finite lived intangible assets, useful life	5 years
Maximum
Significant Accounting Policies [Line Items]
Marketable securities, maturity period	2 years
Finite lived intangible assets, useful life	25 years