XML 38 R28.htm IDEA: XBRL DOCUMENT v3.21.2

Cash and Marketable Securities - Components of marketable securities (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Aug. 31, 2021	May 31, 2021
Marketable Securities [Line Items]
Amortized Cost	$ 329,660	$ 305,279
Unrealized gains	60	239
Unrealized Losses	(123)	(33)
Fair Value	329,597	305,485
Commercial Paper And Corporate Bonds [Member]
Marketable Securities [Line Items]
Amortized Cost	327,157	299,524
Unrealized gains	53	209
Unrealized Losses	(123)	(33)
Fair Value	327,087	299,700
Certificates of Deposit [Member]
Marketable Securities [Line Items]
Amortized Cost	2,503	5,755
Unrealized gains	7	30
Unrealized Losses
Fair Value	$ 2,510	$ 5,785

X

- Definition

Amount of unrealized gain on investment in debt security measured at fair value with change in fair value recognized in net income (trading).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27357-111563

+ Details

Name:	us-gaap_DebtSecuritiesTradingUnrealizedGain
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of unrealized loss on investment in debt security measured at fair value with change in fair value recognized in net income (trading).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27357-111563

+ Details

Name:	us-gaap_DebtSecuritiesTradingUnrealizedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_MarketableSecuritiesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562

+ Details

Name:	us-gaap_TradingSecuritiesDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amortized cost of investments in debt securities classified as trading.

+ References

No definition available.

+ Details

Name:	us-gaap_TradingSecuritiesDebtAmortizedCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_CashAndCashEquivalentsAxis=neog_CommercialPaperandCorporateBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_CashAndCashEquivalentsAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: