Note 4 - Fair Value Measurements - Summary of Change in Estimated Fair VAlue of Level 3 Financial Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Reclass to additional paid-in-capital upon exercise			$ 8,590	$ 0
Warrant [Member] \| January 2022 Warrants [Member]
Balance at January 1, 2022	$ 0	$ 8,772	0
Issuance of warrants	10,000	0
Change in fair value	(1,228)	(182)
Reclass to additional paid-in-capital upon exercise		(8,590)
Balance at March 31, 2022	8,772	0	0	0
Warrant [Member] \| October 2022 Warrants [Member]
Balance at January 1, 2022	0	0	0
Issuance of warrants	0	16,490
Change in fair value	0	10,391
Reclass to additional paid-in-capital upon exercise		0
Balance at March 31, 2022	$ 0	$ 26,881	$ 26,881	$ 0

Amount of increase to additional paid in capital (APIC) resulting from the exercising of warrants.

No definition available.

Name:	arav_AdjustmentsToAdditionalPaidInCapitalWarrantExercised
Namespace Prefix:	arav_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

+ Details

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

- Definition

Amount of issuances of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

+ Details

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

- Definition

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_WarrantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=arav_January2022WarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=arav_October2022WarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: