Number of shares available for sale under employee stock purchase plan.

No definition available.

Name:	acet_NumberOfSharesAvailableForSaleUnderEmployeeStockPurchasePlan
Namespace Prefix:	acet_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Probability of achieving milestone.

+ References

No definition available.

+ Details

Name:	acet_ProbabilityOfAchievingMilestone
Namespace Prefix:	acet_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award number of shares available for grant, shares granted.

+ References

No definition available.

+ Details

Name:	acet_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantSharesGranted
Namespace Prefix:	acet_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

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

- Definition

Number of additional shares authorized for issuance under share-based payment arrangement.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares authorized for issuance under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average grant-date fair value of options vested.

+ References

No definition available.

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_PlanNameAxis=acet_TwoThousandSeventeenAndTwoThousandEighteenStockIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=acet_TwoThousandFourteenStockIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=acet_TwoThousandFifteenStockIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=acet_TwoThousandEighteenEmployeeStockPurchasePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=acet_InducementGrantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=acet_PerformanceRestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stock-Based Compensation - Additional Information (Details) - $ / shares				1 Months Ended	3 Months Ended	9 Months Ended
	May 31, 2021	Jan. 01, 2021	Jan. 01, 2020	Aug. 31, 2021	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares Available for Grant, Options granted						(2,171,632)
Number of shares of common stock available for grant					2,693,497	2,693,497	1,739,621
Number of shares reserved for issuance					362,503	362,503
Weighted-Average Exercise Price, Options exercised						$ 2.98
2017 and 2018 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock available for grant					2,349,535	2,349,535
Number of shares reserved for issuance					2,686,287	2,686,287
Weighted-Average Exercise Price, Options exercised						$ 15.41
2014 Stock Incentive Plan Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance					22,989	22,989
Weighted-Average Exercise Price, Options exercised						$ 1.61
2015 Stock Incentive Plan Member
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock available for grant					343,961	343,961
Number of shares reserved for issuance					1,421,746	1,421,746
Weighted-Average Exercise Price, Options exercised						$ 8.96
2018 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares reserved for issuance		209,135	131,432			524,775
Number of shares available for sale under employee stock purchase plan					0	0
Inducement Grant
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-Average Exercise Price, Options exercised						$ 14.33
Performance Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock available for grant	6,410
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Probability of Achieving Milestone						100.00%
Grant fair value	$ 15.60
Number of shares of common stock available for grant				210,750
Weighted-Average Exercise Price, Options exercised				$ 7.12
Performance Stock Units (PSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares Available for Grant, Options granted	(6,410)