Aggregate amount of ordinary shares sold.

No definition available.

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- Definition

Compensation percentage of cash equivalent to gross proceeds for ordinary shares sold.

+ References

No definition available.

+ Details

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- Definition

Debt instrument amortization period.

+ References

No definition available.

+ Details

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- Definition

Debt instrument amortization period for extended interest only period.

+ References

No definition available.

+ Details

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- Definition

Debt instrument Interest-only repayment period.

+ References

No definition available.

+ Details

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- Definition

Debt instrument interest only repayment period extended.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Prepayment fee percentage.

+ References

No definition available.

+ Details

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Namespace Prefix:	arct_
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Balance Type:	na
Period Type:	duration

- Definition

Prepayment fee percentage after accepting new drug applications prior to maturity.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Warrant fee payable.

+ References

No definition available.

+ Details

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Namespace Prefix:	arct_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

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- Definition

Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-SubTopic 470
-Section 50
-Paragraph 3
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-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

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- Definition

Cash received from principal payments made on loans related to operating activities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3536-108585

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Balance Type:	debit
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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- Definition

Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533

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Subsequent Events (Details Textual) - USD ($)		1 Months Ended	9 Months Ended
Subsequent Events (Details Textual) - USD ($)	Oct. 12, 2018	Oct. 31, 2018	Sep. 30, 2018
Loan and Security Agreement [Member] \| Western Alliance Bank [Member] \| Term Loan [Member]
Subsequent Event [Line Items]
Loan interest payment terms			The loan has an interest-only period of 18 months, which could be extended by an additional 6 months if certain conditions are met, followed by an amortization period of 30 months, or 24 months if the interest-only period is extended. Upon maturity or prepayment, the Company will be required to pay a 3% fee, or a 2% fee if the U.S. Food and Drug Administration accepts certain Investigational New Drug applications prior to maturity.
Loan and Security Agreement [Member] \| Western Alliance Bank [Member] \| Term Loan [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Gross proceeds from term loan agreement	$ 10,000,000
Term loan maturity date	Oct. 01, 2022
Interest of the prime rate plus	1.25%
Loan interest-only payment period	18 months
Loan interest-only payment period	6 months
Debt Instrument, amortization period	30 months
Debt Instrument, amortization period	24 months
Prepayment fee percentage	3.00%
Prepayment fee percentage	2.00%
Loan orgination fee paid	$ 50,000
Warrant fee payable	$ 350,000
Leerink Partners LLC [Member] \| Sales Agreement [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Compensation percentage of cash equivalent to gross proceeds for ordinary shares sold		3.00%
Leerink Partners LLC [Member] \| Maximum [Member] \| Sales Agreement [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Aggregate amount of ordinary shares sold		$ 30,000,000