Commitments and Contingencies (Details Textual) - USD ($) $ in Millions		1 Months Ended		3 Months Ended			9 Months Ended		12 Months Ended	50 Months Ended
	Aug. 01, 2019	Sep. 30, 2021	Oct. 31, 2017	Sep. 30, 2025	Mar. 31, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024	Sep. 25, 2023	Feb. 29, 2020
Commitment And Contingencies [Line Items]
Operating lease costs				$ 1.3		$ 1.3	$ 3.8	$ 4.1
October 2017 Lease Amendment [Member]
Commitment And Contingencies [Line Items]
Operating lease extended additional term			84 months
Lessee, operating lease, term of contract			4 months
Tenant improvement allowance			$ 0.1
Security deposit			$ 0.1
February 2020 Lease Agreement [Member]
Commitment And Contingencies [Line Items]
Operating lease extended additional term											13 months
Lessee, operating leases, option to extend							the lease for one twelve-month period. In February 2021, the Company opted to extend the lease through March 2025 to coincide with the lease term of the Company’s headquarters.
Impairment loss					$ 1.3
September 2021 Lease Agreement [Member]
Commitment And Contingencies [Line Items]
Operating lease extended additional term		10 years 8 months
Lessee, operating leases, option to extend							the Company has the right to extend the term of the lease for an additional five-year period.
Security deposit		$ 2.0
Underlying Agreement [Member] \| Cystic Fibrosis Foundation [Member]
Commitment And Contingencies [Line Items]
Contra expense remaining amount included in accrued expenses							$ 6.6		$ 7.4
Minimum amount agreed to incur under research plan										$ 15.0
Total expense recognized period						$ 0.3
Contra expense included in research and development expense				$ 0.2			$ 0.9	$ 0.5
Underlying Agreement [Member] \| LUNAR-CF [Member] \| Cystic Fibrosis Foundation [Member]
Commitment And Contingencies [Line Items]
Payments for advance	$ 15.6									$ 24.6
Maximum [Member] \| September 2021 Lease Agreement [Member]
Commitment And Contingencies [Line Items]
Monthly base rent		0.4
Minimum [Member] \| September 2021 Lease Agreement [Member]
Commitment And Contingencies [Line Items]
Monthly base rent		$ 0.3

Arcturus Therapeutics Holdings Inc. 10-Q