Commitments and Contingencies - Additional Information (Detail)		1 Months Ended				3 Months Ended		9 Months Ended
	Nov. 08, 2021 USD ($)	Jun. 30, 2022 USD ($)	Apr. 30, 2022 USD ($)	Nov. 30, 2021 USD ($)	May 31, 2017 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) Vehicle	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Jul. 01, 2013 USD ($)
Commitments And Contingencies [Line Items]
Accrued expenses and other current liabilities						$ 900,000		$ 900,000		$ 1,100,000
Milestone liabilities						4,524,000		4,524,000		4,838,000
Operating lease costs						408,000	$ 323,000	1,037,000	$ 1,008,000
Financing liability						104,000,000.0		104,000,000.0		100,500,000
Financing liability, long term				$ 94,500,000		94,484,000		94,484,000		93,525,000
Financing liability, short term				9,500,000		9,525,000		$ 9,525,000		$ 6,977,000
Payment of long term purchase commitment, amendment fees									$ 2,000,000.0
Supply Agreement expiration period								Dec. 31, 2027
Supply Agreement renewal period								2 years
Description of right to extension of lease term								The Company will receive a six-month concession at the start of the lease extension period on July 31, 2023. The Company has no further right to extend the lease term beyond the Extension Period.
Equipment | V-Go
Commitments And Contingencies [Line Items]
Embedded lease cost per month		$ 14,370
Master Lease Agreement with Enterprise | Vehicle Leases
Commitments And Contingencies [Line Items]
Number of vehicle leases retired | Vehicle								85
Number of vehicle leases replaced | Vehicle								85
Number of vehicle leases | Vehicle								89
Operating lease rent expenses								$ 100,000
Gain or loss recorded for leases removed								500,000
Marlborough Lease | Buildings
Commitments And Contingencies [Line Items]
Operating lease rent expenses		$ 28,895
Percentage of annual increase in lease payment		3.00%
1 Casper, LLC
Commitments And Contingencies [Line Items]
Sale price	$ 102,300,000			$ 102,300,000
Lease initial term				20 years
Lease renewal option				4 years
Lease renewal options				renewal options of five years
Lessee,option to extend [true false]				true
Operating lease costs				$ 9,500,000
Lease, description				The total annual rent under the Lease starts at approximately $9.5 million per year, subject to a 50% rent abatement during the first year of the Lease, and will increase annually by (i) 2.5% in the second through fifth year of the Lease and (ii) 3% in the sixth and each subsequent year of the Lease, including any renewal term.
Security deposit				$ 2,000,000.0
Lease repurchase description				the Company has four options to repurchase the Property, in 2026, 2031, 2036 and 2041, for the greater of (i) $102.3 million and (ii) the fair market value of the Property.
Minimum | 1 Casper, LLC
Commitments And Contingencies [Line Items]
Lease repurchase, amount				$ 102,300,000
Deerfield Management Company Lp | Milestone Rights Liability
Commitments And Contingencies [Line Items]
Contingent liability remain payable						60,000,000.0		60,000,000.0			$ 60,000,000.0
Milestone liabilities						3,900,000		3,900,000
Deerfield Management Company Lp | Milestone Rights Liability | Accrued Expenses And Other Current Liabilities
Commitments And Contingencies [Line Items]
Accrued expenses and other current liabilities						$ 900,000		$ 900,000
Deerfield Management Company Lp | Milestone Rights Liability | Maximum
Commitments And Contingencies [Line Items]
Contingent liability for milestone payments											$ 90,000,000.0
Russell Ranch Road II LLC | Office Lease
Commitments And Contingencies [Line Items]
Operating lease rent expenses			$ 79,543		$ 40,951
Percentage of annual increase in lease payment			3.00%		3.00%