Commitments and Contingencies - Additional Information (Detail) $ / shares in Units, € in Millions						3 Months Ended			9 Months Ended			24 Months Ended
	Apr. 05, 2018 USD ($) $ / shares shares	Apr. 02, 2018 EUR (€)	Nov. 29, 2017 USD ($)	Oct. 23, 2017 shares	May 05, 2017 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) Vehicle	Sep. 30, 2018 EUR (€) Vehicle	Sep. 30, 2017 USD ($)	Oct. 01, 2018 USD ($)	Sep. 30, 2018 EUR (€)	Mar. 08, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jul. 01, 2013 USD ($)
Commitments And Contingencies [Line Items]
Purchase commitment amount under Insulin Supply Agreement | €										€ 85.8
Purchase obligation included in accounts payable															$ 1,600,000
Supply Agreement expiration period									Dec. 31, 2023	Dec. 31, 2023
Supply Agreement renewal period									2 years	2 years
Purchase requirement amount for remaining current year | €													€ 4.4
Realized currency loss						$ (728,000)		$ 3,684,000	$ (3,107,000)		$ 12,077,000
Amount of net proceeds from issuance of securities									819,000
Operating lease rent expenses						$ 100,000			$ 400,000
Lease Agreement with Enterprise | Vehicle Leases
Commitments And Contingencies [Line Items]
Number of vehicle leases | Vehicle									100	100
Operating lease rent expenses									$ 54,000
Lease commencement period									second quarter of 2018	second quarter of 2018
Lease expiration period						48 months			48 months				48 months
Common Stock
Commitments And Contingencies [Line Items]
Number of shares sold in underwritten public offering | shares				973,236
Purchase Agreements
Commitments And Contingencies [Line Items]
Stock purchase agreements date	Apr. 05, 2018
Purchase Agreements | Common Stock
Commitments And Contingencies [Line Items]
Number of shares sold in underwritten public offering | shares	14,000,000
Amount of net proceeds from issuance of securities	$ 26,400,000
Exchange price per share | $ / shares	$ 2.00
Purchase Agreements | Warrants
Commitments And Contingencies [Line Items]
Warrants to purchase of common stock | shares	14,000,000
Exercise price of warrants | $ / shares	$ 2.38
Supply Commitment
Commitments And Contingencies [Line Items]
Purchase commitment obligation						$ 100,000			$ 100,000
Foreign Currency Hedging Transaction
Commitments And Contingencies [Line Items]
Purchase requirement amount for remaining current year | €		€ 4.4
Foreign currency hedging transaction renewable period		90 days
Foreign Currency Hedging Transaction | Cost of Goods Sold
Commitments And Contingencies [Line Items]
Realized currency loss						100,000	$ 500,000
Scenario Forecast
Commitments And Contingencies [Line Items]
Purchase commitment cancellation fees												$ 3,400,000
Scenario Forecast | Before Amendment
Commitments And Contingencies [Line Items]
Purchase commitment cancellation fees												$ 5,300,000
Standby Letter of Credit | Vehicle Leases
Commitments And Contingencies [Line Items]
Maximum borrowing capacity														$ 500,000
Collateralized amount under letter of credit														$ 500,000
Amount drawn down on letter of credit						0			0
Deerfield | Milestone Rights Liability
Commitments And Contingencies [Line Items]
Contingent liability for milestone payments, remain payable amount						75,000,000			75,000,000							$ 75,000,000
Deerfield | Milestone Rights Liability | Maximum
Commitments And Contingencies [Line Items]
Contingent liability for milestone payments						$ 90,000,000			$ 90,000,000							$ 90,000,000
Russell Ranch Road II LLC
Commitments And Contingencies [Line Items]
Operating lease rent expenses			$ 35,969		$ 40,951
Percentage of annual increase in lease payment			3.00%		3.00%
Lease expiration date			Jan. 31, 2023		Jan. 31, 2023
Lease renewal option			5 years		5 years
Maximum reimbursable amount for tenant improvements			$ 56,325