Development Derivative Liability - Additional Information (Details)					3 Months Ended				9 Months Ended
	Mar. 31, 2020 USD ($)	Sep. 23, 2019 USD ($)	Jun. 27, 2019 USD ($)	Feb. 28, 2019 USD ($) Installment	Mar. 31, 2020 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 07, 2019 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Loss from remeasurement of development derivative liability						$ 263,000			$ 10,103,000
Development derivative liability						130,103,000			$ 130,103,000
Level 3 [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Implied cost of borrowing discount rates									16.49%
SFJ Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Proceeds from SFJ agreement			$ 20,000,000	$ 60,000,000		20,000,000	$ 40,000,000	$ 60,000,000
Additional funding amount upon achievement of development milestones		$ 20,000,000	40,000,000	$ 60,000,000
Number of milestone payments | Installment				3
Development funding for minimum period of operating expense				10 months
Increase in additional funding for development costs										$ 20,000,000
Proceeds SFJ agreement upon achievement of milestone			$ 20,000,000
Number of additional annual payments | Installment				6
Minimum payment of additional funding amount				$ 120,000,000
Increase in additional funding amount under amendment										$ 20,000,000
Loss from remeasurement of development derivative liability						263,000	$ 9,104,000	$ 736,000
Development derivative liability						$ 130,103,000			$ 130,103,000
SFJ Agreement [Member] | Level 3 [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Implied cost of borrowing discount rates									8.00%
SFJ Agreement [Member] | Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Obligated to pay initial payment				5,000,000
Aggregate amount of additional annual payments				226,000,000
SFJ Agreement [Member] | Regulatory Approval Granted by FDA and EMA
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Obligated to pay initial payment				10,000,000
SFJ Agreement [Member] | Regulatory Approval Granted by FDA and EMA | Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Aggregate amount of additional annual payments				$ 452,000,000
SFJ Agreement [Member] | Scenario Forecast [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional funding amount upon achievement of development milestones					$ 20,000,000
Additional funding for development costs	$ 50,000,000