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Licenses, Asset Acquisitions and Contingent Consideration - Additional Information (Details) - USD ($)						1 Months Ended					3 Months Ended		9 Months Ended
	May 11, 2020	Sep. 21, 2018	Jun. 24, 2018	Jan. 04, 2018	Oct. 02, 2017	May 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Business Acquisition [Line Items]
In process research and development								$ 20,000,000.0			$ 275,000	$ 0	$ 18,080,000	$ 2,000,000
GB002
Business Acquisition [Line Items]
In process research and development											0	0	0	0
GB001
Business Acquisition [Line Items]
In process research and development											0	0	0	0
GB004
Business Acquisition [Line Items]
In process research and development											275,000	0	15,275,000	0
GB1275
Business Acquisition [Line Items]
In process research and development											0	$ 0	0	$ 1,000,000
Pulmokine, Inc. | License Agreement | GB002
Business Acquisition [Line Items]
Product license term					10 years
Upfront payment										$ 5,500,000
Milestones accrued											0		0
Pulmokine, Inc. | License Agreement | GB002 | Maximum
Business Acquisition [Line Items]
Development and regulatory milestone payments, payable					$ 63,000,000.0
Commercial milestone payments, payable					45,000,000.0
Sales milestone payments, payable					$ 190,000,000.0
AA Biopharma Inc. | GB001
Business Acquisition [Line Items]
In process research and development									$ 19,300,000
AA Biopharma Inc. | GB001 | Common stock
Business Acquisition [Line Items]
Business acquisition, aggregate number of shares issued (in shares)				1,101,278
AA Biopharma Inc. | GB001 | Series Seed Convertible Preferred Stock
Business Acquisition [Line Items]
Business acquisition, aggregate number of shares issued (in shares)				20,000,000
Aerpio Pharmaceuticals, Inc. | License Agreement | GB004
Business Acquisition [Line Items]
Upfront payment	$ 15,000,000.0
Milestones accrued											0		0
Participation rights			20.00%
Aerpio Pharmaceuticals, Inc. | License Agreement | GB004 | Maximum
Business Acquisition [Line Items]
Development and regulatory milestone payments, payable	40,000,000.0
Sales milestone payments, payable	$ 50,000,000.0
Adhaere Pharmaceuticals, Inc. | GB1275
Business Acquisition [Line Items]
Milestones accrued											$ 0		$ 0
In process research and development							$ 7,500,000
Upfront payment, purchase consideration paid		$ 7,500,000
Milestones payment						$ 1,000,000.0
Adhaere Pharmaceuticals, Inc. | GB1275 | Maximum
Business Acquisition [Line Items]
Regulatory, development and sales milestone payments payable		$ 62,000,000.0

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