Leases - Additional Information (Detail) $ in Thousands			1 Months Ended			2 Months Ended	3 Months Ended		6 Months Ended		17 Months Ended
	Nov. 19, 2021 USD ($) ft² Option	Oct. 23, 2020 USD ($) ft²	Mar. 31, 2020 USD ($) ft²	Apr. 30, 2019 USD ($) ft² Option	Jan. 31, 2016 ft²	Dec. 31, 2020 USD ($) ft² Option	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	May 31, 2020 USD ($) ft²
Lessee Lease Description [Line Items]
Estimated lease payments							$ 34,943		$ 34,943
Operating lease cost							1,300	$ 1,100	2,600	$ 2,000
Variable lease cost							100	200	300	500
Short-term lease cost							$ 0	$ 0	0	0
Operating lease cash payments									$ 2,200	$ 1,400
Weighted-average remaining lease term							7 years 7 months 6 days		7 years 7 months 6 days
Weighted-average discount rate							8.50%		8.50%
California | Halozyme, Inc. | Sublease Agreement
Lessee Lease Description [Line Items]
Office space leases, in square feet | ft²			21,000
Estimated lease payments			$ 2,000
Lease expiration date			Jan. 14, 2023
Sublease commencement date			Apr. 01, 2020
Corporate Headquarters In Pasadena | California
Lessee Lease Description [Line Items]
Office space leases, in square feet | ft²		24,000
Estimated lease payments		$ 6,900
Payments for leasehold improvements, net of tenant improvement allowances		$ 4,000
Lease expansion commencement period		2021-07
Lease expansion expiration month and year		2027-04
Corporate Headquarters In Pasadena | California | Colorado Owner, LLC
Lessee Lease Description [Line Items]
Lease term				91 months
Office space leases, in square feet | ft²				24,000
Lease payments, commencement date				Sep. 30, 2019
Estimated lease payments				$ 8,700
Lease expiration date				Apr. 30, 2027
Payments for leasehold improvements, net of tenant improvement allowances				$ 3,500
Operating lease renewal term				5 years
Number of options to renew | Option				1
Research Facility in Madison | Wisconsin
Lessee Lease Description [Line Items]
Office space leases, in square feet | ft²					60,000
Estimated lease payments						$ 1,200					$ 26,200
Lease expiration date					Sep. 30, 2026						Sep. 30, 2031
Operating lease renewal term						5 years
Number of options to renew | Option						2
Additional office space for lease | ft²						10,743					40,000
Expected leasehold improvements, net of tenant improvement allowances											$ 11,000
Research Facility in San Diego | California
Lessee Lease Description [Line Items]
Lease term	15 years
Office space leases, in square feet | ft²	144,000
Lease payments, commencement date	May 31, 2023
Estimated lease payments	$ 119,000
Payments for leasehold improvements, net of tenant improvement allowances	$ 31,000
Operating lease renewal term	10 years
Estimated payments for operating expenses	$ 3,000
Research Facility in San Diego | California | Maximum
Lessee Lease Description [Line Items]
Number of options to renew | Option	1