Subsequent Events - Additional Information (Detail) - Subsequent Event [Member]	Aug. 04, 2017 USD ($) ft²	Jul. 24, 2017 USD ($)
ARE-San Francisco No. 19, LLC [Member]
Subsequent Event [Line Items]
Lease space | ft²	128,793
Lease commencement date	Feb. 01, 2020
Lease expiration date	Jan. 31, 2030
Lease, monthly base rent	$ 611,767
Lease, annual rent adjustment rate	3.00%
Additional lease space | ft²	24,000
Nektar's [Member] | NKTR-358 [Member]
Subsequent Event [Line Items]
Percentage of sharing in Phase 2 development costs		25.00%
Eli Lilly and Company [Member] | NKTR-358 [Member]
Subsequent Event [Line Items]
Initial payment receivable		$ 150,000,000
Percentage of sharing in Phase 2 development costs		75.00%
Eli Lilly and Company [Member] | NKTR-358 [Member] | Maximum [Member]
Subsequent Event [Line Items]
Potential future additional development and regulatory milestones		$ 250,000,000
Pfizer, Inc. [Member]
Subsequent Event [Line Items]
Sublease, maximum termination period	2020-01