Commitments and Contingencies - Additional Information (Detail)			3 Months Ended
	Nov. 19, 2018 USD ($) ft²	Dec. 11, 2017 ft²	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Mar. 01, 2018 USD ($)
Other Commitments [Line Items]
Consolidated rent expense			$ 33,000	$ 42,000
Indemnification obligations			0
Expenses related to indemnification issues			$ 0
Vancouver Lease Arrangement [Member] | Vancouver, British Columbia [Member]
Other Commitments [Line Items]
Lease agreement commencement date	Feb. 01, 2019
Area of office space leased | ft²	2,367
Initial term of lease expiration date	Jan. 31, 2023
Operating lease, term of contract	4 years
Operating lease, option to extend, description			The initial term of the Vancouver Lease will expire on January 31, 2023, with an option to extend the term for one further four-year period
Lessee, Operating Lease, Existence of Option to Extend [true false]			true
Operating lease, initial monthly base rent expenses	$ 5,200
Operating lease, revised monthly base rent expenses	5,400
Construction allowance	14,200
Security deposit	$ 18,600
Seattle Lease Arrangement [Member] | Pike [Member]
Other Commitments [Line Items]
Area of office space leased | ft²		3,187
Initial term of lease expiration date		Mar. 01, 2021
Lease agreement			On December 11, 2017, we entered into a lease, or the Seattle Lease, with 520 Pike Street, Inc., or Pike, pursuant to which we leased approximately 3,187 square feet located at Suite 2250 at 520 Pike Tower, Seattle, Washington, 98101, which commenced on March 1, 2018. The Seattle Lease expired on March 1, 2021 and was not renewed.
Monthly base rent					$ 11,685,000
Monthly base rent, maximum annual increase					12,397,000
Lease, security deposit, annual payment					37,192,000
Lease, security deposit payment first anniversary					12,397,000
Lease, security deposit payment two anniversary					12,397,000
Lease, security deposit payment remaining amount					$ 12,397,000