Commitments and Contingencies - Additional Information (Detail) $ in Thousands					12 Months Ended
	Jan. 07, 2017 USD ($) ft²	Dec. 22, 2016 ft²	Nov. 01, 2016 ft²	Jan. 01, 2016 ft²	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Contingencies And Commitments [Line Items]
Deferred rent liability					$ 150
Operating lease obligation, annual basic rent for first year					559
Operating lease obligation, annual basic rent for second year					569
Operating lease costs					$ 370	$ 154	$ 188
Sublease rentals							$ 127
CANADA
Contingencies And Commitments [Line Items]
Lease agreement, commencement date		Dec. 22, 2016	Nov. 01, 2016
Lease agreement, expiration date		Jun. 30, 2019	Oct. 31, 2021
Lease agreement extended period			Oct. 31, 2026
Square feet of office space leased | ft²		2,500	10,946
CALIFORNIA
Contingencies And Commitments [Line Items]
Lease agreement, commencement date				Jan. 01, 2016
Lease agreement, expiration date				Dec. 31, 2018
Square feet of office space leased | ft²				3,520
CALIFORNIA | Subsequent Event [Member]
Contingencies And Commitments [Line Items]
Lease agreement, commencement date	Feb. 01, 2017
Lease agreement, expiration date	Dec. 31, 2018
Square feet of office space leased | ft²	6,019
Operating lease obligation, annual basic rent for first year	$ 203
Operating lease obligation, annual basic rent for second year	$ 278