Commitments and Contingencies - Additional Information (Detail) $ in Millions		1 Months Ended					9 Months Ended
	Sep. 10, 2019 Patent	May 31, 2019 ft²	Jun. 30, 2018	Apr. 30, 2018 ft²	Jun. 30, 2014 ft²	Apr. 30, 2008 ft²	Sep. 30, 2020 USD ($)
Operating Leased Assets [Line Items]
Weighted-average remaining lease term							4 years 9 months 18 days
Weighted-average discount rate							7.70%
Number of patents infringes | Patent	2
Purchase commitments | $							$ 1.6
Lease Agreement | Oakwood Village, Ohio
Operating Leased Assets [Line Items]
Area of land						19,800
Lease agreement, expiration date						2021-10
Lease Agreement | Mountain View, California
Operating Leased Assets [Line Items]
Area of land				24,600	25,500
Lease agreement, expiration date			2025-07	2025-12	2019-11
Option to extend, description operating lease							extend the term of the lease agreement through July 2025
Option to extend, existence operating Lease				true			true
Lease commencement date				2018-12
Lease Agreement | Mountain View, California | Maximum
Operating Leased Assets [Line Items]
Lease agreement, renewal term				5 years
Sub-Lease Agreement | Denver, Colorado
Operating Leased Assets [Line Items]
Area of land		19,800
Lease agreement, expiration date		2021-07
Lease commencement date		2019-06