Commitments and Contingencies - Additional Information (Detail) $ in Millions			1 Months Ended	12 Months Ended
	Mar. 03, 2021 ft²	Sep. 10, 2019 Patent	Apr. 30, 2018 ft²	Dec. 31, 2020 USD ($) ft²	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Operating Leased Assets [Line Items]
Weighted-average remaining lease term				4 years 8 months 12 days
Weighted-average discount rate				7.70%
Operating lease cost | $				$ 3.1	$ 2.9
Rent expense | $						$ 1.4
Number of patents infringes | Patent		2
Purchase commitments | $				$ 2.3
Lease Agreement | Oakwood Village, Ohio
Operating Leased Assets [Line Items]
Area of land				19,800
Lease agreement, expiration date				2026-10
Lease Agreement | Mountain View, California
Operating Leased Assets [Line Items]
Area of land			24,600	25,500
Lease agreement, expiration date			2025-12	2025-07
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
Sub-Lease Agreement | Denver, Colorado | Subsequent Event
Operating Leased Assets [Line Items]
Area of land	12,800
Lease commencement date	Sep. 01, 2021
Lease agreement, expiration date	Oct. 31, 2024