Segment Information (Revenue by Geographic Region) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 11,708	$ 14,332	$ 36,840	$ 44,781
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	7,004	9,227	23,428	28,368
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	1,993	2,155	6,034	6,746
Rest of the World
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 2,711	$ 2,950	$ 7,378	$ 9,667