Long-Lived Assets by Geographic Location (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Property and equipment, net	$ 2,202	$ 2,624
Operating lease ROU assets	5,133
Americas
Segment Reporting Information [Line Items]
Property and equipment, net	918	1,060
Operating lease ROU assets	4,636
Europe and the Middle East
Segment Reporting Information [Line Items]
Property and equipment, net	58	43
Operating lease ROU assets	117
Asia-Pacific
Segment Reporting Information [Line Items]
Property and equipment, net	1,226	$ 1,521
Operating lease ROU assets	$ 380