Long-Lived Assets by Geographic Location (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Property and equipment, net	$ 2,425	$ 2,624
Operating lease ROU assets	5,525
Americas
Segment Reporting Information [Line Items]
Property and equipment, net	1,061	1,060
Operating lease ROU assets	4,880
Europe and the Middle East
Segment Reporting Information [Line Items]
Property and equipment, net	28	43
Operating lease ROU assets	142
Asia-Pacific
Segment Reporting Information [Line Items]
Property and equipment, net	1,336	$ 1,521
Operating lease ROU assets	$ 503