Segment Information (Revenue by Geographic Region) (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	[1]	$ 39,472	$ 19,650
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue		18,970	11,434
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue		15,384	3,025
Rest of the World
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue		$ 5,118	$ 5,191

[1] Quarters ended March 31, Components of Revenue2019 2018License Fees3,541 7,414Service Revenue35,931 12,236Net Revenue39,472 19,650 Three Months Ended March 31, Components of Revenue2019 2018License Fees$3,541 $7,414Service Revenue35,931 12,236Net Revenue$39,472 $19,650