Segments and Geographic Information - Selected Information by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 20,930	$ 11,556	$ 11,610	$ 10,477	$ 8,625	$ 10,993	$ 9,633	$ 9,036	$ 54,573	$ 38,287	$ 33,393
Total assets	57,571				50,577				57,571	50,577
Total Long-lived assets	14,502				14,633				14,502	14,633
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									19,955	7,677	10,374
Total assets	21,423				15,454				21,423	15,454
Total Long-lived assets	663				765				663	765
Switzerland [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									27,302	23,139	18,789
Total assets	4,673				1,570				4,673	1,570
Total Long-lived assets	369				49				369	49
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									4,632	4,422	2,180
Total assets	31,288				33,335				31,288	33,335
Total Long-lived assets	13,468				13,817				13,468	13,817
Other Countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									2,684	3,049	2,050
Total assets	187				218				187	218
Total Long-lived assets	$ 2				$ 2				2	2
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									$ 34,618	$ 30,610	$ 23,019