XML 76 R61.htm IDEA: XBRL DOCUMENT v3.8.0.1
Segment Information and Geographic Data - Long Lived Assets by Geographical Region (Detail) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Segment Reporting Information [Line Items]    
Total long lived assets $ 47,734 $ 43,294
Americas [Member]    
Segment Reporting Information [Line Items]    
Total long lived assets 30,783 29,764
Europe [Member]    
Segment Reporting Information [Line Items]    
Total long lived assets 14,802 11,257
Asia Pacific [Member]    
Segment Reporting Information [Line Items]    
Total long lived assets $ 2,149 $ 2,273
Outside Of Americas [Member] | Assets Total [Member] | Geographic Concentration Risk [Member]    
Segment Reporting Information [Line Items]    
Percentage of long lived assets held outside of the Americas 36.00% 31.00%