Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Summary of Fair Value Measurements (Detail)

v3.8.0.1
Summary of Significant Accounting Policies - Summary of Fair Value Measurements (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Asset at Fair Value:    
Total Assets at Fair Value $ 3 $ 9
Liabilities at Fair Value    
Total Liabilities at Fair Value 4 19
Forward Purchase Contracts [Member]    
Asset at Fair Value:    
Forward purchase contracts 3 9
Liabilities at Fair Value    
Forward purchase contracts 4 19
Level 2 [Member]    
Asset at Fair Value:    
Total Assets at Fair Value 3 9
Liabilities at Fair Value    
Total Liabilities at Fair Value 4 19
Level 2 [Member] | Forward Purchase Contracts [Member]    
Asset at Fair Value:    
Forward purchase contracts 3 9
Liabilities at Fair Value    
Forward purchase contracts $ 4 $ 19