XML 39 R27.htm IDEA: XBRL DOCUMENT v3.7.0.1
Summary of Significant Accounting Policies - Summary of Marketable Securities by Security Type (Details) - USD ($)
$ in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2017
Dec. 31, 2016
Marketable Securities    
Amortized Cost $ 3,000 $ 35,216
Gross Unrealized Gains   1
Gross Unrealized Losses   (8)
Estimated Fair Value $ 3,000 $ 35,209
Maturity period for marketable securities classified as available-for-sale 1 year 1 year
United States Treasury Notes    
Marketable Securities    
Amortized Cost $ 3,000 $ 35,216
Gross Unrealized Gains   1
Gross Unrealized Losses   (8)
Estimated Fair Value $ 3,000 $ 35,209