XML 46 R35.htm IDEA: XBRL DOCUMENT v3.8.0.1
Available-for-Sale Securities (Details) - USD ($)
$ in Thousands
9 Months Ended
Sep. 30, 2017
Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost $ 16,498  
Aggregate Fair Value $ 16,499  
Maximum number of months available-for-sale securities in a continuous unrealized loss position 12 months  
Available for sale securities in a continuous unrealized loss position    
Schedule Of Available For Sale Securities [Line Items]    
Available-for-sale Securities $ 0  
U.S. treasury securities    
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost 16,498 $ 50,004
Gross Unrealized Gains 1  
Gross Unrealized Losses   (7)
Aggregate Fair Value $ 16,499 $ 49,997