Quarterly report pursuant to Section 13 or 15(d)

Cash, Cash Equivalents, and Short-Term Investments - Schedule of Short-term Investments (Details)

v3.8.0.1
Cash, Cash Equivalents, and Short-Term Investments - Schedule of Short-term Investments (Details) - USD ($)
$ in Thousands
Sep. 30, 2017
Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]    
Aggregated Cost Basis $ 0 $ 34,098
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 (79)
Aggregated Fair Value 0 34,019
U.S. investment grade bonds    
Schedule of Available-for-sale Securities [Line Items]    
Aggregated Cost Basis 0 24,531
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 (54)
Aggregated Fair Value 0 24,477
Foreign investment grade bonds    
Schedule of Available-for-sale Securities [Line Items]    
Aggregated Cost Basis 0 9,567
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 (25)
Aggregated Fair Value $ 0 $ 9,542