Cash, Cash Equivalents and Marketable Securities - Amortized Cost and Fair Value (Details) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
---|---|---|
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | $ 50,058 | $ 62,908 |
Gross Unrealized Gains | 2 | 1 |
Gross Unrealized Losses | (96) | (59) |
Fair Value | 49,964 | 62,850 |
Corporate debt securities | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 35,869 | 61,108 |
Gross Unrealized Gains | 2 | 1 |
Gross Unrealized Losses | (72) | (59) |
Fair Value | 35,799 | 61,050 |
U.S. government agency securities | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 10,544 | |
Gross Unrealized Gains | 0 | |
Gross Unrealized Losses | (24) | |
Fair Value | 10,520 | 0 |
Commercial paper | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 3,645 | 1,800 |
Gross Unrealized Gains | 0 | 0 |
Gross Unrealized Losses | 0 | 0 |
Fair Value | $ 3,645 | $ 1,800 |