| Marketable Securities |
4. Marketable Securities
Marketable securities, which are classified as available-for-sale, consisted of the following as of March 31, 2018:
|
|
|
|
|
|
|
|
Amortized
Cost Basis |
|
|
Unrealized
Gains |
|
|
Unrealized
Losses |
|
|
Fair
Value |
|
|
|
|
(in thousands) |
|
|
Short-term marketable securities: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Commercial paper |
|
$ |
5,445 |
|
|
$ |
— |
|
|
$ |
(17 |
) |
|
$ |
5,428 |
|
|
Corporate debt securities |
|
|
10,167 |
|
|
|
— |
|
|
|
(27 |
) |
|
|
10,140 |
|
|
Asset-backed securities |
|
|
14,446 |
|
|
|
— |
|
|
|
(42 |
) |
|
|
14,404 |
|
|
U.S. government debt securities |
|
|
41,361 |
|
|
|
— |
|
|
|
(52 |
) |
|
|
41,309 |
|
|
Total short term marketable securities |
|
$ |
71,419 |
|
|
$ |
— |
|
|
$ |
(138 |
) |
|
$ |
71,281 |
|
Marketable securities, which are classified as available-for-sale, consisted of the following as of December 31, 2017:
|
|
|
|
|
|
|
|
Amortized
Cost Basis |
|
|
Unrealized
Gains |
|
|
Unrealized
Losses |
|
|
Fair
Value |
|
|
|
|
(in thousands) |
|
|
Short-term marketable securities: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Commercial paper |
|
$ |
6,369 |
|
|
$ |
— |
|
|
$ |
(10 |
) |
|
$ |
6,359 |
|
|
Corporate debt securities |
|
|
16,162 |
|
|
|
— |
|
|
|
(13 |
) |
|
|
16,149 |
|
|
Asset-backed securities |
|
|
14,604 |
|
|
|
— |
|
|
|
(16 |
) |
|
|
14,588 |
|
|
U.S. government debt securities |
|
|
42,172 |
|
|
|
— |
|
|
|
(56 |
) |
|
|
42,116 |
|
|
Total short-term marketable securities |
|
|
79,307 |
|
|
|
— |
|
|
|
(95 |
) |
|
|
79,212 |
|
|
Long-term marketable securities: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Asset-backed securities |
|
|
2,752 |
|
|
|
— |
|
|
|
(10 |
) |
|
|
2,742 |
|
|
U.S. government debt securities |
|
|
2,375 |
|
|
|
1 |
|
|
|
— |
|
|
|
2,376 |
|
|
Total long-term marketable securities |
|
|
5,127 |
|
|
|
1 |
|
|
|
(10 |
) |
|
|
5,118 |
|
|
Total marketable securities |
|
$ |
84,434 |
|
|
$ |
1 |
|
|
$ |
(105 |
) |
|
$ |
84,330 |
|
At March 31, 2018, the remaining contractual maturities of available-for-sale securities were less than two years. There have been no significant realized gains or losses on available-for-sale securities for the periods presented. Available-for-sale debt securities that were in a continuous loss position but were not deemed to be other than temporarily impaired were immaterial at both March 31, 2018 and December 31, 2017.
|