| Schedule of Available-for-sale Investments |
Available-for-sale investments consisted of the following as of September 30, 2020 and December 31, 2019 (in thousands):
|
|
|
September 30, 2020 |
|
|
|
|
Amortized
Cost |
|
|
Unrealized
Gain |
|
|
Unrealized
Loss |
|
|
Estimated
Fair Value |
|
|
Short-term marketable securities |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
U.S. government debt and agency securities |
|
$ |
323,338 |
|
|
$ |
1,034 |
|
|
$ |
(2 |
) |
|
$ |
324,370 |
|
|
Corporate bonds |
|
|
13,502 |
|
|
|
134 |
|
|
|
(2 |
) |
|
|
13,634 |
|
|
Total short-term marketable securities |
|
$ |
336,840 |
|
|
$ |
1,168 |
|
|
$ |
(4 |
) |
|
$ |
338,004 |
|
|
Long-term marketable securities |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
U.S. government debt and agency securities |
|
$ |
16,203 |
|
|
$ |
263 |
|
|
$ |
— |
|
|
$ |
16,466 |
|
|
Total long-term marketable securities |
|
$ |
16,203 |
|
|
$ |
263 |
|
|
$ |
— |
|
|
$ |
16,466 |
|
|
|
|
December 31, 2019 |
|
|
|
|
Amortized
Cost |
|
|
Unrealized
Gain |
|
|
Unrealized
Loss |
|
|
Estimated
Fair Value |
|
|
Short-term marketable securities |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Commercial paper |
|
$ |
121,866 |
|
|
$ |
— |
|
|
$ |
— |
|
|
$ |
121,866 |
|
|
U.S. government debt and agency securities |
|
|
285,963 |
|
|
|
394 |
|
|
|
(1 |
) |
|
|
286,356 |
|
|
Corporate bonds |
|
|
71,962 |
|
|
|
109 |
|
|
|
(3 |
) |
|
|
72,068 |
|
|
Total short-term marketable securities |
|
$ |
479,791 |
|
|
$ |
503 |
|
|
$ |
(4 |
) |
|
$ |
480,290 |
|
|
Long-term marketable securities |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
U.S. government debt and agency securities |
|
$ |
90,750 |
|
|
$ |
146 |
|
|
$ |
(9 |
) |
|
$ |
90,887 |
|
|
Corporate bonds |
|
|
14,513 |
|
|
|
35 |
|
|
|
— |
|
|
|
14,548 |
|
|
Total long-term marketable securities |
|
$ |
105,263 |
|
|
$ |
181 |
|
|
$ |
(9 |
) |
|
$ |
105,435 |
|
|
| Schedule of Gross Unrealized Holding Losses and Fair Value for Investments in Unrealized Loss Position |
The following table presents the gross unrealized holding losses and fair value for investments in an unrealized loss position, and the length of time that individual securities have been in a continuous loss position, as of September 30, 2020 (in thousands):
|
|
|
Less Than 12 Months |
|
|
12 Months Or Greater |
|
|
|
|
Fair
Value |
|
|
Unrealized
Loss |
|
|
Fair
Value |
|
|
Unrealized
Loss |
|
|
U.S. government debt and agency securities |
|
$ |
75,564 |
|
|
$ |
(2 |
) |
|
$ |
— |
|
|
$ |
— |
|
|
Corporate bonds |
|
|
1,522 |
|
|
|
(2 |
) |
|
|
— |
|
|
|
— |
|
|
Total available-for-sale securities |
|
$ |
77,086 |
|
|
$ |
(4 |
) |
|
$ |
— |
|
|
$ |
— |
|
|