Investment securities, all classified as available-for-sale, consisted of the following (in thousands):
|
|
June 30, 2017 |
|
|
|
Amortized
Cost |
|
|
Unrealized
Gains |
|
|
Unrealized
Losses |
|
|
Estimated
Fair
Value |
|
U.S. Treasury notes |
|
$ |
31,794 |
|
|
$ |
— |
|
|
$ |
(11 |
) |
|
$ |
31,783 |
|
Government sponsored enterprise securities |
|
|
62,079 |
|
|
|
— |
|
|
|
(29 |
) |
|
|
62,050 |
|
Corporate debt securities |
|
|
53,012 |
|
|
|
— |
|
|
|
(22 |
) |
|
|
52,990 |
|
Commercial paper |
|
|
126,753 |
|
|
|
2 |
|
|
|
(47 |
) |
|
|
126,708 |
|
|
|
$ |
273,638 |
|
|
$ |
2 |
|
|
$ |
(109 |
) |
|
$ |
273,531 |
|
|
|
December 31, 2016 |
|
|
|
Amortized
Cost |
|
|
Unrealized
Gains |
|
|
Unrealized
Losses |
|
|
Estimated
Fair
Value |
|
U.S. Treasury notes |
|
$ |
82,484 |
|
|
$ |
6 |
|
|
$ |
(3 |
) |
|
$ |
82,487 |
|
Government sponsored enterprise securities |
|
|
73,789 |
|
|
|
1 |
|
|
|
(5 |
) |
|
|
73,785 |
|
Corporate debt securities |
|
|
79,190 |
|
|
|
— |
|
|
|
(72 |
) |
|
|
79,118 |
|
Commercial paper |
|
|
129,861 |
|
|
|
165 |
|
|
|
— |
|
|
|
130,026 |
|
|
|
$ |
365,324 |
|
|
$ |
172 |
|
|
$ |
(80 |
) |
|
$ |
365,416 |
|
|