| Marketable securities |
| March
31, 2019 |
|
| |
|
Cost
Basis
|
|
|
Gross
Unrealized Gains |
|
|
Gross
Unrealized Losses |
|
|
Fair
Value |
|
| Certificates
of deposit |
|
$ |
11,126,000 |
|
|
$ |
— |
|
|
$ |
— |
|
|
$ |
11,126,000 |
|
| Short
term bond funds |
|
|
11,379,000 |
|
|
|
14,000 |
|
|
|
— |
|
|
|
11,393,000 |
|
| Corporate
bonds and notes |
|
|
8,289,000 |
|
|
|
86,000 |
|
|
|
(57,000 |
) |
|
|
8,318,000 |
|
| Total
marketable securities |
|
$ |
30,794,000 |
|
|
$ |
100,000 |
|
|
$ |
(57,000 |
) |
|
$ |
30,837,000 |
|
| December
31, 2018 |
|
| |
|
Cost
Basis
|
|
|
Gross
Unrealized Gains |
|
|
Gross
Unrealized Losses |
|
|
Fair
Value |
|
| Certificates
of deposit |
|
$ |
13,151,000 |
|
|
$ |
— |
|
|
$ |
— |
|
|
$ |
13,151,000 |
|
| Short
term bond funds |
|
|
9,648,000 |
|
|
|
— |
|
|
|
(8,000 |
) |
|
|
9,640,000 |
|
| Corporate
bonds and notes |
|
|
8,518,000 |
|
|
|
— |
|
|
|
(81,000 |
) |
|
|
8,437,000 |
|
| Total
marketable securities |
|
$ |
31,317,000 |
|
|
|
— |
|
|
$ |
(89,000 |
) |
|
$ |
31,228,000 |
|
|