| Schedule of fair value of financial instruments measured on a recurring basis |
|
|
|
December 31, 2013
|
|
|
|
|
Adjusted
Cost
|
|
Unrealized
Gains
|
|
Unrealized
Losses
|
|
Fair Value
|
|
Cash and
Cash
Equivalents
|
|
Short-term
Investments
|
|
Long-term
Investments
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Cash
|
|
$
|
5,533
|
|
$
|
—
|
|
$
|
—
|
|
$
|
5,533
|
|
$
|
5,533
|
|
$
|
—
|
|
$
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Level 1:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Money market funds
|
|
79,013
|
|
—
|
|
—
|
|
79,013
|
|
79,013
|
|
—
|
|
—
|
|
|
Subtotal
|
|
79,013
|
|
—
|
|
—
|
|
79,013
|
|
79,013
|
|
—
|
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total
|
|
$
|
84,546
|
|
$
|
—
|
|
$
|
—
|
|
$
|
84,546
|
|
$
|
84,546
|
|
$
|
—
|
|
$
|
—
|
|
|
|
|
December 31, 2014
|
|
|
|
|
Adjusted
Cost
|
|
Unrealized
Gains
|
|
Unrealized
Losses
|
|
Fair Value
|
|
Cash and
Cash
Equivalents
|
|
Short-term
Investments
|
|
Long-term
Investments
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Cash
|
|
$
|
13,077
|
|
$
|
—
|
|
$
|
—
|
|
$
|
13,077
|
|
$
|
13,077
|
|
$
|
—
|
|
$
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Level 1:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Money market funds
|
|
16,110
|
|
—
|
|
—
|
|
16,110
|
|
16,110
|
|
—
|
|
—
|
|
|
Subtotal
|
|
16,110
|
|
—
|
|
—
|
|
16,110
|
|
16,110
|
|
—
|
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Level 2:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Asset-backed securities
|
|
4,458
|
|
—
|
|
(3
|
)
|
4,455
|
|
—
|
|
—
|
|
4,455
|
|
|
Corporate bonds
|
|
54,321
|
|
2
|
|
(46
|
)
|
54,277
|
|
—
|
|
46,726
|
|
7,551
|
|
|
Commercial paper
|
|
6,797
|
|
—
|
|
—
|
|
6,797
|
|
—
|
|
6,797
|
|
—
|
|
|
U.S. agency securities
|
|
2,503
|
|
—
|
|
—
|
|
2,503
|
|
—
|
|
—
|
|
2,503
|
|
|
Subtotal
|
|
68,079
|
|
2
|
|
(49
|
)
|
68,032
|
|
—
|
|
53,523
|
|
14,509
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total
|
|
$
|
97,266
|
|
$
|
2
|
|
$
|
(49
|
)
|
$
|
97,219
|
|
$
|
29,187
|
|
$
|
53,523
|
|
$
|
14,509
|
|
|