| Summary of Estimated Fair Value and Related Valuation Input Hierarchy of Available-for-Sale Securities |
The following tables summarize the estimated fair value and related valuation input hierarchy of our available-for-sale securities as of each period end:
|
|
|
|
|
Total
|
|
|
Total
|
|
|
Total
|
|
|
Total
|
|
|
|
|
|
|
Amortized
|
|
|
Unrealized
|
|
|
Unrealized
|
|
|
Estimated
|
|
|
As of March 31, 2018:
|
|
Input Level
|
|
Cost
|
|
|
Gain
|
|
|
Loss
|
|
|
Fair Value
|
|
|
|
|
|
|
(in thousands)
|
|
|
Money market funds
|
|
Level 1
|
|
$
|
47,411
|
|
|
$
|
-
|
|
|
$
|
-
|
|
|
$
|
47,411
|
|
|
U.S. Treasury obligations
|
|
Level 2
|
|
|
157,156
|
|
|
|
1
|
|
|
|
(125
|
)
|
|
|
157,032
|
|
|
Government agency obligations
|
|
Level 2
|
|
|
8,481
|
|
|
|
-
|
|
|
|
(38
|
)
|
|
|
8,443
|
|
|
Corporate debt obligations
|
|
Level 2
|
|
|
142,148
|
|
|
|
5
|
|
|
|
(340
|
)
|
|
|
141,813
|
|
|
Commercial paper
|
|
Level 2
|
|
|
31,828
|
|
|
|
-
|
|
|
|
-
|
|
|
|
31,828
|
|
|
Asset-backed securities
|
|
Level 2
|
|
|
15,309
|
|
|
|
1
|
|
|
|
(28
|
)
|
|
|
15,282
|
|
|
Certificate of deposit
|
|
Level 2
|
|
|
1,500
|
|
|
|
-
|
|
|
|
-
|
|
|
|
1,500
|
|
|
Total available-for-sale securities
|
|
|
|
|
403,833
|
|
|
|
7
|
|
|
|
(531
|
)
|
|
|
403,309
|
|
|
Less amounts classified as cash equivalents
|
|
|
|
|
(86,485
|
)
|
|
|
—
|
|
|
|
2
|
|
|
|
(86,483
|
)
|
|
Amounts classified as short-term investments
|
|
|
|
$
|
317,348
|
|
|
$
|
7
|
|
|
$
|
(529
|
)
|
|
$
|
316,826
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total
|
|
|
Total
|
|
|
Total
|
|
|
Total
|
|
|
|
|
|
|
Amortized
|
|
|
Unrealized
|
|
|
Unrealized
|
|
|
Estimated
|
|
|
As of December 31, 2017:
|
|
Input Level
|
|
Cost
|
|
|
Gain
|
|
|
Loss
|
|
|
Fair Value
|
|
|
|
|
|
|
(in thousands)
|
|
|
Money market funds
|
|
Level 1
|
|
$
|
68,730
|
|
|
$
|
—
|
|
|
$
|
—
|
|
|
$
|
68,730
|
|
|
U.S. Treasury obligations
|
|
Level 2
|
|
|
39,068
|
|
|
|
—
|
|
|
|
(28
|
)
|
|
|
39,040
|
|
|
Government agency obligations
|
|
Level 2
|
|
|
4,749
|
|
|
|
—
|
|
|
|
(21
|
)
|
|
|
4,728
|
|
|
Corporate debt obligations
|
|
Level 2
|
|
|
46,532
|
|
|
|
2
|
|
|
|
(98
|
)
|
|
|
46,436
|
|
|
Commercial paper
|
|
Level 2
|
|
|
1,592
|
|
|
|
—
|
|
|
|
—
|
|
|
|
1,592
|
|
|
Asset-backed securities
|
|
Level 2
|
|
|
4,122
|
|
|
|
—
|
|
|
|
(6
|
)
|
|
|
4,116
|
|
|
Total available-for-sale securities
|
|
|
|
|
164,793
|
|
|
|
2
|
|
|
|
(153
|
)
|
|
|
164,642
|
|
|
Less amounts classified as cash equivalents
|
|
|
|
|
(77,769
|
)
|
|
|
—
|
|
|
|
—
|
|
|
|
(77,769
|
)
|
|
Amounts classified as short-term investments
|
|
|
|
$
|
87,024
|
|
|
$
|
2
|
|
|
$
|
(153
|
)
|
|
$
|
86,873
|
|
|
| Amortized Cost and Fair Value of Available for Sale Securities by Contractual Maturity |
The amortized cost and fair value of our available-for-sale securities by contractual maturity were as follows:
|
|
As of March 31, 2018
|
|
|
As of December 31, 2017
|
|
|
|
Amortized
|
|
|
Estimated
|
|
|
Amortized
|
|
|
Estimated
|
|
|
|
Cost
|
|
|
Fair Value
|
|
|
Cost
|
|
|
Fair Value
|
|
|
|
(in thousands)
|
|
|
(in thousands)
|
|
|
Maturing within one year
|
$
|
334,088
|
|
|
$
|
333,774
|
|
|
$
|
151,938
|
|
|
$
|
151,852
|
|
|
Maturing in one to five years
|
|
69,745
|
|
|
|
69,535
|
|
|
|
12,855
|
|
|
|
12,790
|
|
|
Total available-for-sale securities
|
$
|
403,833
|
|
|
$
|
403,309
|
|
|
$
|
164,793
|
|
|
$
|
164,642
|
|
|
| Reconciliation of Cash, Cash Equivalents and Restricted Cash |
The following table provides a reconciliation of cash, cash equivalents and restricted cash within the condensed consolidated balance sheets that sum to the total of the same such amounts in the condensed consolidated statement of cash flows:
|
|
|
March 31,
|
|
|
December 31,
|
|
|
|
|
2018
|
|
|
2017
|
|
|
|
|
(in thousands)
|
|
|
Cash and cash equivalents
|
|
|
90,495
|
|
|
|
79,223
|
|
|
Restricted cash - short term
|
|
|
194
|
|
|
|
194
|
|
|
Restricted cash - long term
|
|
|
1,200
|
|
|
|
1,200
|
|
|
Total cash, cash equivalents and restricted cash
|
|
$
|
91,889
|
|
|
$
|
80,617
|
|
|