|
Investments (Details) (USD $)
|
3 Months Ended |
12 Months Ended |
|
Dec. 31, 2014
|
Sep. 30, 2014
|
Jun. 30, 2014
|
Mar. 31, 2014
|
Dec. 31, 2013
|
Sep. 30, 2013
|
Jun. 30, 2013
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Mar. 31, 2013
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Dec. 31, 2014
|
Dec. 31, 2013
|
Dec. 31, 2012
|
| Cash equivalents and investments |
|
|
|
|
|
|
|
|
|
|
|
| Gross Unrealized Gains |
$ 4,000 |
|
|
|
$ 4,000 |
|
|
|
$ 4,000 |
$ 4,000 |
|
| Gross Unrealized Losses |
(63,000) |
|
|
|
(7,000) |
|
|
|
(63,000) |
(7,000) |
|
| Total, Amortized Cost |
56,960,000 |
|
|
|
26,422,000 |
|
|
|
56,960,000 |
26,422,000 |
|
| Total, Estimated Fair Value |
56,901,000 |
|
|
|
26,419,000 |
|
|
|
56,901,000 |
26,419,000 |
|
| Other income (expense), net |
57,000 |
29,000 |
17,000 |
16,000 |
46,000 |
169,000 |
4,000 |
(25,000) |
119,000 |
194,000 |
(84,000) |
| Reclassification out of accumulated other comprehensive income (loss) |
|
|
|
|
|
|
|
|
|
|
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| Cash equivalents and investments |
|
|
|
|
|
|
|
|
|
|
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| Other income (expense), net |
|
|
|
|
|
|
|
|
0 |
|
|
| Short-term investments. | U.S. treasury notes |
|
|
|
|
|
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|
|
|
|
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| Cash equivalents and investments |
|
|
|
|
|
|
|
|
|
|
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| Investments, Amortized Cost |
9,020,000 |
|
|
|
2,071,000 |
|
|
|
9,020,000 |
2,071,000 |
|
| Gross Unrealized Gains |
4,000 |
|
|
|
|
|
|
|
4,000 |
|
|
| Investments, Estimated Fair Value |
9,024,000 |
|
|
|
2,071,000 |
|
|
|
9,024,000 |
2,071,000 |
|
| Short-term investments. | U.S. government agency securities |
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|
|
|
|
|
|
|
|
|
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| Cash equivalents and investments |
|
|
|
|
|
|
|
|
|
|
|
| Investments, Amortized Cost |
8,853,000 |
|
|
|
1,454,000 |
|
|
|
8,853,000 |
1,454,000 |
|
| Gross Unrealized Losses |
(8,000) |
|
|
|
|
|
|
|
(8,000) |
|
|
| Investments, Estimated Fair Value |
8,845,000 |
|
|
|
1,454,000 |
|
|
|
8,845,000 |
1,454,000 |
|
| Long-term investments | U.S. treasury notes |
|
|
|
|
|
|
|
|
|
|
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| Cash equivalents and investments |
|
|
|
|
|
|
|
|
|
|
|
| Investments, Amortized Cost |
2,494,000 |
|
|
|
9,116,000 |
|
|
|
2,494,000 |
9,116,000 |
|
| Gross Unrealized Gains |
|
|
|
|
3,000 |
|
|
|
|
3,000 |
|
| Gross Unrealized Losses |
(5,000) |
|
|
|
(2,000) |
|
|
|
(5,000) |
(2,000) |
|
| Investments, Estimated Fair Value |
2,489,000 |
|
|
|
9,117,000 |
|
|
|
2,489,000 |
9,117,000 |
|
| Long-term investments | U.S. government agency securities |
|
|
|
|
|
|
|
|
|
|
|
| Cash equivalents and investments |
|
|
|
|
|
|
|
|
|
|
|
| Investments, Amortized Cost |
31,454,000 |
|
|
|
8,187,000 |
|
|
|
31,454,000 |
8,187,000 |
|
| Gross Unrealized Gains |
|
|
|
|
1,000 |
|
|
|
|
1,000 |
|
| Gross Unrealized Losses |
(50,000) |
|
|
|
(5,000) |
|
|
|
(50,000) |
(5,000) |
|
| Investments, Estimated Fair Value |
31,404,000 |
|
|
|
8,183,000 |
|
|
|
31,404,000 |
8,183,000 |
|
| Money market funds |
|
|
|
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|
|
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|
|
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| Cash equivalents and investments |
|
|
|
|
|
|
|
|
|
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| Cash equivalents, Estimated Fair Value |
357,000 |
|
|
|
5,356,000 |
|
|
|
357,000 |
5,356,000 |
|
| Certificates of deposit | Short-term investments. |
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| Cash equivalents and investments |
|
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|
|
|
|
|
|
|
|
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| Investments, Amortized Cost |
2,934,000 |
|
|
|
|
|
|
|
2,934,000 |
|
|
| Investments, Estimated Fair Value |
2,934,000 |
|
|
|
|
|
|
|
2,934,000 |
|
|
| Certificates of deposit | Long-term investments |
|
|
|
|
|
|
|
|
|
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| Cash equivalents and investments |
|
|
|
|
|
|
|
|
|
|
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| Investments, Amortized Cost |
1,848,000 |
|
|
|
238,000 |
|
|
|
1,848,000 |
238,000 |
|
| Investments, Estimated Fair Value |
$ 1,848,000 |
|
|
|
$ 238,000 |
|
|
|
$ 1,848,000 |
$ 238,000 |
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