|
Marketable Securities (Details) (USD $)
|
12 Months Ended |
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|
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|
Dec. 31, 2014
item
|
Dec. 31, 2013
|
Dec. 31, 2012
|
Dec. 31, 2011
|
| Available-for-sale marketable securities |
|
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|
|
| Cash and cash equivalents, Amortized Cost Value |
$ 28,518,000 |
$ 12,303,000 |
$ 18,653,000 |
$ 25,128,000 |
| Marketable securities, Amortized Cost |
76,779,000 |
|
|
|
| Marketable securities, Gross Unrealized Gains |
12,000 |
|
|
|
| Marketable securities, Gross Unrealized Losses |
(33,000) |
|
|
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| Marketable securities, Fair Value |
76,758,000 |
|
|
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| Cash and cash equivalents, Fair Value |
28,518,000 |
|
|
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| Debt securities held in an unrealized loss position for more than 12 months |
0 |
|
|
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| Debt securities held in an unrealized loss position for less than 12 months |
34 |
|
|
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| Fair value of debt securities in an unrealized position for less than 12 months |
68,900,000 |
|
|
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| Unrealized loss on debt securities in an unrealized loss position for less than 12 months |
34,000 |
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| Maximum |
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| Available-for-sale marketable securities |
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|
|
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| Marketable securities, contractual term to maturity |
1 year |
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| Domestic corporate debt securities |
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|
|
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| Available-for-sale marketable securities |
|
|
|
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| Marketable securities, Amortized Cost |
69,542,000 |
|
|
|
| Marketable securities, Gross Unrealized Losses |
(33,000) |
|
|
|
| Marketable securities, Fair Value |
69,509,000 |
|
|
|
| Domestic corporate commercial paper |
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|
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| Available-for-sale marketable securities |
|
|
|
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| Marketable securities, Amortized Cost |
7,237,000 |
|
|
|
| Marketable securities, Gross Unrealized Gains |
12,000 |
|
|
|
| Marketable securities, Fair Value |
7,249,000 |
|
|
|
| Cash |
|
|
|
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| Available-for-sale marketable securities |
|
|
|
|
| Cash and cash equivalents, Amortized Cost Value |
1,519,000 |
|
|
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| Cash and cash equivalents, Fair Value |
1,519,000 |
|
|
|
| Money market |
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|
|
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| Available-for-sale marketable securities |
|
|
|
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| Cash and cash equivalents, Amortized Cost Value |
23,994,000 |
|
|
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| Cash and cash equivalents, Fair Value |
23,994,000 |
|
|
|
| Domestic corporate debt securities |
|
|
|
|
| Available-for-sale marketable securities |
|
|
|
|
| Cash and cash equivalents, Amortized Cost Value |
3,005,000 |
|
|
|
| Cash and cash equivalents, Fair Value |
$ 3,005,000 |
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