Represents amount of transfers between fair value measurement levels.

No definition available.

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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- References

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- References

No definition available.

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- Definition

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6506951

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2014
Financial Instruments
Transfers Between Fair Value Measurement Levels	$ 0		$ 0
Cash and cash equivalents:
Cash and cash equivalents	31,795	$ 23,596	$ 23,818	$ 62,780
Available-for-Sale Securities:
Available-for-sale securities	0	14,931
Corporate debt securities
Available-for-Sale Securities:
Available-for-sale securities		13,930
U.S. government-sponsored securities
Available-for-Sale Securities:
Available-for-sale securities		1,001
Recurring
Assets:
Total assets	29,469	37,354
Recurring \| Money market funds
Cash and cash equivalents:
Cash and cash equivalents	25,671	22,423
Recurring \| Corporate debt securities
Available-for-Sale Securities:
Available-for-sale securities	3,798	13,930
Recurring \| U.S. government-sponsored securities
Available-for-Sale Securities:
Available-for-sale securities		1,001
Recurring \| Level 1
Assets:
Total assets	25,671	22,423
Recurring \| Level 1 \| Money market funds
Cash and cash equivalents:
Cash and cash equivalents	25,671	22,423
Recurring \| Level 2
Assets:
Total assets	3,798	14,931
Recurring \| Level 2 \| Corporate debt securities
Available-for-Sale Securities:
Available-for-sale securities	$ 3,798	13,930
Recurring \| Level 2 \| U.S. government-sponsored securities
Available-for-Sale Securities:
Available-for-sale securities		$ 1,001