Fair Value Measurements (Details) - Recurring - Total - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets:
Restricted cash	$ 260	$ 260
Total assets	59,082	73,748
Cash
Assets:
Cash and cash equivalents	6,702	16,887
Money market funds
Assets:
Cash and cash equivalents	52,120	56,601
Level I
Assets:
Restricted cash	260	260
Total assets	59,082	73,748
Level I \| Cash
Assets:
Cash and cash equivalents	6,702	16,887
Level I \| Money market funds
Assets:
Cash and cash equivalents	52,120	56,601
Level 2
Assets:
Restricted cash	0	0
Total assets	0	0
Level 2 \| Cash
Assets:
Cash and cash equivalents	0	0
Level 2 \| Money market funds
Assets:
Cash and cash equivalents	0	0
Level 3
Assets:
Restricted cash	0	0
Total assets	0	0
Level 3 \| Cash
Assets:
Cash and cash equivalents	0	0
Level 3 \| Money market funds
Assets:
Cash and cash equivalents	$ 0	$ 0

Fair value portion of cash and equivalents whose use in whole or in part is restricted for the long-term, generally by contractual agreements or regulatory requirements.

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
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- References

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- Definition

Fair value portion 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.

+ References

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

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash Equivalents
-URI http://asc.fasb.org/extlink&oid=6507016

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