v3.8.0.1

Fair value measurement (Details) - Recurring basis - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Money market accounts	$ 2,255	$ 2,239
Total assets	2,255	2,239
Level 1
Assets:
Money market accounts	2,255	2,239
Total assets	2,255	2,239
Level 2
Assets:
Money market accounts	0	0
Total assets	0	0
Level 3
Assets:
Money market accounts	0	0
Total assets	$ 0	$ 0

X

- 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=66048111&loc=d3e19207-110258

+ Details

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X

- References

No definition available.

+ Details

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X

- 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

No definition available.

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