6. Income taxes (Details)	Jun. 30, 2016 USD ($)
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 114,000

The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65882285&loc=SL6600010-109319

Name:	us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant