Income taxes - Narrative (Details) - Internal Revenue Service (IRS) |
Dec. 31, 2016
USD ($)
|
|---|---|
| Operating Loss Carryforwards [Line Items] | |
| Operating Loss Carryforwards | $ 19,099,000 |
| Subsidiary | |
| Operating Loss Carryforwards [Line Items] | |
| Operating Loss Carryforwards | $ 981,000 |
| X | ||||||||||
- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- 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. No definition available.
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|