|
Income taxes - Narrative (Details) (USD $)
|
12 Months Ended |
|---|---|
|
Dec. 31, 2012
|
|
| Operating Loss Carryforwards [Line Items] | |
| Increase In Valuation Allowance | $ 496,000 |
|
Internal Revenue Service (IRS)
|
|
| Operating Loss Carryforwards [Line Items] | |
| Operating Loss Carryforwards | 8,500,000 |
|
Internal Revenue Service (IRS) | Subsidiary
|
|
| Operating Loss Carryforwards [Line Items] | |
| Operating Loss Carryforwards | $ 1,900,000 |
| X | ||||||||||
|
- Definition
The sum of domestic, foreign and state and local operating loss carryforwards, before tax effects, available to reduce future taxable income under enacted tax laws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The amount of the change in the period in the valuation allowance for a specified deferred tax asset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|