|
Income taxes (Narrative) (Details) (USD $)
In Thousands, unless otherwise specified |
12 Months Ended | |||
|---|---|---|---|---|
|
Dec. 28, 2013
|
Dec. 29, 2012
|
Dec. 31, 2011
|
Jan. 01, 2011
|
|
| Tax Credit Carryforward, Expiration Date | Jan. 01, 2029 | |||
| Operating Loss Carryforwards, Expiration Dates | 20 | |||
| Valuation Allowance, Amount | $ 6,535 | $ 3,145 | $ 4,547 | $ 5,880 |
| Significant Change in Unrecognized Tax Benefits, Nature of Event Timing | 2015-01-01 | |||
| Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense | 85 | 0 | ||
|
Internal Revenue Service (IRS) [Member]
|
||||
| Open Tax Year | 2006 | |||
|
Canada Revenue Agency [Member]
|
||||
| Open Tax Year | 2006 | |||
|
US | Capital Loss Carryforward [Member]
|
||||
| Operating Loss Carryforwards | 5,108 | 11,517 | ||
|
US | State and Local Jurisdiction [Member]
|
||||
| Operating Loss Carryforwards | 6,576 | 11,311 | ||
|
CA | Capital Loss Carryforward [Member]
|
||||
| Operating Loss Carryforwards | 21,581 | 28,821 | ||
| Other Tax Carryforward, Gross Amount | 394 | 845 | ||
|
Research Tax Credit Carryforward [Member] | US
|
||||
| Tax Credit Carryforward, Amount | 71 | 71 | ||
|
Research Tax Credit Carryforward [Member] | CA
|
||||
| Tax Credit Carryforward, Amount | 953 | 958 | ||
|
Research Tax Credit Carryforward [Member] | MA [Member]
|
||||
| Tax Credit Carryforward, Amount | 166 | 166 | ||
|
Scientific [Member] | CA
|
||||
| Tax Credit Carryforward, Amount | $ 10,098 | $ 10,847 | ||