Short-term investments - Securities and Investments, Recorded at Fair Value (Details) - USD ($) $ in Thousands |
Dec. 30, 2017 |
Dec. 31, 2016 |
|---|---|---|
| Available-for-sale Securities, Amortized Cost Basis [Abstract] | ||
| Amortized Cost | $ 9 | $ 32 |
| Unrealized Gains | 0 | 0 |
| Unrealized Losses | 0 | (2) |
| Fair Value | $ 9 | $ 30 |
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- Definition Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in equity securities classified as available-for-sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in equity securities classified as available-for-sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition This item represents the cost of equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments for other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. No definition available.
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| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition Amount of equity securities categorized neither as held-to-maturity nor as trading. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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