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Deferred tax reconciliation (Details 5) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Income Tax Disclosure [Abstract] |  |  |
Change in net deferred income tax liability from the preceding table | $ 5,460 |  |
Deferred taxes associated with other comprehensive income | (3,086) |  |
Other | (2,073) |  |
Deferred income taxes | $ 301 | $ 58,990 | $ 28,551

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