Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018
Accumulated other comprehensive income (loss)
Reclassification adjustment for (gains) losses on available-for-sale debt securities	$ (13)	$ 2,473

Amount before tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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