Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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Income taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
Income taxes (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2017
Income taxes [Abstract]
Income tax provision	$ (26)	$ 305	$ 89	$ 483
Effective tax rate	(16.30%)	20.10%	8.70%	20.40%
Unrecognized tax benefits that would favorably affect effective income tax rate if recognized	$ 104		$ 104
Unrecognized tax benefits that will lapse upon expiration of statute of limitations	25
Accrued interest and penalties related to uncertain tax positions	$ 23		$ 23
U.S. corporate income tax rate					34.00%
Maximum [Member]
Income taxes [Abstract]
U.S. corporate income tax rate					35.00%