Income taxes, Unrecognized tax benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income taxes [Abstract]
Unrecognized tax benefits that would favorably affect effective income tax rate if recognized	$ 144	$ 121
Unrecognized tax benefits [Roll Forward]
Unrecognized tax benefits, beginning of period	121	107
Tax positions taken during the current period	47	41
Lapse of statute of limitations	(24)	(27)
Unrecognized tax benefits, end of period	144	121
Expected decrease in unrecognized tax benefits in next year	28
Accrued interest and penalties related to uncertain tax positions	$ 20	$ 19